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3
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第 1åè¬çŸ© 7
1.1 ã€ã³ãããã¯ã·ã§ã³ â ãŠã©ãŒãã³ã°ã¢ãã â . . . . . . . . . . . . . . . . . . . . . . . . 71.1.1 ããã§æ±ããã°ã©ãããšã¯ãã£ããäœã ? . . . . . . . . . . . . . . . . . . . . . . . 71.1.2 æ§ã ãªã°ã©ããšãã®äŸ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
第 2åè¬çŸ© 172.1 å®çŸ©ãšäŸ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.1.1 åçŽã°ã©ã . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172.1.2 å圢 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182.1.3 ã©ãã«ä»ãã°ã©ããšã©ãã«ãªãã°ã©ã . . . . . . . . . . . . . . . . . . . . . . . . . 192.1.4 é£çµã°ã©ã . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192.1.5 次æ°ããã³æ¬¡æ°å . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192.1.6 éšåã°ã©ã . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202.1.7 è¡åã«ããã°ã©ãã®è¡šçŸæ¹æ³ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
第 3åè¬çŸ© 39
3.1 æ§ã ãªã°ã©ãã®äŸ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393.1.1 空ã°ã©ã . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393.1.2 å®å šã°ã©ã . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393.1.3 æ£åã°ã©ã . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393.1.4 éè·¯ã°ã©ã . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403.1.5 éã°ã©ã . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403.1.6 è»èŒª . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403.1.7 ããŒã¿ãŒã¹ã³ã»ã°ã©ã . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413.1.8 äºéšã°ã©ã . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413.1.9 å®å šäºéšã°ã©ã . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413.1.10 k-ç«æ¹äœ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423.1.11 åçŽã°ã©ãã®è£ã°ã©ã . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
3.2 ã°ã©ãã«ãŸã€ããããã€ãã®ããºã« . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423.2.1 8ã€ã®åã®é 眮åé¡ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433.2.2 4ã€ã®ç«æ¹äœããºã« . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
第 4åè¬çŸ© 63
4.1 éãšéè·¯ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 634.1.1 é£çµæ§ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 634.1.2 éé£çµåéåãšåé¢éå . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
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第 5åè¬çŸ© 835.1 ãªã€ã©ãŒã»ã°ã©ããšããã«ãã³ã»ã°ã©ã . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
5.1.1 ãªã€ã©ãŒã»ã°ã©ã . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 835.1.2 ããã«ãã³ã»ã°ã©ã . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
第 6åè¬çŸ© 103
6.1 æšãšãã®æ°ãäžã . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1036.1.1 æšã®åºæ¬çãªæ§è³ª . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1036.1.2 å šåæš . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1046.1.3 åºæ¬éè·¯éåãšåºæ¬ã«ããã»ããéå . . . . . . . . . . . . . . . . . . . . . . . . . 105
第 7åè¬çŸ© 1136.1.4 æšã®æ°ãäžã . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1136.1.5 ç¹è¡åãšè¡åæšå®ç . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
第 8åè¬çŸ© 139
8.1 å¹³é¢æ§ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1398.1.1 å¹³é¢ã°ã©ããšãªã€ã©ãŒã®å ¬åŒ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1398.1.2 亀差æ°ãšåã . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
第 9åè¬çŸ© 157
8.1.3 å察ã°ã©ã . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1578.2 ã°ã©ãã®åœ©è² . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
8.2.1 ç¹åœ©è² . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
第 10åè¬çŸ© 1738.2.2 å°å³ã®åœ©è² . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1738.2.3 èŸºåœ©è² . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1758.2.4 圩è²å€é åŒ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
第 11åè¬çŸ© 1959.1 æåã°ã©ã . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
9.1.1 æåã°ã©ãã®å®çŸ©ã»æŠå¿µãšãã®æ§è³ª . . . . . . . . . . . . . . . . . . . . . . . . . . . 1959.1.2 ãªã€ã©ãŒæåã°ã©ããšããŒãã¡ã³ã . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
第 12åè¬çŸ© 2099.1.3 ãã«ã³ãé£é . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
第 13åè¬çŸ© 221
10.1 ãããã³ã°, çµå©, Menger ã®å®ç . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22110.1.1 Hallã®çµå©å®ç . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22110.1.2 暪æçè« . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22210.1.3 暪æãšçµå©åé¡, åã³, Hallã®å®çãšã®é¢ä¿ . . . . . . . . . . . . . . . . . . . . . . . 22210.1.4 Hallã®å®çã®å¿çšäŸ : ã©ãã³æ¹é£ . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22310.1.5 Mengerã®å®ç . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224
10.2 ãããã¯ãŒã¯ãã㌠. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22510.2.1 æ倧ãããŒã®é次æ§ææ³ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22710.2.2 æ倧ãããã³ã°ãžã®é©çš . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228
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2004幎床 ææ«è©Šéšè§£ç (æ å ±å·¥åŠç§ 3幎ç/é»åå·¥åŠç§ 4幎ç) 237
2005幎床 ææ«è©Šéš (æ å ±å·¥åŠç§ 3幎ç/é»åå·¥åŠç§ 4幎ç) 241
2005幎床 ææ«è©Šéšè§£ç (æ å ±å·¥åŠç§ 3幎ç/é»åå·¥åŠç§ 4幎ç) 243
2005幎床 ææ«è©Šéšç·è© (æ å ±å·¥åŠç§ 3幎ç/é»åå·¥åŠç§ 4幎ç) 247
2006幎床 ææ«è©Šéš (æ å ±å·¥åŠç§ 3幎ç/é»åå·¥åŠç§ 4幎ç) 249
2006幎床 ææ«è©Šéšè§£ç (æ å ±å·¥åŠç§ 3幎ç/é»åå·¥åŠç§ 4幎ç) 251
2006幎床 ææ«è©Šéšç·è© (æ å ±å·¥åŠç§ 3幎ç/é»åå·¥åŠç§ 4幎ç) 255
2007幎床 ææ«è©Šéš (é»åå·¥åŠç§ 4幎ç) 257
2007幎床 ææ«è©Šéšè§£ç (é»åå·¥åŠç§ 4幎ç) 261
2007幎床 ææ«è©Šéšç·è© (é»åå·¥åŠç§ 4幎ç) 267
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第1åè¬çŸ©
1.1 ã€ã³ãããã¯ã·ã§ã³ â ãŠã©ãŒãã³ã°ã¢ãã â
ãŸãã¯æ¬è¬çŸ©ã§æ±ããã°ã©ããã®å®çŸ©ããå§ã, æ¬è¬çŸ©ã§ç¿ãäºé ãæŠèŠ³ããããšã«ããã. ããããã®æŠå¿µã®è©³çŽ°ããã³å¿çšäŸã¯åãé²ããããšã«è¿œã èŠãŠè¡ãããšã«ãªã.è¬çŸ©ãé²ãããã¡ã«å¹Ÿã€ãã®å®ç, ç³», è£é¡ãåºãŠããã, æ¬è¬çŸ©ã§ã¯ãããã®äžã§æ¯èŒçéèŠãšæãã
ããã®ã«é¢ããŠã¯, ãã®èšŒæãè¿œã£ãŠã¿ãã, ãã以å€ã®ãã®ã«é¢ããŠã¯, å ·äœçãªäŸ/å¿çšäŸãåãäžã,è«žå®çã®æå³ãçŽèŠ³çã«ç解ã, æçšæ§ã確èªããã«ãšã©ãã. è¬çŸ©ã§åãäžããªãã£ã蚌æã«é¢ããŠã¯åèªãæç§æž/åèå³æžçãèªã¿, å¿ ãäžåºŠã¯ãã®æµããè¿œã£ãŠã¿ãããš.éäžã«çŸããäŸé¡ *.* ã¯åæµ·é倧åŠå·¥åŠéšæ å ±å·¥åŠç§ (éžæç§ç®ãšããŠé»åå·¥åŠç§)ã«ãããŠéå» 5幎é
(2002ïœ2007幎床) ã«ãããåœè¬çŸ© (ããã³, æ å ±å·¥åŠæŒç¿ II(B))㧠æŒç¿åé¡ ãšããŠåºé¡ããããã®ã«è§£
ç/解説ãã€ãããã® (å Žåã«ãã£ãŠã¯è£å©åé¡/çºå±åé¡ãã€ããŠãã)ã§ãã. æéã®éœåäž, è¬çŸ©æéå ã«ã¯åãäžããããšã®ã§ããªããã®ãããã, åèªããããã®äŸé¡ãšãã®è§£çãäžåºŠã¯è¿œã£ãŠããããš.ã°ã©ãçè«ã®ç解ã«ã¯ã§ããã ãå€ãã®äŸé¡ã«ããã, 沢山ã®ã°ã©ããèªåã§å®éã«æããªããåé¡ã解ãããšãéèŠã§ããããã«æã.
â» ããããæ¯åã® æŒç¿åé¡ ã«å¯Ÿã, ãã¡ãã瀺ãã解çäŸãšã¯ç°ãªã£ãå¥è§£æ³ã®æ瀺ãã³ã¡ã³ã, 解ç
äŸã«ããã誀æ€, ééãçã®ææãããŠé ãã, äžéšã®ç±å¿ãªåè¬çã®çããã«æè¬ããŸã.
1.1.1 ããã§æ±ããã°ã©ãããšã¯ãã£ããäœã ?
ã°ã©ãã«é¢ãã詳ãã説æãå§ããåã«, ãŠã©ãŒãã³ã°ã¢ãããšããŠåºæ¬çãªæŠå¿µãæŠèŠ³ããããšã«ãã. ã©ã®ç§ç®ã§ãããã§ããã, ã°ã©ãçè«ã«ãããŠã, ã¯ããã«èŠããªããã°ãªããªã幟ã€ãã®çšèªãå®çŸ©ããã. 決ããŠé£ããã¯ãªãã, ããããæç§æžãè¬çŸ©ããŒã, ãããã¯ããé²ãã å°éæž, è«æçãèªã¿é²ããã«ãããæ¯éãã§ãªãããã«, ãã®æ®µéã§ãã¡ããšæŒãããŠããããšãæ £çšã§ãã.
ç¹, 蟺, 次æ°
ã°ã©ããšãããšæã ã®ãã€ã€ã¡ãŒãžãšããŠã¯ç©çå®éšãªã©ã§ã銎æã¿ã®é床ã®æéçãªå€åãè¡šããã°
ã©ãã, äŒæ¥ã®å¹ŽåºŠå¥åçãªã©ãè¡šããæ£ã°ã©ãããªã©ãæãæµ®ãã¶ã, ã°ã©ãçè«ã§æ±ãã°ã©ãã¯ããããšã¯ç°ãªã, ç¹ããã³èŸºãããªã, ããæœè±¡çãªå¹ŸäœåŠå³åœ¢ã§ãã.
â ã°ã©ã ã»ã»ã»ç¹ (vertex) (å³ 1.1ã® P,Q,R,S,T) , åã³, 蟺 (edge) (å³ 1.1ã® PQ,QR ç) ãããªãå³åœ¢.â æ¬¡æ° (degree) ã»ã»ã» ããç¹ã端ç¹ãšãã蟺ã®æ¬æ°.
äŸ : å³ 1.1ã®ç¹ Pã®æ¬¡æ°ã¯ 3. å³ 1.1ã®ç¹ Qã®æ¬¡æ°ã¯ 4.
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å³ 1.1: ãã®è¬çŸ©ã§æ±ããã°ã©ããã®äžäŸ. ããã®ã°ã©ãã®ç¹æ°ã¯ n = 5, 蟺æ°ã¯ m = 8 ã§ãã, ããããã®ç¹ã®æ¬¡æ°ã¯ deg(P) =deg(T) = 3, deg(Q) = deg(S) = 4, deg(R) = 2 ã§ãã.
ãããåŒã§è¡šããšæ¬¡ã®ããã«æžãã1 . ã°ã©ãã«ããã次æ°ãšã¯, äžèšã®ããã« P,Qã®ããã«ç¹ãæå®ããŠåããŠå®çŸ©ãããéã§ããããšã«æ³šæããã.{
deg(P) = 3deg(Q) = 4
(1.1)
ã°ã©ãã«æå³ãæããã
æã ã¯ä»ãŸã§ã«ãç¡æèã®ãã¡ã«äžèšã®ãããªã°ã©ããçšããŠå®åé¡ãè¡šããŠãã. äŸãã°, å³ 1.1 ã®P,Q,R,R,T ã»ã»ã»ãããããŒã«ããŒã â åç¹ã®æ¬¡æ°ããã®ããŒã ãè¡ãè©Šåæ°ãšãªã. ããããããšã«ãã£ãŠ, æ Œæ®µã«å¯Ÿè±¡ã«å¯ŸããèŠéããè¯ããªãããã§ããã, äŸãã°, ãã®ã°ã©ãããç¹ Pã®æ¬¡æ°ã確èªããã
ãšã§ãdeg(P) = 3 â ããŒã Pãè¡ãè©Šåæ°ã¯ 3ã§ãããã®ããã«æçãªæ å ±ãåŸãããšãã§ãã. ã°ã©ãçè«ã§ã¯ããããèŠæ¹ãäœç³»ç«ãŠãŠåŠãã§ãã.
â» ãã®ä»ã«ã, é»æ°åè·¯, éè·¯ç, æ§ã ãªåœ¢ã§ã°ã©ãã«æå³ãæãã, ãã®å¯Ÿè±¡ãã°ã©ãçè«çãªèå¯ã«åºã¥ã調ã¹ãããšãã§ãã. â äŸé¡ 1.1 2,3 åç §.
ã°ã©ãã®å圢æ§
ã°ã©ããšã¯ç¹ã®éåãšãããã®çµã³æ¹ (蟺ã®éå)ã®è¡šçŸã§ãã, è·é¢çãªæ§è³ªãšã¯ç¡é¢ä¿ã§ãã. äŸãã°, äžèšã® 2ã€ã®å³åœ¢ã¯ã°ã©ãçè«ã«ãããŠã¯åããã®ãšããŠæ±ããã. åŸã£ãŠ, å®åé¡ãã°ã©ãã§è¡šçŸã
P Q
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R P
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å³ 1.2: å圢㪠2 ã€ã®ã°ã©ãã®äžäŸ. 蟺ãé©åã«ç§»åããããšã«ãã, å·Šå³ããå³å³ãåŸãããããšãåèªã確èªããŠã¿ããšãã.
ãéã«ã¯æ±ãããããã® (調ã¹ããé¢ä¿æ§ãèŠããããã®)ãéžã¶ããšãèèŠã§ãã. åŸã«ã¿ãã, ããæ°åŠçã«ã¯ 2ã€ã®ã°ã©ã A, Bãå圢ãåŠãã¯, å圢ååãšåŒã°ãã Aã®ç¹ãš Bã®ç¹ã®éã®äžå¯Ÿäžå¯Ÿå¿ãå
åšãããåŠãã§å€å®ããã2 .1 ç¹ (é ç¹) ã®åæ°ããã®è¬çŸ©ããŒãã§ã¯ãç¹æ°ããšåŒã³, äŸãã°, 5 åã®æ°ãããªãæã€ã°ã©ãã®ç¹æ°ã n = 5 ãšè¡šèšããã, æç§æžã«ãã£ãŠã¯, ãã®æ°ãäœæ°ãšåŒã³, ã°ã©ã Gã®äœæ°ã |G|ãšè¡šããã®ãå€ã (ãŸã, 蟺æ°ã¯ ||G||ãšè¡šãå Žåããã). ãã®ããã«, åãã°ã©ãçè«ã®èšå·ã§ãæç§æžãæç®ã«ãã£ãŠã¯ç°ãªãèšå·, åŒã³æ¹ãããå Žåããã, ãããååŠæã®æ©ã¿ã®çš®ãšãªã£ãŠãã. æ¬è¬çŸ©ã§ã¯äžè²«ããåŒã³æ¹, èšå·ã䜿ãã®ã§åé¡ã¯ãªãã, è¿ãå°æ¥, ããé²ãã åŠç¿ãããéã«ã¯æ³šæãå¿ èŠã§ãã.
2 å圢㪠2 ã€ã®ã°ã©ãã«åãå€ãäžãããããã®ãã°ã©ãã®äžå€éãšåŒã³, ç¹æ°ãå€æ°ã¯ãã®äžå€éã®äžã€ã§ãã.
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â»ã°ã©ãã®è¡šçŸã«ã¯å³ 1.2ã®ãããªç¹ãšç·ã«ããæç»ã®ä»ã«, é£æ¥è¡å, æ¥ç¶è¡åçã®è¡åãçšããããšãã§ãã. ãã®è¡šçŸæ³ã¯èšç®æ©äžã§ã°ã©ããæ±ãããã«ã¯æçšã§ãã. ãããã®è¡åã«é¢ãã詳现ã¯æ¬¡å以éã«èŠãŠè¡ãããšã«ãªã.
1.1.2 æ§ã ãªã°ã©ããšãã®äŸ
å šãŠã®ã°ã©ãã¯ãã®å¹ŸäœåŠçãªæ§è³ªã®éãããã°ã«ãŒãã«åé¡ãã, ããããã®ã°ã«ãŒãã«ã¯ååãä»ããããŠãã. ããã§ã¯, ãã®äžã®ããã€ããæŠèŠ³ãã.
å€é蟺, ã«ãŒã, åçŽã°ã©ã
â å€é蟺 (multiple edges) ã»ã»ã»ä»»æã® 2ç¹ P,Qã 2æ¬ä»¥äžã®èŸºãçµãã§ããå Žå, ãããå€é蟺ãš
P T
S
Q
R
å³ 1.3: ãã®å³ã«ãããŠ, 蟺 TS, QS ã¯å€é蟺ã§ãã, ç¹ P ã«ã¯äžã€ã®ã«ãŒãããã.
åŒã¶.â ã«ãŒã (loop) ã»ã»ã»ä»»æã®ç¹ Pãã Pèªèº«ãžæ»ã蟺
â åçŽã°ã©ã (simple graph) ã»ã»ã»å€é蟺ãã«ãŒããå«ãŸãªãã°ã©ã
æåã°ã©ã
â æåã°ã©ã (directed graph : digraph ãšåŒã°ããããšãå€ã)ã»ã»ã»èŸºã«åããäžããããã°ã©ã
P T
Q
S
R
å³ 1.4: æåã°ã©ãã®äžäŸ. å蟺ã«åããæãããããšã«ãã, ä»»æã® 2 ç¹éã®é¢ä¿æ§ (äŸãã°, P 㯠Q ã«å¥œæãæã£ãŠããç) ãæ瀺ãããããšãã§ãã.
â æ©é (walk) ã»ã»ã»é£çµãã蟺ã®å.
ãã㯠9ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
â é (path) ã»ã»ã»ã©ã®ç¹ãé«ã äžåºŠããçŸããªãæ©é.â éè·¯ (cycle) ã»ã»ã»å³ 1.2ã®å³åŽã® Q â S â T â Q ã®ãããªé.
â» æåã°ã©ããçšããäŸãšããŠã¯äŸé¡ 1.1ã® 2ãåç §.
é£çµã°ã©ããšéé£çµã°ã©ã
ãå šéšã€ãªãã£ãŠãããããã€ãªãã£ãŠãªãããã§ã°ã©ããåé¡ããããšãã§ãã.
P Q
S R
T
V
U
å³ 1.5: éé£çµã°ã©ãã®äžäŸ. æåæ°ã¯ 2 ã§ãã.
â é£çµã°ã©ã (connected graph) ã»ã»ã»ã©ã® 2ã€ã®ç¹ãéã§çµã°ããŠããã°ã©ã.â éé£çµã°ã©ã (disconnected graph) ã»ã»ã»é£çµã°ã©ãã§ã¯ãªãã°ã©ã (å³ 1.5åç §).
â» éé£çµã°ã©ããæ§æããåé£çµã°ã©ããæå (component)ãšåŒã¶. å³ 1.5ã®äŸã§ã¿ããªãã°, ããã®éé£çµã°ã©ã㯠2ã€ã®æåãæã€ããšããããšã«ãªã.
ãªã€ã©ãŒã»ã°ã©ããšããã«ãã³ã»ã°ã©ã
ã°ã©ãã«ã¯ãã®èæ¡è ã®ååãä»ãããããã®ãå€ã. ããã«åºãŠãã 2ã€ã®ã°ã©ã : ãªã€ã©ãŒã»ã°ã©ã, ããã«ãã³ã»ã°ã©ãã¯ãããã®äžã§æãæåãªãã®ã§ãã.
P Q
R
ST
(1)
(2)
(3)
(4)
(5)
P Q
R
ST
(1)
(2)
(3)
(4)
(5)
(6)
(7)
å³ 1.6: ãã®å³ã¯ããã«ãã³ã»ã°ã©ãã§ã¯ããã (å·Šå³), ãªã€ã©ãŒã»ã°ã©ãã§ã¯ãªã (å³å³).
â ãªã€ã©ãŒã»ã°ã©ã (Eulerian graph)ã»ã»ã»å šãŠã®èŸºãã¡ããã© 1åãã€éã£ãŠåºçºç¹ã«æ»ãæ©éãå«ãã°ã©ã.â ããã«ãã³ã»ã°ã©ã (Hamiltonian graph)ã»ã»ã»å šãŠã®ç¹ãã¡ããã© 1åãã€éã£ãŠåºçºç¹ã«æ»ãæ©éãå«ãã°ã©ã.
â» é£çµã°ã©ãã®ç¹ã®æ°ãå€ãå Žå, ãã®ã°ã©ãããªã€ã©ãŒã»ã°ã©ãã, ããã«ãã³ã»ã°ã©ãã§ããã, ãå®
ãã㯠10ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
éã«è©²åœããæ©éãèŠã€ããããšã«ãã£ãŠå€å®ããã®ã¯å®¹æãªããšã§ã¯ãªã. ãã®ãããªãšã, äžããããé£çµã°ã©ãããªã€ã©ãŒã»ã°ã©ãã§ããããã®æ¡ä»¶, ããã«ãã³ã»ã°ã©ãã§ããããã®æ¡ä»¶ (ããã¯ååæ¡ä»¶)ãç¥ãããŠãã, ãããã Euler (ãªã€ã©ãŒ)ã®å®ç, Ore (ãªãŒã¬)ã®å®çãšããŠãŸãšããããŠãã. ããããçšããããšã«ãã, äžããããé£çµã°ã©ãã®ãªã€ã©ãŒæ§, ããã«ãã³æ§ãå€å®ããããšãã§ããããã«ãªã. ãããã¯åŸã«è©³ããåŠã¶3 .
æš
å³ 1.7: æšã®äžäŸ.
â æš (tree) ã»ã»ã»ã©ã® 2ç¹ã®éã«ãéã 1æ¬ãããªãé£çµã°ã©ã (å³ 1.7åç §).â» ã¯ãŒã¯ã¹ããŒã·ã§ã³ã®ãã¡ã€ã«ã·ã¹ãã , çç©é²åã®ç³»çµ±å³ãªã©ã¯æšæ§é ãæã€.
3 ãªã€ã©ãŒéè·¯ã®åé¡ã¯ã±ãŒããã¹ãã«ã° (çŸã«ãŒãã³ã°ã©ãŒã) ã®è¡ã«ããæ©ã 1 åãã€éã£ãŠããšã«ãã©ãåé¡ãæ°åŠè ãªã€ã©ãŒãèããããšã«ç±æ¥ããããã. ã«ãŒãã³ã°ã©ãŒãã¯ããŒã©ã³ãã«è¿ãæ±æ¬§ã®ãã·ã¢é ãããã, ãã£ããã°ã©ãçè«ã§åŠãã ããã ãã, å®éã«ã©ã®ãããªæ©ã®é 眮ã ã£ãã®ãã確ããã«çŸå°ãäžåºŠèšªããŠã¿ãããããªæ°ãããŠãã.
ãã㯠11ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäžï¿œ
ᅵ
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ãäŸé¡ 1.1ã (2004幎床 æŒç¿åé¡ 1 )
1. ååŠåŒ C5H12 ãæã€ååã«ã¯ããã€ãã®æ§é ã®ç°ãªãååãååšãã (ãæ§é ç°æ§äœã). ãããã®ååãå šãŠæã, å³ (CH4)ã«åŸã£ãŠ, ããããã«å¯Ÿå¿ããã°ã©ããæã.
C
H
H
H
H
2. John㯠Joanã奜ãã§, Jean㯠Janeã奜ãã§, Joe㯠Jeanãš Joan ã奜ãã§, Jeanãš Joan ã¯
äºãã«å¥œãã§ãã. John, Joan, Jean, Jane åã³ Joe ã®éã®é¢ä¿ã説æããæåã°ã©ããæã.3. a,b,c,d,e,fã® 6ããŒã ã§ããã±ãŒã®è©Šåãããããšã«ãªã£ã. åããŒã ã®è¡ã£ãè©Šåæ°ã¯
ããŒã å a b c d e f
è©Šåæ° 2 2 4 4 3 1
ã§ãã£ã. ãã®ãšã, èãåŸãè©Šåã®çµã¿åãããã°ã©ãã§è¡šã, ããããå šãŠæã. ãã ã,åäžã«ãŒã㯠2è©Šå以äžè¡ããªããã®ãšãã.
(解çäŸ) :
1. ã°ã©ãçè«çã«ãã®åé¡ãèšãæããŠã¿ããš, åé¡ã§ãããCnH2n+2 ã®æ§é ç°æ§äœã®æ°ãæ°ãããã
ãšã¯, ãnåã®ç¹ã®æ¬¡æ°ã 4ã§ãã, æ®ãã® 2n + 2åã®ç¹ã®æ¬¡æ°ã 1ã§ãããã©ãã«ãªãæšãã®ç·æ°ãæ°ããããšããããšã«ãªã.ççŽ ååå士ã®ã€ãªãæ¹ã決ããã°, æ°ŽçŽ ååã®é 眮ã®ä»æ¹ã¯èªåçã«æ±ºãŸãã®ã§, å¯èœãªççŽ ååã®é 眮ãæ°ããããŠè¡ãã°ãã. å³ 1.8(å·Š) ã«ãã®çµæãèŒãã.
c c c c c
cc c
c
c
c c c c
c
A
B
C
c c c c c
cc c
c
c
c c c c
c
A
B
C
H H H H H
H H H H H
H H
H
H HH
H
HH
H
HH
H
H
H H H H
H
HH
H
H
H
H
H
å³ 1.8: n = 5 ã®å Žåã«å¯èœãªççŽ ååé å (å·Š). ãªã, A ã¯ããã³ã¿ã³ã, B ã¯ã2-2-ãžã¡ãã«ãããã³ã, C ã¯ã2-ã¡ãã«ãã¿ã³ããšåŒã°ããææ©ååç©ã§ãã. ãŸã, å³å³ã¯ C5H12 ã®æ§é ç°æ§äœ.
åŸã£ãŠ, æ±ããæ§é ç°æ§äœã¯äžèšã®ççŽ ååã®æ®ãã®æã«æ°ŽçŽ ååãä»å ããã°ãã, çãã¯äžã®å³1.8(å³)ã®ããã«ãªã.
ãã㯠12ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
⻠泚 : æ±ããã°ã©ãã¯ãæšãã§ãªããã°ãªããªã (ã€ãŸã, ã©ã® 2ç¹éã«ãéã 2æ¬ä»¥äžååšããŠã¯ãªããªã)ã®ã§, å³ 1.9ã®ãããªé 眮ã¯èš±ããã, å®é, ãã®ççŽ é åã§æ°ŽçŽ ååã䞊ã¹ãŠã¿ããš C5H10
ãšãªã, C5H12 ãšã¯ç°ãªããã®ãåºæ¥äžãã£ãŠããŸã. 4
c c
c
c
c
H H H H
H
H
H
H
H H
å³ 1.9: C5H10.
2. æ±ããæåã°ã©ã㯠(奜æãæã£ãŠãã人ç©) â (奜æãæãããŠãã人ç©) ã®ããã«ç¢å°ãã€ããçŽæã«ãããšå³ 1.10(å·Š)ã®ããã«ãªã.
Jane Jean
Joe
Joan
John
b
c
d
e
fa b
c
d
e
af
b
c
d
e
fa
b
c
d
e
fa
b
c
d
e
a f
å³ 1.10: John, Joan, Jean, Jane åã³ Joe ã®é¢ä¿å³ (å·Š). èãåŸã察æŠã«ãŒããè¡šã 5 çš®é¡ã®ã°ã©ã (å³).
3. èãåŸãçµã¿åããã®ã°ã©ãã¯å³ 1.10(å³)ã®ããã« 5éããã.
ᅵ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 1.2ã (2005幎床 æŒç¿åé¡ 1 )
(1)ç¹ã®éåã V = {v1, v2, v3, v4, v5, v6} ã§äžããã, ãã€, 蟺ã®éåã E ={v1v3, v2v3, v3v4, v4v1, v4v3, v5v6}ãããªãã°ã©ããæã.
(2)ããã¯ã«ãšã«ãé£ã¹, ããªã¯ã¯ã¢ãé£ã¹ã. ããªãšã¯ã¢ã¯ã©ã¡ããè«ãé£ã¹ã. ã«ãšã«ã¯ã«ã¿ãã ãª, ã¯ã¢, ããã³, è«ãé£ã¹ã. ãã®æé£è¡åãè¡šãæåã°ã©ããæã.
(解çäŸ)ç°¡åãªã®ã§çµæã ãæã.
(1)åçŽã°ã©ããšã¯æ瀺ãããŠããªãã®ã§, å³ 1.11 (å·Š) ã®ãããªå€é蟺ãå«ãéé£çµãªã°ã©ããšãªã.(2)ååã s(ãžã³), f(ã«ãšã«), sn(ã«ã¿ãã ãª), sp(ã¯ã¢), b(ããª), i(è«) ãšã, (é£ã¹ããã®) â (é£ã¹ããããã®) ã®ããã«ç¢å°ãæãçŽæã«ããã°, å³ 1.11 (å³) ã®ããã«ãªã.
4 系統çãªæšã®æ°ãäžãã«é¢ããŠã¯åŸã« Cayley (ã±ã€ãªãŒ) ã®å®çã§åŠã¶ããšã«ãªããŸã.
ãã㯠13ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
v1
v4
v3 v2
v5
v6
s
sn
f
sp
i
b
å³ 1.11: å€é蟺ã®ããæåãå«ã, éé£çµã°ã©ã (å·Š). æé£é¢ä¿ãè¡šãæåã°ã©ã (å³).
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ãäŸé¡ 1.3ã (2006幎床 æŒç¿åé¡ 1 )
以äžã®åãã«çãã.
(1)身ã®åãã®äºæã§, ããããæšãã®ã°ã©ãã§è¡šçŸã§ãããã®ãäžã€æãã.(â» ãã ã, è¬çŸ©ã§åãäžããã¯ãŒã¯ã¹ããŒã·ã§ã³ã®ãã¡ã€ã«ã·ã¹ãã , çç©é²åã®ç³»çµ±å³, ææ©ååç©ã®æ§é 以å€ãéžã¶ããš)
(2)ã©ã®èŸºã® 2ã€ã®ç«¯ç¹ãç°ãªãéå (ã°ã«ãŒã)ã«å±ããããã« nåã®ç¹ã 2åå²ãããããªã°ã©ãã 2éšã°ã©ããšåŒãã§ãã. ãã®ãšã, n = 7ã§ãã 2éšã°ã©ããæã, ãã®ã°ã©ããå¥æ°æ¬ã®èŸºãããªãéè·¯ãå«ãŸãªãããšã瀺ã.(â»å®ã¯ã°ã©ãã«å¥æ°æ¬ã®èŸºãããªãéè·¯ãå«ãŸããªãããšã 2éšã°ã©ãã§ããããã®å¿ èŠååæ¡ä»¶ãšãªã£ãŠããã®ã§ããã, ãã®èšŒæã¯åŸã«è©³ããèŠãŠè¡ãããšã«ãã. ããã§ã¯, å ·äœçã«äžèšã®äºå®ã n = 7ã® 2éšã°ã©ãã«å¯ŸããŠç€ºãã ãã§ãã.)
(解çäŸ)
(1)æšã®æ§é ãæã€ãã®ã§ããã°äœã§ãè¯ãã, äŸãã°ããŒãã¡ã³ã圢åŒã®å¯ŸæŠã«ãŒãã®è¡šãªã©ã¯æšã§ãã.(2)äŸãã° n = 7ã®äºéšã°ã©ãã¯å³ 1.12ã®ããã«ãªã. åŸã£ãŠ, ãã®ã°ã©ãã®äžã«çŸããéè·¯ : 3 â 5 â
1 2 34
567
A group
B group
å³ 1.12: 7 åã®ç¹ãããªãäºéšã°ã©ãã®äŸ. å šãŠã®ç¹ã¯ group A ã group B ã®ããããã«æå±ã, ãäºãç°ãªãã°ã«ãŒãã«å±ããç¹ã©ãããã蟺ã§çµã°ãã. .
4 â 6 â 3 ãèŠããšç¢ºãã«å¶æ°æ¬ã®èŸºãããªã, å¥æ°æ¬ã®èŸºã§ã¯ãªã. äžè¬çã«èšã£ãŠ, äºéšã°ã©ãã¯ãã®å®çŸ©ãã, äžã€ã®ç¹ããåºçºã (ããã group Aãšããã), æ§ã ãªçµè·¯ãçµãŠèªåèªèº«ã«æ»ã£ãŠããããšãã§ã, éè·¯ãã§ãããšãããªãã°, å¿ ã A â B â · · · B â A ã®ãããªçµè·¯ããã©ãã¯ãã§ã
ã, åŸã£ãŠ, ãã®äžã«å«ãŸãã蟺ã®åæ° (ããã§æžãããšããã®âã®åæ°)ã¯å¿ ãå¶æ°æ¬ã§ãã, å¥æ°æ¬ã§ããããšã¯ããããªã.
ãã㯠14ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäžï¿œ
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ãäŸé¡ 1.4ã (2007幎床 æŒç¿åé¡ 1 )
(1)身ã®åãã§ãªã€ã©ãŒã»ã°ã©ã, ããã«ãã³ã»ã°ã©ãã®æ§è³ªãããŸã䜿ã£ãŠããå®äŸãããããæãã.
(2)ç¹éå V ãšèŸºéå E ããããã,
V = {v1, v2, v3, v4, v5}E = {v1v2, v2v3, v3v4, v4v5, v5v1, v1v3, v3v5, v5v2, v2v4, v4v1}
ã§äžããããã°ã©ãã®æŠåœ¢ãæã. ãŸã, ãã®ã°ã©ãã®æã€ç¹åŸŽãèå¯ã, ãããã®ãã¡ 2ã€ãæãã.
(解çäŸ)
(1)äŸãã°, å±ç€ºäŒã®äŒå Žãèšèšããå Žå, åããŒã¹ (ç¹ãšã¿ãªã)ã«åºãç©ããã, æ¥å Žè ã«åããŒã¹ã 2床以äžéããã«äŒå Žå ããŸãã, å ¥å£ããåºå£ (å ¥ãå£ãšå ±çš)ãžãšã¹ã ãŒãºã«ç§»åããŠãããããã«ã¯, ããã«ãã³ã»ã°ã©ããé©ããŠãã, ããã«ãã³ã»ã°ã©ãã®åé ç¹ã«åããŒã¹ã察å¿ãããããªäŒå Žãèšèšããã°è¯ã. äžæ¹, å±ç€ºç©ãåããŒã¹ã§ã¯ãªã, åéè·¯ã«å±ç€ºãããŠãããããªå Žå. äŸãã°, çŸè¡é€šãªã©ã«å±ç€ºãããŠããçµµç»ã¯é è·¯äžã«æ²ããããŠããå Žåãå€ãã, ãã®ãããªå Žåã«ã¯æ¥å®¢ãå ¥ãå£ããå šãŠã®éè·¯ã 1åã ãéã, äžçæžãã®é è·¯ã§åºå£ (å ¥ãå£ãšå ±çš)ãžãšæ»ããããã«äŒå ŽãèšèšããããšãæãŸãã. ãã®å Žåã«ã¯ãªã€ã©ãŒã»ã°ã©ããé©ããŠãã.ãŸã, éªåœã§ããæå¹åžç¹æã®åé¡ãšããŠãåžå ã®é€éªäœæ¥ãããã. ãã®å Žå, é€éªè»ã®å·¡åçµè·¯ã¯ãªã€ã©ãŒã»ã°ã©ãã§ããããšãæãŸãã. ã§ã¯å®é, æå¹åžå ã®éè·¯ããªã€ã©ãŒã»ã°ã©ããšã¿ãªããŠè¯ããåŠãã§ããã, åžå ã®äž»ãªéè·¯ã¯äº€å·®ç¹ã®åã ããå 14æ¡è¥¿ 9äžç®ãã®ããã«æå®ããããç¢ç€ã®ç®ãã®ããã«åºç»åãããŠããããšã«æ³šæãããš, åéè·¯ã®äº€å·®ç¹ã§ã®æ¬¡æ°ã¯ 4ã§ããããšãã (åžå ã®æå€éãç¡èŠãããéšåã°ã©ãããåãåºããš), åŸã«è©³ããã¿ããªã€ã©ãŒã®å®çãã, ãªã€ã©ãŒã»ã°ã©ããšã¿ãªãããšãã§ãã. åŸã£ãŠ, ãã®ãªã€ã©ãŒã»ã°ã©ãäžã®ãªã€ã©ãŒéè·¯ãé©åã«éžãã§é€éªè»ãå·¡åãããããšã§, æ¢ã«é€éªããé路㯠2床ãšéããªãã§æžããšããæå³ã§ã³ã¹ããåæžããããšãã§ãã. ãã£ãšã, åžå ã®äœå® è¡åšèŸºã®ããŒã«ã«ãªéè·¯ (é€éªäœæ¥ã«ãããŠã¯, ããæ¬è³ªçã§ãã)ã¯ç¢ç€ã®ç®ç¶ã§ã¯ãªã, (åœç¶å¥æ°æ¬¡ã®ç¹ãå«ã)ããè€éãªåœ¢ç¶ã§ãããã, ãã®ãããªããŒã«ã«ãªéè·¯ãå«ããå Žå, ãªã€ã©ãŒéè·¯ãååšããªãå Žåãããããšã«æ³šæããªããã°ãªããªã.
(2)åé¡ã®ç¹ã蟺éåãããªãã°ã©ããå®éã«æããŠã¿ããš 1.13ãšãªã. ãã®ã°ã©ã㯠(ç¹æ° 5ã®)å®å šã°
V1
V2
V3v4
v5
å³ 1.13: çãã®ã°ã©ã. å®å šã°ã©ããšåŒã°ãã.
ã©ããšåŒã°ã, äŸãã°æ¬¡ã®ãããªç¹åŸŽãæãã.
ãã㯠15ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
â¢å šãŠã®ç¹ã¯èªå以å€ã®å šãŠã®ç¹ãšçµã°ãã.
â¢åé¡ã®ã°ã©ã㯠10æ¬ã®èŸºãæãã. (äžè¬ã«èŸºã®æ°ã¯ç¹æ°ã nãšãããš nC2 = n(n â 1)/2æ¬ãã.)
â¢ãªã€ã©ãŒã»ã°ã©ãã§ãã, ããã«ãã³ã»ã°ã©ãã§ããã. ãã ã, ãªã€ã©ãŒã»ã°ã©ãã§ããã®ã¯ç¹ã®åæ°ãå¥æ°ã®ãšãã®ã¿. ä»ã®å Žåã¯ç¹æ° 5ãªã®ã§ãªã€ã©ãŒ.
ãã®å®å šã°ã©ãã¯ä»åŸé »åºããã®ã§èŠããŠãããšè¯ã.
ãã㯠16ããŒãžç®
17
第2åè¬çŸ©
2.1 å®çŸ©ãšäŸ
ãã®ç¯ã§ã¯ã°ã©ãçè«ã«çŸããæ°ã ã®å®çŸ©ãäŸã亀ããªãã解説ãã. éšåçã«ååè¬çŸ©ã§çŽ¹ä»ããäºé ããå«ãã, äŸãã°ãå圢ãã®å®çŸ©ãªã©, ããæ£ç¢ºãªèšè¿°ãããããåŠãã§è¡ãããšã«ãªã.
2.1.1 åçŽã°ã©ã
åçŽã°ã©ã : ã°ã©ãã«ã«ãŒããå«ãŸãã, é ç¹ã®ã©ã®å¯Ÿãé«ã 1ã€ã®ãªã³ã¯ã§çµã°ããŠããã°ã©ã.
V (G) : ã°ã©ã Gã®ç¹éå (vertex set)
E(G) : ã°ã©ã Gã®èŸºéå (edge set)
ÏG : ã°ã©ã Gã®æ¥ç¶é¢æ° (incidence function)ã
ã©ã®ã°ã©ã (åçŽã°ã©ããå«ã)Gã V (G)ãš E(G)ãããªã.é£ããèšããš âãã°ã©ãG㯠V (G)ãš V (G)ã®å ã®éé åºå¯Ÿãããªãæéãªæ (è€æ°åã®åãå ããã£ãŠããã) ã§ãã E(G)ãããªã.ã
å³ 2.14ã«åçŽã°ã©ããšãã®ç¹éååã³èŸºéåãèŒãã. ååºã®ã°ã©ã Gã®æ¥ç¶é¢æ°ãšã¯ Gã®å蟺㫠Gã®é ç¹ã®å¯Ÿã察å¿ãããé¢æ°ã§ãã, ãã®å³ã®äŸã§ãããš
ÏG(e1) = uv, ÏG(e2) = vw
ÏG(e3) = wu, ÏG(e4) = wz
ã®ããã«ãªã.
u
vw
z
V(G)={u,v,w,z}
E(G)={uv,vw,vw,wz}
e1
e2
e3e4
å³ 2.14: åçŽã°ã©ã G ã®äŸãšç¹éå V (G) åã³èŸºéå E(G).
äžæ¹, å³ 2.15 ã«äžè¬ã°ã©ã (general graph) ( ã«ãŒããå€é蟺ããèš±ãããã°ã©ã)ã®äžäŸãèŒãã.ãã®å³ã«ãããŠå蟺ã®çŸããåæ°ã¯ uv(1å), vv(ã«ãŒã, 2å), vw(3å), uw(2å), wz(1å)ã§ãã.
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
u
v w
z
å³ 2.15: äžè¬ã°ã©ã G ã®äžäŸ.
2.1.2 å圢
2ã€ã®ã°ã©ã G1ãšG2ã®éã«äžå¯Ÿäžã®å¯Ÿå¿é¢ä¿ããã, G1ã®ä»»æã® 2ç¹ãçµã¶èŸºæ°ãG2 ã®å¯Ÿå¿ãã 2ç¹ãçµã¶èŸºæ°ã«çãããšã, G1ãšG2ã¯å圢 (isomorphic)ã§ãããšãã. å³ 2.16 ã® 2ã€ã®ã°ã©ã G1å
u v w
x y z
l (u) p (x)
r (z)
n (w) g (y)
m (v)
G1
G2
å³ 2.16: å圢ã°ã©ã G1 ãš G2.
ã³ G2ã¯å圢ã§ãã, G2 äžã«æžã蟌ãã ãããªå¯Ÿå¿é¢ä¿ãæã€.
(è£è¶³äºé )å ã«å®çŸ©ããæ¥ç¶é¢æ°ãçšãããš, 2ã€ã®ã°ã©ã G1,G2 ãå圢ã§ãããšã, 1察 1åå :
Ξ : V (G1) â V (G2)
Ï : E(G1) â E(G2)
ã次ã®é¢ä¿ :
ÏG1(e) = uv â ÏG2(Ï(e)) = Ξ(u)Ξ(v)
ãæãç«ã€. ãã®ãããªååã®å¯Ÿ (Ï, Ξ)ãG1,G2éã®å圢ååãšåŒã³,ãã®å圢ååãååšããå Žå, G1,G2
ã¯å圢ã§ãããšèšã, åŒã§ã¯ G1âŒ= G2 ãšè¡šçŸãã.
ãããå®éã«å³ 2.16ã®G1,G2ã§ç¢ºããããš
Ξ(u) = l, Ξ(v) = m, Ξ(w) = n
Ξ(x) = p, Ξ(y) = q, Ξ(z) = r
åã³
Ï(ux) = lp = Ξ(u)Ξ(x)
ãã㯠18ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
Ï(uz) = lr = Ξ(u)Ξ(z)
· · · · · · · · ·
ãšãªããã
ÏG1(ux) = ux â ÏG2(Ï(ux)) = ÏG2(lp) = lp = Ξ(u)Ξ(x)
çã®æç«ã確ãããã, åŸã£ãŠ, å³ 2.16ã® G1,G2 ã¯å圢ã§ããããšãããã (ãã¡ãã, ãã®å Žåã®ååÏ, Ξã¯å圢ååã§ãã).
2.1.3 ã©ãã«ä»ãã°ã©ããšã©ãã«ãªãã°ã©ã
åç¹ã«ååã®ä»ãããã°ã©ããã©ãã«ä»ãã°ã©ããšåŒã¶. ååã®è¬çŸ©ã§ã¿ãäŸé¡ 1.1ã§æ±ã£ãççŽ ååã䞊ã¹ãæšã«é¢ããŠã, ãã®èª²é¡ã§ã¯ãã©ãã«ãªãããšããŠãã®å Žåãæ°ããã, ã©ãã«ä»ãã®æšãšããŠæ±ãéã«ã¯å³ã® 2ã€ã®æšã¯å¥åã®æšãšããŠæ±ãããšã«ãªã.
1 2 3 4
5
1 2 3 4
5
å³ 2.17: äŸé¡ 1 ã§æ±ã£ãççŽ ååã®æšãã©ãã«ä»ãã§èãããšäž¡è ã¯ç°ãªãæšãšã¿ãªããã.
2.1.4 é£çµã°ã©ã
é£çµã°ã©ããšã¯å¹³ããèšãã°ãäžã€ã«ã€ãªãã£ãŠããã°ã©ãããšããããšã«ãªãã, ç¹å士ããé£çµããããé£çµãããããšããæŠå¿µãçšãããš, äžèšã®ããã«, ããå°ãäžå¯§ã«é£çµã°ã©ããå®çŸ©ããããšãã§ãã.
ãŸã, ã°ã©ã Gã®ç¹ u, vã«é¢ããŠ, Gã« u, vãçµã¶éãããã°, u㯠vã«é£çµããããšèšã.
ããã§, ã°ã©ã Gãæ§æããä»»æã® 2ç¹ u, vã«å¯Ÿã,
u㯠vã«é£çµããã â u㯠vãšåã Vi ã«å±ãã
ãšããããã«ã°ã©ãGãGã®ç¹ãããªã空ã§ãªãéšåéå V1, V2, · · · , Vi, · · · , Vn ã§åå²ãããšã, åéåãããªãéšåã°ã©ã G(V1),G(V2), · · · ,G(Vn) ãããããã°ã©ã Gã®æå (component) ãšåŒã³, æåã1ã€ã ãã®ã°ã©ããé£çµã°ã©ã (connected graph)ãšå®çŸ©ãã. å³ 2.18ã«é£çµã°ã©ã (G1) åã³, æåæ°ã 3ã§ããéé£çµã°ã©ã (G2) ã®äŸãèŒãã. èšããŸã§ããªãããšã ã, éé£çµã°ã©ã (disconnected
graph)ãšã¯é£çµã°ã©ãã§ãªãã°ã©ãã®ããšã§ãã.
2.1.5 次æ°ããã³æ¬¡æ°å
ã°ã©ã Gåã³ãã®äžã®ç¹ vã«é¢ãã, 次ã«ãããéèŠãªæŠå¿µãæŒãããŠããã.
â¢ ç¹ vã®æ¬¡æ° (degree)vã«æ¥ç¶ããŠãã蟺ã®æ¬æ°. ãã ã, ã«ãŒãã®å Žå㯠2æ¬ãšã«ãŠã³ããã. åŒã§æžããš deg(v)ãšãªã.
ãã㯠19ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
G G1 2
å³ 2.18: é£çµã°ã©ã G1 ãšéé£çµã°ã©ã G2. G2 ã®æåæ°ã¯ 3 ã§ãã.
⢠å€ç«ç¹ (isolated vertex)次æ°ãŒãã®ç¹
â¢ ç«¯ç¹ (end-vertex)
æ¬¡æ° 1ã®ç¹
⢠ã°ã©ã Gã®æ¬¡æ°å (degree sequence)
次æ°ãå¢å é ã«èšãããã®. å¿ èŠãšãªãã°åã次æ°ãç¹°ãè¿ããŠãè¯ã. å³ 2.18ã®G1ã®äŸã§èšããš,ãã®é£çµã°ã©ãã®æ¬¡æ°å㯠(1, 1, 1, 3, 3, 4, 5).
ãŸã, ã°ã©ãã®æ¬¡æ°ã«é¢ããŠæ¬¡ã®æåãªè£é¡ãç¥ãããŠãã.
æ¡æè£é¡ (handshaking lemma) : ä»»æã®ã°ã©ãã®å šãŠã®ç¹ã®æ¬¡æ°ãåèšããã°å¿ ãå¶æ°ã«ãªã.
ãŸã, æŽæ°å d1, d2, · · · , dn ãäžãããããšã, nåã®ç¹ãããªãã°ã©ã Gã«å¯Ÿã, å iã«é¢ããŠ
deg(vi) = di (2.2)
ãæç«ãããšã, æ°å d1, d2, · · · , dn ã¯ã°ã©ãçã§ãããšãã. äŸãã°, æ°å (4, 3, 2, 2, 1)ã¯ã°ã©ãçã§ãã,
v1
v2
v4
v3
v5
å³ 2.19: ãã°ã©ãçãã§ããã°ã©ãã®äžäŸ.
ãã®ã°ã©ãã¯å³ 2.19ã§ãã. 察å¿é¢ä¿ã¯
d(v1) = 4, d(v2) = 3, d(v3) = 2, d(v4) = 2, d(v5) = 1 (2.3)
ãšãªã.
2.1.6 éšåã°ã©ã
ã°ã©ã Gã®éšåã°ã©ã (subgraph) : ç¹ãå šãŠ V (G)ã«å±ã, ãã®èŸºãå šãŠ E(G)ã«å±ããã°ã©ã.
ãã㯠20ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
åŸã£ãŠ, ãããªãå Žåã«ã, ã°ã©ãGã®ç¹ãšèŸºã®é€å», åã³èŸºã®çž®çŽ (蟺ãé€å»ã, ãã®èŸºã®äž¡ç«¯ã«ã€ããŠãã 2ç¹ãåäžèŠã㊠1ç¹ã«ããããš)ãšããæäœãè¡ãããšã«ãã, ã°ã©ã Gã®éšåã°ã©ããäœãããšãã§ãã.
2.1.7 è¡åã«ããã°ã©ãã®è¡šçŸæ¹æ³
ã°ã©ããèšç®æ©äžã§è¡šçŸããå Žåã«ã¯åã ã®ã°ã©ãã®ç¹åŸŽãæ°éåã, ãã®æ°åãçšããŠã³ãŒãã£ã³ã°ããå¿ èŠããã. ãã®ãšã, äžèšã«æããé£æ¥è¡ååã³, æ¥ç¶è¡åãšããè¡åã«ããè¡šçŸæ¹æ³ã䟿å©ã§ãã.
ã°ã©ã Gã®ç¹åã³èŸºã 1, 2, · · · , n, 1, 2, · · · ,mãšããããã©ãã«ä»ããããŠãããšãããš
é£æ¥è¡å (adjacency matrix) : ç¹ iãšç¹ j ãçµã¶èŸºã®æ¬æ°ã第 ij èŠçŽ ãšãã nà nã®è¡åæ¥ç¶è¡å (incidence matrix) : ç¹ iã蟺 j ã«æ¥ç¶ããŠããå Žå, 第 ij èŠçŽ ã 1ã§ãã, æ¥ç¶ããŠããªãå Žå 0 ã§ãããã㪠nÃmã®è¡å5ï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 2.1ã (2003幎床 ã¬ããŒãèª²é¡ #1 åé¡ 1 )
å³ã«äžããããã°ã©ãã«ã€ããŠä»¥äžã®åãã«çãã.
1
23
12
3
4
56
(1)ãã®ã°ã©ãã®æ¬¡æ°åãæžã.(2)å³ã®ã°ã©ãã«å¯ŸããŠé£æ¥è¡åAåã³æ¥ç¶è¡åM ãæ±ãã.
(解çäŸ)
(1)次æ°å㯠(3, 3, 3, 3).(2)ããããã®å®çŸ©ã«åŸãã°é£æ¥è¡åAã¯
A =
ââââââ
0 1 1 11 0 1 11 1 0 11 1 1 0
ââââââ (2.4)
æ¥ç¶è¡åM ã¯
M =
ââââââ
1 1 0 1 0 00 1 1 0 1 01 0 1 0 0 10 0 0 1 1 1
ââââââ (2.5)
5 ç¹ v ã«ãããŠèŸº e ããã«ãŒãããšããŠæ¥ç¶ããŠããå Žå, ãã®ã°ã©ãã®æ¥ç¶è¡åã®ç¬¬ ve æåã, æç§æžã«ãã£ãŠã¯ 1 ãšå®çŸ©ããŠãããã®ãš 2 ãšå®çŸ©ããŠãã 2 éããããããã§ããã, ãã®è¬çŸ©ã§ã¯ãã®å Žå 1 ãšããŠæ¥ç¶è¡åãå®çŸ©ãã. åŸã£ãŠ, æ¥ç¶è¡åã®æåã¯å¿ ã 0 ã 1 ã§ãã.
ãã㯠21ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãšãªã.ï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 2.2ã (2004幎床 æŒç¿åé¡ 2 )
以äžã®åé¡ã«çãã.
1. å³ã®G1 ãš G2ã®éã®å圢åå Ï, ΞãèŠã€ãã.a
b
c d
e
1
2
3
4
5
G G1 2
ãŸã, G1 ã®ä»»æã®èŸº eåã³ç¹ u, vã«å¯ŸããŠ
ÏG1(e) = uv â ÏG2(Ï(e)) = Ξ(u)Ξ(v)
ãæãç«ã£ãŠããããšã 2,3ã® {e, u, v}ã®çµã«å¯ŸããŠç¢ºããã.2. å³ 2.16ã®ã°ã©ã G2ã®éšåã°ã©ãã 2ã€æãã.3. 次ã®é£æ¥è¡åA, æ¥ç¶è¡åM ã§äžããããã°ã©ããããããæã.
A =
ââââââââ
0 1 1 2 01 0 0 0 11 0 0 1 12 0 1 0 00 1 1 0 0
ââââââââ , M =
ââââââââ
0 0 1 1 1 1 1 00 1 0 1 0 0 0 10 0 0 0 0 0 0 11 0 1 0 1 0 1 01 1 0 0 0 1 0 0
ââââââââ
(解çäŸ)
1. æ±ããå圢åå Ξ, Ïã¯ã°ã©ã G1,G2 ã®åç¹ã«å¯ŸããŠ
Ξ(a) = 1, Ξ(b) = 2, Ξ(c) = 3, Ξ(d) = 4, Ξ(e) = 5
å蟺ã«å¯ŸããŠ
Ï(ab) = 12, Ï(bc) = 23, Ï(cd) = 34, Ï(bd) = 24
Ï(de) = 45, Ï(ce) = 35, Ï(ea) = 51
åŸã£ãŠ, ãã®ååã®äžã§
ÏG1(ab) = ab â ÏG2(Ï(ab)) = ÏG2(12) = Ξ(a)Ξ(b)
ÏG1(bc) = bc â ÏG2(Ï(bc)) = ÏG2(23) = Ξ(b)Ξ(c)
ÏG1(cd) = cd â ÏG2(Ï(cd)) = ÏG2(34) = Ξ(c)Ξ(d)
ÏG1(de) = de â ÏG2(Ï(de)) = ÏG2(45) = Ξ(d)Ξ(e)
ÏG1(ea) = ea â ÏG2(Ï(ea)) = ÏG2(51) = Ξ(e)Ξ(a)
ÏG1(ce) = ce â ÏG2(Ï(ce)) = ÏG2(35) = Ξ(c)Ξ(e)
ÏG1(bd) = bd â ÏG2(Ï(bd)) = ÏG2(24) = Ξ(b)Ξ(d)
ãæãç«ã€.
ãã㯠22ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
l p
r
n
p
m
å³ 2.20: ã°ã©ã G2 ã®éšåã°ã©ãã®äŸ.
2. äŸãã°å³ 2.20 ã®ãããªã°ã©ãã G2ã®éšåã°ã©ãã§ãã.3. ãŸã, é£æ¥è¡å A ã«ã€ããŠèãã. ãã®é£æ¥è¡åã®ãµã€ãºãã, æ±ããã°ã©ãã®ç¹ã®æ°ã¯ n = 5ã§ãã, é£æ¥è¡åã¯å¿ ã察称è¡åã§ããããšã«æ³šæããã. ãŸã, ãã®è¡åAã®å¯Ÿè§æåã¯å šãŠãŒãã§ãã
ããšãã, ãã®ã°ã©ãã«ã¯ã«ãŒããå«ãŸããªãããšãçŽã¡ã«ããã. 以äžã«æ³šæããªããé£æ¥è¡åã®å®çŸ©ã«åŸã£ãŠã°ã©ããæããšå³ 2.21ã®ããã«ãªã. ãã¡ãã, ãã®å³ãšå šãåãã§ãªããŠã, å圢ãªã°ã©
b a
e c
d
å³ 2.21: é£æ¥è¡åã A ã§äžããããã°ã©ã. ããã§, é£æ¥è¡å A ã®ç¬¬ 1 è¡, 2 è¡,ã»ã»ã»ã®çªå·ãšããŠ, å³ã®ç¹ a,b,ã»ã»ã»ã察å¿ããŠããããšã«æ³šæ.
ããªãã°æ£è§£ã§ãã.
次ã¯æ¥ç¶è¡åM ãæã€ã°ã©ãã«é¢ããŠã§ããã, 以äžã®ç¹ã«æ³šæããªããèå¯ãããšã°ã©ããæãããã.
â¢é£æ¥è¡åã®ååã«ã¯å¿ ã 2åã® 1ããã, 察å¿ããè¡ã®çªå·ãä»ãããç¹å士ãçµã°ã, ããã«ããåºæ¥äžãã蟺ã«ã¯ãã®åã®çªå·ãå²ãåœãŠããã.
â¢ç¬¬ iè¡, 第 j è¡ã« 1ãç«ã£ãŠããåã læ¬ããå Žå, ç¹ i, jéã«ã¯ léã®å€é蟺ãååšãã.
以äžã«æ³šæããªããã°ã©ããæããšå³ 2.22ã®ããã«ãªã.
e b
a
d
c2
64
8
17
3
5
å³ 2.22: é£æ¥è¡åãMã§äžããããã°ã©ã. ããã§, æ¥ç¶è¡åM ã®ç¬¬ 1 å, 2 åã»ã»ã»ã®çªå·ãšããŠ, å³ã® a,b,ã»ã»ã»ã察å¿ããŠããããšã«æ³šæ.
ãã㯠23ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäžï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 2.3ã (2005幎床 æŒç¿åé¡ 2 )
以äžã®åãã«çãã.
(1) 5åã®ç¹ãš 8æ¬ã®èŸºããã€æ¬¡ã®ãããªã°ã©ããæã.(i) åçŽã°ã©ã(ii) ã«ãŒãããªã, åçŽã§ãªãã°ã©ã(iii) å€é蟺ããªã, åçŽã§ãªãã°ã©ã
(2)å³ã«äžããããã°ã©ãã®é£æ¥è¡åA, æ¥ç¶è¡åM ãæ±ãã.
1
2 34
5
12
3
4 5
6
(3) 6ç¹ãããªãã°ã©ãã§, åç¹ã®æ¬¡æ°åã (3, 3, 5, 5, 5, 5)ã§ãããã®ãæã. ãã®æ¬¡æ°ããã€åçŽã°ã©ãã¯ååšããã ?
(解çäŸ)
1. (i)(ii)(iii)ãæºããã°ã©ãã¯å³ 2.23ã®ããã«ãªã.
1
2
3
4
56 7
8
1
2
3
4
5 6
7
8
1
2
3
4
5 6
7
8
(i) (ii) (iii)
å³ 2.23: 5 åã®ç¹ãš 8 æ¬ã®èŸºããã€ã°ã©ãã§æ¡ä»¶ (i)(ii)(iii) ãæºãããã®.
2. å®çŸ©ã«åŸãã°, é£æ¥è¡åA, æ¥ç¶è¡åM ã¯
A =
ââââââââ
0 1 1 1 01 0 1 0 01 1 0 1 11 0 1 0 00 0 1 0 0
ââââââââ , M =
ââââââââ
1 1 1 0 0 01 0 0 1 0 00 1 0 1 1 10 0 1 0 1 00 0 0 0 0 1
ââââââââ
(2.6)
3. å³ 2.24ãåç §. åçŽã°ã©ãã¯ç¡ã.
ãã㯠24ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
1(3) 2(3)
3(5)
4(5)
5(5)
6(5)
å³ 2.24: 6 ç¹ãããªãã°ã©ãã§æ¬¡æ°å (3, 3, 5, 5, 5, 5) ã§ãããã®.
ᅵ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 2.4ã (2006幎床 æŒç¿åé¡ 2 )
以äžã®åãã«çãã.
(1)è¬çŸ©ããŒã#1ã®äŸé¡ 1.3 (2) ã®è§£çã«èŒããå³ã®äºéšã°ã©ãã®é£æ¥è¡åãšæ¥ç¶è¡å, åã³æ¬¡æ°åãããããæ±ãã. ãã ã, æ¥ç¶è¡åãæ±ããéã«ã¯, åèªãã©ã®ããã«å蟺ã«çªå·ããµã£ãã®ããæ瀺ããŠè§£çãäœæããããš.
(2)次æ°å (3, 3, 3, 3, 3, 3)ã¯ã°ã©ãçã ? çç±ãšãšãã«çãã.(3)äŸé¡ 2.2ã® 1. ã«ãªãã£ãŠå³ 2.25ã«èŒãã 2ã€ã®ã°ã©ã G1,G2 ã®å圢åå Ξ, ÏãèŠã€ã, G1
ã®ä»»æã®èŸº eåã³ç¹ u, vã«å¯ŸããŠ
ÏG1(e) = uv â ÏG2(Ï(e)) = Ξ(u)Ξ(v)
ãæãç«ã£ãŠããããšã {e, u, v}ã®çµã«å¯ŸããŠç¢ºããã.
(解çäŸ)
a b
cd
G1
1
23
4
G2
å³ 2.25: ããã§ãã®å圢æ§ãè°è«ããã°ã©ã G1, G2.
(1)åé¡ã®äºéšã°ã©ãã®é£æ¥è¡åAã¯
A =
âââââââââââââ
0 0 0 0 0 1 10 0 0 0 0 0 10 0 0 0 1 1 00 0 0 0 1 1 00 0 1 1 0 0 01 0 1 1 0 0 01 1 0 0 0 0 0
âââââââââââââ
(2.7)
ãã㯠25ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãšãªã. ãŸã, å³ 2.26ã®ããã«å蟺ã«çªå·ãæ¯ããš, ãã®ã°ã©ãã®æ¥ç¶è¡åM ã¯
M =
âââââââââââââ
1 1 0 0 0 0 00 0 1 0 0 0 00 0 0 1 0 1 00 0 0 0 1 0 10 0 0 0 0 1 10 1 0 1 1 0 01 0 1 0 0 0 0
âââââââââââââ
(2.8)
ãšæžãã.
1 2 34
567
A group
B group
12
3
4
5
6 7
å³ 2.26: å³ã®ããã«å蟺ã«çªå·ãæ¯ã£ãŠæ¥ç¶è¡åãæ±ãã.
(2)å³ 2.27ã«æããå®å šäºéšã°ã©ãK3,3ã®æ¬¡æ°å㯠(3, 3, 3, 3, 3, 3)ã§ãããã, ãã®æ¬¡æ°å (3, 3, 3, 3, 3, 3)ã¯ãã°ã©ãçãã§ãã.â» å®å šäºéšã°ã©ãK3,3 ã®æãæ¹ã¯è§£çäŸä»¥å€ã«ãæ§ã èãããã. ãã®è§£çäŸãšå圢ãªã°ã©ãã§ããã°æ£è§£.
å³ 2.27: å³ã®å®å šäºéšã°ã©ãã®æ¬¡æ°å㯠(3, 3, 3, 3, 3, 3) ã§ãã.
(3)åå Ξ, Ïã
Ξ(a) = 1, Ξ(b) = 2, Ξ(c) = 3, Ξ(d) = 4 (2.9)
Ï(ab) = 12, Ï(ac) = 13, Ï(ad) = 14, Ï(bd) = 24, Ï(cd) = 34, Ï(bc) = 23 (2.10)
ãšããã°, æ¥ç¶é¢æ° ÏG1 , ÏG2 ã«å¯ŸããŠ
ÏG1(ab) = ab â ÏG2(Ï(ab)) = ÏG2(12) = 12 = Ξ(a)Ξ(b) (2.11)
ÏG1(ac) = ac â ÏG2(Ï(ac)) = ÏG2(13) = 13 = Ξ(a)Ξ(c) (2.12)
ÏG1(ad) = ad â ÏG2(Ï(ad)) = ÏG2(14) = 14 = Ξ(a)Ξ(d) (2.13)
ÏG1(bd) = bd â ÏG2(Ï(bd)) = ÏG2(24) = 24 = Ξ(b)Ξ(d) (2.14)
ãã㯠26ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ÏG1(cd) = cd â ÏG2(Ï(cd)) = ÏG2(34) = 34 = Ξ(c)Ξ(d) (2.15)
ÏG1(bc) = bc â ÏG2(Ï(bc)) = ÏG2(23) = 23 = Ξ(b)Ξ(c) (2.16)
ãæãç«ã€. åŸã£ãŠ, ã°ã©ã G1, G2ã¯å圢ã§ãã.
以äžã®äžé£ã®äŸé¡ãšãã®è§£çäŸã§ã¯é£çµã°ã©ããå°äžéã®è·¯ç·å³ã«èŠç«ãŠãå Žåã®äº€éé, ä¹å®¢ã®æµãçãã°ã©ãçè«ãçšããŠèå¯ããæ¹æ³ãäŸé¡åœ¢åŒã§èŠãŠãã. ãã¡ãã, ããã§åãäžããã°ã©ãã§è©±ãæžããããª, ãããªåçŽãªå°äžéè·¯ç·ã¯æ±äº¬ã«ããã³ãã³ã«ããªã (æå¹ã®å°äžéã¯ããªãã·ã³ãã«ã ã, ã»ãšãã©éè·¯ãå«ãŸãªããæšãã§ããããã«æããã), ãã®æå³ã§çŸå®ã®åé¡ãšã¯çšé ãã, ããã§åŠã¶æ¹æ³ã»æŠå¿µã, ãã倧ããªãµã€ãºã®è€éãªã°ã©ããžãšå¿çšããããšã§å®éã®å°äžéè·¯ç·ã®åé¡ãæ±ãããšã¯,ãµã€ãºå¢å ã«ãšããªãèšç®æè¡äžã®åé¡ãã¯ãªã¢ãããããã°, ãã€ã§ãå¯èœã§ããããšã«æ³šæãããã.äžèšã®äŸé¡ 2.5-aããäŸé¡ 2.5-fã¯æã ãæçµçã«èª¿ã¹ããäŸé¡ 2.5-gãžåããŠã®èªå°ãšãªã£ãŠãã.ï¿œ
ᅵ
ᅵ
ᅵ
ããäŸé¡ 2.5-a ã (2004幎床æ å ±å·¥åŠæŒç¿ II(B) #2)
ã°ã©ã Gã®ä»»æã® 2ç¹ u, véã®è·é¢ã d(u, v)ãšãã. ä», ç¹ uãåºå®ã, v (ï¿œ= u) ãä»»æã® Gå ã®ç¹
ãšãããšã, d(u, v)ã®æ倧å€ãç¹ uããã®æé è·é¢ãšå®çŸ©ã, e(u)ãšæžãããšã«ãã. ãŸã, Gå ã®å š
ãŠã®ç¹ uã«å¯Ÿãã e(u)ã®æå°å€ãã°ã©ã Gã®ååŸãšåŒã³, R(G)ãšæžã. ããã«, å šãŠã® uã«å¯Ÿãã
e(u)ã®æ倧å€ã Gã®çŽåŸãšåŒã³, D(G)ãšæžã. ãŸã, ååŸã«çããæçè·é¢ãæã€ç¹ã®éåã Gã®äž
å¿ãšåŒã³, æé è·é¢ãæã€ç¹ã®éåã Gã®åšèŸºãšèšã. äŸãã°å³ 2.28(å·Š)ã®ã°ã©ã GãäŸã«ãšãã°å
ç¹ã®æé è·é¢ã¯ e(1) = 2, e(2) = 2, e(3) = 2, e(4) = 2, e(5) = 2 ã§ãã, R(G) = 2, D(G) = 2, äžå¿ã¯{1, 2, 3, 4, 5}, åšèŸºã¯ {1, 2, 3, 4, 5}ã§ãã.ãããåèã«ããŠå³ 2.28(å³)ã®ã°ã©ãã®åç¹ã®æé è·é¢, ååŸ, çŽåŸ, äžå¿, åã³, åšèŸºãæ±ãã.
1
2
3
4
5
G1
2
3
4
5
6
G
å³ 2.28: ã°ã©ã G(å·Š) ã®åç¹ã®æé è·é¢ã¯ e(1) = 2, e(2) = 2, e(3) = 2, e(4) = 2, e(5) = 2 ã§ãã, R(G) = 2, D(G) = 2, äžå¿ã¯ {1, 2, 3, 4, 5}, åšèŸºã¯ {1, 2, 3, 4, 5} ã§ãã. å³ãããã§èããé£çµã°ã©ã G(å°äžéè·¯ç·å³).
(解çäŸ)
ãŸã, u, véã®è·é¢ d(u, v)ãšã¯ç¹ uããç¹ vãžè³ãçµè·¯ã®äžã§ã®æçè·¯ã§ããããšã«æ³šæãã. ãããš,åé¡ã®å³ 2.28(å³)ã®ç¹ 1ãåºç¹ãšããéã®åä»ç¹ãžã®è·é¢ã¯
d(1, 2) = 2, d(1, 3) = 2, d(1, 4) = 3, d(1.5) = 2, d(1, 6) = 1 (2.17)
ãã㯠27ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ã§ãããã, ç¹ 1ã«é¢ããæé è·é¢ e(1)ã¯
e(1) = maxy ᅵ=1
d(1, y) = 3 (2.18)
ãšãªã. 2, · · · , 6ãåºç¹ãšããå Žåã (2.17)(2.18)ãšåæ§ã«ããŠé 次, æé è·é¢ãæ±ããŠãããš
d(2, 1) = 1, d(2, 3) = 1, d(2, 4) = 2, d(2, 5) = 1, d(2, 6) = 1, e(2) = maxy ᅵ=2
d(2, y) = 2
d(3, 1) = 2, d(3, 2) = 1, d(3, 4) = 1, d(3, 5) = 1, d(3, 6) = 2, e(3) = maxy ᅵ=3
d(3, y) = 2
d(4, 1) = 3, d(4, 2) = 2, d(4, 3) = 1, d(4, 5) = 1, d(4, 6) = 2, e(4) = maxy ᅵ=4
d(4, y) = 3
d(5, 1) = 2, d(5, 2) = 1, d(5, 3) = 1, d(5, 4) = 1, d(5, 6) = 1, e(5) = maxy ᅵ=5
d(5, y) = 2
d(6, 1) = 1, d(6, 2) = 1, d(6, 3) = 2, d(6, 4) = 2, d(6, 5) = 1, e(6) = maxy ᅵ=6
d(6, y) = 2
以äžã®çµæãã, åé¡æäž, å³ 2.28 (å³) ã®ã°ã©ã Gã®ååŸ R(G), åã³, çŽåŸD(G)ã¯
R(G) â¡ minx
e(x) = 2 (2.19)
D(G) â¡ maxx
e(x) = 3 (2.20)
ãšãªã. ãŸã, äžå¿ã¯ {2, 3, 4, 5}, åšèŸºã¯ {1, 4}ã§ãã.
ᅵ
ᅵ
ᅵ
ᅵ
ããäŸé¡ 2.5-b ã (2004幎床æ å ±å·¥åŠæŒç¿ II(B) #2)
Aãã°ã©ã Gã®é£æ¥è¡åãšãããšã, 次ã®å :
S(r) = A + A2 + A3 + · · ·+ Ar =râ
k=1
Ak (2.21)
ã®èŠçŽ [S(r)]ij ã¯ç¹ iããç¹ j ã«è³ãé·ã r以äžã®æ©éã®ç·æ°ã§ããããšãå³ 2.28(å³)ã®ã°ã©ã Gã®
äŸãçšããŠç€ºã. ãŸã, (2.21)åŒã§ rã®å€ã 1ããåŸã ã«å¢ãããŠãã£ããšã, S(r)ã®é察è§èŠçŽ ãå šãŠéãŒãã«ãªã£ããšãã® rã®å€ã¯, äŸé¡ 2.5-aã§è¿°ã¹ãçŽåŸD(G)ã«ãªã£ãŠããããšãå³ 2.28(å³)ã®Gã«å¯ŸããŠç€ºã.
(解çäŸ)
ãŸã, ã°ã©ã Gã®é£æ¥è¡åAã¯
A =
âââââââââââ
0 1 0 0 0 11 0 1 0 1 10 1 0 1 1 00 0 1 0 1 00 1 1 1 0 11 1 0 0 1 0
âââââââââââ
(2.22)
ãã㯠28ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ã§ãã. åŸã£ãŠ, ããéå±ã§ã¯ããã, ãã®é£æ¥è¡åã«é¢ããŠA2,A3ãé次èšç®ããŠã¿ããš
A2 =
âââââââââââ
2 1 1 0 2 11 4 1 2 2 21 1 3 1 2 20 2 1 2 1 12 2 2 1 4 11 2 2 1 1 3
âââââââââââ , A3 =
âââââââââââ
2 6 3 3 3 56 6 8 3 9 73 8 4 5 7 43 3 5 2 6 33 9 7 6 6 85 7 4 3 8 4
âââââââââââ
(2.23)
ãšãªã (Aã察称è¡åã§ãããã, A2,A3 ã察称è¡åã§ããããšã«æ³šæ). ãã£ãŠ, S(1),S(2),S(3)ã¯é 次ã«
S(1) = A =
âââââââââââ
0 1 0 0 0 11 0 1 0 1 10 1 0 1 1 00 0 1 0 1 00 1 1 1 0 11 1 0 0 1 0
âââââââââââ
(2.24)
S(2) = A + A2 =
âââââââââââ
2 2 1 0 2 32 4 2 2 3 31 2 3 2 3 20 2 2 2 2 12 3 3 2 4 22 3 2 1 2 3
âââââââââââ
(2.25)
S(3) = A + A2 + A3 =
âââââââââââ
4 8 4 3 5 88 10 10 5 12 104 10 7 7 10 63 5 7 4 8 45 12 10 8 10 107 10 6 4 10 7
âââââââââââ
(2.26)
ãšãªã, r = 3ã§åããŠ, S(r)ã¯èŠçŽ ãå šãŠéãŒããšãªã. åŸã£ãŠ, ãã® r = 3ã¯äŸé¡ 2.5-aã§æ±ããçŽåŸ
D(G)ã«çããããšãããã.
ãã㯠29ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäžï¿œ
ᅵ
ᅵ
ᅵ
ããäŸé¡ 2.5-cã (2004幎床æ å ±å·¥åŠæŒç¿ II(B) #2)
äŸé¡ 2.5-bã§ã® S(r)ã®ä»£ããã«, ηã η ⥠1ã®å®æ°ãšããŠ
W (r) =A
η+(
A
η
)2
+(
A
η
)3
+ · · ·+(
A
η
)r
=râ
k=1
(A
η
)k
(2.27)
ãèãã. äŸãã°, ããã¯å³ 2.28(å³)ã®ã°ã©ã Gãå°äžéã®è·¯ç·å³ã§ãããšãããªãã°, ãè¿ãé§ éã»ã©ä¹å®¢ã®å©çšé »åºŠ (䟡å€)ãé«ãããªã©ã®ããã«çŸå®ã®åé¡ãšé¢é£ãã, æå³ã¥ãããããšãã§ãã. ããŠ, ãã®è¡åW (r)ã«å¯Ÿã
Cr(i, r) = [W (r)]1i + [W (r)]2i + · · ·+ [W (r)]ni =nâ
j=1
[W (r)]ji (2.28)
ãç¹ iã«ãããé·ã rã®ã¿ãŒããã«å®¹éãšåŒã¶. å³ 2.28(å³)ã®ã°ã©ã Gã®åç¹ã«å¯ŸããŠé·ã 2ã®ã¿ãŒããã«å®¹éãæ±ãã. ãã ã, η = 6ãšãã. ãŸã, å³ 2.28(å³)ã®ã°ã©ããå°äžéã®è·¯ç·å³ãšèããå Žå, ããã§åŸãããçµæã¯äœãæå³ããã, ãç°¡æœã«è¿°ã¹ã.
(解çäŸ)
åé¡æã®å®çŸ©ã«åŸã£ãŠ, W (2)ãæ±ããŠã¿ã. η = 6ã§ããããçŽã¡ã«
W (2) =1η
A +1η2
A2
=136
âââââââââââ
0 6 0 0 0 66 0 6 0 6 60 6 0 6 6 00 0 6 0 6 00 6 6 6 0 66 6 0 0 6 0
âââââââââââ
+136
âââââââââââ
2 1 1 0 2 11 4 1 2 2 21 1 3 1 2 20 2 1 2 1 12 2 2 1 4 11 2 2 1 1 3
âââââââââââ
=136
âââââââââââ
2 7 1 0 2 77 4 7 2 8 81 7 3 7 8 20 2 7 2 7 12 8 8 7 4 77 8 2 1 7 3
âââââââââââ (2.29)
ãšãªã.åŸã£ãŠ, C2(i, 2)ã¯ãããã
C2(1, 2) =136
(2 + 7 + 1 + 0 + 2 + 7) =1936
C2(2, 2) =136
(7 + 4 + 7 + 2 + 8 + 8) =3636
C2(3, 2) =136
(1 + 7 + 3 + 7 + 8 + 2) =2836
C2(4, 2) =136
(0 + 2 + 7 + 2 + 7 + 1) =1936
C2(5, 2) =136
(2 + 8 + 8 + 7 + 4 + 7) =3636
C2(6, 2) =136
(7 + 8 + 2 + 1 + 7 + 3) =2836
ãåŸããã.ããã§, η = 1ã®å ŽåãèããŠã¿ããš, é£æ¥è¡åã®ç©ã®æ§è³ªãã C2(i, 2)ã®å€ã¯, ã°ã©ã Gã®å šãŠã®ç¹ã
ãç¹ iã«è³ã 2以äžã®æ©éãäœæ¬ããã, ãè¡šã, η = 6ã®å Žåã«ã¯, é·ã 1ã®æ©éã®æ¹ã, é·ã 2ã®æ©éãããå©çšäŸ¡å€ãé«ããšããããšã§ãããã, ããã§åŸãããçµæã¯, å©çšäŸ¡å€ããèæ ®ã«å ¥ããå Žåã®å°äžéåé§ iã®å©çšé »åºŠ (ä¹å®¢é)ãè¡šããŠãã. ãã®èŠ³ç¹ããã¯, é§ 2, 5ãæãä¹å®¢éãå€ã, 1, 4ãæãå°ãªã. ããã¯ã°ã©ã Gã®åœ¢ç¶ããæããã§ããã. ããã, ã°ã©ãã®ãµã€ãºã倧ãããªã, è€éã«ãªã£ãŠãã
ãã㯠30ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ã°, ããã§ã®ç³»çµ±çãªåææ¹æ³ãæå¹ãšãªã£ãŠãã.
ãªã, D(G) = 3ã§ãããã, W (3), åã³, C3(i, 3)ãã€ãã§ã«æ±ããŠãããš
W (3) =1η
A +1η2
A2 +1η3
A3
= W (2) +1η3
A3
=1
216
âââââââââââ
12 42 6 0 12 4242 24 42 12 48 486 42 18 42 48 120 12 42 12 42 612 48 48 42 24 4242 48 12 6 42 18
âââââââââââ
+1
216
âââââââââââ
2 6 3 3 3 56 6 8 3 9 73 8 4 5 7 43 3 5 2 6 34 9 7 6 6 85 7 4 3 8 4
âââââââââââ
=1
216
âââââââââââ
14 48 9 3 15 4748 30 50 15 57 559 50 22 47 55 165 15 47 14 48 915 57 55 48 30 5047 55 16 9 50 22
âââââââââââ
(2.30)
åŸã£ãŠ
C3(1, 3) =1
216(14 + 48 + 9 + 3 + 15 + 47) =
136216
C3(2, 3) =1
216(48 + 30 + 50 + 15 + 57 + 55) =
255216
C3(3, 3) =1
216(9 + 50 + 22 + 47 + 55 + 16) =
199216
C3(4, 3) =1
216(3 + 15 + 47 + 14 + 48 + 9) =
136216
C3(5, 3) =1
216(15 + 57 + 55 + 48 + 30 + 50) =
255216
C3(6, 3) =1
216(47 + 55 + 16 + 9 + 50 + 22) =
199216
ãšãªã, ä¹å®¢éã«é¢ããé äœã¯ r = 2ã®å Žåãšå€ãããªã.ï¿œ
ᅵ
ᅵ
ᅵ
ããäŸé¡ 2.5-d ã (2004幎床æ å ±å·¥åŠæŒç¿ II(B) #2)
å³ 2.28(å³)ã®ã°ã©ãã®å蟺ã«å³ 2.29 ã®ãããªéã¿ãã€ãã. ãã®éã¿ã¯å°äžéã®ååºéã®ãéæ··é床ããè¡šããã®ãšã, ãã®å€ã倧ããªã»ã©, 客ã¯å¿«é©ã«ä¹è»ããããšãã§ãã. ãã®ããã«å蟺ããéã¿ä»ãããããã°ã©ããéã¿ä»ãã°ã©ããšåŒã¶ã, ãã®éã¿ä»ãã°ã©ãã®å Žåã«ã¯é£æ¥è¡åAã®åèŠ
çŽ [A]ij 㯠i, j éã®èŸºæ°ã§ã¯ãªã, éã¿ãä»ãã蟺æ°ã®åãšãªã. ããããµãŸããŠ, å³ 2.29ã®éã¿ä»ãã°ã©ã Gã«å¯ŸããŠé£æ¥è¡åAãæ±ãã.
(解çäŸ)
éã¿ä»ãã°ã©ãã«å¯Ÿããé£æ¥è¡åã®å®çŸ©ã«åŸãã°, åé¡æäžã®å³ 2.29ã«äžããããã°ã©ã Gã«å¯Ÿããé£æ¥
ãã㯠31ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
1
2
3
4
5
6
G0.60.16
0.5
0.06 1.00.3
0.6
0.3 0.76
å³ 2.29: å³ 2.28(å³) ã®ã°ã©ãã®å蟺ã«éã¿ãä»ããã°ã©ã G.
è¡åAã¯
A =
âââââââââââ
0.00 0.16 0.00 0.00 0.00 0.600.16 0.00 0.30 0.00 0.06 0.500.00 0.30 0.00 0.30 0.60 0.000.00 0.00 0.30 0.00 0.76 0.000.00 0.06 0.60 0.76 0.00 1.000.60 0.50 0.00 0.00 1.00 0.00
âââââââââââ
(2.31)
ãšãªã.ï¿œ
ᅵ
ᅵ
ᅵ
ããäŸé¡ 2.5-eã (2004幎床æ å ±å·¥åŠæŒç¿ II(B) #2)
äŸé¡ 2.5-dã§ã®é£æ¥è¡åã«å¯Ÿã, X â¡ A/ηãšããã (η = 6). ãã®ãšã, å³ 2.22ã®ã°ã©ã Gã«å¯Ÿã
Xâ = limrââXr = 0 (ãŒãè¡å) (2.32)
ãšãªãããšã瀺ã.
(解çäŸ)
Ar ã®ç¬¬ ij èŠçŽ ã¯
[Ar]ij =6â
l1=1
6âl2=1
· · ·6â
lrâ1=1
Ail1Al1l2Al2l3 · · ·Alrâ2lrâ1Alrâ1j (2.33)
ãšæžãã. ãšããã§, è¡åAã®èŠçŽ ãå šãŠ 1ã§ããå Žåã«ã¯
[Ar]ij =6â
l1=1
6âl2=1
· · ·6â
lrâ1=1
1 = 6râ1 (2.34)
ãšãªã (η = 6ã§ããããšã«æ³šæ), è¡åX = A/η㮠rä¹ã®ç¬¬ ij èŠçŽ ã¯
[Xr]ij =6râ1
6r=
16
(2.35)
ãã㯠32ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãšãªã, æéå€ãæ®ã. ããã, ä»ã®å Žå, åèŠçŽ 㯠1以äžã§ãããã, Rã 1以äžã®å®æ°ãšã㊠[Ar]ij ã¯æ¬¡ã®ããã«è©äŸ¡ã§ãã.
[Ar]ij =6â
l1=1
6âl2=1
· · ·6â
lrâ1=1
Ail1Al1l2Al2l3 · · ·Alrâ2lrâ1Alrâ1j †6râ1
(1R
)r
(2.36)
åŸã£ãŠ, è¡åXr ã®ç¬¬ ij èŠçŽ ã¯
[Xr]ij †16
(1R
)r
â 0 (r ââ) (2.37)
ãšãªã. åŸã£ãŠ
Xâ = limrââXr = 0 (2.38)
ãæç«ããããšãããã.ï¿œ
ᅵ
ᅵ
ᅵ
ããäŸé¡ 2.5-f ã (2004幎床æ å ±å·¥åŠæŒç¿ II(B) #2)
Xâ = 0ãšãªã (åäœè¡åã§ã¯ãªã)æ£æ¹è¡åX ã«å¯Ÿã
X + X2 + · · · =ââ
k=0
Xk = (I âX)â1 â I (2.39)
ãæãç«ã€ããšã瀺ã. ãã ã, I ã¯åäœè¡åã§ãã. ãŸã, ãã®äºå®ãçšããŠ, äŸé¡ 2.5-dã§æ±ããé£
æ¥è¡åã«å¯ŸãW (â)ãèšç®ãã.
(解çäŸ)
次ã®æçåŒã«çç®ãã.
I = (I + X + X2 + · · ·)â (X + X2 + · · ·)= (I âX) + (I âX)X + (I âX)X2 + · · ·= (I âX)(I + X + X2 + · · ·) (2.40)
åŸã£ãŠ
I + X + X2 + · · · = (I âX)â1 (2.41)
ããªãã¡
X + X2 + · · · =ââ
k=1
Xk = (I âX)â1 â I (2.42)
ãæãç«ã€.ããã§, ãã®çµæãçšããŠW (â)ãèšç®ããããšã«ããã. ããé¢åã§ããã,ã決ããŠé£ããã¯ãªã
èšç®ã®çµæ
W (â) =ââ
k=1
Xk = (I â (A/η))â1 â I
ãã㯠33ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
=
âââââââââââ
0.0117 0.0363 0.0038 0.0026 0.0190 0.10740.0363 0.0118 0.0541 0.0068 0.0319 0.09330.0038 0.0541 0.0714 0.0653 0.1146 0.02400.0026 0.0068 0.0653 0.0210 0.1400 0.02410.0190 0.0319 0.1146 0.1400 0.0597 0.18120.1074 0.0933 0.0240 0.0241 0.1812 0.0487
âââââââââââ
(2.43)
ãåŸãããã®ã§, ã¿ãŒããã«å®¹éã¯
Câ(1,â) = 0.1808
Câ(2,â) = 0.2341
Câ(3,â) = 0.2793
Câ(4,â) = 0.2598
Câ(5,â) = 0.5463
Câ(6,â) = 0.4786
ã®ããã«æ±ãŸã.ï¿œ
ᅵ
ᅵ
ᅵ
ããäŸé¡ 2.5-g ã (2004幎床æ å ±å·¥åŠæŒç¿ II(B) #2)
äŸé¡ 2.5-f ã®çµæããå³ 2.29ã®é£çµã°ã©ã Gã§äžããããå°äžéè·¯ç·å³åã³, åé§ ã§ã®ä¹å®¢éçã«é¢ããŠäœãèšããã ? ãŸã, ããã§ã®ã°ã©ãçè«çèå¯ãã, ãã®å°äžéãããå¿«é©ãªãã®ãšããããã«ã¯ã©ã®ãããªæ¹åç¹ãèãããã, ãèªç±ã«è«ãã.
(解çäŸ)
é§ 5ãã¿ããš, äŸãã°é§ 3ãšæ¯ã¹ãŠé§ 5ã«ã€ãªããåè·¯ç·ã®éæ··é床ãå°ããã, äžæ¹ã§, ã¿ãŒããã«å®¹éã¯å šãŠã®é§ ã§æ倧ã§ãã. åŸã£ãŠ, ãã®ã¿ãŒããã«å®¹éã®å€ã«åŸãã°, é§ 5ã«ã€ãªããè·¯ç·ãæŽåã (äŸãã°, åè»æéãããŸã調ç¯ãããªã©ããŠ), éæ··é床ãäžããŠããäŒæ¥åªåããã®å°äžéã«ã¯å¿ èŠã§ãããšèšãã.
ãã㯠34ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäžï¿œ
ᅵ
ᅵ
ᅵ
ããäŸé¡ 2.6ã (2003幎床æ å ±å·¥åŠæŒç¿ II(B) #1)
ã°ã©ãã®é£æ¥è¡åãšæ¥ç¶è¡åã«é¢ããŠä»¥äžã®åé¡ (1)ïœ(5)ã«çãã.
(1)次ã®é£æ¥è¡å A :
A =
ââââââ
0 1 0 11 0 2 10 2 0 11 1 1 0
ââââââ (2.44)
ãæã€ã°ã©ããæã.(2)次ã®æ¥ç¶è¡å G :
G =
ââââââ
1 0 00 1 00 0 11 1 1
ââââââ (2.45)
ãæã€ã°ã©ããæã.(3)ã«ãŒããæããªãã°ã©ãã®é£æ¥è¡åã«ãããä»»æã®è¡ãŸãã¯åã®èŠçŽ åãã該åœããã°ã©ãã«é¢ããŠäœãããããçãã.
(4)ã«ãŒããæããªãã°ã©ãã®æ¥ç¶è¡åã«ãããä»»æã®è¡ã®èŠçŽ åãã該åœããã°ã©ãã«é¢ããŠäœãããããçãã.
(5)ã«ãŒããæããªãã°ã©ãã®æ¥ç¶è¡åã«ãããä»»æã®åã®èŠçŽ åãã該åœããã°ã©ãã«é¢ããŠäœãããããçãã.
(解çäŸ)
(1)é£æ¥è¡åã®å®çŸ©ã«åŸã£ãŠã°ã©ããæããš, å³ 2.30ã®ããã«ãªã.
12
34
å³ 2.30: åé¡ã®é£æ¥è¡åãæã€ã°ã©ã.
(2)äžããããæ¥ç¶è¡åã®ç¬¬ 1ïœ3è¡ã®ããããã®èŠçŽ åã¯å ±ã« 1ã§ããããš, ãããŠç¹ 1, 2, 3ã«ã¯ãããã蟺 1, 2, 3ãæ¥ç¶ãããŠããããšãã, ãŸã, å³ 2.31ã®å·ŠåŽã®ãããªç¶æ³ã«ãªã£ãŠããããšãããã.äžæ¹, æ¥ç¶è¡åã®ç¬¬ 4åã®èŠçŽ å㯠1 + 1 + 1 = 3ã§ããããšãã, ç¹ 4ã«ã¯èŸº 3æ¬ãæ¥ç¶ãããŠããããšãããã. 以äžãèæ ®ãããšå³ 2.31ã®å³åŽãšãªã, ãããæ±ããã°ã©ããšãªã.
(3) 1ã€ã®ç¹ã«å ¥ã, ãããã¯åºã蟺ã®æ¬æ°.(4)åç¹ã«å ¥ã蟺ã®æ¬æ°.(5) 1ã€ã®èŸºã«ä»ããç¹ã®æ°. åŸã£ãŠ, ååã®èŠçŽ åã¯æå°ã§ 1, æ倧ã§ã 2ã§ãã.
ãã㯠35ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
1
1
22
3
34
1
23
1
23
4
å³ 2.31: ç¹ 1, 2, 3 ã«æ¥ç¶ãããŠãã蟺ã®æ¬æ°ããããã 1 æ¬ãã€ã§ããããšãã, ãŸãå·Šå³ãŸã§ããã. ã€ãã§, æ¥ç¶è¡åã®ç¬¬ 4è¡ã®èŠçŽ åã 3 ã§ããããšãã, å³å³ãæçµçãªçããšãªã.
ᅵ
ᅵ
ᅵ
ᅵ
ããäŸé¡ 2.7 ã (2003幎床æ å ±å·¥åŠæŒç¿ II(B) #1)
ã©ãã«ä»ãåçŽã°ã©ãã«ã€ããŠä»¥äžã®åé¡ (1)ïœ(3)ã«çãã.
(1) 3ç¹ã®ã©ãã«ä»ãã°ã©ãã¯ä»¥äžã®å³ã®ããã«æãã, ãã®ç·æ°ã¯ 8ã§ãã.1
32
1
3 2
1
3 2
1
32
1
3 2
1
32
1
32
1
32
ãããèžãŸããŠ, 4ç¹ã®ã©ãã«ä»ãã°ã©ããåæããŠæã, ãã®ç·æ°ãæ±ãã.(2)äžè¬ã« nç¹ã®ã©ãã«ä»ãã°ã©ãã®ç·æ°N (n)ã¯
N (n) = 2n(nâ1)
2 (2.46)
ã§ããããšã瀺ã. ãã ã, å¿ èŠã§ããã°å ¬åŒ :
(a+ b)n =nâ
k=0
nCk akbnâk (2.47)
ãçšããããš.(3) nç¹ã®ã©ãã«ä»ãã°ã©ãã®äžã§ã¡ããã©mæ¬ã®èŸºãæã€ã°ã©ãã®ç·æ°ãæ±ãã.
(解çäŸ)
(1)çç¥.(2) nç¹ã®ã©ãã«ä»ãåçŽã°ã©ãã«ãããŠå¯èœãªèŸºã®æ¬æ°ã¯, nç¹ã®äžããä»»æã® 2ç¹ãéžã¶æ¹æ³ã®æ°ã§ãããã
nC2 =n(nâ 1)
2(2.48)
ã§ãã. åŸã£ãŠ, nç¹ã®ã©ãã«ä»ãåçŽã°ã©ãã®ç·æ° N (n)ã¯, ç·æ° n(nâ 1)/2æ¬ã®èŸºã®äžãã, 1æ¬,
ãã㯠36ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
2æ¬, · · ·, n(nâ 1)/2æ¬ã®èŸºãéžãã§ã°ã©ããäœãå Žåã®æ°ã§ãããã
N (n) = n(nâ1)2
C0 + n(nâ1)2
C1 + n(nâ1)2
C2 + · · ·+ n(nâ1)2
Cn(nâ1)2
=
n(nâ1)2â
k=0
n(nâ1)2
Ck (2.49)
ãšããã§, 2é å®ç :
(a+ b)n =nâ
k=0
nCkakbkân (2.50)
㧠a = b = 1ãšããã°
2n =nâ
k=0
nCk (2.51)
ãåŸãããã, (2.49)ã¯äžåŒã§ n â n(nâ 1)/2 ãšãããã®ã«ä»ãªããªãã®ã§n(nâ1)
2âk=0
n(nâ1)2
Ck = 2n(nâ1)
2 (2.52)
ã§ãã, ããã nç¹ãããªãåçŽã°ã©ãã®ç·æ°ã§ãã.(3) n(nâ 1)/2ã®å šãŠã®èŸºã®å¯èœã®äžã§, mæ¬ã®ã¿ãéžã¶å Žåã®æ°ãªã®ã§
n(nâ1)2
Cm =
{n(nâ1)
2
}!
m!{
n(nâ1)2 âm
}!
(2.53)
ãšãªã.
ᅵ
ᅵ
ᅵ
ᅵ
ããäŸé¡ 2.7 ã (2007幎床 æŒç¿åé¡ 2 )
次ã®åã (1)(2)ã«çãã.
(1) (3, 3, 3, 3, 3, 3, 3, 3, 3, 3)ã¯ã°ã©ãçã? çç±ãšãšãã«ç€ºã. ãŸã, ãã®ã°ã©ãã®é£æ¥è¡å, æ¥ç¶è¡åãæžã.
(2)å®å š 2éšã°ã©ã K3,3,K4,4 ãç°ãªã 2éãã«æã, ãã®äž¡è ãååã§ããããšãäŸé¡ 2.2ã® 1. ã«åŸã£ãŠç€ºã.
(解çäŸ)
(1)次æ°å (3, 3, 3, 3, 3, 3, 3, 3, 3, 3)ãæã€ã°ã©ãã¯æ¬¡å³ 2.32ã«äžããããŒã¿ãŒã¹ã³ã»ã°ã©ãã§ãã. äžè¬çã«ã°ã©ããäžããããå Žåã«, ãã®æ¬¡æ°åãæ±ããããšã¯ç°¡åã§ããã, éã«æ¬¡æ°åãäžããããéã«, ãããã°ã©ãçã§ããã, ããã«ã°ã©ããæãã®ã, ã¯é£ãã課é¡ã§ãã. ã°ã©ãçã§ããããšã®ç³»çµ±çãªå€å®æ¹æ³ã®èå¯ã«é¢ããŠã¯ä»åŸã®æŒç¿åé¡ã§æ±ãããšã«ãã.
(2) K3,3ã«é¢ããŠã¯æ¢ã«è¿°ã¹ãã®ã§, ããã§ã¯, K4,4ãæ¬¡å³ 2.33ã®ãã㪠2éãã®æãæ¹ãããå Žåã®ååæ§ãè°è«ããããšã«ããã. ãã®ãšã, ã°ã©ã G1,G2éã®åååå Ξ, Ïã
Ξ(1) = a, Ξ(2) = c, Ξ(3) = e, Ξ(4) = g, Ξ(5) = h, Ξ(6) = b, Ξ(7) = d, Ξ(8) = f (2.54)
Ï(15) = ah, Ï(16) = ab, Ï(17) = ad, Ï(18) = af (2.55)
Ï(25) = ch, Ï(26) = cb, Ï(27) = cd, Ï(28) = cf (2.56)
Ï(35) = eh, Ï(36) = eb, Ï(37) = ed, Ï(38) = ef (2.57)
Ï(45) = gh, Ï(46) = gb, Ï(47) = gd, Ï(48) = gf (2.58)
ãã㯠37ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
å³ 2.32: ããŒã¿ãŒã¹ã³ã»ã°ã©ã.
G1
G2
1 2 3 4
5 6 7 8
a
b
c
d
e
f
g
h
å³ 2.33: K4,4 ã® 2 éãã®æãæ¹.
ãšéžã¹ãããšã«æ³šæããã°, 確ãã«ãã®ååã«å¯Ÿã, G1,G2 ã®æ¥ç¶é¢æ°ã ÏG1 , ÏG2 ãšãããš
ÏG1(15) = 15 â ÏG2(Ï(15)) = ÏG2(ah) = ah = Ξ(1)Ξ(5) (2.59)
çãæç«ããã®ã§, 確ãã«ã°ã©ã G1,G2 ã¯ååã§ãã.
ãã㯠38ããŒãžç®
39
第3åè¬çŸ©
3.1 æ§ã ãªã°ã©ãã®äŸ
ãã®ç¯ã§ã¯äžè¬çã¯ã°ã©ã Gãè«ããã®ã§ã¯ãªã, æ§ã 㪠(ç¹æ®ãª)ã°ã©ããäŸããšã£ãŠèª¬æã, åã ã®ã°ã©ãã®ç¹åŸŽãèŠãŠããããšã«ããã. ããã§ã¯, åŸã®ãã®è¬çŸ©ã§é »åºããã°ã©ããšãã®æ§è³ªãç°¡åã«è¿°ã¹ãã, å ·äœçãªå¿çšäŸ, åã³, 詳ããæ§è³ªã«é¢ããŠã¯è¿œã èŠãŠè¡ãããšã«ãªã. ããã, ããã§åºãŠããåã°ã©ãã®ååãšå€§ãŸããªæ§è³ªãæŒãããŠãããš, åŸã®åŠç¿ãã¹ã ãŒãºã«é²ãã§ããã.
3.1.1 空ã°ã©ã
空ã°ã©ã (null graph) : 蟺éåã空ã§ããã°ã©ã (ãç¹ã®ã¿ãããªãã°ã©ãããããã¯ã蟺ã®ãªãã°ã©ãã), æ°åŒã§è¡šçŸãããªãã°, nç¹ãããªã空ã°ã©ã㯠Nn ãšãªã. å³ 3.34ã« N4 ã®äŸãèŒãã.
N 4
å³ 3.34: 空ã°ã©ã N4.
3.1.2 å®å šã°ã©ã
å®å šã°ã©ã (complete graph) : çžéãªã 2ã€ã®ç¹ãå šãŠé£æ¥ããŠããåçŽã°ã©ã (ã«ãŒããå€é蟺ãå«ãŸãªãã°ã©ã). (â» é£ããèšããš â âv,vâ² â V (G), v ï¿œ= v
â²ã«å¯Ÿã, v, v
â²ã䞡端ãšãã蟺ãå¯äž 1åååš
ããã°ã©ã.) åŒã§ã¯ nåã®ç¹ãããªãå®å šã°ã©ã㯠Knãšè¡šçŸããã.
nåã®ç¹ãããªãå®å šã°ã©ãKnã®èŸºã®ç·æ°ã¯, 1, 2, · · · , nåã®ç¹ã®äžããä»»æã« 2ç¹éžãã§çµã¶å Žåã®æ°,ããªãã¡, nC2 = n(nâ 1)/2åã§ãã. å³ã®äŸã§èšããš, n = 4ã®å Žåã«ã¯ 6æ¬, n = 5ã®å Žåã«ã¯ 10æ¬ã§ãã, ããã¯å³ 3.35ããçŽã¡ã«ç¢ºèªã§ãã (ä»å¹ŽåºŠã® äŸé¡ 1.4 (2)ãããããŠåç §ã®ããš).
3.1.3 æ£åã°ã©ã
r-æ£åã°ã©ã (regular graph) : å šãŠã® v â V (G)ã«å¯ŸããŠ, dev(v) = rã§ããã°ã©ã. å¹³ããèšããš,ã©ã®ç¹ã®æ¬¡æ°ãå šãŠå ±éã« rã§ããã°ã©ã. (⻠泚: æ£åã°ã©ããšãã芳ç¹ããã¯, Nn㯠0-æ£åã°ã©ã, Cn
㯠2-æ£åã°ã©ã, Kn 㯠(nâ 1)-æ£åã°ã©ããšããããšã«ãªã.)
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
K
K
4
5
å³ 3.35: å®å šã°ã©ã K4 åã³ K5.
3-regular graph2-regular graph
å³ 3.36: æ¬¡æ° 3 ã®æ£åã°ã©ã (å·Š), åã³, æ¬¡æ° 2 ã®æ£åã°ã©ãïŒå³) ã®äŸ.
3.1.4 éè·¯ã°ã©ã
éè·¯ã°ã©ã (cycle graph) : æ¬¡æ° 2ã®æ£åé£çµã°ã©ã. åŒã§ã¯ Cn ã®ããã«è¡šèšããã.
C 6
å³ 3.37: éè·¯ã°ã©ã C6.
3.1.5 éã°ã©ã
éã°ã©ã (path graph) : éè·¯ã°ã©ã Cnããäžã€ã®èŸºãé€ããŠåŸãããã°ã©ã. åŒã§è¡šçŸãããš Pnãš
ãªã.
3.1.6 è»èŒª
è»èŒª (wheel) : Cnâ1 ã«æ°ããç¹ vãäžã€å ã, vãšä»ã®å šãŠã®ç¹ãšã蟺 (ãã¹ããŒã¯ããšåŒã°ãã)ã§çµãã§ã§ããã°ã©ã. åŒã§è¡šèšãããšWn ãšãªã.
ãã㯠40ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
C
P
6
6
å³ 3.38: éè·¯ã°ã©ã C6 ããæ¬¡æ° 6 ã®éã°ã©ã P6 ãäœæããéçš.
C W5 6
å³ 3.39: éè·¯ã°ã©ã C5 ããæ¬¡æ° 6 ã®è»èŒªW6 ãäœæããéçš.
3.1.7 ããŒã¿ãŒã¹ã³ã»ã°ã©ã
ããŒã¿ãŒã¹ã³ã»ã°ã©ã (Petersen graph) ã¯å³ã®ãããªç¹æ®ãªåœ¢ç¶ãæã€ã°ã©ãã§ããã, äŸé¡ 2.7(1)ã§ãèŠãããã«, ä»åŸã®æŒç¿åé¡çã§ãã°ãã°çŸããããšã«ãªã 6 .
å³ 3.40: ããŒã¿ãŒã¹ã³ã»ã°ã©ã.
3.1.8 äºéšã°ã©ã
äºéšã°ã©ã (bipartite graph) : ã°ã©ã Gã®ç¹éåã 2ã€ã®çŽ ãªéå A,Bã«åå²ã, Gã®å šãŠã®èŸºã¯Aã®ç¹ãš Bã®ç¹ãçµã¶ããã«ã§ãããšãã. ãã®ãšã, ã°ã©ã Gã¯äºéšã°ã©ãã§ãããšãã.
3.1.9 å®å šäºéšã°ã©ã
å®å šäºéšã°ã©ã (complete bipartite graph) : Aã®åç¹ã Bã®åç¹ãšã¡ããã© 1æ¬ã®èŸºã§çµã°ããŠããäºéšã°ã©ã.å³ã®ããã«ç¹ãé»äžžãšçœäžžã§ 2ã€ã®éåã«åãããšã, é»ã®ç¹ rå, çœã®ç¹ såãããªãå®å šäºéšã°ã©ãã¯
Kr,s ãšè¡šèšããã. åœç¶ã§ããã, Kr,s ã«ã¯ (r + s)åã®ç¹ãš rsæ¬ã®èŸºããã.
6 Petersen graph ã¯æç§æžã§ã¯ãããŒã¿ãŒã¹ã³ã»ã°ã©ãããšçºé³, æ¥æ¬èªè¡šèšãããŠããã, ä»ã®å°éæžã§ã¯ããºãã«ã»ã³ã»ã°ã©ãããšçºé³, æ¥æ¬èªè¡šèšãããŠãããã®ãå€ã (ããã, ãã¡ãã®æ¹ãå€æ°æŽŸã§ãã)
ãã㯠41ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
A
B
G
å³ 3.41: äºéšã°ã©ã G ã®äŸ. å šãŠã®èŸºã®ç«¯ç¹ã¯é»äžžãšçœäžžã®ãã¢ã§ãªããŠã¯ãããªã.
KK
1,3
2,3
K 3,3 K 4,3
å³ 3.42: å®å šäºéšã°ã©ã K1,3, K2,3, K3,3, K4,3.
3.1.10 k-ç«æ¹äœ
k-ç«æ¹äœ (k-cube) : ai = 0 or 1ã§ãããã㪠1ã€ã®å (ãã¯ãã«) (a1, a2, · · · , ak)ã«äžã€ã®ç¹ã察å¿ãã, äžã€ã ãç°ãªãæå ai ãæã€äºã€ã®ãã¯ãã«ã«å¯Ÿå¿ããäºã€ã®ç¹ã蟺ã§çµã°ãããããªæ£åäºéšã°ã©
ã. åŒã§è¡šèšãããš Qk ãšãªã.â Qk 㯠2k åã®ç¹ãš, k2kâ1 æ¬ã®èŸºãæã€7 .
3.1.11 åçŽã°ã©ãã®è£ã°ã©ã
åçŽã°ã©ãã®è£ã°ã©ã (complement) : åçŽã°ã©ã Gã®è£ã°ã©ã Gãšã¯, ç¹éå V (G)ãæã¡, Gã®2ç¹ãé£æ¥ããã®ã¯Gã«ããããããã® 2ç¹ãé£æ¥ããŠããªããšã, ãã€, ãã®ãšãã«éããããªåçŽã°ã©ããèšã.
⢠å®å šã°ã©ãã®è£ã°ã©ãã¯ç©ºã°ã©ãã§ãã. (ãã ã, éã¯èšããªã).
⢠å®å šäºéšã°ã©ãã®è£ã°ã©ã㯠2ã€ã®å®å šã°ã©ãã®åã§ãã.
3.2 ã°ã©ãã«ãŸã€ããããã€ãã®ããºã«
ããã§ã¯, ã°ã©ããçšããŠå¹ççã«è§£ãããšãã§ãã 2ã€ã®ããºã«ã玹ä»ããã.
7 (0, 0, 0, 1, 0, 0, · · · , 0), (0, 0, 0, 0, 1, 0, · · · , 0), · · · ã®åãã¯ãã«ã® k æåã®ãã¡ã®ã©ã®æåãé£ãéãããšããå Žå k éã, æ®ãã® k â 1 æåã®äžŠã³æ¿ã 2kâ1 éãã®ç©ã§ k2kâ1 æ¬ã®èŸºã®æ°ãšãªã.
ãã㯠42ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
z
x
y
(0,0,1)
(0,1,1)
(1,1,1)(1,0,1)
(0,0,0)
(1,0,0) (1,1,0)
(0,1,0)
100 101
110
111
010
001
000 001
Q
Q
3
3
å³ 3.43: 3-ç«æ¹äœ. å³ã® G1 åã³ G2 ã¯å圢ã§ãã.
u
y
x w
v
y
x w
v
u
å³ 3.44: åçŽã°ã©ããã, ãã®è£ã°ã©ããäœæããéçš.
3.2.1 8ã€ã®åã®é 眮åé¡
å³ 3.46ã®ãã㪠8ã€ã®åã®äžã« A,B,C,D,E, F,G,Hã® 8ã€ã®æåãå ¥ããããšãèãã. ãã ã, ã¢ã«ãã¡ãããé ã§é£ã«ããæåã¯äºãã«é£æ¥ããªãããã«çœ®ã. ãã®ãšã, ãã®ãšã, é©åãªé 眮ã®ä»æ¹ãçãã. ã¡ãªã¿ã«, å¯èœãªé 眮ã®ç·æ°ã¯ 8! = 46320éãã§ãããã, å šãŠã®å Žåãããã¿ã€ã¶ãã«è©ŠããŠã¿ãæŠç¥ã¯é©åã§ã¯ãªãããšã«æ³šæããã. (ççŒç¹) :
⢠Aãš Hã®é 眮ã®ä»æ¹ã¯æãã (çåŽã«ããçžæãããªããã).
⢠å³ã®#1, #2ã®åãžã®é 眮ãæãé£ãã (次æ°ãæ倧ã ãã).
(解ç) :
1. æã次æ°ãå€ãé£ãã, #1,#2ã«ãããã A,Bãé 眮ãã.2. ã¢ã«ãã¡ããã㧠A, Hã®é£ã«ãã Båã³ Gããããã#8,#7ã«ããããé 眮ãã.3. æ®ãã®æåããããããã¢ã«ãã¡ãããã§é£ãåããªãããã«é 眮ãã. äŸãã°, #3 = C,#4 =
E,#5 = D,#6 = Fã®ããã«é 眮ããã°ãã.
ãã㯠43ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
K K1,3 1,3
å³ 3.45: å®å šäºéšã°ã©ã K1,3 ãšãã®è£ã°ã©ã.
#3 #4
#1 #2
#5 #6
#7#8
å³ 3.46: 8 ã€ã®åã®é 眮åé¡ã®å³.
3.2.2 4ã€ã®ç«æ¹äœããºã«
(åé¡)å³ã®ãããªç«æ¹äœã®å±éå³ : cube1, cube2, cube3, cube4
R
G
Y
B R R
B
R
Y
Y G G
G
B
Y
B R B
B
R
Y
R G Y
cube1 cube2
cube3 cube4
ããç«æ¹äœãäœã, ããããç©ã¿äžããŠ, åè§æ±ãäœã, åè§æ±ã® 4ã€ã®åŽé¢ããããã« 4è²å šãŠãè¡šãããããªåè§æ±ã®ç©ã¿äžãæ¹ãèŠã€ããã.
以äžã®åã (1)ïœ(3)ã«çã, ãã®ãããªé 眮ãæ±ãã.
(1)åç«æ¹äœã 4ç¹ãããªãã°ã©ãã§è¡šã, R,B,G,Yã®åç¹ã¯åè²ã«å¯Ÿå¿ãã, å¹³è¡ãªé¢ã«å¡ãããè²ã«å¯Ÿå¿ããç¹ã¯èŸºã§çµã¶. ãã®ããã«ããŠåºæ¥äžããã°ã©ãã cube1, cube2, cube3, cube4 ã«å¯ŸããŠæã.
(2) (1)ã§æ±ããã°ã©ããéãåãããã°ã©ã Gãæã.(3) Gã®éšåã°ã©ã H1,H2ãèŠã€ãåºã, ç«æ¹äœ : cube1, cube2, cube3, cube4 ãç©ã¿äžããŠ, åè§æ±ãäœã, åè§æ±ãäœã£ããšã, ãã®åè§æ±ã® 4ã€ã®é·æ¹åœ¢ã®åŽé¢ã«ãããã 4è²å šéšãçŸãããããªç©ã¿äžãæ¹ã瀺ã.
ãã㯠44ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
(解ç)
(1)ãŸã, cube1, cube2, cube3, cube4 ã«çžåœããã°ã©ãã¯ããããå³ 3.47 ã®ããã«ãªã.
R B
G Y
R B
G Y
R B
G Y
R B
G Y
cube1 cube2
cube3 cube4
R B
G Y
3
1
3
42
4
1
2
3
21
4
å³ 3.47: cube1, cube2, cube3, cube4 ã«ããããçžåœããã°ã©ã (å·Š), åã³, ããããã®ã°ã©ããéãåãããããšã«ããåŸãããã°ã©ã G(å³).
(2) (1)ã§åŸãããã°ã©ããéãåããããš, å³ 3.47(å³)ã® GãåŸããã.(3)å cube ã®èŸºãã¡ããã© 1æ¬ãã€å«ã¿, å ±éãªèŸºãç¡ã, æ¬¡æ° 2ã®æ£åã°ã©ããšããŠã®ã°ã©ã Gã®éšåã°
ã©ã H1,H2ãéžã¶ãš, å³ 3.48ã®ããã«ãªã. ãããã®éšåã°ã©ã H1 (FB), H2 (LR)ãçšããŠ, cube1,
R B
G Y
R B
G Y
1
34
2
41
2
3
H H1 2
B
R
Y
G
G
Y
B
R
Y
B
G
R
R
G
Y
B
F L B R
4
3
2
1
4
3
2
1
å³ 3.48: æ±ãã G ã®éšåã°ã©ã H1, H2 (å·Š), åã³, æ±ããç«æ¹äœã®ç©ã¿äžãæ¹ (å³).
cube2, cube3, cube4 ãç©ã¿äžãããšå³ 3.48(å³)ã®ããã«ãªã. ãããçãã§ãã.
ãã㯠45ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ᅵ
ᅵ
ᅵ
ᅵ
ããäŸé¡ 3.1 ã (2004幎床 æŒç¿åé¡ 3 )
å³ã«èŒããã°ã©ã Gã«é¢ããŠä»¥äžã®åãã«çãã.1
4
2
3
1
2
4
3
(1)ã°ã©ã Gã®æ¥ç¶è¡åãæ±ãã.(2)æ¥ç¶è¡åã®ååã®èŠçŽ ã®åã¯äœãæå³ããŠããã ?(3)æ¥ç¶è¡åã®åè¡ã®èŠçŽ ã®åã¯äœãæå³ããŠããã ?(4) ε(G)ãã°ã©ã Gã®èŸºæ°ãšãããš
âvâV (G)
deg(v) = 2ε(G)
ãæãç«ã€ããšã瀺ã.
(解çäŸ)
(1)å®çŸ©ã«åŸã£ãŠ, åé¡ã«äžããããã°ã©ãã®æ¥ç¶è¡åM ãæžãäžããš
M =
ââââââ
1 1 0 01 1 1 10 0 1 00 0 0 1
ââââââ
ã®ããã«ãªã.(2)äŸãã°, äžèšã®æ¥ç¶è¡åã®ç¬¬ 1è¡ç®ãèŠãŠã¿ããš, 第 1, 2åã« 1ãç«ã£ãŠãã. ããã¯ç¹ 1,2ã蟺 1ã§çµã°ããŠããããšãè¡šããŠãã. æ¥ç¶è¡åã®å®çŸ©ãã, ååã¯èŸºã®çªå·ãè¡šã, ååã« 1ãç«ã£ãŠããè¡ã該åœãã蟺ã«æ¥ç¶ããç¹ãè¡šããŠãã, 1ã€ã®èŸºã«æ¥ç¶ã§ããç¹ã®æ°ã¯åžžã« 2ã€ã§ãããã, æ¥ç¶è¡åã®ååã®æåã®åã¯åžžã« 2ã§ãããšããããšãã§ãã.
(3)æ¥ç¶è¡åã®å®çŸ©ãã, åè¡ã®æåã®åã¯åç¹ã®æ¬¡æ°ã®åãè¡šã.(4) (2)(3)ã®èå¯ãã, 次æ°ã®å
âvâV (G) deg(v) æ¥ç¶è¡åã®åè¡ã®æååãå šãŠã®è¡ã«å¯ŸããŠèšç®ããã
ã®ã«çãã, ããã¯æ¥ç¶è¡åã®å šãŠã®æåã足ãããã®ã§ãã. äžæ¹, æ¥ç¶è¡åã®ååã®èŠçŽ ã®åã¯åžžã« 2ã§ãã, åŸã£ãŠ, æ¥ç¶è¡åã®å šãŠã®æåã®ç·åã¯, 蟺ã®æ°ã® 2åããªãã¡ 2ε(G)ã§ãã, çµå±
âvâV (G)
deg(v) = 2ε(G)
ãæãç«ã€.
ãã㯠46ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ᅵ
ᅵ
ᅵ
ᅵ
ããäŸé¡ 3.2ã (2004幎床 æŒç¿åé¡ 3 )
å³ 2.14ã«èŒããå®å šã°ã©ã K5ã«ã€ããŠä»¥äžã®åãã«çãã.
(1)å³ 2.14ã®å®å šã°ã©ã K5ã® 5ã€ã®é ç¹ã«, æèšåãã«çªå· 1, · · · , 5ãå²ãåœãŠã. ãã®ãšã, ãã®å®å šã°ã©ãã®é£æ¥è¡åAãæ±ãã.
(2)ç¹ 1ãšç¹ 3ãçµã¶é·ã 2ã®æ©éã®æ°ã¯, A2ã®ç¬¬ (1, 3)-æåã«çããããšã瀺ã.(3)ç¹ 1ãšç¹ 3ãçµã¶é·ã 3ã®æ©éã®æ°ã¯, A3ã®ç¬¬ (1, 3)-æåã«çããããšã瀺ã.(4)äžè¬ã«, é£æ¥è¡åAãæã€åçŽã°ã©ã Gã® 2ç¹ i, j ãçµã¶é·ãK ã®æ©éã®æ°ã¯, AK ã®ç¬¬ (i, j)-æåã«çããããšã瀺ã.
(解çäŸ)
(1)å®å šã°ã©ã K5ã®é£æ¥è¡åAã¯
A =
ââââââââ
0 1 1 1 11 0 1 1 11 1 0 1 11 1 1 0 11 1 1 1 0
ââââââââ
ã®ããã«å¯Ÿè§æåããŒãã§ãã, é察è§æåã« 1ã䞊ãã è¡åãšãªã.(2)ãŸã, å³ã®å®å šã°ã©ãK5ããèå¯ããŠã¿ããš, ç¹ 1ãš 3ãçµã¶é·ã 2ã®æ©éã¯
[1] 1â 2â 3
[2] 1â 5â 3
[3] 1â 4â 3
ã® 3ã€ã§ãã.äžæ¹, é£æ¥è¡åã®èªä¹ãèšç®ããŠã¿ããš
A2 =
ââââââââ
4 3 3 3 33 4 3 3 33 3 4 3 33 3 3 4 33 3 3 3 4
ââââââââ
ãšãªã, ããããçŽã¡ã«A2 ã®ç¬¬ (1, 3)-æå㯠3ã§ããããšãããã. åŸã£ãŠ, é¡æã瀺ãã.(3) (2)ãšåæ§ã«, å°ã é¢åã§ããã, ãŸãã¯åé¡ã®å®å šã°ã©ãããç¹ 1,3ãçµã¶é·ã 3ã®æ©éãæ°ãäžããŠã¿ããš
[1] 1â 2â 1â 3
[2] 1â 3â 1â 3
[3] 1â 4â 1â 3
[4] 1â 5â 1â 3
[5] 1â 2â 5â 3
[6] 1â 2â 4â 3
ãã㯠47ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
[7] 1â 3â 2â 3
[8] 1â 3â 4â 3
[9] 1â 3â 5â 3
[10] 1â 4â 2â 3
[11] 1â 4â 5â 3
[12] 1â 5â 2â 3
[13] 1â 5â 4â 3
ã®ããã«ãªã, èš 13éãååšãã.äžæ¹, A3 ãèšç®ãããš
A3 =
ââââââââ
12 13 13 13 1313 12 13 13 1313 13 12 13 1313 13 13 12 1313 13 13 13 12
ââââââââ
ãšãªã, ãã®ç¬¬ (1, 3)-æå㯠13ãšãªã, é¡æã瀺ããã.(4)äžè¬ã« nç¹ãããªãåçŽã°ã©ãã®é£æ¥è¡åã®K ä¹, ã€ãŸã, AK ã®ç¬¬ (i, j)-æåã¯
[AK ]ij =nâ
k1=1
nâk2=1
· · ·nâ
kK=1
aik1ak1k2ak2k3 · · ·akKâ1kKakKj
ã§ãã, aik1 ã¯ç¹ iãš k1ãçµã¶éã®æ°ã§ããããšãã, äžèšã® [AK ]ij ã¯ç¹ i, jãçµã¶éã®æ°ã«çãã
ããšãããã.
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ᅵ
ããäŸé¡ 3.3 ã (2004幎床 æŒç¿åé¡ 3 )
å®å šäžéšã°ã©ãKr,s,tã¯ããããã«å±ããç¹ã®åæ°ã r, s, tã§ãã 3ã€ã®ç¹éåãããªã, ç°ãªãéåã«å±ããç¹ã¯å šãŠèŸºã§çµã°ããŠããã°ã©ãã§ãã. ãã®ãšã, 以äžã®åãã«çãã.
(1) K2,2,2åã³ K3,3,2 ãæã.(2) Kr,s,t ã«ã¯å šéšã§äœæ¬ã®èŸºããããçãã.
(解çäŸ)
(1)å®å šäžéšã°ã©ã K2,2,2 ãæããšå³ 3.49ã®ããã«ãªã (K3,3,2 ãåæ§ã«ããŠäœå³ã§ããã, ããã§ã¯çç¥.).
(2) Kr,s,tã®èŸºã®æ¬æ°ã¯ rs+ rt+ stæ¬ã§ãã.
ãã㯠48ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
AB
C
K 2,2,2
å³ 3.49: å®å š 3 éšã°ã©ã K2,2,2 ã®äœå³äŸ. K3,3,2 ãåæ§ã«ããŠäœå³ã§ããã, ããã§ã¯çç¥.
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ããäŸé¡ 3.4 ã (2005幎床 æŒç¿åé¡ 3 )
1. 次㮠(i)ïœ(v)ã®ã°ã©ããããå Žåã«ã¯ããã 1ã€æããŠæã (ç¡ãå Žåã«ã¯ãç¡ãããšæžã).(i) æ¬¡æ° 5ã®æ£åã°ã©ãã§ãããããªäºéšã°ã©ã.(ii) äºéšã°ã©ãã§ãããã©ãã³ã»ã°ã©ã.(iii) è»èŒªã§ããå®å šã°ã©ã.(iv) 11åã®ç¹ãã〠3次ã°ã©ã.(v)æ¬¡æ° 4ã®æ£åã°ã©ãã§K5,K4,4, Q4以å€ã®ã°ã©ã.
2. ããèªèº«ã®æã°ã©ããšå圢ãªåçŽã°ã©ãã¯èªå·±æ察 (self-complementrary) ã§ãããšãã.ãã®ãšã
(1) 4å, ãŸã㯠5åã®ç¹ããã€èªå·±æ察ã°ã©ããå šãŠæã.(2) 8åã®ç¹ãããªãèªå·±æ察ã°ã©ããèŠã€ãã.
(解çäŸ)
1.(i) æ¬¡æ° 5ã®æ£åã°ã©ãã§ããäºéšã°ã©ãã¯å³ 3.50ã®ãããªå®å šäºéšã°ã©ãK5,5 ãæãããã.
å³ 3.50: æ¬¡æ° 5 ã®æ£åã°ã©ãã§ããäºéšã°ã©ãã®äŸ.
(ii) äºéšã°ã©ãã§ãããã©ãã³ã°ã©ããšããŠã¯, å³ 3.51ã®ãããªç«æ¹äœãæãããã.(iii) è»èŒªã§ããå®å šã°ã©ãã¯å³ 3.52ã§ãã.(iv) ãŸãã¯, å³ 3.53ã«ç¹æ°ã n = 4, 6, 8, 10, 12ã®å Žåã® 3次ã®æ£åã°ã©ãã®äŸãèŒãã. ããã§åãããŠããåé¡ã¯èªç¶æ°å (a1, a2, · · · , an) = (3, 3, · · · , 3)ãã°ã©ãçã§ãããã©ãã, ã n = 11ã®å Žåã«ç¢ºãã, ã°ã©ãçã§ããå Žåã«ã¯å ·äœçã«ãã®å³ãæã, ãšèšãçŽãããšãã§ãã. ãã®å Žå, æ¡
ãã㯠49ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
å³ 3.51: äºéšã°ã©ãã§ãããã©ãã³ã°ã©ãã®äžäŸ.
å³ 3.52: è»èŒªã§ããå®å šã°ã©ã.
ææé¡ãã, ç¹æ° n, æ¬¡æ° 3ã®ã°ã©ãã®èŸºæ°mã¯
m =3n2
(3.60)
ã§ãã. ããã§, ãããå³ã§ç¢ºèªããŠã¿ããš, 確ãã«æç«ããŠããããšãããã. 蟺ã®æ°ã¯å¿ ãæŽæ°ã§ãªããã°ãªããªãã®ã§, ãã®åŒãæãç«ã€ããã«ã¯ nã¯å¶æ°ã§ãªããã°ãªããªã. åŸã£ãŠ, n = 11ã®å Žåã«ã¯å šãŠã®ç¹ã®æ¬¡æ°ã 3ã§ãããããªæ£åã°ã©ãã¯æããªãããšãçµè«ã€ãããã.
(v) æ¬¡æ° 4ã®æ£åã°ã©ãã§K5,K4,4, Q4以å€ã®ã°ã©ããšããŠã¯å³ 3.54 ã®ãããªæ£ 8é¢äœãæãããã.
2.
(1)ãŸã, ãã®è£ã°ã©ããèªå·±è£å¯Ÿã§ããããšãã, ãã®ã°ã©ãããã³å¯Ÿå¿ããè£ã°ã©ãã®å (ã°ã©ãã2ã€éãåããããã®) ãå®å šã°ã©ããšãªãããšã«çç®ãã. ãããš, ç¹æ°ã n ã§ããå®å šã°ã©ãã®
蟺æ°mãm = n(nâ 1)/2ã§ãããã, æ±ããã°ã©ãã®èŸºæ°ã¯ãã®åå, ããªãã¡, n(nâ 1)/4ã§ããããšãå¿ èŠã§ãã. åŸã£ãŠ, 蟺æ°ã¯æŽæ°ã§ãªããã°ãªããªãã®ã§, æ±ããã°ã©ãã®ç¹æ° n㯠kãæŽ
æ°ãšããŠ, n = 4kããã㯠nâ 1 = 4k ã§ãªããã°ãªããªã, ããªãã¡, æ±ããã°ã©ããèªå·±è£å¯Ÿã§ããããã«ã¯, ç¹ã®æ° nã n = 4kã n = 4k+ 1ã§ããããšãå¿ èŠã§ãã. k = 1ãšããå Žå, n = 4ãŸã㯠n = 5ãšãªãã, ãã®ãšãã®èªå·±è£å¯Ÿã°ã©ããå ·äœçã«æ±ãã, ãšããã®ãããã§ã®åé¡ã§ãã. ããã§, ãŸã n = 4ã®å Žåã«ã€ããŠèããŠã¿ããš, åç¹ã®æ¬¡æ°ã¯å€ç«ç¹ãçããŠã¯ãªããªãããã§ãããã, 1, 2ã«éãããããšã«æ³šæãã. æ¬¡æ° 1ã®ç¹ã®åæ°ã L, æ¬¡æ° 2ã®ç¹ã®åæ°ãM ãšãã
ã°, æ£ã®æŽæ° L,M ã¯æ¬¡ã®çåŒãèŠãããªããã°ãªããªã.
L+ 2M = 6 (3.61)
L+M = 4 (3.62)
ãããæºããçµã¿åãããšããŠã¯ (L,M) = (2, 2) ã§ãã, æ±ããèªå·±è£å¯Ÿã§ããã°ã©ãã®æ¬¡æ°åã¯(1, 1, 2, 2) ã®ã¿ã§ããããšãããã. ãããæºããã°ã©ããšããŠã¯å³ 3.55 ã®å·Šå³å®ç·ãæãããã(ããã®ã¿).
ãã㯠50ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
n=4, m=6 n=6, m=9
n=8, m=12n=10, m=15
n=12, m=18
å³ 3.53: ç¹ã®æ°ã n = 4, 6, 8, 10, 12 ã®å Žåã®æ£åã°ã©ã. ã¡ãªã¿ã«, n = 10 ã®å Žåã«ã¯åã«èŠããããŒã¿ãŒã¹ã³ã»ã°ã©ãããåœãŠã¯ãŸã. ãã®èŸºæ°ã¯ m = 15 ã§ãã.
å³ 3.54: æ¬¡æ° 4 ã®æ£åã°ã©ãã§ããæ£ 8 é¢äœ.
åæ§ã«ããŠ, n = 5ã®å Žåã«å¯Ÿã, åç¹ã®æ¬¡æ°ã¯ 1, 2ãŸã㯠3ã§ãããã, ãã®ããããã®æ¬¡æ°ãæã€ç¹ã®æ°ã L,M åã³ N ãšããã°, 次ã®çåŒ :
L+ 2M + 3N = 10 (3.63)
L+M +N = 5 (3.64)
ãæãç«ã€. ãããæºãã解㯠(M,L,N) = (1, 3, 1), (2, 1, 2)ã® 2ã€ã§ããã®ã§, å¯èœãªèªå·±è£å¯Ÿã°ã©ãã®æ¬¡æ°åãšããŠã¯ (3, 2, 2, 2, 1)ããã㯠(3, 3, 2, 1, 1) ã§ããã,åè ã§ã¯èªå·±è£å¯Ÿã°ã©ãã¯å®éã«ã¯æãã, åŸè ã«é¢ããŠã¯å³ 3.55ã®å³å³å®ç· (ããã®ã¿) ã察å¿ãã.
n=4 n=5
å³ 3.55: ç¹ã®æ°ã 4, ãŸã㯠5 ã§ãããããªèªå·±æ察ã°ã©ã. ç¹ç·ã§æãããã°ã©ããããããã®æã°ã©ããè¡šã.
â» è£è¶³ã³ã¡ã³ã:
ãã㯠51ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
n = 5ã®å Žåã«èªå·±è£å¯Ÿã°ã©ããæ±ããåé¡ã§, æ¬¡æ° 1, 2, 3ã®ç¹ã®åæ°ã L,M,N ãšãããšã
L+ 2M + 3N = 10 (3.65)
L+M +N = 5 (3.66)
ãšããŠ, å¯èœãªæ¬¡æ°åã L,M,N ⥠1ã®ç¯å²å ã§æ¢ããŸããã, L,M,N ã¯ãŒããåãããã®ã§, ãã®ç¯å²å ã§æ¢ãã°, M = 5, L = N = 0ãäžèšæ¹çšåŒãæºãããŸã. ãã®ãšãã®æ¬¡æ°å㯠(2, 2, 2, 2, 2)ãšãªã, å¯èœãªèªå·±è£å¯Ÿã°ã©ããšããŠå³ 3.56ã®ãããªãã®ãååšããããšã«ãªããŸã.
å³ 3.56: n = 5 ã®å Žåã®èªå·±è£å¯Ÿã°ã©ãã®ããäžã€ã®å¯èœæ§. å³ã®å®ç·ãšç Žç·ãããããäºãã«å圢ãšãªã£ãŠãã.
(2)åã«åŸãå¿ èŠæ¡ä»¶ã®åŒã§ k = 2ãšçœ®ããš n = 8ãåŸãããã®ã§, 8ç¹ãããªãèªå·±è£å¯Ÿã°ã©ããäžã€èŠã€ããã. ãã®é, 次ã®ãããªã¢ã«ãŽãªãºã (I)-(IV)ãçšããŠææã®ã°ã©ããèŠã€ããããšã«ããã.
(I) å³ 3.57 ã®ããã« 8åã®ç¹, 1, · · · , 8ãæèšåãã«äžŠã¹ã.
1
2
3
4
5
6
7
8
å³ 3.57: ããã§åŸãããèªå·±è£å¯Ÿã°ã©ã (å®ç·) ãšãã®å圢ã°ã©ãïŒç Žç·). èªå·±è£å¯Ÿã®å®çŸ©ãã, å®ç·ãšç Žç·ã足ãããã®ã 8 次ã®å®å šã°ã©ã K8 ãšãªãããšã«æ³šæ.
(II) 8åã®ç¹ã®äžã§å¥æ°çªç®ã®ç¹ (1, 3, 5, 7) ã«é¢ããŠå®å šã°ã©ããäœã (èªå以å€ã®ç¹å šãŠãšåã 1æ¬ã®èŸºã§çµã°ãã).
(III) å¥æ°çªç®ã®ç¹ã®ãããããš, ãã®ç¹ã« 1ãå ããå¶æ°çªç®ã®ç¹ (äŸãã°, ç¹ 1ãªãã°ç¹ 2, ç¹ 3ãªãã°ç¹ 4)ãçµã¶. ãã®æç¹ã§èŸºã®æ°ã¯ 10ã§ãã, 8åã®ç¹ãå šãŠã€ãªãã£ãé£çµã°ã©ããåºæ¥äžãã. åŸã£ãŠ, èªå·±è£å¯Ÿã°ã©ããäœãããã«ã¯ããš 14â 10 = 4æ¬ã®èŸºãä»ã足ãã°ãã.
(IV) æåŸã®ã¹ããããšããŠ, å¶æ°çªç®ã®åç¹ãš, ãã®ç¹ã®çªå·ãã©ã¹ 3ã«çžåœããçªå·ã®ç¹ãçµã¶ (ç¹2ãšç¹ 5ã, ç¹ 8㯠8 + 3 = 11ã§ããã, 11â 8 = 2ã§ãããã, ç¹ 8ãšç¹ 2ãçµã¶ããšãšçŽæãã). ãã®æäœ (I)-(IV)ã§èš 14æ¬ã®èŸºãããªãã°ã©ããã§ããã, ãã®äœãæ¹ããæããã«, ãã(å³ 3.57ã®å®ç·)ãšå¥æ°çªç®ã®ç¹ã®æã€åœ¹å²ãšå¶æ°çªç®ã®ç¹ã®æã€åœ¹å²ã亀æããŠã§ãäžããã°ã©
ãã㯠52ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ã (å³ 3.57ã®ç Žç·å³)ã¯äºãã«å圢ãªã®ã§ (ãäºãã足ããšå®å šã°ã©ããã§ãäžãã), ãããã®ã°ã©ã (å³ 3.57ã®å®ç·, ç Žç·)ãäºãã«èªå·±è£å¯Ÿãšãªãããšã¯æããã§ãã.ï¿œ
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ããäŸé¡ 3.5 ã (2006幎床 æŒç¿åé¡ 3 )
å³ 3.58ã®ãããªå±éå³ãæ〠4ã€ã®ç«æ¹äœã®åé¡ã«ã¯è§£ãç¡ãããšã瀺ã.
G
G
Y
R
R B
B
R
G
G R Y
Y
Y
Y
R G B
B
B
B
Y G R
cube 1 cube 2
cube 3 cube 4
å³ 3.58: ããã§åé¡ã«ãã 4 ã€ã®ç«æ¹äœã®å±éå³.
(解çäŸ)
ãŸã, åç«æ¹äœã®å±éå³ã«ãããŠ, ãããçµã¿ç«ãŠããšãã«åããåãé¢ã©ããã蟺ã§çµãã§ã§ããã°ã©ãã¯ãããã次ã®å³ 3.59 (å·Š)ã®ããã«ãªã. åŸã£ãŠ, ãããã®ã°ã©ããäžã€ã®ã°ã©ãã«ãŸãšãããšå³ 3.59
R G
B Y
R
B
G
Y
R G
BY
R G
B Y
cube1 cube2
cube3 cube4
R G
BY
31
2
41
2
1
2
4
3
4 3
å³ 3.59: åå±éå³ããã§ããã°ã©ã (å·Š) ãš 4 ã€ã®ã°ã©ããäžã€ã«ãŸãšããŠã§ããã°ã©ã (å³).
(å³)ã®ããã«ãªã. ãã®ã°ã©ãã§èŸº RB,GYã¯å šãŠ cube4ããã®èŸºã§ãããã, å ±éãã蟺ãç¡ãæ¬¡æ° 2ã®æ£åã°ã©ãã¯éžã¹ãªãããšã«ãªã. ãã£ãŠ, äžãããã 4ã€ã®ç«æ¹äœãé¡æã®ããã«ç©ã¿äžããããšã¯ã§ããªã.
ãã㯠53ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäžï¿œ
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ããäŸé¡ 3.6 ã (2005幎床æ å ±å·¥åŠæŒç¿ II(B) #1)
åçŽã°ã©ã G ã®ç·ã°ã©ã L(G) (line graph)ãšã¯ Gã®å蟺ã«äžå¯Ÿäžå¯Ÿå¿ããç¹ãæã¡, Gã§é£æ¥ããŠãã 2æ¬ã®èŸºã«å¯Ÿå¿ãã L(G)ã® 2åã®ç¹ãå¿ ãçµãã§åŸãããã°ã©ãã®ããšã§ãã. ãã®ãšã以äžã®åãã«çãã.
(1) K3ãšK1,3ã®ç·ã°ã©ããããããæã, äž¡è ã¯åäžã®ã°ã©ããšãªãããšã瀺ã.(2)æ£åé¢äœã°ã©ãã®ç·ã°ã©ãã¯æ£å «é¢äœã°ã©ãã§ããããšã瀺ã.(3) Gãæ¬¡æ° kã®æ£åã°ã©ãã§ãããšã, L(G)ã¯æ¬¡æ° 2k â 2ã®æ£åã°ã©ãã§ããããšã瀺ã.(4) Gã®ç¹æ°ã§ãã£ãŠ, L(G)ã®èŸºæ°ãè¡šãå ¬åŒãäœã.(5) L(K5)ã¯ããŒã¿ãŒã¹ã³ã»ã°ã©ãã®æã°ã©ãã§ããããšã瀺ã.
(解çäŸ)
(1)å³ 3.60ãã, K3ãšK1,3 ã®ç·ã°ã©ãã¯åäžã§ãã.
å³ 3.60: K3 ã®ç·ã°ã©ã (å·Šã®å®ç·) ãš K1,3 ã®ç·ã°ã©ã.
(2)å³ 3.61åç §. åºæ¥äžããã°ã©ãã¯æ£å «é¢äœã°ã©ãã§ãã.
å³ 3.61: æ£åé¢äœã°ã©ã (K4) ã®ç·ã°ã©ã (å®ç·).
(3)æ¬¡æ° kã®æ£åã°ã©ãã®å蟺ã«ç¹ vi (i = 1, · · · ,m) (mã¯èŸºæ°)ãæã€. å蟺ã«é£æ¥ãã蟺æ°ã¯ (kâ1)ã§ãã,åç¹ viãšçµã¶ããšã®ã§ããä»ç¹ vj (j ï¿œ= i)ã®æ°ã¯ 2(kâ1)ã§ãã,ãããå šãŠã®ç¹ vi (i = 1, · · · ,m)ã«å¯ŸããŠåœãŠã¯ãŸãã®ã§, æ¬¡æ° kã®æ£åã°ã©ãã®ç·ã°ã©ãã¯æ¬¡æ° 2k â 2ã®æ£åã°ã©ãã§ããããšãããã.
(4)蟺æ°ãmã§è¡šããš (3)ã®çµæãšæ¡ææé¡ãã, 2(k â 1)à n = 2m, åŸã£ãŠ
m = n(k â 1) (3.67)
ãšãªã.
ãã㯠54ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
(5) (3)(4)ã®çµæãã, L(K5)ã®ç¹æ° n, 蟺æ°m, æ¬¡æ° d(æ£åã°ã©ãã§ããããšã«æ³šæ)ã¯
n(L(K5)) = m(K5) = 10, m(L(K5)) = n(k â 1) = 5Ã 3 = 15, d(L(K5)) = 2k â 2 = 6 (3.68)
ã§ãã. äžæ¹, 10åã®ç¹ãããªãå®å šã°ã©ãK10ã¯
n(K10) = 10, m(K10) = 45, d(K10) = 9 (3.69)
ã§ãã. é¡æãæ£ããã®ã§ããã°, ã€ãŸã, ãL(K5)ã¯ããŒã¿ãŒã¹ã³ã»ã°ã©ãã®æã°ã©ãã§ããããªãã°, æã°ã©ãã®å®çŸ©ãã, L(K5) +ããŒã¿ãŒãœã³ã»ã°ã©ã = K10ãšãªãã¹ãã§ããã, äžã®èå¯ãã,m(K10) âm(L(K5)) = 45 â 15 = 30 = m(ããŒã¿ãŒãœã³ã»ã°ã©ã), d(K10) âm(L(K5)) = 9 â 6 =3 = d(ããŒã¿ãŒãœã³ã»ã°ã©ã) ã§ãã, 確ãã«ããŒã¿ãŒãœã³ã»ã°ã©ãã§ããæ¡ä»¶ (ç¹æ° 10, èŸºæ° 30, æ¬¡æ° 3ã®æ£åã°ã©ã) ãæºãããŠãã. åŸã£ãŠ, L(K5)ã¯ããŒã¿ãŒã¹ã³ã»ã°ã©ãã®æã°ã©ãã§ãã.
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ããäŸé¡ 3.7 ã (2003幎床æ å ±å·¥åŠæŒç¿ II(B) #2)
ã°ã©ãG㯠2kåã®ç¹ãæã€åçŽã°ã©ãã§, äžè§åœ¢ã¯ç¡ããšãã. Gã®èŸºã®æ°m(2k)㯠k2以äžã§ãã
ããš, ã€ãŸã
m(2k) †k2 (3.70)
ã kã«é¢ããåž°çŽæ³ã§ç€ºã. ãŸã, ãã®èŸºã®æ°ã«ã€ããŠã®äžç k2 ãå®çŸããã°ã©ããäžã€äœã.
(解çäŸ)äžè§åœ¢ãå«ãŸãªãé£çµã°ã©ãã§èŸºã®æ°ãæ倧ã®ãã®ã¯å®å šäºéšã°ã©ãã§ãã.
ç¹ã«Kk,k ã¯èŸºã®æ° k2, ç¹ã®æ° 2kã§ãããã, ãã®Kk,k ã«å¯ŸããŠ
m(2k) †k2 (3.71)
ãä»®å®ã, Kk,k ã«ç¹ã 2〠(v,w)ã足ããŠ, 2k + 2åã®ç¹ããæãäžè§åœ¢ãæããªããããªã°ã©ããåºæ¥äžããããã« v, wãKk,kãçµã¶ãšãã®èŸºæ°ã®æ倧å€ã (k+ 1)2ãšãªãããšã瀺ãã°è¯ã (æ°åŠçåž°çŽæ³).ããã¯, å®å šäºéšã°ã©ãKk,k ã®é»äžžãš v(çœäžž)ãçµãã§ã§ãã kæ¬ãš, Kk,k ã®çœäžžãš w(é»äžž)ãçµãã§ã§
v
w
å³ 3.62: K3,3 ã«é¢ããäŸ. K3,3 ã«ç¹ v, w ãå ãã.
ãã kæ¬, ãããŠ, vãš wãçµãã§ã§ãã 1æ¬, ããã«, Kk,k ã«å ã ãã£ã k2 æ¬ã®æ¬æ°ã®èŸºããæãå®å š
äºéšã°ã©ãKk+1,k+1ã®å Žåã«èŸºæ°æ倧ã§ãã (å³ 3.62åç §), ãã®ãšãã®èŸºæ°ã¯ k2 + 2k+ 1 = (k+ 1)2ãš
ãã㯠55ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãªã. åŸã£ãŠ
m(2(k + 1)) †(k + 1)2 (3.72)
ãšãªã, æ°åŠçåž°çŽæ³ãã, Gã®èŸºæ°m(2k)㯠k2以äžã§ããããšã瀺ãã.ï¿œ
ᅵ
ᅵ
ᅵ
ããäŸé¡ 3.8ã (2007幎床 æŒç¿åé¡ 3 )
äŸé¡ 3.2ã§èŠãããã«, é£æ¥è¡åã® kä¹, ããªãã¡, Ak ã®ç¬¬ (i, j)æåã¯, ç¹ i, j ãçµã¶é·ã kã®æ©é
ã®æ¬æ°ã«çãã. ããããµãŸããŠ, ä»»æã®ã¹ã«ã©ãŒå€æ° x ã«å¯Ÿã, 次ã®è¡å:
I + xA + x2A2 + · · ·+ xkAk + · · · (3.73)
ãèããã (I ã¯åäœè¡å). æããã«, ãã®è¡å (3.73)ã®ç¬¬ (i, j)æåã xã®åªé¢æ°ãšã¿ãªãããšã,xk ã®ä¿æ°ã¯ç¹ i, jãçµã¶é·ã kã®æ©éã®æ¬æ°ãè¡šã. ããã§, ã¹ã«ã©ãŒ aã«å¯ŸããŠæ¬¡ã®ããŒã©ãŒå±é:
(1â a)â1 = 1 + a2 + a3 + · · ·+ ak + · · · (3.74)
ãæãç«ã£ãããšãæãåºãã°, è¡åAã«å¯ŸããŠãåæ§ã«
(I â xA)â1 = I + xA + x2A2 + · · ·+ xkAk + · · · (3.75)
ã®æç«ãæåŸ ã§ãã. ãã®ãšã, è¡å (I â xA)â1 ããæ©éçæè¡åããšåã¥ããããšã«ããã. ã€ãŸã, (3.75)åŒã®æç«ãã, è¡å (I â xA)â1 ã®ç¬¬ (i, j)æåã xã®åªé¢æ°ã§è¡šãããšã, xk ã®ä¿æ°ãèŠ
ããããã°, ç¹ i, jãçµã¶é·ã kã®æ©éã®æ¬æ°ãç¥ãããšãã§ãã. ãã®ãšã, å³ 3.63ã«äžãã 2ã€ã®ã°ã©ãã«å¯Ÿã, å ·äœçã«æ©éçæè¡å (I â xA)â1 ãæ±ã, å®éã«äžèšã®äºå®ã確ããã.
1 2
1
2
4
3
å³ 3.63: ããã§å ·äœçã«æ©éçæè¡åãæ±ãã 2 ã€ã®åçŽã°ã©ã.
(解çäŸ)
(1)ãŸãã¯, åé¡ã«äžããããå·ŠåŽã®ã°ã©ãã§ç°¡åã«é¡æã確ãããŠã¿ãã. å®çŸ©ãã, ãã®ã°ã©ãã®é£æ¥è¡åã¯æ¬¡ã® 2à 2ã®å¯Ÿç§°è¡åã§äžãããã.
A =
(0 11 0
). (3.76)
ãã£ãŠ
I â xA =
(1 00 1
)â x
(0 11 0
)=
(1 âxâx 1
)(3.77)
ãã㯠56ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãšãªããã, åé¡ã®æ©éçæè¡åã¯, ãã®éè¡åã§ãã
(I â xA)â1 =1
1â x2
(1 x
x 1
)=
(1
1âx2x
1âx2
x1âx2
11âx2
)(3.78)
ã§ãã. ããã§, ãã®è¡åã®åæåã xã®åªã§æžãçŽããŠã¿ããš
[(I â xA)â1]1,1 = 1 + x2 + x4 + · · ·+ x2n + · · · = [(I â xA)â1]2,2 (3.79)
[(I â xA)â1]1,2 = x+ x3 + x5 + · · ·+ x2n+1 + · · · = [(I â xA)â1]2,1 (3.80)
ã§ãã. ããã§, (1, 1)æåã¯ç¹ 1ããåºçºããŠ, ç¹ 1ãžãšæ»ãæ©éã§ãããã, ãã®ãããªæ©éã®é·ãkã¯å¿ ãå¶æ°ã§ãªããã°ãªãã, å kã«å¯ŸããŠåã 1ã€ã®æ©éãååšãã. ããã, (3.79)åŒã® xã®åª
ã«å¶æ°æ¬¡ã®ã¿ãçŸã, ãã®ä¿æ°ãå šãŠ 1ã§ããããšã«åæ ããŠãã.äžæ¹ã® (1, 2)æåã¯ç¹ 1ããç¹ 2ãžè³ãæ©éã§ãããã, ãã®ãããªæ©éã®é·ã kã¯å¿ ãå¥æ°ã§ãªãã
ã°ãªããªã, å kã«å¯ŸããŠåã 1ã€ã®æ©éãååšãã. ããã, (3.80)åŒã® xã®åªã«å¥æ°æ¬¡ã®ã¿ãçŸã,ãã®ä¿æ°ãå šãŠ 1ã§ããããšã«åæ ããŠãã. 以äžã®èå¯ãã, 確ãã«ãã®ã°ã©ãã«å¯Ÿã, æ©éçæã®è¡åèŠçŽ ã¯é¡æãæºãããŠããããšãããã.
(2) (1)ãšåæ§ã«é£æ¥è¡åãæ±ããŠã¿ããš, 次㮠4à 4ã®å¯Ÿç§°è¡å:
A =
ââââââ
0 1 0 11 0 1 10 1 0 01 1 0 0
ââââââ (3.81)
ãšãªã. ãã£ãŠ
I â xA =
ââââââ
1 âx 0 âxâx 1 âx âx0 âx 1 0âx âx 0 1
ââââââ (3.82)
ã§ãã. ããã§, ãã®éè¡åã§ããæ©éçæè¡åãæ±ããã.ãŸãã¯è¡ååŒãæ±ããã. 第 4åç®ã§äœå åå±éãããš, 次ã®è¡ååŒ:
det(I â xA) = x
â£â£â£â£â£â£â£âx 1 âx0 âx 1âx âx 0
â£â£â£â£â£â£â£â xâ£â£â£â£â£â£â£
1 âx 00 âx 1âx âx 0
â£â£â£â£â£â£â£ +
â£â£â£â£â£â£â£1 âx 0âx 1 âx0 âx 1
â£â£â£â£â£â£â£= x
{âx
â£â£â£â£â£ âx 1âx 0
â£â£â£â£â£â xâ£â£â£â£â£ 1 âxâx 1
â£â£â£â£â£}â x
{â£â£â£â£â£ âx 1âx 0
â£â£â£â£â£â xâ£â£â£â£â£ âx 0âx 1
â£â£â£â£â£}
+
{â£â£â£â£â£ 1 âxâx 1
â£â£â£â£â£ + x
â£â£â£â£â£ âx 0âx 1
â£â£â£â£â£}
= x(âx2 â x+ x3)â x(x+ x2) + 1â 2x2 = 1â 4x2 â 2x3 + x4 (3.83)
ãåŸããã. åŸã£ãŠ, éè¡åã®æåã aij ãè¡å I â xA ã®ç¬¬ (i, j)äœå åè¡åãšããŠ
[(I â xA)â1]ij = {det(I â xA)}â1(â1)i+j aij (3.84)
ãšæžããããšã«æ³šæãããš, åäœå åè¡å aij ãå ·äœçã«
a1,1 =
â£â£â£â£â£â£â£1 âx âxâx 1 0âx 0 1
â£â£â£â£â£â£â£ = âxâ£â£â£â£â£ âx 1âx 0
â£â£â£â£â£ +
â£â£â£â£â£ 1 âxâx 1
â£â£â£â£â£ = 1â 2x2
ãã㯠57ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
a1,2 =
â£â£â£â£â£â£â£âx âx âx0 1 0âx 0 1
â£â£â£â£â£â£â£ = âxâ£â£â£â£â£ 1 0
0 1
â£â£â£â£â£â xâ£â£â£â£â£ âx âx
1 0
â£â£â£â£â£ = âxâ x2 = a2,1
a1,3 =
â£â£â£â£â£â£â£âx 1 âx0 âx 0âx âx 1
â£â£â£â£â£â£â£â xâ£â£â£â£â£ âx 0âx 1
â£â£â£â£â£â xâ£â£â£â£â£ 1 âxâx 0
â£â£â£â£â£ = x3 + x2 = a3,1
a1,4 =
â£â£â£â£â£â£â£âx 1 âx0 âx 1âx âx 0
â£â£â£â£â£â£â£ = âxâ£â£â£â£â£ âx 1âx 0
â£â£â£â£â£â xâ£â£â£â£â£ 1 âxâx 1
â£â£â£â£â£ = x3 â x2 â x = a4,1
a2,2 =
â£â£â£â£â£â£â£1 0 âx0 1 0âx 0 1
â£â£â£â£â£â£â£ =
â£â£â£â£â£ 1 00 1
â£â£â£â£â£â xâ£â£â£â£â£ 0 âx
1 0
â£â£â£â£â£ = 1â x2
a2,3 =
â£â£â£â£â£â£â£1 âx âx0 âx 0âx âx 1
â£â£â£â£â£â£â£ =
â£â£â£â£â£ âx 1âx 0
â£â£â£â£â£â xâ£â£â£â£â£ âx 0âx 0
â£â£â£â£â£ = x3 â x = a3,2
a2,4 =
â£â£â£â£â£â£â£1 âx 00 âx 1âx âx 0
â£â£â£â£â£â£â£ =
â£â£â£â£â£ âx 1âx 0
â£â£â£â£â£â xâ£â£â£â£â£ âx 0âx 1
â£â£â£â£â£ = x2 + x = a4,2
a3,3 =
â£â£â£â£â£â£â£1 âx âxâx 1 âxâx âx 1
â£â£â£â£â£â£â£ =
â£â£â£â£â£ 1 âxâx 1
â£â£â£â£â£ + x
â£â£â£â£â£ âx âxâx 1
â£â£â£â£â£â xâ£â£â£â£â£ âx âx
1 âx
â£â£â£â£â£ = 1â 3x2 â 2x3
a3,4 =
â£â£â£â£â£â£â£1 âx 0âx 1 âxâx âx 0
â£â£â£â£â£â£â£ =
â£â£â£â£â£ 1 âxâx 0
â£â£â£â£â£ + x
â£â£â£â£â£ âx âxâx 0
â£â£â£â£â£ = âx3 â x2 = a4,3
a4,4 =
â£â£â£â£â£â£â£1 âx 0âx 1 âx0 âx 1
â£â£â£â£â£â£â£ =
â£â£â£â£â£ 1 âxâx 1
â£â£â£â£â£ + x
â£â£â£â£â£ âx 0âx 1
â£â£â£â£â£ = 1â 2x2
ã§äžããããã®ã§, æ±ããéè¡åã¯å¯Ÿç§°è¡åã§ãã, (3.84)åŒãã ai,j ã« (â1)i+j ã®ãã¡ã¯ã¿ãä»ãã
ãšã«æ³šæã㊠((1, 1)æåãªãã°, (â1)1+1 = 1, (1, 2)æåã§ããã°, (â1)1+2 = â1ã®ããã«ãã¡ã¯ã¿ãããã)
(I â xA)â1 =
ââââââ
1â2x2
1â4x2â2x3+x4x2+x
1â4x2â2x3+x4x3+x2
1â4x2â2x3+x4x+x2âx3
1â4x2â2x3+x4
x2+x1â4x2â2x3+x4
1âx2
1â4x2â2x3+x4xâx3
1â4x2â2x3+x4x2+x
1â4x2â2x3+x4
x3+x2
1â4x2â2x3+x4xâx3
1â4x2â2x3+x41â3x2â2x3
1â4x2â2x3+x4x3+x2
1â4x2â2x3+x4
xâx2âx3
1â4x2â2x3+x4x2+x
1â4x2â2x3+x4x3+x2
1â4x2â2x3+x41â2x2
1â4x2â2x3+x4
ââââââ (3.85)
ãåŸããã. ããã§, åé¡ãšããã°ã©ãã®å¯Ÿç§°æ§ãã, (1, 2)æåãš (2, 4)æå, (1, 1)æåãš (4, 4)æåãªã©ãçãããªãããšã«æ³šæããã.ããŠ, ããã§åæåã xã®åªã§å±éããŠã¿ãŠ, å®éã«é¡æãæºããããããšã確èªããŠã¿ãã. ãŸãã¯,æ©éçæè¡åã® (1, 1)æåã«ã€ããŠå€æ° xã§å±éãããš
[(I â xA)â1]1,1 (1â 2x2){1 + (4x2 + 2x3 â x4) + (4x2 + 2x3 â x4)2 + · · ·}= 1 + (4x2 â 2x2) + 2x3 + (â8x4 â x4 + 16x4) +O(x5)
= x0 + 2x2 + 2x3 + 7x4 +O(x5) (3.86)
ãã㯠58ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãåŸããã. ããã§, O(xα)㯠xα 以äžã®åªãè¡šããã®ãšå®çŸ©ãã. åŸã£ãŠ, ç¹ 1ããç¹ 1ãžæ»ã£ãŠããé·ã 2ã®æ©éæ°ã¯ 2, é·ã 3ã®æ©éæ°ã 2ã§ãã, å³ 3.64ã®ããã«ç¢ºãã«ããã ãã®å Žåã®æ°ãããããšã確ããããã. é·ã 4ã®æ©éæ°ã¯æ©éçæè¡åã®æ¹æ³ãã㯠7ãšèŠç©ããããã, å®éã«ã°ã©ã
1
2 3
4
1
2 3
4
1
2
12
1
23
4
1
23
4
1
2
31
2
3
å³ 3.64: äžããããã°ã©ãã®ç¹ 1 ããç¹ 1 ãžãšæ»ãé·ã 2 ã®æ©é (å·Š) ãšé·ã 3 ã®æ©é (å³).
ããèŠã€ãåºããŠã¿ããš
1â 2â 1â 2â 1, 1â 4â 1â 4â 1, 1â 2â 4â 2â 1
1â 4â 2â 4â 1, 1â 4â 1â 2â 1, 1â 2â 1â 4â 1
1â 2â 3â 2â 1
ã® 7æ¬ãååšããããšãããã (â» ãã®ãããªè¡šèšã§ã¯ç¢å°ã®æ¬æ°ãæ©éã®æ¬æ°ã«ãªãããšã«æ³šæ).åŸã£ãŠ, 確ãã«é¡æãæºãããŠãã.次ã«, (1, 2)æåãèããŠã¿ãã. æ©éçæè¡åã®ãã®æåã¯å€æ° xã§å±éããŠ
[(I â xA)â1]1,2 (x2 + x){1 + (4x2 + 2x3 â x4) + (4x2 + 2x3 â x4)2 + · · ·}= x+ x2 + 4x3 + (4x4 + 2x4) +O(x5)
= x+ x2 + 4x3 + 6x4 +O(x5) (3.87)
ãšãªã. ç¹ 1ããç¹ 2ãžè³ãé·ã 1ã®æ©éã¯æããã« 1æ¬. é·ã 2ã®æ©é㯠1â 4â 2ã®ã¿ã§ãã, ããã 1æ¬. é·ã 3ã®æ©éã¯å³ 3.65ã«ç€ºãã 4æ¬ã§ãã, 確ãã«ãã®æ¬æ°ã¯æ©éçæè¡åã®äžããæ¬æ°ãšäžèŽããŠãã. ãŸã, é·ã 4ã®æ©éãã°ã©ãããæ¢ããŠã¿ããš
1
23
4
1
23
4
1
2 3
4
1
23
4
1
2
3
1
2
3
12
3
12
3
å³ 3.65: äžããããã°ã©ãã®ç¹ 1 ããç¹ 2 ãžãšæ»ãé·ã 3 ã®æ©é.
1â 2â 4â 1â 2, 1â 4â 1â 4â 2, 1â 4â 2â 3â 2
1â 2â 1â 3â 2, 1â 4â 2â 4â 2, 1â 4â 2â 1â 2
ãšãªã, ããã確ãã«æ©éçæè¡åã®ç¬¬ (1, 2)æåã® x4ã®å±éä¿æ°ãšäžèŽããŠãã. åŸã£ãŠ, ãã®å Žåãé¡æãæºãããŠãã.
ãã㯠59ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
次㫠(1, 3)æåãèãã. æ©éçæè¡åã®ãã®æåã¯å€æ° xã§å±éããããšã«ãã
[(I â xA)â1]1,3 (x3 + x2){1 + (4x2 + 2x3 â x4) + (4x2 + 2x3 â x4)2 + · · ·}= x2 + x3 + 4x4 +O(x5) (3.88)
ãšãªã. ã°ã©ããã, ç¹ 1ãšç¹ 3ãçµã¶é·ã 2ã®æ©é㯠1â 2â 3ã® 1æ¬. é·ã 3ã®æ©éã 1â 4â2â 3ã® 1æ¬ã®ã¿. ããã«, é·ã 4ã®æ©éãã°ã©ãããæ¢ããŠã¿ããš
1â 2â 1â 2â 3, 1â 2â 4â 2â 3, 1â 4â 1â 2â 3, 1â 2â 3â 2â 3
4æ¬ãååšãã. åŸã£ãŠ, ãã®å Žåã, æ©éã®æ°ãšæ©éçæè¡åã®åé ã®ä¿æ°éã®é¢ä¿ã¯æç«ããŠãã.次㫠(1, 4)æåã¯å€æ° xã§å±éããŠ
[(I â xA)â1]1,4 (x+ x2 â x3){1 + (4x2 + 2x3 â x4) + (4x2 + 2x3 â x4)2 + · · ·}= x+ x2 + (âx3 + 4x3) + (4x4 + 2x4) +O(x5)
= x+ x2 + 3x3 + 6x4 +O(x5) (3.89)
ãšãªã. ç¹ 1ãšç¹ 4ãçµã¶é·ã 1ã®æ©éã¯æããã« 1æ¬. é·ã 2ã®æ©é㯠1 â 4 â 2ã® 1æ¬. é·ã 3ã®æ©é㯠1â 4â 1â 4, 1â 4â 2â 4, 1â 2â 1â 4ã® 3æ¬ãã. é·ã 4ã®æ©éã¯
1â 4â 2â 1â 4, 1â 2â 3â 2â 4, 1â 4â 1â 2â 4
1â 2â 1â 2â 4, 1â 2â 1â 1â 4, 1â 2â 4â 2â 4
ã® 6æ¬ã§ãã, ãããã¯ããããæ©éçæè¡åã®åé ã®ä¿æ°ãšäžèŽãã.æåŸã«æ©éçæè¡åã® (2, 2)æåã確ãããŠããã. ãã®æåãå€æ° xã® 4次ãŸã§æžãåºããŠã¿ããš
[(I â xA)â1]2,2 (1â x2){1 + (4x2 + 2x3 â x4) + (4x2 + 2x3 â x4)2 + · · ·}= 1 + (4x2 â x2) + 2x3 + (â4x4 â x4 + 16x4) +O(x5)
= x0 + 3x2 + 2x3 + 11x4 +O(x5) (3.90)
ãåŸããã. åŸã£ãŠ, ç¹ 2ããç¹ 2ãžãšæ»ãé·ã 2ã®æ©é㯠2â 1â 2, 2â 4â 2, 2â 3â 2ã® 3æ¬, é·ã 3ã®æ©é㯠2â 1â 4â 2, 2â 4â 1â 2ã® 2éã. é·ã 4ã®æ©éã¯å°ã å€ããã°ã©ãããèŠã€ããŠæžãåºããŠã¿ããš
2â 1â 2â 1â 2, 2â 4â 2â 4â 2, 2â 3â 2â 3â 2
2â 1â 4â 1â 2, 2â 4â 1â 4â 2, 2â 1â 2â 3â 2
2â 4â 2â 3â 2, 2â 1â 2â 4â 2, 2â 4â 2â 1â 2
2â 3â 2â 4â 2, 2â 3â 2â 1â 2
ã® 11éããã. åŸã£ãŠ, ãã®æåã®å Žåãæ©éæ°ãšå±éä¿æ°ãšã®éã®é¢ä¿ã¯æç«ããŠãã, é¡æãæºãããŠãã.åèã®ãã, åæåã xã® 4次ã®é ãŸã§æžãäžããŠæ©éçæè¡åãæžãçŽãããã®ãèŒããŠããã.
(I â xA)â1x ã® 4 次ãŸã§
=
ââââââ
1 + 2x2 + 2x3 + 7x4 x+ x2 + 4x3 + 6x4 x2 + x3 + 4x4 x+ x2 + 3x3 + 6x4
x+ x2 + 4x3 + 6x4 1 + 3x2 + 2x3 + 11x4 x+ 3x3 + 2x4 x+ x2 + 4x3 + 6x4
x2 + x3 + 4x4 x+ 3x3 + 2x4 1 + x2 + 3x4 x2 + x3 + 4x4
x+ x2 + 3x3 + 6x4 x+ x2 + 4x3 + 6x4 x2 + x3 + 4x4 1 + 2x2 + 2x3 + 7x4
ââââââ
(3.91)
ãã㯠60ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãã®æŒç¿åé¡ã§èŠãããã«, æ©éã®é·ããé·ããªãã°ãªãã»ã©, ã°ã©ãã«ååšããæ©éã®èšæ°ã«å¯Ÿã,æ©éçæè¡åã®æ¹æ³ãåšåãçºæ®ããããã«ãªã.
â»æ³šæ: æ°åŠçã«ã¿ããš, ååã®é åžè³æ (24)åŒã察称ã§ããé£æ¥è¡åã«å¯ŸããŠäžè¬ã«æç«ããããšãããã£ã段éã§, ãããåå¥ã®åçŽã°ã©ãã«å¯ŸããŠãæãç«ã€ã®ã¯æããã§ãã. ããã, å®éã«æ©éãæ°ãäžããå Žåã«ã¯, ãã®æŒç¿ã§ã¿ãããã«æ©éçæè¡åã®åæåãåå¥ã®ã°ã©ãã«å¯ŸããŠå ·äœçã«èšç®ããªããã°ãªããªã. ç¹ã«éã®ããé·ãæ©éãæ°ãäžããå Žåã«ã¯å€æ° xã«ã€ããŠã®é«æ¬¡ã®
å±éä¿æ°ãå¿ èŠã«ãªãã, ããã§ã¿ãããã«, ãã®ä¿æ°ãæ±ããããšã¯ã°ã©ãäžã§å®éã«å¯èœãªéãæ°ãäžããŠãããã容æãªäœæ¥ã§ãã.
ãã㯠61ããŒãžç®
63
第4åè¬çŸ©
4.1 éãšéè·¯
ããã§ã¯, ãéãåã³ãéè·¯ãã«é¢ã, ãã®æŠå¿µã»è«žå®ç, åã³, å¿çšäŸãå ·äœäŸããããŠèª¬æãã.
4.1.1 é£çµæ§
é£çµ : ã°ã©ãã®å 2ç¹ã®éã«éããã.
æ©é : vi (i = 1, · · · ,m) â Gã«å¯Ÿã, 蟺å v0v1, v1v2, · · · , vmâ1vm ãæ©é (walk) ãšãã.â å¥ã®è¡šçŸ : v0 â v1 â v2 â · · · â vm (v0 : å§ç¹, vm : çµç¹)
å°é : å šãŠã®èŸº v0v1, · · · , vmâ1vm ãç°ãªãæ©é
é : ç¹ v0, v1, · · · , vm ãå šãŠç°ãªãæ©é (â» v0 = vm ã§ãã£ãŠãè¯ããšãã)éè·¯ : å°ãªããšã 1æ¬èŸºãæã€éããé
v
w
y
x
z
å³ 4.66: ãã®ã°ã©ãã«ãããŠ, é路㯠x â v â w â xï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 4.1ã (2003幎床 ã¬ããŒãèª²é¡ #3 åé¡ 1 )
é£çµåçŽã°ã©ã Gã®ç¹éå㯠{v1, v2, · · · , vn} ã§ãã, mæ¬ã®èŸºããã³ tåã®äžè§åœ¢ããããšãã. 以äžã® (1)ïœ(3)ã«çãã.
(1) Gã®é£æ¥è¡åãAãšãããš, è¡åA2 ã® ij èŠçŽ 㯠vi ãš vj éã®é·ã 2ã®æ©éã®åæ°ã«çããããšã瀺ã.
(2)è¡åA2ã®å¯Ÿè§èŠçŽ ã®ç·å㯠2mã§ããããšã瀺ã.(3)è¡åA3ã®å¯Ÿè§èŠçŽ ã®ç·å㯠6tã§ããããšã瀺ã.
(解çäŸ)
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
(1)ããã¯ååã®äŸé¡ 3.8ã®åŸ©ç¿ã§ããã. é£çµã°ã©ã Gã«é¢ãã nà nã®é£æ¥è¡åã
A =
âââ
a11 · · · a1n
· · · · · · · · ·an1 · · · ann
âââ (4.92)
ãšçœ®ããšé£æ¥è¡åã®èªä¹A2ã¯
A2 =
âââ
ânk=1 a1kak1 · · · ân
k=1 a1kakn
· · · · · · · · ·ânk=1 ankak1 · · · ân
k=1 ankakn
âââ â¡
âââ
b11 · · · b1n
· · · · · · · · ·bn1 · · · bnn
âââ â¡ B (4.93)
ãšæžã, A2 ã® ij èŠçŽ ã§ãã bij ã¯
bij =nâ
k=1
aikakj (4.94)
ã§ãã. ãšããã§, é£æ¥è¡åã®å®çŸ©ãã aik ã¯ç¹ viãšç¹ vk ãçµã¶èŸºã®æ¬æ°, akj ã¯ç¹ vk ãšç¹ vj ãçµã¶
蟺ã®æ¬æ°ã§ãããã, ç© aikakj ã¯ç¹ viããç¹ vk ãçµç±ããŠç¹ vj ã«è³ãé·ã 2ã®æ©éã®æ°ã«çžåœãã(å³ 4.67åç §). çµç±ç¹ vk (k = 1, · · · , n) ã®éžã³æ¹ã®å¯èœæ§ (i = k, j = k ã®å Žåã«ã¯ãã«ãŒããããã
...
v
v
vi
k
j
å³ 4.67: ç¹ vk ã¯ç¹ vi ããç¹ vj ãžè³ãçµç±ç¹.
ãšèãã) ã«é¢ã, ãã®ç© aikakj ã足ãäžãã
nâk=1
aikakj = bij (4.95)
㯠viãã vj ãžè³ãé·ã 2ã®æ©éã®æ°ã§ãã. ããªãã¡, A2ã® ijèŠçŽ bij 㯠viãã vj ãžè³ãé·ã 2ã®æ©éã®æ°ã«çãã.
(2) (1) ã®çµæãèæ ®ãããš, è¡åB = A2ã®å¯Ÿè§æå
bii =nâ
k=1
aikaki (4.96)
ã¯ç¹ vi ããç¹ vk ãçµç±ã㊠vi ãžæ»ãé·ã 2ã®æ©éã®æ°ã§ãããã, ãã㯠vi ãš vk ãçµã¶èŸºã®æ°ã®
2åã«ãªã£ãŠãã (å³ 4.68åç §). åŸã£ãŠ, è¡åA2 ã®å¯Ÿè§å
nâi=1
bii =nâ
i=1
nâk=1
aikaki (4.97)
ã¯é£çµã°ã©ã Gã«å«ãŸãã蟺ã®æ¬æ°ã® 2å, ããªãã¡ 2mã§ãã.
ãã㯠64ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
v
v
i
k
å³ 4.68: äžç¶ç¹ vk ãçµãŠ, vi ãžæ»ãçµè·¯.
(3) A3 ãèšç®ãããš
A3 =
âââ
ânk=1
ânl=1 a1kaklal1 · · · ân
k=1
ânl=1 a1kaklaln
· · · · · · · · ·ânk=1
ânl=1 ankaklal1 · · · ân
k=1
ânl=1 ankaklaln
âââ â¡
âââ
c11 · · · c1n
· · · · · · · · ·cn1 · · · cnn
âââ = C (4.98)
ã§ãããã, A3ã® ij æåã¯
cij =nâ
k=1
nâl=1
aikaklalj (4.99)
ãšæžãã.ãšããã§, é£æ¥è¡åã®å®çŸ©ãã aik ã¯ç¹ viãšç¹ vk éã®èŸºã®æ¬æ°, aklã¯ç¹ vk ãšç¹ vl éã®èŸºã®æ¬æ°, alj
ã¯ç¹ vl ãšç¹ vj éã®èŸºã®æ¬æ°ã§ãããã, ãããã®ç© aikaklalj ã¯ç¹ vi ããç¹ vk åã³ç¹ vl ãçµç±ããŠ
ç¹ vj ãžè³ãæ©éã®æ°ã§ãã. åŸã£ãŠ, çµç±ç¹ {vk, vl} ã®å¯èœæ§ã«ã€ããŠè¶³ãåãããnâ
k=1
nâk=1
aikaklalj = cij (4.100)
ã€ãŸã, è¡åA3ã® ij èŠçŽ ã¯ç¹ vi ããç¹ vj ãžè³ãé·ã 3ã®æ©éã®æ°ã«çãã (å³ 4.69åç §). ãŸã,
v
vv
vi
kl
j
å³ 4.69: ç¹ vi ããçµç±ç¹ {vk , vl} ãçµãŠ vj ãžãšè³ãçµè·¯.
cii =nâ
k=1
nâl=1
aikaklali (4.101)
ã¯ç¹ viããç¹ vk åã³ç¹ vl ãçµç±ã㊠viãžè³ãé·ã 3ã®éè·¯ã®æ°ã§ãããã. ããã¯ç¹ vi, vk åã³ç¹
vl ãçµã¶äžè§åœ¢ã®æ°ã§ãã. åŸã£ãŠ, ãããçµç±ç¹ {vk, vl}ã®å¯èœæ§ã«ã€ããŠè¶³ãäžããnâ
i=1
cii =nâ
i=1
nâk=1
nâl=1
aikaklali (4.102)
ã¯é£çµã°ã©ãGã«å«ãŸããäžè§åœ¢ã®åæ°ã® 6å (i, k, lã®äžŠã¹æ¹ 3 ! = 6éãã«çž®é) ã«çãã (å³ 4.70åç §). ããªãã¡
ãã㯠65ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
v
v
vi
k
l
å³ 4.70: ç¹ vi ãåºçºã, ç¹ {vk , vl} ãçµãŠç¹ vi ãžãšæ»ãéè·¯ã¯äžè§åœ¢ã圢æãã.
nâi=1
cii = 6t (4.103)
ã«çãã.
å®ç 5.2ã°ã©ã G 㯠nåã®ç¹ãæã€åçŽã°ã©ãã§ãããšãã. Gã«ã¯ kåã®æåããããšã, Gã®èŸºã®æ¬æ°mã¯æ¬¡åŒãæºãã.
nâ k †m †12(nâ k)(nâ k + 1) (4.104)
(蚌æ)ãŸã, (4.104)ã«ãããäžçãè¡šãäžçåŒ : m ⥠n â k ã«ã€ããŠç€ºã. 空ã°ã©ã m = 0ã®ãšãã¯èªæã§ãã, n = kãã, 0 †0â 0 = 0ã§æç«ãã. åŸã£ãŠ, 以äžã§ã¯ãã®å Žåãé€å€ããŠèãã. æ¹éãšããŠã¯, 蟺æ°ãm0 â 1ã®ãšãã«äžçåŒã®æç«ãä»®å®ã, m0ã®ãšãã®æç«ã瀺ããšããæ°åŠçåž°çŽæ³ã«ãã蚌æãã
ããšã«ããã.ãã®ããã«, åçŽã°ã©ã Gããä»»æã®èŸºã 1æ¬åé€ããå Žå, æåæ°, ç¹æ°, 蟺æ°ã¯ã©ã®ããã«å€åããã®ããèå¯ãããš
æåæ° : k â k + 1
ç¹æ° : n â n
èŸºæ° : m0 â m0 â 1
ãšãªããã, äžã®ç¢å°ã®å³åŽã®ããããã®é (k + 1, n,m0 â 1)ã«é¢ããŠäžçåŒãäœããš
m0 â 1 ⥠nâ (k â 1)
ãæç«ãã. åŸã£ãŠ, ãã®èŸºæ°m0 â 1ã«é¢ããäžçåŒã®æç«ãä»®å®ã, ãããã蟺æ°m0 ã«ã€ããŠã®äžç
åŒã®æç«ãå°ãã°ããããã§ããã, ããã¯äžäžçåŒãæžãçŽãã°çŽã¡ã«
m0 ⥠nâ kãåŸãããã®ã§, åž°çŽæ³ã«ãã, å šãŠã®mã«å¯ŸããŠäžçåŒ : m ⥠nâ kã®æç«ã瀺ããã.
次ã«, (4.104)ã®äžçã瀺ãäžçåŒ : m †(nâ k)(nâ k + 1)/2ã«ã€ããŠã®æç«ã瀺ã. 蟺ã®æ°ã®äžçãèããããã§ãããã, ã°ã©ãGãæåæ°ã kã®ã°ã©ãã§, 蟺ã®æ°ãäžçªå€ããã®ãšããã°, ãã®ã°ã©ãGã®åæåã¯å®å šã°ã©ãã§ãããšããŠãã. ããã§, ãã®æåã®äžã§ä»»æã® 2æå Ci,Cj ãéžã³, Ciã«ã¯ niå,Cj ã«ã¯ nj åã®ç¹ããã£ããšãã (ni ⥠nj). ã€ãŸã, Ci + Cj ã®èŸºã®ç·æ°Nij ã¯ãããããå®å šã°ã©ãã§
ããããšãèæ ®ãããš (å³ 4.71ãåç §).
Nij =12ni(ni â 1) +
12nj(nj â 1) (4.105)
ãã㯠66ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
Ci
Cjn i
n j
n i +1
n j -1
C
C
i
j
å³ 4.71: å®å šã°ã©ã Ci ã«ç¹ãäžã€è¶³ããŠå®å šã°ã©ããäœã, å®å šã°ã©ã Cj ããç¹ãäžã€åŒã, å®å šã°ã©ããäœã.
ãšãªã. ããŠ, ããã§æ¬¡ã®æäœãèãã.
(æäœ)
Ci â ni + 1åã®ç¹ãæã€å®å šã°ã©ããCj â nj â 1åã®ç¹ãæã€å®å šã°ã©ã
ãã®çœ®ãæãã«ãã, Ci + Cj ã®ç¹æ°ã¯äžå€ã§ããã, 蟺æ°N â²ij ã¯
N â²ij =
12ni(ni + 1) +
12(nj â 1)(nj â 2) (4.106)
ã®ããã«å€åãã. åŸã£ãŠ, ãã® (æäœ)ã«ãã, 蟺ã®æ°ã¯
ÎNij = N â²ij âNij
=12ni(ni + 1) +
12(nj â 1)(nj â 2)â
{12ni(ni â 1) +
12nj(nj + 1)
}= ni â nj + 1 > 0(4.107)
ã ãå¢å ãã.ãã®è°è«ãé²ãããš, çµå±, æåæ°ã kã§ããã°ã©ãã§æã蟺æ°ãå€ãã°ã©ãGã¯ç¹ã®æ°ã nâ (kâ1) =
nâ k + 1åã®å®å šã°ã©ããš k â 1åã®å€ç«ç¹ (空ã°ã©ã)ãããªãã°ã©ãã§ãããšçµè«ä»ããããã®ã§, 蟺æ°mã®äžéã¯äžçåŒ:
m †12(nâ k)(nâ k + 1) (4.108)
ãæºããããšãããã (蚌æçµãã).
ãã㯠67ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäžï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 4.2 ã (2003幎床 æ å ±å·¥åŠæŒç¿ II(B) #2)
é£çµã°ã©ãã«ãããŠ, ç¹ vãã wãžã®è·é¢ d(v,w)㯠vãã wãžã®æçè·¯ã®é·ãã§ãã. ãã®ãšã, 以äžã®åã (1)(2)ã«çãã.
(1) d(v,w) ⥠2ãªãã°
d(v, z) + d(z, w) = d(v,w) (4.109)
ãªãç¹ zãååšããããšã瀺ã.(2)ããŒã¿ãŒã¹ã³ã»ã°ã©ãã«ãããŠ, ä»»æã®ç°ãªã 2ç¹ vãš wã«å¯Ÿã㊠d(v,w) = 1ãŸã㯠d(v,w) = 2ã§ããããšã瀺ã.
(解çäŸ)
(1)å³ 4.72ã®ãããªç¶æ³ãèãã. ç¹ vãã wãžã®æçè·¯ã C ãšãã. C ã®å šé·ã¯ d(v,w)ã§ãã. ãã®
v
zw
C
C
1
2
C
C
1
2
*
*
å³ 4.72: v â z â w ã®çµè·¯ C = C1 + C2 㯠v ãã w ãžã®æçè·¯ã§ãã, ãã®é·ã㯠d(v, w) ã§äžãããã.
çµè·¯ C äžã«ä»»æã®ç¹ zããšã, ãã®ç¹ zãäžç¶ç¹ãšããŠçµè·¯ C ã 2ã€ã®éšåã«åããŠ, éšåè·¯ v â z
ã C1, éšåè·¯ z â wã C2 ãšãã.ãã®ç¹ zã«å¯Ÿã, C1 㯠vãš z ãçµã¶å šãŠã®çµè·¯ã®ãã¡ã§æçè·¯ã§ãã. ãªããªãã°, ãã vãš z ãçµ
ã¶å¥ã®çµè·¯ã®äžã§ C1ãããçããã®ãååšãããšããã°, ãã®çµè·¯ C1â ãš C2 ãåãããæ°ããçµè·¯
C1â +C2ã vãš wãçµã¶å šãŠã®çµè·¯ã®äžã§æçãšãªã, ä»®å®ã«åãã. åŸã£ãŠ, çµè·¯ C1ãç¹ vãš zã
çµã¶å šãŠã®çµè·¯ã®äžã§æçã§ãã, C1ã®å šé·ã d(v, z)ã§ãã.次ã«, z ãš wãçµã¶çµè·¯ã®äžã§æçã®ãã®ã§ããã, ããã C2 ã§ããããšã¯æããã§ãã. ãªããªãã°, ãã®çµè·¯ãšå¥ãªçµè·¯ C2â ãååšãããšããã°, C1ãš C2â ã足ãåãããçµè·¯ C1 +C2â ã vãš wã
çµã¶å šçµè·¯ã®äžã§æçãšãªã, ä»®å®ã«åãã. åŸã£ãŠ, C2ã zãš wãçµã¶å šçµè·¯ã®ãã¡ã§æçã§ãã,ãã®å šé·ã¯ d(z, w)ã§ãã. åŸã£ãŠ, èããã°ã©ãã¯é£çµã§ãããã, çµè·¯ C äžã«äžç¶ç¹ zããã€ã§ã
ä»»æã«ãšãããšãã§ã, ãã®ç¹ zã«å¯ŸããŠ
d(v, z) + d(z, w) = d(v,w) (4.110)
ãæãç«ã€.
(2)å³ 4.73ã®ããã«, ããŒã¿ãŒã¹ã³ã»ã°ã©ãã®åç¹ã«çªå·ãä»ãã. ããŒã¿ãŒã¹ã³ã»ã°ã©ãã®å¯Ÿç§°æ§ãã,ç¹ 1, 6 ãã¹ã¿ãŒãå°ç¹ã«éžãã å Žåã®åä»ç¹ãžã®æçè·¯ãèããã°ååã§ãã (æ¬åŒ§å ã¯é·ã dãäž
ããçµè·¯).
d(1, 2) = 1 (1â 2), d(1, 3) = 2 (1â 2â 3), d(1, 4) = 2 (1â 5â 4)
d(1, 5) = 1 (1â 5), d(1, 6) = 1 (1â 6), d(1, 7) = 2 (1â 2â 7),
d(1, 8) = 2 (1â 6â 8), d(1, 9) = 2 (1â 6â 9), d(1, 10) = 2 (1â 5â 10)
ãã㯠68ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
1
2
3 4
5
6
7
8 9
10
å³ 4.73: ããŒã¿ãŒã¹ã³ã»ã°ã©ã
d(6, 1) = 1 (6â 1), d(6, 2) = 2 (6â 1â 2), d(6, 3) = 2 (6â 8â 3)
d(6, 4) = 2 (6â 9â 4), d(6, 5) = 2 (6â 1â 5), d(6, 7) = 2 (6â 9â 7)
d(6, 8) = 1 (6â 8), d(6, 9) = 1 (6â 9), d(6, 10) = 2 (6â 8â 10)
以äžãã, ããŒã¿ãŒã¹ã³ã»ã°ã©ãã®ä»»æã® 2ç¹ v, wã«å¯Ÿã㊠d(v,w) = 1ãŸã㯠d(v,w) = 2ã§ããããšã瀺ãã.
4.1.2 éé£çµåéåãšåé¢éå
ããé£çµã°ã©ãããã©ã®çšåºŠã€ãªãã£ãã°ã©ãã§ãããããšãã芳ç¹ãã調ã¹ãé,ããã®ã°ã©ãããäœæ¬ã®èŸºãåãå»ã£ããéé£çµã°ã©ãã«ãªãã ?ãããã®ã°ã©ãããäœåã®ç¹ãåãå»ã£ããéé£çµã°ã©ãã«ãªãã ?ããšããææšãçšããããšãå€ã. åè ãéé£çµåéå (disconnecting set), åŸè ãåé¢éå(separating set) ãšåŒã¶. ããã§ã¯ãããããäŸãåãããããŠèŠãŠããããšã«ããã.
éé£çµåéå
éé£çµåéå : ãããé€å»ãããšã°ã©ããéé£çµãšãªã蟺ã®éå.ã«ããã»ãã : ãã®ã©ã®ãããªçéšåéåãéé£çµåéåã§ãªã, éé£çµåéå8 . å³ 4.74ã®éé£çµåéå {e1, e6, e7, e8}ã¯ã«ããã»ããã§ããã.蟺é£çµåºŠ (edge-connectivity) λ(G) : é£çµã°ã©ã Gã®æå°ãªã«ããã»ããã®å€§ãã. å³ã®ã°ã©ãã§ã¯Î»(G) = 2ã§ãã.
λ(G) ⥠kã®ãšã, ã°ã©ã G㯠k-蟺é£çµã§ãããšãã.
åé¢éå
åé¢éå : ãããé€å»ãããšã°ã©ããéé£çµãšãªãç¹ã®éå (蟺ãé€å»ãããšãã«ã¯ãã®æ¥ç¶èŸºãé€å»ããããšã«æ³šæ).ã«ããç¹ : 1åã®ç¹ã ããããªãåé¢éå.
8 ããããé€å»ãããšã°ã©ãã®æåæ°ãå¢ãã蟺ã®éåããšããŠå®çŸ©ãçŽãã°, ãéé£çµåéåã, ãã«ããã»ãããã¯ããããéé£çµã°ã©ãã«ãé©çšã§ããæŠå¿µã§ããããšã«æ³šæããã.
ãã㯠69ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
w
v x z
y
e1
e2
e5
e8
e3
e6
e7
e4
{e3,e6,e7,e8}
w
v x
y
z
e1 e5
e2
e4
å³ 4.74: ã«ããã»ãã {e3, e6, e7, e8} ãéžã¶ãšå³ã®ãããªéé£çµã°ã©ããåŸããã.
é£çµåºŠ κ(G) 9 : ã°ã©ã Gã®æå°ãªåé¢éåã®å€§ãã.
κ(G) ⥠kã®ãšã, ã°ã©ã G㯠k-é£çµã§ãããšãã.
(泚)
é£çµåºŠ κ(G)ãšã¯éä¿¡ç³»ã®ãããã¯ãŒã¯ (ã€ã³ã¿ãŒããããæãåºããŠé ããã°ãããšæããŸã) ãæ§ç¯ããéã«äŸ¿å©ãªéã§ãã. ã€ãŸã, ã°ã©ãã®åç¹ãã亀æå±ããããã¯ããµãŒããã§ãããšããã°, ãã®ã°ã©ã (ãããã¯ãŒã¯) Gã®é£çµåºŠã κ(G)ã§ãããšããããšã¯, κ(G)æªæºã®äº€æå± (ãµãŒã)ãæ éããŠã, æ®ãã®äº€æå± (ãµãŒã)ã®é£çµæ§ãä¿éãããŠããããšã«ãªã.
â é£çµåºŠ κ(G)ã¯ãããã¯ãŒã¯ã®ä¿¡é ŒåºŠãåæ ã, κ(G)ã倧ããªãããã¯ãŒã¯ã»ã©, ãã®ä¿¡é Œæ§ãé«ã.
äžæ¹, ååºã®ã蟺é£çµåºŠãλ(G) ããã®ãããã¯ãŒã¯ã«åœãŠã¯ããŠèããã°, λ(G)æªæºã®äŒéè·¯ãæ éããŠã, 亀æå± (ãµãŒã) ã®é£çµæ§ãä¿éãããŠããããšã«ãªãã®ã§, λ(G)ãäžã€ã®ãããã¯ãŒã¯ã®ä¿¡é ŒåºŠã®å°ºåºŠãšããŠçšããããšãã§ãã.
w
v x z
y
{w,x}
v
y
z
å³ 4.75: åé¢éå {w, x}ã«ãã£ãŠã§ããéé£çµã°ã©ã.
9 ãã®é£çµåºŠã¯, ååºã®èŸºé£çµåºŠãšåºå¥ããããã«ãç¹é£çµåºŠããšåŒã°ããããšããã.
ãã㯠70ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäžï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 4.3ã (2003幎床 æ å ±å·¥åŠæŒç¿ II(B) #2)
å³ã«äžããããã°ã©ã Gã«ã€ããŠä»¥äžã®åã (1)ïœ(5)ã«çãã.ã
A
C D
B
E F
G
H
e1
e2
e3e4
e5
e6
e7
e8
e9
e10
e11
e12 e13
(1) Gã®éé£çµåéåãäžã€æãã.(2) Gã®ã«ããã»ãããäžã€æãã.(3) Gã®æ©ãæãã.(4) Gã®åé¢éåãäžã€æãã.(5) Gã®ã«ããç¹ãäžã€æãã.
(解çäŸ)
(1)ã°ã©ãGã®éé£çµåéåã¯äŸãã°, {e7, e8}, {e10, e11}, {e0, e1, e2, e3} ãªã©ã§ãã.(2)ã°ã©ãGã®ã«ããã»ããã¯äŸãã°, {e7, e8}, {e10, e11}, {e10, e11, e12, e13} ãªã©ã§ãã.
(ã«ããã»ãã) â (éé£çµåéå) ã§ããããšã«æ³šæ.(3)ã°ã©ãGã®æ©ã¯ e9ã§ãã.(4)ã°ã©ãGã®åé¢éå㯠{B,D,E} ãªã©ã§ãã.(5)ã°ã©ãGã®ã«ããç¹ã¯ E, Fã§ãã.
ãã㯠71ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäžï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 4.4ã (2004幎床 æŒç¿åé¡ 4 )
ååã®è¬çŸ©ã§ã¯é£æ¥è¡å, æ¥ç¶è¡åãšåŒã°ããè¡åãçšããŠã°ã©ããè¡šçŸããæ¹æ³ãåŠãã ã, ããã 2ã€ã®è¡åã®ä»ã«ãã°ã©ããè¡šçŸããããã®è¡åã¯ååšã, ããããçšããããšã«ãã, ããæå¹ã«ã°ã©ãã«ã€ããŠã®èå¯ãé²ããããšãã§ãã. ããã§ã¯, ãã®ãããªè¡åã§ããã¿ã€ã»ããè¡å, åã³, ã«ããã»ããè¡åã«ã€ããŠã®æŒç¿åé¡ã解ãããšã«ãã, ãããè¡åã«é¢ããç解ãæ·±ããããšã«ããã.
ç¡åã°ã©ãGã®ã¿ã€ã»ããè¡å (tie-set matrix) B ãšã¯,åè¡ãGã®éè·¯Liã«,åå jãæ j â E(G)ã«å¯Ÿå¿ã, è¡åèŠçŽ bij ã
bij =
{1 (Liãæ j ãå«ã)0 (ãã以å€)
(4.111)
ãšè¡šãããè¡åã§ãã.äžæ¹, ã°ã©ã Gã®ã«ããã»ããè¡å (cut-set matrix) C ãšã¯, åè¡ iã Gã®ã«ããã»ãã Ci ã«, åå j ãæ j â E(G)ã«å¯Ÿå¿ã, åè¡åèŠçŽ ããããã
cij =
{1 (Ci ãæ jãå«ã)0 (ãã以å€)
(4.112)
ã§äžãããã. äŸãã°, å³ 4.76ã®ã°ã©ã Gã«ãããŠã¯, ã¿ã€ã»ããè¡å, ã«ããã»ããè¡åã¯ãããã
B =
(1 1 1 0 0 00 0 0 1 1 1
), C =
âââââââââââ
1 1 0 0 0 01 0 1 0 0 00 0 0 1 1 00 0 0 0 1 10 1 1 0 0 00 0 0 1 0 1
âââââââââââ
(4.113)
ãšãªã. ãããèžãŸããŠä»¥äžã®åãã«çãã.
(1)å³ 4.77ã®ã°ã©ã Gã®éè·¯ãå šãŠæ±ãã (ããããã« L1, L2, · · ·ã®ãããªã©ãã«ãä»ãã).(2)ã°ã©ã Gã®ã«ããã»ãããå šãŠæ±ãã (ããããã« C1, C2, · · ·ã®ãããªã©ãã«ãä»ãã).(3)ã°ã©ã Gã®ã¿ã€ã»ããè¡åB ãæ±ãã.(4)ã°ã©ã Gã®ã«ããã»ããè¡åC ãæ±ãã.(3)ã¿ã€ã»ããè¡åB ãšã«ããã»ããè¡åC ã®éã«æ¬¡ã®é¢ä¿åŒãæãç«ã€ããšã瀺ã.
BCT â¡ 0 (mod 2) (4.114)
ãã ã, CT ã¯è¡åC ã®è»¢çœ®è¡åãè¡šã, 0ã¯å šãŠã®æåããŒãã§ããè¡åãšããŠå®çŸ©ããã.
(解çäŸ)
(1) (2) å³ 4.78ãåç §ã®ããš.(3)éè·¯è¡åã®åã®å¢ããæ¹åã« L1, L2, L3, è¡ã®å¢ããæ¹åã«èŸºã®çªå· 1, 2, · · · , 5ã®ããã«ã©ãã«ä»ãã
ãã㯠72ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
a
b
c
e
d
1 2
3
4
56
L1
L2
a
bc
d
e
1
2
3
4
5
6
C1
C2
C3
C4
C5
C6
å³ 4.76: ã°ã©ã G ã®éè·¯ (å·Š) ãšã«ããã»ãã (å³).
a
c
bd
13
45
2
å³ 4.77: åé¡ã®ã°ã©ã G.
ãããã«æ±ºãããšè¡åB ã¯
B =
âââ
1 1 0 1 00 1 1 0 11 0 1 1 1
âââ (4.115)
ãšãªã.(4)ã«ããã»ããè¡åã®åã®å¢ããæ¹åã«ã«ããã»ããã®çªå· C1, C2, · · · , C6, è¡ã®å¢ããæ¹åã«èŸºã®çªå·
1, 2, · · · , 6ãå²ãæ¯ãããšã«æ±ºããã°, è¡åC ã¯
C =
âââââââââââ
1 1 1 0 01 0 0 1 00 1 0 1 10 0 1 0 10 1 1 1 01 1 0 0 1
âââââââââââ
(4.116)
ãšãªã.(5)äž¡è¡åã®ç©BCT ãäœããš
BCT =
âââ
1 1 0 1 00 1 1 0 11 0 1 1 1
âââ
ââââââââ
1 1 0 0 0 11 0 1 0 1 11 0 0 1 1 00 1 1 0 1 00 1 1 0 1 0
ââââââââ
ãã㯠73ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
a
b
c
dL1 L2
L3
C1
C2
C3
C4
12
3
4 5
C5
C6
å³ 4.78: åé¡ã®ã°ã©ãåã³, éè·¯ L1, L2, L3, ãããŠ, ã«ããã»ãã C1, C2, · · · , C6.
=
âââ
1 + 1 1 + 1 1 + 1 0 1 + 1 1 + 11 + 1 0 1 + 1 1 + 1 1 + 1 1 + 11 + 1 1 + 1 1 + 1 1 + 1 1 + 1 1 + 1
âââ =
âââ
0 0 0 0 0 00 0 0 0 0 00 0 0 0 0 0
âââ (mod 2)
ãšãªã, é¡æãæºãããã.
ᅵ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 4.5ã (2005幎床 æŒç¿åé¡ 4 )
1. å®å šã°ã©ãK3ã«é¢ã, ãã®åç¹ããµãŒãã«å¯Ÿå¿ã, K3ã®ã€ãªããæ¹ãããããããã¯ãŒã¯ãããª
ããŠãããã®ãšãã. ãã®ãããã¯ãŒã¯ã®å蟺ã確ç qã§æç·ããå Žå, ã°ã©ããäŸç¶ãšããŠé£çµã°ã©ãã§ããå Žåã«éã, ãã®ãããã¯ãŒã¯ã¯æ£åžžã«æ©èœããããšãããã£ãŠãã. ãã®ãšã, ãã®ãããã¯ãŒã¯ãæ£åžžã§ãã確ç (ãããã¯ãŒã¯ã®ä¿¡é ŒåºŠ) Rã qã®é¢æ°ãšããŠæ±ã, å³ç€ºãã.
2. ä»åã®è¬çŸ©ã§åŠãã ãéè·¯ããã«ããã»ãããã«é¢ããŠä»¥äžã®åãã«çãã.(1)ã°ã©ãã®äžã«èŸº eãå«ãéè·¯ã 2ã€ããå Žå, eãå«ãŸãªãéè·¯ãããããšãäŸãæããŠç€ºã.(2)ã°ã©ãã®äžã«èŸº eãå«ãã«ããã»ããã 2ã€ããå Žå, eãå«ãŸãªãã«ããã»ãããããããšãäŸãæããŠç€ºã.
(解çäŸ)
1. å®å šã°ã©ãåã³, 蟺ã 1æ¬æç·ããã°ã©ã (3çš®é¡), 蟺ã 2æ¬æç·ããã°ã©ã (3çš®é¡), 蟺ãå šãŠæç·ããã°ã©ã (1çš®é¡) ã®ããããã®ã°ã©ããå³ 4.79ã«ç€ºã. ããã§æ³šæãã¹ããªã®ã¯, åç¹ã¯ãããã¯ãŒã¯ã®ãµãŒãã«å¯Ÿå¿ããã®ã§, ãã®ãããªåé¡ã«ãããŠã¯, ã°ã©ãã¯ã©ãã«ä»ãã®ãã®ãèããã¹ãã§ãã. åŸã£ãŠ, ãã®å³ãããããã¯ãŒã¯ãæ£åžžã«åäœããã®ã¯å®å šã°ã©ãã®å Žå, åã³, 蟺ã 1æ¬ã ãæç·ããå Žåã«éã, ããããã®ç¢ºç㯠(1â q)3, 3q(1â q)2 ã§äžããããã®ã§, ãããã¯ãŒã¯ã®ä¿¡é ŒåºŠRã¯ãããäž¡è ã®åã§äžãããã. åŸã£ãŠ, qã®é¢æ°ãšããŠã® Rã¯
R(q) = (1â q)3 + 3q(1â q)2 (4.117)
ãšãªã. ãããå³ 4.80ã«æã.2. (1)(2)ã«è©²åœããã±ãŒã¹ãããããå³ 4.81, åã³, å³ 4.82ã«æã. å³ 4.81 ã«ç€ºããããã«, 蟺 eãå«ã
éè·¯ãšã㊠L1, L2 ãéžã¶ãš, eãå«ãŸãªãéè·¯ãšããŠ, ãã€ã§ã L1, L2 ã®åãã eãåé€ãããã®ã
第 3ã®éè·¯ L3ãšããŠãšãããšãã§ãã.
å³ 4.82 ã®ããã«èŸº e1, e2ãäžè§åœ¢ããªããŠããå Žåã«ã¯, ã«ããã»ãã {e, e1} ã«ãã£ãŠ, ã°ã©ãGã¯éšåã°ã©ãG1, åã³, G2 + G3ã«åé¢ã, ã«ããã»ãã {e, e2}ã«ãã£ãŠéšåã°ã©ãG1 + G2, åã³, G3
ãã㯠74ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
a
b c
a
cb
a
b c
a
b c
a
b c
a
b c
a
b c
a
b c
å³ 4.79: ããã§èãããããããã¯ãŒã¯ã®ç¶æ . äžãã, æç·ãŒã, 1æ¬æç·, 2 æ¬æç·, å šéšæç·ã®ã°ã©ã. ãããã¯ãŒã¯ãšããŠæ£åžžã§ããã®ã¯, æç·ãŒã, åã³, 1 æ¬æç·ã®å Žåã®ã¿.
0
0.2
0.4
0.6
0.8
1
0 0.2 0.4 0.6 0.8 1
R
q
å³ 4.80: ãããã¯ãŒã¯ã®ä¿¡é ŒåºŠ R ã®å蟺ã®æç·ç¢ºç q äŸåæ§.
ã«åé¢ããã, eãå«ãŸãªãã«ããã»ãããšã㊠{e1, e2}ããã€ã§ããšãããšãã§ããŠ, ãã®å Žåã«ã¯ã°ã©ãGãéšåã°ã©ã G1 + G3, åã³, G2 ã«åé¢ãã.
ãã㯠75ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
e
L1
L2
L3
å³ 4.81: 蟺 e ãå«ãéè·¯ãšããŠã¯, L1, L2 ãããã, e ãå«ãŸãªãéè·¯ãšããŠ, ãã€ã§ã L1, L2 ã®åãã e ãåé€ãããã®ã第 3ã®éè·¯ L3 ãšããŠãšãããšãã§ãã.
e
e1e2
G1
G2
G3
C1
C2
C3
å³ 4.82: å³ã®ããã«èŸº e, åã³, 蟺 e1, e2 ãäžè§åœ¢ããªããŠããå Žåã«ã¯, ã«ããã»ãã {e, e1}, {e, e2} 以å€ã«å¿ ã, {e1, e2}ãéžã¶ããšãã§ãã.
ᅵ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 4.6ã (2004幎床 æ å ±å·¥åŠæŒç¿ II(B)#1)
å³ã®ã°ã©ã Gã®åç¹ã¯ãããã¯ãŒã¯ Gå ã®ãµãŒããè¡šããšããã.
åãµãŒãã¯ç¢ºç pã§æ éãã. æ éãããµãŒãã¯ä»ã®ãµãŒããšæ å ±ã®ãããšããã§ããªãã®ã§, ãããã¯ãŒã¯ããé€å»ãã. kåã®ãµãŒããæ éãããšã, ãããã¯ãŒã¯å ã«æ®ããµãŒããããªãéšåãããã¯ãŒã¯ãæ£åžžã§ãã (é£çµã§ãã) 確ç pk ãæ±ãã. ãã ã, 1ã€ã®ãµãŒãã ããããªãããããã¯ãŒã¯ãã¯æ£åžžã§ãããšã¯èšããªãããšã«ãã. ãŸã, ã·ã¹ãã ã®ä¿¡é ŒåºŠ :
R(G) =â
k
pk
ãèšç®ã, pã®é¢æ°ãšããŠå³ç€ºãã.
(解çäŸ)
æ éãããµãŒãæ°ã k = 0, 1, 2,ã®ãšãã«çãæ®ããµãŒããããªãæ£åžžãªãããã¯ãŒã¯ãæããšå³ 4.83ã®ããã«ãªã (k = 3, 4ã®å Žåã¯åé¡å€ãªããšã¯æãã). åŸã£ãŠ, æ±ãã確ç pk ã¯
p0 = (1â p)4 (4.118)
ãã㯠76ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
1
3
2
4
2
3
4
1
34
1
3
2
3 4 1 21
3
2
3
k=0
k=1
k=2
å³ 4.83: æ£åžžãªãããã¯ãŒã¯.
p1 = 3p(1â p)3 (4.119)
p2 = 4p2(1â p)2 (4.120)
p3 = 0, p4 = 0 (4.121)
ã§ãã, ãã®çµæããã·ã¹ãã ã®ä¿¡é ŒåºŠ R(G)ã¯
R(G) =4â
k=0
pk = (1â p)4 + 3p(1â p)3 + 4p2(1â p)2 (4.122)
ãšãªã. ããã pã®é¢æ°ãšããŠãããããããã®ãå³ 4.84ã«èŒãã.
0
0.2
0.4
0.6
0.8
1
0 0.2 0.4 0.6 0.8 1
p
R(G)
(1-p)4
+ 3p(1-p)3
+ 4p2
(1-p)2
å³ 4.84: ä¿¡é ŒåºŠ : R(G) = (1 â p)4 + 3p(1 â p)3 + 4p2(1 â p)2
ãã㯠77ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäžï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 4.7 (2006幎床 æŒç¿åé¡ 4 )
ã°ã©ã G1 ãš G2 ã®çµã³: G = G1 + G2 ãšã¯ç¹éå : V (G) = V (G1) ⪠V (G2), ããã³, 蟺éå : E(G) =E(G1) âªE(G2) ⪠{uv|u â V (G1)ã〠v â V (G2)} ãæã€ã°ã©ãã®ããšã§ãã. ãã®ãšã以äžã®åãã«çãã.
(1)å®å šã°ã©ã K2ãš K3ã®çµã³ãå³ç€ºãã.(2)ç¹éåã nåã®éšåéå Vi (i = 1, · · · , n) ã«åå²ãã, Gã®ã©ã®èŸºããã®ç«¯ç¹ãç°ãªãéšåéåå
ã«ããããã«ã§ãããã®ã néšã°ã©ããšåŒã¶ã, ãã® néšã°ã©ããç¹ã«, åå²ã®ä»»æã®éšåéåå ã«ããåç¹ã, ãã®ä»ã®éšåéåå ã«ããå šãŠã®ç¹ãšçµã³ã€ãããããšã, ãã®ã°ã©ããå®å š néšã°ã©
ããšåŒã³, Kp1,p2,···,pn (pi = |Vi|) ãšæžã. ãã®ãšã,
Kp1,p2,···,pn = Kp1 + Kp2 + · · ·+ Kpn (4.123)
ãæãç«ã€ããšã瀺ã. ãã ã, Gã¯ã°ã©ã Gã®è£ã°ã©ããè¡šããã®ãšãã. (â» ãããã«ãããã°,å®éã« K2,2,2ã®å Žåãå³ç€ºããŠã¿ã.)
(解çäŸ)
(1) K2,K3 ã¯ããããç¹æ°ã 2,3ã®å®å šã°ã©ãã§ãã, ãç·åããšãäžè§åœ¢ããããã«çžåœãã. ããã§åé¡ãšãªã£ãŠãããã®äž¡è ã®ãçµã³ãK2 + K3 ã¯, åé¡æã«å®çŸ©ãããŠããããã« K2,K3ã®èŸºã¯ãã®
ãŸãŸæ®ãã, ãã€, K2å ã®ç¹ã¯ K3å ã®ç¹ãšçµã¶ããšã«ãã£ãŠã§ãã蟺ããæãã°ã©ãã§ãããã, å³4.85 ã®ãããªã°ã©ããåé¡ã®çµã³ã§ãã.
K
K
2
3
å³ 4.85: K2 ãš K3 ã®çµã³.
(2)ã¯ããã«, å®å šäžéšã°ã©ã K2,2,2 ã«å¯ŸããŠé¢ä¿åŒã¯
K2,2,2 = K2 + K2 + K2 (4.124)
ãšæžããã, ãã®äž¡èŸºã®æå³ããã°ã©ããå ·äœçã«æã, äž¡è ãå圢ã§ãããåŠãã確èªããŠã¿ãã.ã¯ããã«å·ŠèŸºã¯å®å šäžéšã°ã©ãã®å®çŸ©ãã, å³ 4.86(å·Š) ã®ããã« A,B,C ã°ã«ãŒãã«ãããã 2ç¹ãã€å±ããç¹ã®ãããããèªåã®ã°ã«ãŒã以å€ã«å±ããç¹ã®å šãŠãšçµã³ã€ããããšã«ããã§ãã. äžæ¹ã®å³èŸºã® 3ã€ã® K2ã¯, å®å šã°ã©ããå šãŠã®ç¹ã©ãããçµãã§ã§ããã°ã©ãã§ãã£ãããšãèãããš, ãã㯠2åã®å€ç«ç¹ãããªãã空ã°ã©ãããšããããšã«ãªã. åŸã£ãŠ, ãã® 3ã€ã®ã°ã©ãã®åã ã«å¯ŸããŠ,蟺ã¯ååšããªãã®ã§, ãã® 3ã€ã®ç©ºã°ã©ãã A,B,Cã®ããã«åã¥ã, åã ã®ç©ºã°ã©ãã®ç¹ã uAçãšåŒ
ã¶ããšã«çŽæãããš (ã€ãŸã, uA â V (A)ç), (4.124)åŒã®å³èŸºã¯èŸºéå :
E(K2 + K2 + K2) = {uAuB|uA â V (A)ã〠uB â V (B) }⪠{uBuC|uB â V (B)ã〠uC â V (C) }⪠{uCuA|uC â V (C)ã〠uA â V (A) } (4.125)
ãã㯠78ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
K 2,2,2
A groupB group
C group
K 2
K 2
K 2
A
B
C
å³ 4.86: K2,2,2(å·Š) ãš K2 + K2 + K2(å³).
ãšãªã, ãããå³ç€ºãããšå³ 4.86(å³)ã®ããã«, K2,2,2 ãšå圢ãªã°ã©ããåºæ¥äžãã.以äžã®è°è«ã¯çŽã¡ã«äžè¬ã®å®å š néšã°ã©ãã«æ¡åŒµããããšãã§ãã. Kpi ã®è£ã°ã©ã Kpi 㯠piåã®å€
ç«ç¹ãããªã空ã°ã©ãã§ãã, ãã®ç¹éåã V (i)ãšããã°, çµã³: Kp1 + · · ·Kpn 㯠nåã®ã°ã«ãŒãã®
äžããä»»æã®ç°ãªã 2ã°ã«ãŒã V (i), V (j)ã«å±ããç¹ã©ãããçµãã§ã§ããå šãŠã®èŸºéåã§ãããã,ããã¯ãŸãã«å®å š néšã°ã©ã Kp1,···,pn ã®æãæ¹ãã®ãã®ã§ãã. åŸã£ãŠ, é¡æã®é¢ä¿åŒã¯æç«ãã.
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ãäŸé¡ 4.8 ã (2004幎床æ å ±å·¥åŠæŒç¿ II(B) #1)
å³ã«äžããã°ã©ãã®å§ç¹ uããçµç¹ vãžè³ãå šãŠã®çµè·¯ã®äžã§æçã®ãã®ãæ±ãã.
uv
1
2
3
1
3 4
1
4
3
4
5
1
2
3
4
3
3
5
ãªã, ã°ã©ãã®å蟺ã«èšãããæ°åã¯ãã®åºéã®è·é¢ã§ãããã®ãšãã. ãªã, åãæçè·é¢ãäžããçµè·¯ãè€æ°ååšããå Žåã«ã¯, ãããå šãŠãçããããš.
(解çäŸ)å³ 4.87ã®ããã«åç¹ã« AïœHã®ååãä»ãã. åç¹ xãŸã§ã®æçè·¯ã l(x)ãšæžãããšã«ããã°, ãããã¯
u
2
3
11
3 4
3
4
1
5
4
1
3
34
2
3
5
v
A
B
C
D
E
F
G
H
å³ 4.87: å³ã®ããã«åç¹ã«ååãä»ãã. 倪ç·ç¢å°ãæ±ããæçè·¯ã§ãã.
ãã㯠79ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
é 次ã«æ±ããããšãã§ããŠ
l(u) = 0
l(A) = l(u) + 1 = 1
l(B) = l(u) + 2 = 2
l(C) = min{l(u) + 3, l(A) + 1, l(B) + 3} = min{3, 2, 5} = 2
l(D) = min{l(A) + 4, l(C) + 1} = min{5, 3} = 3
l(E) = min{l(C) + 4, l(B) + 3} = min{6, 5} = 5
l(F) = min{l(D) + 4, l(F) + 5} = min{7, 10} = 7
l(G) = min{l(D) + 3, l(F) + 4} = min{6, 11} = 6
l(H) = min{l(F) + 2, l(E) + 1} = min{9, 6} = 6
l(v) = min{l(G) + 3, l(H) + 5, l(F) + 3} = min{9, 11, 10} = 9
ã®ããã«ãªã. åŸã£ãŠ, æç路㯠uâ Aâ Câ Dâ Gâ v ã§ãã, ãã®ãšãã®æçè·¯é·ã¯ 9ã§ãã.
â» èšç®æ©ãçšããæçè·¯é·ã®èšç®äŸãšããã°ã©ã ã¯äŸé¡ 11.6ãåç §ã®ããš.
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ãäŸé¡ 4.9 ã (2005幎床æ å ±å·¥åŠæŒç¿ II(B) #1)
ã°ã©ã G㯠n = 2kåã®ç¹ãæã€åçŽã°ã©ãã§äžè§åœ¢ã¯æããªããã®ãšãã. ãã®ãšã以äžã®åãã«çãã.
(1) k = 3ã®ãšãGã®èŸºæ°mã®äžçm+ (⥠m)ãæ±ã, ãã®äžçm+ãäžããã°ã©ãGã®äŸãäžã€æã.(2) Gã®èŸºæ°ã¯ k2以äžã§ãã (m †m+ = k2)ããšãæ°åŠçåž°çŽæ³ãçšããŠèšŒæãã.
⻠泚 : æ°åŠçåž°çŽæ³ãçšããªãããæ¹ã§ã蚌æã§ãããšããå Žåã«ã¯ããã解çãšããŠãè¯ã.
(解çäŸ)
(1) k = 3ã§ãããã, ç¹æ°ã¯ n = 2à 3 = 6ã§ãã. ãã®ãšã, ã°ã©ã Gãäžè§åœ¢ãæããªãããã«æããšå³ 4.88(å·Š)ã®ããã«ãªã, ãã®ãšãã®èŸºæ°ã¯m+ = 9 = 32 = k2 ãšãªã, ãã®å³ 4.88ã« 1æ¬ã§ã蟺ãå ãããšäžè§åœ¢ãã§ããŠããŸãã®ã§, ããã蟺ã®äžéãäžãã.
12
3
4
6
5 2 5 6
1 3 4
å³ 4.88: k = 3, n = 2k = 6 ã®å Žåã®äžè§åœ¢ãæããªãæ倧ã®èŸºãäžããã°ã©ãã®äŸ (å·Š). ãã®ã°ã©ãã¯å®å šäºéšã°ã©ã K3,3 ãšååã§ãã (å³).
(2)æ°åŠçåž°çŽæ³ã§ç€ºã.k = 1ã®ãšã, n = 2à 1 = 2, k2 = 1 = m+ ã®æç«ã¯æãã (ã°ã©ãG㯠2ç¹ãããªããæšãã§ãã).ããã§, kã®ãšãã«é¡æã®æç«ãä»®å®ãã. ã€ãŸã, n = 2k ã®ãšã, m †m+ = k2 â¡ m+(k)ãšãã.
ãã㯠80ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãã®ãšã, (1)ã®çµæãã, äžè§åœ¢ãæããªã蟺æ°æ倧ã®ã°ã©ãã¯å®å šäºéšã°ã©ããšååã§ãã, Ks,tã®
ç¹æ°ã s+ t, 蟺æ°ã sà tã§äžããããããšãèãããš, s = t = kã®å Žåã«ã¯ç¹æ°ã¯ n = 2k, 蟺æ°ã¯k2ã§ãã, é¡æãæºãããŠããããšã«æ³šç®ãã (å³ 4.88(å³)åç §). ãã®å®å šäºéšã°ã©ãKk,k ã«ç¹ã 2ã€å ã (A,Bãšãã), Aãšäºéšã°ã©ãã®çœäžžãçµã³ (蟺ãæ°ãã«mæ¬ã§ãã), Bãšäºéšã°ã©ãã®é»äžž
ãçµã¶ (蟺ãæ°ãã«mæ¬ã§ãã). ãããŠæåŸã« A,Bã©ãããçµã¶ (蟺ãæ°ãã« 1æ¬ã§ãã)ãšç¹æ°ã¯2k + 2 = 2(k + 1)ã§ãã, ãã®ãšãã®èŸºæ°ã¯
m+(k + 1) = k2 + 2k + 1 = (k + 1)2 (4.126)
ãšãªã, äžèšã®ããã«ããŠã§ãäžããã°ã©ãã«ä»»æã® 1蟺ãå ãããšäžè§åœ¢ãã§ããŠããŸãã®ã¯æãããªã®ã§, ãããäžéã§ãã, k + 1ã®ãšãã«é¡æã®æç«ãèšãã. 以äžã«ãã, Gã®èŸºæ°ã¯ k2 以äžã§
ããããšã瀺ãã.
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ãäŸé¡ 4.10 ã (2006幎床æ å ±å·¥åŠæŒç¿ II(B) #1)
nãã°ã©ãã®ç¹æ°, mã蟺æ°ãšãã. ãã®ãšã以äžã®åãã«çãã.
(1)é¢ä¿åŒ:m > nâ1C2
ãæºããåçŽã°ã©ãã¯é£çµã§ããããšã瀺ã.(2) n > 1ã«å¯ŸããŠ
m = nâ1C2
ã§ããéé£çµã°ã©ãã®äŸãäžã€æãã.
(解çäŸ)
(1) nãäžå®ã§ããå Žå, ã°ã©ãã®æåæ° kãå€ããªãã°ãã®åã®èŸºæ°ãå°ãªããªãããšã¯æãã. åŸã£ãŠ,ããã§ã¯ç¹æ° nãããªãéé£çµã°ã©ãã®ãã¡æå°ã®æåãæã€ãã®, ããªãã¡, k = 2ã®å Žåãèãã.ãã®ãšã, 蟺æ°ãæ倧åããã°ã©ã㯠n â 1åã®ç¹ãããªãå®å šã°ã©ãKnâ1 ãšå€ç«ç¹ 1ç¹ãããªãã°ã©ãã§ãããã, ãã®èŸºæ°ã¯ nâ1C2 ã§ãã. ãã®å€ç«ç¹ãšKnâ1 ã®ä»»æã® 1ç¹ãçµã¶ãšåçŽé£çµã°ã©ããåŸãããããšã«ãªãã®ã§, ãããåçŽé£çµã°ã©ãã®èŸºæ°mã®äžéãäžããããšã«ãªã. ã€ãŸã
m ⥠nâ1C2 + 1 (4.127)
ã§ãã. ããã¯èŸºæ°mã¯æŽæ°ã§ããããšãèãããšæ¬¡ã®ããã«æžãæããããšãã§ãã.
m > nâ1C2 (4.128)
以äžãã, åçŽã°ã©ãã®èŸºæ°ã¯m > nâ1C2ãæºãããšããé¡æã瀺ãããšãã§ãã.(2) n = 4ãšãããš, K3(äžè§åœ¢)ãšå€ç«ç¹ 1ç¹ãã§ãã. ãã®èŸºæ°ã¯ 3C2 = 3ã§ãã.
ãã㯠81ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäžï¿œ
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ãäŸé¡ 4.11 ã (2007幎床 æŒç¿åé¡ 4 )
(1)ä»»æã®ã°ã©ã Gã«ãããŠ, 次æ°ãå¥æ°ã§ããç¹ã®åæ°ã¯å¿ ãå¶æ°åããããšãé¢ä¿åŒ:
âuâV (G)
deg(u) = 2ε(G)
ãçšããŠç€ºã.(2)åçŽã°ã©ã Gã®ç¹ã®åæ°ã 2以äžãªãã°, Gã«ã¯å¿ ãåã次æ°ãæ〠2ã€ã®ç¹ãååšããããšã瀺ã.
(解çäŸ)
(1)ã°ã©ã Gã«ååšããå šãŠã®ç¹éå V (G) ãå¥æ°æ¬¡, å¶æ°æ¬¡ã®éšåéå: Vodd = {u | deg(u)ãå¥æ° },Veven = {u | deg(u)ãå¶æ° } ã«åãã. ãã®ãšã, äžããããé¢ä¿åŒã¯
2ε(G) =â
uâVodd
deg(u) +â
uâVeven
deg(u) (4.129)
ãšæžããã, æããã«, äžåŒã®ãã¡ã® 2ε(G)ãšâ
uâVevendeg(u)ã¯å¶æ°ã§ãã. åŸã£ãŠ, äžé¢ä¿åŒã®äž¡
蟺ã®å¶å¥ãåãããããã«â
uâVodddeg(u)ã¯å¶æ°ã§ãªããã°ãªããªãã, ãã®åã®äžã®åèŠçŽ deg(u)
ãå¥æ°ã§ããããšãèããã°, ãã®åã«çŸããåèŠçŽ ã®ç·æ°ã¯å¶, ããªãã¡, 次æ°ãå¥æ°ã§ããç¹ã¯å¶æ°åãªããã°ãªããªã. åŸã£ãŠ, ãä»»æã®ã°ã©ã Gã«ãããŠ, 次æ°ãå¥æ°ã§ããç¹ã®åæ°ã¯å¿ ãå¶æ°åãããããšã瀺ããã.
(2)ã°ã©ã Gã®ç¹ã®æ°ã nãšãã. ãã®ãšã, GãåçŽã°ã©ãã§ããã°, æããã« Gã®å¯èœãªæ倧次æ°ã¯
nâ 1ã§ãã. åŸã£ãŠ, ãã, nç¹ãã¹ãŠã®æ¬¡æ°ãç°ãªããšä»®å®ãããš, ãããã®æ¬¡æ°ã¯ 0, 1, 2, · · · , nâ 1ãšãªãã, æããã«æ¬¡æ° 0ã®ç¹ãšå¯èœãªæå€§æ¬¡æ° nâ 1ã®ç¹ãã°ã©ã Gäžã«å ±åããããšã¯ã§ããªã.åŸã£ãŠ, ãåçŽã°ã©ã Gã®ç¹ã®åæ°ã 2以äžãªãã°, Gã«ã¯å¿ ãåã次æ°ãæ〠2ã€ã®ç¹ãååšãããããšã瀺ãã.
ãã㯠82ããŒãžç®
83
第5åè¬çŸ©
5.1 ãªã€ã©ãŒã»ã°ã©ããšããã«ãã³ã»ã°ã©ã
ããã§ã¯æ å ±å·¥åŠçã«å¿çšãããå Žé¢ãå€ããªã€ã©ãŒã»ã°ã©ããšããã«ãã³ã»ã°ã©ãã«ã€ããŠåŠã¶.
5.1.1 ãªã€ã©ãŒã»ã°ã©ã
ãªã€ã©ãŒã»ã°ã©ã (Eulerian graph) : å šãŠã®èŸºãå«ãéããå°éãããé£çµã°ã©ã.åãªã€ã©ãŒã»ã°ã©ã (semi-Eulerian graph) : å šãŠã®èŸºãå«ãå°éãããé£çµã°ã©ã (éããŠããªã).
Eulerian graph Semi-Eulerian graph
å³ 5.89: ãªã€ã©ãŒã»ã°ã©ã (å·Š) ãšåãªã€ã©ãŒã»ã°ã©ã (å³) ã®äžäŸ.
å®ç 6.2é£çµã°ã©ã Gããªã€ã©ãŒã»ã°ã©ããšãªãå¿ èŠååæ¡ä»¶ã¯ G ã®ç¹ã®æ¬¡æ°ãå šãŠå¶æ°ã§ããããšã§ãã.
(蚌æ)â (å¿ èŠæ§)Gã®ãªã€ã©ãŒå°é P ãããäžç¹ãééããæ¯ã« 2ãå ããŠãããš, å šãŠã®èŸºã¯ã¡ããã© 1åãã€å«ãŸããã®ã§, åç¹ã§ãã®åã¯ãã®ç¹ã®æ¬¡æ°ã«çãã, ããã, ããã¯å¶æ°ã§ãã.
â (ååæ§)åç¹ã®æ¬¡æ°ã¯å¶æ°ã§ãã, ãã€, é£çµã§ãããšãããš, æç§æž p. 43 è£é¡ 6.1 ãã, ãã®é£çµã°ã©ã Gã«ã¯éè·¯ Cããã. åŸã£ãŠ, ãã®ããšã§ãªã€ã©ãŒã»ã°ã©ããšããŠGãæ§æã§ããã°ãã. ã€ãŸã, ãã®ããšã§å ·äœçãªãªã€ã©ãŒã»ã°ã©ãã®æ§ææ³ãæ瀺ããã°èšŒæã¯çµäºã§ãã.ããŠ, èªæã§ããã, éè·¯ Cã«Gã®å šãŠã®ç¹ãå«ãŸããŠããã°, ãã®éè·¯ãã®ãã®ããªã€ã©ãŒã»ã°ã©ããš
ãªãã®ã§èšŒæã¯çµäºãã. åŸã£ãŠ, 以äžã§ã¯ãã以å€ã®ã±ãŒã¹ã«å¯ŸããŠ, ãªã€ã©ãŒã»ã°ã©ãã®æ§ææ³ãæ瀺ãã.ãŸã, å³ 5.90ã®ããã« Gããéè·¯ Cã®èŸºãé€å»ããŠã§ããã°ã©ã (äžè¬ã«ã¯éé£çµã§ããã, ãªã€ã©ãŒ
å°éããã) ã Hãšãã. Gã®é£çµæ§ãã, ã°ã©ã Hã®åæå㯠Cãšå°ãªããšã 1ç¹ãå ±æããŠããããšã«æ³šæããã. åŸã£ãŠ, ãã®ãããªç¶æ³äžã§, Cäžã®ä»»æã®äžç¹ããã¹ã¿ãŒãã, Cã®èŸºããã©ã. ãããŠ,Hã®å€ç«ç¹ã§ãªãç¹ã«åºããããã³ã«, ãã®ç¹ãå«ã Hã®æåã®ãªã€ã©ãŒå°é (Cèªèº«ã¯ãªã€ã©ãŒã»ã°ã©
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
C
HH
å³ 5.90: èããé£çµã°ã©ã G ã¯éè·¯ C ãšãããããªã€ã©ãŒå°éãå«ãæå H ãããªã. C èªèº«ã¯ãªã€ã©ãŒã»ã°ã©ãã§ãããã,å¥æ°æ¬¡ã®ç¹ãå«ãŸãªã. åŸã£ãŠ, H ãå¥æ°æ¬¡ã®ç¹ãå«ãŸãªã.
ãã§ãããã, å¥æ°æ¬¡ã®ç¹ãå«ãŸã, åŸã£ãŠ, åæåã§ããHãå¥æ°æ¬¡ã®ç¹ãå«ãŸãªã)ããã©ã, ãã®ç¹ã«æ»ã, ãŸã Cã®èŸºããã©ã£ãŠè¡ãã»ã»ã»ãšããæäœãç¹°ãè¿ã, Cäžã®åºçºç¹ã«æ»ããšããäœæ¥ãè¡ãããšã«ãã, ãªã€ã©ãŒå°éãåŸãã, ãã©ã£ãŠæ¥ãéãã€ãªããããšã«ãã, æ±ããã¹ããªã€ã©ãŒã»ã°ã©ããæãããšãã§ãã (蚌æçµãã).
次ã«ãªã€ã©ãŒã»ã°ã©ãã«é¢ããäŸé¡ãäžã€èŠãŠããã.ï¿œ
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ãäŸé¡ 5.1ãªã€ã©ãŒã»ã°ã©ãã«é¢ããŠä»¥äžã®åãã«çãã.
(1)ã©ã㪠nã«å¯ŸããŠå®å šã°ã©ãKn ã¯ãªã€ã©ãŒã»ã°ã©ãã«ãªãã ?(2)å®å šäºéšã°ã©ã Ks,tã®ã©ã®ãããªå Žåããªã€ã©ãŒã»ã°ã©ããšãªãã ?(3)ã©ã®ãã㪠nã«å¯ŸããŠè»èŒªWn ã¯ãªã€ã©ãŒã»ã°ã©ããšãªãã ?
(解çäŸ)
(1)å®å šã°ã©ãKnã®ä»»æã® 1ç¹ã®æ¬¡æ°ã¯ nâ 1ã§ãããã, nâ 1 =å¶æ°ã®å Žåã«éã, Knã¯ãªã€ã©ãŒã»
ã°ã©ããšãªã. åŸã£ãŠ, äŸãã°, K5ã¯ãªã€ã©ãŒã»ã°ã©ãã§ããã, K4ã¯ãªã€ã©ãŒã»ã°ã©ãã§ã¯ãªã.(2)å³ 5.91ã®ããã«, s ⥠2, åã³, tãå¶æ°ã§ããã°, aâ 1â bâ 2â aâ 3â bâ 4â aâ 5â b ã®
ãããªçµè·¯ã§, a, bã亀äºã«çµç±ãããªã€ã©ãŒå°éãäœãããšã¯åžžã«å¯èœã§ãã (å³ã®äŸã§ã¯ tãå¥æ°
ãªã®ã§, ã§ããã°ã©ãã¯åãªã€ã©ãŒã§ãã, ãªã€ã©ãŒã§ã¯ãªã. t = 6ã®å Žåã«ã¯ãªã€ã©ãŒãšãªãããšãåèªã確èªããŠã¿ãããš). åŸã£ãŠ, s ⥠2ã®ãšã, å®å šäºéšã°ã©ãKs,tã¯ãªã€ã©ãŒã»ã°ã©ããšãªã.
1 2 3 4 5
a b
K 2,5
å³ 5.91: å®å šäºéšã°ã©ã K2,5. ãªã€ã©ãŒå°éãååšã, ãªã€ã©ãŒã»ã°ã©ãã§ãã.
(3)è»èŒªã¯å šãŠã® nã«å¯ŸããŠ, Cnâ1 ãš 1ç¹ãšã®çµåéšã®æ¬¡æ°ã¯ 3(å¥æ°)ã§ãããã, ãªã€ã©ãŒã»ã°ã©ããš
ãã㯠84ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ã¯ãªããªã.
ããŠ, å®ç 6.2 ã«ãã,æã ã¯äžããããã°ã©ãã®åç¹ã®æ¬¡æ°ã調ã¹ãããšã«ãã,ãã®ã°ã©ãããªã€ã©ãŒã»ã°ã©ããåŠãã調ã¹ãããšãã§ããããã«ãªã£ã. åŸã£ãŠ, 以äžã®ãããªåé¡ã«å¯Ÿã, æã ã¯çŽã¡ã«çããããšãã§ãã.ï¿œ
ᅵ
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ãåé¡
7ã€ã®å¬ãäŒå Ž a,b,c,d,e,f,g ã®äž»å¬è ããã®é è·¯ã決ããéã«, äžçæžãã«åºã¥ãéé ãæ¡çšããããšããŠãã. åäŒå ŽããåºãŠããéã®æ¬æ°ã¯ä»¥äžã®è¡šã®éãã§ãã.
äŒå Ž a b c d e f g
éæ° 4 4 4 4 4 4 2
ãã®å Žå, äž»å¬è ã®æããäžçæžãé è·¯ãã¯äœæå¯èœã§ããã ?
ãã®åé¡ã®çãã¯ãã¡ãã, ãå¯èœãã§ãã (å šãŠã®ç¹ã®æ¬¡æ°ãå¶æ°ã§ãããã).
ããã, å®éã«ãã®ã°ã©ãã®äžãããªã€ã©ãŒå°éãæ¢ããšãªããš, ã°ã©ãã«å«ãŸããç¹ã®æ°ãå€ããªãã«åŸã£ãŠé£ãããªãããšã¯ãããã§ããã. ã©ã®ããã«ããã°ç³»çµ±çã«ãªã€ã©ãŒå°éãäœãããšãã§ããã§ãããã ?
ãã®åãã«å¯ŸããçããšããŠ, Fleury (ãã©ãŒãªãŒ)ã®ã¢ã«ãŽãªãºã ãç¥ãããŠãã. ãã®èšŒæã¯æç§æžp. 45ãèªãã§é ãããšã«ããŠ, ããã§ã¯, ã¢ã«ãŽãªãºã ãæããŠããã®ã§, åèª, äžã®å¬ãäŒå Žã®é è·¯äœæã«çšããŠã¿ãããš (â äŸé¡ 6.3).
Fleury ã®ã¢ã«ãŽãªãºã
ä»»æã®ç¹ããåºçºã, 次ã®èŠåã«åŸãéãèªç±ã«èŸºããã©ãã°ãªã€ã©ãŒå°éãåŸããã.
(1)ãã©ã£ã蟺ã¯é€å»ã, å€ç«ç¹ãçããå Žåã«ã¯ãããé€å»ãã.(2)ã©ã®æ®µéã§ã, ä»ã«ãã©ã蟺ããªãå Žå以å€ã«ã¯æ©ããã©ããª.
5.1.2 ããã«ãã³ã»ã°ã©ã
ããã«ãã³ã»ã°ã©ã (Hamiltonian graph) : ããã«ãã³éè·¯ã«ãããªãã°ã©ã.ããã«ãã³éè·¯ (Hamiltonian cycle) : ã°ã©ã Gã®åç¹ãã¡ããã©äžåºŠã ãéãéããå°é.åããã«ãã³ã»ã°ã©ã (semi-Hamiltonian graph) : å šãŠã®ç¹ãéãéãããã°ã©ã (éããŠã¯ããªã).
äžããããã°ã©ããããã«ãã³ã»ã°ã©ãã§ãããã©ããã«é¢ããŠã®å€å®ã«ã¯æ¬¡ã®Ore (ãªãŒã¬) ã®å®çã圹ç«ã€å Žåãå€ã.
ãã㯠85ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
å®ç 7.1 (Ore (ãªãŒã¬)ã®å®ç)
åçŽã°ã©ã Gã«ã¯ n(⥠3)åã®ç¹ããããšãã. é£æ¥ããŠããªãä»»æã® 2ç¹ v, wã«é¢ããŠ
deg(v) + deg(w) ⥠n (5.130)
ãæç«ãããšãGã¯ããã«ãã³ã»ã°ã©ãã§ãã.
(蚌æ)
èçæ³ã§ç€ºã.ãã°ã©ã Gã¯ããã«ããã¢ã³ã»ã°ã©ãã§ã¯ãªãã (5.130)ãæºããããšä»®å®ã, ãã®ççŸãå°ã.G㯠(ãããã) ããã«ãã³ã»ã°ã©ãã§ã¯ãªããšãããš, Gã«ã¯å šãŠã®ç¹ãå«ãé :
v1 â v2 â v3 â · · · â vn
ããã. ããã, ããã§, v1 ãš vn ãé£æ¥ããŠãããšããŠããŸããš, ã°ã©ã Gãããã«ãã³ã»ã°ã©ãã«ãªã£ãŠããŸãã®ã§, v1 ãš vn ã¯é£æ¥ããŠããªããã®ãšãã.åŸã£ãŠ, v1, vn ã«é¢ããŠãäžçåŒ (5.130)ãæç«ã (èçæ³ã®ä»®å®),
deg(v1) + deg(vn) ⥠n
ãæãç«ã€. ãã£ãŠ, v1, vn ã®æ¬¡æ°ã¯ 2以äžãªã®ã§ (n = 3ã®å Žå, deg(v1) = 2, deg(vn) = 1ã¯ã©ããªã®ã,ãšæã人ããããããããªãã, ãã®ãšãã® 3ç¹ã®é åãèãããš, ããã¯ããããªãããšããããã§ããã), vi 㯠v1 ã«é£æ¥ã, viâ1 㯠vn ã«é£æ¥ãããã㪠2ç¹ vi, viâ1 ãååšãã (å³ 5.92åç §). ãã®ãšã, å
v1
v2 v i-1 vi v n-1
vn
å³ 5.92: Ore ã®å®çã®ååæ§ã®èšŒæã§çšããã°ã©ã.
çŽã°ã©ã Gã«ã¯
v1 â v2 â · · · â viâ1 â vn â vi â v1
ãªãéè·¯ãååšããããšã«ãªã, ççŸ. (蚌æçµãã) 10 .
æåŸã« Oreã®å®çã«é¢ãã次ã®äŸé¡ãèŠãŠããããšã«ããã.ï¿œ
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ãäŸé¡ 5.2 ã (2003幎床ã¬ããŒãèª²é¡ #4 åé¡ 1 )
ã°ã©ã Gã«ã¯ nåã®ç¹ããã, (n â 1)(n â 2)/2 + 2æ¬ã®èŸºããããšãã. ãã®ãšã, Oreã®å®çãçšããŠ, ãã®ã°ã©ã Gã¯ããã«ãã³ã»ã°ã©ãã§ããããšã瀺ã.
(解çäŸ)
蟺ã®æ°ã nâ 1æ¬ã®å®å šã°ã©ãKnâ1ã®èŸºã®æ¬æ°ã¯ (nâ 1)(nâ 2)/2æ¬ã§ãã, ããã«ãã³ã»ã°ã©ããå€é蟺çãå«ãŸãªãåçŽã°ã©ãã§ããããšãèæ ®ãããš, G㯠Knâ1ãš 1ç¹ vã®åèš nç¹ãããªã, v㯠Knâ1
ãæ§æããä»»æã® 2ç¹ w, xãšå³ 5.93ã®ããã«çµã³ã€ããŠãããšèããŠãã. åŸã£ãŠ, ãã®å Žåã®èŸºã®æ°ã¯10 ãã®å®çã¯ããã«ãã³ã»ã°ã©ãã§ããããã®ååæ¡ä»¶ãäžããŠããããšã«æ³šæ. åŸã£ãŠ, æ¡ä»¶åŒ (5.130) ãæºãããªããããªããã«ãã³ã»ã°ã©ããååšããâ äŸé¡ 5.3 ã® 3 ãåç §ã®ããš.
ãã㯠86ããŒãžç®
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K n-1
v
w
x
å³ 5.93: å®å šã°ã©ã Knâ1 ãšç¹ v ã 2ç¹ w, xã§ç¹ãã£ãŠããã°ã©ã G. ç¹ã®åæ°ã¯ n, 蟺ã®æ¬æ°ã¯ (nâ 1)(nâ 2)/2 + 2ã§ãã.
(nâ 1)(nâ 2)/2 + 2æ¬ã§ãã, åé¡æã«æ¡ä»¶ãšããŠäžãããã蟺ã®æ¬æ°ãšãªã.ããŠ, Kn ãæ§æããä»»æã® 2ç¹ã¯å¿ ãé£æ¥ããã®ã§, èããããå¯èœæ§ãšããŠã¯, ä»»æã®é£æ¥ããªã 2ç¹ã Knâ1 ãæ§æããä»»æã® 1ç¹ u1(ï¿œ= w, x)ãšç¹ vã®å Žåã§ããã, ãã®ãšãã«ã¯
deg(u1) + deg(v) = nâ 2 + 2 = n (5.131)
ãšãªã, Oreã®å®çãçåŒããããã§æºããããšãããã.ãŸã, äžèšä»¥å€ã«ãäŸãã°Knâ1ãæ§æããä»»æã®äžèŸºãåé€ã, ãã®èŸºã§ç¹ vãšKnâ1ã®ä»»æã®äžç¹ãçµ
ã¶å Žåãããããã, ãã®å Žåã«ã¯ deg(v) = 3, 蟺ãåé€ããç¹ zã®æ¬¡æ° deg(z) = nâ 3ã§ãããã, çµå±deg(v) + deg(z) = nãšãªã, ãã¯ã Oreã®å®çãæºãã. ãã®ãããªå€æãç¹°ãè¿ããŠã, Oreã®å®çãç Žããããšããªãããšã¯æãããªã®ã§çµå±, é¡æ, å³ã¡ãnåã®ç¹ããã³ (nâ 1)(nâ 2)/2 + 2æ¬ã®èŸºãããªãã°ã©ãGã¯ããã«ãã³ã»ã°ã©ãã§ãããããšã瀺ããã.ï¿œ
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ãäŸé¡ 5.3 ã (2004幎床 æŒç¿åé¡ 5 )
1. æ¬è¬çŸ©ããŒãäžã«æãããå¬ãäŒå Žã®é è·¯åé¡ãã«ãããŠ(1)åäŒå Žéã®é¢ä¿ãè¡šãã°ã©ããæã.(2) (1)ã§æ±ãããªã€ã©ãŒã»ã°ã©ãã«ãããŠ, Fleuryã®ã¢ã«ãŽãªãºã ãçšããããšã«ãã, ãªã€ã©ãŒå°éãæ±ãã.
2. ãªã€ã©ãŒã»ã°ã©ãã§, ããç¹ vããåºçºããéãã¯, åã蟺ã 2床ãšéããªãããã«ããŠåæãªæ¹åã«èŸºããã©ãã°ãªã€ã©ãŒå°éãåŸããããšã, ãã®ã°ã©ãã¯ç¹ vããä»»æåšåå¯èœã§ãããšãã.
(1)å³ 5.94(å·Š)ã«äžããã°ã©ãã¯ä»»æåšåå¯èœã§ããããšã瀺ã.(2)ãªã€ã©ãŒã»ã°ã©ãã§ã¯ããã, ä»»æåšåå¯èœã§ã¯ãªãã°ã©ãã®äŸãäžã€æãã.(3)ä»»æåšåå¯èœãªã°ã©ããå±ç€ºäŒå Žã®èšèšã«åããŠããçç±ãè¿°ã¹ã.
3. å³ 5.94(å³)ã® Groetzsch ã°ã©ãã¯ããã«ãã³ã§ããããšã瀺ã.
(解çäŸ)
1. äŒå Žé 眮ãé£çµã°ã©ãã§è¡šã, Fleuryã®ã¢ã«ãŽãªãºã ãçšããããšã«ãã, å®éã«ãªã€ã©ãŒå°éãæ±ããŠã¿ãã.
(1)åé¡ã«äžããããè¡šã«åŸã£ãŠ aïœgã®äŒå Žãé 眮ãããšå³ 5.95(å·Š)ã®ããã«ãªã.(2) Fleuryã®ã¢ã«ãŽãªãºã ãçšããããšã«ãã, æãã¹ãå·¡åè·¯ãåŸããã. å³ 5.95(å³)ã«æããçµè·¯ããªã€ã©ãŒå°éãäžãã.
2.(1)å³ 5.96ã«ãããŠ, ç¹ v = 4ããåºçºãããšããŠ, 第äžæ©ã§ v â 1, v â 3, v â 5, vâ 7, vâ 8, v â 9ã®ç°ãªã 6éãã®ããããéžã¶ãã»ã»ã»ã»çã ã«ãã, ããšãªãçµè·¯ãåŸããã. å°ã é¢åã§ããã, å šãŠã®å¯èœãªçµè·¯ãæžãäžããŠã¿ããš (äŸãã°, äžçªç®ã®äžç·ãåŒãããçªå·ã«å¯Ÿå¿ããçµè·¯ãå³ç€ºã
ãã㯠87ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
v
1
2
3
4
5
6
7
8
9
å³ 5.94: ããã§ä»»æåšåå¯èœã§ããããšã瀺ãã°ã©ã (å·Š). å³å³ã¯ Groetzsch ã°ã©ã.
a
b
c
d
e
f
g
a
b
c
d
e
f
g
1
2
3
4
5
6
7
8
9
10 11
12
13
å³ 5.95: åäŒå Žéã®é¢ä¿ãè¡šãã°ã©ã (å·Š) ãšæ±ãããªã€ã©ãŒå°é (å³).
ããšå³ 5.97 ã®ããã«ãªã)
4123456748694 , 4123456749684, 4123456847694, 4123456849674
4123456947684 , 4123456948674, 4123476548694, 4123476549684
4123476845694 , 4123476849654, 4123476945684, 4123476948654
4123486547694 , 4123486549674, 4123486745694, 4123486749654
4123486945674 , 4123486947654, 4123496547684, 4123496548674
4123496745684 , 4123496748674, 4123496845674, 4123496847654
4321456748694 , 4123456749684, 4321456847694, 4123456849674
4321456947684 , 4123456948674, 4321476548694, 4123476549684
4321476845694 , 4123476849654, 4321476945684, 4123476948654
4321486547694 , 4123486549674, 4321486745694, 4123486749654
4321486945674 , 4123486947654, 4321496547684, 4123496548674
4321496745684 , 4123496748674, 4321496845674, 4123496847654
4567486941234 , 4567486943214, 4567496841234, 4567496843124
4567412348694 , 4567412349684, 4567432148694, 4567432149684
4568476941234 , 4987476943214, 4568496741234, 4568496743214
4568412347694 , 4568412349674, 4568432147694, 4568432149674
ãã㯠88ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
v
1
2
3
4
5
6
7
8
9
å³ 5.96: ããã§ä»»æåšåå¯èœæ§ã«ã€ããŠèå¯ããã°ã©ã.
12
34
5 6
7
8
9
10
11
12
å³ 5.97: äžç·ãåŒãããçªå·ã«å¯Ÿããå ·äœçãªçµè·¯.
4569476841234 , 4569476841234, 4569486741234, 4569486743214
4569412347684 , 4569412348674, 4569432147684, 4569432148674
4765486941234 , 4765486943214, 4765496841234, 4765496843124
4765412348694 , 4765412349684, 4765432148694, 4765432149684
4768456941234 , 4768456943214, 4768496541234, 4768496543214
4768412345694 , 4768412349654, 4768432145694, 4768432149654
4769456841234 , 4769456841234, 4769486541234, 4769486543214
4769412345684 , 4769412348654, 4769432145684, 4769432148654
4865476941234 , 4865476943214, 4865496741234, 4865496743124
4865412347694 , 4865412349674, 4865432147694, 4865432149674
4867456941234 , 4867456943214, 4867496541234, 4867496543214
4867412345694 , 4867412349654, 4867432145694, 4867432149654
4869456741234 , 4869456741234, 4869476541234, 4869476543214
4869412345674 , 4869412347654, 4869432145674, 4869432147654
4965476841234 , 4965476843214, 4965486741234, 4965486743124
4965412347684 , 4965412348674, 4965432147684, 4965432148674
4967456841234 , 4967456843214, 4967486541234, 4967486543214
4967412345684 , 4967412348654, 4967432145684, 4967432148654
4968456741234 , 4968456741234, 4968476541234, 4968476543214
4968412345674 , 4968412347654, 4968432145674, 4968432147654
ãã㯠89ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
以äž, å šéšã§ 144éãã®çµè·¯ (ãªã€ã©ãŒå°é)ãå¯èœã§ãã, åŸã£ãŠ, ãã®ã°ã©ãã¯ä»»æåšåå¯èœãªã°ã©ãã§ãã.
(2)å³ 5.98ã«ãã®äžäŸãäžãã. å³ 5.98ã®ã°ã©ãã¯åç¹ã®æ¬¡æ°ãå¶æ°ã§ãã, å®ç 6.2ãã, ãã®ã°ã©
v
1
2
3
4
5
6
7
8
9
10
11
å³ 5.98: ä»»æåšåãäžå¯èœã§ããã°ã©ãã®äžäŸ.
ãã¯ãªã€ã©ãŒã»ã°ã©ãã§ãã, 確ãã«ãªã€ã©ãŒå°é, äŸãã°, v â 3â 2â 1â v â 4â 5â 6â7â 4â 8â 9â 10â 11â 8â v.ããã, äŸãã°å³ 5.98ã®ç¢å°ã«ç€ºããéãã®é²è·¯ãéžã¶ãš, å³ã®ç¹ 8, 9, 10, 11ãããªããå€ç«ãããæåãçŸããŠããŸã. åŸã£ãŠ, ç¹ 8ã§ã®é²è·¯ã®éžæã«ãã£ãŠã¯, ãªã€ã©ãŒå°éãã§ããªããªã. ãã®æå³ã§, å³ 5.98ã«äžããã°ã©ãã¯ä»»æåšåäžå¯èœãªã°ã©ãã§ãããšèšãã.
ããŠ, ããã§ã¯, ä»»æã®ãªã€ã©ãŒã»ã°ã©ããäžãããããšããŠ, ãã®ã°ã©ããä»»æåšåå¯èœã, ãããã¯, äžå¯èœã§ããã, ãšããå€å®ã¯äžè¬ã«ã°ã©ãã®ã©ã®ãããªç¹åŸŽã«ãã£ãŠæ±ºãŸãã®ã§ãããã ?å³ 5.99 ã«å³ 5.98 ãšã¯ç°ãªãä»»æåšåäžå¯èœãªã°ã©ãã 2ç¹æãã. ãããã®ã°ã©ããèå¯ãããš,
4
3
2
v
1
v
1
2
3
4
5
6
7
å³ 5.99: äžã«ããããããã®ã°ã©ããä»»æåšåãäžå¯èœã§ãã.
ãããã次æ°ã 4以äžã®ç¹ã 2ç¹ä»¥äžå«ãŸããããšãããã. ãã, æ¬¡æ° 4以äžã®ç¹ã 2ç¹ä»¥äžå«ãŸããã®ã§ããã°, å³ 5.99 ã® 2(å·Šå³)ã 4ã®ããã«, ãã®ç¹ã«ãããŠ, å€ç«ããæåãçæãããŠããŸããããªçµè·¯ã®åãæ¹ã¯åžžã«å¯èœã§ãã. åŸã£ãŠ, ä»»æåšåãå¯èœã«ããããã«ã¯, æ¬¡æ° 4以äžã®ç¹ãäºã€ä»¥äžå«ãŸãªããããªãªã€ã©ãŒã»ã°ã©ããçšããããšãèèŠã§ãã.
(3)å±ç€ºå Žã§ã¯, 客ãåå±ç€ºå Žããä»»æã«æ¬¡ã®å±ç€ºå Žãéžã³, ããã, åå±ç€ºå Žãäžåãã€ãŸãã£ãŠ, æåã®å±ç€ºå Žã«æ»ã£ãŠãããããšãæãŸãã. åŸã£ãŠ, ãã®æ§è³ªãæºããä»»æåšåå¯èœã°ã©ãã®åé ç¹ã«å±ç€ºå Žãèšçœ®ããããšã, é©åãªå±ç€ºå Žã®èšèšã§ãã.
3. å³ 5.100ã«çããèŒãã. ãã®å³ 5.100㯠Ore ã®å®çã«ããããã«ãã³ã§ããããã®ååæ§ã¯æºãããŠã¯ããªãã (äŸãã° deg(7) + deg(10) = 3 + 4 = 7 < 11ã§æºãããªã), å³ 5.100ã«ããã«ãã³éè·¯ã瀺ããããã«ç¢ºãã«ããã«ãã³ã§ãã.
ãã㯠90ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
1
2
3
4
5
6
7
8
9
10
11
å³ 5.100: æ±ããã¹ãããã«ãã³éè·¯.
ᅵ
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ᅵ
ãäŸé¡ 5.4 ã (2005幎床 æŒç¿åé¡ 5 )
1. äºéšã°ã©ãGã«å¥æ°åã®ç¹ãããå Žå, Gã¯ããã«ãã³ã»ã°ã©ãã§ãªãããšã瀺ã.2. å³ã«ãããã°ã©ãã¯ããã«ãã³ã»ã°ã©ãã§ãªãããšã瀺ã.
(解çäŸ)
1. ãŸãã¯ç¹æ° n = 4ã®å Žåã®äºéšã°ã©ãã®äŸãå³ 5.101(å·Š)ã«èŒããã, ããã¯æããã«ããã«ãã³éè·¯ãå«ãã®ã§ããã«ãã³ã»ã°ã©ãã§ãã. 次㫠n = 6ã®å Žåã®äºéšã°ã©ãã®äžäŸãšãã®å圢ãªã°ã©ãã
n=4
n=6
å³ 5.101: n = 4 ã®å Žåã®äºéšã°ã©ãã®äŸ (å·Š). å³å³ã¯ n = 6 ã®å Žåã®äºéšã°ã©ãã®äžäŸ (äž) ãšãããšå圢ãªã°ã©ã (äž). éè·¯ãååšãã.
å³ 5.101(å³)ã«èŒããã, ãããæããã«ããã«ãã³éè·¯ãå«ãã®ã§ããã«ãã³ã»ã°ã©ãã§ãã. ããã 2ã€ã®äŸãããããããã«, äºéšã°ã©ããçœç¹ãšé»ç¹ã亀äºã«æ¥ãããã«éè·¯ã°ã©ããšããŠæããå Žåã«ã¯å¿ ãããã«ãã³ã»ã°ã©ãã«ãªã.äžæ¹, nãå¥æ°ã®å Žåã«ã¯å³ 5.102ã« n = 7ã®äŸã§ç€ºãããã«, ãã®ãããªçœ, é»ç¹ã®é 眮ã¯äžå¯èœã§ãã, å¿ ãéè·¯äžã«ã¯é»é», ãããã¯çœçœã䞊ãã§ããŸã. åŸã£ãŠ, äºéšã°ã©ãã¯ãã®ç¹æ°ãå¥æ°ã®å Ž
ãã㯠91ããŒãžç®
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n=7
å³ 5.102: n = 7 ã®å Žåã«ã¯äºéšã°ã©ããéè·¯ã§è¡šçŸããããšãã§ããªã.
åã«ã¯ããã«ãã³ã»ã°ã©ãã«ã¯ãªããªã.
2. ãŸã, åé¡ã«äžããããã°ã©ãã®äžå€®ã®ç¹ãé€å»ããã°ã©ããèãããš, ããã«ã¯ããã«ãã³éè·¯ãååšãã (å³ 5.103åç §). 以äžã®è°è«ã§ã¯ãããåºæºãšããŠèãã. ãŸã, 話ã®èŠéããè¯ããããã,ãã®éè·¯ãšå圢ãªã°ã©ããèããããšã«ããã (å³ 5.103ã®äžå³). åé¡ã®ã°ã©ãã¯ãã®ã°ã©ãã« 1ç¹
1 2
3 4
5
67
89
10
1112
1 2 3 4 5 6
789101112
1 2 3 4 5 6
789101112
13
å³ 5.103: åé¡ã«äžããããã°ã©ãã®äžå€®ã®ç¹ãé€å»ãããš, ããã¯ããã«ãã³ã»ã°ã©ãã§ããã«ãã³éè·¯ãååšãã (å·Š). åé¡ã«äžããããã°ã©ããšå圢ãªã°ã©ã (å³). ãã®ã°ã©ãã«ããã«ãã³éè·¯ããããåŠããèå¯ããã°ãã.
ãå ããŠ, ãã®ç¹ (13ãšããã) ãšå³ 5.103(å·Š)ã®ç¹ 2,4,6 ãšãçµãã§ã§ããã®ã§, ãããå ·äœçã«æããšå³ 5.103(å³)ã®ããã«ãªã. ããã§, ãã®ã°ã©ãã§ã¯ç¹ 13ã¯ç¹ 2,4,6 ãšç¹ 3,5 ã«ã1ã€é£ã°ããã§çµã°ããŠããããšãã, ç¹ 2 ãåºçºããŠ, ç¹ 3,4,5, åã³, ç¹ 13 ãçµç±ããŠç¹ 6 ã«è³ãããã«ã¯, å¿ ã, ç¹3ãç¹ 5 ã«ã¯ãšãŸããã«ééããªããã°ãªããªãããšã«æ³šç®ããã. ãŸã, ç¹ 2ãã 2 â 3 â 4 ãšé²
ãã§, ç¹ 9 ã«ç§»ã£ãå Žåã«ã¯, 9 â 8 ãšé²ããš, ãã以åŸéšåã°ã©ã {10, 11, 12} ã«ã¯é²ããªããªã, éã«, 9 â 8 ãžãšç§»ã£ãå Žåã«ã¯éšåã°ã©ã {6, 7, 8}ãžã¯é²ããªããªã.ãã®ããšããçŽã¡ã«å šãŠã®ç¹ã 1åãã€éã£ãŠå ã«æ»ãéè·¯ã¯ååšããªãããšããããã®ã§, ãã®ã°ã©ãã¯ããã«ãã³ã»ã°ã©ãã§ã¯ãªãããšã«ãªã. ãã¡ãã, ããã§èããçµè·¯ä»¥å€ã«ãç¹ 1 â ç¹ 12
â · · · ã®ããã«åãçµè·¯ãååšããã, çµå±, ããã§èãã, ç¹ {2, 3, 4, 5, 6, 13}ãå«ãã ãéšåã°ã©ããã«ã¶ã€ããã°äžèšã®åé¡ãçã, 決ããŠããã«ãã³éè·¯ãæãããšã¯ã§ããªãããšã«ãªã.
â» è£è¶³èª¬æ
Oreã®å®çã¯ããã«ãã³ã»ã°ã©ãã§ããããã®ååæ¡ä»¶ã§ãããã, Oreã®å®çãæºãããŠããã°, ã€ãŸã,å®å šã°ã©ãã®ããã«ååãªèŸºæ°ãããã°, ããã«ãã³éè·¯ãããããšã瀺ããã, Oreã®å®çãæºãããªãå Žå, äžè¬çã«èšã£ãŠããã«ãã³ã»ã°ã©ããåŠãã蚌æããããšã¯ãšãŠãé£ãããªã. ãã®æã®ãå€å®åé¡ãã§ã¯éå®ã«ãªãå¿ èŠæ¡ä»¶ãããã€ãããããã ã, ããã¯ååæ¡ä»¶ãšæ¯ã¹ãŠæ°ãå°ãªã, å®çšçãªãã®ããã»ã©ç¡ãããã§ãã. å¿ èŠååæ¡ä»¶ã«ã€ããŠã¯ãŸã äœãèŠã€ãã£ãŠããªã.
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åŸã£ãŠ, ããã«ãã³ã»ã°ã©ããåŠãã®èšŒæã¯ã°ã©ãã®ç¹æ§ã«å¿ããŠã±ãŒã¹ã»ãã€ã»ã±ãŒã¹ã§åãçµãŸãªããã°ãªããªãã, ãããŸãã«èšãã°, ãŸãããã£ãŠã¿ã䟡å€ã®ããæ¹æ³ã¯ 2ã€ãã, äžã€ã¯äžã®äŸé¡ã§çŽ¹ä»ãããã°ã©ããäºéšã°ã©ãã§è¡šã, ãã®ç¹æ°ãå¥æ°ã§ããããšã§éããã«ãã³æ§ã瀺ããããæ¹ (æ¹æ³ 1).ããäžã€ã¯èŸºæ°ã«é¢ããŠèçæ³ã§ççŸãå°ããšããæ¹æ³ (æ¹æ³ 2)ã§ãã.ããã§ã¯ç°¡åã«æ¹æ³ 2ã説æããŠãããã. ãŸã, äŸãšããŠå³ 5.104ã®ãããªç¹æ° 11, èŸºæ° 15ã®ã°ã©ã
ã«å¯Ÿã, ãããã«ãã³éè·¯ C ãååšããããšä»®å®ãã. ãã®éè·¯ C äžã§ã¯åç¹ã«ã¯å¿ ã 2æ¬ã®èŸºãæ¥ç¶ã
1 2
3
4
5
67
8
910
11
12
13
14
15
a
b
c
d
e
å³ 5.104: èçæ³ãçšããŠéããã«ãã³ã°ã©ãã§ããããšã瀺ãã®ã«äŸãšããŠçšããã°ã©ã.
ãŠããªããã°ãªããªãããšã«æ³šç®ãããš, äºãã«é£æ¥ããŠããªã a, b, c, d, åã³, eã® 5ç¹ã®ããããã®æ¬¡æ°ã¯ 3, 3, 4, 3, 3 ã§ããã®ã§, C äžã«ç¡ã蟺æ°ã¯å°ãªããšã (3â 2) + (3â 2) + (4â 2) + (3â 2) + (3â 2) = 5(æ¬)ã§ãã, åŸã£ãŠ, éè·¯ C ã«ã¯é«ã 15â 5 = 10 (æ¬) ãã蟺ãç¡ãããšãããã. ããã, ç¹æ° 11ã§ããã«ãã³éè·¯ãäœãå Žåã«ã¯ãã®éè·¯ã®èŸºæ°ã¯ 11ãšãªãã®ã§, èŸºæ° 10ã§ã¯ããã¯äžå¯èœãšããããšã«ãªã,æã ãçšãããããã«ãã³éè·¯ãååšããããšããä»®å®ã«ççŸãçããã®ã§å³ 5.104ã®ã°ã©ãã«ã¯ããã«ãã³éè·¯ãç¡ã, ãšçµè«ä»ããããšãã§ãã.ï¿œ
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ãäŸé¡ 5.5ã (2006幎床 æŒç¿åé¡ 5 )
Gã¯ããã«ãã³ã»ã°ã©ãã§ãããšã, S㯠Gã® kåã®ç¹ãããªãä»»æã®éåã§ãããšãã. ãã®ãšã, ã°ã©ã G â S (Gãã Sã®ç¹ãšãããã«æ¥ç¶ããŠãã蟺ãå šãŠé€å»ããŠåŸãããã°ã©ã)ã®æå㯠kå以
äžã§ããããšãå ·äœçãªããã«ãã³ã»ã°ã©ãã«å¯ŸããŠäžã€äŸç€ºãã.
(解çäŸ)
ããã«ãã³ã°ã©ãã¯ããã«ãã³éè·¯ãå«ã¿, ãã®éè·¯ Cã¯ââãäºãéãã«äžŠã¹ãŠã§ãã茪ã§ãããã, å®å šäºéšã°ã©ãKs,sã§è¡šãããšãã§ãã (s = 2, 3, · · ·). åŸã£ãŠ, Gã¯ãã®éè·¯ãæ§æãã蟺ãšä»ã®æ¥ç¶èŸºã
ããªãå³ 5.105ã®ãããªã°ã©ãã§ãããšèããŠãã. ããã§, Gã®äžããä»»æã® kåã®ç¹ãåãåºããŠæ§æ
ãããéå Sã GããåŒããŠã§ããã°ã©ãã®æåæ°ã¯, kåã®ç¹ãå šãŠé£æ¥ããå Žåã«ã¯æããã« 1ã§ãã, ããã Gâ Sã®æåæ°ã®æå°å€ãäžãã (å³ 5.106åç §). ããã, ããã§åé¡ãšããã®ã¯ Gâ Sã®æå
ã®æ倧å€ã§ãã. ãã®æ倧å€ãäžãããããªéå Sã®éžã³æ¹ã¯æããã« Sãæ§æãã kåã®ç¹ãå šãŠé£æ¥
ããªãå Žåã§ãããã, ãã®å Žåã® Gâ Sã®æåæ°ãè©äŸ¡ããã°ãã. ãã®ããã«, éè·¯ Cäžã® kåã®ç¹ã
ã 2ã€ãã€çµãã§ãã¢ã«ã (ãããããã¢ã®ç·æ°ã¯ l = k/2), Cäžã«ãã®ãã¢ãäžã€ã§ããããšã« Gâ Sã®
æåãã©ã®ããã«å€åããŠããã®ãã調ã¹ã. ãããšå³ 5.107(å·Š)ãåèã«ããèå¯ãã, ãã¢æ°ã 1ã®å Žåã«ã¯æåæ°ã¯ 2, ãã¢æ°ã 2ã®å Žåã«ã¯æåæ°ã 4, ...., ãã¢æ°ã lã®å Žåã«ã¯æåæ°ã 2lãšãªã, ãã® 2l
ãã㯠93ããŒãžç®
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C
G
å³ 5.105: ããã§èããããã«ãã³ã°ã©ã. éè·¯ C ãããã§ã®ããã«ãã³éè·¯.
k=1
S
å³ 5.106: S ã®èŠçŽ ãå šãŠé£æ¥ããå Žåã®äŸ. å®ç·ã®éšåã§ã°ã©ã G ãåæããããšã«ãªã, åŸããã G â S ã®æåæ°ã¯æããã«1 ã§ãã.
㯠Sã®ç¹ã®ç·æ° k ã§ãã£ããã, çµå±
Gâ S ã®æåæ° â€ k
ãšãªã, é¡æãæºããããšã«ãªã. ãšããã§äžèšã®è°è«ã§ã¯ Gã®äžã®éè·¯ Cã«é¢ããŠèã, ãã®éè·¯ãæ§æãã蟺以å€ã®æ¥ç¶èŸºãã²ãšãŸãã¯èããªãã£ãããã ã, å³ 5.107(å³)ã®ãããªæ¥ç¶èŸºãå ãã£ããšããŠã,Gâ Sã®æåæ°ã¯æžãããã¯ããã, 決ããŠå¢ããããšã¯ãªã. ãã£ãŠ, ãã®å Žåã«ãé¡æã¯æºããããããšã«ãªã.ï¿œ
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ãäŸé¡ 5.6 ã (2005幎床æ å ±å·¥åŠæŒç¿ II(B) #1)
K3,K5,K7, ããã³K9 ã«ã¯ããã«ãã³éè·¯ãããããšã Oreã®å®çã«ãã瀺ã, ããããã®ã°ã©ãã«ãããŠ, äºãã«å ±éãªèŸºãæããªã â èŸºçŽ ãªâ ããã«ãã³éè·¯ãããã€ãããã調ã¹ã. ã€ãã§, ãã®çµæãäžè¬åã, K2k+1 (k ⥠1)ã®èŸºçŽ ãªããã«ãã³éè·¯æ°ãæ±ããå ¬åŒãäœã (é¡æšã«ãã£ãŠå ¬åŒãæ±ããå Žåã«ã¯ãã®æ£åœæ§ã蚌æããããš).
(解çäŸ)
ãŸã, å®å šã°ã©ãã«ããã«ãã³éè·¯ãååšããããšã¯, äžè¬ã®Kn ã«å¯ŸããŠç€ºãã. Kn ã®å šãŠã®ç¹ã®æ¬¡æ°
㯠nâ 1ãªã®ã§, nâ 1 + nâ 1 = 2nâ 2 ⥠n (n ⥠3) ãªã®ã§, Oreã®å®çãæºããããšã¯æããã»ã»ã»ãšãªãããã§ããã, å®ã¯Oreã®å®çã®æ¡ä»¶åŒ : deg(v) + deg(u) ⥠nã®ç¹ u, vã¯ãäºãã«é£æ¥ããªãç¹ãã§ãã
ã®ã§, å®å šã°ã©ãã¯å šãŠã®ç¹ãé£æ¥ããŠããããã§ãããã, ããããã®ãŸãŸé©çšããããšã¯ã§ããªã.ããã§, Oreã®å®çãæžãæããã. ãã°ã©ãã«å«ãŸããä»»æã®ç¹ vã®æ¬¡æ°ã f(n)以äžã§ãããã€ãŸã,
deg(v) ⥠f(n)ãšä»®å®ãã. ããã§, f(n)㯠nã®é¢æ°ã§ãã. ãã®ãšã, ç¹ uã«ã€ããŠããããæãç«ã€ã¹
ããªã®ã§, deg(u) ⥠f(n). ãã® 2ã€ã®äžçåŒã®èŸºã ã足ããš deg(v) + deg(u) ⥠2f (n)ã§ããã, ãããš
ãã㯠94ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
1
2
3
4
1
2
3
4
å³ 5.107: S ã®æåãå šãŠé£æ¥ããªãå Žåã§, |S| = 4 ã®å Žå. åŸããã G â S ã®æåæ°ã¯ 4 ã§ãã. ãŸã, ããã«ãã³éè·¯ãæ§æãã蟺以å€ã«æ¥ç¶èŸºãã§ãããšããŠã, ãã®æåæ°ã¯æžãããã¯ããã, 決ããŠå¢ããªã (å³å³).
Oreã®å®çã®æ¡ä»¶åŒãæ¯èŒãããš, 2f (n) = n, ã€ãŸã, f(n) = n/2ã§ããããšãããã. åŸã£ãŠ, Oreã®å®çã¯æ¬¡ã®ããã«èšãçŽãããšãã§ãã.ã°ã©ãã«å«ãŸããå šãŠã®ç¹ã«å¯Ÿã
deg(v) ⥠n
2(5.132)
ãæç«ãããªãã°, ãã®ã°ã©ãã¯ããã«ãã³ã»ã°ã©ãã§ãã. ãããDirac (ãã£ã©ãã¯)ã®å®çãšåŒãã§
ãã. ä»ã®å Žåå šãŠã®ç¹ã®æ¬¡æ°ã¯ nâ 1ã§ãããã, n ⥠3ã§ããã°ãã®æ¡ä»¶ãæºãã. åŸã£ãŠ, ããã«ãã³éè·¯ã¯ååšãã.
åŸåã®éšåã¯å ·äœçã«äºãã«èŸºçŽ ã¯ããã«ãã³éè·¯ãèŠã€ããã¢ã«ãŽãªãºã ãäžããŠããŸãã. ãŸã, å®å šã°ã©ãã®æãæ¹ãšã㊠n (å¥æ°)åã®ç¹ãéè·¯ã°ã©ããšãªãããã«é 眮ãã. ãããŠ, åç¹ãèªå以å€ã®ç¹ãšçµãã§ããããã«ããŠå®å šã°ã©ãKnãæãããšã«ãã (å³ 5.108åç §). ãã®ãšã, åºçºããç¹ vãé©
åœã«éžã¶ãš, 1åç®ã®ããã«ãã³é路㯠vããéè·¯ã°ã©ãã®å€åšããã©ã, vã«æ»ãããšã«ããåŸããã. 2åç®ã¯ vãã 1ã€é£ã³ã«é 次ç¹ããã©ã£ãŠãã, vã«æ»ãããšã«ããåŸããã. 3åç®ã¯ vãã 2ã€ãšã³ã«é 次åã vã«æ»ãããšã«ãã, 4åç®ã¯ vãã 3ã€ãšã³ã«é 次åãã»ã»ã»ãšããããã«ããŠåŸãããããã«ãã³éè·¯ã¯å šãŠäºãã«èŸºçŽ ãªãã®ãšãªãããšã¯æããã§ãã. ãã®ãããªç¹ vããåŒãç¶ãç¹ã®éžæã®äœå°
ãšããŠã¯ (nâ 1)/2éãã ãååšãã ( ç¹ vã®æ¬¡æ°ã®åå. ãªãååã«ãªãã, ã¯æ®ãã®ååã¯å šãŠã®éè·¯ãéåãã«ãã©ãããšã«çžåœããã®ã§, ãç¡åãããã«ãã³éè·¯ããšããŠã¯åäžèŠãã) ã®ã§, n = 2k + 1ã®å Žåã«ã¯ (2k + 1 â 1)/2 = kéããšãªã, åŸã£ãŠ, å®å šã°ã©ãK2k+1 ã®äºãã«èŸºçŽ ãªããã«ãã³éè·¯ã®
åæ°ã¯ kã§ããããšãããã£ã. å³ 5.108ã«K3,K5, ããã³, K7ã®å Žåã®äºãã«èŸºçŽ ãªããã«ãã³éè·¯ã
å³ç€ºãã.
ããã, ããã§æ³šæããªããã°ãªããªãã®ã¯, 2k + 1ã 1ãšèªåèªèº«ä»¥å€ã®çŽæ°ãæã€å Žå, ãã®ãçŽæ°åé£ã³ãã§éè·¯ãæããŠãããš, å šãŠã®ç¹ãå·¡ãåã«éããã°ã©ããã§ããŠããŸã (å³ 5.109åç §). åŸã£ãŠ,ãã®å Žåã«ã¯äºãã«èŸºçŽ ãªã°ã©ãã®åæ°ã¯ kãã 2k+ 1ã®çŽæ°ã®åæ° k
â²ãåŒãããã®ã«ãªã. åŸã£ãŠ, äº
ãã«èŸºçŽ ãªããã«ãã³éè·¯ã®åæ°ãM(K2k+1)ãšãããš
M(K2k+1) =
{k (2k + 1ãçŽ æ°ã®ãšã)
k â kâ²(2k + 1ãçŽ æ°ã§ãªã, 1ãšèªåèªèº«ä»¥å€ã« k
â²åã®çŽæ°ãæã€ãšã)
(5.133)
ãšãŸãšããããšãã§ãã.
ãã㯠95ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
K3
K5
K7
å³ 5.108: K3, K5, K6 ã®äºãã«èŸºçŽ ãªããã«ãã³éè·¯.
NG !
K9
å³ 5.109: K9 ã®äºãã«èŸºçŽ ãªããã«ãã³éè·¯. 9 ã®çŽæ° 3 é£ã³ã§åç¹ãçµãã§ãããš, ããã«ãã³éè·¯ãã§ããåã«éããã°ã©ããåºæ¥äžãã£ãŠããŸã.
ᅵ
ᅵ
ãäŸé¡ 5.7 ã (2005幎床æ å ±å·¥åŠæŒç¿ II(B) #1)
ããŒã¿ãŒã¹ã³ã»ã°ã©ããããã«ãã³ã»ã°ã©ãã§ãªãããšã蚌æãã.
(解çäŸ)
å³ 5.110ã®ããã«ããŒã¿ãŒãœã³ã»ã°ã©ãã®åç¹ã«ååãã€ãã. ãŸãçç®ããã®ã¯, u1, u2, · · · , u5ã® 5ç¹ãããªãå éšã®éšåã°ã©ã (g1 ãšåã¥ãã) ã¯ãæåã®äžçæžãããšããŠããã«ãã³éè·¯ãååšããããšã§ãã. åŸã£ãŠ, å€åš (éšåã°ã©ã g2 ãšåã¥ãã) ã® 1ç¹ (v1 ãšããŠäžè¬æ§ã倱ããªã) ããåºçºã, æåéšåã°ã©ã g1ã®äžéšãçµç±ã, ç¹ v1ã«æ»ããšãã, g1ãš g2ã 2ã€ã®èŸºã§çµã°ããå Žå (ã±ãŒã¹AãšåŒãŒã)ãš, v1ããåºçºã, g1ã®äžéšãçµç±, g2ã«è³ã, ããã« g1ã®äžéšãçµç±ã㊠v1ã«æ»ããšãã, g1ãš g2ã 4æ¬ã®èŸºã§çµåãããå Žå (ã±ãŒã¹BãšåŒã¶) ã®ããããã§ãã. åŸã£ãŠ, 以äžã§ã¯ãã®åã ã®ã±ãŒã¹ã«å¯Ÿã,ããã«ãã³éè·¯ãååšããªãããšã瀺ããŠãã.
⢠(ã±ãŒã¹A)g1ãš g2 ãçµã¶èŸºã v1u1 ãšä»»æã® eãšãã. ãã®ãšã, v1u1, e ãå«ãéãšããŠã¯æ¬¡ã® 2ã€ãèãããã.(1) e = u4v4 ã®ãšã, ãã®é㯠v1u1u3u5u2u4v4. ãã®ãšã, æ®ãç¹ã¯ v2, v3, v5.(2) e = u3v3 ã®ãšã, ãã®é㯠v1u1u4u2u5u3v3. ãã®ãšã, æ®ãç¹ã¯ v2, v4, v5.
ãã㯠96ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
v1
v2
v3v4
v5
u1
u2
u3u4
u5
å³ 5.110: ããŒã¿ãŒã¹ã³ã»ã°ã©ãã®åç¹ã«ååãã€ãã.
ã§ãã. ä»¥äž (1)(2)ã®ãããã®å Žåãæ®ã 3ã€ã®ç¹ãéã£ãŠ v1 ã«æ»ããªãããšã¯æãã. ãã£ãŠ,(ã±ãŒã¹A)ã§ããã«ãã³éè·¯ãååšããããšã¯ãªã.
⢠(ã±ãŒã¹B)
g1ãš g2ãšãçµã¶ 4ã€ã®èŸºã {v1u1, v2u2, v3u3, v4u4} ãšããŠãäžè¬æ§ã倱ããªã. ãã®ãšã, v5u5 ã¯
å«ãŸããªãããšã«ãªã. ããã§, ãã®å Žåã«ããã«ãã³éè·¯Cãååšãããšä»®å®ããã. ãããš, ããŒã¿ãŒã¹ã³ã»ã°ã©ãã®åç¹ã¯å¿ ã 2ã€ã®èŸºãšæ¥ç¶ããŠããªããã°ãªããªãããšã«ãªãã®ã§, ãããèæ ®ã«å ¥ãããš, C ã«ã¯ v1v5, v5v4 ãå«ãŸããããšã«ãªã. åŸã£ãŠ, ãã®ãšãã«ç¹ u4ã«çç®ãããš, u4u1
ãšãã蟺ã¯Cã«ã¯å«ãŸããªãããšã«ãªã. ãªããªãã°, u4u1ãååšãããšãªããš, ç¹ u1ã§ã¯ (æ¢ã« v1
ãšçµã°ããŠããã®ã§) ãããªã蟺ãçµã¶ããšã¯ã§ãã, ããã«ãã³éè·¯ãäœãããšã¯ã§ããªã. åŸã£ãŠ, v4 㯠u2 ãšçµã°ããã¹ãã§ããã, u2 㯠v2 ãšæ¢ã«çµã°ããŠããã®ã§, u2u5㯠C ã«å«ãŸããªãã
ãšã«ãªã. ããã, ãããªããšç¹ u5ã«ã¯ 1蟺 u5u3ã®ã¿ãæ¥ç¶ãããããšã«ãªã, ããã§ã¯æããã«CãååšããããšãšççŸãã. åŸã£ãŠ, (ã±ãŒã¹B) ã®å Žåã«ãããã«ãã³éè·¯ãååšããããšã¯ã§ã
ãªã.
以äžã®èå¯ã«ãã, ããŒã¿ãŒã¹ã³ã»ã°ã©ãã«ã¯ããã«ãã³éè·¯ãç¡ã, ã€ãŸã, ããŒã¿ãŒã¹ã³ã»ã°ã©ãã¯ããã«ãã³ã»ã°ã©ãã§ã¯ãªããšçµè«ä»ãããã.
ᅵ
ᅵ
ãäŸé¡ 5.8 ã (2006幎床æ å ±å·¥åŠæŒç¿ II(B) #1)
ç¹æ° nãå¶æ°, 蟺æ°mãå¥æ°ã®ãªã€ã©ãŒã»ã°ã©ãã¯ååšãããåŠã. çç±ãšãšãã«è¿°ã¹ã.
(解çäŸ)
ããããå šãŠã®ç¹ã®æ¬¡æ°ãå¶æ° (= 2)ã§ããç¹æ° 3(äžè§åœ¢)ãš 4(åè§åœ¢)ã®ã°ã©ããå³ 5.111 ã®ããã« 1ç¹(以åŸ, å ±æç¹ãšåŒã¶)ã§æ¥ç¶ããããš, ç¹æ°ã¯ 3 + 4 â 1(å ±æç¹åãå·®ãåŒã) = 6, èŸºæ° 3 + 4 = 7ãšãªãã®ã§, 蟺æ°ãå¥æ°, ç¹æ°ãå¶æ°ãšãªãé¡æãæºãã. ãã®ã°ã©ãã¯å ±æç¹ã®æ¬¡æ°ã 4, ãã以å€ã 2ãªã®ã§å šãŠå¶æ°ã§ãã. åŸã£ãŠ, ãªã€ã©ãŒã®å®çãã, ãã®ã°ã©ãã¯ãªã€ã©ãŒã»ã°ã©ãã§ãã. ãã£ãŠ, 蟺æ°ãå¥æ°,ç¹æ°ãå¶æ°ã§ãããããªãªã€ã©ãŒã»ã°ã©ãã¯ååšãã.
ãã㯠97ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
å³ 5.111: ããã§èããã°ã©ã. ããã¯ãªã€ã©ãŒã»ã°ã©ãã§ãã.
ᅵ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 5.9 ã (2007幎床 æŒç¿åé¡ 5 )
1. æ°å: D = (d1, d2, · · · , dn), d1 ⥠d2 ⥠· · · ⥠dn ãäžããããé, ãã®æ°åDãã°ã©ãçã§ãããåŠ
ãã®å€å®æ¡ä»¶ãšããŠæ¬¡ãç¥ãããŠãã. ããªãã¡ãæ°åDãã°ã©ãçã§ããã®ã¯, ãã®æ°åã®ç·å:
âni=1 diãå¶æ°ã§ãã, k = 1, 2, · · · , nã«å¯Ÿã
kâi=1
di †k(k â 1) +nâ
i=k+1
min(k, di) (5.134)
ãæç«ãããšã, ãã€, ãã®ãšãã«éã.ãããã§, èšå·: min(a, b)㯠a, bã®ãã¡ã§å°ããæ¹ãæå³ãããã®ãšãã.ãã®å€å®æ¡ä»¶ãçšããŠæ¬¡ã®æ°å:
⢠D1 = (3, 2, 2, 1)
⢠D2 = (4, 3, 3, 3, 3)
⢠D3 = (7, 6, 6, 6, 5, 5, 2, 1)
ã®ãããããã°ã©ãçãåŠããå€å®ãã.(â» äžèšå€å®æ¡ä»¶ã®èšŒæã¯äœè£ã®ããè ã¯èããŠã¿ããšè¯ã. ã¬ããŒãã«æžããŠãããå Žåã«ã¯, ãã®åå ç¹ãã. 蚌æäŸã¯æ¬¡å (5/28)é åžã®è¬çŸ©ããŒãã§è§£èª¬ãã.)
2. å®å šã°ã©ãKm ã®ç¹ãšKnâ2m ã®ç¹ãå šãŠçµã³, Km ã®ç¹ãšKm ã®ç¹ãå šãŠçµã¶ããšã«ãã£ãŠã§ã
ãã°ã©ãã Cm,n ãšåã¥ããã. (n > 2mã§ãã, Km ã¯Kmã®è£ã°ã©ãã§ãã.)ãã®ãšã
⢠Cm,n ã®èŸºæ° ε(Cm,n)ãm,nã§è¡šã.
⢠ε(Cm,n) ãæå°ãšããmã®å€ã nãçšããŠè¡šã, ãã®æå°å€ã nã®é¢æ°ãšããŠæ±ãã.
(解çäŸ)
1. æ¢ã«èŠãäŸé¡ 2.7 ã§ã¯äžããããæ°åãã°ã©ã Gã®æ¬¡æ°åãšãªããããªç¶æ³, ã€ãŸããã°ã©ãçããåŠãã調ã¹ãŠããã£ã. äžè¬çã«äžããããã°ã©ãã®æ¬¡æ°åãæžãåºãããšã¯æããã, éã«å ·äœçãªæ°åãäžããããå Žå, ãããã°ã©ãçã§ãããã©ãããå€å®ããããšã¯é£ãã. ããã§, ä»åã®æŒç¿åé¡ã§ã¯ GãåçŽã°ã©ãã§ããå Žåã«å¯Ÿããå€å®æ¡ä»¶ãå ·äœçã«ããã€ãã®æ°åã«å¯ŸããŠèª¿ã¹ãŠã
ãã£ã.ãŸãã¯ç¹æ°ã®å°ãªãç°¡å㪠D1 = (3, 2, 2, 1) ã«å¯ŸããŠæ¡ä»¶åŒã®æç«ã確ãããŠã¿ã. d1 = 3, d2 =
ãã㯠98ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
2, d3 = 2, d4 = 1ã§ãããã,â4
i=1 di = 8ã§ããå¶æ°. ãŸã, k = 1ã®å Žåã«ã¯ i = 2, 3, 4ã«å¯ŸããŠmin{1, di} = 1 ã§ãããã
1âi=1
d1 = 3 †1 · (1â 1) + 1 + 1 + 1 = 3
ãšãªã, æç«. k = 2, 3, 4ã®å Žåãåæ§ã«ããŠ
2âi=1
di = 5 †2 · (2â 1) + 2 + 1 = 5
3âi=1
di = 7 †3 · (3â 1) + 1 = 7
4âi=1
di = 8 †4 · (4â 1) = 12
ãšãªã, åé¡ã«äžããããäžçåŒãå šãŠã® kã«ã€ããŠæç«ãã. åŸã£ãŠ, æ°å D1 = (3, 2, 2, 1)ã¯ã°ã©ãçã§ãã. å®éã«ã°ã©ããæããŠã¿ããšå³ 5.112ã®ããã«ãªã.
V1V1
V1
å³ 5.112: 次æ°åãD1 = (3, 2, 2, 1)ã§äžããããã°ã©ã. é¡æã«äžããããäžçåŒã®èšŒæãè¡ããã,ã°ã©ãã |V1| = k, |V2| = nâkã®éšåã«åãã. å·Šããå³ãž, |V1| = 1, 2, 3 ã®å Žå.
ãã®äŸãå ·äœçã«ã¿ãããšã§, ããçšåºŠã¯æããã€ããã ã®ã§èšŒæãè©Šã¿ãã. ãŸãã¯å³ 5.112ã®ããã«èããã°ã©ãã |V1| = k, |V2| = nâ kã® 2ã€ã®ç¹éåã«åãã. ã€ãŸã, 蚌æãã¹ãäžçåŒã®å·ŠèŸºã«çŸããå
âki=1 di ãæ§æããç¹éåã V1, æ®ãã V2ãšããããã§ãã. ãããšäŸãã°, å³ 5.112 ã®
ã°ã©ãããã解ãããã«, V1 ãããªãéšåã°ã©ãã®æ¬¡æ°âk
i=1 di 㯠V1 ã«å±ãã蟺ãæ¥ç¶èŸºããã®å¯
äžã«ãããã®ãš, V1 ã®åç¹ãž V2 ã®åç¹ããåããæ¥ç¶èŸºããã®å¯äžã«ãããã®ã«åããããšãã§ã
ã. åè ã®èŸºæ°ã ε1, åŸè ã®èŸºæ°ã ε2ãšåã¥ããã. ãã®ãšã V1 ã®æ¬¡æ°ãš ε1, ε2ã®éã«ã¯, ε1ã«é¢ããŠã¯ãæ¡æè£é¡ããæãç«ã€ããšãèæ ®ããã°
kâi=1
di = 2ε1 + ε2 (5.135)
ãªãé¢ä¿ãæãç«ã€ããšãããã. ãã㧠V1 ã®äžã®èŸºæ°ã®äžéã¯æããã«éšåã°ã©ã V1 ããå®å šã°
ã©ãããšãªãå Žåã§ãã, ε1 †kC2 = k(k â 1)/2ã§ãã. ãã£ãŠ, (5.135)åŒã¯
kâi=1
di †k(k â 1) + ε2 (5.136)
ãšæžãæããããšãã§ãã. ããšã¯èŸºæ° ε2ãè©äŸ¡ã§ããã°ããã, V2ãã V1ãžã®æ¥ç¶èŸºã¯ V2ã®äžã®
1ç¹ (ãããç¹ iãšããã)ãã V1ã®å šãŠã®ç¹ãžãšæ¥ç¶èŸºã䌞ã³ãå Žåã«ã¯ kæ¬, V1ã®äžã®éšåéåã®
ã¿ã«æ¥ç¶èŸºã䌞ã°ãå Žåã«ã¯ç¹ iã®æ¬¡æ° diæ¬ã ãååšããããšã«ãªãã®ã§, ãã® 2ã€ã®å ŽåããŸãšããŠæžãã°, ç¹ iã®æ¥ç¶èŸºã¯min{k, di}ãšãªã. åŸã£ãŠ, ããã§åé¡ãšããèŸºæ° Îµ2㯠iã«é¢ããŠmin{k, di}
ãã㯠99ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ã i = k + 1ãã nãŸã§è¶³ãäžããân
i=k+1 min{k, di}ã«çãã. åŸã£ãŠ (5.136)åŒã¯çµå±
kâi=1
di †k(k â 1) +nâ
i=k+1
min{k, di} (5.137)
ãšæžãçŽã, ãããšæ¡æè£é¡ããä»»æã®ã°ã©ã Gã«å¯ŸããŠæãç«ã€ã¹ãæ¡ä»¶:ân
i=1 di = 2ε(G) =å¶æ°ãããããŠé¡æã«äžããããæ¡ä»¶åŒã瀺ããã. ããã«ç€ºããã°ã©ãçã§ããããã«æ°åã«èª²ããããæ¡ä»¶11 㯠Erdos-Gallaiã®å®çãšããŠç¥ãããŠãã.ãã®å®çã䜿ã£ãŠæ°å D2, D3 ãã°ã©ãçãã©ãããå€å®ããã. D2 = (4, 3, 3, 3, 3) ã«é¢ããŠã¯,d1 = 4, d2 = 3, d3 = 3, d4 = 3, d5 = 3ã§ãã,
â5i=1 di = 16ã§å¶æ°. k = 1ããé次äžçåŒã®æç«ã
ãã§ãã¯ããŠãããš
1âi=1
di = 4 †1 + 1 + 1 + 1 = 4
2âi=1
di = 7 †2 · (2â 1) + 2 + 2 + 2 = 7
3âi=1
di = 10 †3 · (3â 1) + 3 + 3 = 12
4âi=1
di = 13 †4 · (4â 1) + 3 = 15
5âi=1
di = 16 †5 · (5â 1) = 20
ãšãªã, å šãŠã® kã«å¯ŸããŠæç«ãã. åŸã£ãŠæ°åD2ã¯ã°ã©ãçã§ãã. å®éã«ã°ã©ããæããšå³ 5.113ã®ããã«ãªã.
4
3
3
3
3
å³ 5.113: 次æ°å D2 = (4, 3, 3, 3, 3) ãæã€ã°ã©ã.
æåŸã«æ°å D3 = (7, 6, 6, 6, 5, 5, 2, 1)ãå€å®ãã. d1 = 7, d2 = 6, d3 = 6, d4 = 6, d5 = 5, d6 = 5, d7 =2, d8 = 1ã§ãããã,
â8i=1 di = 38ãšãªã£ãŠå¶æ°. ãŸã, æ¡ä»¶åŒã®æç«ã k = 1ããé次確ãããŠã
ããš
1âi=1
di = 7 †1 + 1 + 1 + 1 + 1 + 1 + 1 = 7
2âi=1
di = 13 †2 · (2â 1) + 2 + 2 + 2 + 2 + 2 + 1 = 13
11 ãã®æ¡ä»¶ã¯å¿ èŠååã§ãã. ååæ§ã®ãã§ãã¯ãããã§ã¯çç¥ãã.
ãã㯠100ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
3âi=1
di = 19 †3 · (3â 1) + 3 + 3 + 3 + 2 + 1 = 18
4âi=1
di = 25 †4 · (4â 1) + 4 + 4 + 2 + 1 = 23
5âi=1
di = 30 †5 · (5â 1) + 5 + 2 + 1 = 28
6âi=1
di = 35 †6 · (6â 1) + 2 + 1 = 33
7âi=1
di = 37 †7 · (7â 1) + 1 = 43
8âi=1
di = 38 †8 · (8â 7) = 56
ãšãªã, k = 3, 4, 5, 6ã«å¯ŸããŠäžçåŒã¯æºããããªã. åŸã£ãŠD3ã¯ã°ã©ãçã§ã¯ãªã12 .2. ç°¡åãªã®ã§æçã«æžãã. åé¡ã® Cm,n ã®èŸºã®æ°ã¯å®å šã°ã©ãã®èŸºæ°ãã©ã®ããã«äžããããã®ãã
æãåºããŠ
ε(Cm,n) = m2 +m(mâ 1)
2+m(nâ 2m) +
(nâ 2m)(nâ 2mâ 1)2
=32
{m+
13
(12â n
)}2
â 16
(12â n
)2
+n(nâ 1)
2(5.138)
åŸã£ãŠ, ε(Cm,n)ãæå°ã«ããmã®å€ã¯
m =n
3â 1
6(5.139)
ã§ãã, ãã®ãšãã®æå°å€ã¯ n(n â 1)/3 â 1/24ãšãªã. ãã ã, m,nã¯æŽæ°ã§ããã¹ããªã®ã§, nãäžããããå Žåã®æå°å€ãäžããm㯠(5.139)ã«æãè¿ãæŽæ°å€ãšãªã.
12 ãG ã¯åçŽã°ã©ããã§ãããšããæ¡ä»¶ãç·©ãããš, ãã®æ°å D3 ã¯ã°ã©ãçã§ãã (å®éã«å€é蟺ã䜿ã£ãŠæããŠã¿ããšè¯ã).ããã, ãã®å®çã¯ãã®èšŒæãã (èŸºæ° Îµ1, ε2 ã®è©äŸ¡ã®ä»æ¹ãå床èŠã), åçŽã°ã©ãã«ã€ããŠã®æ¡ä»¶ãªã®ã§, æ°å D3 ã¯åçŽã°ã©ããäœãããšã¯ã§ããªã.
ãã㯠101ããŒãžç®
103
第6åè¬çŸ©
6.1 æšãšãã®æ°ãäžã
ä»åãšæ¬¡åã® 2åã®è¬çŸ©ã§ã¯ç³»çµ±å³ãååæ§é , ãããã¯ã³ã³ãã¥ãŒã¿ã®ãã¡ã€ã«ã·ã¹ãã ç, å€ãã®çŸè±¡/察象ãè¡šçŸããããšã®ã§ãã, ç°¡åãªæ§é ã§ã¯ãããéèŠãªã°ã©ãã§ãããæšã, åã³, ãã®æ°ãäžãæ³(Cayley (ã±ã€ãªãŒ)ã®å®çãšãã®ç³»ïŒã«ã€ããŠåŠç¿ãã.
6.1.1 æšã®åºæ¬çãªæ§è³ª
ããã§ãããæšããšã¯æ¬¡ã®ããã«ã°ã©ããæãã®ç¹å¥ãªå ŽåãšããŠå®çŸ©ããã.
æ (forest) : éè·¯ãå«ãŸãªãã°ã©ã.æš (tree) : é£çµãªæ.
äŸãã°, å³ 6.114ã«èŒããã°ã©ããæã§ãã, 3ã€ããæåã®ãã¡ã®åã ãæšã§ãã.
å³ 6.114: æã®äŸ. 3 ã€ããæåã®åã ãæšã«çžåœãã.
ãããã®æšã®åºæ¬çãªæ§è³ªã¯æ¬¡ã®å®çã«ãããŸãšããããŠãã. 蚌æã¯æç§æž p.61 ãèªãã§ãããããšã«ããŠ, è¬çŸ©ã§ã¯èª¬æããªã. ååœé¡ãäŸã«æããæšã«åœãŠã¯ããŠç¢ºèªãããã.
å®ç 9.1ç¹ nåãããªãã°ã©ã Tãèãããšã, 次ã®ååœé¡ã¯åå€ã§ãã.
(i) Tã¯æšã§ãã.(ii) Tã«ã¯éè·¯ã¯ç¡ã, 蟺ã nâ 1æ¬ãã.(iii) Tã¯é£çµã§ãã, 蟺ã nâ 1æ¬ãã.(iv) Tã¯é£çµã§ãã, å šãŠã®èŸºã¯ãæ©ãã§ãã.(v) Tã®ä»»æã® 2ç¹ãçµã¶éã¯ã¡ããã© 1æ¬ã§ãã.(vi) Tã«éè·¯ã¯ç¡ãã, æ°ãã蟺ãã©ã®ããã«ä»ãå ããŠãéè·¯ãã§ã, ããã, 1åã®éè·¯ã§ãã.
ããã§, äžã®å®çã®åœé¡ (ii)(iii) ãã, æ Gã®èŸºã®æ°ã«é¢ããŠæ¬¡ã®ç³»ãåŸããã.
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ç³» 9.2æ Gã«ã¯ nåã®ç¹ãš kåã®æåããããšãã. ãã®ãšã, æGã«ã¯ nâ kæ¬ã®èŸºããã.
(蚌æ)éè·¯ãç¡ãé£çµã ãšãããš, nâ 1æ¬ã®èŸºããã. ãããã蟺ã 1æ¬ãã€åæããæäœãé²ãããš
1æ¬èŸºãåæãããš â æåæ° 2, nâ 2æ¬ã®èŸº
2æ¬èŸºãåæãããš â æåæ° 3, nâ 3æ¬ã®èŸº
3æ¬èŸºãåæãããš â æåæ° 4, nâ 4æ¬ã®èŸº
· · · · · · · · ·· · · · · · · · ·
k â 1æ¬èŸºãåæãããš â æåæ° k, nâ kæ¬ã®èŸº
ãšãªã. (蚌æçµãã).
ããã«, å®ç 9.1ã® (ii)ããæšã®ç«¯ç¹æ°ã«é¢ããŠæ¬¡ã®ç³»ãåŸããã.
ç³» 9.3
åç¹ã§ãªãæšã¯, å°ãªããšã 2ç¹ã®ç«¯ç¹ãå«ã.
(蚌æ)æš T : V (T) = {v1, v2, · · · , vp}, p ⥠2, E(T) = {e1, e2, · · · , eq} ãšãããš, å®ç 9.1(ii)ãã
q = pâ 1
ã§ãã, 蟺ã®ç·æ°ã® 2åã¯ã°ã©ãã®æ¬¡æ°ã«çãã (æ¡æè£é¡) :
pâi=1
deg(vi) = 2q
ããçŽã¡ã«
pâi=1
deg(vi) = 2(pâ 1)
ãåŸããã. åŸã£ãŠ, æšã®ç«¯ç¹ã 0, 1 ã ãšãããš, äžåŒå³èŸºãè² ãŸãã¯ãŒããšãªã, ç¹ã®æ°ã 2以äžã®ã°ã©ãã«å¯Ÿãã次æ°ã®å®çŸ©ã«åãã. (蚌æçµãã).
6.1.2 å šåæš
å šåæš (spanning tree) : é£çµã°ã©ã Gã«å¯Ÿã, éè·¯ãç¡ããªããŸã§èŸºãé€å»ããŠæ®ãã°ã©ã (å³ 6.115åç §).
ãããäžè¬åãããš
å šåæ (spanning forest) : nåã®ç¹ãšmæ¬ã®èŸº, kåã®æåããããšããŠ, Gã®åæåã«å¯ŸããŠ, éè·¯ãç¡ããªããŸã§èŸºãé€å»ããæäœãç¹°ãè¿ããŠåŸãããã°ã©ã.
ãã㯠104ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
v w
x y z
e1
e5
e2
e8
e7
e3
e4
e6v
x y z
w
e1
e2
e3e4
å³ 6.115: é£çµã°ã©ãããçæãããå šåæšã®äžäŸ.
éè·¯éæ° (cycle rank) γ(G) : å šåæãåŸããŸã§ã«åæããªããã°ãªããªã蟺ã®æ¬æ°.
γ(G) = (Gã®èŸºæ°)â (nåã®ç¹, kæåãããªãæ G ã®èŸºæ°)
= mâ (nâ k)(ç³» 9.2ãã) = mâ n+ k
ã«ããã»ããéæ° (cutset rank) Ο(G) : å šåæšã®èŸºæ°
Ο(G) = nâ k
åœç¶, γ(G)㚠Ο(G)ã®éã«ã¯ γ(G) + Ο(G) = mã®é¢ä¿ããã.
6.1.3 åºæ¬éè·¯éåãšåºæ¬ã«ããã»ããéå
æš Tã«é¢é£ããåºæ¬éè·¯éå : Tã«å«ãŸããªã Gã®ä»»æã®èŸºãäžã€ Tã«ä»å ãããš, éè·¯ãäžã€ã§ãã.ãã®æäœã«ããã§ããéè·¯ã®éåãåºæ¬éè·¯éåãšåŒã¶ (ãã®äžäŸãšããŠå³ 6.116(å·Š)åç §).
v
x y z
w
e1
e2
e3 e4
v
x y
e1 e2
e5
v
y z
e2
e3
e7
vw
z
e6
e3
e4
v
y z
w
e2
e8
e3
e4
v
x y z
w
e1 e2
e3
e4
x y z
v w
e1
e5
V
V
1
2
{e1,e5}
å³ 6.116: åºæ¬éè·¯éåã®äžäŸ (å·Š) ãšåºæ¬ã«ããã»ããéåã®äžäŸïŒå³).
æš Tã«é¢é£ããåºæ¬ã«ããã»ããéå : Tã®å蟺ãé€å»ããŠåŸãããã«ããã»ããéå (ãã®äžäŸãå³
ãã㯠105ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
6.116(å³)ã«èŒãã).ï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 6.1 ã (2004幎床 æŒç¿åé¡ 6 )
Gãé£çµã°ã©ãã§ãããšã, Gã®äžå¿ (centre)ãšã¯æ¬¡ã®ãããªç¹ vã®ããšã§ãã : vãš Gã®ä»ç¹ã®éã®è·é¢ã®æ倧å€ãã§ããã ãå°ãã. ãã®ãšã, 以äžã®åãã«çãã.
1
2
3
45
6
7
8
9
10
1112
13
14
15 16
17
18
T
(1)端ç¹ãé€å»ããæäœãç¶ããŠè¡ãããšã«ãã, å³ã®æš Tã®äžå¿ãæ±ãã.(2)ã©ããªæšã§ãäžå¿ã¯ 1ã€ã 2ã€ã§ããããšã瀺ã.(3)æšã®äžå¿ã 2ã€ããå Žå, ãããã® 2ç¹ã¯é£æ¥ããŠããããšã瀺ã.(4) 7ç¹ãããªãæšã§, äžå¿ã 1ã€ã®æšãš, 2ã€ã®æšãããããäžã€ãã€äŸç€ºãã.
(解çäŸ)
(1)åé¡æäžã«äžããããæš Tã«å¯Ÿã, ã端ç¹ãé€å»ããæäœã13 ãè¡ããš, 1åç®ã«åé€ããã端ç¹ã°ã«ãŒã㯠{1, 2, 4, 5, 8, 9, 12, 13, 15, 16} ã§ãã, 2åç®ã«åé€ããã端ç¹ã°ã«ãŒã㯠{3, 6, 10, 14, 17}. ãããŠ, æåŸã«åé€ããã端ç¹ã°ã«ãŒã㯠{7, 18}ã§ãã. åŸã£ãŠ, ãããäžé£ã®æäœã«ããæåŸãŸã§çãæ®ãæš Tã®äžå¿ã¯ 11ã§ãã.
(2)ä»®ã«æšã®äžå¿ã 3ã€ãããšãã. ãã®ãšã, å®ç 9.1 (iv)ãã, æšã®å šãŠã®èŸºã¯æ©ã«ãªã£ãŠããããšãã, 端ç¹ãé€å»ããŠããæäœã«ãã, æ®ãæšãšããŠã¯å³ 6.117ã®å Žåãããªã. ãã®å Žåã«å¯ŸããŠ, ã
2
v
1
å³ 6.117: 端ç¹ãåé€ããããšã«ãã£ãŠã§ããã°ã©ãã®äžäŸ.
ãã«æ¬¡ã® 2éãã®å¯èœæ§ãããåŸã.
(I) ç¹ 1ãšç¹ 2ã«çµåããŠããæåã®å€§ãããçããå Žå
13 ããã§èšãã端ç¹ãé€å»ããæäœããšã¯ããå°ãæ£ç¢ºã«èšããš, ãã®è§£çã«ç€ºããããã«ã端ç¹ã®ã°ã«ãŒããé€å»ããæäœãã®ããšã§ã.
ãã㯠106ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
(II) ç¹ 1ãšç¹ 2ã«çµåããŠããæåã®å€§ãããç°ãªãå Žå
(I)ã®å Žåã«ã€ããŠèãããš, ç¹ 1ãšç¹ 2ãš vã«æ¥ç¶ãã 2ã€ã®èŸºãé€å»ããããšã«ãã, å¯äžã®äžå¿vãåŸããã.(II)ã®å Žåã«é¢ããŠ, ç¹ 2ã«çµåããŠããæåã®æ¹ã倧ãããšãããš, ç¹ 1ãšç¹ vãçµã¶èŸºãé€å»ãã
ããšã«ãã, (v, 2)ãšãã 2ã€ã®äžå¿ãåŸããã.åŸã£ãŠ, (I)(II)ã®ãããã®å Žåã«ããŠã, æšã®äžå¿ã 3ã€ãããšããå¯èœæ§ã¯ããåŸã, å¿ ã, åŒãç¶ãé€å»ã®ããã»ã¹ã«ãã, 1ã€ãŸã㯠2ã€ã®äžå¿ã«è¡ãçãããšã«ãªã.
(3)ãããä»®ã«, æšã®äžå¿ã 2ã€ãã, ããããé£æ¥ããŠããªããšãããš, ãã®å Žåã«ã¯å®ç 9.1 (iv)ã«ãã, æšã®å šãŠã®èŸºã¯æ©ã§ãã, äžå¿ã§ããç¹ 1,2ã¯æ¬¡æ°ã 2ã®ç¹ vãä»ããŠçµåããŠããã¯ãã§ãã (å³6.118åç §). åŸã£ãŠ, ç¹ 1,2ãšãã® vãšã®æ¥ç¶èŸºãé€å»ãããšäžå¿ã 1ã€ãšãªã£ãŠããŸã, äžå¿ã 2ã€
1 v 2
å³ 6.118: æšã§ã¯å šãŠã®èŸºãæ©ã§ãã.
ãããšããä»®å®ã«åãã. ãã£ãŠ, æšã®äžå¿ã 2ã€ããå Žåã«ã¯, ãããã¯å¿ ãé£æ¥ããŠãããšçµè«ä»ãããã.
(4)ç¹ã 7ã€ã§, äžå¿ãïŒã€ãŸã㯠2ã€ã®ã°ã©ãã®äžäŸãããããå³ 6.119ã«èŒãã.
1
2
3
4
5
6
7
1
2
3 4
6
5
7
å³ 6.119: 7 ç¹ãããªãæšã§äžå¿ã 1 ã€ã®ãã® (å·Š) ãšäžå¿ã 2 ã€ã®ãã®ã®äžäŸ.
ᅵ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 6.2 ã (2005幎床 æŒç¿åé¡ 6 )
(1)å³ã«ç€ºããã°ã©ãã®å šåæšãå šãŠæã.
a b
cd
e
(2)ã°ã©ã Gã®èŸºã®ããéåã Câ ãšãã. ã©ã®å šåæã«ã Câ ãšå ±éãªèŸºããããªãã°, Câ ã«ã¯ã«ããã»ãããå«ãŸããããšãäŸãæããŠç€ºã.
(解çäŸ)
(1)å³ 6.120ã®ããã«åé¡ã®ã°ã©ãã®å蟺ã«çªå·ããµããš, 蟺éå I : {1, 2, 3}, 蟺éå II : {4, 5, 6}ã®ãã
ãã㯠107ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãããã, èŠçŽ ã 1ã€ãã€åãåºã, ãã®èŸºãåé€ããã°å šåæšãåŸããã. åŸã£ãŠ, èãããå šåæš
a
d
e
b
c
1
2
3 4
5
6
å³ 6.120: åé¡ã®ã°ã©ãã®å蟺ã«çªå·ããµã.
ã®æ°ã¯ 3à 3 = 9éãã§ãã. ããããã®å šåæšãšåé€ãã蟺ã®çµã¿åãã㯠A : (1,4), B : (1,5), C :(1,6), D : (2,4), E : (2,5), F : (2,6), G : (3,4), H : (3,5), I : (3,6) ã§ãã, ãããããæããšå³ 6.121ã®ããã«ãªã.
A B
C D
E F
G H
I
å³ 6.121: å¯èœãªå šåæš.
(2)äŸãšããŠå³ 6.122(å·Š)ã®ãããªã°ã©ããèãã. ãã®ãšã, 蟺 eã¯ã«ããã»ããã«ãªã£ãŠãã (ãã®å Žå
e
a
b
c
e
e
e
å³ 6.122: ããã§èããé£çµã°ã©ã G(å·Š) ãšãã®å šåæš (å³).
ã¯ãæ©ããšãèšãã), ãã®èŸºãåé€ãããš, é£çµã°ã©ãã¯ç¹ãšäžè§åœ¢ã«åé¢ãã. ããã§, ãã®ã°ã©ãã®å šåæšãäœãããã«ã¯, äžè§åœ¢ã®å蟺ã 1蟺ã ãåé€ããã°ããã®ã§, å¯èœãªå šåæšã¯å³ 6.122(å³)ã®ããã«ãªã, 蟺 eã¯å šãŠã®å šåæšã«å ±éã«å«ãŸããããšã«ãªã. åŸã£ãŠ, ãã®ã°ã©ãã«é¢ããŠã¯é¡æãæºããããŠããããšã«ãªã.
ãã㯠108ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäžï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 6.3 ã (2006幎床 æŒç¿åé¡ 6 )
T1, T2ã¯é£çµã°ã©ã Gã®å šåæšã§ãããšãã. ãã®ãšã, 以äžã®åãã«çãã.
(1) eã T1ã®ä»»æã®èŸºã§ãããšã, T1ã®èŸº eã蟺 f ã§çœ®ãæããã°ã©ã (T1 â {e}) ⪠{f}ãå šåæšã«ãªããããª, T2ã®èŸº f ãååšããããšãäŸãæããŠç€ºã.
(2) (1)ã§ã®æäœãç¹°ãè¿ãããšã«ãã, T1 㯠T2 ã«ãå€æãã§ããããšãäŸãæããŠç€ºã. ãã ã, T1ã®èŸºã®äžã€ã T2ã®èŸºã§çœ®ãæããå段éã«ãããŠ, å šåæšã«ãªã£ãŠãããã®ãšãã.
(解çäŸ)
(1)å³ 6.123ã«èŒããã°ã©ã Gãšãã® 2ã€ã®å šåæš T1, T2 ãèããã. ããã§, åé¡æã«äžããããŠãã
G
1
23
4 5
12
3
4
2
5
T1
T2
å³ 6.123: ããã§èããã°ã©ã G ãšãã®å šåæš T1, T2.
å šåæš T1 ã®èŸº eã 3ã«, å šåæš T2 ã®èŸº f ã 5 ãšãããš (ä»åŸãã®ãããªå¯Ÿå¿ã¥ãã e = 3, f = 5ãšæžãããšã«ãã), å šåæš T1 ãã eãåé€ã, 代ããã«å šåæš T2ã®èŸº f ãå ãããã® : (â»ä»¥äžã§ã¯äžé£ã®ãã®äœæ¥ããæäœããšåŒã¶)ã¯ã°ã©ã Gã®å šåæšãšãªã£ãŠãã. åŸã£ãŠ
T1 â {e} ⪠{f} ã°ã©ã Gã®å šåæš
ãæç«ããŠããããšãããã (ãã®æäœã§åŸãããå ·äœçãªå šåæšã¯å³ 6.124ã® t1). å šåæšã®å®çŸ©ãã, T1, T2 ãšãã«èŸº g ãäžã€å ããããšã«éè·¯ãã§ããã (ãã®ããã«ã§ããã°ã©ã Gã®èŸº 2, 3, 5ãããªãéè·¯ã䟿å®äž C = 235ãšåŒã¶ããšã«ãã. ãŸã, 蟺 gã¯ãã®å šåæšãäœãéã«åé€ããã蟺ã§
ããããšã«æ³šæ), T1 ã«ãããŠåé€ããã蟺 f = 3ãå±ãããã®éè·¯ C = 235ã«ã¯èŸº f ãšã¯ç°ãªã蟺
2, 5(= g)ããããã, å šåæš T2 ã«ãããŠãã® g = 5 ãååšããã° f ãåé€ãããæšã« T2 ãããã®
g = 5ã eãšããŠä»ãå ããããšã«ãã£ãŠåã³ã°ã©ã Gã®å šåæšãã§ãã. å šåæšã®äœãæ¹ããæããã«, ã©ã®ããã« T2ãéžãŒãã, ãã®æšã«ã¯ 2, 3, 5ã®ãã¡ã®ãããã 2ã€ã®èŸºãååšããããã ãã,åžžã«ãã®ãããªèŸº eãéžã¶ããšãã§ãã. ããã¯ããã§èª¿ã¹ãã°ã©ãGã«éãã, ä»»æã®ã°ã©ã Gã
ãã³ãã®å šåæšã«å¯ŸããŠæç«ããã®ã¯æãã.(2)å³ 6.123 ã«äžããããã°ã©ãã®å šåæš T1, T2ã«å¯ŸããŠåé¡ã«äžããããæäœã蟺 e = 3, f = 2 ã«ã€ããŠè¡ã£ãå šåæšã t1 = T1 â {e} ⪠{f} ãšã, ãã®æš t2ã«å¯ŸããŠæäœã蟺 e = 3, f = 5ã«ã€ããŠè¡ã£ãæšãèãããš
t2 = t1 â {e} ⪠{f} T2
ãšãªã, T2ãåŸããã. ãããã® 2åã®æäœéçšãå³ç€ºãããšå³ 6.124ã®ããã«ãªã. ãŸã, æããã«ãã®ç§»è¡ : T1 â T2ã®éçšã§åŸãããæš t1ã¯ã°ã©ã Gã®å šåæšã§ãã.
ãã㯠109ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
1 2
5 4
2
5
t1 t2
å³ 6.124: å šåæš T1 ãã e = 3, f = 5 ã®æäœã§ã§ããæš t1 ãš t1 ãã e = 1, f = 4 ã®æäœã«ãã£ãŠã§ãã t2. æããã« t2 ã¯T2 ãšå圢ã§ãã. ãŸã, t1, t2 ãšãã«ã°ã©ã G ã®å šåæšã§ãã.
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ãäŸé¡ 6.4 ã (2005幎床æ å ±å·¥åŠæŒç¿ II(B) #1)
次ã®åã°ã©ãã®éè·¯éæ° Î³(G), ã«ããã»ããéæ° ÎŸ(G)ãæ±ãã.(1) K5 (2) K3,3 (3) W5 (4) N5 (5) ããŒã¿ãŒã¹ã³ã»ã°ã©ã
(解çäŸ)çãã®ã¿æžã. (1) γ(K5) = 6, Ο(K5) = 4 (2) γ(K3,3) = 5, Ο(K3,3) = 4 (3) γ(W5) = 5, Ο(W5) = 5, (4)γ(N5) = 0, Ο(N5) = 0 (5) γ(ããŒã¿ãŒã¹ã³) = 6, Ο(ããŒã¿ãŒã¹ã³) = 9.
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ãäŸé¡ 6.5 ã (2007幎床 æŒç¿åé¡ 6 )
(1)ããŒã¿ãŒã¹ã³ã»ã°ã©ãã®å šåæšãäžã€æã.(2)ã°ã©ã G㯠εã®èŸºæ°ãš |G|åã®ç¹ãå«ããšãã. ãã®ãšã, Gã®ä»»æã®å šåæšã«å¯Ÿã, εâ |G|+ 1åã®åºæ¬éè·¯ãååšããããšã (1)ã® G â¡ ããŒã¿ãŒã¹ã³ã»ã°ã©ãã«é¢ããŠç€ºã, 次ãã§, ä»»æã®ã°ã©ã Gã«å¯ŸããŠç€ºã.
(解çäŸ)
(1)ããŒã¿ãŒã¹ã³ã»ã°ã©ãã¯å³ã®å®ç·+ç Žç·ãããªãã°ã©ãã§ç¹æ° |G| = 10, èŸºæ° Îµ = 15ãããªã. ããããå³ã®ç Žç·: 23, 68, 710, 49, 810, 27 ã® 6æ¬ã®èŸºãé€å»ãããšå³ã®å®ç·ã®ãããªå šåæšãäžã€ã§ãã.
1
2
34
5
6
7
8
9
10
å³ 6.125: ããŒã¿ãŒã¹ã³ã»ã°ã©ãã®å šåæš (å®ç·).
ãã㯠110ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
(2) (1)ã§åŸãããããŒã¿ãŒã¹ã³ã»ã°ã©ãã®å šåæšã«ãããŠ, é€å»ãã蟺 23ãå ãããšéè·¯ 123451 ãåŸã
ã, 68ãå ãããšéè·¯ 1683451ãåŸãã, 蟺 710ãå ãããšéè·¯ 71051697ãåŸãã, 蟺 49 ãå ãã
ãšéè·¯ 945169ãåŸãã, 蟺 810 ãå ãããšéè·¯ 8345108ãåŸãã, 蟺 27ãå ãããšéè·¯ 279612 ãåŸ
ããã. åŸã£ãŠ, (1)ã§é€å»ãã蟺ãäžã€å ããããšã«éè·¯ãäžã€ãã€åŸãã, ãããåºæ¬éè·¯ãšãªã.ãã£ãŠ, åºæ¬éè·¯ã®åæ°ã¯å šåæšãã§ãããŸã§é€å»ãã蟺ã®æ¬æ°ã«çãã. äŸãã°, (1)ã®ããŒã¿ãŒã¹ã³ã»ã°ã©ãã®å Žåã«ã¯, 6æ¬ã§ãã, ããã¯ç¢ºã㫠εâ |G|+ 1 = 15â 10 + 1 = 6ãšçãã.ç¹æ° |G|, èŸºæ° Îµãæã€äžè¬ã®ã°ã©ãã«ãããŠã¯, ã§ããããå šåæšã®èŸºæ°ãã|G|åã®ç¹ãããªãæšã®èŸºæ°ã¯ |G| â 1æ¬ã§ãããããšãæãåºãã°, ãã¯ã, |G| â 1æ¬ã§ãããã, å šåæšãã§ãããŸã§ã«é€å»ããªããã°ãªããªã蟺æ°ã¯ εâ (|G| â 1) = εâ |G|+ 1æ¬ã§ãã, ãã®èŸºãäžã€ãã€å ãããšåºæ¬éè·¯ãäžã€ãã€ã§ããã®ã§, çµå±, åºæ¬éè·¯ã®åæ°ã¯ εâ |G|+ 1ãšãªã.
ãã㯠111ããŒãžç®
113
第7åè¬çŸ©
6.1.4 æšã®æ°ãäžã
ç¹ã«ã©ãã«ãä»ããæšããã©ãã«ä»ãæšããšèšãã, ãã®ããã«åç¹ã«ã©ãã«ãä»ããŠæšãåºå¥ããå Žå, ãã®ç·æ°ã¯ããã€ããã, ãšããããšãåé¡ã«ãªã. ãã®çãã¯Cayley (ã±ã€ãªãŒ)ã®å®çãšããŠãŸãš
ããããŠãã, ãnåã®ç¹ãããªãã©ãã«ä»ãæšã®ç·æ°ã¯ nnâ2 åã§ããããšããããã«, ãšãŠãç°¡åãªåœ¢ã§è¡šããã. ããã§ã¯ãã®å®ç (å ¬åŒ)ã®èšŒæã詳ããè¿œã, é¢é£ããç³», åã³, ããã€ãã®äŸé¡ããšããã,ãã®ç解ãæ·±ããŠè¡ãããšã«ããã.
å®ç 10.1 (Cayley ã®å®ç)ãã nç¹ã®ç°ãªãã©ãã«ä»ã®æšã¯ nnâ2 åãã.
(蚌æ)ãŸãã¯æºåãšããŠ
⢠deg(v) = k â 1ã®ç¹ vãå«ãã©ãã«ä»ãã®æšã A
⢠deg(v) = kã®ç¹ vãå«ãã©ãã«ä»ãã®ã®æšã B
ãšå®çŸ©ããŠãã.ããã§è¿°ã¹ã蚌æã®ãã€ã³ãã¯ããã©ãã«ä»ãæš Aããã©ãã«ä»ãæš Bãäœãé£é (linkage) ã®ç·æ°ã
ãšãéã«ã©ãã«ä»ãæš Bããã©ãã«ä»ãæš Aãäœãé£éã®ç·æ°ããçããããšããæ¡ä»¶ (é¢ä¿åŒ)ããå¯èœãªã©ãã«ä»ãæšã®ç·æ°ãæ±ãã, ãšããç¹ã§ãã.
ããã§ã¯ä»¥äžã§é£é : Aâ B, åã³, é£é : Bâ AãªãæäœãããããèŠãŠè¡ãããšã«ããã. ãã®é, nåã®ç¹ãããªãã©ãã«ä»ãæšã®ããç¹ vã®æ¬¡æ°ã kã§ãããã®ã®ç·æ°ã T (n, k)ã§è¡šããŠããããšã«ãã.
é£é : Aâ Bå³ 6.126ã®ããã« Aãç¹ v ã«æ¥ç¶ããŠããªã蟺ã§åé¢ã (å³ 6.126ã® (a) â (b)), ç¹ vãšç¹ z ãšãçµã¶ãš
(å³ 6.126ã® (b) â (c)), deg(v) = kã§ããã©ãã«ä»ãæš BãåŸããã. ããŠ, ã©ãã«ä»ãæš Aã®éžã³æ¹ã¯
cut
v
z
v
z
vz
(a) (b)
(c)
å³ 6.126: é£é : A â B.
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
T (n, k â 1)éããã, 1ã€ã® Aã«å¯ŸããŠ, åæãã蟺ã®éžã³æ¹ã¯
(ç¹ vã«æ¥ç¶ããŠããªã蟺ã®éžã³æ¹) = (æš Aã®èŸºã®æ¬æ°)â (ç¹ vã®æ¬¡æ°)
= (nâ 1)â (k â 1) = nâ k (éã)
ã ããããã, é£é : Aâ Bã®ç·æ°ã¯
(é£é : Aâ B ã®ç·æ°) = T (n, k â 1)(nâ k)
ãšãªã. 次ã«é£é : Bâ A ãèãã.
é£é : Bâ Aå³ 6.127ã®ããã«, ã©ãã«ä»ãæš Bããç¹ v, åã³, ãã®æ¥ç¶èŸºãé€å»ããŠåŸããã, æš Bã®æåã§ããäžé£ã®éšåæšã (T1,T2, · · · ,Tk) ãšãã (å³ 6.127ã® (a)). ããã§åéšåæšã«å«ãŸããç¹ã®ç·æ°ã¯ ni ã§ãã,åœç¶ã®ããšãªãã
nâ 1 (v以å€ã®ç¹ã®æ°) =kâ
i=1
ni
ãæºãããŠãã. ãã®ãšã, ã©ãã«ä»ãæš Bããç¹ v, åã³, ãã®æ¥ç¶èŸºã® 1æ¬ãé€å»ã (ãã®éã«ã§ããæ
v
w1,T1
w2,T2
w3,T3
cut
w2,T2
w3,T3
w1,T1
v
v
w2,T2
w3,T3
w1,T1
(a) (b)
(c)
å³ 6.127: é£é : B â A.
åã§ããéšåæšã Ti ãšåä»ãã)(å³ 6.127ã® (a) â (b)), Ti 以å€ã®éšåæš Tj ã®ä»»æã®ç¹ uãšéšåæš Ti
å ã®ä»»æã®ç¹ wi ã蟺ã§çµã¶ (å³ 6.127ã® (b) â (c))ãš deg(v) = k â 1ã®ã©ãã«ä»ãæš AãåŸããã.
ããã§ã©ãã«ä»ãæš Bã®éžã³æ¹ã¯ T (n, k)éãã§ãã, ç¹ wi ãš Ti 以å€ã®éšåæš Tj ã®ä»»æã®ç¹ãçµã¶æ¹
æ³ã¯
(ç¹ vãé€ãç¹ã®ç·æ°)â (éšåæš Ti ã«å±ããç¹ã®ç·æ°) = (nâ 1)â ni (éã)
ã ããããã, é£é : Bâ Aã®ç·æ°ã¯
T (n, k)kâ
i=1
(nâ 1â ni) = T (n, k){(nâ 1â n1) + (nâ 1â n2) + · · ·+ (nâ 1â nk)}
= T (n, k){(nâ 1)k â (n1 + n2 + · · ·+ nk)} = T (n, k)(nâ 1)(k â 1)
ãã㯠114ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãšãªã.é£é : Aâ B,Bâ Aã®ç·æ°ãçãããšçœ®ãããšã«ãã, é¢ä¿åŒ :
(nâ k)T (n, k â 1) = (nâ 1)(k â 1)T (n, k)
ãåŸããã.ãšããã§, T (n, nâ 1) = 1ã«æ³šæããŠ, äžé¢ä¿åŒã§ k = nâ 1, nâ 2, nâ 3, · · ·ãšæžãåºããŠè¡ã£ãŠã¿ããš
k = nâ 1ã®ãšã
T (n, nâ 2) = (nâ 1)(nâ 2)T (n, nâ 1) = (nâ 1)(nâ 2)
k = nâ 2ã®ãšã
2T (n, nâ 3) = (nâ 1)(nâ 3)T (n, nâ 2) = (nâ 1)2(nâ 2)(nâ 3)
ã€ãŸã
T (n, nâ 3) =12(nâ 1)2(nâ 2)(nâ 3)
k = nâ 3ã®ãšã
3T (n, nâ 4) = (nâ 1)(nâ 4)T (n, nâ 3) =12(nâ 1)3(nâ 2)(nâ 3)(nâ 4)
ã€ãŸã
T (n, nâ 4) =1
3 · 2 · 1(nâ 1)3(nâ 2)(nâ 3)(nâ 4)
ãåŸããã. ãããäžè¬åãããš, äºé å®çãã k = k + 1ã®ãšã
T (n, k) =(nâ 1)nâk+1(nâ 2)
(k â 1)(k â 2) · · · = nâ2Ckâ1(nâ 1)nâkâ1
ãšããçµæãåŸããã. åŸã£ãŠ, æ±ããã©ãã«ä»ãæšã®ç·æ° T (n) ã¯äžèšã® T (n, k)ã«é¢ã, k = 1 ããk = nâ 1ãŸã§åããšãããšã«ãã
T (n) =nâ1âk=1
T (n, k)
=nâ1âk=1
nâ2Ckâ1(nâ 1)nâkâ1
=nâ1âk=1
nâ2Ckâ11kâ1(nâ 1)(nâ2)â(kâ1) = {(nâ 1) + 1}nâ2 = nnâ2
ãšãªã, Cayleyã®å®çã蚌æããã. (蚌æçµãã).
ãã®å®çã«é¢ããäŸé¡ãäžã€èŠãŠãã.
ãã㯠115ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäžï¿œ
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ãäŸé¡ 7.1ã (2003幎床 ã¬ããŒãèª²é¡ #5 åé¡ 1 )
nç¹ã®ã©ãã«ä»ãæšã®åæ°ã T (n)ãšãã. ãã®ãšã以äžã®åãã«çãã.
(1) kç¹ã®ã©ãã«ä»ãæšãš nâ kç¹ã®ã©ãã«ä»ãæšã®çµã³æ¹ã®ç·æ°ãèšç®ããããšã§æ¬¡ã®é¢ä¿åŒã瀺ã.
2(n â 1)T (n) =nâ1âk=1
nCk k(nâ k)T (k)T (nâ k)
(2)次ã®é¢ä¿åŒã瀺ã.
nâ1âk=1
nCk kkâ1(nâ k)nâkâ1 = 2(nâ 1)nnâ2
(解çäŸ)
(1) nç¹ãããªãæšã®èŸºãäžèŸºã ãåã£ãŠ, 2ã€ã®ã°ã©ã A,B ãäœãæ¹æ³ã¯
2Ã (nâ 1)Ã T (n) = 2(nâ 1)T (n) (6.140)
éãååšãã. ããã§, T (n)㯠nç¹ãããªãæšã®ç·æ°ã§ãã, ä¿æ° (nâ 1)ã¯ã©ã®èŸºãåãããšããèªç±åºŠã, ãŸã, ä¿æ° 2ã¯ã°ã©ã A,Bã®äº€æã«ããèªç±åºŠãè¡šããŠãã.
ãšããã§, k ç¹ã®ã©ãã«ä»ãæš A ãš (n â k) ç¹ã®ã©ãã«ä»ãæš B ã®çµã³æ¹ã®ç·æ°ã¯, k ç¹ã®ã©ãã«ä»ãæšã®äžããäžç¹ãéžã¶æ¹æ³ã® kT (k) éããš n â k ç¹ã®ã©ãã«ä»ãæšã®äžããäžç¹ãéžã¶æ¹æ³ã®(nâ k)T (nâ k) éããæãåãã, ããã« nåã®ç¹ãã k (k = 1, 2, · · · , nâ 1) åã®ç¹ãéžã㧠A,Bãäœãå Žåã®æ°ãæãåãããã ãã®åæ°ã ãååšãããã
nâ1âk=1
nCk kT (k)(nâ k)T (nâ k) =nâ1âk=1
nCk k(nâ k)T (k)T (nâ k) (6.141)
ãšãªã. (6.140)(6.141) ã¯çããã®ã§
2(nâ 1)T (n) =nâ1âk=1
nCk k(nâ k)T (k)T (nâ k) (6.142)
ãåŸããã.
(2) (6.142)åŒã«ãããŠ, Cayley ã®å®ç : T (n) = nnâ2 çãçšãããš
2(nâ 1)nnâ2 =nâ1âk=1
nCk k(nâ k)kkâ2(nâ k)nâkâ2 =nâ1âk=1
nCk kkâ1(nâ k)nâkâ1 (6.143)
ãåŸããã.
ãã®ç¯ã®æåŸã« Cayleyã®å®çããå°ãããç³»ãäžã€ãããŠããã.
ç³» 10.2ããå®å šã°ã©ãKn ã®å šåæšã®ç·æ°ã¯ nnâ2 åã§ãã.
ãã㯠116ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
(蚌æ)
å®å šã°ã©ãKnãã, åç¹ã«æ¥ç¶ããŠãã蟺ãé©åã«é€å»ããããšã«ãã, nç¹ã®ã©ãã«ä»ãæš (å šåæš)ãåŸãã, éã«, nç¹ã®ã©ãã«ä»ãæšã®åç¹ã«, åç¹ã®æ¬¡æ°ã nâ 1ã«ãªããã, é©åã«èŸºãå ããããšã«ããå®å šã°ã©ãKnãåŸããã (äŸãã°, å³ 6.128ã«K5ã®å ŽåãèŒãã). åŸã£ãŠ, nç¹ã®ã©ãã«ä»ãæšã¯å®å šã°ã©ãKnã®å šåæšã«äžæã«å¯Ÿå¿ã, ãã£ãŠ, å®å šã°ã©ãKnã®å šåæšã®ç·æ°ã¯ nnâ2ã§ãã. (蚌æçµãã).
K 5
å³ 6.128: å®å šã°ã©ã K5 ãšãã®å šåæš.
6.1.5 ç¹è¡åãšè¡åæšå®ç
ããã§åŠã¶ è¡åæšå®ç (matrix-tree theorem) ã¯, äžããããã°ã©ã Gã®ã©ãã«ä»ãå šåæšã®åæ°ãäžããå®çšçãªå®çã§ãã.å ·äœçã«å®çãšãã®å¿çšäŸãèŠãåã«, ã°ã©ãGã®ç¹è¡å (vertex matrix) D ã次ã®ããã«å®çŸ©ãã
14 .
ã°ã©ã Gã®ç¹è¡åDãšã¯, ãã®èŠçŽ Dij ã
Dij =
{ç¹ vi ã®æ¬¡æ° (i = j ã®ãšã)
â(ç¹ vi ãšç¹ vj ãçµã¶èŸºã®æ¬æ°) (i ï¿œ= j ã®ãšã)
ã§äžããããè¡åã§ãã.
ãã®ãšã, ã°ã©ã Gã®å šåæšã®æ¬æ° Ï(G)ã¯è¡åDã®ä»»æã®äœå åã§äžãããã. ã€ãŸã, è¡åDã®ç¬¬
iè¡, 第 j åãåé€ããŠåŸãããè¡åãD(i, j) ãšãããš
Ï(G) = (â1)i+j |D(i, j)|
ãå šåæšã®æ¬æ°ãäžãã. ããã§, |X|ã¯è¡åX ã®è¡ååŒãæå³ãã.ãªã, å®çšçã«ã¯è¡åDã®ãµã€ãºãN ÃN ãªãã°, i = j = N ãšéžã¶ã®ãæ±ãããã, ãã®ãšã
Ï(G) = |D(N,N)|
ãå šåæšã®ç·æ°ãšãªã. 以äžã®å 容ãè¡åæšå®çãšåŒã¶.
ãã®å®çã®äœ¿ãæ¹ãå ·äœçã«èŠãããã«, 次ã®ãããªäŸé¡ãèããŠã¿ãã.
14 ãã®è¬çŸ©ã§ã¯åã ã®ã°ã©ãã®ããŒã¿æ§é ãè¡šçŸããããã®è¡åãæ¢ã«ããã€ãåããããŠããã, ãã®ç¹è¡å㯠5 çªç®ã®è¡åã§ãã. åèª, ãããŸã§ã«åŠãã ãé£æ¥è¡åããæ¥ç¶è¡åããã¿ã€ã»ããè¡åããã«ããã»ããè¡åãã埩ç¿ããŠããããš.
ãã㯠117ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäžï¿œ
ᅵ
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ãäŸé¡ 7.2
é£æ¥è¡åAã
A =
âââ
0 1 11 0 11 1 0
âââ
ã§äžããããã°ã©ã Gã®å šåæšã®ç·æ° Ï(G)ãæ±ãã. ãŸã, ãã®å šåæšãå šãŠå³ç€ºãã.
(解çäŸ)
é£æ¥è¡åAãæã€ã°ã©ã Gãå³ç€ºããŠã¿ããšå³ 6.129(å·Š)ãšãªã. ãã®ã°ã©ã Gã®ç¹è¡åDã¯, ãã®å®
1 2
3
1 2
3
1 2
3
1 2
3
å³ 6.129: é£æ¥è¡å ã§äžããããã°ã©ã G(å·Š) ãšãã® 3 ã€ã®å šåæš (å³).
矩ãã
D =
âââ
2 â1 â1â1 2 â1â1 â1 2
âââ
ã§ãã, ãã® i = j = 3ã§ã®äœå åã, ãã®ã°ã©ã Gã®å šåæšã®ç·æ° Ï(G)ãäžã
Ï(G) =â£â£â£â£ 2 â1â1 2
â£â£â£â£ = 4â 1 = 3 (å)
ãšãªã. ãã® 3ã€ã®å šåæšãæããšå³ 6.129(å³)ã®ããã«ãªã.
ãã㯠118ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäžï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 7.3 ã (2004幎床 æŒç¿åé¡ 7 )
1. ä»åã®è¬çŸ©ã§åŠãã Cayleyã®å®çã®èšŒæãåèã«ããŠ, äžèšã®åãã«çãã.(1) nåã®ç¹ãããªãæšã§, äžããããç¹ vã端ç¹ã«ãªã£ãŠãããã®ã¯äœåããã ?(2) nåã®ç¹ãããªãæšã®äžããããç¹ vã端ç¹ãšãªã£ãŠãã確ç P (n)ãæ±ãã.ãŸã, ç¹ã®æ° nãç¡é倧ã®ãšãã® P (n)ã®æ¥µéå€ã
limnââP (n) =
1e
ã§äžããããããšã瀺ã. ãã ã, eã¯èªç¶å¯Ÿæ°ã®åºã§ãã.
2. é£æ¥è¡åAã
A =
ââââââ
0 1 1 01 0 0 11 0 0 20 1 2 0
ââââââ
ã§äžããããã°ã©ã Gã«é¢ããè¡åæšå®çã«ã€ããŠä»¥äžã®åãã«çãã.(1)ã°ã©ã Gã®ç¹è¡åDãæ±ãã.(2)è¡åæšå®çã«ãã, ã°ã©ã Gã®å šåæšã®ç·æ° Ï(G)ãæ±ãã.(3) (2)ã§åŸãããåæ°ã ãååšããå šåæšãå ·äœçã«å šãŠå³ç€ºãã.
(解çäŸ)
1.(1)ä»åã®è¬çŸ©ã§åŠç¿ãã Cayleyã®å®çã®èšŒæã®éçšã§åŸãããé¢ä¿åŒ :
T (n, k) = nâ2Ckâ1 (nâ 1)nâkâ1 (6.144)
ã«æ³šç®ãã. ããã¯, nç¹ãããªãæšã«ããã, ããç¹ v ã®æ¬¡æ°ã kã§ãããã®ã®åæ°ãäžãããã
ã§ãããã, åé¡ãšãªã£ãŠãããäžããããç¹ vã端ç¹ã§ããæšã®åæ°ãã¯äžé¢ä¿åŒã§ k = 1ãšçœ®ãããã®ã«çãã. åŸã£ãŠ, æ±ããæšã®åæ°ã¯
T (n, 1) = nâ2C0 (nâ 1)nâ2 = (nâ 1)nâ2 (6.145)
ã§ãã.(2)æ±ãã確ç P (n)㯠nåã®ç¹ãããªãã©ãã«ä»ãæšã®åæ° nnâ2ã§äžã®çµæã§ãã T (n, 1)ãå²ã£ããã®ã«çžåœããã®ã§
P (n) =T (n, 1)nnâ2
=(
1â 1n
)nâ2
(6.146)
ãæ±ããçãã§ãã.(3)èªç¶å¯Ÿæ° eã®å®çŸ©ãã
limnââP (n) = lim
nââ
(1â 1
n
)nâ2
= limnââ
(1â 1
n
)n
=1e
(6.147)
ãšãªã, é¡æã瀺ããã.
ãã㯠119ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
(åè)P (n)ã®æ¥µéå€ :
limnââ
(1â 1
n
)n
=1e
(6.148)
ã®ç€ºãæ¹ãšããŠ, äŸãã° P (n)ã®å¯Ÿæ°ããšã£ããã®ã®æ¥µéå€ :
limnââ log
(1â 1
n
)n
= limnâân log
(1â 1
n
)(6.149)
ãèããããšã«ãã£ãŠãéæ¥çãã« (6.148)ã瀺ãããšãã§ããŸã. (6.149)ã®æ¥µéå€ã¯ãã®ãŸãŸã§ã¯
limnâân =â, lim
nââ log(
1â 1n
)= 0 (6.150)
ãªã®ã§, âà 0ãè©äŸ¡ããããšã«ãªã£ãŠåä»ã ã, log(1 â 1/n)ã (1/n)ã§å±éããã°
log(
1â 1n
)= â 1
nâ 1
2n2+O
(1n3
)(6.151)
ãšãªãã®ã§,
n log(
1â 1n
)= â1â 1
2n+O
(1n2
)(6.152)
ã§ãã, 極éå€ (6.149)ã¯ç°¡åã«
limnââ log
(1â 1
n
)n
= â1 (6.153)
ã®ããã«æ±ããããšãã§ãã. åŸã£ãŠ, nâ âã®ãšãã«äžåŒã® logã®äžèº«ã 1/eã«è¿ã¥ãã¹ãããšã¯æããã§ãã, ããã§æ¥µéå€ (6.148)ã瀺ããããšã«ãªã.
2.(1)é£æ¥è¡åAã«ããäžããããã°ã©ã Gã¯å³ 6.130ã®ããã«ãªã. åŸã£ãŠ, æ±ããç¹è¡åDã¯
1 3
24
G
å³ 6.130: é£æ¥è¡å A ã«ãã£ãŠå®çŸ©ãããã°ã©ã G.
D =
ââââââ
2 â1 â1 0â1 2 0 â1â1 0 3 â20 â1 â2 3
ââââââ (6.154)
ã§ãã.
ãã㯠120ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
(2) i = j = 4ã§äœå åå±éããããšã«ãã, ã°ã©ã Gã®å šåæšã®åæ° Ï(G)ã¯
Ï(G) = (â1)4+4
â£â£â£â£â£â£â£2 â1 â1â1 2 0â1 0 3
â£â£â£â£â£â£â£ = (â1)
â£â£â£â£â£ â1 â12 0
â£â£â£â£â£ + 3â£â£â£â£ 2 â1â1 2
â£â£â£â£ = â2 + 3 · 3 = 7 (å)
(6.155)
ãšãªã.(3)ã°ã©ã Gã® 7éãã®å šåæšãå³ç€ºãããšå³ 6.131ã«ãªã.
1 3
2 4
1 3
2 4
1 3
2 4
1 3
2 4
å³ 6.131: é£æ¥è¡å A ã«ãã£ãŠå®çŸ©ãããã°ã©ã G ã®å šåæš. ãã ã, 蟺 3 â 4 ãåé€ããã, 蟺 4 â 3 ãåé€ãããã«ãã,ããã 4 ã€ã®ã°ã©ãã®äžã§èŸº 34 ãããã°ã©ãã«ã¯ãããã 1 ã€ãã€ç°ãªãã°ã©ããååšããã®ã§, èš 7 ã€ã®å šåæšãåŸããã.
(泚 1)
é£æ¥è¡åAãšç¹è¡åDã®éã«ã¯, 次ã«å®çŸ©ããè¡å ÎŽãä»ããŠäžè¬çãªé¢ä¿ãååšãã.è¡å ÎŽã¯ãã®èŠçŽ ÎŽij ã
ÎŽij =
{deg(vi) (i = jã®ãšã)
0 (i ï¿œ= jã®ãšã)(6.156)
ã§å®çŸ©ãããè¡åã§ãã, ãã®è¡åãš, é£æ¥è¡åA, ç¹è¡åDã®éã«ã¯
D = ÎŽ âA (6.157)
ãªãé¢ä¿ããã. åèªããã®æŒç¿åé¡ã§æ±ã£ãã°ã©ã Gã«ãããŠ, ãã®é¢ä¿åŒãæãç«ã£ãŠããããšã確èªããŠããããš.
(泚 2)
ããã§åãäžããç¹è¡åã®è¡ååŒãèšç®ããããšã«ãã, ã©ãã«ä»ãå šåæšã®æ°ãæ°ãäžããæ¹æ³ãç¹è¡ååŒæ³ãšåä»ãããšããã°, ãã®å šåæšã®åæ°ãåå®ããæ¹æ³ãšããŠã¯, ããäžã€, éè·¯è¡ååŒæ³ãšåŒã°ããæ¹æ³ããã. ããã§ã¯, ãã®æ¹æ³ã«é¢ããŠããã€ãã³ã¡ã³ãããŠããã.ãŸã, è¡åèŠçŽ Rij ã次ã®ããã«äžããããéè·¯è¡åRãå°å ¥ãã15 .
Rij =
{éè·¯ ci ãæ§æãã蟺ã®æ° (i = j)
± (éè·¯ ci ãš cj ã«å ±éãªèŸºã®æ¬æ°) (i ï¿œ= j)(6.158)
ããã§é察è§æåã®ç¬Šå·ã¯ ciãš cj ã®å ±éãªèŸºäžã§, ããã 2ã€ã®éè·¯ã®åããåãã§ããã°ãã©ã¹ã, éã§ããã°ãã€ãã¹ãéžã¶ããšã«çŽæãã.ãããš, ãã®éè·¯è¡åRãæããã°ã©ã Gã«é¢ããå šåæšã®ç·æ° Ï(G)ã¯
Ï(G) = |R| (6.159)
ã€ãŸã, è¡åRã®è¡ååŒã§äžãããã. ãã®æ¹æ³ã®æå¹æ§ã確èªããããã«, äŸé¡ 7.2 2 ã®é£æ¥è¡åã§äžããããã°ã©ã (å³ 6.130ã®ã°ã©ã G)ã«å¯ŸããŠ, ãã®æ¹æ³ãé©çšããŠã¿ãã.
15 ãã®è¬çŸ©ã«åºãŠãããã®ãšããŠã¯ 6 çªç®ã®ã°ã©ãè¡å.
ãã㯠121ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãŸã, ãã®ã°ã©ã Gã«ã¯éè·¯ c1, c2 ãååšã, ããããã¯ç¹ã®é åºã§ãã®åããæå®ããã°, c1 =12431, c2 = 343ãšãªã. åŸã£ãŠ, ãã®ã°ã©ã Gã®éè·¯è¡åRã¯
R =
(4 11 2
)(6.160)
ã§ãã. ãã£ãŠ, ãã®ã°ã©ã Gã«å¯Ÿããå šåæšã®ç·æ° Ï(G)ã¯
Ï(G) =â£â£â£â£ 4 1
1 2
â£â£â£â£ = 7 (6.161)
ãšãªã, ç¹è¡ååŒæ³ã«ããçµæ, ã€ãŸã, äŸé¡ 7.2 2.(2)ã®çããšäžèŽãã.ãšããã§, ããã°ã©ãGãäžãããããšã, ãã®å šåæšã®ç·æ°ãåå®ããå¿ èŠãçããé, äžè¿°ã®ç¹è¡ååŒæ³ãšéè·¯è¡ååŒæ³ã®ã©ã¡ãã䜿ã£ããããã®ã§ãããã ? ãã®çåã«å¯Ÿããäžè¬çãªçãã¯ã°ã©ã Gã«å«ãŸããç¹ã®æ°ãéè·¯ã®æ°ãããå°ãªãå Žåã«ã¯ç¹è¡ååŒæ³ãçšã, ãã®éã®å Žåã«ã¯
éè·¯è¡ååŒæ³ãçšããã®ããããšããããšã§ãã.äžèšæéã®æ£ããã確èªãããã, éè·¯è¡ååŒæ³ã®ç¹è¡åæ³ã«å¯Ÿãããåªäœæ§ããéç«ã£ãŠããããããªäŸãåããã, ãã®ã°ã©ãã«äž¡æ¹æ³ãé©çšããŠã¿ãããšã«ããã.å³ 6.132ã«ç€ºããã°ã©ãGã«å¯ŸããŠ, ãŸãã¯éè·¯è¡ååŒãé©çšããŠã¿ããš, ãã®å¹³é¢ã°ã©ãã®éè·¯ã¯ããããäžè§åœ¢ã§ãã, c1 = 1451, c2 = 3453, c3 = 1231ã§ãã. åŸã£ãŠ, ãã®ã°ã©ãã®éè·¯è¡å R
1 2
43
5c1
c2
c3
G
å³ 6.132: ããã§ç¹è¡ååŒæ³ãšéè·¯è¡ååŒæ³ãšã®èšç®ææ°ãæ¯èŒããããã«çšããã°ã©ã G.
ã¯
R =
âââ
3 1 01 3 00 0 3
âââ (6.162)
ãšãªã. ãã®è¡ååŒã¯çŽã¡ã«èšç®ã§ããŠ, ã°ã©ã Gã®å šåæšã®åæ°ã¯
Ï(G) =
â£â£â£â£â£â£â£3 1 01 3 00 0 3
â£â£â£â£â£â£â£ = 3â£â£â£â£ 3 1
1 3
â£â£â£â£ = 3à 8 = 24 (6.163)
ãšæ±ãŸã.äžæ¹ã§ç¹è¡ååŒæ³ã䜿ããšãªããš, ç¹è¡åãæ±ããªããã°ãªããªãã, ãã®ã°ã©ã㯠5ç¹ãããªãã°ã©ããªã®ã§, ç¹è¡åDã®ãµã€ãºã¯ 5à 5ã§ãã, å ·äœçã«æ¬¡ã®ããã«äžãããã.
D =
ââââââââ
3 â1 0 â1 â1â1 2 â1 0 00 â1 3 â1 â1â1 0 â1 3 â1â1 0 â1 â1 3
ââââââââ
(6.164)
ãã㯠122ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
åŸã£ãŠ, ãã®è¡åDã® 5è¡ 5åã«ãããäœå åã«ãã£ãŠã°ã©ã Gã®å šåæšã®æ¬æ°ãäžããããŠ
Ï(G) = (â1)5+5
â£â£â£â£â£â£â£â£â£â£
3 â1 0 â1â1 2 â1 00 â1 3 â1â1 0 â1 3
â£â£â£â£â£â£â£â£â£â£(6.165)
ãšãªã. ããã, èšç®ã®ææ°ããèšããš, ããããææã®åæ°ãæ±ããããã«ã¯äœå åå±éæ³çã䜿ã£ãŠè¡ååŒãèšç®ããªããã°ãªããªã. ããã§ã¯å®éã«å±éãå®è¡ã, è¡ååŒã®ãµã€ãºã段éçã«èœãšããŠãã£ãŠã¿ããš
Ï(G) = 3
â£â£â£â£â£â£â£2 â1 0â1 3 â10 â1 3
â£â£â£â£â£â£â£ +
â£â£â£â£â£â£â£â1 0 â1â1 3 â10 â1 3
â£â£â£â£â£â£â£ +
â£â£â£â£â£â£â£â1 0 â12 â1 0â1 3 â1
â£â£â£â£â£â£â£= 3
{2
â£â£â£â£â£ 3 â1â1 3
â£â£â£â£â£ +
â£â£â£â£â£ â1 0â1 3
â£â£â£â£â£}
+
{(â1)
â£â£â£â£â£ 3 â1â1 3
â£â£â£â£â£ +
â£â£â£â£â£ 0 â1â1 3
â£â£â£â£â£}
+
{(â1)
â£â£â£â£â£ â1 03 â1
â£â£â£â£â£ââ£â£â£â£â£ 2 â1â1 3
â£â£â£â£â£}
= 3{2Ã 8â 3}+ {â8â 1}+ {â1â 5} = 24
(6.166)
ãšãªã, 確ãã«éè·¯è¡ååŒæ³ã«ããçµæãšäžèŽãã. ããã, èšç®ã®æéã¯éè·¯è¡ååŒæ³ã®æ¹ãå°ãªãããšããããã§ããã.
ᅵ
ᅵ
ᅵ
ï¿œãäŸé¡ 7.4ã (2005幎床 æŒç¿åé¡ 7 )
ããè¡åæšå®çãçšã㊠Cayleyã®å®çã蚌æãã.
(解çäŸ)ãã®è¡åæšå®çãçšãã蚌æã§ã¯, åŸã«è¿°ã¹ãããã«å®å šã°ã©ã Kn ã®ç¹è¡åã®è¡ååŒãæ±ããããšãå¿
èŠãšãªãã®ã§, ãŸãã¯æºåãšããŠæ¬¡ã®ãããªmÃmã®å¯Ÿç§°è¡åã®è¡ååŒãæ±ããå ¬åŒãäœã£ãŠããããšã«ãã.
bm â¡
â£â£â£â£â£â£â£â£â£â£â£â£
a â1 â1 · · · â1â1 a â1 · · · â1â1 â1 a · · · â1· · · · · · · · · · · · · · ·â1 â1 â1 · · · a
â£â£â£â£â£â£â£â£â£â£â£â£=
â£â£â£â£â£â£â£â£â£â£â£â£
a+ 1 â1 â1 · · · â1â(a+ 1) a â1 · · · â1
0 â1 a · · · â1· · · · · · · · · · · · · · ·0 â1 â1 · · · a
â£â£â£â£â£â£â£â£â£â£â£â£= (a+ 1) bmâ1 + (a+ 1) cmâ1
(6.167)
ãã ã,äžä»ãã®æ·»ãåã¯ãã®è¡ååŒã®ãµã€ãºãè¡šã, cmâ1ã¯æ¬¡ã®ãããªæŒžååŒã§å®çŸ©ãããè¡ååŒã§ãã.
cmâ1 â¡
â£â£â£â£â£â£â£â£â£â£â£â£
â1 â1 â1 · · · â1â1 a â1 · · · â1â1 â1 a · · · â1· · · · · · · · · · · · · · ·â1 â1 â1 · · · a
â£â£â£â£â£â£â£â£â£â£â£â£=
â£â£â£â£â£â£â£â£â£â£â£â£
0 â1 â1 · · · â1â(a+ 1) a â1 · · · â1
0 â1 a · · · â1· · · · · · · · · · · · · · ·0 â1 â1 · · · a
â£â£â£â£â£â£â£â£â£â£â£â£= (1 + a) cmâ2 (6.168)
åŸã£ãŠ, bm ãæ±ããããã«ã¯ bm, cmâ1 ã«é¢ãã次ã®é£ç«æŒžååŒã解ãã°ãã.{bm = (a+ 1) bmâ1 + (a+ 1) cmâ1
cmâ1 = (a+ 1) cmâ2
(6.169)
ãã㯠123ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
cmâ1ã«é¢ãã挞ååŒã¯çŽã¡ã«è§£ããŠ, cmâ1 = (a+ 1)mâ2c1ãåŸãããã®ã§, ããã bmã«é¢ãã挞ååŒã«
ä»£å ¥ããã°, æ±ããã¹ã bmã¯ç°¡åã«
bm = (a+ 1)mâ1b1 + (mâ 1)(a+ 1)mâ1c1 (6.170)
ã®ããã«å®ãŸã. å®å šã°ã©ãã®å šåæšã®ç·æ°ã¯ãã®å ¬åŒ (6.170)ã§æ±ããããšãã§ãã. äŸãšããŠå®å šã°ã©ã K5,K6ã®ç¹è¡åã¯ãããã
DK5 =
ââââââââ
4 â1 â1 â1 â1â1 4 â1 â1 â1â1 â1 4 â1 â1â1 â1 â1 4 â1â1 â1 â1 â1 4
ââââââââ , DK6 =
âââââââââââ
5 â1 â1 â1 â1 â1â1 5 â1 â1 â1 â1â1 â1 5 â1 â1 â1â1 â1 â1 5 â1 â1â1 â1 â1 â1 5 â1â1 â1 â1 â1 â1 5
âââââââââââ
(6.171)
ãšæžãããšãã§ãã. åŸã£ãŠ, äžè¬ã«å®å šã°ã©ã Kn ã®å šåæšã®ç·æ°ã¯, åã«æ±ããå ¬åŒ (6.170)ã§
m = nâ 1, a = nâ 1, b1 = a, c1 = â1 (6.172)
ãšçœ®ãã°ããã®ã§, ãããã®å€ãä»£å ¥ããã°çŽã¡ã«
Ï(Kn) = bnâ1 = nnâ2 (6.173)
ãæ±ããå šåæšã®ç·æ°ã§ããããšãããã. å®å šã°ã©ã Kn ã®å šåæšãš nç¹ãããªãã©ãã«ä»ãæšã¯ 1察1ã«å¯Ÿå¿ããã®ã§, 以äžã«ãã, ã±ã€ãªãŒã®å®çãè¡åæšå®çãçšããŠèšŒæããããšãã§ãã.ï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 7.5ã (2006幎床 æŒç¿åé¡ 7 )
å®å šã°ã©ãKnããä»»æã® 1蟺 eãåé€ããããšã§åŸãããã°ã©ãKnâeã®å šåæšã®ç·æ° Ï(Knâe)ã¯
Ï(Kn â e) = (nâ 2)nnâ3
ã§äžããããããšã瀺ã.
[ãã³ã] å®å šã°ã©ãããä»»æã® 1蟺ãé€å»ããã°ã©ãã®ç¹è¡åãæ±ããŠè¡åæšå®çãçšãã. ãã®ãšãæ±ããè¡ååŒã¯äŸé¡ 7.4ã® bm, cm ãçšããŠæžããããšã«æ³šæãã.
(解çäŸ)
äŸãã°, å³ 6.133ã«äžããããã«å®å šã°ã©ã K5 ã®èŸºã 1æ¬åé€ãããã°ã©ãã®å šåæšã®ç·æ°ãæ±ããã.äŸãã°, å³ 6.133ã®ã°ã©ãã®å Žåã®ç¹è¡åã¯
DK5âe =
ââââââââ
3 0 â1 â1 â10 3 â1 â1 â1â1 â1 4 â1 â1â1 â1 â1 4 4â1 â1 â1 â1 4
ââââââââ
(6.174)
ãšãªã (â»ãã®å Žåã«ã¯èŸº 12ãé€å»ããã, ã©ã® 1蟺ãéžãŒãã, å®å šã°ã©ãã®å¯Ÿç§°æ§ããçµæã¯åãã«ãªãããšã«æ³šæ). åŸã£ãŠ, ãããäžè¬ã®å®å šã°ã©ãã«æ¡åŒµããã°
ãã㯠124ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
1
2
34
5
å³ 6.133: K5 â e ã®äžäŸ. ç Žç·ãåé€ãã蟺 e ã«è©²åœãã.
DKnâe =
âââââââââââ
aâ 1 0 â1 · · · â1 â10 aâ 1 â1 · · · â1 1â1 â1 a â1 · · · â1· · · · · · · · · · · · · · · · · ·· · · · · · · · · · · · · · · · · ·â1 â1 · · · · · · · · · a
âââââââââââ
(6.175)
ãšæžãã. åŸã£ãŠ, ãã®ç¹è¡åã®è¡ååŒãæ±ããããšãã§ããã°, ãããæ±ããå šåæšã®ç·æ°ã«ãªã£ãŠãã.ååã®äŸé¡ 7.4 ã§èŠãäœå åå±éãšåæ§ã®æç¶ããè¡ããš
Ï(Kn â e) = (â1)N+N |DKnâe(N â 1, N â 1)|
=
â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£
aâ 1 0 â1 · · · â1 â10 aâ 1 â1 · · · â1 â1â1 â1 a â1 · · · â1· · · · · · · · · · · · · · · · · ·· · · · · · · · · · · · · · · â1â1 â1 · · · · · · â1 a
â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£mÃm
=
â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£
aâ 1 0 â1 · · · â1 â1â(aâ 1) aâ 1 â1 · · · â1 â1â1 â1 a â1 · · · â10 · · · · · · · · · · · · · · ·0 · · · · · · · · · · · · â10 â1 · · · · · · â1 a
â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£mÃm
= (aâ 1)
â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£
aâ 1 â1 â1 · · · â1 â1â1 a â1 · · · â1 â1â1 â1 a â1 · · · â1· · · · · · · · · · · · · · · · · ·· · · · · · · · · · · · · · · â1â1 â1 · · · · · · â1 a
â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£(mâ1)Ã(mâ1)
+ (aâ 1)
â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£
0 â1 â1 · · · â1 â1â1 a â1 · · · â1 1â1 â1 a â1 · · · â1â1 · · · · · · · · · · · · · · ·â1 · · · · · · · · · · · · â1â1 â1 · · · · · · â1 a
â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£(mâ1)Ã(mâ1)
ãã㯠125ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
= (aâ 1)
â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£
a â1 â1 · · · â1 â1â(a+ 1) a â1 · · · â1 1
0 â1 a â1 · · · â10 â1 · · · · · · · · · · · ·0 â1 · · · · · · · · · â10 â1 · · · · · · â1 a
â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£(mâ1)Ã(mâ1)
+ (aâ 1)
â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£
1 â1 â1 · · · â1 â1â(a+ 1) a â1 · · · â1 1
0 â1 a â1 · · · â10 â1 · · · · · · · · · · · ·0 â1 · · · · · · · · · â10 â1 · · · · · · â1 a
â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£(mâ1)Ã(mâ1)
= (aâ 1){abmâ2 + (a+ 1)cmâ2}+ (aâ 1){bmâ2 + (a+ 1)cmâ2}= (aâ 1)(a+ 1)(bmâ2 + 2cmâ2) (6.176)
ãåŸããã. ããã§, è¡ååŒ bm, cm ã¯äŸé¡ 7.4 ã§çšããè¡ååŒã§ãã, 次ã®é£ç«æŒžååŒãæºãã{bm = (a+ 1) bmâ1 + (a+ 1) cmâ1
cmâ1 = (a+ 1) cmâ2
(6.177)
ãããã®è§£ã¯æ¬¡åŒã§äžããããããšãæãåºãã.{cmâ1 = (a+ 1)mâ2c1
bm = (a+ 1)mâ1b1 + (mâ 1)(a+ 1)mâ1c1(6.178)
åææ¡ä»¶ :
m = nâ 1, a = nâ 1, b1 = a, c1 = â1 (6.179)
ã«æ³šæããŠ, bmâ2, cmâ2 ã (6.176)åŒã«ä»£å ¥ããã°çŽã¡ã«
Ï(Kn â e) = n(nâ 2){(a+ 1)mâ3b1 + (mâ 3)(a+ 1)mâ3c1 + 2(a+ 1)mâ3c1}= n(nâ 2)(a+ 1)mâ3{b1 + c1(mâ 1)} = n(nâ 2)nnâ4 = (nâ 2)nnâ3 (6.180)
ãæ±ããå šåæšã®ç·æ°ã§ããããšãããã. åŸã£ãŠé¡æã瀺ããã.
ãã㯠126ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäžï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 7.6 ã (2006幎床æ å ±å·¥åŠæŒç¿ II(B) #1)
(1)ã°ã©ãH ã¯ãã®å šãŠã®é£æ¥ãã 2ç¹ã kåã®èŸºã§çµã°ããŠãããã®ãšãã. H ã«å«ãŸããå šãŠã®ã«ãŒããåãé€ã, å šãŠã®å€é蟺ã 1ã€ã®èŸºã«ãªããŸã§åé€ããŠã§ããã°ã©ã â åºåçŽã°ã©ã âãGãšãã. Gã®ç¹æ°, 蟺æ°ããããã n,mãšãããšã, ã°ã©ãG,H ã®å šåæšã®ç·æ° Ï(G), Ï(H)ã«é¢ããŠ
Ï(H) = knâ1Ï(G)
ãæãç«ã€ããšã瀺ã.(2) F ãã°ã©ãGã®å蟺ãå šãŠé·ã kã®éã§çœ®ãæããŠã§ããã°ã©ããšãã. ãã®ãšã
Ï(F ) = kmân+1Ï(G)
ã瀺ã.(3) (2)ã®çµæãçšããŠå®å šäºéšã°ã©ãK2,n ã®å šåæšã®ç·æ°ã¯
Ï(K2,n) = n · 2nâ1
ã§äžããããããšã瀺ã.
(解çäŸ)
(1)ã°ã©ãH ã§ã¯ä»»æã®é£æ¥ãã 2ç¹é㧠Gã§ã®èŸºã®ä»ã« k â 1æ¬ã®èŸºãååšããã®ã§, kæ¬ã®äžãã 1æ¬ãéžã³åºãæäœãèãããš, Gã®å šåæšã®èŸºæ°ã nâ 1ã§ãããã, ãã®çµã¿åãã㯠knâ1 éãã§
ãã. ããããã®æäœãç¹°ãè¿ããŠã§ãã Gã®å šåæšå šãŠã«åœãŠã¯ãŸãã®ã§, H ã®å šåæšã®ç·æ°ã¯
Ï(H) = knâ1Ï(G) (6.181)
ã§äžãããã.(2) Gã®èŸºã®äžã§ Gã®å šåæšã®èŸºãšããŠéžã°ãã蟺ã«è©²åœãã F ã§ã®èŸºã¯é·ã kã®éã§çœ®ãæãã£ãŠã
ãã, ãã®èŸºãé·ãã 1ã®é, ã€ãŸã, Gã®å šåæšã®èŸºãšãªããŸã§çž®çŽããæäœãèãããš, ãã®æäœã®ååŸã§ F ã®å šåæšãš Gã®å šåæšã®ç·æ°ã¯å€åããªãããšã«çç®ãã. ãããš, ãããã®ç·æ°ã«å€åãäžããèŠå ã¯Gã®èŸºã®äžã§å šåæšã®èŸºã«éžã°ããªãã£ã蟺ã«è©²åœãã F ã§ã®èŸºã®å¹æã§ãã. ã€ãŸã, F ã§ã®å蟺ã«ååšãã kâ 1åã®ç¹ã®ãã¡, ã©ã®ç¹ã§Gã§ã®ç¹ãžã®çž®çŽããšãããšããå Žåã®æ°ã¯
kéãã§ãã, Gã®èŸºã®äžã§å šåæšã®èŸºã«éžã°ããªãã£ã蟺æ°ã¯mâ (nâ 1)ã§ãããã, çµå±
Ï(F ) = kmân+1Ï(G) (6.182)
ãšãªã.(3) 2ã€ã®ç¹ã næ¬ã®èŸºã§çµãã ã°ã©ããGãšããã. ãã®å蟺ãå šãŠé·ãã 2ã®éã§çœ®ãæãã. ãã®ã°ã©ãã F ãšãã. ãã®å€æ: Gâ F ã§å¢å ãã nåã®ç¹ã¯å šãŠå ã® 2ç¹ãšé£æ¥ã, äºãã«é£æ¥ããªãã®ã§å®å šäºéšã°ã©ãK2,nãšãªã (å³ 6.134åç §). åŸã£ãŠ, (2)ã§ã®çµæãçšãããšä»ã®å Žå Ï(G) = n
ã§ããããšã«æ³šæããŠ
Ï(K2,n) = Ï(F ) = 2nâ2+1Ï(G) = 2nâ1 · n (6.183)
ãåŸããã.
ãã㯠127ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
å³ 6.134: ããã§èããã°ã©ã F (å·Š) ãšãã®ååã°ã©ãã§ããå®å šäºéšã°ã©ã K2,n(å³).
ᅵ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 7.7 (2006幎床æ å ±å·¥åŠæŒç¿ II(B) #1)
næ¬ã®ã¹ããŒã¯ãæã€è»èŒªã°ã©ãã®å šåæšã®ç·æ°ãwnãšãããš
wn â 4wnâ1 + 4wnâ2 â wnâ3 = 0
ãæãç«ã€ããšã瀺ã, wn ãæ±ãã.
(解çäŸ)
ãŸã㯠næ¬ã®ã¹ããŒã¯ãæã€è»èŒªã®ç¹è¡åDã¯
D =
âââââââââââ
n â1 â1 · · · â1 â1â1 3 â1 · · · 0 â1â1 â1 3 · · · 0 0· · · · · · · · · · · · · · · · · ·â1 0 0 · · · 3 â1â1 â1 0 · · · â1 3
âââââââââââ
nÃn
(6.184)
ã§ãã. äœå åå±éæ³ãçšããŠ, wn = |D(1, 1)|ãèšç®ãããš
wn = 3anâ1 + 2bnâ1 (6.185)
ãåŸããã. ããã«, an ã¯æ¬¡ã§å®çŸ©ãã, ããã§ããŸãäœå åå±éãè¡ããšæ¬¡åŒã®ãããªæŒžååŒã«åŸã.
an =
â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£
3 â1 0 · · · 0 0â1 3 0 · · · 0 00 0 3 · · · 0 0· · · · · · · · · · · · · · · · · ·0 0 0 · · · 3 â10 0 0 · · · â1 3
â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£nÃn
= 3anâ1 â anâ2 (6.186)
bn ããŸã次ã®ããã«å®çŸ©ãã, ããã§ããŸãäœå åå±éãçšãããšæ¬¡ã®æŒžååŒã«åŸã.
bn =
â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£
â1 0 0 · · · 0 â1â1 3 â1 · · · 0 00 â1 3 · · · 0 0· · · · · · · · · · · · · · · · · ·0 0 0 · · · 3 â10 0 0 · · · â1 3
â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£nÃn
= âanâ1 + bnâ1 + anâ2 (6.187)
ãã㯠128ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãã®æŒžååŒã¯æ¬¡ã®ããã«æžãçŽãããšãã§ããŠ, bn + anâ1 ã¯åé ã b3 + a2, å ¬æ¯ 1ã®çæ¯æ°åãªã®ã§
bn + anâ1 = b3 + a2 =
â£â£â£â£â£â£â£â1 0 â1â1 3 â10 â1 3
â£â£â£â£â£â£â£ +
â£â£â£â£â£ 3 â1â1 3
â£â£â£â£â£ = â1 (6.188)
ãæãç«ã€. åŸã£ãŠ, ããšã¯é£ç«æŒžååŒ (6.185)(6.186)(6.188)ã wn ã«é¢ããŠè§£ã, å®éã«åé¡ã§äžããããé¢ä¿åŒãæç«ããããšã瀺ãã°ãã. å®éã«è§£ããš, α = (3 +
â5)/2, β = (3ââ5)/2 ãšããŠ
wn = αn + βn â 2 = 3(αnâ1 + βnâ1 â 2)â (αnâ2 + βnâ2 â 2) + 2
= 3wnâ1 â wnâ2 + 2 (6.189)
ãšãªãã, ãããšãã®åŒã§ nâ n+ 1ãšãããã®ã蟺ã åŒããš
wn â 4wnâ1 + 4wnâ2 â wnâ3 = 0 (6.190)
ãåŸããã. ããã¯ããã§ç€ºãã¹ã挞ååŒã§ãã.ï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 7.8 ã (2004幎床æ å ±å·¥åŠæŒç¿ II(B) #1)
å³ 6.135ã®ã°ã©ã Gã«å¯Ÿã, 以äžã®åãã«çãã.
(1)ã°ã©ã Gããå šåæš Tãäœã£ããšããã. ãã®ãšã, Tã®èŸºæ°ãæ±ãã.(2) (1)ã§å šåæšãäœããŸã§ã«åé€ããªããã°ãªããªã蟺æ°mãæ±ãã.(3) Tã« (2)ã§æ±ãã蟺ã 1ã€ãã€ä»å ãããšå¿ ãéè·¯ã 1ã€ã ãã§ãã. ãã®ããã«ããŠäœãããéè·¯ãåºæ¬éè·¯ãšåŒã¶ã, ãã®åºæ¬éè·¯ãmåå šãŠæã.
(4) (3)ã§æ±ããéè·¯ C1, C2, · · · , Cm ã«å¯Ÿã, éè·¯è¡åæ³ãçšããããšã«ãã, å šåæšã®ç·æ° Ï(G)ãæ±ãã.
1
2
3 4
5
6
å³ 6.135: ããã§å šåæšãèããã°ã©ã G.
(解çäŸ)
(1) 5æ¬(2) m = 4(3)åºæ¬éè·¯ 4〠C1, C2, C3, C4 ãæããšå³ 6.136ã®ããã«ãªã.
ãã㯠129ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
C1
1
2
3
C2
1
3
6
5
C3
6
3 4
C4
5
6
4
å³ 6.136: æ±ããåºæ¬éè·¯. éè·¯è¡ååŒæ³ãçšããããã«, åéè·¯ã«ã¯å³ã®ããã«åãä»ããããŠãã.
(4)ã°ã©ã Gã®éè·¯è¡åR㯠(3)ã§æ±ããåºæ¬éè·¯ã«æ³šæããŠ
R =
ââââââââ
3 â1 0 0â1 4 â1 â10 â1 3 â10 â1 3 â10 â1 â1 3
ââââââââ
(6.191)
ãšæžããã®ã§, å šåæšã®ç·æ° Ï(G)ã¯
Ï(G) = |G| = 3
â£â£â£â£â£â£â£4 â1 â1â1 3 â1â1 â1 3
â£â£â£â£â£â£â£â (â1)
â£â£â£â£â£â£â£â1 0 0â1 3 â1â1 â1 3
â£â£â£â£â£â£â£= 3
{4
â£â£â£â£â£ 3 â1â1 3
â£â£â£â£â£â (â1)
â£â£â£â£â£ â1 â1â1 3
â£â£â£â£â£ââ£â£â£â£â£ â1 â1
3 â1
â£â£â£â£â£}ââ£â£â£â£â£ 3 â1â1 3
â£â£â£â£â£= 64 (å) (6.192)
ã§ãã.
ãã㯠130ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäžï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 7.9 ã (2004幎床æ å ±å·¥åŠæŒç¿ II(B) #1)
å³ 6.137ã®ããã« 1ç¹ãã kæ¬ã®æãåºã, ãã® kæ¬ã®æããããã« kæ¬ã®æãåºããšããæäœã n
åç¹°ãè¿ããŠã§ããæšã Tk(n)ãšåä»ããã. å³ 6.137ã®äŸã¯ T3(2)ã§ãã. ãã®ãšã, 次ã®åãã«çãã.
(1) T3(n) ã«å«ãŸããç¹ã®ç·æ° S3(n) ãæ±ãã. ãŸã, T3(n) ã®ç«¯ç¹ã®ç·æ°ã Q3(n) ãæ±ã, æ¯P3(n) = Q3(n)/S3(n)ã«å¯Ÿã, 極éå€ :
p3 = limnââP3(n)
ãèšç®ãã.
(2) (1)ãåèã«ããŠ, ä»»æã®èªç¶æ°K ã«å¯Ÿã㊠PK(n)ãèšç®ã, nã«é¢ãã極éå€ :
pK = limnââPK(n)
ãæ±ã, ããã«K ã«é¢ãã極éå€ :
pâ = limKââ
pK
ãèšç®ã, æš TK(n)ã®æ§é ãšæ¥µéå€ pâ ãããããããšãç°¡æœã«è¿°ã¹ã.
(泚) : nãšèšããšæ®éã¯ã°ã©ãã®ç¹ã®æ°ã瀺ããŸãã, ããã§ã¯ãæäœãã®åæ°ã§ããããšã«æ³šæ.
T 3 (2)
å³ 6.137: ããã§è¿°ã¹ããæäœãã«ãã£ãŠäœãããæš T3(2).
(解çäŸ)
(1)æããã«, S3(n)ã¯åé 1, å ¬æ¯ 3ã®çæ¯æ°åã®ç¬¬ né ãŸã§ã®åã§ãããã
S3(n) = 1 + 3 + 32 + · · ·+ 3n =3n+1 â 1
3(6.193)
ã§ãã. äžæ¹, T3(n)ã®ç«¯ç¹ã®ç·æ° Q3(n)㯠T3(n)ã®äœãæ¹ããæããã« Q3(n) = 3n ã§ããã®ã§, ãããã®æ¯ P3(n) = Q3(n)/S3(n)ã¯
P3(n) =2 · 3n
3n+1 â 1(6.194)
ãã㯠131ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ã§ãã, åé¡ã®æ¥µéå€ã¯
p3 = limnââP3(n) =
23
(6.195)
ãšæ±ãŸã.
(2) k = K ã®å Žåã«ã¯
SK(n) =Kn+1 â 1K â 1
(6.196)
QK(n) = Kn (6.197)
PK(n) =(K â 1)Kn
Kn+1 â 1(6.198)
ãšãªãã®ã§, PK(n)ã«é¢ã㊠nââã®æ¥µéããšããš
pK = limnââPK(n) =
K â 1K
(6.199)
ãåŸããã (K = 3ãšçœ®ãã° (1)ã®çµæãšäžèŽããããšã«æ³šæ). ããã«, ãã®ç¢ºçã§K â âã®æ¥µéããšãã° pKââ = 1 ãåŸãããã, ãã®çµæã¯ã»ãšãã©å šãŠã®ç¹ãæšã®æ«ç«¯ã«ååžããŠãã, äžå¿ãããã®æ«ç«¯ã«è³ããŸã§ã®éã«ååšããç¹ã®æ°ã¯æ«ç«¯ã®ç¹æ°ãšæ¯ã¹ãŠç¡èŠã§ããã»ã©å°ãªãããšãæå³
ããŠãã. æ«ç«¯ãå¯ã«è©°ãŸã£ãŠããã®ã«å¯ŸããŠ, äžå¿ããæ«ç«¯ã«ããããŸã§ã®éãã¹ã«ã¹ã«ã®ç¶æ ãªããã§ãã. ã¡ãªã¿ã«, ãã®ãããªäœãæ¹ã§åºæ¥äžããæšã®ããšãã±ãŒãªãŒã®æš (Caleyâs tree)ãšåŒãã§ãã.
ᅵ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 7.10 ã (2005幎床æ å ±å·¥åŠæŒç¿ II(B) #2)
è¡åæšå®çãçšããŠå®å šäºéšã°ã©ãKm,n ã®å šåæšã®ç·æ°ã
Ï(Km,n) = mnâ1nmâ1
ã§äžããããããšã蚌æãã.
(解çäŸ)å®å šäºéšã°ã©ãKm,nã®ç¹è¡åDã¯æ¬¡ã®ãµã€ãº (m+ n)à (m+ n)ã®æ£æ¹è¡åã§ãã.
D =
âââââââââââââââââ
n 0 · · · 00 n · · · 0...
. . . . . .... â1
0 · · · · · · n
m 0 · · · 00 m · · · 0
â1...
. . . . . ....
0 · · · · · · n
âââââââââââââââââ
(6.200)
ãã㯠132ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
åŸã£ãŠ, 以äžã§ã¯ããç ©éã§ã¯ããã, ãã®ç¹è¡åã®ç¬¬ (1, 1)æåã§ã®äœå å:
|D(1, 1)| =
â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£
n 0 · · · 00 n · · · 0...
. . . . . .... â1
0 · · · · · · n
m 0 · · · 00 m · · · 0
â1...
. . . . . ....
0 · · · · · · n
â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£â£
(6.201)
ãäžå¯§ã«èšç®ããŠããããšã«ãªã. ããã«, å·Šäžãšå³äžã®éšåè¡å:
ââââââ
n 0 · · · 00 n · · · 0...
. . . . . ....
0 · · · · · · n
ââââââ ,
ââââââ
m 0 · · · 00 m · · · 0...
. . . . . ....
0 · · · · · · m
ââââââ (6.202)
ã®ãµã€ãºã¯ãããã, (mâ 1)à (mâ 1), nà nã§ããããšã«æ³šæããã.ããã§, 次ã®ãããªè¡åã®åºæ¬å€åœ¢ãè¡ã. ããªãã¡, 第måãã第 (m+ nâ 2)åãŸã§ã® (nâ 1)åã®
åãã¯ãã«ã第 (m+ nâ 1)åã«å ç®ã, 次ãã§, 第 (m+ nâ 1)åã« 1/mãä¹ãããã¯ãã«ã第 1åãã第 (mâ 1)åãŸã§å ç®ãã. ãã®æäœã«ãã
|D(1, 1)| = mn
â£â£â£â£â£â£â£â£nmâ1
m ân 1m
. . .
ân 1m nmâ1
m
â£â£â£â£â£â£â£â£(6.203)
ãåŸããã. ãã以éã¯ãã®è¡ååŒãäžäžè§è¡åã«ããããã«åºæ¬å€åœ¢ãç¹°ãè¿ã.ãŸãã¯, ãã®ç¬¬ 1è¡ã« 1/(mâ 1)ãä¹ããè¡ãã¯ãã«ã第 2è¡ãã第 (mâ 1)è¡ãŸã§å ç®ãããš
|D(1, 1)| = mn
â£â£â£â£â£â£â£â£â£â£
nmâ1m â â â0 nmâ2
mâ1 ân 1mâ1
.... . .
0 ân 1mâ1 nmâ2
mâ1
â£â£â£â£â£â£â£â£â£â£(6.204)
ãåŸãããã, ãã以é, 第 iè¡ã« 1/(mâ i)ãä¹ããè¡ãã¯ãã«ã第 (i+ 1)è¡ä»¥éã«å ç®ãããšããæäœã i = 2ãã i = mâ 2ãŸã§é 次繰ãè¿ãããšã§ææã®è¡ååŒ |D(1, 1)|ã
|D(1, 1)| = mn
â£â£â£â£â£â£â£â£â£â£
nmâ1m â â â0 nmâ2
mâ1 ân 1mâ1
... 0. . .
0 0 n 12
â£â£â£â£â£â£â£â£â£â£= mn · nmâ1 · 1
m= mnâ1nmâ1 (6.205)
ãšèšç®ããã.åŸã£ãŠ, è¡åæšå®çããå®å šäºéšã°ã©ãã®å šåæšã®ç·æ°ãmnâ1nmâ1 ã§ããããšã蚌æããã.
â» å®å šäºéšã°ã©ãã®å¯Ÿç§°æ§ãèãããš, ããå°ãã¹ããŒããªæ°ãäžãæ¹ãã§ãããããããªãã, çŸæç¹ã§æãã€ãè€éã§ã¯ãããå°éãªæ°ãäžãæ¹ã¯äžã«ç€ºããç¹è¡åã®äœå åèšç®ã§ãã.
ãã㯠133ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ᅵ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 7.11 ã (2007幎床 æŒç¿åé¡ 7 )
è (æ«ç«¯)ã®æ°ã nã§ãã 2åæš (äžã€ã®æãã 2ã€ã®æã䌞ã³ãæš)ã®ç·æ°ã pn ãšããã. ãããšæããã« p0 = 0, p1 = p2 = 1ã§ãã. ãã®ãšã以äžã®åãã«çãã.
(1) p3 = 2ã§ãã. ãã® 2ã€ã® 2åæšãæã.(2) p4ãæ±ã, ãã®å šãŠã® 2åæšãæã.(3)èæ° n1ã® 2åæšãšèæ° n2ã® 2åæšã®äºãã®æ ¹ (2åæšã®éå§ç¹)ã 1ã€ã®æ°ããæ ¹ãä»ããŠã€ãªããæäœã§èæ° n1 + n2 ã® 2åæšã pn1pn2 éãã§ãã. n1 = 3, n2 = 4ã®å Žåã«å¯Ÿã, ãã®æäœã§ã§ãã 2åæšãå šãŠæã.
(4) xãä»»æã®å®æ°ãšãã. xã® n次ã®åªä¿æ°ãèæ° nã® 2åæšã®ç·æ° pnã«ãªãããã«ããŠäœããã次
ã®å€é åŒ:
P (x) = p0 + p1x+ p2x2 + · · ·+ pnx
n + · · ·
ãã2åæšçæå€é åŒããšåã¥ããããšã«ããã. ãããš, åå (3)ã§äžããæäœã§ã§ãã 2åæšã®ç·æ° pn1pn2 㯠2åæšçæå€é åŒã® 2ä¹, ã€ãŸã, {P (x)}2ã«ããã xn1+n2 ã®ä¿æ°ã®äžéšåãšããŠçŸ
ãã (åã n1 + n2ãäžãã n1 ãš n2ã®çµã¿åããã¯è€æ°ããã®ã§ãäžéšåãã§ãã). ãã®äºå®ããµãŸããèå¯ã«ãã
P (x) = x+ {P (x)}2 (6.206)
ãæãç«ã€ããšã瀺ã.(5) (4)ã§ç€ºããé¢ä¿åŒ (6.206)ãã pn ã nã®é¢æ°ãšããŠæ±ãã.
(解çäŸ)
ããã§ã®æçµçãªç®æšã¯èæ° nã® 2åæšã®ç·æ° pn ãæ±ããããšã«ãã (â» nã¯ãèæ°ãã§ãã, ãç¹æ°ãã§ãªãããšã«æ³šæ). 次ã®æé ã«åŸã£ãŠèå¯ãé²ã, ãã®ç·æ°ãæ±ããŠã¿ãããšã«ããã.
(1)èæ° 3ã® 2åæšã®ç·æ°ã¯ p3 = 2ã§ããã, ãããå®éã«æããŠã¿ããšå³ 6.138ã®ããã«ãªã.
1 2
3 1
2 3
å³ 6.138: èæ° 3 ã® 2 åæš.
(4)èæ° 4ã® 2åæšã®ç·æ°ãæ°ããããšã«ãã. å®éã«æãåºããŠã¿ããš, å³ 6.139ã®ãã㪠5ã€ã® 2åæšãåŸããã. åŸã£ãŠ, p4 = 5ã§ãã.
(3) (1)(2)ã®çµæãã, èæ° 3,4ã® 2åæšã®ç·æ°ããããã p3 = 2, p4 = 5ã§ããããšãããã£ãã®ã§, åé¡ã«äžããããæäœã«ãã£ãŠåŸããã 2åæšã®ç·æ°ã¯ p3 à p4 = 10åããã¯ãã§ãã. å®éã«, ãã® 2åæšã®èæ°ã¯ 3 + 4 = 7ã§ããããšã«æ³šæããŠæãã ããŠã¿ããšå³ 6.140ã®ããã«ãªã.
(4) (3)ã§åºæ¥äžãã 2åæšã¯èæ° 7ã®ã°ã©ãã§ããã, åå (3) ã§èããæäœã®ãéæäœãã€ãŸã, èæ°7ã® 2åæšããã®æ ¹ããèæ° 3, 4ã® 2ã€ã® 2åæšã«å解ããæäœãèãããš, èæ° 7ã® 2åæšã®ç·æ°ã®ãã¡, èæ° 3, 4ãžãšå解ããããã®ã¯ãã®äžéšåã§ããããšãããã. å®é, ãã®éæäœã«ãããå
ãã㯠134ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
1 2 3 4
1 2
3
4
1
23
4
1
2 3
4
1
2
3 4
å³ 6.139: èæ° 5 ã® 2 åæš.
1 2 3 4 5 6
7
1 2 3 4
5
6 7
1 2
3
4
5 6
7
1 2
3
4 5
6 7 1
2 3
4
5 6
7
1
2 3
4 5
6 7
1
2 3
4 5 6
7 1
2 3
4
5
67
1
2
3 4
5 6
7
1
2
3 4
5
6 7
å³ 6.140: ããã§èããæäœã«ãã£ãŠã§ããèæ° 7 ã® 2 åæš. æ ¹ã«æ¥ç¶ããå·ŠåŽã® 2 åæšãèæ° 4 ããã®ãã®ã§ãã, å³åŽãèæ°3 ããã®ãã®.
解ã®ä»æ¹ãšããŠã¯ä»ã« (1, 6), (6, 1), (2, 5), (5, 2), (0, 7), (7, 0)ãããããã§ãã. åŸã£ãŠ, åé¡ã«äžããã2åæšçæå€é åŒãP (x)ã® xã«é¢ãã n次ã®åªä¿æ°ã«ãèæ° nã® 2åæšã®ç·æ°ããšããæå³åããæããããš, ãã®å€é åŒã® 2ä¹ {P (x)}2ã®äžã«çŸãã x7ã®ä¿æ°ã«ã¯äžã«æããå解ã®ä»æ¹ã«å¯Ÿå¿ãã
p1p6, p6p1, p2p5, p5p2, p0p7, p7p0, p3p4, p4p3ãçŸããããšã«ãªã.ãšããã§, ããã§èããæäœãæ°ããæ ¹ãä»ã㊠2ã€ã® 2åæšãã€ãªããŠ, ãµã€ãºã®ãã倧ã㪠2åæšãäœããããšã«ãã£ãŠ, å šãŠã®èæ°ãæ〠2åæšãåçç£ã§ããªããã©ãããèããŠã¿ããš, æããã«èæ° 1ã® 2åæšãäœãããšã¯ã§ããªã. ããã¯èæ° 1ã® 2åæšããã®éæäœã§ 2ã€ã® 2åæšãäœãããšãã§ããªãããšãèãããšæããã§ãã. åŸã£ãŠ, {P (x)}2㯠P (x)ã®å šãŠã®åª (2åæš)ãåçŸã§ãã, {P (x)}2ã« xã足ãããšã§ P (x)ãåçŸããã (ä»»æã®èæ°ã® 2åæšãäœãããšãã§ãã). ãã£ãŠ,次ã®é¢ä¿åŒ:
P (x) = x+ {P (x)}2 (6.207)
ãæãç«ã€ããšã«ãªã.
ãã㯠135ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
(5) (4)ã§ç€ºãããé¢ä¿åŒã«å ·äœçã« P (x)ã® xã«é¢ããå€é åŒãä»£å ¥ããŠã¿ããš
p0 + p1x+ p2x2 + · · ·+ pnx
n + · · · = x+ {p0 + p1x+ p2x2 + · · ·+ pnx
n + · · ·}2 (6.208)
ãåŸãããã, ãã®çåŒãæãç«ã€ããã«ã¯å šãŠã® xã®åªä¿æ°ãäžèŽããããšãå¿ èŠã§ãã. ãã®æ¡ä»¶ã x0, x, x2, x3, x4ã®åªä¿æ°ã«å¯ŸããŠæžãäžããŠã¿ããš
p0 = p20 (6.209)
p1 = 1 + 2p1p0 (6.210)
p2 = 2p0p2 + p21 (6.211)
p3 = 2p0p3 + 2p1p2 (6.212)
p4 = 2p0p4 + 2p1p3 + p22 (6.213)
ãšãªãã, èªæãªäºå® p0 = 0(ãæ ¹ãã®ã¿ãååšã, ãèããäžã€ãç¡ãå Žå. ã€ãŸã, å€ç«ç¹äžåã®å Žå)ã«æ³šæãããš, é次, ãã®æ¹çšåŒã解ãããšã«ãã, p1 = p2 = 1, p3 = 2, p4 = 5ãæ±ãããã. ãã㯠2åæšãå®éã«æããå Žåã®èå¯çµæãšäžèŽãã.ããã§, (6.208)åŒãä»»æã® xã«å¯ŸããŠæãç«ã€ããšãèããŠ, 圢åŒçã« (6.208)åŒã P (x)ã«ã€ããŠè§£ããŠã¿ããš
P (x) =1±â1â 4x
2(6.214)
ãåŸãããã, P (x)ã xã«é¢ããåªçŽæ°ã§äžããããããšãæãåºã, xï¿œ 1ã®äžã§â
1â 4xãããŒã©ãŒå±éããŠã¿ããš
â1â 4x = 1â 2xâ
ââi=2
âik=1(2k â 3)i! 2i
(4x)i (6.215)
ãšãªãã®ã§, å±éä¿æ° (ã€ãŸã, 2åæšã®æ°)ã¯å šãŠæ£ã®å€ããšãããšã«æ³šæããã°, (6.214)ã® 2ã€ã®è§£ã®ãã¡ P (x) = (1ââ1â 4x)/2ã®ã¿ãæ¡çšãã
P (x) = x+12
ââi=2
âik=1(2k â 3)i! 2i
(4x)i (6.216)
ãåŸããã. ãããå°ãæŽçããã°
P (x) = x+ââ
i=2
2iâ1âi
k=2(2k â 3)i!
xi =ââ
i=1
2iâ1(2iâ 3)!!i!
xi (6.217)
ãšãªã. ãã ã, ããã§ã¯ (2iâ 3)!! = (2iâ 3)(2iâ 5) · · · 5 · 3 · 1, (â1)!! = 1ãšå®çŸ©ããããšã«æ³šæãããã. åŸã£ãŠ nåã®èãããªã 2åæšã®ç·æ°ã¯, äžåŒå³èŸºã®åã«ããã i = nã®é ã®ä¿æ°ã§ãã
pn =2nâ1(2nâ 3)!!
n!(6.218)
ãšãªã.ããã§æ©é, å ·äœçã«ã¯ããã®æ°é ã確ãããŠã¿ããš, p1 = 21â1(â1)!!/1! = 1, p2 = 22â1(1)!!/2! =1, p3 = 23â13!!/3! = 2, p4 = 24â15!!/4! = 5 ãšãªã, 確ãã«åã«æ±ããçµæã«äžèŽãã.ããã§ã¯ n = 7ã®å Žåã¯ã©ãã§ãããã? å ·äœçã«äžã§æ±ããå ¬åŒ (6.218)ã« n = 7ãä»£å ¥ããŠã¿ããš
p7 =27â111!!
7!=
26 · 11 · 9 · 7 · 5 · 3 · 17 · 6 · 5 · 4 · 3 · 2 · 1 = 12 · 11 = 132 (6.219)
ãã㯠136ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãåŸããã. åã« n = 3ã® 2åæšãš n = 4ã® 2åæšãæ°ããæ ¹ãä»ããŠã€ãªããæäœã§ p3p4 = 10åã® 2åæšãã§ããããšãèŠãã, èæ°ã 7ã§ãã 2åæšã®ç·æ°ã¯ 132ã§ããããšãã, 確ãã«ãã®æäœã§äœããã 2åæšã¯èæ° 7ã® 2åæšå šäœã®ãäžéšåã, ã€ãŸã, 10/132ã ãã®å²åãšãªã£ãŠãã.ãã£ãããªã®ã§, ããã§åŸãããçµæ (6.218)ãå ¬åŒåããŠããã.
èæ° nã® 2åæšã®ç·æ°ã¯2nâ1(2nâ 3)!!
n!ã§äžãããã. ãã ã, (2nâ 3)!! = (2nâ 3)(2nâ 5) · · · 3 · 1, (â1)!! = 1ã§ãã.
æ¢ã«ã¿ã äŸé¡ 3.8 ã§ã¯ãæ©éçæè¡åããå°å ¥ã, ä»»æã®ã°ã©ãã®æ©éã®åæ°ãé£æ¥è¡åã®åªä¹ã®ä¿æ°ãšæ©éæ°ã察å¿ä»ããŠèšç®ããã, ããã§ãã2åæšçæå€é åŒããå°å ¥ã, ãã®åªå±éä¿æ°ã« 2åæšã®åæ°ã察å¿ä»ããããŠèæ°ãäžããããå Žåã® 2åæšã®ç·æ°ãèšç®ãã. ãã®æã®æ¹æ³ã¯æããã«ã°ã©ããæããŠæ°ãæ°ãäžãããããå¹çãè¯ã.
ãã㯠137ããŒãžç®
139
第8åè¬çŸ©
8.1 å¹³é¢æ§
ããã§ã¯ã°ã©ãã®å¹³é¢æ§, ã€ãŸã, äžè¬ã®ã°ã©ããå¹³é¢å ã«ã©ã®èŸºã亀差ããããšãªãæãããšã®ã§ããæ¡ä»¶ã«ã€ããŠåŠã¶. ãŸã, ãã®ããã«ããŠæããã°ã©ã â å¹³é¢ã°ã©ã â ã®æ§è³ª, åã³, äžããããã°ã©ãã®ãå¹³é¢ãžã®æãããããã枬ãææšã§ããã亀差æ°ããåããã«ã€ããŠã詳ããèŠãŠè¡ãããšã«ãã.
8.1.1 å¹³é¢ã°ã©ããšãªã€ã©ãŒã®å ¬åŒ
å¹³é¢ã°ã©ã (planar graph) : ã©ã® 2ã€ã®èŸºã, ãããæ¥ç¶ããç¹ä»¥å€ã§ã¯å¹ŸäœåŠçã«äº€å·®ããªãããã«æãããã°ã©ã (å³ 8.141åç §).
å³ 8.141: å¹³é¢ã°ã©ãã®äŸ. äž¡è ã¯äœçžå圢ã§ããã, å³ã®ãããªæç»ã«ãããŠå¹³é¢ã°ã©ããšããã.
é¢ (face) : 蟺ã«ãã£ãŠåå²ãããé åå³ 8.142ã«ãããŠ, éæçãªé¢ f4ã¯ç¡éé¢ (infinite face) ãšåŒã°ãã.
f1
f2
f8
f7
f3
f5
f6
f4
å³ 8.142: 8 ã€ã®é åã«åå²ãããå¹³é¢ã°ã©ã. ãããé åã®äžã§, f4 ã¯ç¡éé¢ã§ãã.
äžããããã°ã©ãGãç¹æ° n, 蟺æ°m, é¢æ° f ã§ç¹åŸŽä»ããããšã«ãããš, ãããã®éã®éã«ãããªãé¢ä¿ããããšã, ã°ã©ã Gã¯å¹³é¢ãžåã蟌ã¿å¯èœã§ãã, å¹³é¢ã°ã©ããšãªãããã§ãããã ? ãã®çãã¯ãªã€ã©ãŒã«ãã£ãŠæ¬¡ã®å®ç (å ¬åŒ)ãšããŠãŸãšããããŠãã.
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
å®ç 13.1 (ãªã€ã©ãŒã®å ¬åŒ)
ã°ã©ã Gãé£çµãªå¹³é¢ã°ã©ããšãããšã, 次ã®å ¬åŒãæãç«ã€.
nâm+ f = 2 (8.220)
(蚌æ)蟺æ°mã«é¢ããæ°åŠçåž°çŽæ³ã§èšŒæãã.m = 0ã®ãšã, ç¹æ°ã 1ã€ã ãã®çŽ ã°ã©ãã§ãããã n = 1ã§ãã, é¢ã¯ç¡éé¢ã 1ã€, ã€ãŸã, f = 1ã§ãã. åŸã£ãŠ
nâm+ f = 1â 0 + 1 = 2
ãšãªã, é¢ä¿åŒãæç«ãã.
åŸã£ãŠ, 以äžã§ã¯m ï¿œ= 0ã®ãšããèãã. ãã®ãšãåž°çŽæ³ã®ä»®å®ãšããŠ
ãmâ 1æ¬ä»¥äžã®èŸºãæã€å šãŠã®ã°ã©ã Gã«ã€ã㊠(8.220)ãæãç«ã€ã
ãšããŠã¿ãã. ãã®ä»®å®ã®ããšã§, 蟺æ°mã®ã°ã©ãã«å¯ŸããŠãé¢ä¿åŒ (8.220)ã®æç«ã瀺ããã°èšŒæã¯çµäºã§ãã.
ã°ã©ãGãæšã®å Žåã«ã¯, mæ¬ã®èŸºãæã€ãšãããš, åœç¶ã®ããšãªããm = nâ 1, f = 1(ç¡éé¢) ã§ãããã, é¢ä¿åŒ (8.220)ã¯
nâm+ f = nâ (nâ 1) + 1 = 2
ãšãªã, 蟺æ°mã«å¯ŸããŠæç«ãã.
äžæ¹, ã°ã©ã Gãæšã§ã¯ãªãå Žå. ã°ã©ã Gã®ä»»æã®èŸºãåé€ããå Žå, 蟺æ°, ç¹æ°, é¢æ°ã¯ããããã©
f1
f2
f8
f7
f3
f5
f6
f4
cut
å³ 8.143: ã°ã©ãã®ä»»æã®èŸºãåé€ããå Žåã®èŸº, ç¹, é¢ã®æ°ã®å€åéãèãã. ãã®ã°ã©ãã«é¢ããŠèšãã°, åé€å : n = 9, m =15, f = 8ã§ãã, 9â 15 + 8 = 2ãšããŠãªã€ã©ãŒã®å ¬åŒãæºãã, åé€åŸ : n = 9, m = 14, f = 7ã§ãã, 9â 14 + 7 = 2ãšããŠãªã€ã©ãŒã®å ¬åŒã¯æºãããã.
ã®ããã«å€ããã, 調ã¹ããš (äŸãã°, å³ 8.143ãåç §)â§âªâšâªâ©
n â n
m â mâ 1f â f â 1
ã®ããã«å€åãããã, m â 1 æ¬ã®èŸºã«å¯Ÿã㊠(8.220) ãæç«, ããªãã¡, äžã®ç¢å°ã®å³åŽã®éã«å¯ŸããŠ(8.220)ãæãç«ã€ããã§ãããã
nâ (mâ 1) + f â 1 = 2
ãã㯠140ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãæç«ãã¹ãã§ãã, ãã®åŒãå€åœ¢ãããš
nâm+ f = 2
ãšãªã, å€æ°mã®ãšãã®é¢ä¿åŒãå°ãã, ãã®æç«ãèšããããšã«ãªã. (蚌æçµãã).
ãŸãã¯ãã®å ¬åŒã«æ £ãããã, 次ã«æããäŸé¡ãèããŠã¿ãã.ï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 8.1ãªã€ã©ãŒã®å ¬åŒãçšããŠ, 次ã®ã°ã©ããå¹³é¢çã§ãããã©ããå€å¥ãã.
(1)å®å šã°ã©ãK4
(2)å®å šã°ã©ãK5
(3)å®å šäºéšã°ã©ã K3,3
(解çäŸ)ãã®ãªã€ã©ãŒã®å ¬åŒããã€ã¬ã¯ãã«çšããã«, 䜿ããããããã«æžãæããããšããå§ããã.ãªã€ã©ãŒã®å ¬åŒã®äžã«ã¯é¢æ° f ãå ¥ã£ãŠããã, ãã® f ã¯èããã°ã©ã Gã«å圢ã§ããã°ã©ãã®äžã§,
ã©ã®ã°ã©ããæ¡çšãããã«ãã£ãŠææ§æ§ããã. ã€ãŸã, é¢ã®æ°ã¯å圢ååã«ããå€åãã. äžæ¹, ç¹, 蟺ã®æ°ã¯äžå€ã§ãã. åŸã£ãŠ, ã§ããããšãªãã°, ãã®é¢æ°ãä»ã®éã§çœ®ãæããŠè©äŸ¡ããã. ãã®ç®çã®ããã«, ãŸã, ã°ã©ã Gã«é¢ããŠããã€ãã®å®çŸ©ãããŠãã.
å åš Îº : ã°ã©ã Gã®æçã®éè·¯é·.d(F ) : ã°ã©ã Gã«ãããé¢ F ã«å«ãŸããç¹ã®æ¬¡æ°å.
ãããã®å®çŸ©ã®ããšã§, ã°ã©ã Gã®ä»»æé¢ F ã«å¯ŸããŠ, 次ã®äžçåŒãæãç«ã€.
κ †d(F ) (8.221)
äŸãã°, å®å šã°ã©ã K4 ã®æç»ãšããŠã¯å³ 8.144ã«èŒãã 2éãã®ã©ã¡ããæ£ããã (ãã¡ãã, å¹³é¢çãªã®ã¯å³åŽ), å åš Îºã¯ã©ã¡ãã κ = 3ã§ãã. åŸã£ãŠ, çŽã¡ã«
K 4
å³ 8.144: å®å šã°ã©ã K4 ã®äºã€ã®æç»æ³.
κf â€â
FâF (G)
d(F ) = 2m (8.222)
ãæç«ãã. ããã§, F (G) ã¯ã°ã©ãGã«å«ãŸããé¢ã®éåã§ãã, äžã®é¢ä¿åŒã®æåŸã®çåŒã§ã¯ååºã®æ¡æè£é¡ãçšãã. ãã®åŒãšãªã€ã©ãŒã®å ¬åŒããé¢æ° f ãæ¶å»ãããš
κ(2â n+m) †2m (8.223)
ãã㯠141ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ã€ãŸã, ã°ã©ãGãå¹³é¢çãšãªãããã«ã¯, 蟺æ°mãäžããæŒãããã㊠(蟺æ°ãå€ããªããš, 蟺ãšèŸºã亀差ããå¯èœæ§ã倧ãããªãã®ã§, å¹³é¢ã°ã©ãã®èŸºæ°ã«äžéãããã®ã¯èªç¶ã§ãã)
m †κ(nâ 2)κâ 2
(8.224)
ãªãäžçåŒãæºãããªããã°ãªããªã. 以äžã§ã¯ãã®äžçåŒããã£ãŠ, äžããããã°ã©ãã«é¢ããå¹³é¢æ§ã®å€å¥åŒãšããã.
(1)å®å šã°ã©ã K4 :
ãã®ã°ã©ãã«ãããŠ, n = 4, m = 4C2 = 6, κ = 3ã§ãããã, å€å¥åŒ (8.223)ã¯
6 †3 · (4â 2)3â 2
= 6 (8.225)
ãšãªãæç«ãã. åŸã£ãŠ, å®å šã°ã©ã K4ã¯å¹³é¢çã§ãã.
(2)å®å šã°ã©ã K5 :
ãã®ã°ã©ãã«ãããŠã¯, n = 5, m = 5C2 = 10, κ = 3ã§ãããã, å€å¥åŒ (8.223)ã¯
10 †3 · (5â 2)3â 2
= 9 (8.226)
ãšãªã, äžæç«. åŸã£ãŠ, å®å šã°ã©ã K5ã¯å¹³é¢çã§ã¯ãªã.
(3)å®å šäºéšã°ã©ã K3,3 :
ãã®ã°ã©ãã«é¢ããŠã¯, n = 6, m = 32 = 9, κ = 4ã§ãããã, å€å¥åŒ (8.223)ã¯
9 †4 · (6â 2)4â 2
= 8 (8.227)
ãšãªã, äžæç«. åŸã£ãŠ, å®å šäºéšã°ã©ã K3,3 ã¯å¹³é¢çã§ã¯ãªã.
以äžã¯ã°ã©ãGãé£çµã°ã©ãã§ããå Žåã®è°è«ã§ãã£ã. ããã, ã°ã©ãGãéé£çµã§ãã, kåã®æåãæã€å Žå, ãªã€ã©ãŒã®å ¬åŒãã©ã®ããã«ä¿®æ£ãããã®ããèŠãããšã¯å®çšçã«ãæ矩深ã.
ç³» 13.3
å¹³é¢ã°ã©ã Gã«ã¯, nåã®ç¹, mæ¬ã®èŸº, f åã®é¢, kåã®æåããããšã
nâm+ f = k + 1 (8.228)
ã§ãã.
(蚌æ)
ã°ã©ãGã« kåã®æåãããå Žåã«ã¯, ç¡éé¢ã k â 1åã ãäœåã«åå®ããã®ã§, é¢æ°ã¯ f â (k â 1)ã§ãã, ããã«ã€ããŠãªã€ã©ãŒã®å ¬åŒãæžãåºããŠã¿ããš
nâm+ {f â (k â 1)} = 2 (8.229)
ãã㯠142ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãšãªã, ãããæŽçãããš
nâm+ f = k + 1 (8.230)
ãšãªã, ææã®é¢ä¿åŒãåŸããã. (蚌æçµãã).
ç³» 13.4
(1)é£çµåçŽå¹³é¢ã°ã©ã Gã, n(⥠3)åã®ç¹ãšmæ¬ã®èŸºãæã€ãšã
m †3nâ 6 (8.231)
ãæãç«ã€.(2)ããã«, Gã«äžè§åœ¢ãç¡ããã°
m †2nâ 4 (8.232)
ãæç«ãã.
(蚌æ)
(1)ã°ã©ãGã«å«ãŸããæå°ãªé¢ã¯, 3ç¹ãããªãéè·¯, ããªãã¡, äžè§åœ¢ã§ãããã
3 †d(F ) (8.233)
ãæãç«ã€. åŸã£ãŠ, æ¡æè£é¡ã«ããçŽã¡ã«
3f â€â
FâF (G)
d(F ) = 2m (8.234)
ãšãªã, ãããšãªã€ã©ãŒã®å ¬åŒ : f = 2â n+mãã, é¢æ° f ãæ¶å»ãããšææã®äžçåŒ :
m †3nâ 6 (8.235)
ãåŸããã.
(2)æããã«äžè§åœ¢ãç¡ãå Žåã«ã¯, Gã«å«ãŸããæå°ã®é¢ã¯ 4ç¹ãããªãéè·¯ã§ãã, äžçåŒ
4 †d(F ) (8.236)
ãæãç«ã€. åŸã£ãŠ, æ¡æè£é¡ããçŽã¡ã«
4f â€â
FâF (G)
d(F ) = 2m (8.237)
ãåŸãã, ãããšãªã€ã©ãŒã®å ¬åŒããé¢æ° f ãæ¶å»ããããšã«ãã, ææã®äžçåŒ
m †2nâ 4 (8.238)
ãåŸããã.
(蚌æçµãã).
ç³» 13.6å šãŠã®åçŽå¹³é¢ã°ã©ãã«ã¯æ¬¡æ° 5以äžã®ç¹ããã.
ãã㯠143ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
(蚌æ)ã°ã©ã Gã®ä»»æã®é ç¹ vã«å¯ŸããŠ
Ύ †deg(v) (8.239)
ãšãããš, æ¡æè£é¡ãšç³» 13.4(1)ãã
ÎŽn â€â
vâV (G)
deg(v) = 2m †2(3nâ 6) = 6nâ 12 (8.240)
ããªãã¡
ÎŽ †6â 12n
(8.241)
ãæãç«ã¡, åŸã£ãŠ, æ¬¡æ° ÎŽã«å¯ŸããŠ
Ύ †5 (8.242)
ãæç«ãã. (蚌æçµãã)16 .
8.1.2 亀差æ°ãšåã
ã°ã©ãã 2次å å¹³é¢å ã«åã蟌ãå Žå, ãã®ã°ã©ãããªã€ã©ãŒã®å ¬åŒããåã蟌ã¿äžå¯èœã§ãããšããã£ããšããŠã, ã©ã®çšåºŠ, åã蟌ãããšãå°é£ã§ããã®ã, ãå®éçã«æž¬ãææšãå¿ èŠãšãªã. ããã§, ããã§ã¯äº€å·®æ°ãšåããšãã 2ã€ã®ææšã«ã€ããŠèª¬æãã.
äº€å·®æ° (crossing number) cr(G) : ã°ã©ãGãå¹³é¢æåããéã«çãã, 蟺ã®æå°äº€å·®ã®æ°.åã (thickness) t(G) : ããã€ãã®å¹³é¢ã°ã©ããéãåãããŠã°ã©ãGãäœããšãã«å¿ èŠãªå¹³é¢ã°ã©ãã®æ°.ï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 8.2 ã (2003幎床 æ å ±å·¥åŠæŒç¿ II(B) #2)
rãš sãå¶æ°ã®ãšã
cr(Kr,s) †116rs(r â 2)(sâ 2)
ã瀺ã.
(解çäŸ)
å³ 8.145 (å·Š)ã®ããã«é», çœäžžãé 眮ã, é»äžžãšçœäžžãçµãã§ã§ããç·åã®äº€å·®ç¹ãåå®ããã°ãã. ãã®ãããªé 眮ã®ä»æ¹ã«ãã亀差æ°ã¯æããã«å³ 8.145(å³) ã®ãããªå Žåãããå°ãªã.ããŠ, 察称æ§ãã, å³ 8.145(å·Š) ã®ç¬¬ 3 象éã ããèããã°ãã. Y 軞äžã®ç¹ãåç¹ããè¿ãé ã«
v1, v2, · · · , vs/2 ãšã, X 軞äžã®ç¹ãåç¹ããè¿ãé ã« w1, w2, · · · , wr/2 ãšååãä»ããããšã«ãã. ãããš, vs/2ãš w1, w2, · · · , wr/2 ãçµã¶ç·åãš, vs/2â1 ãš w1, w2, · · · , wr/2 ãçµã¶ç·åã®äº€ç¹ã®æ° q1ã¯
q1 =( r
2â 1
)+( r
2â 2
)+ · · ·+
(r2â( r
2â 2
))+ 1 (8.243)
16 ãã®ç³»ã§ã®çµè«ã¯åŸã«åŠã¶ãã°ã©ãã®åœ©è²ãã®ç¯ã®å®ç 17.2 ã®èšŒæã§çšããããšã«ãªããŸã.
ãã㯠144ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
w w w
v
v
v
s/2
s/2-1
s/2-2
r/2 r/2-1 r/2-2
s/2-1
r/2-1
Y
X
å³ 8.145: ç·åã®äº€ç¹ã®åæ°ãæ°ãã (å·Š). å³å³ã¯ r = s = 4 ã®å Žåã®é 眮ã®äžäŸ.
ã§ãã. åæ§ã«ã㊠vs/2ãšw1, w2, · · · , wr/2 ãçµã¶ç·ååã³ vs/2â1ãšw1, w2, · · · , wr/2ãçµã¶ç·åãš vs/2â2
ãš w1, w2, · · · , wr/2 ãšãçµã¶ç·åã®äº€ç¹ã®æ° q2 ã¯
q2 = 2(r
2â 1
)+ 2
(r2â 2
)+ · · ·+ 2
(r2â( r
2â 2
))+ 2 (8.244)
ãšãªã. åæ§ã®å®çŸ©ã§ q3ã¯
q3 = 3(r
2â 1
)+ 3
(r2â 2
)+ · · ·+ 3
(r2â( r
2â 2
))+ 3 (8.245)
ãšãªã, v1 ãšå šãŠã®ç·åã®äº€ç¹ã®åæ° qs/2â1 ã¯
qs/2â1 =(s
2â 1
)(r2â 1
)+(s
2â 1
)( r2â 2
)+ · · ·+
(s2â 1
)(r2â( r
2â 2
))+(s
2â 1
)(8.246)
ã§ãã.åŸã£ãŠ, 第 3象éå ã«çŸãã亀ç¹ã®åæ° Qã¯
Q = q1 + q2 + · · ·+ qs/2â1
=(r
2â 1
)+(r
2â 2
)+ · · ·+
( r2â(r
2â 2
))+ 1
+ 2(r
2â 1
)+ 2
(r2â 2
)+ · · ·+ 2
(r2â(r
2â 2
))+ 2
+ 3(r
2â 1
)+ 3
(r2â 2
)+ · · ·+ 3
(r2â(r
2â 2
))+ 3
+ · · ·+ · · ·+
(s2â 1
)( r2â 1
)+(s
2â 1
)(r2â 2
)+ · · ·+
(s2â 1
)( r2â(r
2â 2
))+(s
2â 1
)â¡ p1 + p2 + · · ·+ ps/2â1 (8.247)
ãšãªã.ããã§
p1 â¡( r
2â 1
)+ 2
(r2â 1
)+ · · ·+
(s2â 1
)( r2â 1
)
=( r
2â 1
) s/2â1âk=1
k =( r
2â 1
) 12s
2
(s2â 1
)=s
4
(r2â 1
)(s2â 1
)(8.248)
ãã㯠145ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
p2 â¡(r
2â 2
)+ 2
(r2â 2
)+ · · ·+
(s2â 1
)(r2â 2
)=
( r2â 2
) s/2â1âk=1
k =s
4
(r2â 2
)(s2â 1
)(8.249)
ãããŠ
ps/2â1 =s/2â1âk=1
k =s
4
(s2â 1
)(8.250)
ã§ãã. åŸã£ãŠ Qã¯
Q = p1 + p2 + · · ·+ ps/2â1
=s
4
(s2â 1
)( r2â 1
)+s
4
(s2â 1
)(r2â 2
)+ · · ·+ s
4
(s2â 1
){r2â( r
2â 2
)}+s
4
(s2â 1
)
=s
4
(s2â 1
) r/2â1âk=1
(r2â k
)
=s
4
(s2â 1
) r2
r/2â1âk=1
âs4
(s2â 1
) r/2â1âk=1
k
=s
4
(s2â 1
) r2
( r2â 1
)â s
4
(s2â 1
) r2
( r2â 1
) 12
=sr
8
(s2â 1
)( r2â 1
){1â 1
2
}=sr
16
(s2â 1
)(r2â 1
)=
sr
16 · 4(sâ 2)(r â 2) (8.251)
ãã£ãŠ, çµå±, 第 1ïœç¬¬ 4象éã«çŸãã亀ç¹ã®ç·æ° Qtotal ã¯
Qtotal = 4ÃQ =sr
16(sâ 2)(r â 2) (8.252)
ãšãªã. ããããäº€å·®æ° Kr,s ã®äžéã
cr(Kr,s) †116rs(r â 2)(sâ 2) (8.253)
ã§äžãããã. ã€ãŸã, Kr,s ãå¹³é¢ã«æãããšãã®äº€å·®æ°ã®æå°å€ã¯ rs(r â 2)(s â 2)/16ãè¶ ããããšã¯ãªã.ï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 8.3
åçŽã°ã©ãGã« n(⥠3)åã®ç¹, åã³, mæ¬ã®èŸºããããšã, Gã®åã t(G)ã¯äžçåŒ :
t(G) â¥â
m
3nâ 6
â(8.254)
t(G) â¥âm+ 3nâ 7
3nâ 6
â(8.255)
ãæºããããšã瀺ãa .a ï¿œxï¿œ 㯠x 以äžã®æå°ã®æŽæ°. ï¿œxï¿œ 㯠x 以äžã®æ倧ã®æŽæ°ãè¡šã.
(解çäŸ)åãã¯æŽæ°ã§ãªããã°ãªããªãããšãš, ç³» 13.4 (1)ãã
t(G) â¥â
蟺ã®ç·æ°å¹³é¢ã°ã©ããšãªãããã®èŸºã®äžé
â=
âm
3nâ 6
â(8.256)
ãæãç«ã€.
ãã㯠146ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
äžæ¹, ãã®çµæãšæ£ã®æŽæ° a, bã«å¯ŸããŠæãç«ã€é¢ä¿åŒ :âa
b
â=
â(a+ bâ 1)
b
â(8.257)
ãçšããããšã«ãã, a = m, b = 3nâ 6ãšããŠçŽã¡ã« (8.255)ã®æç«ãèšãã.
â» åè : ï¿œa/bï¿œ = ï¿œ(a+ bâ 1)/bï¿œ ã®èšŒæã«é¢ããŠï¿œ
ᅵ
ᅵ
ᅵ
ãæ£ã®å®æ° a, bã«é¢ããçåŒ :
âab
â=
â(a+ bâ 1)
b
â(8.258)
ã®èšŒæ.
(a/b)ãæŽæ°ã®å Žåãšããã§ãªãå Žåã«åããŠèšŒæãã.
(i) (a/b)ãæŽæ°ã®ãšã
a/b = M ã§ãããšã
(äžåŒã®å·ŠèŸº) =a
b= M (8.259)
ã§ãã. ãŸã,
(äžåŒã®å³èŸº) =â
(a+ bâ 1)b
â=
âa
b+ 1â 1
b
â=âa
bâ 1b
â+ 1 =
âM â 1
b
â+ 1 = M (8.260)
ã§ãããã, (i)ã®ãšãé¢ä¿åŒã¯æç«.
(ii) (a/b)ãæŽæ°ã§ãªããšãa/bã®æŽæ°éšåã C, å°æ°éšåãDãšããã°
(äžåŒã®å·ŠèŸº) =âab
â= C + 1 (8.261)
ã§ãã. ãŸã
(äžåŒã®å³èŸº) =â
(a+ bâ 1)b
â=
âa
b+ 1â 1
b
â=âa
bâ 1b
â+ 1 =
âC +D â 1
b
â+ 1 (8.262)
ã§ããã, D㯠a/bã®å°æ°éšåã§ãããã
D =aâ bCb
(8.263)
ã§ãã, a, b, C ã¯æŽæ°ãªã®ã§, aâ bC ãæŽæ°ã§ãã, a > bC ãã
aâ bC †1 (8.264)
ã§ãã. åŸã£ãŠ
D >1b
(8.265)
ãªã®ã§, D â (1/b) = ε (0 †ε < 1) ãšãããš
(äžåŒã®å³èŸº) = ï¿œC + εᅵ+ 1 = C + 1 (8.266)
ãã㯠147ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãšãªã, (ii)ã®å Žåãé¢ä¿åŒãæãç«ã€. åŸã£ãŠ
âab
â=
â(a+ bâ 1)
b
â(8.267)
ã瀺ãã. (蚌æçµãã)
ᅵ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 8.4ã (2003幎床 ã¬ããŒãèª²é¡ #6 åé¡ 1 )
(1)å®å šã°ã©ãKn ã®åã t(Kn)ã¯æ¬¡äžçåŒãæºããããšã瀺ã.
t(Kn) â¥â
16(n+ 7)
â(8.268)
(2)å®å šäºéšã°ã©ã Kr,s ã®åã t(Kr,s)ã次äžçåŒãæºããããšã瀺ã.
t(Kr,s) â¥â
rs
2(r + s)â 4
â(8.269)
(解çäŸ)
(1)å®å šã°ã©ã Kn ã®èŸºã®æ°ã¯ n(nâ 1)/2ã§ãããã, äžçåŒ :
t(G) â¥âm+ 3nâ 7
3nâ 6
â(8.270)
ã«ä»£å ¥ããŠ
t(Kn) â¥â n(nâ1)
2 + 3nâ 73nâ 6
â=
ân2 + 5nâ 14
2(3nâ 6)
â=
ân+ 7
6
â(8.271)
ãšãªã, é¡æã®äžçåŒã¯æºããããããšãããã.
(2) Kr,sã«ãããŠã¯, Aã°ã«ãŒãã®ç¹ã rå, Bã°ã«ãŒãã®ç¹ã såã§, Aã°ã«ãŒãã®ããããã®ç¹ã Bã°ã«ãŒãã®ããããã®ç¹ãšçµã°ããã®ã§, 蟺ã®æ°måã³ç¹ã®æ° nã¯
m = rs (8.272)
n = r + s (8.273)
ã§äžãããã. ãŸã, Kr,sã«ã¯äžè§åœ¢ãå«ãŸããªãã®ã§, Kr,sã®èŸºã®æ°ã®äžéã¯
m †2nâ 4 â¡ m0 (8.274)
ã§äžãããã. åŸã£ãŠ, å®å šäºéšã°ã©ã Kr,sã®åã t(Kr,s)ã¯
t(Kr,s) â¥âm
m0
â=
âm
2nâ 4
â=
ârs
2(r + s)â 4
â(8.275)
ãšãªã, 確ãã«é¡æã®äžçåŒãæºãããŠãã.
ãã㯠148ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäžï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 8.5 ã (2004幎床 æŒç¿åé¡ 8 )
1. éè·¯è¡ååŒæ³ãçšããŠå®å šã°ã©ã K4ã®å šåæšã®ç·æ° Ï(K4)ãæ±ãã.2. ãªã€ã©ãŒã®å ¬åŒãçšããŠããŒã¿ãŒãœã³ã»ã°ã©ãã¯å¹³é¢æåå¯èœãã©ãããå€å®ãã.
3. è¬çŸ©äžã«èŠãç³» 13.4ãåèã«ããŠä»¥äžã®åãã«çãã.(1)é£çµã°ã©ã Gã«äžè§åœ¢, åè§åœ¢, åã³, äºè§åœ¢ãç¡ãå Žå, ã°ã©ã G ãå¹³é¢çãšãªãããã«èŸºæ°mãæºããã¹ãäžçåŒãæ±ãã.
(2) (1)ã®è°è«ãäžè¬åã, ã°ã©ãGã«K è§åœ¢ãŸã§ç¡ãå Žå, ã°ã©ãGãå¹³é¢çãšãªãããã«èŸºæ°mãæºããã¹ãäžçåŒãæ±ãã.
(3) (2)ã®çµæã§K â âã®æ¥µéããšã£ãå Žåã«èŸºæ°mã®æºããã¹ãäžçåŒãæ±ã,ãã®çµæãäœãæå³ããã®ããç°¡åã«èª¬æãã.
(解çäŸ)
1. å³ 8.146(å·Š)ã®ããã« 3ã€ã®éè·¯ã c1 = 1231, c2 = 1241, c3 = 1341 ãšå®ãã. ãããš, éè·¯è¡åRã¯
1
2
3 4
c1 c2
c3
2
3 4
1
å³ 8.146: å®å šã°ã©ã K4 ãšãã®åºæ¬éè·¯ c1, c2, c3(å·Š). å³å³ã¯å®å šã°ã©ã K4 ã®å šåæš.
R =
âââ
3 1 â11 3 1â1 1 3
âââ (8.276)
ãšããŠäžãããã.
ãšããã§, å³ã®ããã«éè·¯ãéžãã ãšã, äžçªå€åŽã® 234ãªãäžè§åœ¢ã 4çªç®ã®éè·¯ãšããŠéžãã§ã¯ãããªãã®ã, ãããã¯, éè·¯ã®éžã³æ¹ã«ä»»ææ§ãããå Žåã«ã¯ã©ãããã®ã, ãåé¡ã«ãªãã®ã ã, ãã®éã¯åºæ¬éè·¯ãéžã¶ããšã«ãã. åºæ¬éè·¯ãšã¯äŸãã°å³ 8.146(å³) ã®ãããªå®å šã°ã©ã K4ã®å šåæšã«
察ã, ããã« 1ã€ãã€èŸºãä»å ããŠã§ããéè·¯ã®ããšã§ãã. å³ 8.146(å³)ã®å šåæšã«èŸº 23ãä»å ã
ããšéè·¯ãäžã€ã§ã, ããã c1 ã§ãã. ãŸã, 蟺 24ãä»å ããã°éè·¯ c2 ã, 蟺 34ãä»å ããã°éè·¯
c3ãã§ããããšã«ãªã, ãããã¯å šãŠåºæ¬éè·¯ã§ãã. éè·¯è¡åæ³ãçšãããšãã«ã¯åºæ¬éè·¯ãéžã¹ã°ååã§ãã. ãã®é, äžè¿°ã®ããã«äžçªå€åŽã®äžè§åœ¢ã 4çªç®ã®éè·¯ãšããŠã«ãŠã³ãããŠãããã, çµæãšããŠåŸãããå šåæšã®ç·æ°ã¯åãã«ãªã (åèªãå®éã«äœå åå±éãçšããŠç¢ºãããŠã¿ãããš).ããŠ, ãã®ããã«ããŠå®çŸ©ãããåºæ¬éè·¯ã«å¯Ÿã, éè·¯è¡å (8.276) ãäœãã°, å®å šã°ã©ã K4ã®å šåæš
ã®ç·æ° Ï(K4)ã¯
Ï(K4) = |R| =
â£â£â£â£â£â£â£3 1 â11 3 1â1 1 3
â£â£â£â£â£â£â£ = 3
â£â£â£â£â£ 3 11 3
â£â£â£â£â£ââ£â£â£â£â£ 1 â1
1 3
â£â£â£â£â£ââ£â£â£â£â£ 1 â1
3 1
â£â£â£â£â£ = 16 (8.277)
ãã㯠149ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãšãªã, èš 16åã®å šåæšãååšããããšãããã.
2. ããŒã¿ãŒãœã³ã»ã°ã©ãã®å Žåã«ã¯,ç¹æ° n, 蟺æ°m, åã³å åšã®é·ã κã¯ãããã n = 10, m = 15, κ = 5ã§ãããã, ããããå€å¥åŒ :
m †κ(nâ 2)κâ 2
(8.278)
ã«ä»£å ¥ã,
15 †5 · (10â 2)5â 2
=403
= 13.3.... (8.279)
ãšãªãã®ã§äžæç«. åŸã£ãŠ, ããŒã¿ãŒãœã³ã»ã°ã©ãã¯å¹³é¢çã§ã¯ãªããšçµè«ã€ãããã.
3.
(1)äžè§åœ¢, åè§åœ¢, åã³äºè§åœ¢ãç¡ããªãã° d(F )ã¯
6 †d(F ) (8.280)
ãæºãã. åŸã£ãŠ, ãã®äžçåŒã¯æ¡æè£é¡ã«ãã
6f â€â
FâF (G)
d(F ) = 2m (8.281)
ãšæžãçŽãããšãã§ãããã, ãããšãªã€ã©ãŒã®å ¬åŒ : f = 2â n+mãã, é¢æ° f ãæ¶å»ã, 蟺æ°mã«ã€ããŠã®äžçåŒ :
m †32(nâ 2) (8.282)
ãæãç«ã€.
(2)äžè¬ã«K è§åœ¢ãŸã§ç¡ãå Žå, d(F )ã¯
K + 1 †d(F ) (8.283)
ãæºãã. åŸã£ãŠ, æ¡æè£é¡ãã
(K + 1)f â€â
FâF (G)
d(F ) = 2m (8.284)
ãšæžãçŽããã®ã§, ãããšãªã€ã©ãŒã®å ¬åŒ f = 2â n+mãã f ãæ¶å»ã, mã«é¢ããäžçåŒ :
m â€(K + 1K â 1
)(nâ 2) (8.285)
ãæãç«ã€.
(3) (2)ã®çµæã§, K ââã®æ¥µéããšã. ããã, å¿ ãK †nã§ãããã, ãã®å Žåã«ã¯K = nãšãã
æ¡ä»¶äžã§ n,K ââã®æ¥µéãèããªããã°ãªããªãç¹ã«æ³šæãã. ãããšæ¬¡ã®äžçåŒãåŸããã.
m â€(n+ 1nâ 1
)(nâ 2) = nâ 2 + 2
{1 +
1nâ 1
}= n (nââ) (8.286)
ãã㯠150ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ã€ãŸã, K(â)è§åœ¢ãŸã§ç¡ããšããããšã¯, ã°ã©ã G㯠nè§åœ¢ (ãã ã nãç¡é倧ãªã®ã§, ããã°ãç¡éè§åœ¢ã)1åãããªãã°ã©ãã§ãã.
ã¡ãªã¿ã«, nãæéã®ãŸãŸ (8.285)ã®å³èŸºã§K ââã®æ¥µéããšã£ãŠããŸããšm †nâ 2ãªãäžçåŒãåŸãããã, éè·¯ãå šãç¡ããæšãã®å Žåã®èŸºæ°ã nâ 1ã§ããããšãèãããš (ããæå³ã§ãç¡éè§åœ¢ããŸã§ç¡ãç¶æ³ã ãšèšãã), nâ 1 †nâ 2ãšãªã (ãã¡ããççŸ), ãã®å Žå, ãäžã€ã ãæåãæ〠nç¹ãããªãã°ã©ãããšããŠã¯æãããããªããªã£ãŠããŸã. åŸã£ãŠ, 極éããšãéã«ã¯K = nã®æ¡ä»¶ã®äžã§ nãç¡é倧ã«é£ã°ãå¿ èŠãããããã§ãã.⻠泚: K = nãšãã㊠nââ ã®æ¥µéããšããã«, nãæéã®ãŸãŸK ââãèããŠãããŸããããªã. ãã¡ãã, ããã¯å¿ ãæºããããŠããªããã°ãªããªãæ¡ä»¶K †nãæºãããŠããªãã®ã§ãã, ãã®å Žåã«åŸãããm †nâ 2ãšãªã€ã©ãŒã®å ¬åŒãçµãã§é¢æ° f ã«é¢ããäžçåŒãäœãã° f †0ãåŸããã. é¢æ°ã®æå°å€ã¯ã°ã©ããæšã§ããå Žåã® f = 1ãªã®ã§, ããã¯äžé©åã§ãã. æ£ããäžçåŒm †nãšãªã€ã©ãŒã®å ¬åŒãçµã㧠f ã«é¢ããäžçåŒãäœãã° f †2ãåŸããã. ãã㯠f = 2 (K(â)è§åœ¢ã®å éšã®é¢ãšå€éšã®ç¡éé¢), f = 1ïŒæš)ã®å Žåã«ããããã察å¿ããŠããããšã«ãªã (å³ 8.147åç §).
f1
f2
f1
å³ 8.147: f †2 ãæå³ããå 容ã¯, K(â)è§åœ¢ã®å éš (f1) ãšå€éš (f2) ã®èš f = 2 é¢ (å·Šå³), æšã®ç¡éé¢ (f1) ã®èš f = 1 é¢ (å³å³).
ᅵ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 8.6 ã (2005幎床 æŒç¿åé¡ 8 )
ãå¹³é¢ã°ã©ã (å°å³)ã«ãããŠã¯é£ãåã 5ã€ä»¥äžã®é£æ¥é¢ (é£æ¥åœ)ãããããªãé¢ (åœ)ãååšãã (*)ããšããåœé¡ã蚌æããããšãèããã.
(1)èããã°ã©ãã®ç¹æ°ã n, 蟺æ°ãmãšãããš
n †23m
ãæãç«ã€ããšã瀺ã.
(2) (*)ã®é : ãã©ã®é¢ (åœ)ãå°ãªããšã 6ã€ã®é£æ¥é¢ (åœ)ã«å²ãŸããŠãã (**)ããšããä»®å®ã®äžã§ã¯, èããã°ã©ãã®é¢æ°ã f ãšãããš
f †13m
ã§ãªããã°ãªããªãããšã瀺ã.
(3) (1)(2)ãšãªã€ã©ãŒã®å ¬åŒãã, ä»®å® (**)ã®ççŸãåŒãåºã, åœé¡ (*)ã®æç«ã瀺ã.
(解çäŸ)
ãã㯠151ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
(1)å³ 8.148ã®ããã«, å°å³ã§ã¯ä»»æã®ç¹ vã«æ¥ç¶ãã蟺㯠3ã€ä»¥äžã§ãã. åŸã£ãŠ, ã°ã©ãGã«ã¯ç¹ã n
v
å³ 8.148: å°å³ã§ã¯ä»»æã®ç¹ã«æ¥ç¶ãã蟺㯠3 以äžã§ãã.
åããã®ã§, 蟺æ°ã¯m ⥠3nãšãªãããã§ããã, ããã, 蟺ã®äž¡ç«¯ã«ã¯å¿ ãç¹ã 2ã€ããã®ã§, ããã§ã¯æ°ãããã§ãã, æ£ããã¯m ⥠3n/2, ã€ãŸã
n †2m3
(8.287)
ãæãç«ã€.
(2)ä»®å®ãã, äžã€ã®é¢ F ã¯å°ãªããšã 6æ¬ã®å¢çç·ã§å²ãŸããŠããã®ã§ (å³ 8.149åç §), ã°ã©ã G ã®äž
f1
f2
f3
f4
f5
f6
F
å³ 8.149: äžã€ã®é¢ F ã¯å°ãªããšã 6 æ¬ã®å¢çç·ã§å²ãŸããŠãã.
ã«é¢ã f é¢ããã°, m ⥠6f . ããã, ããã¯æ°ãããã§ãã, ä»»æã®å¢çç·ã®äž¡åŽã«ã¯å¿ ã 2ã€ã®é¢ãããã®ã§, m ⥠6f/2 = 3f , ããªãã¡
f †m
3(8.288)
ãæãç«ã€.
(3) (1)(2) ã®çµæãšãªã€ã©ãŒã®å ¬åŒãã
2 = nâm+ f †2m3âm+
m
3= 0 (8.289)
åŸã£ãŠ, 2 †0ãšãªã£ãŠããŸãã®ã§, æããã«ççŸ. ãã£ãŠ, ä»®å®ã¯ééã£ãŠãã, ãå¹³é¢ã°ã©ãã«ãããŠã¯é£ãåã 5ã€ä»¥äžã®é£æ¥é¢ããæããªãé¢ãååšãããããšã瀺ããã.
ᅵ
ᅵ
ᅵ
ãäŸé¡ 8.7 ã (2006幎床 æŒç¿åé¡ 8 )
å šãŠã®ç¹ã®æ¬¡æ°ã 4ã§ããåçŽå¹³é¢ã°ã©ã Gã«ã¯å¿ ãäžè§åœ¢ã 8å以äžå«ãŸããããšã瀺ã.
ãã㯠152ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
(解çäŸ)
ãŸã, å šãŠã®ç¹ã®æ¬¡æ°ã 4ã§ãããã
4n =â
vâV (G)
deg(v) = 2m (8.290)
ãæãç«ã€ã¹ãã§ãã. ããã§æåŸã®çåŒã¯æ¡æè£é¡ãçšããããšã«æ³šæããã. ãã®åŒ (8.290)ãšèããã°ã©ããå¹³é¢ã°ã©ãã§ããããšãããªã€ã©ãŒã®å ¬åŒ : n = 2 +mâ f ãçšããŠç¹æ° nãæ¶å»ãããš
2m+ 8 = 4f (8.291)
ãåŸããã.ãšããã§, é¡æã§ã¯ãäžè§åœ¢ã®åæ°ãã«é¢ããæ¡ä»¶ãåé¡ã«ããŠããããã§ãããã, äžè¬ã« kè§åœ¢ã®å
æ°ã Ïk ãšã, ãã® Ïk ãçšããŠçåŒ (8.291)ã¯ã©ã®ããã«æžãçŽãããšãã§ãããã«çç®ãã. ãã®ãšã,(8.291)åŒãæžãçŽãããã«ã¯m, f ã Ïk ãçšããŠæžãçŽãå¿ èŠãããã, ãããã®éã«ã¯
f =âk=3
Ïk (8.292)
2m =âk=3
kÏk (8.293)
ãªãé¢ä¿ããã ((8.293)巊蟺ã 2mãšãªãçç±ã¯, å蟺ã®äž¡åŽã«ã¯å¿ ãé¢ã 2ã€ããããã§ãã. mã§ã¯ãªã, 2mãšãªãããšã«æ³šæ !). ããã§, ããã (8.292)(8.293)åŒã (8.291)åŒã«ä»£å ¥ããŠ, ã¯ããã®æ°é ãå®éã«æžãåºããŠã¿ãã°
3Ï3 + 4Ï4 + 5Ï5 + 6Ï6 + 7Ï7 + · · ·+ 8 = 4Ï3 + 4Ï4 + 4Ï5 + 4Ï6 + 4Ï6 + 4Ï7 + · · · (8.294)
ãæãç«ã¡,
Ï3 â (Ï5 + 2Ï6 + 3Ï7 + · · ·) = 8 (8.295)
ã€ãŸã
Ï3 â (Ï5 + 2Ï6 + 3Ï7 + · · ·)â 8 = 0 †Ï3 â 8 (8.296)
ã§ããããäžè§åœ¢ã®åæ° Ï3 㯠Ï3 ⥠8 ãæºããããšã«ãªã,ãå šãŠã®ç¹ã®æ¬¡æ°ã 4ã§ããå¹³é¢ã°ã©ãã«ã¯äžè§åœ¢ã 8å以äžååšããããšããé¡æã蚌æããã.
ãã㯠153ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäžï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 8.8ã (2004幎床æ å ±å·¥åŠæŒç¿ II(B) #1)
ã°ã©ã G (ç¹ã®æ° : n ⥠4) ãäžè§åœ¢ã®ã¿ãå«ãå¹³é¢ã°ã©ãã§ãããšãã. Gã«å«ãŸããæ¬¡æ° kã®ç¹
ã®åæ°ã nk ãšãããšã
(1) Gã®èŸºæ°mã
m = 3nâ 6
ã§äžããããããšã瀺ã.
(2)次ã®é¢ä¿åŒ :3n3 + 2n4 + n5 â n7 â 2n8 â · · · = 12
ãæãç«ã€ããšã瀺ã.
(3) Gã¯æ¬¡æ° 5以äžã®ç¹ã 4ã€ä»¥äžå«ãããšã瀺ã.
ä»åºŠã¯ã°ã©ã Gã¯å šãŠã®ç¹ã®æ¬¡æ°ã 3ã§ããå¹³é¢ã°ã©ãã§ãã, Ïk åã® k è§åœ¢ãå«ããšããã.ãã®ãšã
(4) Gã®èŸºæ°m, é¢æ° f ã®éã«ã¯
m+ 6 = 3f
ãªãé¢ä¿ãæç«ããããšã瀺ã.
(5)次ã®é¢ä¿åŒ :3Ï3 + 2Ï4 + Ï5 â Ï7 â 2Ï8 â · · · = 12
ãæãç«ã€ããšã瀺ã.
(6) Gã«ã¯ 5è§åœ¢ä»¥äžã®é¢ã 4ã€ä»¥äžå«ãŸããããšã瀺ã.
(解çäŸ)
(1)å šãŠã®èŸºã¯ 3æ¬ã®èŸºã§å²ãŸããŠãã, å šãŠã®èŸºã¯ 2ã€ã®é¢ã®å¢çãšãªã£ãŠããã®ã§, é¢æ° f , 蟺æ°mã®
éã«ã¯
3f = 2m (8.297)
ãæãç«ã€. ãããšãªã€ã©ãŒã®å ¬åŒ : nâm+ f = 2ããé¢æ° f ãæ¶å»ããã°
m = 3nâ 6 (8.298)
ãåŸããã.(2) (8.298)ã 2åãããã®ã«
n =âk=3
nk (8.299)
2m =âk=3
knk (8.300)
ãã㯠154ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãä»£å ¥ããã° âk=3
knk = 6âk=3
nk â 12 (8.301)
ãåŸãããã, åã®äžã®ã¯ããã®æ°é ãæžãåºããŠã¿ããš
3n3 + 4n4 + 5n5 + 6n6 + 7n7 + 8n8 + · · · = 6(n3 + n4 + n5 + n6 + n7 + n8 + · · ·)â 12
(8.302)
ããªãã¡
3n3 + 2n4 + n5 â n7 â 2n8 â · · · = 12 (8.303)
ãæãç«ã€.
(3) (2)ã§åŸãããé¢ä¿åŒãã
3n3 + 2n4 + n5 â n7 â 2n8 â · · · â 12 = 0 †3n3 + 2n4 + n5 â 12 (8.304)
ã§ãããã
3n3 + 2n4 + n5 ⥠12 (8.305)
ã§ãã. ãŸã, æããã« (3n3 + 3n4 + 3n5) ⥠3n3 + 2n4 + n5 ã§ãããã, ãããã®äžçåŒããçŽã¡ã«
n3 + n4 + n5 ⥠13
(3n3 + 2n4 + n5) ⥠13à 12 = 4 (8.306)
åŸã£ãŠ, ã°ã©ã Gã«ã¯æ¬¡æ°ã 5以äžã®ç¹ã 4ã€ä»¥äžå«ãŸããããšã瀺ãã.
(4)æ¡æè£é¡ãã 3n = 2mãæãç«ã€ã, ãããšãªã€ã©ãŒã®å ¬åŒãã nãæ¶å»ããŠ
6 +m = 3f (8.307)
ãæãç«ã€.
(5) (8.307)åŒã 2åãããã®ã«
f =âk=3
Ïk (8.308)
2m =âk=3
kÏk (8.309)
ãä»£å ¥ã, åã®äžã®ã¯ããã®æ°é ãæžãåºããŠã¿ããš
3Ï3 + 2Ï4 + Ï5 â Ï7 â 2Ï8 â · · · = 12 (8.310)
ãæãç«ã€ããšãããã.
(6) (3)ãšåæ§ã«ããŠ
Ï3 + Ï4 + Ï5 ⥠13
(3Ï3 + 2Ï4 + Ï5) ⥠13à 12 = 4 (8.311)
ããªãã¡, ã°ã©ã Gã«ã¯ 5è§åœ¢ä»¥äžã®é¢ã 4ã€ä»¥äžå«ãŸããããšãããã.
ãã㯠155ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ᅵ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 8.9ã (2007幎床 æŒç¿åé¡ 8 )
æ¬¡æ° kã®ç¹ã®åæ°ã nk ãšãã. æ¬¡æ° 1, ãŸã㯠2ã®ç¹ãå«ãŸãªãå¹³é¢ã°ã©ãã«å¯Ÿã
3n3 + 2n4 + n5 ⥠12 + n7 + 2n8 + 3n9 + · · ·
ãæãç«ã€ããšã瀺ã.
(解çäŸ)
æ¬¡æ° kã®ç¹ã®åæ°ã nk ãšããã°, èããŠããå¹³é¢ã°ã©ãã®äžã«ã¯ç·æ° nã®ç¹ãããã®ã ãã
âk=3
nk = n (8.312)
ãæãç«ã€. ããã§, ãã®å¹³é¢ã°ã©ãã«ã¯ãæ¬¡æ° 1ãš 2ã®ç¹ãç¡ããããã§ãããã, äžåŒå·ŠèŸºã®å㯠k = 3ããå§ãŸã£ãŠããããšã«æ³šæããã. ãŸã, ãã®å¹³é¢ã°ã©ãã®æ¬¡æ°å㯠nk ã®å®çŸ©ãã
âk=3 knk ãšæžãã
ã, æ¡æè£é¡ãæãç«ã€ããšã«æ³šæããã°
âk=3
knk = 2m (8.313)
ãªãé¢ä¿åŒãæãç«ã€. ãšããã§, å¹³é¢ã°ã©ãã®é¢ã®ãã¡, æå°ã®èŸºãæã€ãã®ã¯ãäžè§åœ¢ãã§ãã, å蟺ã®äž¡åŽã«é¢ãããããšã«æ³šæããã°, ãã®å¹³é¢ã°ã©ãã®èŸºæ°mãšé¢æ° f ã®éã«ã¯m ⥠3f/2, ã€ãŸã
3f †2m (8.314)
ãæãç«ã€. ãã®äžçåŒã®é¢æ° f ããªã€ã©ãŒã®å ¬åŒ: f = 2â n+mã«ããæ¶å»ãããš
3nâm †6 (8.315)
ãåŸãããã, ãã® nãšmã« (8.312)(8.313)åŒãããããä»£å ¥ããã°
4âk=3
nk ââk=3
knk ⥠12 (8.316)
ãšãªã. ãã®åã®äžã®åãã®æ°é ãæžãåºããŠã¿ãã°, åé¡ã«äžããããäžçåŒ:
3n3 + 2n4 + n5 ⥠12 + n7 + 2n8 + 3n9 + · · · (8.317)
ãæãç«ã€ããšãããã.
ãã㯠156ããŒãžç®
157
第9åè¬çŸ©
8.1.3 å察ã°ã©ã
ããã§ã¯æ¬¡ç¯ã®ã圩è²ããåããšã, æ§ã ãªå Žé¢ã«å¿çšãããŠããéèŠãªæŠå¿µã§ãããå察æ§ããå察ã°ã©ããã«ã€ããŠåŠã¶.
幟äœåŠçå察ã°ã©ãã®äœãæ¹ãšãã®æ§è³ª
幟äœåŠçå察ã°ã©ãã¯, äžããããå¹³é¢ã°ã©ããã, ããã«ãŒã«ã«åŸã£ãŠäœããã. ãŸã, ãã®å察ã°ã©ãã®äœãæ¹ãç¥ããªããã°ãªããªã. ããã§, ããã§ã¯ãŸã, 幟äœåŠçå察ã°ã©ãã®æãæ¹ãåŠã³, å ·äœçã«äžããããå¹³é¢ã°ã©ãã®å¹ŸäœåŠçå察ã°ã©ããæ±ããŠã¿ã. 次ãã§, äžè¬ã®ã°ã©ãã«ãããŠ, ãã®ã°ã©ããšå察ã°ã©ãã®éã«ã©ã®ãããªé¢ä¿ãæãç«ã€ã®ãã詳ããèŠãŠè¡ã.
幟äœåŠçå察ã°ã©ãã®äœãæ¹
以äžã®äœãæ¹ãå³ã«èŒããã°ã©ã Gãåèã«ããªããèŠãŠé ããã.
(1)ã°ã©ãGã®åé¢ f ã®å åŽã®ç¹ vâãéžã¶. â ããããŠæãããç¹ãå察ã°ã©ãGâã®ç¹ãšãªã.(2)ã°ã©ã Gã®å蟺 eã«å¯Ÿå¿ãããŠ, eã«ã§ããã ã亀差ããç· eâ ãæããŠ, eã«æ¥ãã 2ã€ã®é¢
f ã®ç¹ vâ ãçµã¶ããã«ãã. â ããããŠã§ãã蟺ãå察ã°ã©ãGâ ã®èŸºãšãªã.
a
b
c
d e
f1
f2
f3
f4 f5
å³ 8.150: èããå¹³é¢ã°ã©ã G ãšãã®å¹ŸäœåŠçå察 (å³ã®çœäžžãšç Žç·ãããªãã°ã©ã).
å ·äœçã«å察ã°ã©ãã®äœãæ¹ãç·Žç¿ããŠã¿ãããã«æ¬¡ã®äŸé¡ããã£ãŠã¿ãã.ᅵᅵ
ᅵᅵ
ãäŸé¡ 8.7
å®å šã°ã©ã K4ã®å察ã°ã©ãã¯, ãã¯ã, å®å šã°ã©ã K4ã§ããããšã瀺ã.
(解çäŸ)
äžã«æ瀺ãããäœãæ¹ãã«åŸã£ãŠ, å察ã°ã©ããäœã£ãŠã¿ããš, å³ 8.151ã®å³åŽã®ããã«ãªã, ããã¯å®å š
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ã°ã©ãK4ã§ãã. äžã«æ瀺ãããäœãæ¹ãã«ãã£ãŠã°ã©ã Gããäœãããšã®ã§ããå察ã°ã©ã Gâ ã®ç¹,
G G*
å³ 8.151: å®å šã°ã©ã K4 ãšãã®å¹ŸäœåŠçå察ã°ã©ã (å³).
蟺, é¢ã®æ° nâ,mâ, åã³, fâã¯ããšã®ã°ã©ãGã®ããããã®æ°ãšã©ã®ããã«é¢ä¿ããã®ã§ãããã ? ããã«é¢ããŠã¯æ¬¡ã®è£é¡ã«ãŸãšããããŠãã.
è£é¡ 15.1å¹³é¢é£çµã°ã©ã Gã«ã¯ nåã®ç¹, mæ¬ã®èŸº, f åã®é¢ããããšãã. ãã®ãšã, ãã®å¹ŸäœåŠçå察ã°ã©ã Gâ ã«ã¯ nâ åã®ç¹, mâ æ¬ã®èŸº, fâ åã®é¢ããããªãã°
nâ = f, mâ = m, fâ = n
ãæãç«ã€.
(蚌æ)
å察ã°ã©ãã®äœãæ¹ãã, ãã°ã©ãGã®åé¢ã«å察ã°ã©ãã®ç¹ãæã¡èŸŒããããšãã nâ = f ã, ãã°ã©ãGã®å蟺 eã«äº€å·®ããããã«å察ã°ã©ãã®èŸº eâãæãããšããããšããmâ = mãçŽã¡ã«èšãã.äžæ¹, å察ã°ã©ãã«ã€ããŠã®ãªã€ã©ãŒã®å ¬åŒãã
f = nâ = 2 +mâ â fâ (8.318)
ã§ãããã, ãããã°ã©ãGã«é¢ãããªã€ã©ãŒã®å ¬åŒ
nâm+ f = 2 (8.319)
ã€ãŸã, nâmâ + f = 2 ã«ä»£å ¥ããŠæŽçãããš nâmâ + 2 +mâ â fâ = 2, ããªãã¡
fâ = n (8.320)
ãåŸããã. (蚌æçµãã).
å®ç 15.2
ã°ã©ãGãé£çµå¹³é¢ãªãã°, Gââ ã¯ã°ã©ãGãšå圢ã§ãã.
ãã®å®çã«é¢é£ããæŒç¿åé¡ â äŸé¡ 9.1 åç §.
å®ç 15.3å¹³é¢ã°ã©ã Gã®å¹ŸäœåŠçå察ã Gâ ãšãã. ãã®ãšã, ã°ã©ã Gã®å蟺ã®, ããéåãã°ã©ã Gã«ãããŠéè·¯ã§ããããã®å¿ èŠååæ¡ä»¶ã¯, ããã«å¯Ÿå¿ããå察ã°ã©ãGâã®èŸºéåã, ã°ã©ãGâ
ã«ãããŠã«ããã»ããã«ãªã£ãŠããããšã§ãã.
ãã㯠158ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
(蚌æ)å¹³é¢ã°ã©ã G ã®ä»»æã®éè·¯ C ãéžã¶ãš, C ã®äžã«ã¯é¢ãäžã€ä»¥äžããã®ã§, ãã®é¢å ã«ç¹ãäžã€çœ®ã, ãããå察ã°ã©ã Gâ ã®ç¹ vâ ã«å¯Ÿå¿ããã. ãã®ç¹ vâ ãšéè·¯ C ãæ§æããå蟺ã亀差ããã
ããã«æ°ããªèŸºãåŒã, ãããå察ã°ã©ãã®èŸºã«å¯Ÿå¿ããããš, ãã®æç¶ãã«ãã£ãŠ, 亀差ãããã°ã©ã G ã«ããã蟺éå {c1c2, c2c3, c3c4, c4c5, c5c6, c6c1} ã®å ã«å¯Ÿå¿ãã幟äœåŠçå察ã°ã©ã Gâ ã®èŸºéå{vâa, vâb, vâc, vâd, vâe, vâf} ã¯, å察ã°ã©ãGâã«ãããŠã¯ã«ããã»ãããšãªã£ãŠãã (å³ 8.152åç §). ã€ãŸ
v*
G
C
f
e
d c
b
ac1
c2
c3
c4
c5
c6
å³ 8.152: ã°ã©ã G ã«å«ãŸããéè·¯ C ãš, G ã®å¹ŸäœåŠçå察ã°ã©ãã®äžéš (çœäžžãšç Žç·).
ã, ããããé€å»ãããš, Gâ 㯠vâ ãšãã以å€ã®éšåã«åé¢ãã.ãŸã, 以äžã®æç¶ãã®éããã©ãããšã«ããé¡æã¯ç€ºããã. (蚌æçµãã).
ç³» 15.4ã°ã©ã Gã®èŸºã®ããéåã Gã®ã«ããã»ããã§ããããã®å¿ èŠååæ¡ä»¶ã¯, 察å¿ãã幟äœåŠçå察ã°ã©ã Gâ ã®èŸºéåãGâ ã®éè·¯ãšãªãããšã§ãã.
蚌æãäžããåã«, å³ 8.153ã«èŒããã°ã©ãGã«å¯ŸããŠ, äžèšã®äºå®ã確ãããŠããã. ã°ã©ãGã®ãã蟺
1
2
3
4
5
67
8
9
10
11
12g
a
b
cd
e
f
G
å³ 8.153: ã°ã©ã G(é»äžžãšå®ç·) ãšãã®å¹ŸäœåŠçå察ã°ã©ã (çœäžžãšç Žç·).
éå {17, 28, 39, 410, 511, 612} ãã°ã©ã G ã®ã«ããã»ããã§ããã, ããã«å¯Ÿå¿ãã幟äœåŠçå察ã°ã©ãGâ ã®èŸºéå㯠{fa, ab, bc, cd, de, ef} ã§ãã, ãããã¯Gâã«ãããŠéè·¯ãšãªã£ãŠãã. 2ã€ã®éåã®èŠçŽ éã«ã¯ 1察 1ã®å¯Ÿå¿é¢ä¿ããã.
ãã㯠159ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
(蚌æ)å®ç 15.3 ã G â Gâ, Gâ â Gââ ãšããŠèªã¿ããããš, å®ç 15.2 ãã, ã°ã©ã G ãå¹³é¢é£çµãªãã°,Gââ âŒ= Gã§ãããã,
ãå¹³é¢ã°ã©ã Gâã®å¹ŸäœåŠçå察ãGãšãããš, Gâ ã®ããéåã Gâ ã«ãããŠéè·¯ã§ããããã®å¿ èŠååæ¡ä»¶ã¯, ããã«å¯Ÿå¿ãã Gã®èŸºéåã Gã«ãããŠã«ããã»ããã§ããããšã§ããã
ãšèšãã. åŸã£ãŠãã®ç³»ã瀺ãããšãã§ãã. (蚌æçµãã).ï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 9.1ã (2003幎床 ã¬ããŒãèª²é¡ #7 åé¡ 1 )
(1)è»èŒªã®å察ã¯è»èŒªã§ããããšã瀺ã.(2)å¹³é¢ã°ã©ãGãéé£çµãªãã°, Gââ 㯠Gã«å圢ã§ãªãããšãäŸã§ç€ºã.(3) Gãé£çµãªå¹³é¢ã°ã©ãã§ãããšã, Gã®å šåæšã¯Gâã®ããå šåæšã®è£ã°ã©ãã«å¯Ÿå¿ããããšãäŸã§ç€ºã.
(解çäŸ)
(1)ãè»èŒªWn ãšã¯, nâ 1åã®ç¹ãæã€éè·¯ Cnâ1 ã«äžã€ã®æ°ããç¹ vãå ã, vãšä»ã®å šãŠã® n â 1åã®ç¹ãã€ãªãã§ã§ããã°ã©ãã§ãããããšãæãåºã. è£é¡ 15.1 ãã nâ = f , ã€ãŸã, å察ã°ã©ãã®ç¹ã®æ°ã¯å ã ã®ã°ã©ãã®é¢æ°ã«çãã, G â¡ Cnâ1 ã®ç¡éé¢ãé€ãé¢æ°ã¯ n â 1åã§ãã, åŸã£ãŠ,nâ 1åã®ããããã®é¢ã« nâ 1åã®ç¹ãäžã€äžã€çœ®ã (ãããã Gâ ã®äžã® nâ 1åã®ç¹ã«ãªã), ããããçµã㧠Câ
nâ1 ãäœã, æåŸã«ç¡éé¢ã«äžç¹ vâ ã眮ã (ãã㧠Gâ ã®ç¹ã®ç·æ°ã¯ n), ãããš Cânâ1
ã® nâ 1åã®ç¹ãšãçžäºã«çµã¹ã° (ãããã®ç·ã Gã®å蟺ãšäžèŸºãã€äº€å·®ããããšã¯æãã) åºæ¥äžããã°ã©ãã¯Wâ
n ã§ãã, åŸã£ãŠ, ãè»èŒªã®å察ã¯è»èŒªã§ãããããšãããã. å³ 8.154ã«W7ã®å Žå
ã®äŸã瀺ãã.
å³ 8.154: W7 (å·Šå³ã®é»äžžãšå®ç·) ãšãã®å¹ŸäœåŠçå察ã°ã©ã (å·Šå³ã®çœäžžãšç Žç·åã³å³å³, ãããã¯å圢ã§ãã).
(2)ãŸã, äŸãšããŠå³ 8.155(å·Š)ã®é»äžžãšå®ç·ã§äžããããéé£çµã°ã©ãGãèãã. ãã®éé£çµãªã°ã©ãG ããã§å¹ŸäœåŠçå察ã°ã©ãGâ ãæããš, å³ 8.155(å·Š)ã®çœäžžãšç Žç·ãåŸããã. ãããGâ ã§ãã,ããã«ãã®Gâ ã®å¹ŸäœåŠçå察ã°ã©ããæããšå³ 8.155(å³)ã®é»äžžãšå®ç·ã®ã°ã©ããšãªã, æããã«ãã®ã°ã©ã㯠Gãšå圢ã§ã¯ãªãããšãããã (Gââ ã¯é£çµã°ã©ããšãªã£ãŠãã).
(3)ãŸã, å¹³é¢é£çµã°ã©ãGãå³ 8.156ã®é»äžžãšå®ç·ã®ããã«éžã¶. ããã«å¯Ÿãã幟äœåŠçå察ã°ã©ãGâ
ã¯åå³ 8.156ã®çœäžžãšç Žç·ã§äžãããã.
äžæ¹, å¹³é¢é£çµã°ã©ãGã®å šåæšã®äžã€ã¯å³ 8.156ã®å³åŽã§äžãããã. Gã®å¹ŸäœåŠçå察ã°ã©ãGâ
ãã㯠160ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
G
G G *
G **
å³ 8.155: å·Šã¯éé£çµã°ã©ã G (é»äžžãšå®ç·) ãšãã®å¹ŸäœåŠçå察ã°ã©ã Gâ ( çœäžžãšç Žç·). å³ã¯ Gâ (é»äžžãšå®ç·) ãšãã®å¹ŸäœåŠçå察ã°ã©ã Gââ ( çœäžžãšç Žç·).
å³ 8.156: é£çµå¹³é¢ã°ã©ã G (é»äžžãšå®ç·) ãšãã®å¹ŸäœåŠçå察ã°ã©ã Gâ ( çœäžžãšç Žç·). å³å³ã¯ G ã®å šåæš
ã®å šåæšãå³ 8.157ã®å·ŠåŽã®ããã«éžã¶ãš, ãã®è£ã°ã©ãã¯å 8.157ã®å³åŽã®ãããªæšãšããŠåŸãããã®ã§, ããã¯ã°ã©ã Gã®å šåæšãšçãã. åŸã£ãŠ, ãã®äŸã«é¢ããŠé¡æã瀺ãã.
å³ 8.157: 幟äœåŠçå察ã°ã©ã Gââ ã®å šåæš (å·Š) ãšãã®è£ã°ã©ã (å³).
æœè±¡çå察ãšããæŠå¿µ
æœè±¡çå察 (abstract dual) : Gã®èŸºéåãš Gâ ã®èŸºéåã®éã« 1察 1察å¿ããã, ããã, Gã®èŸºã®ããéåãGã«ãããŠéè·¯ã«ãªãã®ã¯, 察å¿ããGâã®èŸºéåãGâã«ãããŠã«ããã»ããã«ãªããšãã§ãã, ãã€, ãã®ãšãã«éãå Žå, Gâ ã Gã®æœè±¡çå察ãšåŒã¶. (泚) : Gâ ãå¹³é¢ã°ã©ã Gã®å¹ŸäœåŠçå察ãªãã°, Gâ 㯠Gã®æœè±¡çå察ã§ããã.
8.2 ã°ã©ãã®åœ©è²
ããããã¯ã°ã©ãã®åœ©è²åé¡ã«å ¥ã.
ãã㯠161ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
a
b
c
e
d
f
g
h
a*
b*
c*
e*
d*
g*
h*
f*
å³ 8.158: ã°ã©ã G ãšãã®æœè±¡çå察ã°ã©ã (å³).
g*
b*e*
h*
f*
a*
b*
d*
e*
c*
å³ 8.159: ã«ããã»ãã aâ, câ, dâ ã«ãã£ãŠã§ããã°ã©ã (å·ŠåŽ) ãšã«ããã»ãã fâ, gâ, hâ ã«ããã§ããã°ã©ã (å³åŽ).
8.2.1 ç¹åœ©è²
k-圩è²å¯èœ (k-colourable) : kåã®è²ã®äžã€ãGã®åç¹ã«å²ãåœãŠ, é£æ¥ããã©ã® 2ã€ã®ç¹ãåãè²ã«ãªããªãããã«ã§ãããšã.
k-圩è²ç (k-chromatic) : ã°ã©ã Gã k圩è²å¯èœã§ããã, (k â 1)圩è²äžå¯èœã§ãããšã.â ã°ã©ã Gã®åœ©è²æ° (chromatic number) 㯠kã§ãã. ãããŠ
Ï(G) = k
ã®ããã«è¡šèšãã. äŸãã°, å³ã«èŒããã°ã©ãGã®åœ©è²æ°ã¯ 4ã§ãã. 代衚çã°ã©ãã«é¢ãã, ããããã®
Gβ
β
γ
α α
Ï (G) = 4
å³ 8.160: ãã®ã°ã©ã G ã®åœ©è²æ°ã¯ Ï(G) = 4 ã§ãã.
ãã㯠162ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
圩è²æ°ã¯ â§âªâšâªâ©
Ï(Kn) = n
Ï(Nn) = 1Ï(Kr,s) = 2
ã®ããã«ãªã.ããã§, ç¹åœ©è²ã«å¯ŸããŠ, 幟ã€ãã®éèŠãªå®çãèŠãŠããã.
å®ç 17.1åçŽã°ã©ãGã®æ倧次æ°ãÎãªãã°, ã°ã©ãG㯠(Î + 1)-圩è²å¯èœã§ãã.
(蚌æ)
å³ 8.161ã®ããã«, ä»»æã®ç¹ våã³, v ã«æ¥ç¶ãã蟺ãé€å»ããŠã§ããã°ã©ãã«ã¯ n â 1åã®ç¹ããã, ãã®æ倧次æ°ã¯Î以äž. ããã§, ãã® nâ 1åã®ç¹ãããªãã°ã©ã㯠(Î + 1)-圩è²å¯èœã§ãããšä»®å®ãã. ã
v
G
å³ 8.161: ä»»æã®ç¹ v ãåé€ããŠã§ããã°ã©ãã®æ倧次æ°ãèãã.
ã®ãšã, vã«é£æ¥ããŠãã Îå以äžã®ç¹ãšã¯ç°ãªãè²ã§ vã圩è²ããã°, ã°ã©ã Gã® (Î + 1)-圩è²ãåŸããã. (蚌æçµãã).
å®ç 17.3
å šãŠã®åçŽå¹³é¢ã°ã©ã㯠6-圩è²å¯èœã§ãã.
(蚌æ)
ã°ã©ãG㯠n(> 6) åã®ç¹ãæã€åçŽå¹³é¢ã°ã©ãã§ãããšãã. ãããŠ, nâ 1åã®ç¹ãæã€å šãŠã®åçŽå¹³é¢ã°ã©ã㯠6-圩è²å¯èœã§ãããšãã. å®ç 13.6 : ãå šãŠã®åçŽå¹³é¢ã°ã©ãã«ã¯æ¬¡æ° 5以äžã®ç¹ãããããã, Gã«ã¯ 5次以äžã®ç¹ v ããã. å³ 8.162ã®ããã«, v ãš vã«æ¥ç¶ãã蟺ãé€å»ãããš, æ®ãã®ã°ã©ãã«
å³ 8.162: ããã§èããã°ã©ã.
㯠nâ 1åã®ç¹ãããªãã®ã§, ä»®å®ãã 6-圩è²å¯èœã§ãã. v ã«é£æ¥ããŠãã 5å以äžã®ç¹ãšã¯ç°ãªãç¹ã§
ãã㯠163ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
vã圩è²ããã°, Gã® 6-圩è²ãåŸããã. (蚌æçµãã).
å®ç 17.4
å šãŠã®åçŽå¹³é¢ã°ã©ã㯠5-圩è²å¯èœã§ãã.
(蚌æ)
n > 5ãšãã. ãnâ 1å以äžã®ç¹ãæã€å šãŠã®åçŽå¹³é¢ã°ã©ã㯠5-圩è²å¯èœã§ããããšãã. ãããåž°çŽæ³ã®ä»®å®ãšãªã. å®ç 13.6ãã, Gã«ã¯æ¬¡æ° 5以äžã®ç¹ vããã. deg(v) < 5ãªãã°èšŒæã¯çµãã. åŸã£ãŠ, 以äžã§ã¯ deg(v) = 5ã§ãããšãã.v1, · · · , v5 ã¯ãã®é ã« vã®ãŸããã«é 眮ãããŠãããšãã (å³ 8.163åç §). v1, · · · , v5 ãå šãŠé£æ¥ããŠã
v5
v1
v2
v3v4
v
v4
v5
v1(v3)
v2
v5
v4
v3
v1
v2v
å³ 8.163: ããã§èããã°ã©ã.
ãã°å®å šã°ã©ãK5ã«ãªã£ãŠããŸãã®ã§, å šãŠã¯é£æ¥ããŠããªããšãã. 2æ¬ã®èŸº vv1, vv3ãçž®çŽãããš, å¹³é¢ã°ã©ããã§ããŠ, ããã«ã¯é«ã nâ 1åããç¹ããªãã®ã§, 5-圩è²å¯èœ. 次㫠2æ¬ã®èŸºãå ã«æ»ã, vã«åœãŠãããè²ã§ v1, v3ã®äž¡æ¹ã圩è²ãã. ç¹ vã«å²ãåœãŠãããè²ãšã¯ç°ãªãè²ã§ vã圩è²ããã°Gã® 5圩è²ãåŸããã. (蚌æçµãã).
æåŸã«åœ©è²ã®å¿çšåé¡ãäžé¡, äŸé¡ãšããŠèŠãŠããã.
ãã㯠164ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäžï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 9.2 ã (2003幎床 ã¬ããŒãèª²é¡ #8 åé¡ 1 )
è¬çŸ©ã®æéå²ãäœããã. è€æ°ã®è¬çŸ©ãåãããåŠçãå± ãã®ã§, è¬çŸ©ã«ãã£ãŠã¯åãæé垯ãé¿ããªããã°ãããªã. äžè¡šã®æå° (â)ã¯åãæé垯ã«ãã£ãŠã¯ãããªãè¬çŸ©ãè¡šããŠãã.
a b c d e f g
a â â â â â â âb â â â â â â âc â â â â â â âd â â â â â â âe â â â â â â âf â â â â â â âg â â â â â â â
ãã®ãšã以äžã®åã (1)(2)ã«çãã.
(1) a, b, c, d, e, f, g ã® 7ã€ã®è¬çŸ©ãç¹ã§è¡šã, åãæé垯ã«ãã£ãŠã¯ãããªãè¬çŸ©ã«å¯Ÿå¿ãã 2
ç¹ãé£æ¥ãããããªã°ã©ããæã.
(2) (1)ã§åŸãããã°ã©ãã®åç¹ãã®ãªã·ã£æå α, β, γ, · · · ã§åœ©è²ããããšã«ãã, ãã® 7ã€ã®è¬çŸ©ã®æéå²ã«ã¯äœæéãå¿ èŠãšãªãããçãã.
(解çäŸ)
(1)åé¡æã«äžããããè¡šã«åŸã£ãŠ, æå°ã®ã€ããè¬çŸ©å士ãé£æ¥ããããã«ã°ã©ããæããšå³ 8.164 ã®ããã«ãªã.
g
a
f
c
b
d
e
(γ)
(β)
(β)(α)
(γ)
(ÎŽ)
(α)
å³ 8.164: è¬çŸ©éã®é¢ä¿ãè¡šãã°ã©ã. åæé垯ã«éè¬ãããè¬çŸ©ã¯äºãã«é£æ¥ããŠãã. æ¬åŒ§å ã¯éè¬ãã¹ãæé垯 (è²).
(2)å®éã«å³ 8.164ã«èŠãããã«, ãã®ã°ã©ããç¹åœ©è²ããããã«å¿ èŠãªè²æ°ã¯ α, β, γ, ÎŽã® 4è²ã§ããã,ããã¯æã次æ°ã®å€§ããªç¹ã bã§ãã, ãŸã, bã«é£æ¥ããŠãã 4ç¹ã®äžã§ bãé€ãä»ç¹ãšãé£æ¥ããŠ
ããç¹ã 3ç¹ (a, c, d)ã§ããããšãã, b㯠Ύã§åœ©è²ããããåŸã, ãã® ÎŽãŸã§ã®ã®ãªã·ã£æåã®æ°ã
æ±ãã圩è²æ° 4ã§ããããšããã容æã«ããã. 以äžãã
è¬çŸ© c, e㯠αè¬æã«éè¬
ãã㯠165ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
è¬çŸ© a, f 㯠β è¬æã«éè¬
è¬çŸ© d, g㯠γ è¬æã«éè¬
è¬çŸ© bã ã㯠Ύè¬æã«éè¬
ããããã«æéå²ãäœãã°è¯ãããšãããã.ï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 9.3 ã (2004幎床 æŒç¿åé¡ 9 )
1. å³ã®ã°ã©ãGã«é¢ããŠä»¥äžã®åãã«çãã.
a b
c
d e
G
(1)ã°ã©ã Gã®å¹ŸäœåŠçå察ã°ã©ãGâ ãæã.(2) (1)ã§åŸãããã°ã©ãGâã®å¹ŸäœåŠçå察ã°ã©ãGââãæã, GââãšGã®éã®å圢ååãæ±ãã.(泚) : ãå圢ããå圢ååãã«é¢ããŠã¯, è¬çŸ©ããŒã#2ã® 2.2 å圢ã®éšåãèªã¿è¿ããŠèŠãããš.
2. ã°ã©ã Gã®ç¹åœ©è²ã«é¢ããŠä»¥äžã®åãã«çãã.
(1)ã°ã©ã Gã¯äžè§åœ¢ãå«ãŸãªããšãã. ãªã€ã©ãŒã®å ¬åŒãçšããŠ, ãã®ã°ã©ã Gã«ã¯æ¬¡æ° 3以äžã®ç¹ãååšããããšã瀺ã.
(2)ã°ã©ã G㯠3è²ã§ç¹åœ©è²å¯èœã§ããããšã瀺ã.(3) (1)ã®çµæãã°ã©ã GãK è§åœ¢ãŸã§å«ãŸãªããšããå Žåã«æ¡åŒµãã.
(解çäŸ)
1.(1)ã°ã©ã Gã®å¹ŸäœåŠçå察ã°ã©ã Gâ ãå³ 8.165ã«ç€ºã.(2) (1)ã§åŸãããã°ã©ã Gâã®å¹ŸäœåŠçå察ã°ã©ãGââ ã¯å³ 8.165ã®ããã«ãªã, ãã®ã°ã©ãã®åç¹ã«ãããã 1, 2, 3, 4, 5ãšååãã€ããããšã«ãã. ãã®ãšã, åå {Ξ, Ï}ã
Ξ : V (G) â V (Gââ)
Ï : E(G) â E(Gââ)
ã®ããã«å®çŸ©ãããš, Ξ(a) = 1, Ξ(b) = 2, Ξ(c) = 3, Ξ(d) = 4, Ξ(e) = 5, åã³, Ï(ab) = 12, Ï(be) =25, Ï(ed) = 54, Ï(da) = 41, Ï(ac) = 13, Ï(ce) = 35, Ï(bc) = 13, Ï(cd) = 34ãæãç«ã€.ããŠ, ããããçšãããš, é¢ä¿åŒ ;
ΚG(ab) = ab â ΚGââ(Ï(ab)) = ΚGââ(12) = 12 = Ξ(a)Ξ(b)
ΚG(be) = be â ΚGââ(Ï(be)) = ΚGââ(25) = 25 = Ξ(b)Ξ(e)
ΚG(ed) = ed â ΚGââ(Ï(ed)) = ΚGââ(54) = 54 = Ξ(e)Ξ(d)
ΚG(da) = da â ΚGââ(Ï(da)) = ΚGââ(41) = 41 = Ξ(d)Ξ(a)
ΚG(ac) = ac â ΚGââ(Ï(ac)) = ΚGââ(13) = 13 = Ξ(a)Ξ(c)
ãã㯠166ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
G G *
G **
ab
c
d e
1
3 2
4 5
å³ 8.165: å¹³é¢ã°ã©ã G ãšãã®å¹ŸäœåŠçå察ã°ã©ã Gâ. ãããŠ, Gâ ã®å¹ŸäœåŠçå察ã°ã©ã Gââ.
ΚG(ce) = ce â ΚGââ(Ï(ce)) = ΚGââ(35) = 35 = Ξ(c)Ξ(e)
ΚG(bc) = bc â ΚGââ(Ï(bc)) = ΚGââ(23) = 23 = Ξ(b)Ξ(c)
ΚG(cd) = cd â ΚGââ(Ï(cd)) = ΚGââ(34) = 34 = Ξ(c)Ξ(d)
ãæãç«ã€. åŸã£ãŠ, ΚG,ΚGââ ã¯å圢ååãšãªãã®ã§, ã°ã©ã Gãš Gââ ã¯å圢ã§ãã.
2.
(1)ã°ã©ã Gã«å«ãŸããä»»æã®ç¹ vã«å¯Ÿã㊠Ύ †deg(v) ãšããã°, æ¡æè£é¡ã«ãã
nÎŽ â€â
vâV (G)
deg(v) = 2m (8.321)
ãæãç«ã€. äžæ¹, ã°ã©ã G ã«äžè§åœ¢ãç¡ãã®ã§ããã°, ã°ã©ã G ã®å åšã¯ κ = 4 ã§ãããã4 †deg(F), ããªãã¡
4f â€â
fâF (G)
= 2m (8.322)
ãæãç«ã€ã, ãªã€ã©ãŒã®å ¬åŒ : f = 2â n+m ãä»£å ¥ã, é¢æ° f ãæ¶å»ããã°
m †2nâ 4 (8.323)
ãåŸããã. (8.321)(8.323)ãã
nÎŽ †2m †2(2nâ 4) (8.324)
ã€ãŸã
ÎŽ †4â 8n
(8.325)
ãæãç«ã€. åŸã£ãŠ, ÎŽã¯èªç¶æ°ã§ãããã, n ⥠8ã§ãããªãã° ÎŽ †3ãšãªã, 蚌æã¯çµäºãã.ãšããã§, ã°ã©ã Gã«ã¯æ¬¡æ° 3以äžã®ç¹ããããªãã°ä»»æã®ç¹ vã«å¯Ÿã, 3 †deg(v)ãæãç«ã€ã¹ãã ã, æ¡æè£é¡ããçŽã¡ã«
3n â€â
vâV (G)
deg(v) = 2m (8.326)
ãã㯠167ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ã€ãŸã
m ⥠32n (8.327)
ãšãªãã, ãããš (8.323) ãåæã«æãç«ã€ã¹ãã ãã, n㯠3n/2 †2n â 4 ãæºããã¹ãã§ãã,ãã㯠n ⥠8ã§ãã. åŸã£ãŠ, çµå± ÎŽ †3ãšãªã, ã°ã©ãGã«ã¯æ¬¡æ° 3以äžã®ç¹ãããããšãèšãã.
(2) (1) ã®çµæãã, ã°ã©ã Gã«ã¯äžè§åœ¢ã¯ç¡ã, æ¬¡æ° 3以äžã®ç¹ãããããšãã, å³ 8.166ã®ãããªç¹vãååšããããšã«ãªã (ãã®ã°ã©ã Gã®ç¹ã®æ°ã¯ n). åŸã£ãŠ, vã®æ¬¡æ°ã deg(v) < 3ãæºãããªãã°èšŒæã¯çµãã£ãŠããŸãã®ã§, 以äžã§ã¯ deg(v) = 3ãšããŠè°è«ãé²ãã. ãããŠ, å³ 8.166ã®ããã«ç¹ vã®ãŸããã« v1, v2, v3ãé 眮ãããŠãããã®ãšãã.
G
v1v3
v
v2
å³ 8.166: å¹³é¢ã°ã©ã G. ç¹ v ã®åãã«ç¹ v1, v2, åã³, v3 ãé 眮ãããŠãã.
ããŠ,蟺 vv3ãçž®çŽããŠã§ãã (nâ1)ç¹ãããªãã°ã©ãã¯å³ 8.167ã®ããã«ãªã£ãŠãã, ãã® (nâ1)ç¹ããæãã°ã©ã㯠3圩è²å¯èœã§ãããšä»®å®ãã. ãã®ãšã, v1 â α, v2 â α, v3 â β ãšãããã
v1
v2
v3 (v)
α
α
β
å³ 8.167: å¹³é¢ã°ã©ã G ã®ç¹ vv3 ãçž®çŽããã°ã©ã.
圩è²ã, åŸã« vãå ã«æ»ãããšã«ãã (å³ 8.168åç §. ãã®æç¹ã§ç¹ã®æ° n). å ã«æ»ãã vã α, βãš
α
α
β
γ
v1
v2
v
v3
å³ 8.168: å³ 8.167 ã§çž®çŽãã蟺 vv3 ãå ã«æ»ã.
ã¯ç°ãªãè² Î³ ã§åœ©è²ããã°ææã®ã°ã©ã Gã® 3圩è²ãå®æãã. (蚌æçµãã).
(3) K è§åœ¢ãç¡ãã®ã§ããã°, æ¡æè£é¡ãã
(K + 1)f â€â
FâF (G)
deg(F ) = 2m
ãã㯠168ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãæãç«ã€ã, ãªã€ã©ãŒã®å ¬åŒããé¢æ° f ãæ¶å»ããŠ
m â€(K + 1K â 1
)(nâ 2) (8.328)
ãåŸããã. ãããš nÎŽ †2mãçµãã§
ÎŽ †2(K + 1K â 1
)â 4n
(K + 1K â 1
)(8.329)
ãæãç«ã€. åŸã£ãŠ, ã°ã©ã Gã«K è§åœ¢ãŸã§ç¡ã, nãäžçåŒ :
n ⥠4(K + 1K â 1
)(8.330)
ãæºãããªãã°, ã°ã©ã Gã«ã¯æ¬¡æ°ã 2(K + 1/K â 1)â 1以äžã®ç¹ãååšããããšã«ãªã.ãšããã§, äžçåŒ (8.330)ã®æç«æ¡ä»¶ã®åå³ã§ããã, ã°ã©ãã«æ¬¡æ° 2(K + 1/K â 1)â 1以äžã®ç¹ãååšãããšããã°, ããç¹ vã«å¯Ÿã, 2(K + 1/K â 1)â 1 †deg(v) ãæç«ã, ãããšæ¡æè£é¡ãã
m †n
2
{(K + 1K â 1
)â 1
}(8.331)
ãåŸãããã, ãããš (8.328)ãåæã«æç«ããããã«ã¯
n
2
{(K + 1K â 1
)â 1
}â€
(K + 1K â 1
)(nâ 2) (8.332)
ã€ãŸã,
n ⥠4(K + 1K â 1
)(8.333)
ãæãç«ã€ããšã«ãªã, ããã¯äžã«è¿°ã¹ãã°ã©ãã«æ¬¡æ° 2(K + 1/K â 1)â 1以äžã®ç¹ãååšããæ¡ä»¶ã«æµè§Šããªã. åŸã£ãŠä»¥äžã«ãã, ãã®ã°ã©ãã«ã¯æ¬¡æ° 2(K + 1/K â 1)â 1以äžã®ç¹ãååšãããšçµè«ä»ãããã.
ᅵ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 9.4 ã (2005幎床 æŒç¿åé¡ 9 )
次ã®ã°ã©ãã®åœ©è²æ°ãæ±ãã.
(1)åãã©ãã³ã°ã©ã(2)å®å šäžéšã°ã©ã Kr,s,t
(3) k-ç«æ¹äœ
(解çäŸ)
(1)ãã©ãã³ã°ã©ãã¯æç§æž p. 24 å³ 3.5ã«ããããã«å¹³é¢æåå¯èœã§ãã. ãããã®ã°ã©ãã®ãã¡æåã® 3ã€ããããã圩è²ãããš å³ 8.169 ãã, ããããã®åœ©è²æ°ã¯
Ï(æ£åé¢äœ) = 4 (8.334)
Ï(æ£å «é¢äœ) = 3 (8.335)
Ï(ç«æ¹äœ) = 2 (8.336)
ãšãªã. åæ§ã«ããŠ, æ£ 20é¢äœ, åã³, æ£ 12é¢äœã®å¹³é¢æç»ã¯ããããå³ 8.170ã®ããã«ãªã, æ±ãã
ãã㯠169ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
α
β
γΎ
βα
α β
β
α
α βα
β γ
α
βγ
(a)
(b)
(c)
å³ 8.169: (A) æ£åé¢äœ, (B) æ£å «é¢äœ, (C) ç«æ¹äœã®å¹³é¢æç»ãšãã®åœ©è².
α
γ β
α
ΎβΎ
βγ
ÎŽ
α γ
(d) α
γ
α β
γΎ
β
γα
β
γ
β
α
β
β
αγ
αβ
α
(E)
å³ 8.170: (D) æ£ 20 é¢äœ, åã³, (E) æ£ 12 é¢äœã®å¹³é¢æç»ãšãã®åœ©è².
圩è²æ°ã¯
Ï(æ£ 20é¢äœ) = 4, Ï(æ£ 12é¢äœ) = 4 (8.337)
ãšãªã.
(2)å®å šäžéšã°ã©ã Kr,s,t ã®åœ©è²æ°ã¯ãã®å®çŸ©ããçŽã¡ã«
Ï(Kr,s,t) = 3 (8.338)
ã§ãã.
(3) k-ç«æ¹äœ Qk ã¯æ£åäºéšã°ã©ãã§ããããšãèãããš, ãã®åœ©è²æ°ã¯
Ï(Qk) = 2 (8.339)
ã§ãã.
ãã㯠170ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäžï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 9.5 ã (2006幎床 æŒç¿åé¡ 9 )
蟺æ°ãmã§ããã°ã©ã Gã®åœ©è²æ° Ï(G)ã¯äžçåŒ :
Ï(G) †1 +â
8m+ 12
ãæºããããšã瀺ã.(ãã³ã) ã°ã©ãGã®å šãŠã®ç¹ãåã ã«å²ãåœãŠãããè² 1, 2, · · · , Ï(G)ã§ã°ã«ãŒãåãããå Žå,åã°ã«ãŒãå ã®ç¹ã©ããã¯èŸºã§çµã°ããŠã¯ãããªãããšã«çç®ãã. ãã®ãšã Gã«ããã¹ã蟺æ°
mã®æºããã¹ãæ¡ä»¶ãèå¯ãããšè¯ã.
(解çäŸ)ã°ã©ãGã«å«ãŸããç¹ããã®è²ã§ã°ã«ãŒãåããã. 圩è²æ°ã Ï(G)ãªãã°, Ï(G)åã®ã°ã«ãŒããã§ããã¯ãã§ããã, åãã°ã«ãŒãã«å±ããç¹ã®éã«ã¯èŸºãç¡ãããšã«æ³šæãã. ããã¯, ãã, ãã®ãã㪠2ç¹ã®éã«èŸºãååšããŠããŸãã°, ãã® 2ç¹ã¯ãã¯ãåãè²ã§åœ©è²ã§ããªãããšã«ãªã, åãã°ã«ãŒãã«å±ããŠããããšã«ççŸããŠããŸãããã§ãã. åŸã£ãŠ, Gã«èŸºãååšãããšããã°, ããã¯ç°ãªãã°ã«ãŒãã«å±ããç¹ã®éã«ãã蟺ã§ãªããã°ãªãã, ãã®èŸºæ°mã¯ä»»æã® 2ã€ã®ã°ã«ãŒããã 1ç¹ãã€ç¹ãéžãã§ãã® 2ç¹ã蟺ã§çµã¶å Žåã®æ°ãããå€ããªããŠã¯ãããªã. ã€ãŸã, m㯠Ï(G)C2 以äžãšãªãã¯ãã§ãã. ãã£ãŠ
m ⥠12Ï(G)(Ï(G)â 1) (8.340)
ãæãç«ã€ã¹ãã§ãã. ããã Ï(G)ã«ã€ããŠè§£ããš
Ï(G) †12(1 +
â8m+ 1) (8.341)
ãšãªã, ããã¯é¡æã«äžããããäžçåŒã§ãã.ï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 9.6 ã (2005幎床æ å ±å·¥åŠæŒç¿ II(B) #2)
Ï(G) = k ã§ããã,ä»»æã®ç¹ãé€å»ãããšåœ©è²æ°ãå°ãããªããšã, ã°ã©ãG㯠k-èšççã§ãã
ãšãã. ãã®ãšã以äžã®åãã«çãã.
(1) 2-èšççã°ã©ã, 3-èšççã°ã©ããèŠã€ãã.(2) 4-èšççã°ã©ãã®äŸãäžã€æãã.(3) Gã k-èšççã§ãããªãã°, 次㮠(a)(b)ãæãç«ã€ããšã瀺ã.
(a) Gã®ç¹ã®æ¬¡æ°ã¯å šãŠ k以äžã§ãã.(b) Gã«ã«ããç¹ã¯ç¡ã.
(解çäŸ)
(1) 2-èšççã°ã©ã㯠2ç¹ãäžæ¬ã®èŸºã§çµãã§ã§ããã°ã©ã, ã€ãŸã, å®å šã°ã©ãK2ãæãããã. ãŸã,3-èšççã°ã©ãã¯å®å šã°ã©ãK3ããã®äŸã§ãã.
(2) 4-èšççã°ã©ãã®äŸãšããŠå®å šã°ã©ãK4ãæãããã.(3)以äžã§é 次 (a)(b)ã蚌æããŠããã.
(a)ãã k-èšççã°ã©ãããã, c1, · · · , ck ã®èš kè²ã§åœ©è²ãããŠãããã®ãšãã. ä», ã°ã©ãã k-èšççã§ããããšãã, ããäžã€ã®ç¹ãé€ããš c1, · · · , ckâ1 è²ã§åœ©è²ããããšãã§ãã. ãããš, ä»é€ããç¹ã¯ ck ã§å¡ããªããã°ãªããªã. ãªããªãã°, ããããªããã° (k â 1)-圩è²ã«ãªã£ãŠããŸããã
ãã㯠171ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ã§ãã. ããã§ç¹ã®åœ©è²ã®ä»æ¹ã 1éãã§ãããšããããšã¯, ãã®ç¹ã (k â 1)è²ã®ç¹ãšé£æ¥ããŠãããšããããšã§ãããã, ãã®ç¹ã®æ¬¡æ°ã¯ (k â 1)以äžã§ãã.
(b) k-èšççã°ã©ãGã«ã«ããç¹ nãååšãããšä»®å®ãã. nãé€ããš, G㯠A,Bãšãã 2ã€ã®æåã«åé¢ãããã®ãšãã. ä», A,B ã¯ç¬ç«ããŠããã®ã§, Aãš nãããªãã°ã©ããš B ãš nãããªãã°ã©
ãã®ãã¡, å°ãªããšãã©ã¡ããäžæ¹ã¯ k-圩è²ã§ãã. (ã©ã¡ãã kè²æªæºã§åœ©è²å¯èœã§ãããšãããš,A,Bãš nãããããå ã®ã°ã©ãã kè²æªæºã§åœ©è²å¯èœãšãªã£ãŠããŸã.) Aãš nãããªãã°ã©ãã
k-圩è²å¯èœã§ãããšãããš, B ã®ã©ã®ç¹ãåãé€ããŠãäŸç¶ãšããŠã°ã©ã㯠k-圩è²ã§ããççŸ. Bãš nãããªãã°ã©ãã k圩è²ã§ãããšããåæ§ã§ãã. åŸã£ãŠ, k-èšççã°ã©ãã«ã«ããç¹ã¯ååšããªã.
ᅵ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 9.7 ã (2007幎床 æŒç¿åé¡ 9 )
Î(G)ãåçŽã°ã©ã Gã«å±ããæ倧次æ°ãšãã. ãã®ãšã, ä»»æã®åçŽã°ã©ã Gã«å¯ŸããŠ
Ï(G) †1 + Î(G) (8.342)
ãæãç«ã€ããšã瀺ã.
(解çäŸ)Gãç¹æ° 1ã®å€ç«ç¹ã®å Žå, Ï(G) = 1,Î(G) = 0ã§ãããã, åé¡ã®äžçåŒã¯çå·ã§æç«ãã. ç¹æ° nâ 1ã®ãšãã«åé¡ã®äžçåŒã®æç«ãä»®å®ãããš, ç¹æ° nã®ã°ã©ãGã®ä»»æã®ç¹ã vãšã, ãã®ç¹ã Gããåé€
ããã°ã©ãGâ vã«ååšããç¹æ°ã¯ nâ 1ãšãªããã
Ï(Gâ v) †1 + Î(Gâ n) (8.343)
ãæãç«ã€. ã€ãŸã, Gâvã® 1+Î(Gân)-圩è²ãååšãã. ãã®ãããªGâvã® 1+Î(Gân)-圩è²ãäžã€äžãããšã, Gã®äžã®ç¹ vãžã®æ¥ç¶èŸºã¯é«ã Î(G)åã§ãããã, Gâ vã®åœ©è²ã«ã¯Î(G)以äžã®è²ãå¿ èŠãšããªã. åŸã£ãŠ, ãã, Î(Gâ v) = Î(G)ã§ãããªãã° (vã Gã®æ倧次æ°ã®ç¹ã§ã¯ãªãå Žå), Gâ vã®åœ©è²ã§äœ¿ãããŠããè²ãçšã㊠vã圩è²ããããšãã§ãã (Ï(G) = Ï(Gâ v) †1 + Î(Gâ v) = 1 + Î(G)).ãŸã, Î(Gâ v) < Î(G)ã§ãããªãã° (vã Gã®æ倧次æ°ã®ç¹ã®å Žå), G â vã®åœ©è²ã§çšããããè²ã§ãªã 1è²ãçšã㊠vã圩è²ããã°ãã以äžããŸãšãããš, ç¹æ° nã®ã°ã©ã Gã«å¯ŸããŠ
Ï(G) †1 + Î(G) (8.344)
ãæç«ãã.
ãã㯠172ããŒãžç®
173
第10åè¬çŸ©
8.2.2 å°å³ã®åœ©è²
ãã®ç¯ã§ã¯, ãšãŒãããã®ããã«, å€ãã®åœãå±¹ç«ããŠãããããªå°åã®å°å³ã«ãããŠ, é£ãåãåœãç°ãªãè²ã§åºå¥ããããã«ã¯äœè²ãå¿ èŠã ? ãšããçŽ æŽãªè³ªåãã端ãçºãããå°å³ã®åœ©è²ãã«ã€ããŠ, ããã«ãŸã€ããå®çåã³é©çšäŸãèŠãŠããããšã«ãã.
k-é¢åœ©è²å¯èœ : å°å³ã®é£æ¥ãã 2ã€ã®é¢ãåãè²ã«ãªããªãããã« kè²ã§åœ©è²ã§ããå Žå. å³ 8.171 ã« 3-圩è²å¯èœãªã°ã©ãã®äžäŸãèŒãã.
β
α
ÎŽ
αγ
3
1
2
3
1
å³ 8.171: 3-é¢åœ©è²å¯èœãªã°ã©ãã®äžäŸ. é¢ã«ä»ãããæ°åãè²ãè¡šã.
å®ç 19.1
å°å³ Gã 2é¢åœ©è²å¯èœã§ããããã®å¿ èŠååæ¡ä»¶ã¯, Gããªã€ã©ãŒã»ã°ã©ãã§ããããšã§ãã.
(蚌æ)
å¿ èŠæ§ :Gã®åç¹ v ãå«ãé¢ã¯å¶æ°ã§ãªããã°ãªããªãã®ã§,v ã®æ¬¡æ°ã¯å¶æ°ã§ãã. åŸã£ãŠ, å®ç 6.2ãé£çµã°ã©
ãããªã€ã©ãŒã»ã°ã©ãã§ããããã®å¿ èŠååæ¡ä»¶ã¯, Gã®ç¹ã®æ¬¡æ°ãå šãŠå¶æ°ã§ãããããšãã, Gã¯ãªã€ã©ãŒã»ã°ã©ãã§ãã.
ååæ§ :ä»»æã®é¢ F ãéžã³, ãããèµ€ã§åœ©è²ãã. Fã®äžã®ä»»æã®ç¹ xãã, ä»ã®é¢ F
â²ãžè¡ãæ²ç·ãèãã (å³
8.172åç §).
Fâ² â èµ€ (æ²ç·ãå¶æ°æ¬ã®èŸºã亀ããå Žå)
Fâ² â é (æ²ç·ãå¥æ°æ¬ã®èŸºã亀ããå Žå)
ã§è²åããããš, xâ y â x ãšããä»»æã®éè·¯ã¯éæ°åã ã蟺ã亀差ãã (Gã®åç¹ã«æ¥ç¶ãã蟺ã¯å¶æ°)
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
x y
F
Fâ
å³ 8.172: 2-è²é¢åœ©è²å¯èœãªã°ã©ã G ã«ãããŠã¯, x â y â x ãšããä»»æã®éè·¯ã¯å¶æ°å G ã®èŸºãšäº€å·®ãã.
ã®ã§ãã®åœ©è²ã§ççŸã¯ãªã. (蚌æçµãã).
å®ç 19.2Gã¯ã«ãŒãã®ç¡ãå¹³é¢ã°ã©ããšã, Gâ 㯠Gã®å¹ŸäœåŠçå察ã§ãããšãã. ãã®ãšã, Gã k-ç¹åœ©è²å¯èœã§ããããã®å¿ èŠååæ¡ä»¶ã¯, Gâ ã k-é¢åœ©è²å¯èœã§ããããšã§ãã.
äŸãšããŠå³ 8.173ãèŠã.
2
1 3
2
1
3
2
13
1
2
3
G G *
å³ 8.173: 3-ç¹åœ©è²å¯èœãªã°ã©ã G (å·Š) ãš, ãã®å¹ŸäœåŠçå察ã°ã©ã Gâ. ã°ã©ã Gâ 㯠3-é¢åœ©è²å¯èœã§ãã.
å®ç 19.4
Gã¯åç¹ã 3次ã®å°å³ã§ãããšãã. ãã®ãšã, Gã 3-é¢åœ©è²å¯èœã§ããããã®å¿ èŠååæ¡ä»¶ã¯,åé¢ãå¶æ°æ¬ã®èŸºã§å²ãŸããŠããããšã§ãã.
(蚌æ)å¿ èŠæ§ :å³ 8.174ã®ããã«, Gã®ä»»æã®é¢ Fã«å¯Ÿã, Fãåãå²ã Gã®é¢ã¯ 2è²ã«ãã£ãŠåœ©è²å¯èœã§ãã. åŸã£ãŠ,ãã®ãããªé¢ã¯å¶æ°åãªããã°ãªããªãã®ã§, å šãŠã®é¢ã¯å¶æ°æ¬ã®èŸºã§å²ãŸããŠãã.
ååæ§ :ãGãåçŽé£çµã°ã©ãã§ãã, Gã®åé¢ãäžè§åœ¢ã§ãã, Gã®åç¹ã®æ¬¡æ°ãå¶æ° (ãªã€ã©ãŒã»ã°ã©ã)ãªãã°, G㯠3-ç¹åœ©è²å¯èœã§ããããšããå察ãªçµæã瀺ãã°ãã.ã°ã©ã Gã¯ãªã€ã©ãŒã»ã°ã©ãã§ãããã, å®ç 19.1ãã, å³ã®ããã«, Gã®é¢ã¯ 2è², èµ€ãšéã«ãã£ãŠåœ©è²ã§ãã.
èµ€ãé¢ã® 3ç¹ã α, β, γ ãæèšåãã«ããããã«åœ©è²ãã.éãé¢ã® 3ç¹ã α, β, γ ãåæèšåãã«ããããã«åœ©è²ãã.
ãšãããš, ãã®ãããªåœ©è²ã¯ã°ã©ãå šäœã«æ¡åŒµã§ãã. (蚌æçµãã).
ãã㯠174ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
F2 2
1
1
å³ 8.174: é¢ F ãåãå²ãã°ã©ã G ã®é¢ã¯ 2 è²ã§åœ©è²å¯èœã§ãã.
α
γ
β
α
βγB B
B
å³ 8.175: ãªã€ã©ãŒã»ã°ã©ã G ã®é¢ã¯èµ€ãšé (B) 㧠2-é¢åœ©è²å¯èœã§ãã.
8.2.3 蟺圩è²
ç¹åœ©è², å°å³ã®åœ©è² (é¢åœ©è²)ãšããã°, 次ã¯èŸºåœ©è²ã§ãã.
k-蟺圩è²å¯èœ : ã°ã©ã Gã®é£æ¥ãã蟺ã¯åãè²ã«ãªããªãããã«, Gã®èŸºã kè²ã§åœ©è²ã§ãããšã.圩è²ææ° : Gã k-蟺圩è²å¯èœ, k â 1-蟺圩è²äžå¯èœãªãšã, 圩è²ææ° Ï
â²(G)ã
Ïâ²(G) = k
ã§å®çŸ©ãã. å³ 8.176ã« 4蟺圩è²å¯èœãªã°ã©ãã®äžäŸãèŒãã.
1
3
2
1
4
2
3
4
G
å³ 8.176: 4-蟺圩è²å¯èœãªã°ã©ãã®äžäŸ. ãã®ã°ã©ã G ã®åœ©è²ææ°ã¯ Ïâ²(G) = 4 ã§ãã.
ãã㯠175ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
å®ç 20.1
Gã¯åçŽã°ã©ãã§ãã, ãã®æ倧次æ°ãÎãªãã°, Π†Ïâ²(G) †Π+ 1ã§ãã.
ããã§ã¯å ·äœçãªèšŒæãè¿œãããšã¯ãã, ããã€ãã®ä»£è¡šçãªã°ã©ãã«å¯ŸããŠ, äžèšå®çã確èªããããšã«ãšã©ããŠãã.
(äŸ) :
Ïâ²(Cn) =
{2 (n :å¶æ°)3 (n :å¥æ°)
Ïâ²(Wn) = nâ 1 (n ⥠4)
å®ç 20.2
n(ï¿œ= 1)ãå¥æ°ãªãã°, Ïâ²(Kn) = n ã§ãã, å¶æ°ãªãã°, Ï
â²(Kn) = nâ 1 ã§ãã.
(蚌æ)n ⥠3ãšã, 以äžã§ã¯ nãå¶æ°ã®å Žåãšå¥æ°ã®å Žåã«åããŠèããããšã«ãã.
nãå¥æ°ã®ãšã :å®å šã°ã©ãKnã®ç¹ãæ£ nè§åœ¢ã®åœ¢ç¶ã«é 眮ã, ãã®å€åšã®èŸºãå蟺ã«ç°ãªãè²ãçšããŠåœ©è²ã, 次ã«æ®ãã®èŸºããããããããšå¹³è¡ãªå€åšã®èŸºã«çšããããè²ã§åœ©è²ãã (å³ 8.177åç §).
1 2
3
4
5
5
4
3
21
å³ 8.177: å®å šã°ã©ã K5 ã®èŸºåœ©è². å€åŽã® 5 ã€ã®èŸºã«ããããè²ãå²ãæ¯ããš, åå€èŸºã«åããåã蟺ã«åè²ã®è²ãå²ãåœãŠãã°, 5-蟺圩è²ãå®æãã.
ãã®ãšã, åãè²ã§åœ©è²ã§ãã蟺ã®æ倧æ°ã¯ (nâ 1)/2ã§ãã. åŸã£ãŠ, 圩è²ææ°ã nâ 1ãšãããšå®å šã°ã©ã Knã®èŸºæ°ã¯é«ã
12(nâ 1)Ï
â²(Kn) =
12(nâ 1)2 ï¿œ= nC2
ãšãªã, Kn ã®èŸºæ° nC2 = n(nâ 1)/2ã«åãã. åŸã£ãŠ, Ïâ²(Kn) = nã§ãã, ãã®ãšã, 蟺æ°ã¯é«ã
12(nâ 1)Ï
â²(Kn) =
12n(nâ 1) = nC2
ãšãªã, ã€ãã€ãŸãåã. åŸã£ãŠ, nãå¥æ°ã®ãšã㯠Ïâ²(Kn) = nã§ãã.
nãå¶æ°ã®ãšã :Kn ã¯å®å šã°ã©ãKnâ1ãš 1ã€ã®ç¹ã®åãšã¿ãªãã. Knâ1ã®èŸºã¯ nãå¥æ°ã®å Žåã«è¿°ã¹ãæ¹æ³ã«ãã, nâ1
ãã㯠176ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
è²ã§åœ©è²ããããšãã§ãã. åŸã£ãŠ, ãã®æ¹æ³ã§ (n â 1)-圩è²ãããš, å®å šã°ã©ã Knâ1 ã®å蟺ã®æ¬¡æ°ã¯
nâ 2ã§ãããã, åç¹ã«ã¯å š nè²ã®ãã¡, æ¬ ããŠããè²ãå¿ ã 1ã€çã, ãããã®æ¬ è²ã¯å šãŠç°ãªã. ãã£ãŠ, ãããã®æ¬ è²ã§æ®ãã®èŸºã圩è²ããã°, Knã®èŸºåœ©è²ãå®æãã (å³ 8.171åç §). åŸã£ãŠ, n ãå¥æ°ã®ãš
1 2
3
4
5
5
4
3
21
4
1
5
2
3
å³ 8.178: å®å šã°ã©ã K5 ã®å€éšã«ç¹ v ãé 眮ã, ãã®ç¹ãš K5 ã®åç¹ã§ã®æ¬ è²ã§ç¹ v ãçµã¹ã°, nãå¶æ° (ãã®äŸã§ã¯ n = 6) ã®å Žåã® n-蟺圩è²ãå®æãã.
ã, Ïâ²(Kn) = nâ 1 ã§ãã. (蚌æçµãã).ï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 10.1ã (2003幎床 ã¬ããŒãèª²é¡ #9 åé¡ 1 )
ã°ã©ãã®èŸºåœ©è²ã«é¢ããŠä»¥äžã®åã (1)ïœ(3)ã«çãã.
(1)å³ 8.179ã®ã°ã©ã (a)(b)ã®åœ©è²ææ°ãããããæ±ãã.
(2)ããŒã¿ãŒã¹ã³ã»ã°ã©ãã®å€åŽã® 5-éè·¯ã®å¯èœãª 3-圩è²ãå šãŠèããŠ, ããŒã¿ãŒã¹ã³ã»ã°ã©ãã®åœ©è²ææ°ã¯ 4ã§ããããšã瀺ã.
(3)ãã°ã©ãGã 3次ããã«ãã³ã°ã©ããªãã°ãã®åœ©è²ææ°ã¯ 3ã§ãããããšãç¥ãããŠãã. ãã®äºå®ãš (2)ã®çµæãçšããŠ, ããŒã¿ãŒã¹ã³ã»ã°ã©ãã¯ããã«ãã³ã°ã©ãã§ãªãããšã瀺ã.
(a) (b)
å³ 8.179: 圩è²ææ°ãæ±ããã¹ãã°ã©ã (a)(b).
(解çäŸ)
(1)å³ 8.180ãã, (a)(b) ã®ããããã®åœ©è²ææ°ã¯
Ïâ²((a)) = 5 (8.345)
Ïâ²((b)) = 3 (8.346)
ã§ãã.
ãã㯠177ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
(a) (b)
1
2
3
4
1
2
3
5
4
2
3
1
2
1
3
1
3
2
å³ 8.180: 蟺ã«ä»ãããæ°åãåè²ãè¡šã.
(2)ããŒã¿ãŒã¹ã³ã»ã°ã©ãã¯å³ 8.181ã®ããã«åœ©è²ã§ããã®ã§, ãã®åœ©è²ææ°ã¯ 4ã§ãã.
1
2
1
2
3
1
3 3
32
2
2
14 1
å³ 8.181: ããŒã¿ãŒã¹ã³ã»ã°ã©ãã®åœ©è². 蟺ã«ä»ãããæ°åãåè²ãè¡šã.
(3)ããŒã¿ãŒã¹ã³ã»ã°ã©ã㯠3次ã°ã©ã, ã€ãŸã, åç¹ã®æ¬¡æ°ã 3ã§ããã, ãã® 3次ã®ã°ã©ãGãããã«ãã³ã°ã©ãã§ãããªãã° Ï
â²(G) = 3 ã§ããã¯ããªã®ã§, (1)ã®çµæãã, ããŒã¿ãŒã¹ã³ã»ã°ã©ãã¯ãã
ã«ãã³ã°ã©ãã§ã¯ãªãããšãããã.
8.2.4 圩è²å€é åŒ
圩è²å€é åŒ PG(k) : Gã¯åçŽã°ã©ãã§ãããšã, kè²ã§ã®ç¹åœ©è²ã®ä»æ¹ã PG(k)éããããšãã. ãã®ãšã, PG(k)ã圩è²å€é åŒãšåŒã¶.
(äŸ) :
PG(k) = k(k â 1)2 (å³ 8.182(å·Šäž) ã®ãã㪠3ç¹ãããªãæšG)
PG(k) = k(k â 1)(k â 2) (å³ 8.182(å·Šäž) ã®ãããªäžè§åœ¢G)
PG(k) = k(k â 1)nâ1 (å³ 8.182(å³) ã®ãã㪠nç¹ãããªãæš G)
PG(k) = k(k â 1)(k â 2) · · · (k â n+ 1) (å®å šã°ã©ã Kn)
æããã«
k < Ï(G) â PG(k) = 0
k ⥠Ï(G) â PG(k) > 0
ã§ãã.
ãã㯠178ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
k-1 k k-1
k
k-1 k-2
k
k-1
k-1
k-1 k-1 k-1
å³ 8.182: å·Šäžããå³ãž PG(k) = k(k â 1)2, k(k â 1)(k â 2), k(k â 1)n ã圩è²å€é åŒãšããŠæã€ã°ã©ã.
次ã®å®çã¯å ·äœçã«ã°ã©ãGã®åœ©è²å€é åŒãå°åºããéã«æ¥µããŠéèŠã§ãã.
å®ç 21.1
åçŽã°ã©ãGãã蟺 eãåé€ããŠåŸãããã°ã©ããGâ eãšã, çž®çŽa ããŠåŸãããã°ã©ããG/eãšãã. ãã®ãšã
PG(k) = PGâe(k)â PG/e(k) (8.347)
ãæç«ãã.a å床確èªããã, ãçž®çŽããšã¯ä»»æã® 2 ç¹ u, v ãçµã¶èŸº e ãé€å»ã, ç¹ u, v ãåäžèŠããæäœã§ãã.
蚌æã®åã«, ãã®å®çã®ã䜿ãæ¹ããå ·äœçã«æ¬¡ã®äŸãèŠãŠã¿ãã.
(äŸ) : å³ 8.183 ã®äŸã§èãããš, é¢ä¿åŒ (8.347)ã¯
k
k-1
k-2
k-3
k
k-2
k-1
k-2
k-1
k
k-2
v
w
vw
vw=
-
G G-e G\e
å³ 8.183: é¢ä¿åŒ (8.347) ã瀺ãã°ã©ãã®äžäŸ.
k(k â 1)(k â 2)(k â 3) = [k(k â 1)(k â 2)2]â [k(k â 1)(k â 2)]
ãšãªã.
(蚌æ) :e = vwãšãã. Gâ eã¯åé€ãã蟺 eã®äž¡ç«¯ããç°è²ãã§ããããåè²ãã§ãããã®ã©ã¡ããã®å Žåãã
ãªãããšãèãããš, ãã®åœ©è²å€é åŒ PGâe(k)㯠vãš wãç°ãªãè²ã«ãªããããªGâ eã® k-圩è²ã®åæ°ãšvãš wãåè²ã«ãªããã㪠G â eã® k-圩è²ã®åæ°ã®åã«çãããªããã°ãªããªã. ããã§, 以äžã§ãã®è
ãã㯠179ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ããã 2ã€ã®å Žåã«ã€ããŠèå¯ãã.ãŸã, åè , ã€ãŸã, v ãš wãç°ãªãè²ã«ãªããã㪠G â eã® k-圩è²ã®åæ°ã¯ v ãš wãçµã¶èŸº eãæã
ãŠãå€åããªã (å³ 8.183ã®ã°ã©ãG, åã³, G-eãåç §). åŸã£ãŠ, PG(k)ã«çãã. äžæ¹ã®åŸè , ã€ãŸã, vãš wãåãè²ã«ãªããããªGâ eã® k-圩è²ã®åæ°ã¯ vãš wãåäžèŠããŠãå€ãããªã (å³ 8.183ã®ã°ã©ãG-eãš G/eãåç §). åŸã£ãŠ, PG/e(k)ã«çãã. 以äžãã
PGâe(k) = PG(k) + PG/e(k)
ãæãç«ã€. (蚌æçµãã).
圩è²å€é åŒãæ±ããéã®ãã€ã³ãã¯, ã°ã©ã Gã®èŸºæ°ãé¢ä¿åŒ (8.347)ãçšããŠæ®µéçã«åæžããŠè¡ã,ãæšããŸã§å°éããæç¹ã§, nç¹ãããªãæšã®åœ©è²å€é åŒã PG(k) = k(k â 1)nâ1 ã§ããäºå®ãçšããŠæ±ã
ã, ãããã¯, ç°¡åã«åœ©è²å€é åŒãæ±ãŸãã°ã©ããŸã§èŸºæ°ãèœãšããŠ,ããã®ç°¡åãªã°ã©ãã«å¯ŸããŠåœ©è²å€é åŒãæ±ããããšã«ãã.
ãã®æ¹æ³ã«æ £ããããã«ããã€ãã®äŸé¡ãèŠãŠããã.ï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 10.2ã (2003幎床 ã¬ããŒãèª²é¡ #9 åé¡ 2 )
4ã€ã®ç¹ãããªãåçŽé£çµã°ã©ããå šãŠæã, ãããå šãŠã«å¯ŸããŠåœ©è²å€é åŒãèŠã€ã, ãããã®å€é åŒã¯å šãŠ
k4 âmk3 + ak2 â bkãªã圢ã§æžããããšã瀺ã. ãã ã, mã¯èŸºæ°, a, bã¯ãšãã«æ£ã®å®æ°ã§ãã.
(解çäŸ)ãŸã, 4ã€ã®ç¹ãããªãåçŽé£çµã°ã©ããå šãŠæããŠã¿ããš, å³ 8.184ã® AïœFã® 6ã€ã®ã°ã©ããåŸããã.
A B
C D
E F
å³ 8.184: 4 ã€ã®ç¹ãããªãåçŽé£çµã°ã©ã AïœF.
ãŸã, n = 4ã®ãæšãã§ãã A,Bã®åœ©è²å€é åŒã¯å³ 8.185ããçŽã¡ã«ããã
PA(k) = PB(k) = k(k â 1)3 = k4 â 3k3 + 3k2 â k (8.348)
ã§ãã.次ã«, Cã¯å ¬åŒ :
PG(k) = PGâe(k)â PG\e(k) (8.349)
ãã㯠180ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
k k-1 k-1 k-1
k
k-1 k-1k-1
A
B
å³ 8.185: A,B 㯠n = 4 ç¹ãããªããæšãã§ãããã, ãã®åœ©è²å€é åŒã¯ã©ã¡ãã k(k â 1)3.
ãã°ã©ã Cã«é©çšãããš, å³ 8.186ãã
=
e
-
k
k-1
k-1
k-1 k
k-1
k-1C
å³ 8.186: ã°ã©ã C ã¯èŸº e ã«é¢ããŠå³ã®ããã«å解ã§ãã.
PC(k) = k(k â 1)3 â k(k â 1)2 = k4 â 4k3 + 5k2 â 2k (8.350)
ãšãªã.
次ã«ã°ã©ã Dã¯èŸº eã«é¢ããŠå³ 8.187ã®ããã«å解ã§ããã®ã§
e
= -
k
k-1 k-1
k-1
k k-1
k-2
D
å³ 8.187: ã°ã©ã D ã¯èŸº e ã«é¢ããŠå³ã®ããã«å解ã§ãã.
PD(k) = k(k â 1)3 â k(k â 1)(k â 2) = k4 â 4k3 + 6k2 â 3k (8.351)
ãåŸããã.次ã㧠Eã§ããã, ããã¯å³ 8.188ã®ããã«ã°ã©ã Dãš n = 3ã®æšã«å解ã§ã, ã°ã©ã Dã®åœ©è²å€é åŒ
PD(k)㯠(8.351)ã§æ¢ã«æ±ããŠããã®ã§, ãããçšããŠ
PE(k) = PD(k)â k(k â 1)2
= k4 â 4k3 + 6k2 â 3k â (k3 â 2k2 + k) = k4 â 5k3 + 8k2 â 4k (8.352)
ãåŸããã.æåŸã«ã°ã©ã Fã§ããã, ããã¯å³ 8.189ã®ããã«ã°ã©ã Eãšäžè§åœ¢ã«å解ã§ã, ã°ã©ã Eã®åœ©è²å€é åŒ
㯠(8.352)ã§æ¢ã«æ±ããã®ã§ïŒãããçšããŠ
ãã㯠181ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
= -
E D
k k-1 k-1e
å³ 8.188: ã°ã©ã E ã¯èŸº e ã«é¢ããŠå³ã®ããã«å解ã§ãã.
= -e
F Ek k-1
k-2
å³ 8.189: ã°ã©ã F ã¯èŸº e ã«é¢ããŠå³ã®ããã«å解ã§ãã.
PF(k) = PE â k(k â 1)(k â 2)
= k4 â 5k3 + 8k2 â 4k â (k3 â 3k2 + 2k) = k4 â 6k3 + 11k2 â 6k (8.353)
ãåŸããã.
以äžããŸãšãããš
PA(k) = k4 â 3k3 + 3k2 â k (8.354)
PB(k) = k4 â 3k3 + 3k2 â k (8.355)
PC(k) = k4 â 4k3 + 5k2 â 2k (8.356)
PD(k) = k4 â 4k3 + 6k2 â 3k (8.357)
PE(k) = k4 â 5k3 + 8k2 â 4k (8.358)
PF(k) = k4 â 6k3 + 11k2 â 6k (8.359)
ãšãªã, ãããã®å Žåã
PG(k) = k4 âmk3 + ak2 â bk (8.360)
ãšãªã, mã¯èŸºæ°, a, bã¯æ£ã®å®æ°ãšãªã£ãŠããããšãããã.ï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 10.3ã (2004幎床 æŒç¿åé¡ 10 )
å®å šäºéšã°ã©ã, åã³, éè·¯ã°ã©ãã®åœ©è²å€é åŒã«é¢ããŠä»¥äžã®åãã«çãã.
(1)å®å šäºéšã°ã©ã K2,3 ã®åœ©è²å€é åŒ PK2,3(k)ãæ±ãã.(2)å®å šäºéšã°ã©ã K2,s (s : ä»»æã®èªç¶æ°)ã®åœ©è²å€é åŒ PK2,s(k) ãæ±ãã.(3)éè·¯ã°ã©ã C4, åã³, C5ã®åœ©è²å€é åŒ PC4 (k), PC5(k)ãæ±ãã.(4)æ°åŠçåž°çŽæ³ãçšããŠ, éè·¯ã°ã©ã Cn ã«å¯Ÿãã圩è²å€é åŒ PCn(k)ã
PCn(k) = (k â 1)n + (â1)n(k â 1)
ã§äžããããããšã蚌æãã.
(解çäŸ)
ãã㯠182ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
(1)å®å šäºéšã°ã©ã K2,3 ã¯å³ 8.190(å·Š)ã®ãšããã§ãã. 以äž, ç¹ aãšç¹ b ãåè²ã®å Žåãšç°è²ã®å Žåã«
a
b
k
k-1
k-2 k-2 k-2
å³ 8.190: å®å šäºéšã°ã©ã K2,3(å·Š) ãšãã®åœ©è²ã®ä»æ¹ (å³).
åããŠèãã.
(i) ç¹ aãšç¹ bãåè²ã®å Žå, 圩è²ã®æ¹æ³ã¯ k(k â 1)3 éããã.(ii) ç¹ aãšç¹ bãç°è²ã®å Žå, 圩è²ã®æ¹æ³ã¯ k(k â 1)(k â 2)3éãããã (å³ 8.190(å³)åç §).
åŸã£ãŠ, æ±ãã圩è²å€é åŒã¯ãã®äž¡è ã®åãšããŠ
PK2,3(k) = k(k â 1)3 + k(k â 1)(k â 2)2
ã§äžãããã.
(2)å®å šäºéšã°ã©ãK2,sã¯å³ 2.22ã®ãããªã°ã©ãã§ãã. ãã®å³ 8.191ã§ã¯ãäžéå±€ãã®ç¹ã®åæ°ã sã§
a
b
å³ 8.191: å®å šäºéšã°ã©ã K2,s. ãäžéå±€ã㯠s åã®çœäžžãããªã.
ããããšã«æ³šæããã. ãã®ãšã, ãã¯ã, ç¹ aãšç¹ bãåè²/ç°è²ã®å Žåã«åããŠèãã.
(i) ç¹ aãšç¹ bãåè²ã®å Žå : k(k â 1)s éã.(ii) ç¹ aãšç¹ bãç°è²ã®å Žå : k(k â 1)(k â 2)sâéã.
åŸã£ãŠ, æ±ãã圩è²å€é åŒã¯ããã 2ã€ã®å Žåã®åãšããŠ
PK2,s(k) = k(k â 1)s + k(k â 1)(k â 2)sâ1
ã§äžãããã.
ãã㯠183ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
(3)å ¬åŒ :
PG(k) = PGâe(k)â PG/e(k) (8.361)
ãçšãããš, C4ã¯å³ 3.34ã®ããã«ãå解ãããããšãã§ããã®ã§, æ±ãã圩è²å€é åŒã¯
PC4(k) = k(k â 1)3 â k(k â 1)(k â 2) = k(k â 1)(k2 â 3k + 3)
ãšãªã. äžæ¹, C5ã¯, å³ 8.193ã®ããã«å解ã§ããã®ã§, æ±ãã圩è²å€é åŒ PC5(k)㯠PC4 (k)ã®çµæã
= -
ek k-1
k-1 k-1 k-1 k-2
k
C 4
å³ 8.192: éè·¯ C4 ã¯ãã®å³ã®ããã«æšãšäžè§åœ¢ (C3) ãžãšå解ã§ãã.
çšããŠ
PC5(k) = k(k â 1)4 â PC4(k)
= k(k â 1)4 â k(k â 1)(k2 â 3k + 3) = k(k â 1)(k3 â 4k + 6k â 4)
ãšæ±ãŸã.
= -
C 5
C 4
å³ 8.193: éè·¯ C5 ã¯ãã®å³ã®ããã«æšãš C4 ãžãšå解ã§ãã.
(4)éè·¯ã§ãããã, n ⥠2ãšããŠèãã. n = 2ã®ãšãã«ã¯, å³ 8.194ãã, PC2(k) = k(k â 1) ãšãªãã,ããã¯èšŒæãã¹ãé¢ä¿åŒã§ n = 2ãšçœ®ãããã®ã«çãã. ããã§, ç¹ã®æ°ã nâ 1ã®ãšã, é¢ä¿åŒ :
k-1
k
å³ 8.194: éè·¯ C2 ãšãã®åœ©è²æ¹æ³.
PCnâ1(k) = (k â 1)nâ1 + (â1)nâ1(k â 1) (8.362)
ãæç«ãããšä»®å®ãã.
ãã㯠184ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãã®ãšã, å³ 8.195ã®èŸº eã§, å ¬åŒ (8.361)ãçšãããš
PCn(k) = k(k â 1)nâ1 â PCnâ1(k)
= k(k â 1)nâ1 â {(k â 1)nâ1 + (â1)nâ1(k â 1)}= k(k â 1)nâ1 â (k â 1)nâ1 + (â1)n(k â 1)
= (k â 1)n + (â1)n(k â 1)
ãšãªã. åŸã£ãŠ, æ°åŠçåž°çŽæ³ã«ãã, å šãŠã® nã«å¯ŸããŠ
= -
e
C n C n-1
T n
å³ 8.195: éè·¯ Cn ã蟺 e ã«ãããŠå解ãããš, n ç¹ãããªãæš Tn ãšéè·¯ Cnâ1 ãžãšå解ããã.
PCn(k) = (k â 1)n + (â1)n(k â 1)
ãæãç«ã€. (蚌æçµãã).
ᅵ
ᅵ
ᅵ
ãäŸé¡ 10.4ã (2005幎床 æŒç¿åé¡ 10 )
ã°ã©ã Gãéé£çµãªåçŽã°ã©ããªãã°, 圩è²å€é åŒ PG(k)ã¯ãã®æåã®åœ©è²å€é åŒã®ç©ã§äžããããããšã瀺ã.
(解çäŸ)
äŸãã°, äžè§åœ¢ã G1 ãšã, 2åã®ç¹ãããªãæšã G2 ãšãã. ãã®ãšã, 3è²ã䜿ãããšã®ã§ããè²æ°ãšããã°, PG1 (3) = PG2(3) = 6 ã§ãã. å ·äœçã«äžè²ã R,B,G ãšããŠåœ©è²ãå³ç€ºãããšå³ 8.196ã®ããã«ãªã. ããããæããã«, ãã®G1, G2ãã°ã©ãGã® 2ã€ã®æåãšãããšã, ãã® 2ã€ã®æåã¯éé£çµã§ãããã, G1 ã®åœ©è²ã®ä»æ¹ã¯ G2 ã®åœ©è²ã®ä»æ¹ã«åœ±é¿ãäžããªã. åŸã£ãŠ, éé£çµã°ã©ã Gã 3è²ã§è²åãããå Žå, åºæ¥äžããã°ã©ãã®åæ°ã¯ PG1 (3)à PG2(3) = 36 éããã. ãã®èå¯ãæŒãé²ããŠã°ã©ãã®æåæ°ãå¢ããå ŽåãèããŠã, åã ã®åœ©è²å€é åŒã®ç©ã§éé£çµã°ã©ãã®åœ©è²ã®ä»æ¹ã®æ°ã決ãŸãã®ã¯æãããªã®ã§, é¡æãèšããããšã«ãªã.ï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 10.5ã (2006幎床 æŒç¿åé¡ 10 )
ç¹æ° nã®äžè¬ã°ã©ã: G, æš: Tn, å®å šã°ã©ã: Knã®åœ©è²å€é åŒéã«ã¯æ¬¡ã®äžçåŒãæç«ããããšã瀺ã.
PKn(k) †PG(k) †PTn(k)
ãã㯠185ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
R
B G
R
G B
B
R G
B
G R
G
B R
G
R B
R B
B R
R G
G R
B G
GB
å³ 8.196: G1, G2 ã® 3 è²ã§ã®åœ©è²ã®ä»æ¹. ãããã 6 éããã.
(解çäŸ)ãŸã, ç¹æ°ã 4ã®å®å šã°ã©ãK4ãèã, ãã®å®å šã°ã©ããã蟺ã 1æ¬ãã€åæžããŠãã£ãå Žå, 圩è²å€é åŒã¯ã©ã®ããã«æ¯èãã®ãã調ã¹ãŠã¿ãã. å³ 8.197ã«èŒããããã«, 蟺ãåé€ããŠããããšã«ãã, 圩è²
k k-1
k-3 k-2
k
k-1 k-2
k-2
k
k-1 k-1
k-2kk-1
k-1 k-1
å³ 8.197: å®å šã°ã©ããã蟺ã 1 æ¬ãã€åé€ããŠãããšæåŸã«ã¯æšãåŸããã.
å€é åŒã¯ k(kâ 1)(kâ 2)(kâ 3)â k(kâ 1)(kâ 2)2 â k(kâ 1)2(kâ 2)â k(kâ 3)3 ã®ããã«å調ã«å¢å ã, æçµçã«åŸãããã°ã©ãã¯ç¹æ° 4ãããªãæš T4ã§ãã. ãŸã, å®å šã°ã©ãã¯å šãŠã®ç¹ãäºãã«ã€ãªãã£ãŠããã®ã§, ç¹åœ©è²ã«ãããŠã¯å šãŠã®ç¹ã®è²ãä»ã®ã©ã®å šãŠã®ç¹ã®è²ãšãç°ãªãè²ã§åœ©è²ããªããã°ãªãã, åŸã£ãŠ, æããã«äžããããè²ã®æ° kã«å¯Ÿã, å®å šã°ã©ãã®ç¹åœ©è²ã®ä»æ¹ã®æ°ã¯é£çµã°ã©ãäžã§æãå°ãªã. ãŸã, äžèšã®æäœãç¹°ãè¿ããŠæçµçã«ã§ããããé£çµã°ã©ãã¯æšã§ãã, ãã®äºå®ã¯ç¹æ° nã«ãã
ãªã. åŸã£ãŠ
PKn(k) †PG(k) †PTn(k) (8.363)
ããªãã¡
k(k â 1)(k â 2) · · · (k â n+ 1) †PG(k) †k(k â 1)nâ1 (8.364)
ãæãç«ã€.
ãã㯠186ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ä»ãŸã§ã«èŠãããšãããå°ãè€éãªã°ã©ãã«å¯ŸããŠè©ŠããŠã¿ãããã«, 次ã®äŸé¡ããã£ãŠã¿ãã.ï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 10.6ã (2007幎床 æŒç¿åé¡ 10 )
ã«äžããããã°ã©ãã®åœ©è²å€é åŒãæ±ãã.
(解çäŸ)
圩è²å€é åŒãæ±ããéã®ãã€ã³ãã¯è¬çŸ©äžã«ãèšåããããã«, é¢ä¿åŒ:
PG(k) = PGâe(k)â PG/e(k) (8.365)
ãçšããŠã°ã©ãããæšããããã¯ãå®å šã°ã©ãã, ãŸãã¯ç°¡åã«ãã®åœ©è²å€é åŒãæ±ãŸã圢ãŸã§ç°¡ç¥åããããšã§ãã£ã. ãã®åé¡ããã®éãã«ããã°ãã. äŸãã°, åé¡ã®ã°ã©ãGã®å³ 8.198 ã®èŸº e ãéžã³, ãã®
=e -
A BG
å³ 8.198: åé¡ã®ã°ã©ã G ã®å解ã®ç¬¬ 1 ã¹ããã.
蟺ã«å¯ŸããŠé¢ä¿åŒ (8.365)ãçšãããš, Gã¯å³ 8.198 ã®ããã« 2çš®é¡ã®ã°ã©ã A,B ã®å·®ã§æžããããšã«ãª
ã. ããã§, 以äžã§ã¯ã¯ããã«ã°ã©ã A, 次ã«ã°ã©ã B ãšããé çªã§, ããã«åè§£å ¬åŒ (8.365)ã䜿ãããšã«ãã, ããåçŽãªã°ã©ãã«å€åœ¢ããŠããããšã«ãã.
ãŸãã¯ã°ã©ãAã«å¯ŸããŠ, å³ 8.199ã®èŸº eã§å解ãããš, ã°ã©ãAã¯å³ 8.199å³èŸºã®ããã«ã°ã©ãG1, G2
ã«å解ããã. ããã§, ããã«ãã®ã°ã©ã G1, G2ãããããå³ 8.200ã«äžãã蟺ã§å解ãããš, å³ 8.200å³
e
= -
A G1 G2
å³ 8.199: ã°ã©ã A ã®å解ã®ç¬¬ 1 ã¹ããã. ã°ã©ã Aã¯ã°ã©ã G1,G2 ã«å解ããã.
蟺ã®ããã«ãªã. åŸã£ãŠ, ã°ã©ãG1㯠2ã€ã®å®å šã°ã©ãK3ãšã°ã©ãG3ãž, ã°ã©ãG2ã¯ã°ã©ãG3ãšG4
ãžãšãããããå解ãããããšã«ãªã. 2ã€ã®å®å šã°ã©ãã®åœ©è²å€é åŒã¯æ¢ã«èŠãããã« {k(kâ1)(kâ2)}2ã§ããããããã¯ãã®ãŸãŸæ®ããŠããããšã«ããã. ãã£ãŠ, ããšã¯ G3, G4 ãããã«å解ã, ããç°¡åãªã°ã©ãã«ããŠããããšãç®æšãšãªã.
ãã㯠187ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
e
K3 x K3 G3G1
= -
e
= -
G2 G3 G4
å³ 8.200: ã°ã©ã G1, G2 ã®å解.
å®éã«å³ 8.201ã«äžãã蟺 e㧠G3, G4 ãå解ãããšå³ 8.201 ã®å³èŸºã®ããã«ãªã. åŸã£ãŠ, ãããã®å³
= -
e
G3 G5 G6
= -e
G4 G7 T3
å³ 8.201: ã°ã©ã G3, G4 ã®å解.
ã®å³èŸºã«çŸãã, G5, G6, G7 ã, ããç°¡åãªã°ã©ãã§æžãæããããšãã§ããã°, å³ 8.199ã®ã°ã©ã Aã®åœ©
è²å€é åŒãåŸãããããšã«ãªã. ãã¡ãã, å³ 8.201ã®ãå³èŸºãã®æš T3ã®åœ©è²å€é åŒã¯ç°¡å㧠k(kâ 1)2ã§ããããšã«æ³šæããã. å®éã«ã°ã©ã G5, G6, G7 ããããã該åœãã蟺 eã§å解ããŠã¿ããšå³ 8.202ã®å³èŸºããã«ãªã, ãã®æ®µéã§ã¯å šãŠã®ã°ã©ãããæšããããã¯ãå®å šã°ã©ããã§æžãçŽãããŠããããšã«æ³šæãã. ããããåŒã§ãŸãšããŠã¿ããš, å³ 8.199ã®ã°ã©ã Aã®åœ©è²å€é åŒã¯
PA(k) = PG1(k)â PG2(k)
= P{K3}2(k)â PG3(k)â {PG3(k)â PG4(k)}= P{K3}2(k)â 2PG3(k) + PG4(k)
= P{K3}2(k)â 2{PG5(k)â PG6(k)}+ {PG7(k)â PT3(k)}= P{K3}2(k)â 2{PT5(k)â PT4(k)}+ 2{PT4(k)â PT3(k)}+ PT4(k)â PK3(k)â PT3(k)
= P{K3}2(k)â 2PT5(k) + 5PT4(k)â 3PT3(k)â PK3(k) (8.366)
ãã㯠188ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
e = -
G5 T5 T4
e = -
G6 T4 T3
= -e
G7 T4 K3
å³ 8.202: ã°ã©ã G5, G6, G7 ã®å解. å šãŠãæšãšå®å šã°ã©ãã§è¡šçŸã§ããããšã«æ³šæ.
ãšæžãã. nç¹ãããªãå®å šã°ã©ã, æšã®åœ©è²å€é åŒããããã
PKn(k) = k(k â 1)(k â 2) · · · (k â n+ 1) (8.367)
PTn(k) = k(k â 1)nâ1 (8.368)
ã§äžããããããšãæãåºããš, ã°ã©ã Aã®åœ©è²å€é åŒã¯
PA(k) = {k(k â 1)(k â 2)}2 â 2k(k â 1)4 + 5k(k â 1)3 â 3k(k â 1)2 â k(k â 1)(k â 2)
= k6 â 8k5 + 29k4 â 39k3 + 31k2 â 10k (8.369)
ãšãªã.
次ã«ã°ã©ã B ã«ã€ããŠèããã. ã°ã©ã B ãå³ 8.203ã«ç€ºãã蟺 eã§å解ãããš, å³ 8.203ã®å³èŸºã«ç€ºããããã«ã°ã©ãG8ãšå®å šã°ã©ãK4ã§æžãçŽãããšãã§ãã. ãã®å³ 8.203å³èŸºã®ã°ã©ã G8ã¯ããã«
B G8 K4
e
= -
å³ 8.203: ã°ã©ã B ã®å解. ã°ã©ã G8 ãšå®å šã°ã©ã K4 ã§æžãçŽãã.
å³ 8.204ã®ããã«, æ¢ã«åŸãããŠããã°ã©ã G3 ãšæ°ãã«åŸãããã°ã©ã G9 ã«å解ã§ãã. ããã, ããã§æ°ãã«åŸãããã°ã©ãG9ãæŽãªãå解ãæœãããšã§å³ 8.204ã®ããã«æ¢ã«åŸãããŠããG6 ãšå®å šã°ã©
ãã㯠189ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
= -
G8 G3 G9
e
e
G9 G6 K3
= -
å³ 8.204: ã°ã©ã G8 ã®å解. æ¢ã«åŸãããŠããã°ã©ã G3 ãšæ°ãã«åŸãããã°ã©ã G9 ã§æžãçŽãã. ããã, ãã®ã°ã©ã G9 ãæ¢ã«åŸãããŠããã°ã©ã G6 ãšå®å šã°ã©ã K3 ã«å解ã§ãã.
ãK3ã«å解ããããšãã§ããã®ã§, ãããã圩è²å€é åŒã§æžããš
PB(k) = PG8(k)â PK4(k)
= {PG3(k)â PG9(k)} â PK4(k)
= PG3(k)â {PG6(k)â PK3(k)} â PK4(k)
= PG5(k)â 2PG6(k) + PK3(k)â PK4(k)
= PT5(k)â PT4(k)â 2{PT4(k)â PT3(k)}+ PK3(k)â PK4(k)
= PT5(k)â 3PT4(k) + 2PT3(k) + PK3(k)â PK4(k) (8.370)
ãšãªã, ããã§ãå®å šã°ã©ããšæšã®åœ©è²å€é åŒã®ã¿ã§æžãããšãããŸã§å€åœ¢ã§ãã. ããã§, PKn(k), PTn(k)ãä»£å ¥ãããš
PB(k) = k(k â 1)4 â 3k(k â 1)3 + 2k(k â 1)2 + k(k â 1)(k â 2)â k(k â 1)(k â 2)(k â 3)
= k5 â 8k4 + 24k3 â 31k2 + 14k (8.371)
ãåŸããã. ãã£ãŠ, (8.369)(8.371)åŒãã, æ±ãã圩è²å€é åŒã¯
PG(k) = PA(k)â PB(k)
= {k6 â 8k5 + 29k4 â 39k3 + 31k2 â 10k}â {k5 â 8k4 + 24k3 â 31k2 + 14k}= k6 â 9k5 + 37k4 â 63k3 + 62k2 â 24k (8.372)
ãšãªã.
ã¡ãªã¿ã«, åè§£å ¬åŒã䜿ãé, ããã§ç€ºãã蟺ãšã¯ç°ãªã蟺 eã«å¯Ÿã㊠(8.365)åŒãçšããŠãæçµçã«ã¯(8.372)åŒã«èŸ¿ãçãããšã«æ³šæ (éäžã®çµè·¯ãç°ãªã£ãŠã, ã°ã©ã Gã®åœ©è²å€é åŒã¯äžæã«æ±ãŸããªãã
ã°ãªããªã).
ãŸã, ãã®çµæãããèŠãŠã¿ããš, ãã®ã°ã©ãGã®ç¹æ° n, 蟺æ°mã¯ãããã n = 6, m = 9ã§ããã, äž»èŠé 㯠kn, ãã㊠knâ1ã®ä¿æ°ã¯âmãšãªã, åé ã®ç¬Šå·ã¯æ£è² ã亀äºã«çŸããŠãã. ããã¯ãã®ã°ã©ãG
ã®ã¿ã«å¯ŸããŠæãç«ã€äºå®ãªã®ã§ããããïŒ
ãã㯠190ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ããã調ã¹ãããã«æ¬¡ã®ãããªäŸé¡ããã£ãŠã¿ãã.ï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 10.7 ã (2007幎床 æŒç¿åé¡ 12 )
Gã¯ç¹æ° n, 蟺æ°mã®åçŽã°ã©ãã§ãããã®ãšãã. ãã®ãšã, 圩è²å€é åŒ: PG(k)ã®
(i) äž»èŠé 㯠kn ã§ãã.(ii) knâ1 ã®ä¿æ°ã¯âmã§ãã.(iii) åä¿æ°ã®ç¬Šå·ã¯æ£è² ã亀äºã«è¡šãã.
ããããã蟺æ°mã«é¢ããæ°åŠçåž°çŽæ³ã«ãããããã蚌æãã.
(解çäŸ)åè§£å ¬åŒãçšãã圩è²å€é åŒèšç®ã®ç°¡åãªåŸ©ç¿.äžè¬çãªå Žåã«ã€ããŠèšŒæãå§ããåã«, ç¹æ®ãªå ·äœçã°ã©ããäŸã«ãšã, åé¡ã«äžãããã圩è²å€é åŒ
ã«é¢ãã 3ã€ã®æ§è³ªãäºå®ãã©ããã確èªããŠã¿ãããšã«ããã. ç°¡åã®ãã, å ·äœçã«ç¹æ° 4ã®å®å šã°ã©ãK4ãäŸã«ãšã. ãã®ãšã, 圩è²å€é åŒã¯æ¬¡ã®ããã«æžãã.
PK4(k) = k(k â 1)(k â 2)(k â 3) = k4 â 6k3 + 11k2 â 6k (8.373)
åŸã£ãŠ, (i)ã®æ倧åªãæã€äž»èŠé 㯠k4ã§ãã,確ãã« knã§ãã. (ii)ã® knâ1ã®ä¿æ°ã¯â6ã§ããã,å®å šã°ã©ãã®èŸºæ°mãm = n(nâ 1)/2ã§äžããããããšãæãåºããš, n = 4ã§ããä»ã®å Žå, m = 4à 3/2 = 6ã§ãããã, 確ãã« knâ1ã®ä¿æ°ã¯âmãšãªã£ãŠãã. ãŸã, åé ã®ç¬Šå·ãæ£è² ã亀äºã«çŸããŠãã, (iii)ãæãç«ã£ãŠãã. åŸã£ãŠ, 圩è²å€é åŒã«é¢ãã 3ã€ã®æ§è³ªã®ããããã, K4 ãšããç¹æ®ãªã°ã©ãã«å¯ŸããŠ
æãç«ã€ããšãããã£ã. ãã£ãŠ, 以äžã§ã¯ãã®äºå®ãäžè¬ã®ã°ã©ãã«å¯ŸããŠç€ºãã. ãã®é, äŸã«ãã£ãŠå ¬åŒ:
PG(k) = PGâe(k)â PG/e(k) (8.374)
ãçšãã. ãã ã, ããã§ã¯èŸºæ°mã«ã€ããŠã®åž°çŽæ³ãè¡ããã, 蟺æ°m, ç¹æ° nã®ã°ã©ã Gã«å¯Ÿãã圩
è²å€é åŒã P(m,n)G (k)ã®ããã«æžãããšã«ããã. ãã®ãšã, ã°ã©ãGâ eã®èŸºæ°ã¯mâ 1, ç¹æ°ã n, ã°ã©
ã G/eã®èŸºæ°mâ 1, ç¹æ° nâ 1ã§ãããã, ãã®å®çŸ©ã®ããšã§åè§£å ¬åŒã¯
P(m,n)G (k) = P
(mâ1,n)Gâe (k)â P (mâ1,nâ1)
G/e (k) (8.375)
ãšæžãã. 以äžã§ãã®å ¬åŒ (8.375)ãçšããŠèšŒæãè©Šã¿ã.
(i) m = 1ã®ãšã, ã°ã©ã Gã¯ä»»æã® 2ç¹ã 1æ¬ã®èŸºã§çµã°ããŠãã, æ®ã nâ 2ç¹ã¯å€ç«ç¹ã§ããã¹ããªã®ã§, ãã®å Žåã®åœ©è²å€é åŒã¯ä¿æ°ãå«ããŠéœã«æ±ããããšãã§ããŠ
P(1,n)G (k) = k(k â 1)Ã knâ2 = kn â knâ1 (8.376)
ãšãªã. åŸã£ãŠ, æããã«é¡æãæºãããŠããããšãããã. 次ã«èŸºæ°mâ 1ã®å Žåã«é¡æã®æç«ãä»®å®ããã. ã€ãŸã, 圩è²å€é åŒã§æžãã°
P(mâ1,n)
Gâ² (k) = kn +nâ
i=1
αiknâi (8.377)
ã蟺æ°m, ç¹æ° nã®ä»»æã®ã°ã©ãGâ²ã«å¯ŸããŠä»®å®ãã. äžã®åŒã§äž»èŠé ã knãšãªã£ãŠããããšã«æ³šæ
ãããã. ãã®ãšã, ã°ã©ãGããä»»æã®èŸº eãåé€ããã°ã©ãGâ eã®åœ©è²å€é åŒã¯, ã°ã©ãGâ e
ãã㯠191ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ã蟺æ°mâ 1,ç¹æ° nã§ããããšãã, äžã®ã°ã©ã Gâ²ã®ã«ããŽãªãŒã«å ¥ãããšãèããŠ
P(mâ1,n)Gâe (k) = kn +
nâi=1
αiknâi (8.378)
ãšãªã. äžæ¹, Gã®èŸº eãçž®çŽããããšã«ããåºæ¥äžããã°ã©ãG/eã«é¢ãã圩è²å€é åŒã¯, çž®çŽæäœã«ãã£ãŠç¹æ°ã nâ 1ã«ãªã£ãŠããããšã«æ³šæããŠ
P(mâ1,nâ1)G/e (k) = knâ1 +
nâi=2
βiknâi (8.379)
ã§ãã. åŸã£ãŠ, åè§£å ¬åŒ (8.375)ãã, 蟺æ°m, ç¹æ° n ã®ã°ã©ã Gã®åœ©è²å€é åŒã¯
P(m,n)G (k) = kn â (1â α1)knâ1 + (knâ2 以äžã®é ) (8.380)
ãšãªã. åŸã£ãŠ, 蟺æ°mã®å Žåã«ãé¡æãæç«ãã. åŸã£ãŠ, ä»»æã®èªç¶æ°mã«å¯ŸããŠé¡æãæç«ãã.
(ii) m = 1ã®ãšã, æ¢ã«æ±ããŠããããã«
P(1,n)G (k) = kn â knâ1 (8.381)
ã§ããããé¡æã®æç«ã¯æããã§ãã (knâ1 ã®ä¿æ°ãããã§ã®èŸºæ°ã«ãã€ãã¹ç¬Šå·ãä»ãããã® â1ã«ãªã£ãŠãã). ããã§èŸºæ°mâ 1ã®ãšãã«é¡æã®æç«ãä»®å®ãã. ã€ãŸã, 蟺æ°mâ 1, ç¹æ° nã®ã°ã©
ã Gâ²ã«å¯ŸããŠ
P(mâ1,n)G (k) = kn â (mâ 1)knâ1 +
nâi=1
αiknâi (8.382)
ãšããã. ããã§, knâ1 ã®ä¿æ°ãããã§ã®èŸºæ°mâ 1ã«ãã€ãã¹ç¬Šå·ãä»ãããã® â(mâ 1)ã«ãªã£ãŠããããšã«æ³šæãã. ãã®ãšã (i)ãšåæ§ã®èå¯ã«ãã
P(mâ1,n)Gâe (k) = kn â (mâ 1)knâ1 +
nâi=1
αiknâi (8.383)
P(mâ1,nâ1)G/e (k) = knâ1 +
nâi=2
βiknâi (8.384)
ãåŸããã. åŸã£ãŠ, åè§£å ¬åŒ (8.375)ãçšãããšèŸºæ°m, ç¹æ° n ã®ã°ã©ã Gã®åœ©è²å€é åŒã¯
P(m,n)G (k) = kn â (mâ 1)knâ1 â knâ1 + (knâ2 以äžã®é )
= kn âmknâ1 + (knâ2 以äžã®é ) (8.385)
ãšãªã, 蟺æ°mã®å Žåã«ãé¡æãæç«ãã (kn ã®ä¿æ°ã蟺æ°mã«ãã€ãã¹ç¬Šå·ãã€ãããã® âmãšãªã£ã). åŸã£ãŠ, ä»»æã®èªç¶æ°mã«å¯ŸããŠé¡æãæç«ãã.
(iii) m = 1ã®å Žåã«ã¯
P(1,n)G (k) = kn â knâ1 (8.386)
ããé¡æã¯æç«ãã. (ãã®å Žåã«ã¯ 2ã€ã®é ã®ã¿ã§ããããšã«æ³šæ. ããã, ãããã«ããŠã, ãã©ã¹ç¬Šå·ãšãã€ãã¹ç¬Šå·ã亀äºã«çŸããŠãã.) ããã§, 蟺æ°mâ 1ã®å Žåã«é¡æã®æç«ãä»®å®ãã. ã€ãŸã, 圩è²å€é åŒã§æžãã°
P(mâ1,n)
Gâ² (k) = kn +nâ
i=1
(â1)iαiknâi (8.387)
ãã㯠192ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ã蟺æ°m, ç¹æ° nã®ä»»æã®ã°ã©ãGâ²ã«å¯ŸããŠä»®å®ãã. ãã ã, é ããšã®ç¬Šå·ããã¡ã¯ã¿: (â1)iã§å°
å ¥ããé¢ä¿ã§, å šãŠã®ã€ã³ããã¯ã¹ iã«å¯Ÿã㊠αi > 0ã§ãããšããŠä»¥äžã®è°è«ãé²ããªããŠã¯ãªããªãããšã«æ³šæããã. ãŸã, ãã®ãã¡ã¯ã¿ (â1)iãã, 蟺æ°mâ 1ã®ãšã亀äºã«ãã©ã¹ã»ãã€ãã¹ã®ç¬Šå·ãçŸããããšã«æ³šæãã. ãããš, (i)(ii)ãšåæ§ã®èå¯ã«ãã
P(mâ1,n)Gâe (k) = kn +
nâi=1
(â1)iαiknâi (8.388)
P(mâ1,nâ1)G/e (k) = knâ1 â
nâi=2
(â1)iβiknâi (8.389)
ãåŸããã. αi ãšåæ§ã®çç±ã§, å šãŠã® iã«å¯Ÿã㊠βi > 0ã§ãã. åŸã£ãŠ, åè§£å ¬åŒ (8.375)ãçšãããšèŸºæ°m, ç¹æ° n ã®ã°ã©ã Gã®åœ©è²å€é åŒã¯
P(m,n)G (k) = kn â knâ1 + (â1)α1k
nâ1 +nâ
i=2
(â1)i(αi + βi)knâi
= kn âmknâ1 +nâ
i=2
(â1)i(αi + βi)knâi (8.390)
ãšãªã. ãã㧠(ii)ã§ç€ºãããäºå®: α1 = mâ 1ãçšãã. αi + βi > 0ãã, mã®ãšãã®é¡æã®æç«(ãã©ã¹ã»ãã€ãã¹ã®ç¬Šå·ã亀äºã«çŸãã)ã瀺ããã®ã§, ä»»æã®èªç¶æ°mã«å¯ŸããŠé¡æãæç«ãã.
ãã㯠193ããŒãžç®
195
第11åè¬çŸ©
9.1 æåã°ã©ã
ä»ãŸã§æ±ã£ãŠããã°ã©ãã¯å蟺ã«åãã¯ç¡ã, äŸãã°, ãªã€ã©ãŒå°éãªã©ãèããéã«ã¯, 蟺ã®ã©ã¡ãåãã«é²ãã§éãäœã£ãŠãæ§ããªãã£ã. ããã«å¯Ÿã, ãã®ç¯ããã¯å蟺ãããããåããæã£ãŠãããæåã°ã©ããã«ã€ããŠ, ãã®æ§è³ªã調ã¹ãŠè¡ãããšã«ãã.
9.1.1 æåã°ã©ãã®å®çŸ©ã»æŠå¿µãšãã®æ§è³ª
匧éå (arc family) A(D) : ç¹éå V (D)ã®å ã®é åºå¯Ÿãããªãæéæ.æåã°ã©ã (digraph) D : V (D)ãš A(D)ãããªãã°ã©ã (å³ 9.205åç §).
u
v
w
z
D
å³ 9.205: æåã°ã©ã D ã®äžäŸ. V (D) = {u, v, w, z}, A(D) = {uv, vv, vw, vw, wv, wu, zw}.
Dã®åºç€ã°ã©ã (underlying graph) : æåã°ã©ã Dã®ç¢å°ãåãé€ããã°ã©ã (å³ 9.205åç §).
u
v w
z
å³ 9.206: å³ 9.205 ã®æåã°ã©ãã«å¯Ÿããåºç€ã°ã©ã.
åçŽæåã°ã©ã (simple digraph) : Dã®åŒ§ãå šãŠç°ãªã, ã«ãŒããç¡ãã°ã©ã.(泚) : åçŽæåã°ã©ãã®åºç€ã°ã©ãã¯å¿ ãããåçŽã°ã©ãã§ã¯ç¡ã (å³ 9.207åç §).æåã°ã©ãã®å圢 : åºæ¬ã°ã©ãã®éã«å圢ååããã, åç¹ã®é åºãä¿åããååã«ãªã£ãŠãããšã.äŸãã°, å³ 9.208ã®ã°ã©ã Aãš Bã¯å圢ã§ã¯ãªã. wzã®åããç°ãªãããã§ãã.
æåã°ã©ã Dã®é£æ¥è¡å A = (aij) : èŠçŽ aij ã viãã vj ãžã®ã匧ãã®æ¬æ°ãè¡šã, ãµã€ãº nã®ã°ã©ãã«
察ã㊠nà nã®è¡å.
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
u
v w
z
v
u
w
z
å³ 9.207: å³ 2.17 ã®åçŽæåã°ã©ãã®åºç€ã°ã©ãã¯å¿ ãããåçŽã°ã©ãã§ã¯ãªã.
u
v
w
z
u
v w
z
A B
å³ 9.208: ãããæåã°ã©ã A ãš B ã¯å圢ã§ã¯ãªã. 蟺 wz ã®åããç°ãªãããã§ãã.
(泚) : ç¡åã°ã©ãã®å Žåãšç°ãªã, è¡åAã¯é察称ã§ããããšã«æ³šæãããã.å³ 9.209ã®æåã°ã©ã Dã®é£æ¥è¡åAã¯
A =
ââââââ
0 1 0 00 1 2 01 1 0 00 0 1 0
ââââââ
ã§äžãããã.
1
2
3
4
å³ 9.209: ãã®é£æ¥è¡åã ã§äžããããæåã°ã©ã D.
匷é£çµ (strongly connected) : ä»»æã® 2ç¹, v, wã®éã« vãã wãžã®éããã.åãä»ãå¯èœ (orientable) : ã°ã©ã Gã®å šãŠã®èŸºãæ¹åä»ããŠåŒ·é£çµæåã°ã©ããåŸããããšã (äŸãšããŠå³ 9.210åç §).
å®ç 22.1
é£çµã°ã©ã Gãåãä»ãå¯èœã§ããããã®å¿ èŠååæ¡ä»¶, ã°ã©ãGã®å蟺ãå°ãªããšã 1ã€ã®éè·¯ã«å«ãŸããŠããããšã§ãã.
(蚌æ)å¿ èŠæ§ã¯æãããªã®ã§ååæ§ã瀺ã.ãŸã, ã°ã©ãGã®å šãŠãéè·¯ãå«ãŸããŠããå Žåã«ã¯èšŒæã¯çµãã. åŸã£ãŠ, 以äžã§ã¯ãã以å€ã®å Žåãèãã.
ãã㯠196ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
å³ 9.210: åãä»ãå¯èœãªã°ã©ãã®äžäŸ.
ããŠ, éè·¯ Cã«ã¯å«ãŸããªãã, Cã®å蟺ã«é£æ¥ããŠãã蟺 eãéžã¶ (å³ 9.211åç §). ãã°ã©ãGã®å蟺
e C
C
â
å³ 9.211: éè·¯ C ãš Câ².
ãå°ãªããšã 1ã€ã®éè·¯ã«å«ãŸããŠãããã®ã§ãããã, eã¯ããéè·¯ Câ²ã«å«ãŸããŠãã. C
â²ã®èŸºã Cã«
ãå«ãŸããŠãã Câ²ã®èŸºã®åãã¯å€ããªãã§åãä»ãã. ãã®æäœã§ã§ããæåã°ã©ãã¯åŒ·é£çµã§ãã.
åŸã£ãŠ, ãã®æäœãç¶ããŠ, åã¹ãããã§å°ãªããšã 1ã€ã®èŸºãåãä»ãã. åã¹ãããã§æåã°ã©ãã¯åŒ·é£çµãªã®ã§, ã°ã©ãå šäœãåãä»ããåŸã«ã§ããã°ã©ãã¯åŒ·é£çµã§ãã. (蚌æçµãã).æåã°ã©ãã®å¿çšåé¡ãšããŠ, 次ã®äŸé¡ãèŠãŠããã.ï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 11.1 ã (2003幎床 ã¬ããŒãèª²é¡ #10 åé¡ 2 )
å³ã®ãããã¯ãŒã¯ã§ç¹ Aããç¹ Gãžã®æé·è·¯ãèŠã€ãã.
A
B
C F
D
E
G
30
50
19
6
12 23
35
40
10
11
20
8
(解çäŸ)ç¹ Aããã®åç¹ Vãžã®æé·è·¯ã®é·ãã瀺ãæ°å€ l(V) èšç®ãããš
A : 0
B : l(A) + 30 = 30
C : l(A) + 50 = 50
D : max{l(B) + 6, l(C) + 12} = max{36, 62} = 62
F : max{l(D) + 23, l(C) + 10} = max{85, 60} = 85
E : max{l(B) + 40, l(B) + 35, l(F) + 11} = max{70, 97, 96} = 97
G : max{l(E) + 8, l(F) + 20} = max{105, 105} = 105
ãšãªããã, æé·è·¯ã®é·ã㯠105ã§ãã, æé·è·¯ãå³ 9.212 ã«èŒãã.
ãã㯠197ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
A
C
B E
D
F
G A
C
B E
D
F
G50
1223
20 50 12
35
8
å³ 9.212: æé·è·¯ãäžãã 2 éãã®çµè·¯. ã©ã¡ããæé·è·¯ã®é·ã㯠105 ã§ãã.
ᅵ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 11.2 ã (2003幎床 ã¬ããŒãèª²é¡ #10 åé¡ 1 )
æåã°ã©ã Dã®é D 㯠Dã®èŸºã®åããå転ããŠåŸããã. 以äžã®åé¡ã«çãã.
(1)ãã®éãšå圢ã§ãããããªæåã°ã©ãã®äžäŸãæã.(2) Dãš Dã®é£æ¥è¡åã®éã«ã¯ã©ããªé¢ä¿ãããã, çãã.
(解çäŸ)
(1)äºãã«å圢ã§ãããããªæåã°ã©ã Dåã³, ãã®é Dãå³ 9.213 ã«æã.
A B A B
D D-
å³ 9.213: äºãã«å圢ã§ãããããªæåã°ã©ã D åã³, ãã®é Dã®äžäŸ.
(2)å³ 9.214 ã«èŒããåºç€ã°ã©ã Gã«å¯ŸããŠæåã°ã©ã Dåã³, ãã®é Dãäœã, ããããã®é£æ¥è¡åAG,AD,AD ãæžãäžããŠã¿ããš
1
2 3
45
1
2 3
45
1
2 3
45
D D -
G
å³ 9.214: äŸãšããŠèããåºç€ã°ã©ã G, æåã°ã©ã D åã³, ãã®é D.
AG =
ââââââââ
1 2 0 1 02 0 1 0 00 1 0 1 01 0 1 0 10 0 0 1 0
ââââââââ , AD =
ââââââââ
1 1 0 0 01 0 1 0 00 0 0 1 01 0 0 0 10 0 0 0 0
ââââââââ , AD =
ââââââââ
1 1 0 1 01 0 0 0 00 1 0 0 01 0 1 0 00 0 0 1 0
ââââââââ
(9.391)
ãã㯠198ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãšãªã. AD + AD ãäœã£ãŠã¿ããš
AD + AD =
ââââââââ
2 2 0 1 02 0 1 0 00 1 0 1 01 0 1 0 10 0 0 1 0
ââââââââ
(9.392)
ãåŸãããã, ããã¯äžè¡äžåæå ([AD + AD]11) ã ããç°ãªã以å€ã¯åºç€ã°ã©ãã®é£æ¥è¡åãšäžèŽãã. ãã®é£ãéããçããæåã¯åºç€ã°ã©ãã®ãã«ãŒããã«çžåœãã. åŸã£ãŠ, ã«ãŒããç¡ãåºç€ã°ã©ãã«é¢ããŠã¯é¢ä¿åŒ :
AG = AD + AD (9.393)
ãæç«ããããšãããã. ã«ãŒããå«ãã°ã©ãã«é¢ããŠã, é察è§æåã«éãã°äžé¢ä¿åŒãæãç«ã€.
ããã§ã¯å³ 9.214ã«èŒããç¹å®ã®ã°ã©ãã«é¢ããŠè°è«ããã, ãããäžè¬ã®ã°ã©ãã«é¢ããŠãæãç«ã€ã®ã¯æããã§ãã. ã°ã©ãã®éã¯èŸºã®åããé転ããŠã§ããããã§ãããã, äžæ¹ã®ã°ã©ãã§åŒ§vw ãååšãããªãã°ïŒãã®éã®ã°ã©ãã§ã¯ vw ã¯ååšããªã. åŸã£ãŠ, ã«ãŒããç¡ãå Žåã«ã¯é¢ä¿åŒ (9.393)ã®é察è§æåã«é¢ã㊠[AG]vw = [AD + AD]vw ãæãç«ã€. ã«ãŒããããå Žåã«ã¯åé£æ¥è¡åã«å¯Ÿã㊠[AD]vv = [AD]vv ãæãç«ã€ããã§ããããïŒé¢ä¿åŒ (9.393) ã®å¯Ÿè§æåã«é¢ããŠ2[AG]vv = [AD + AD]vv ãæãç«ã€. ã«ãŒããç¡ãå Žåã«ã¯é£æ¥è¡åã®å¯Ÿè§æåã¯ãŒãã§ãããã,é¢ä¿åŒ (9.393)ãæåã§æžãã°å šãŠã®å Žåã«é¢ããŠ, ç°ãªãä»»æã® 2ç¹ v, wã«å¯Ÿã
[AG]vw = [AD + AD]vw (9.394)
2[AG]vv = [AD + AD]vv (9.395)
ãæãç«ã€.
9.1.2 ãªã€ã©ãŒæåã°ã©ããšããŒãã¡ã³ã
é£çµæåã°ã©ã Dã®å šãŠã®åŒ§ãå«ãéããå°éãååšããå Žå, ãã®æåé£çµã°ã©ãDããªã€ã©ãŒã§ãããšèšã. å³ 9.215ã«èŒããäŸã¯, ãªã€ã©ãŒã§ã¯ãªãã, ãã®åºç€ã°ã©ãã¯ãªã€ã©ãŒã§ããå Žåã§ãã.
u
v w
å³ 9.215: ãªã€ã©ãŒæåã°ã©ãã§ã¯ãªãã, ãã®åºç€ã°ã©ãã¯ãªã€ã©ãŒã§ããã°ã©ãã®äžäŸ.
åºæ¬¡æ° (out-degree) outdeg(v) : vwã®åœ¢ãããæåã°ã©ã Dã®åŒ§æ°.å ¥æ¬¡æ° (in-degree) indeg(v) : wvã®åœ¢ãããæåã°ã©ã Dã®åŒ§æ°.
ãã㯠199ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
æ¡ææåè£é¡
æåã°ã©ã Dã®å šç¹ã«ã€ããŠã®å ¥æ¬¡æ°ã®åèšãšåºæ¬¡æ°ã®åèšã¯çãã.
å®ç 23.1
é£çµæåã°ã©ã D ããªã€ã©ãŒã§ããããã®å¿ èŠååæ¡ä»¶ã¯, D ã®åç¹ã§outdeg(v) = indeg(v)ãæç«ããããšã§ãã.
ããã«ãã³æåã°ã©ã (Hamiltonian digraph) : å šãŠã®ç¹ãå«ãéè·¯ãããæåã°ã©ã.åããã«ãã³æåã°ã©ã (semi-Hamiltonian digraph) : å šãŠã®ç¹ãéãéãããã°ã©ã.
å®ç 23.2Dã¯åŒ·é£çµæåã°ã©ãã§ãã,ç¹ã nåãããšãã. åç¹ vã«å¯Ÿã, outdeg(v) ⥠n/2,ãã€, indeg(v) ⥠n/2 ãªãã°, Dã¯ããã«ãã³æåã°ã©ãã§ãã.
ããŒãã¡ã³ã (tournament) : ä»»æã® 2ç¹ãã¡ããã©ïŒæ¬ã®åŒ§ã§çµã°ããŠããæåã°ã©ã (å³ 9.216åç §).
v
z
y x
w
å³ 9.216: ããŒãã¡ã³ãã®äžäŸ.
å®ç 23.3
(i) ããã«ãã³ã§ãªãããŒãã¡ã³ãã¯å šãŠåããã«ãã³ã§ãã.(ii) 匷é£çµãªããŒãã¡ã³ãã¯å šãŠããã«ãã³ã§ãã.
(蚌æ)
(i) ç¹ nåã®ããŒãã¡ã³ãã¯å šãŠåããã«ãã³ã§ãããšä»®å®ãã. Tâ²ã«ã¯ç¹ã nåããã®ã§, åããã«ãã³
éããã (å³ 9.217åç §).(1) vv1ã Tã®åŒ§ãªãã°, v â v1 â v2 â · · · â vn ãææã®éã§ãã.(2) vv1ã Tã®åŒ§ã§ã¯ãªã, v1vã Tã®åŒ§ã§ããã°, å³ 9.218ã®ããã«ç¹ vi ãéžã¹ã°ãã.(3) vvi ã®åœ¢ããã匧ã Tã«ãªãã®ã§ããã°, v1 â v2 â · · · â vn â vãææã®éã§ãã. (蚌æçµãã).
æåŸã«ããŒãã¡ã³ã (ãããŒãã¡ã³ããæšç§»çã§ããããšããæŠå¿µ)ã«é¢ããäŸé¡ãäžã€èŠãŠããã.
ãã㯠200ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
v1
v2
v3
v i-1
vi
vn
v
T â
T
å³ 9.217: Tâ²ã«ã¯åããã«ãã³éããã.
v
v1
v2
v3v4
v i-1v i
v i+1
v n
å³ 9.218: vv1 ã T ã®åŒ§ã§ã¯ãªã, v1v ã T ã®åŒ§ã§ããã°, å³ã®ããã«ç¹ vi ãéžã¹ã°ãã.ï¿œ
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ãäŸé¡ 11.3 ã (2003幎床 ã¬ããŒãèª²é¡ #10 åé¡ 3 )
ããŒãã¡ã³ããæšç§»çã§ãããšããã®ã¯, 匧 uvãš vwãããã°å¿ ã匧 uwãããããšã§ãã. 以äžã®åãã«çãã.
(1)æšç§»çããŒãã¡ã³ãã®äžäŸãæã.(2)æšç§»çããŒãã¡ã³ãã«ãããŠã¯å šãŠã®ããŒã ã«é äœãä»ããããããšã瀺ã. ãã ã, ã©ã®ããŒã ãããããäžäœã®ããŒã å šãŠãè² ãããŠããªããã°ãªããªããã®ãšãã.
(3)ç¹ã 2å以äžããæšç§»çããŒãã¡ã³ãã¯åŒ·é£çµã«ãªãåŸãªãããšã瀺ã.
(解çäŸ)
(1)æšç§»çããŒãã¡ã³ãã°ã©ãã®äžäŸãå³ 9.219ã«èŒãã.
u
v
w
å³ 9.219: æšç§»çããŒãã¡ã³ãã°ã©ãã®äžäŸ.
(2)å³ 3.47ã«ç€ºããã°ã©ãã«ãããŠ, ç¹ k = u, v, w åºæ¬¡æ° : outdeg(k) åã³ å ¥æ¬¡æ° : indeg(k) ãšé äœã®é¢ä¿ãæžããš
1äœ (u) : outdeg(u) = 2, indeg(u) = 0
2äœ (v) : outdeg(v) = 1, indeg(v) = 1
3äœ (w) : outdeg(w) = 0, indeg(w) = 2
ãã㯠201ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãšãªã. åŸã£ãŠ, outdeg ã®å€ãé (ããã㯠indegã®å°ãªãé ) ã« 1äœãã 3äœãžã®é äœãä»ãããã.ãŸã, æšç§»çããŒãã¡ã³ãã®å®çŸ©ãã outdegããã㯠indegã®æ°ãçããç¹ãçŸããããšã¯ããåŸãªããã, å šãŠã®ããŒã ã«é äœãã€ããããšãã§ãã.
(3)ç¹ã 2å以äžããæšç§»çããŒãã¡ã³ãã®ã°ã©ããªãã°, å¿ ã outdeg(k) = 0ãšãªããããªç¹ kãååš
ãããã, 匷é£çµã«ã¯ãªãåŸãªã.
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ãäŸé¡ 11.4 ã (2005幎床 æŒç¿åé¡ 11 )
以äžã®åãã«çãã.
(1)ããã«ãã³ã»ã°ã©ãã¯å šãŠåãä»ãå¯èœã§ããããšã瀺ã.(2) Kn (n ⥠3), ããã³, Kr,s (r, s ⥠2) ã¯åãä»ãå¯èœã§ããããšã,åã ã®ã°ã©ãã®åãä»ããå ·äœçã«èŠã€ããããšã«ãã瀺ã.
(3)ããŒã¿ãŒãœã³ã»ã°ã©ãã®åãä»ããèŠã€ãã.
(解çäŸ)
(1)ããã«ãã³ã»ã°ã©ãã«ã¯å šãŠã®ç¹ãäžåºŠãã€éã£ãŠå ã«æ»ãããã«ãã³éè·¯ãååšããã®ã§, ãã®éè·¯ã«æ²¿ã£ãŠå蟺ãåãä»ãããã° (ãã®éè·¯ã«å±ããªã蟺ãžã®åãä»ãã®ä»æ¹ã¯ä»»æ), ä»»æã®ç¹ vãã¹
ã¿ãŒãã, ä»»æã®ç¹ wã«å°éã§ããéããã®éè·¯äžã«ããããšã¯æãã. åŸã£ãŠ, ããã«ãã³ã»ã°ã©ãã¯åãä»ãå¯èœã§ãã.
(2)å®å šã°ã©ãKn (n ⥠3)ã®å Žåã«ã¯ä»»æã®ç¹ v ã®æ¬¡æ°ã deg(v) = nâ 1 ã§ãããã, Dirac ã®å®çãã, ã°ã©ãå ã®å šãŠã®ç¹ v ã«å¯Ÿã deg(v) ⥠n/2 ãæç«ããã®ã§ããã«ãã³éè·¯ãååšããããã«ãã³ã»ã°ã©ãã§ãã. åŸã£ãŠ, (1)ã®çµæãã, åãä»ãå¯èœã§ãã. å ·äœçã«ã¯ããã«ãã³éè·¯ã«å±ãã蟺ããŸããã®åãã«åãä»ãã, æ®ãã®èŸºã«ä»»æã«åãä»ããè¡ãã°ãã (å³ 9.220(å·Š)åç §). 次ã«å®
K4 K 2,3
A
B
å³ 9.220: K4 ã®åãä»ã (å·Š) ãš K2,3 ã®åãä»ã (å³).
å šäºéšã°ã©ãKr,s (r, s ⥠2)ã®å Žåã«ã¯, å¿ ãå šãŠã®èŸºã ABABãšããé·ã 4ã®éè·¯ã«å«ãŸããã®ã§(A,Bãšã¯ããããã®ç¹ããã®ã©ã¡ããã«å«ãŸãã 2ã€ã®ã°ã«ãŒããæã), å®ç 22ã»1ãé£çµã°ã©ãã
åãä»ãå¯èœã§ããããã®å¿ èŠååæ¡ä»¶ã¯, å蟺ãå°ãªããšã 1ã€ã®éè·¯ã«å«ãŸããããšã§ããããã, åãä»ããå¯èœã§ãã, ãã®é : ABABã«å蟺ã«å¯Ÿãåãä»ããè¡ãã°è¯ã (å³ 9.220(å³)åç §).
(3)å³ 9.221åç §.
ãã㯠202ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
å³ 9.221: ããŒã¿ãŒã¹ã³ã»ã°ã©ãã®åãä»ã.
ᅵ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 11.5 ã (2006幎床 æŒç¿åé¡ 11 )
v1, v2, · · · , vN ãæåã°ã©ã D ã®ç¹ãšãã. æå aij ãå§ç¹ã vi, çµç¹ã vj ã§ãã Dã®åŒ§ã®åæ°
ãšãããã㪠N ÃN - è¡åAãæåã°ã©ãDã®é£æ¥è¡åãšãããš, Ak ã® (i, j)æåã¯Dã«ãã
ãé·ã kã®æå (vi, vj)æ©éã®åæ°ãšãªãããšã瀺ã.
(解çäŸ)
ãŸãã¯, A2 ã®æåãæžãåºããŠã¿ããš
A2 =
ââââââââ
a11 a12 · · · · · · a1n
a21 · · · · · · · · · · · ·· · · · · · · · · · · · · · ·· · · · · · · · · · · · · · ·an1 · · · · · · · · · ann
ââââââââ
ââââââââ
a11 a12 · · · · · · a1n
a21 · · · · · · · · · · · ·· · · · · · · · · · · · · · ·· · · · · · · · · · · · · · ·an1 · · · · · · · · · ann
ââââââââ
=
ââââââââ
ânl=1 a1lal1
ânl=1 a1lal2 · · · · · · â
l=1 a1lalnânl=1 a2lal1 · · · · · · · · · · · ·· · · · · · · · · · · · · · ·· · · · · · · · · · · · · · ·ân
l=1 anlal1 · · · · · · · · · ânl=1 anlaln
ââââââââ
(9.396)
ãšãªã. åŸã£ãŠ, ãã®ç¬¬ (i, j)æåã¯
[A2]ij =nâ
l=1
ailalj (9.397)
ã§ããã, ãã®åã®äžã§, ailã¯ç¹ viããåºçºããŠç¹ vl ãžè³ã vi â vl ã®åœ¢ã®åŒ§ã®åæ°ãè¡šããŠãã. ãŸã,alj ã¯ç¹ vl ããåºçºããŠç¹ vj ãžè³ã vl â vj ã®åœ¢ã®åŒ§ã®åæ°ãè¡šããŠãã. åŸã£ãŠ, ããããæãåããã ailalj ã¯ç¹ vi ããåºçºã, äžç¶ç¹ vl ãçµç±ã, ç¹ vj ãžè³ã vi â vl â vj ã®åœ¢ããã匧ã®åæ°ã«çãã.åŸã£ãŠ, [A2]ij ã¯å šãŠã®å¯èœãªäžç¶ç¹ã«é¢ããŠåããšã£ããã®ã§ãããã, çµå±, é·ã 2ã® (vi, vj)æåæ©éã®åæ°ãè¡šããŠãã.ãã®è°è«ãAk ãžãšæ¡åŒµããããšã¯ãããã.
[Ak]ij =nâ
l1=1
nâl2=1
· · ·nâ
lkâ1=1
ail1al1l2 · · · alkâ2lkâ1alkâ1j (9.398)
ã§ãããã, ail1 ã¯åŒ§ i â l1 ã®åæ°, al1l2 ã¯åŒ§ l2 â l1 ã®åæ°, .... , alkâ1j ã¯åŒ§ j â lkâ1 ã®åæ°ãªã®ã§,ail1al1l2 · · ·alkâ2lkâ1alkâ1j ã¯äžç¶ç¹ {vl1 , vl2 , · · · , vlkâ1} ãçµç±ããé·ã kã®æåæ©éã®åæ°ãè¡šãããšã«
ãã㯠203ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãªã. ãã£ãŠ, å šãŠã®äžç¶ç¹ã®çµã¿åããã«ã€ããŠåããšã£ã (9.398)åŒã¯é·ã kã® (vi, vj)æåæ©éã®åæ°ãè¡šã.ï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 11.6 ã (2007幎床 æŒç¿åé¡ 11 )
é£æ¥è¡å (ãããã¯ã°ã©ããç¹åŸŽä»ããä»ã®è¡åã䜿ã£ãŠãè¯ã), ããã³, å§ç¹ãšçµç¹ãäžããã°èªåçã«ãã®æçè·¯ãšæçè·¯é·ãåºåãããããªããã°ã©ã ãäœæã, å ·äœçã«å³
S
T
A D
C F
BE
1
3
6 2
5
2
4
7
3
6
4
17
5
2
ã«äžããã°ã©ã (å§ç¹ S, çµç¹ T)ã«å¯Ÿããåäœçµæã瀺ã (ããã°ã©ã ãæ·»ä»ããããš).
(解çäŸ)
äžèšã«ãµã³ãã«ããã°ã©ã ãèŒãã.
/***************************************************************************/
/* Graph Theory 2007 exam.#11 Sample program to find the shortest path */
/* J. Inoue */
/**************************************************************************/
#include<stdio.h>
#define N 8 /* # of points */
/* Main Program */
main()
{
int flag[N]; /* ãã©ã° (ãã®ç¹ãžã®æççµè·¯ã確å®ããã 1, ããªããã° 0) */
int distance[N]; /* åç¹ãžã®æçè·é¢ */
int root_point[N]; /* æççµè·¯äžã®åç¹ã®äžã€æåã®ç¹ */
int i,j;
/* åé åã®åæå */
for(i=0; i <= N-1; i++){
flag[i]=0;
distance[i]=-1;
root_point[i]=0;
}
/* ã°ã©ãã®ããŒã¿æ§é ïŒ8 x 8 é£æ¥è¡å */
/* ç¹ i,jãçµã¶èŸºã®é·ãã<ij>æå */
/* 蟺ãç¡ãç¹å¯Ÿã®æåã¯äŸ¿å®äž-1ãšããŠããããšã«æ³šæ */
int adjacent[N][N]={
{-1,1,3,6,-1,-1,-1,-1},
ãã㯠204ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
{1,-1,5,-1,2,4,-1,-1},
{3,5,-1,2,-1,7,3,-1},
{6,-1,2,-1,-1,-1,6,-1},
{-1,2,-1,-1,-1,1,-1,7},
{-1,4,7,-1,1,-1,4,5},
{-1,-1,3,6,-1,4,-1,2},
{-1,-1,-1,-1,7,5,2,-1}
};
/* ããããã®ç¹ãè¡šãèšå·ã䟿å®äžæ°åã«å¯Ÿå¿ãããŠãã*/
printf("// Define as S==0,A==1,B==2,C==3,D==4,E==5,F==6,T==7 //\n");
printf("\n");
/* åæå */
distance[0]=0; /* åœç¶ç¹ Sãžã®æçè·é¢ã¯ãŒã */
flag[0]=1; /* ãããåœç¶ã ã, ç¹ Sã®ãã©ã°ã« 1ãç«ãŠãŠãã*/
int count=0;
int min, min_number;
/* æªèšªåã®ç¹ãç¡ããªããŸã§ä»¥äžãç¹°ãè¿ã */
while(count<N){
min=-1;
for(i=0; i<=N-1; i++){
/* ãã©ã°ã 1ã®ç¹ãã移åå ãæ¢ã */
if(flag[i]==1){
for(j=0; j<=N-1; j++){
/* æªèšªåãã€ç§»åå¯èœãªç¹ */
if((flag[j]==0) && (adjacent[i][j]!=-1)){
/* æçéã§ããããã®æ¡ä»¶åå² */
if((distance[i]+adjacent[i][j]<min) || (min==-1)){
min=distance[i]+adjacent[i][j];
/* éžæé */
min_number=j; }
/* åéã«å¯Ÿããæçè·¯ãæ°ãã«èŠã€ãã£ããæŽæ° */
if((distance[i]+adjacent[i][j]<distance[j]) || (distance[j]==-1)){
distance[j]=distance[i]+adjacent[i][j];
root_point[j]=i;
}
}
}
}
/* è·é¢æå°ãªãšããã¯æççµè·¯ç¢ºå®ããã®ã§ãã©ã°ã 1ã« */
flag[min_number]=1;
}
count++;
}
ãã㯠205ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
/* æåŸã«èšç®ããŒã¿ãåºå */
for(i=0; i<=N-1; i++){
printf("// The shortest distance to point %d is distance[%d]=%d //\n",i,i,distance[i]);
}
printf("\n");
printf("// The previous point for each point on the shortest path //\n");
printf("\n");
for(i=0; i <=N-1; i++){
printf("root_point[%d]=%d\n",i,root_point[i]);
}
printf("\n");
printf("// The shortest path //\n");
printf("\n");
i=7;
printf("%d",i);
while(i!=0){
printf(" <== %d",root_point[i]);
i=root_point[i];
}
printf("\n");
}
ããã®å®è¡çµæã¯æ¬¡ã®ããã«ãªã.
// Define as S==0,A==1,B==2,C==3,D==4,E==5,F==6,T==7 //
// The shortest distance to point 0 is distance[0]=0 //
// The shortest distance to point 1 is distance[1]=1 //
// The shortest distance to point 2 is distance[2]=3 //
// The shortest distance to point 3 is distance[3]=5 //
// The shortest distance to point 4 is distance[4]=3 //
// The shortest distance to point 5 is distance[5]=4 //
// The shortest distance to point 6 is distance[6]=6 //
// The shortest distance to point 7 is distance[7]=8 //
// The previous point for each point on the shortest path //
root_point[0]=0
root_point[1]=0
root_point[2]=0
root_point[3]=2
root_point[4]=1
root_point[5]=4
root_point[6]=2
root_point[7]=6
ãã㯠206ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
// The shortest path //
7 <== 6 <== 2 <== 0
ãã㯠207ããŒãžç®
209
第12åè¬çŸ©
9.1.3 ãã«ã³ãé£é
ããã§ã¯, èªç¶ç§åŠ, 瀟äŒç§åŠ, å·¥åŠç, æ§ã ãªå Žé¢ã§çšããããããã«ã³ãé£éãã®ã°ã©ããçšããè¡šçŸæ³ã«ã€ããŠåŠã¶.
1次å é æ© : é ã£æããåæå»ã§å³å·Šã«ãããã確ç 1/3, 1/2ã§åã, 確ç 1/6ã§çŸåšã®äœçœ®ã«çãŸã. ãŸã, E1, E6 ã«å°éãããšãã®å Žãé¢ããªããšãã (å³ 9.222åç §). ãã®å Žåã®é ã£æãã®äœçœ® E1, · · · , E6
E1 E2 E3 E4 E5 E6
1/2 1/3
1/6
å³ 9.222: 1 次å é æ©ã®äžäŸ.
ã«æ»åšãã確çããæéã®é¢æ°ãšããŠèª¿ã¹ã.
é ã£æãã®æåã®äœçœ®ãE4, ããªãã¡, x = (0, 0, 0, 1, 0, 0)ã§é ã£æãã®åããæå®ãã. ããã§, ãã¯ãã«xã®åæå iã¯, äœçœ® Eiã«é ã£æãããã確çãè¡šã. åŸã£ãŠ, 1,2 ååŸã«ã¯ãããããã®ç¶æ ãã¯ãã«ã¯
x1 =(
0, 0,12,16,13, 0), x2 =
(0,
14,16,1336,19,19
)
ãšãªã.ãã®ãããªç¶æ ãã¯ãã«ãç®åºããããã«, é·ç§»è¡å (transition matrix) : P = (Pij)ãå°å ¥ãããš
䟿å©ã§ãã. ãã®è¡åã® ij æå Pij ã¯é·ç§»ç¢ºç (transition probability) ãšåŒã°ã, ããæå»ãã 1ååŸã«, é ã£æãã Ei ãã Ej ã«ç§»åãã確çãè¡šã. åŸã£ãŠ, äžã®é ã£æãã®äŸã§ã¯
P =
âââââââââââ
1 0 0 0 0 012
16
13 0 0 0
0 12
16
13 0 0
0 0 12
16
13 0
0 0 0 12
16
13
0 0 0 0 0 1
âââââââââââ
ã§äžãããã.
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ããã§, é ã£æãã®ã¹ã¿ãŒãå°ç¹ã§ã®ç¶æ ãã¯ãã«ã x0 = (p10, p
20, p
30, p
40, p
50, p
60) ãšã, ãããã 1ååŸã®
ç¶æ ãã¯ãã«ã x1 = (p11, p
21, p
31, p
41, p
51, p
61) ãšå®ãããš
x1 = x0P (9.399)
ãªãé¢ä¿ãæãç«ã€. å ·äœçã«æåã§æžãäžããš
(p11, p
21, p
31, p
41, p
51, p
61) = (p1
0, p20, p
30, p
40, p
50, p
60)
âââââââââââ
1 0 0 0 0 012
16
13 0 0 0
0 12
16
13 0 0
0 0 12
16
13 0
0 0 0 12
16
13
0 0 0 0 0 1
âââââââââââ
=(p10 +
p20
2,p20
6+p30
2,p20
3+p30
6+p40
2,p30
3+p40
6+p50
2,p40
3+p50
6+p60
2,p50
6+ p6
0
)(9.400)
ãšãªã. ããã§, äŸãã°
p11 = p1
0 +12p20 (9.401)
㯠t = 0ã« E1ã«ããå Žå, 確ç 1ã§E1ã«ãšã©ãŸã, E2ã«ããå Žå, 確ç 1/2㧠E1ã«ç§»ãããšãæå³ããŠ
ãã.ï¿œ
ᅵ
ᅵ
ãäŸé¡ 12.1 ã (2003幎床 ã¬ããŒãèª²é¡ #10 åé¡ 4 )
P ãšQ ãé·ç§»è¡åãªãã°, P Q ãé·ç§»è¡åã§ããããšãäŸãæããŠç€ºã. ãŸã, P ãšQã®é¢é£æå¹ã°ã©
ããš PQã®éã®é¢ä¿ãäŸãæããŠèª¬æãã.
(解çäŸ)ãŸã, å³ 9.223ã®ãããªç¶æ é·ç§»ã°ã©ãã®é·ç§»è¡å P ã¯
v
vv
1
2
3
1/3
1/3
1/4
1/2
1/3
1/6
1/4
1/6
2/3
å³ 9.223: é·ç§»è¡å P ã§äžããããæåã°ã©ã.
P =
âââ
13
13
13
14
12
14
16
16
23
âââ (9.402)
ãšãªã. äžæ¹, å³ 9.224 ã«äžããç¶æ é·ç§»ã°ã©ãã«é¢ããé·ç§»è¡åQã¯
ãã㯠210ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
v
v
v
1
2
3
1
1/2
1/2
1
å³ 9.224: é·ç§»è¡å Q ã§äžããããæåã°ã©ã.
Q =
âââ
0 12
12
1 0 00 0 1
âââ (9.403)
ãšãªã.äŸãã°, æå» t = 0㧠v1, v2, v3ã«ãç²åããå± ã確çã pv1(0), pv2(0), pv3(0) ãšã, ãããç¶æ ãã¯ãã«ãšã㊠ᅵp(0) = (pv1(0), pv2(0), pv3(0))ãšæžãããšã«ãããš, 次ã®æå» t = 1ã§ã®ç¶æ ãã¯ãã« ï¿œp(1)ã¯
(pv1(1), pv2(1), pv3(1)) = (pv1(0), pv2(0), pv3(0))
âââ
13
13
13
14
12
14
16
16
23
âââ
=(
13pv1(0) +
14pv2(0) +
16pv3(0),
13pv1(0) +
12pv2(0) +
16pv3(0),
13pv1(0) +
14pv2(0) +
23pv3(0)
)
ãšãªã, t = 0ã«ç²åã v1 ã«å± ããšããã° pv1(0) = 1, pv2(0) = pv3(0) = 0ã§ãã, ãã®ãšã, 1ç§åŸã«ããããã®ç¹ã«ç²åã移ã確ç (ååšç¢ºç)ã¯
(pv1(1), pv2(1), pv3(1)) = (1, 0, 0)
âââ
13
13
13
14
12
14
16
16
23
âââ =
(13,13,13
)(9.404)
ãšãªã (å³ 9.223åç §).ããã§, 泚æãã¹ããªã®ã¯, é·ç§»è¡åã«ãããŠã¯åè¡ã®å㯠1ã«ãªã£ãŠããªããã°ãªããªãããšã§ãã.
ããã¯åç¹ãã 1ç§åŸã«ã¯å¿ ã (çŸåšå± ãç¹ãå«ãã) ãã©ãããã«ç§»åããªããã°ãªããªãããã§ãã.ããŠ, è¡åã®ç© PQãèšç®ããŠã¿ããš
PQ =
âââ
13
13
13
14
12
14
16
16
23
âââ âââ
0 12
12
1 0 00 0 1
âââ =
âââ
13
16
12
12
18
38
16
112
43
âââ (9.405)
ãšãªã£ãŠãã, 確ãã«ãã®è¡å PQã®åè¡ã®å㯠1ã«ãªã£ãŠããïŒåŸã£ãŠ, PQã¯é·ç§»è¡åã§ãã. ãã®è¡å PQã§è¡šãããç¶æ é·ç§»ã°ã©ããæããšå³ 9.225ã®ããã«ãªã£ãŠããïŒt = 0 ãã t = 1ãžã® 1ã¹ãããã§ç¶æ ãã¯ãã«ã¯
(pv1(1), pv2(1), pv3(1)) = (pv1(0), pv2(0), pv3(0))
âââ
13
16
12
12
18
38
16
112
34
âââ
ãã㯠211ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
v
vv
1
2
3
1/3
1/6
1/2
1/8
1/2
1/6
3/8
1/12
3/4
å³ 9.225: é·ç§»è¡å PQ ã§äžããããæåã°ã©ã.
=(pv1(0)
3+pv2(0)
2+pv3(0)
6,pv1(0)
6+pv2(0)
8+pv3(0)
12,pv1(0)
2+
3pv2(0)8
+3pv3(0)
4
)(9.406)
ãšãªã.ï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 12.2 ã (2004幎床 åé¡ 11 )
1. æåã°ã©ã Dã®åç¹ãæŽæ°ã®å¯Ÿ : {11, 12, 21, 22} ã§è¡šãã, j = kã®ãšã, ç¹ ij ãš klã匧ã§çµã°ã
ããã®ãšãã. ãã®ãšã, Dãå³ç€ºã, ãã®ãªã€ã©ãŒå°éãååšãããªãã°ãããæ±ãã.
2. ãã«ã³ãé£éãšæåã°ã©ãã«é¢ããŠä»¥äžã®åãã«çãã.
(1)ãã®é·ç§»è¡å P ã
P =
âââ
23
16
16
16
23
16
16
16
23
âââ
ã§äžãããã 3ç¶æ (a,b,cãšåä»ãã)ã®ç¶æ é·ç§»ãè¡šãæåã°ã©ããæã. ãã ã, è¡åã®è¡ã®å¢ããæ¹åã« a,b,cãšç¹ã«ååãä»ããããš.
(2)æå» t = 0ã§, ãã®é ã£æãã aã«ãã, ã€ãŸã, ç¶æ ãã¯ãã«ã x = (1, 0, 0)ãšãããšã, t = 1, 2ã«ãããŠ, ãã®é ã£æãã a,b,cã«å± ã確ç (pa(1), pb(1), pc(1)), åã³, (pa(2), pb(2), pc(2))ãããããæ±ãã.
(3) t = nã§, ãã®é ã£æãã a,b,c ã«å± ã確ç pa(n), pb(n), pc(n)ãããããæ±ãã.
(解çäŸ)
1. {11, 12, 21, 22}ã«ãããŠ, j = kãæãç«ã€ãšãã®ã¿, ç¹ ijãš klã匧ã§çµã°ããããšãèãããš, åç¹ããä»ç¹ãžæãããšã®ã§ãã匧ã¯æ¬¡ã®ããã«ãªã.
11 â 12, 12â{
2122
21 â{
1112
, 22â 21
ãã㯠212ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ã®ããã«ãªã, ãããã®é¢ä¿ãã°ã©ãã§è¡šããšå³ 9.226ã®ããã«ãªã. ãã®å³ 9.226ãã, ãã®ã°ã©
11
2122
12
å³ 9.226: {11, 12, 21, 22} ã«ãããŠ, ãj = k ãæãç«ã€ãšãã®ã¿, ç¹ ij ãš kl ã匧ã§çµã°ãããèŠåã§åºæ¥äžããæåã°ã©ã.
ãã¯é£çµæåã°ã©ã (ããã Dãšåä»ããã)ã§ãã, ãã®é£çµæåã°ã©ã Dããªã€ã©ãŒã»ã°ã©ãã§
ããããã®å¿ èŠååæ¡ä»¶ã¯, Dã®åç¹ã§å ¥æ¬¡æ°ãšåºæ¬¡æ°ãçãã, ã€ãŸã, Dã®ä»»æã®ç¹ v ã«ãããŠ,outdeg(v) = indeg(v)ãæãç«ã€ããšã§ãããã (ååã®å®ç 23.1ãåç §ã®ããš), å³ã®ã°ã©ãã«ãããŠããã調ã¹ããš
outdeg(11) = 1 = indeg(11)
outdeg(12) = 2 = indeg(12)
outdeg(21) = 2 = indeg(21)
outdeg(22) = 1 = indeg(22)
ãšãªã, 確ãã«ãã®æ¡ä»¶ãæºãããŠãã. åŸã£ãŠ, ãªã€ã©ãŒå°éãååšã, ããã¯, 11 â 12 â 21 â12â 22â 21â 11 ã§ãã.
2. åé¡æã«äžããããèªå°ã«åŸã.
(1)é·ç§»ç¢ºçãåé¡æã® P ã§äžããããã°ã©ããæããšå³ 9.227ã®ããã«ãªã. ãã ã, å匧ã«ä»ãããæ°åã¯åç¶æ éã®é·ç§»ç¢ºçãè¡šã.
2/3
2/32/3
a
b c
1/6
1/6
1/6
1/6
1/6
1/6
å³ 9.227: é·ç§»ç¢ºçã P ã§äžãããã 3 ç¶æ a, b, c éé·ç§»ã®æ§åãè¡šãã°ã©ã.
(2)(3)æå» t = n, n + 1ã«ãããç¶æ ãã¯ãã« : xn â¡ (pa(n), pb(n), pc(n)),xn+1 â¡ (pa(n + 1), pb(n +1), pc(n+ 1)) éã«ã¯é·ç§»ç¢ºç P ãä»ããŠ
xn+1 = xnP (9.407)
ãã㯠213ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãªãé¢ä¿, ããªãã¡,
(pa(n+ 1), pb(n+ 1), pc(n+ 1)) = (pa(n), pb(n), pc(n))
âââ
23
16
16
16
23
16
16
16
23
âââ (9.408)
åŸã£ãŠ
pa(n+ 1) =23pa(n) +
16pb(n) +
16pc(n) (9.409)
pb(n+ 1) =16pa(n) +
23pb(n) +
16pc(n) (9.410)
pc(n+ 1) =16pa(n) +
16pb(n) +
23pc(n) (9.411)
ãæãç«ã€. åŸã¯, ãããã®ç¢ºçã«é¢ããé£ç«æŒžååŒã解ãã°ãã. ã©ã®ãããªè§£ãæ¹ã§ãè¯ãã®ã ã,åæå» nã§ã®ç¢ºçã®èŠæ Œåæ¡ä»¶ : pa(n) + pb(n) + pc(n) = 1 (åæå»ã§é ã£æã㯠a, b, cã®ããããã«
ã¯å¿ ãå± ã)ãã, pc(n) = 1â pa(n)â pb(n)ãçšããŠ, é£ç«æŒžååŒãæžãçŽããš
pa(n+ 1) =12pa(n) +
16
(9.412)
pb(n+ 1) =12pb(n) +
16
(9.413)
ãããã¯
(pa(n)pb(n)
)=
(12 00 1
2
)n (pa(0)pb(0)
)+
nâ1âk=0
(12 00 1
2
)k (1616
)(9.414)
ãšãªã. ãã£ãŠ, äŸãã° pa(n)ã®äžè¬é ã¯
pa(n) =12n
pa(0) +16
nâ1âk=0
12k
=12n
pa(0) +16
1â 12n
1â 12
=12n
pa(0) +13
(1â 1
2n
)(9.415)
ãšãªã. åŸã£ãŠ, åœç¶, pb(n)ã
pb(n) =12n
pb(0) +13
(1â 1
2n
)(9.416)
ã§ãã, ãã®ãšã pc(n)ã¯
pc(n) = 1â 12n
(pa(n) + pb(n))â 23
(1â 1
2n
)(9.417)
ãšãªã.åŸã£ãŠ,ããšã¯ããã®é ã£æãã¯æå» t = 0㧠bã«å± ãããšããåææ¡ä»¶ : pa(0) = 0, pb(0) = 1, pc(0) = 0ãäžã«åŸãããäžè¬é ã«ä»£å ¥ããŠ
pa(n) =13
(1â 1
2n
)(9.418)
pb(n) =13
(1 +
12nâ1
)(9.419)
pc(n) =13
(1â 1
2n
)(9.420)
ãåŸããã.
ãã㯠214ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ᅵ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 12.3 ã (2005幎床 æŒç¿åé¡ 12 )
ååã®ãŸããã® 5人 (A, B, C, D, C ãããšåã¥ã, ãã®é ã«æèšãŸããã«çåžããŠãããšãã) ã 1ã€ã®ãµã€ã³ãã§è¡ãã²ãŒã ãèãã. åã©ãŠã³ãã§ãµã€ã³ãã® 1, 2ã®ç®ãåºããšãã«ã¯, ãã®å·Šé£ãã®äººã次ã«æ¯ããã®ãšã, 3, 4, 5ãåºããšãã«ã¯å³é£ãã®äººã次ã«æ¯ããã®ãšã, 6ã®ç®ãåºããšãã«éã, åã人ãããäžåºŠãµã€ã³ããæ¯ããã®ãšãã. ãã®ãšã
(1)é·ç§»è¡åãæžã, ç¶æ é·ç§»å³ãæã.(2)ãã®ãã«ã³ãé£éã¯ãšã«ãŽãŒãçãåŠã, çç±ãä»ããŠçãã.(3)å§ãã« Aããããµã€ã³ããæ¯ããšã, 5ã©ãŠã³ãç®ã«åã³Aããããµã€ã³ããæ¯ãããšã«ãªã確çãæ±ãã.
(解çäŸ)
(1)é·ç§»è¡å P ã¯
P =
ââââââââ
16
13 0 0 1
212
16
13 0 0
0 12
16
13 0
0 0 12
16
13
13 0 0 1
216
ââââââââ
(9.421)
ã§ãã, 察å¿ããç¶æ é·ç§»ã®ã°ã©ãè¡šçŸã¯å³ 9.228ã§ãã.
1/6
1/2
1/3
1/2
1/6
1/3
1/2
1/6
1/3
1/2
1/6
1/3
1/2
1/6
1/3
A
B
CD
E
å³ 9.228: é·ç§»è¡å P ã«å¯Ÿå¿ããæåã°ã©ã.
(2) P 2ãèšç®ããŠã¿ããš
P 2 =
ââââââââ
1336
19
19
14
16
16
1336
19
19
14
14
16
1336
19
19
19
14
16
1336
19
19
19
14
16
1336
ââââââââ
(9.422)
ãšãªãã, ããã¯å šãŠã®è¡åèŠçŽ ãæ£ã®å€ã§ãããããªè¡åã§ãã, åŸã£ãŠ, ä»»æã® n(n ⥠2)ã«å¯ŸããŠã, P nã®è¡åèŠçŽ ã¯å šãŠæ£ã®å€ãæã€.ãåŸã£ãŠ, limnââ P nã®è¡åèŠçŽ ãå šãŠæ£ã§ããã®ã§, ä»»æã®
ãã㯠215ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ç¶æ ããä»»æã®ç¶æ ãžç§»åããããšãå¯èœã§ãã. åŸã£ãŠ, åç¶æ ã¯æ°žç¶ç (iãã jãžã®éãããã°,jãã iãžã®éããã) ãã€éåšæç (pii ï¿œ= 0) ã§ããã®ã§, ãã®ãã«ã³ãé£éã¯ãšã«ãŽãŒãçã§ãã.
(3) P 5ãèšç®ãããš
P 5 =
ââââââââ
14767776
14957776
16007776
14907776
17157776
17157776
14767776
14957776
16007776
14907776
14907776
17157776
14767776
14957776
16007776
16007776
14907776
17157776
14767776
14957776
14957776
16007776
14907776
17157776
14767776
ââââââââ
(9.423)
ã§ããã®ã§, ç¶æ ãã¯ãã«ã x(t) = (pA(t), pB(t), pC(t), pD(t), pE(t)) ãšãããš, ã¯ããã« Aã«ããã®
ã§, x(0) = (1, 0, 0, 0, 0) ã«å¯ŸããŠ
x(5) = x(0)P 5 =(
14767776
,14957776
,16007776
,14907776
,17157776
)(9.424)
ãšãªããã, t = 5ã« Aãããåã³ãµã€ã³ããæ¯ã確ç㯠1476/7776ã§ãã.
ᅵ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 12.4 ã (2006幎床 æŒç¿åé¡ 12 )
ã㌠E1, E2, · · · , E6ã 1次å äžã«å·Šããå³ãžãšãã®é ã«äžŠãã§ãããã®ãšãã. ãã®ãšã, E2ããæ¯æé
ããŒãã¯ããããé ã£æããå·Šã®ããŒã«ç«ã¡å¯ã確çã 1/2, å³ã®ããŒã«ç«ã¡å¯ã確çã 1/3ãšãã. ãŸãåãåºã«ãšã©ãŸã確çã 1/6ãšãã. ãŸã, ã㌠E1 ã¯äŒå¡å¶ã®æ°åã£ãåºã§éäŒå¡ã®é ã£æãã¯æ¥ã
æç¹ã§è¿œã£æãããŠåºã«å ¥ããªããã®ãšãã. ãã®ãšã, ãã®ãã«ã³ãé£éãæåã°ã©ãã§è¡šã. ãŸã, 6æéåŸã«é ã£æããåããŒã«å± ã確ç p1, p2, · · · , p6ãæ±ãã.
(解çäŸ)ã㌠E1 ã«ã¯å ¥ããªãã®ã§, E1 ãã E2 ãžã¯ç¢ºç 1ã§é·ç§»ã, E6 ãåžåå£ã§ããããšã«æ³šæãããš, ãã®é ã£æãã®åããè¡šãæåã°ã©ãã¯å³ 9.229ã®ããã«ãªã. ãŸã, ãã®é ã£æãã®æå» nã§ã®ç¶æ ãã¯ãã«
E1 E2 E3 E4 E5 E6
1
1
1/6
1/2
1/3
1/2
1/6
1/3
1/2
1/6
1/3
1/2
1/6
1/3
å³ 9.229: ã㌠E1 ã§ã¯è¿œã£æãã, ã㌠E6 ã«ã¯å ¥ã£ãããåž°ããªãé ã£æãã®åããè¡šãæåã°ã©ã.
ã x(n) = (p1(n), p2(n), p3(n), p4(n), p5(n), p6(n)) ãšãããš, næéåŸã«åããŒã«ã©ããããã®ç¢ºçã§å± ãããšã«ãªãã®ãã¯é·ç§»è¡åA :
A =
âââââââââââ
0 1 0 0 0 012
16
13 0 0 0
0 12
16
13 0 0
0 0 12
16
13 0
0 0 0 12
16
13
0 0 0 0 0 1
âââââââââââ
(9.425)
ãã㯠216ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ã«å¯ŸããŠ
xn = x0An (9.426)
ã§äžããããã®ã§, n = 6,x0 = (0, 1, 0, 0, 0, 0)ã«æ³šæããŠäžåŒãèšç®ããã°ãã. æã§èšç®ããã®ã¯ãšãŠãé¢åãªã®ã§, ããã§ã¯æ¬¡ã®ããã°ã©ã ãçšããŠèšç®æ©ã«èšç®ãããããšã«ãã.
/************************************************************/
/* Calculation of time evolution of probability for */
/* 1-dimensional random walk */
/* J. Inoue */
/***********************************************************/
#include<stdio.h>
#define tmax 10
main(){
FILE *pt;
double a[6][6],b[6][6];
int i,j,k,t;
for(i=0; i<=5; i++){
for(j=0; j<=5; j++){
b[i][j]=0;
}}
/* Definition of transition matrix A (definition of digraph) */
a[0][0] = 0;
a[0][1] = 1.0;
a[0][2] = 0;
a[0][3] = 0;
a[0][4] = 0;
a[0][5] = 0;
a[1][0] = 1.0/2;
a[1][1] = 1.0/6;
a[1][2] = 1.0/3;
a[1][3] = 0;
a[1][4] = 0;
a[1][5] = 0;
a[2][0] = 0;
a[2][1] = 1.0/2;
a[2][2] = 1.0/6;
a[2][3] = 1.0/3;
a[2][4] = 0;
a[2][5] = 0;
a[3][0] = 0;
a[3][1] = 0;
a[3][2] = 1.0/2;
ãã㯠217ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
a[3][3] = 1.0/6;
a[3][4] = 1.0/3;
a[3][5] = 0;
a[4][0] = 0;
a[4][1] = 0;
a[4][2] = 0;
a[4][3] = 1.0/2;
a[4][4] = 1.0/6;
a[4][5] = 1.0/3;
a[5][0] = 0;
a[5][1] = 0;
a[5][2] = 0;
a[5][3] = 0;
a[5][4] = 0;
a[5][5] = 1.0;
/* Calculation of A^{t} */
if((pt=fopen("matprod.txt","wt")) !=NULL){
for(i=0; i<=5; i++){
for(j=0; j<=5;j++){
if((i==0) && (j==0)){fprintf(pt,"Time Step=%d\n\n",1);}
if(j!=5){
fprintf(pt,"A(%d)(%d,%d)=%lf ",t,i+1,j+1,a[i][j]);
}else{
fprintf(pt,"A(%d)(%d,%d)=%lf\n",t,i+1,j+1,a[i][j]);}
}}
for(i=0; i<=5; i++){
fprintf(pt,"\n t=%d p(%i)=%lf",1,i+1,a[1][i]);
//fprintf(pt,"%d %lf ",1, a[1][i]);
}
fprintf(pt,"\n %c", â\nâ);
for(t=1;t<=tmax;t++){
for(i=0; i<=5; i++){
for(j=0; j<=5;j++){
for(k=0; k<=5; k++){
b[i][j] = b[i][j] + a[i][k]*a[k][j];
}
}
}
for(i=0; i<=5; i++){
for(j=0; j<=5;j++){
if((i==0) && (j==0)){fprintf(pt,"Time Step=%d\n\n",t+1);}
ãã㯠218ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
if(j!=5){
fprintf(pt,"A(%d)(%d,%d)=%lf ",t+1,i+1,j+1,b[i][j]);
}else{
fprintf(pt,"A(%d)(%d,%d)=%lf\n",t+1,i+1,j+1,b[i][j]);}
}}
for(i=0; i<=5; i++){
fprintf(pt,"\n t=%d p(%i)=%lf ",t+1,i+1,b[1][i]);
//fprintf(pt,"%d %lf ",t+1,b[1][i]);
}
fprintf(pt,"\n %c", â\nâ);
for(i=0; i<=5; i++){
for(j=0; j<=5; j++){
a[i][j]=b[i][j];
}
}
for(i=0; i<=5; i++){
for(j=0; j<=5; j++){
b[i][j]=0;
}}
}
}
fclose(pt);
}
çµæãã°ã©ãã«ããŠããããããŠã¿ããšæ¬¡ã®ããã«ãªã. ãã®å³ 9.230 ãã, åžåå£ã§ãã 6çªç®ã®ããŒä»¥
0
0.2
0.4
0.6
0.8
1
0 2 4 6 8 10 12
p1p2p3p4p5p6
P
t
å³ 9.230: é ã£æããåããŒã«å± ã確çã®æéå€å.
å€ã®åããŒã®æ»åšç¢ºçã¯æéãšãšãã«æžå°ã, ãŒããžãšåãã, ãã®åã®ç¢ºçãã㌠6ã«æµããŠè¡ã, 11æ
ãã㯠219ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
éåŸã«ã¯é ã£æãã¯ç¢ºç 1㧠6çªç®ã®ããŒã«å± ãããšã«ãªã.
⻠泚 : 1æéåŸã« P (1)ããŒãã§ãªãã®ã¯äžæè°ã«æããããããããªãã, äŸãã° 1æéåŸã«ã¯ç¢ºç 1/2ã§ããŒE2ããE1ãžåããããšã«ãªã, ãã®æå³ã§ããŒE1ã®åã«ã¯ãå± ããããšã«ãªã. ããã,ãE1ã«
æ»åšããããšããã®ã¯ã次ã®ã¹ãããã§ãåãã㌠E1ã«çãŸããããšãæå³ã, ããã§ã¯ãããèš±ãããŠããªã. ã€ãŸã, æ¡ä»¶ã€ã確ç P (Xt+1 = E1|Xt = E1) = 0ã§ãã, ããã¯é·ç§»è¡åã® (1, 1)æåããŒãã§ããããšã«åæ ããŠããããã§ãã.
ãã㯠220ããŒãžç®
221
第13åè¬çŸ©
10.1 ãããã³ã°, çµå©, Menger ã®å®ç
æçµåã§ããä»åã®è¬çŸ©ã§ã¯, ãããã³ã°, ãããã¯ãŒã¯ãããŒãªã©, æã ãæ¥åžžã§åºãããå ·äœçãªè«žåé¡ã«åãçµãéã«ç¹ã«éèŠãšãªãæŠå¿µã»æ¹æ³ãåŠã¶.
10.1.1 Hallã®çµå©å®ç
ããã§æ±ãçµå©åé¡ (mariage problem) ãšã¯æ¬¡ã®ãããªåé¡ã§ãã.ᅵᅵ
ᅵᅵ
çµå©åé¡
女æ§ã®æééåããã, å女æ§ã¯äœäººãã®ç·æ§ãšç¥ãåãã§ãããšãã. å šãŠã®å¥³æ§ãç¥ãåãã®ç·æ§ãšçµå©ãã§ããããã«ã«ããã«ãçµããããã«ã¯ã©ã®ãããªæ¡ä»¶ãå¿ èŠã§ããã ?
ããã§ã¯ãããªãäžè¬è«ããå ¥ãã®ã§ã¯ãªã, 次ã®è¡šã§äžããããå ·äœäŸãã°ã©ããçšããŠèå¯ããããšããã¯ãããã. ãã®è¡šã§ã¯å¥³æ§éåã {g1, g2, g3, g4}, ç·æ§éåã {b1, b2, b3, b4, b5} ãšãã.
å¥³æ§ å¥³æ§ãšç¥ãåãã®ç·æ§
g1 b1, b4, b5
g2 b1
g3 b2, b3, b4
g4 b2, b4
ãããã°ã©ãã§æãããã®ãå³ 10.231 ã§ãã. ããŠ, å®å šäºéšã°ã©ã G(V1, V2)ã«ããã, ç¹ V1ããç¹ V2
g1
g2
g3
g4
b1
b2
b3
b4
b5
å³ 10.231: 女æ§ãšãã®ç¥ãåãã®ç·æ§ãè¡šãã°ã©ã.
ãžã®å®å šãããã³ã°ããV1ãš V2ã®éšåéåã®éã®äžå¯Ÿäžå¯Ÿå¿ã§, ãã€, 察å¿ããç¹ã¯èŸºã§çµã°ããŠãããã®ãã§ãããšå®çŸ©ããã°, äžã«ãããçµå©åé¡ã¯æ¬¡ã®ããã«èšãçŽãããšãã§ãã.
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäžï¿œï¿œ
ᅵᅵ
çµå©åé¡ã®ãå®å šãããã³ã°ããçšããèšããã
G = G(V1, V2)ãäºéšã°ã©ãã®ãšã, Gã«ãã㊠V1ãã V2ãžã®å®å šãããã³ã°ãããã®ã¯ã©ã®ã
ããªãšãã ?
ãã®åé¡ã®çãã¯æ¬¡ã®å®çã«ãã£ãŠäžãããã.
Hallã®å®ççµå©åé¡ã«è§£ãããããã®å¿ èŠååæ¡ä»¶ã¯, ã©ã® k人ã®å¥³æ§ãåãã㊠k人以äžã®ç·æ§ãšç¥ãåã
ã§ããããšã§ãã.
(蚌æ)
[å¿ èŠæ§] : k人ã®å¥³æ§ã®èª°ããšç¥ãåãã®ç·æ§ãåèš k人æªæºã§ããã°å¥³æ§ãäœã£ãŠããŸãã®ã§æãã.[ååæ§] : åž°çŽæ³ã«ãã蚌æãã.ã女æ§ãm人æªæºã§ããã°å®çãæç«ããããšä»®å®ãã. ãã®ãšã, m = 1ã§ããã°, k = 1人ã®å¥³æ§ã¯ 1人ã®ç·æ§ãšç¥ãåããªã®ã§, ãã®ç·æ§ãšçµå©ããã°è¯ã. åŸã£ãŠ, æç«. m人ã®å¥³æ§ãããå Žåã«ã¯æ¬¡ã®ãã㪠2ã€ã®å Žåã«åããŠèãã.
(i) k < mãªã, ã©ã® k人ã®å¥³æ§ããšã£ãŠã, åãã㊠k + 1人ã®ç·æ§ãšç¥ãåãã®ãšãå¥³æ§ 1人ãéžã³, ç¥ãåãã®ä»»æã®ç·æ§ãšçµå©ãããã°, æ®ãmâ 1人 (m â 1 < m)ã®å¥³æ§ã¯åãããŠmâ 1人ã®ç·æ§ãšç¥ãåãã§ãã. åŸã£ãŠ, åž°çŽæ³ã®ä»®å®ãã蚌æçµãã.
(ii) k(< m)人ã®å¥³æ§ãåãããŠã¡ããã© k人ã®ç·æ§ãšç¥ãåãã®ãšã
åž°çŽæ³ã«ãã, k人ã®å¥³æ§ã¯çµå©å¯èœ. æ®ãã¯mâ k人ã§ãã. (mâ k)人ã®äžã®ã©ã® h人 (h †mâ k)ãæ®ãã® h人以äžã®ç·æ§ãšç¥ãåãã§ãã ((h+ k)人ã®å¥³æ§ã¯ (h+ k)人以äžã®ç·æ§ãšç¥ãåãã§ããã¹ããªã®ã§). åŸã£ãŠ, mâ k人ã®å¥³æ§ã«å¯ŸããŠæ¡ä»¶æç«.
以äžã«ãã蚌æçµãã.
10.1.2 暪æçè«
ãŸã, 次ã®ããã«å®çŸ©ããŠããã.
E : 空ã§ãªãæééå.F = (S1, S2, · · · , Sm) : Eã®ç©ºã§ãªãéšåéåã®æ.Fã®æšªæ : åéå Si ãã 1ã€éžãã Eã®çžç°ãªãmåã®å ã®éå.
(äŸ)E = {1, 2, 3, 4, 5, 6}, S1 = S2 = {1, 2}, S3 = S4 = {2, 3}, S5 = {1, 4, 5, 6} ãšãã. ãã®ãšã, æ F =(S1, S2, · · · , S5)ã«æšªæã¯ç¡ã. äžæ¹, F
â²= (S1, S2, S3, S5)ã«ã¯ {1, 2, 3, 4}ã®æšªæ (éšå暪æ) ããã.
10.1.3 暪æãšçµå©åé¡, åã³, Hallã®å®çãšã®é¢ä¿
ç·æ§ã®éåã E = {b1, b2, b3, b4, b5, b6} = {1, 2, 3, 4, 5, 6}ãšãã.äžæ¹, 女æ§ã®éåã F = (g1, g2, g3, g4, g5) = (S1, S2, S3, S4, S5) ãšã,
S1 = {1, 2}S2 = {1, 2}
ãã㯠222ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
S3 = {2, 3}S4 = {2, 3}S5 = {1, 4, 5, 6}
ãšããã° (å³ 10.232ãåãããŠåç §), äžããããéåæ Fã暪æãæã€ããã®å¿ èŠååæ¡ä»¶ãHallã®å®
çã§ãã.
g1
g2
g3
g4
g5
b1
b2
b3
b4
b5
b6
å³ 10.232: ããã§æšªæãš Hall ã®å®çã®é¢ä¿ãèãã, 女æ§ãšãã®ç¥ãåãã®ç·æ§ãè¡šãã°ã©ã.
10.1.4 Hallã®å®çã®å¿çšäŸ : ã©ãã³æ¹é£ï¿œ
ᅵ
ᅵ
ã©ãã³é·æ¹åœ¢
mà n (m †n) ã©ãã³é·æ¹åœ¢ : 次ã®æ§è³ªãæã€mà n è¡å M
(i) ä»»æã®è¡åèŠçŽ 㯠1 †mij †nãæºãã.(ii) ã©ã®è¡, åã³, ã©ã®åã«ãåãèŠçŽ ã¯ãªã.
(äŸ)
M =
â¡â¢â£
1 2 3 4 52 4 1 5 33 5 2 1 4
â€â¥âŠ (10.427)
ã¯ã©ãã³é·æ¹åœ¢ã§ãã.
m = nã§ãããããªã©ãã³é·æ¹åœ¢ãã©ãã³æ¹é£ãšåŒã¶ã, ã©ãã³é·æ¹åœ¢ããã©ãã³æ¹é£ãžã®æ¡å€§å¯èœæ§ã¯æ¬¡ã®å®çã§äžãããã.
å®ç 27.1M ã¯m < nãããªãmà nã©ãã³é·æ¹åœ¢ã§ãããšãã. ãã®ãšã, M ã« nâmæ¬ã®æ°ããè¡ãä»ãå ããŠã©ãã³æ¹é£ã«æ¡åŒµããããšãã§ãã.
(å ·äœçãªäœãæ¹)
E = {1, 2, 3, 4, 5}ãäžããããã©ãã³é·æ¹åœ¢M ã®è¡èŠçŽ ã®éåã§ãããšãã. F = (S1, S2, S3, S4, S5) ãšã, M ã®ç¬¬ iåã«çŸããªã Eã®èŠçŽ ã®éåã Siã§ãããã. (10.427)åŒã§äžããããã©ãã³é·æ¹åœ¢ãäŸã«ãšãã° S1, S2, · · · ,ã¯
S1 = {4, 5}
ãã㯠223ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
S2 = {1, 3}S3 = {4, 5}S4 = {2, 3}S5 = {1, 2}
ãšãªã, Fãã暪æãèŠã€ã㊠(4, 3, 5, 2, 1), (5, 1, 4, 3, 2)ãåŸãããã®ã§, ãããã©ãã³é·æ¹åœ¢ã«ä»ãå ããŠ
M =
â¡â¢â¢â¢â¢â¢â¢â£
1 2 3 4 52 4 1 5 33 5 2 1 44 3 5 2 15 1 4 3 2
â€â¥â¥â¥â¥â¥â¥âŠ
(10.428)
ãšãªã (ä»ãå ããéšåã¯å€ªåã§è¡šãããŠãã).
10.1.5 Mengerã®å®ç
ãŸãã¯åçš®å®çŸ©ãã
èŸºçŽ ãªé (edge-disjoint path) : å ±éãªèŸºãæããªã vãã wãžã®é.ç¹çŽ ãªé (vertex-disjoint path) : å ±éãªç¹ãæããªã v ãã wãžã®é.vw-éé£çµåéå : ã°ã©ã G ã®èŸºéå Eã§, vãã wãžã®ä»»æã®éã¯å¿ ã Eã®èŸºãå«ããã®.(äŸ) : å³ 10.233ã«ãã㊠E1 = {ps, qs, ty, tz}, E2 = {uw, xw, yw, zw}.vw-åé¢éå : Gã®ç¹ã®éå Vã§, vãã wãžã®ä»»æã®éã¯å¿ ã V ã®ç¹ãéããšããæ§è³ªãæ〠V .(äŸ) : å³ 10.233ã«ãã㊠V1 = {s, t},V2 = {p, q, y, z}.
G
v
q
r
p
s
t
z
y
x
u
w
å³ 10.233: ç¹çŽ ãªéã 2 æ¬ããã°ã©ã G. (ãããã®é㯠v â p â u â w, åã³, v â r â t â y â w)
ãvãã wãžã®èŸºçŽ ãªéã®æ¬æ°ã¯äœæ¬ã ?ããšããåãã«å¯Ÿããçã âMengerã®å®ç I
Mengerã®å®ç Ié£çµã°ã©ã Gã®ç°ãªã 2ç¹ vãš wãçµã¶èŸºçŽ ãªéæ°ã®æ倧å€ã¯, vw-éé£çµåéåã®èŸºæ°ã®æå°å€ã«çãã.
ãvãã wãžã®ç¹çŽ ãªéã®æ¬æ°ã¯äœæ¬ã ?ããšããåãã«å¯Ÿããçã âMengerã®å®ç II
ãã㯠224ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
Mengerã®å®ç II
é£çµã°ã©ã Gã®é£æ¥ããŠããªã 2ç¹ vãš wãçµã¶ç¹çŽ ãªéæ°ã®æ倧å€ã¯, vw-åé¢éåã®èŸºæ°ã®æå°å€ã«çãã.
(äŸ)å³ 10.234ã®ã°ã©ã Gã«å¯ŸããŠ, vw-éé£çµåéå㯠E1 = {vp, vq},E2 = {pr, qr, qs},E3 = {rw, sw} ã§ãããã, èŸºçŽ ãªéæ°ã®æå°å€ã¯ 2ã§ãã. äžæ¹, vw-åé¢éå㯠V1 = {p, q},V2 = {r, q},V3 = {r, s} ã§ãããã, ç¹çŽ ãªéæ°ã®æ倧å€ã¯ 2ã§ãã.
p
v
q s
r
w
å³ 10.234: Menger ã®å®çã確èªããäŸãšããŠçšããã°ã©ã G.
10.2 ãããã¯ãŒã¯ãããŒ
å³ 10.235ã®ãããªæåã°ã©ããèãã. ç¹ vã¯ãäŒç€Ÿãã§ãã, ç¹ wã¯ã販売åºããšãã. å蟺ã«èšãããæ°åã¯, ãã®ã«ãŒã (匧)ãééã§ããè·ç©ã®æ倧é (äŸãã°ãç®±ã®åæ°ããšèšãæããŠãè¯ã)ã§ãããšãã. ãã®ãšã, æã ã®åé¡ã¯
v
z
y
x
w
4
3
1
2
4
1 2
2
4
å³ 10.235: ããã§èããæåã°ã©ã. v ã¯ãäŒç€Ÿã㧠w ãã販売åºããè¡šããã®ãšãã. å匧ã«èšãããæ°åã¯ã容éãã§ãã.
ᅵᅵ
ᅵᅵåé¡
åã«ãŒãã®èš±å®¹éãè¶ ããªãããã«ããŠäŒç€Ÿãã販売åºã«éãããšã®ã§ããç®±ã®åæ°ã¯ããã€ã ?
ãã®åé¡ã«çããåã«ããã€ãã®å®çŸ©ãããŠããã.
ãããã¯ãŒã¯ N : éã¿ã€ãæåã°ã©ã.容é Κ(a) : å匧 aã«å²ãåœãŠãããéè² å®æ°.
outdeg(x) : xzã®åœ¢ããã匧ã®å®¹éã®ç·å.
ãã㯠225ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
indeg(x) : zxã®åœ¢ããã匧ã®å®¹éã®ç·å17 .åŸã£ãŠ, ãããã¯ãŒã¯ã®å šç¹ã«ã€ããŠã®åºæ¬¡æ°ã®ç·åã¯å ¥æ¬¡æ°ã®ç·åã«çãã.ï¿œ
ᅵ
ᅵ
ᅵ
ãã㌠(flow)
å匧 a ã«å¯Ÿãéè² å®æ° Ï(a)ãå²ãåœãŠãé¢æ° Ïã®ããšã§ãã, 次㮠2ã€ã®æ¡ä»¶ãæºãããªããã°ãªããªã.
(i) å匧 aã«å¯Ÿã㊠Ï(a) †Κ(a).(ii) vãš w以å€ã®åç¹ã«ãããŠ, åºæ¬¡æ°ãšå ¥æ¬¡æ°ãçãã.
(äŸ)
æ¡ææåè£é¡ã«ãã, å³ 10.236ã«ãããŠ
(å ¥å£ v ããåºã匧ã®ãããŒã®ç·å) = (åºå£ wãžå ¥ã匧ã®ãããŒã®ç·å)
= ãããŒã®å€ = 6 (å³ 10.236ã®å Žåã«ã¯æ倧ãããŒã«ãªã£ãŠãã)
v
z
y
x
w
3
2
1
2
0
1 0
2
4
å³ 10.236: å³ 10.235 ã®å匧ã«èšããã容éãè¶ ããªãããã«, ãã€, v,w ãé€ãåç¹ã«ãããŠå ¥æ¬¡æ°ãšåºæ¬¡æ°ãçããããããã«å匧ã«æ°åãæ¯ããšãããªã.
ᅵᅵ !ã«ãã (cut) : æåã°ã©ã Dã® vw-éé£çµåéå.
ã«ããã®å®¹é : ã«ããã®åŒ§ã®å®¹éã®ç·å.
å³ 10.235ã®ã°ã©ãã«ãããŠ, æå°ã«ãã (容éãã§ããã ãå°ããã«ãã) 㯠{xw, xz, yz, vz}, {xw, zw}ã§ãã, ãã®å®¹é㯠6ã§ãã.
æ倧ãããŒæå°ã«ããå®ç
ä»»æã®ãããã¯ãŒã¯ã«ãããŠ, æ倧ãããŒã®å€ã¯æå°ã«ããã®å®¹éã«çãã.
蚌æç¥.ããã§äŸãšããŠæ±ã£ãå³ 10.235, å³ 10.236ã«é¢ããŠã¯, äžèšã®è°è«ãã, (æ倧ãããŒ) = (æå°ã«ãã) = 6ãšãªã£ãŠãã, ãã®å®çãæãç«ã£ãŠããããšã確ããããã.
17 以å, indeg, outdeg ãããããå ¥æ¬¡æ°, åºæ¬¡æ°ãšããŠå®çŸ©ããã, ããã§ã¯èŸºã«èšãããæ°åã«ãããéã¿ä»ããã®å ¥æ¬¡æ°, åºæ¬¡æ°ã§ããããšã«æ³šæãããã.
ãã㯠226ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
10.2.1 æ倧ãããŒã®é次æ§ææ³
æåŸã«æ倧ãããŒãå ·äœçã«æ±ããããã®ã¢ã«ãŽãªãºã ãäžã€æããŠãã.ãããã¯ãŒã¯ã«ãããŠå ¥å£ vãšåºå£ wãçµã¶é pãèã, ãã®éãç¹å : v, v1, v2, · · · , vkâ1, vk,wã§ç¹å®ã
ã (å³ 10.237åç §). ãŸã, ãã®éã蟺ã§ç¹å®ããéã«ã¯èŸºã®åãããèæ ®ã, ei = (viâ1, vi) ã®ãšã, ei ã¯
v=v0
v1
v2
v3
e1
e2 e3
v k-1
vk=w
ek
å³ 10.237: ãããã¯ãŒã¯ã«ãããäžã€ã®é p. ãã®éã«ãããŠ, e1 ã¯ãæ£é ãã§ãã, e2 ã¯éé ã§ãã.
ç¹ vi, viâ1 ããã®é ã«ç¢å°ã§çµã¶. ãã®å Žåãé pã«ãã㊠ei ã¯æ£é ã§ãããšãã. äžæ¹, ei = (vi, viâ1)ã®ãšãã«ã¯ eiãç¹ viâ1, viããã®é ã«ç¢å°ã§çµã¶ããšã«ãªãã, ãã®å Žåãéé ãšåŒã¶. å³ 10.237 ã®äŸã§èšãã°, e1ãæ£é , e2 ãéé ãšããããšã«ãªã.ããŠ, ãã®ãšãå蟺 ei ã«å¯Ÿã, äœè£ (residual)ãšåŒã°ããé (泚ç®ãã蟺ã«æ²¿ã£ãŠçç®ããæ¹åãžãŸã
å¢ããããšã®ã§ãããããŒ) ãå蟺ã®å®¹é Κ(ei), åã³, çŸæç¹ã§ã®ãã㌠Ï(ei)ãçšããŠæ¬¡ã®ããã«å®çŸ©ãã.
g(ei) =
{Κ(ei)â Ï(ei) (ei ãæ£é )Ï(ei) (ei ãéé )
(10.429)
次ãã§ãã® g(ei)ãçšããŠåé pã«å¯ŸããŠã®äœè£ g(p)ã
g(p) = min1â€iâ€k
g(ei) (10.430)
ã§å®çŸ©ãã. ããã§å蟺ã«å¯ŸããŠèŠå :
Ï(ei) â Ï(ei) + g(p) (ei ãæ£é ) (10.431)
Ï(ei) â Ï(ei)â g(p) (ei ãéé ) (10.432)
é©çšããããšã«ãã, çŸæç¹ã§ã®ãã㌠Ïã g(p)ã ã倧ããªæ°ãããããŒã«å€æŽããããšãã§ãã. ã€ãŸã, eiãæ£é ã§ããã®ã§ããã°, 蟺 e1ã®å®¹éãšçŸæç¹ã§ã®ãããŒã®é pã«é¢ããæå°å€ g(p)ã®åã ãå蟺ã®ãããŒãå¢å ããããšãã§ããã, éã«, 蟺 ei ãéé ã§ããã°,ãçŸåšã®åãã®ãããŒã®æå°å€ g(p)ã®åã ã, å蟺ã®ãããŒã®å€ããå·®ãåŒãããšã«ãã, ææã®åããžã®ãããŒãå¢å ãããããšãã§ãã.
以äžããŸãšãããšæ¬¡ã®ããã«ãªã.ï¿œ
ᅵ
ᅵ
æ倧ãããŒé次æ§æã¢ã«ãŽãªãºã
1. å šãŠã®èŸº eã«å¯Ÿã㊠Ï(e) = 0 ãšçœ®ã.2. vãã wãžã®é pã§æ£ã®äœè£ g(p) > 0ãæã€ãã®ãæ¢ã, ãªããã°çµäº. ããã°æ¬¡ã® 3.ãž.3. èŠå (10.431)(10.432)ã«åŸã£ãŠçŸåšã®ãã㌠Ïãå€æŽã, 2.ãž
ãã㯠227ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
10.2.2 æ倧ãããã³ã°ãžã®é©çš
ããã§åŠãã æ倧ãããŒã®é次æ§ææ³ãçšããŠ, ååºã®æ倧ãããã³ã°ãæ±ããããšãã§ãã. ããã§ã¯ãããç°¡åã«è¿°ã¹ãŠãããã. å³ 10.238 ã®ãããªãããã¯ãŒã¯ãèãã. ããã§æ±ãããããã³ã°ã¯éå
U V
11
8
å³ 10.238: U ãš V ã®éã®æ倧ãããã³ã°ãæ±ããããã®ãããã¯ãŒã¯.
Uãš Vã®éã®æ倧ãããã³ã°ã§ãã.
ã€ãŸã, å ¥å£ vãšéå Uã«å±ããç¹ãçµã¶èŸºã®å šãŠã«å®¹é 1ã, ãããã³ã°ããšãã¹ãéå Uãšéå Vã
çµã¶å šãŠã®èŸºã«å®¹éâã, ãããŠæåŸã«éå Vãšåºå£ wãçµã¶å šãŠã®èŸºã«å®¹é 1ãå²ãæ¯ã, ãã®ãããã¯ãŒã¯ã«å¯ŸããŠé次æ§ææ³ãé©çšãã. æçµçã«åŸããããããã³ã°ãæ倧ã§ããããš, åã³, ãã®ãããã¯ãŒã¯ã§é次æ§ææ³ãçšããããšã§ææã®æ倧ãããã³ã°ãåŸãããçç±ã¯åèªãèããŠã¿ãããš.ï¿œ
ᅵ
ᅵ
ᅵ
ãäŸé¡ 13.1ã (2004幎床 æŒç¿åé¡ 13 )
å³ã®ãããªæåã°ã©ãã«é¢ããŠä»¥äžã®åãã«çãã.
vw
20
10
11
7
4
5
13
3
a
bc
d
(1)é次æ§ææ³ãçšããŠå³ã®å ¥å£ vããåºå£ w ãžè³ããããã¯ãŒã¯ã®æ倧ãããŒãæ±ãã.(2)å³ã®ãããã¯ãŒã¯ã«ãããæå°ã«ãããæ±ã, (1)ã®çµæãšæ¯èŒããããšã«ãã, æ倧ãããŒæå°ã«ããå®çãæç«ããŠãããåŠãã確ããã.
(解çäŸ)
(1)ãŸãã¯é p1ãšããŠåé¡æäžã®å³ã«ããã vâ aâ dâ wãéžã¶. é次æ§ææ³ã®ã¢ã«ãŽãªãºã ãã, æåã®ã¹ãããã§ã¯å šãŠã®èŸºã®ãããŒããŒãã«èšå®ããã®ã§
Ï(v, a) = Ï(a, d) = Ï(d,w) = 0 (10.433)
ãšãã. ãã®ãšã, p1äžã®å šãŠã®èŸºã¯æ£é ã§ãã
g(v, a) = Κ(v, a)â Ï(v, a) = 20â 0 = 20
g(a, d) = Κ(a, d)â Ï(a, d) = 11â 0 = 11
g(d,w) = Κ(d,w)â Ï(d,w) = 13â 0 = 13
ãã㯠228ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãªã®ã§, é p1ã®äœè£ã¯
g(p1) = mink=(v,a),(a,d),(d,w)
g(k) = 11 (10.434)
ãšãªã. åŸã£ãŠ, 次ã¹ãããã§ã®å蟺ã®ãããŒã¯ (10.433)(10.434)ãã
Ï(v, a) = 0 + g(p1) = 11
Ï(a, d) = 0 + g(p1) = 11
Ï(d,w) = 0 + g(p1) = 11
ã§ãã.
次ã®é p2ãšã㊠vâ bâ câ wãéžã¶. ãã® p2äžã®å šãŠã®èŸºã®ãããŒãåãã¯ãŒãã«èšå®ãããŠã
ãã¹ãã§ãããã
Ï(v, b) = Ï(b, c) = Ï(c,w) = 0 (10.435)
ã§ãã. ãããã®èŸºã¯å šãŠæ£é ã§ããã®ã§
g(v, b) = Κ(v, b)â Ï(v, b) = 10â 0 = 10
g(b, c) = Κ(b, c)â Ï(b, c) = 7â 0 = 7
g(c,w) = Κ(c,w)â Ï(c,w) = 3â 0 = 3
ãšãªã, åŸã£ãŠé p2ã®äœè£ã¯
g(p2) = mink=(v,b),(b,c),(c,w)
g(k) = 3 (10.436)
ã§ãã. åŸã£ãŠ, 次ã¹ãããã§ã®å蟺ã®ãããŒã¯ (10.435)(10.436) ãã
Ï(v, b) = 0 + g(p2) = 3
Ï(b, c) = 0 + g(p2) = 3
Ï(c,w) = 0 + g(p2) = 3
ã§ãã.
ãã®æç¹ã§å蟺ã®ãããŒãèŠãŠã¿ããš, 蟺 (a, d), åã³, (c,w)ã®ãããŒã®å€ã容éãã£ã±ãã«ãªã£ãŠãã. åŸã£ãŠ, ãã® 2ã€ã®èŸºãå«ããããªéã«é¢ããŠã¯æ£ã®äœè£ãæãããããšã¯ã§ãã, åŸã£ãŠ, ãã®å®¹éãå¢ããããšã¯ã§ããªã. ãã®ããšãèæ ®ã«å ¥ã, ãã€, å ¥å£ vããåºå£ wã«è³ãéãéžã¶ãšãªã
ãšãã㯠vâ aâ câ dâ w, åã³, vâ bâ câ dâ wãããªã. åè ã p3, åŸè ã p4ãšããã.ãŸã p3ã«å¯ŸããŠ, ãã®æç¹ã§ã®å蟺ã®ãããŒã¯
Ï(v, a) = 11
Ï(a, c) = 0
Ï(c, d) = 0
Ï(d,w) = 11
ã§ãã. (a, c), (c, d)ã¯éé ã§ããããšã«æ³šæããŠ
g(v, a) = Κ(v, a)â Ï(v, a) = 20â 11 = 9
g(a, c) = Ï(a, c) = 0
g(c, d) = Ï(c, d) = 0
g(d,w) = Κ(d,w)â Ï(d,w) = 13â 11 = 2
ãã㯠229ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãšãªãã®ã§, ãã®é p3ã®äœè£ã¯
g(p3) = mink=(v,a),(a,c),(c,d),(d,w)
g(k) = 0
åŸã£ãŠ, å蟺ã®ãããŒã¯ãã®æäœã®ååŸã§å€ããã
Ï(v, a) = 11
Ï(a, c) = 0
Ï(c, d) = 0
Ï(d,w) = 11
ã§ãã.æåŸã«é p4ã«ã€ããŠ. ãã®æç¹ã§ã®å蟺ã®ãããŒå€ã¯
Ï(v, b) = 3
Ï(b, c) = 3
Ï(c, d) = 0
Ï(d,w) = 11
ã§ãã, (c, d)ãéé ã§ããããšãèæ ®ãããš
g(v, b) = Κ(v, b)â Ï(v, b) = 10â 3 = 7
g(b, c) = Κ(b, c)â Ï(b, c) = 7â 3 = 4
g(c, d) = Ï(c, d) = 0
g(d,w) = Κ(d,w)â Ï(d,w) = 13â 11 = 2
ãšãªã. ãã£ãŠé p4ã®äœè£ã¯
g(p4) = mink=(v,b),(b,c),(c,d),(d,w)
g(k) = 0
ãªã®ã§, ãã®æäœã§å蟺ã®ãããŒã¯å€åãã
Ï(v, b) = 3
Ï(b, c) = 3
Ï(c, d) = 0
Ï(d,w) = 11
ã®ãŸãŸã§ãã. 以äžããŸãšãããš, æçµçã«åŸãããæ倧ãããŒã®å€ã¯ 11 + 3 = 14ã§ãã, ãã®ãšãã®å蟺ã®ãããŒã¯å³ 10.239ã®ããã«ãªã.
(2)å³ 10.239ã®å€ªãç¢å°ã®ãããªã«ãããèãããš,ãã®ã«ãã㧠vãšwã¯åé¢ã,ã«ãã容é㯠11â4+7 =14ãšãªã, ãã㯠(1)ã§æ±ããæ倧ãããŒã®å€ãšäžèŽãã. åŸã£ãŠ, 確ãã«æ倧ãããŒæå°ã«ããå®çãæºãããŠãã.
ãã㯠230ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
vw
11
3
11
3
0
0
11
3
a
bc
d
(20)
(10)
(7)
(11)
(4)
(5)
(13)
(3)
å³ 10.239: é次æ§ææ³ãé©çšããçµæ, å蟺ã«å²ãåœãŠããããããŒã®å€. æ¬åŒ§å ã¯å蟺ã®å®¹éãè¡šã. 倪ãç¢å°ã§èšãããã«ããã®å®¹éã¯æå°ã§ãã, 11 â 4 + 7 = 14 ã§ãã, ããã¯ãã¡ããæ倧ãã㌠11 + 3 = 14 ãšäžèŽãã.
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ããäŸé¡ 13.2ãã (2005, 2006幎床 æŒç¿åé¡ 13 )
å³ã®ãããã¯ãŒã¯ãèãã.
a
c
wv b
4
5
1
65
4
2
2
1
(1)ãã®ãããã¯ãŒã¯ã®ã«ãããå šãŠåæã, æå°ã«ãããèŠã€ãã.(2)æ倧ãããŒãèŠã€ããŠ, æ倧ãããŒæå°ã«ããå®çã確èªãã.
(解çäŸ)
(1)äžãããããããã¯ãŒã¯ã®ã«ããããã³ãã®å®¹éãåæã, æå°ã«ãããæ±ãããš
{aw,bw,cw} 容é 8 (â» æå°ã«ãã)
{cv,bc,cw} 容é 8 (â» æå°ã«ãã)
{av,bv,cv} 容é 10
{av,ab,aw} 容é 17
{av,bv,bc,cw} 容é 8 (â» æå°ã«ãã)
{aw,bw,bc,cv} 容é 12
{ab,bv,bc,bw} 容é 17
{aw,ab,bv,cv} 容é 19
{av,ab,bw,cw} 容é 21
{av,bv,bc,bw,aw} 容é 12
{aw,ab,bv,bc,cw} 容é 17
{cv,bv,ab,bw,cw} 容é 23
ãã㯠231ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
{av,ab,bw,bc,cv} 容é 25
ãšãªã.(2)é次æ§ææ³ã«ããæ±ããŠã¿ã. ãŸã㯠p1 ãšã㊠v â a â w ãéžã¶ãš, ã¯ããå šãŠã®èŸºã®ãããŒããŒãã«ããã®ã§
Ï(v, a) = Ï(a,w) = 0 (10.437)
ãšãªã. ãã®ãšã, p1äžã®å šãŠã®èŸºã¯æ£é ãªã®ã§, å蟺ã®å®¹éã Ί(u, v)ãšãããš
g(v, a) = Ί(v, a)â Ï(v, a) = 4â 0 = 4 (10.438)
g(a,w) = Ί(a,w)â Ï(a,w) = 2â 0 = 2 (10.439)
ãšãªãã®ã§, é p1ã®äœè£ g(p1)ã¯
g(p1) = mink=(v,a),(a,w)
g(k) = 2 (10.440)
ãšãªã. åŸã£ãŠ, å蟺ã®ãããŒã¯
Ï(sfv, a) = 0 + g(p1) = 2 (10.441)
Ï(a,w) = 0 + g(p1) = 2 (10.442)
ãšæŽæ°ããã. åæ§ã«ããŠ, é p2, p3ã« v â b â w, v â c â wãéžã¶ãš, p2, p3 äžã®å šãŠã®èŸºã¯æ£é
ãªã®ã§, ããããã®éã®äœè£ã¯ g(p1) = 1, g(p2) = 2ãšãªã, å蟺ã®ãããŒã¯
Ï(v, b) = 0 + g(p2) = 1 (10.443)
Ï(b,w) = 0 + g(p2) = 1 (10.444)
Ï(v, c) = 0 + g(p3) = 2 (10.445)
Ï(c,w) = 0 + g(p3) = 2 (10.446)
ãšãªã. ãã®æç¹ã§èŸº vb, aw, cwã®ãããŒã¯å®¹éãã£ã±ãã§ãã, ãã® 3蟺ãå«ãéã«é¢ããŠã¯ãããŒã®å€ãå¢ããããšãã§ããªã. ãŸã, éã«èŸº aw ãå«ããããªãããšãã, 蟺 ba ãæ£é ã«é¡ãããš
ãã§ãã, éé ã«ããé¡ããªã. ããã, 蟺 baã®ãããŒã®å€ã¯ãŒãã§ãã, éé ã«é¡ã£ãŠããã¯ããããŒã®å€ãå¢ããããšã¯ã§ããªãã®ã§, 蟺 baãéã«å«ãŸãªãããšã«ãã. ãããããšèããããéã¯vâ aâ bâ w, vâ câ bâ wã§ãã. ããããã p4, p5ãšããã. ãŸã, é p4ã«é¢ããŠ, å蟺ã¯æ£é ãªã®ã§
g(v, a) = Ί(v, a)â Ï(v, a) = 4â 2 = 2 (10.447)
g(a, b) = Ί(a, b)â Ï(a, b) = 5â 0 = 5 (10.448)
g(b,w) = Ί(b,w)â Ï(b,w) = 4â 1 = 3 (10.449)
ã§ãã, é p4ã®äœè£ã¯
g(p4) = mink=(v,a),(a,b),(b,w)
g(k) = 2 (10.450)
ã§ãã. åŸã£ãŠ, å蟺ã®ãããŒã¯
Ï(v, a) = 2 + g(p4) = 4 (10.451)
Ï(a, b) = 0 + g(p4) = 2 (10.452)
Ï(b,w) = 1 + g(p4) = 3 (10.453)
ãã㯠232ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãšæŽæ°ããã. 次ã«é p5ã«é¢ããŠã¯å蟺ãæ£é ãªã®ã§
g(v, c) = Ί(v, c)â Ï(v, c) = 5â 2 = 3 (10.454)
g(c, b) = Ί(c, b)â Ï(c, b) = 1â 0 = 1 (10.455)
g(b,w) = Ί(b,w)â Ï(b,w) = 4â 3 = 1 (10.456)
ã§ãã, é p5ã®äœè£ã¯
g(p5) = mink=(v,c),(c,b),(b,w)
g(k) = 1 (10.457)
ãšãªã. åŸã£ãŠ, å蟺ã®ãããŒã¯
Ï(v, c) = 2 + g(p5) = 3 (10.458)
Ï(c, b) = 0 + g(p5) = 1 (10.459)
Ï(b,w) = 3 + g(p5) = 4 (10.460)
ãšæŽæ°ããã. æçµçãªå蟺ã®ãããŒã¯å³ã®ããã«ãªã, æ倧ãããŒã®å€ã¯ 4 + 1 + 3 = 8ã§ãã, (1)ã®çµæãšäœµãããšç¢ºãã«æ倧ãããŒæå°ã«ããå®çãæºãããŠãã.
ãã㯠233ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
å³ 10.240: äŸå¹Ž 7 æã¯äºäžåºåŒµã®ãã 1 åäŒè¬ãå ¥ããŸãã. 2007 幎ã¯ã€ã¿ãªã¢.
ãã㯠234ããŒãžç®
235
2004幎床 ææ«è©Šéš (æ å ±å·¥åŠç§ 3幎ç/é»åå·¥åŠç§ 4幎ç)
å¹³æ16幎床 ã°ã©ãçè« ææ«è©Šéšåé¡ (9/13 å®æœ ãåºé¡è : äºäž çŽäž)
⻠泚æäºé : åé¡çšçŽã¯ 2ããŒãžãã, 倧åèš 4é¡ã§ãã (50ç¹æºç¹). 解ççšçŽ, èšç® (äžæžã)çšçŽã¯å1æé åžãã. 解ççšçŽã«ã¯æ°å, åŠç§åŠççªå·ãèšå ¥ã, è£é¢ã䜿ãéã«ã¯ãè£ã«ç¶ãããšèšå ¥ããããš.è©Šéšéå§åŸ 30åéã¯é宀ã§ããªã. ãŸã, äžåºŠé宀ããå Žåã«ã¯åå ¥å®€ã§ããªãã®ã§æ³šæããããã«.
åé¡ 1 (é ç¹ 10ç¹) (ããŒã¯ãŒã : é£æ¥è¡å, æ¥ç¶è¡å)
(1)å³ 11.241ã«äžããã°ã©ãã®é£æ¥è¡åA, åã³, æ¥ç¶è¡åM ãæ±ãã (4ç¹).
1
5 2
34
1 2
3
4 5
6
7
å³ 11.241: åé¡ 1 (1) ã®ã°ã©ã.
(2)é£æ¥è¡åã
A =
ââââââââ
0 1 1 2 01 0 0 0 11 0 0 1 12 0 1 0 00 1 1 0 0
ââââââââ
ã§äžããããã°ã©ããå³ç€ºãã (3ç¹).(3)ã°ã©ã Gã«ã«ãŒããç¡ããšã, 次ã®ããšã«é¢ããŠãããããšãç°¡æœã«è¿°ã¹ã (3ç¹).
(i) Gã®é£æ¥è¡åã®ä»»æã®è¡, ãŸãã¯, åã®èŠçŽ ã®å(ii) Gã®æ¥ç¶è¡åã®ä»»æã®è¡ã®èŠçŽ ã®å
(iii) Gã®æ¥ç¶è¡åã®ä»»æã®åã®èŠçŽ ã®å
åé¡ 2 (é ç¹ 10ç¹) (ããŒã¯ãŒã : ãªã€ã©ãŒã»ã°ã©ã, ããã«ãã³ã»ã°ã©ã, å®å šã°ã©ã, å®å šäºéšã°ã©ã)
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
(1)ãªã€ã©ãŒã»ã°ã©ã, åãªã€ã©ãŒã»ã°ã©ããšã¯ã©ã®ãããªã°ã©ãã, ããããç°¡æœã«èª¬æãã. ãŸã, å®å šã°ã©ã K5ã¯ãªã€ã©ãŒã»ã°ã©ã, åãªã€ã©ãŒã»ã°ã©ã, ãã®ã©ã¡ãã§ããªãã°ã©ãã®ãã¡ã®ã©ãã§ããã, çç±ãšãšãã«çãã (5ç¹).
(2)ããã«ãã³ã»ã°ã©ã, åããã«ãã³ã»ã°ã©ããšã¯ã©ã®ãããªã°ã©ãã, ç°¡æœã«èª¬æãã. ãŸã, å®å šäºéšã°ã©ã K2,3ã¯ããã«ãã³ã»ã°ã©ã, åããã«ãã³ã»ã°ã©ã, ãã®ã©ã¡ãã§ããªãã°ã©ãã®ãã¡ã®ã©ãã§ããã, çç±ãšãšãã«çãã (5ç¹).
åé¡ 3 (é ç¹ 10ç¹) (ããŒã¯ãŒã : ã©ãã«ä»ãæš, æšã®æ°ãäžã, ã±ã€ãªãŒã®å®ç)
ããå®ããããç¹ã®æ¬¡æ°ã kã§ãããã㪠nåã®ç¹ãããªãã©ãã«ä»ãæšã®ç·æ° T (n, k)ã¯
T (n, k) = nâ2Ckâ1 (nâ 1)nâkâ1
ã§äžãããããšãã. ãã®ãšã以äžã®åãã«çãã.
(1) nåã®ç¹ãããªãæšã§, äžããããç¹ã端ç¹ã«ãªã£ãŠãããã®ã®ç·æ°ãæ±ãã (5ç¹).(2) nåã®ç¹ãããªãæšã®, äžããããç¹ã端ç¹ãšãªã確ç㯠nã倧ãããªãã«ã€ã, ãã極éå€ã«è¿ã¥ããšãã. ãã®æ¥µéå€ãæ±ãã (5ç¹).
åé¡ 4 (é ç¹ 20ç¹) (ããŒã¯ãŒã : ç¹åœ©è², 圩è²å€é åŒ, 蟺ã®çž®çŽ, æ°åŠçåž°çŽæ³)
GãåçŽã°ã©ããšã, Gãã蟺 eãé€å»ããŠåŸãããã°ã©ãã G-e, çž®çŽããŠåŸãããã°ã©ãã G\e ãšãããš, Gã®åœ©è²å€é åŒ PG(k)ã¯æ¬¡ã®ããã«æžãããšãã§ãã.
PG(k) = PGâe(k)â PG\e(k)
ãã®ããšããµãŸããŠä»¥äžã®åãã«çãã.
(1)å³ 11.242ã®ã°ã©ã Gã«å¯ŸããŠ, G-e, G\e ãããããå³ç€ºãã (5ç¹).
e
G
å³ 11.242: åé¡ 4 (1)(2) ã®ã°ã©ã G.
(2)ã°ã©ã Gã®åœ©è²å€é åŒã kã®é¢æ°ãšããŠæ±ãã (5ç¹).(3)ç¹æ° n, 蟺æ°mã®åçŽã°ã©ã Gã«å¯Ÿã (⻠泚 : ããã¯å³ 2.21ã®ã°ã©ã Gã«éãã, äžè¬ã®åçŽã°ã©ã
Gã«å¯ŸããŠ, ãšããæå³ã§ãã), 蟺æ°mã«é¢ããæ°åŠçåž°çŽæ³ã«ãã, PG(k)ã® knâ1ã®ä¿æ°ã¯âmã§ããããšã蚌æãã (10ç¹).
ãã㯠236ããŒãžç®
237
2004幎床 ææ«è©Šéšè§£ç (æ å ±å·¥åŠç§ 3幎ç/é»åå·¥åŠç§ 4幎ç)
å¹³æ16幎床 ã°ã©ãçè« ææ«è©Šéšè§£ç (9/13 å®æœ ã解çäœæ : äºäž çŽäž)
â» æ¡ç¹åºæº : ååé¡ã®é ç¹ã¯åé¡çšçŽã«èšããéã. 以äžã§ã¯å€ªåã§æžãããç¹æ°ã®ãã¡, ããã©ã¹ (ïŒ)äœç¹ããšæžããããã®ãéšåç¹, ããã€ãã¹ (ïŒ)äœç¹ããšæžããããã®ãæžç¹ã§ãã. ããã倪åã§ã®èšå ¥ãç¡ããã®ã¯ãã¹ãŠå®å šãªæ£è§£ã®ã¿æå¹. ãªã, ãã以å€ã«ãéšåç¹ãäžããå Žåããã.
åé¡ 1 (é ç¹ 10ç¹)
(1)é£æ¥è¡åA, æ¥ç¶è¡åM ã¯ä»¥äžã®éã (å 2ç¹).
A =
ââââââââ
0 1 0 0 11 0 1 0 10 1 0 2 00 0 2 0 11 1 0 1 0
ââââââââ , M =
ââââââââ
1 1 0 0 0 0 00 1 1 0 1 0 00 0 0 0 1 1 10 0 0 1 0 1 11 0 1 1 0 0 0
ââââââââ
(2)åé¡æã«äžããããé£æ¥è¡åãæã€ã°ã©ããæããšå³ 12.243ã®ããã«ãªã (⻠泚 : ãã®ã°ã©ããšå®å šã«äžèŽããªããŠãå圢ãªã°ã©ãã§ããã°æ£è§£).
1
4
3
2
5
å³ 12.243: åé¡ 1 (2) ã®æ£è§£ã°ã©ã.
(3)(i) ãé£æ¥è¡åã®ç¬¬ iè¡, ãããã¯, 第 iåã®èŠçŽ åã¯ç¹ iã«æ¥ç¶ãã蟺ã®æ°ãè¡šã.ã(1ç¹)
(ii) ãæ¥ç¶è¡åã®ç¬¬ iè¡ã®èŠçŽ åã¯ç¹ iã«æ¥ç¶ãã蟺ã®æ¬æ°ãè¡šã.ã (1ç¹)(iii) ãæ¥ç¶è¡åã®ç¬¬ iåã®èŠçŽ åã¯èŸº iã®äž¡ç«¯ã®ç¹ã®æ°ãè¡šã, å¿ ã 2ãšãªã.ã (1ç¹)
åé¡ 2 (é ç¹ 10ç¹)
(1)ãªã€ã©ãŒã»ã°ã©ã : å蟺ãã¡ããã© 1åãã€éãéããå°éãããã°ã©ã (1ç¹).åãªã€ã©ãŒã»ã°ã©ã : å蟺ãã¡ããã© 1åãã€éãå°éãããã°ã©ã (1ç¹).
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãŸã, å®å šã°ã©ã K5ã®å šãŠã®ç¹ã®æ¬¡æ°ã¯ 4ã§å¶æ°ã§ããã®ã§, ãªã€ã©ãŒã®å®çãã K5ã¯ãªã€ã©ãŒã»ã°
ã©ãã§ãããšçµè«ã¥ãããã. (⻠泚 : ãŸãã¯, å³ 12.244ã®ããã«å ·äœçã«éãããªã€ã©ãŒå°éã瀺ããŠãæ£è§£) (3ç¹, å®å šã°ã©ã K5ãã©ã®ãããªã°ã©ãã§ããã, ãæžããŠããã° +1ç¹).
1
2
3
4
5
6
7
8
9
10
å³ 12.244: å®å šã°ã©ã K5. çªå·é ã«åãã°, éãããªã€ã©ãŒå°éãåŸããã.
(2)ããã«ãã³ã»ã°ã©ã : åç¹ãã¡ããã© 1åãã€éãéããå°éãããã°ã©ã (1ç¹).åããã«ãã³ã»ã°ã©ã : åç¹ãã¡ããã© 1åãã€éãå°éã®ããã°ã©ã (1ç¹).ãŸã, å®å š 2éšã°ã©ãK2,3ã¯äŸãã°, å³ 12.245ã®ãããªç¹ã®é ã§åãã°å šãŠã®ç¹ã 1åãã€éãã, å¿ ãåºçºç¹ä»¥å€ã®ç¹ã§çµããã®ã§åããã«ãã³ã»ã°ã©ãã§ãã (3ç¹, å®å šäºéšã°ã©ã K2,3 ãã©ã®ãã
ãªã°ã©ãã§ããã, ãæžããŠããã°+1ç¹).
1
2
3
4
5
å³ 12.245: å®å šäºéšã°ã©ã K2,3. çªå·é ã«åãã°, ããã«ãã³å°éãåŸãããã, ããã¯éããªã.
åé¡ 3 (é ç¹ 10ç¹)
(1)端ç¹ã§ããã°, k = 1ã§ãããã (ããã«æ°ã¥ã㊠+1ç¹), æ±ããç·æ°ã¯
T (n, 1) = nâ2C0 (nâ 1)nâ2 = (nâ 1)nâ2
ã§ãã.(2) nåã®ã©ãã«ä»ãã°ã©ãã®ç·æ°ã¯
nâ1âk=1
T (n, k) =nâ1âk=1
nâ2Ckâ1(nâ 1)nâkâ1 =nâ1âk=1
nâ2Ckâ1(nâ 1)(nâ2)â(kâ1)
=nâ2âK=0
nâ2CK(nâ 1)(nâ2)âK · 1K = (nâ 1 + 1)nâ2 = nnâ2
ãã㯠238ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ã§ãããã (⻠泚 : ãã±ã€ãªãŒã®å®çãã nnâ2ããšããŠããã), äžããããç¹ã端ç¹ãšãªã確çã¯
(nâ 1)nâ2
nnâ2=
(1â 1
n
)nâ2
â 1e
(nââ)
ãšãªãã®ã§, æ±ãã極éå€ã¯ eâ1 ã§ãã. ãã ã, eã¯èªç¶å¯Ÿæ°ã®åºã§ãã.
åé¡ 4 (é ç¹ 20ç¹)
(1) G-e (2ç¹), G\e (3ç¹) ãæããšå³ 12.246ã®ããã«ãªã.
G - e G \ e
å³ 12.246: åé¡æã«äžããããã°ã©ã G ã«é¢ããã°ã©ã G-eãšã°ã©ã G\e.
(2)åé¡æã«äžããããé¢ä¿åŒ, åã³, (1)ã®çµæãçšãããš
PG(k) = PGâe(k)â PG\e(k)
= k(k â 1)3 â k(k â 1)(k â 2) = k4 â 4k3 + 7k3 â 3k
ãåŸããã.(3)ãŸã, 蟺æ°ã 1 ã®ãšã (n = 2), 圩è²å€é åŒã¯çŽã¡ã«, PG(k) = k(k â 1) = k2 â k ãšãªããã,
knâ1 = k2â1 = kã®ä¿æ°ã¯ âm = â1ãšãªã, 確ãã«é¡æãæç«. åŸã£ãŠ, èªç¶æ°m,nã«å¯ŸããŠãç¹
æ° n, 蟺æ°mã®ãšã圩è²å€é åŒ PG(k)ã® knâ1ã®ä¿æ°ãâmã§ãã (*)ããšä»®å®ãã (m = 1ã®ãšãã®åå³, åã³, ãã®ä»®å®ãæžããŠã㊠+3ç¹).ãã®ãšã, Gã®èŸºæ°ã 1æ¬å¢ãããŠm+ 1, ç¹æ°ã¯ nã§äžããããå Žåã® G-e, åã³, G\eã®èŸºæ°ãšç¹æ°ã®é¢ä¿ãè¡šã«ããŠã¿ããš
ã°ã©ã G G-e G\eèŸºæ° m+ 1 m m
ç¹æ° n n nâ 1
ãåŸããã (ãã®çš®ã®å¯Ÿå¿è¡šãæžããŠã㊠+2ç¹).ãããªã nâ 1ç¹ãããªãã°ã©ãã«é¢ããŠã, ãã®æ倧次æ°é knâ1 ã®ä¿æ°ã¯åžžã« 1ã§ããããšãš, åé¡æã«äžããããé¢ä¿åŒ, åã³, åž°çŽæ³ã®ä»®å® (*)ãçšãããš, ç¹æ° n, 蟺æ°mã®åçŽã°ã©ã Gã®åœ©è²
å€é åŒã«ããã knâ1 ã®é ã¯äžã®è¡šã«åºã¥ã
âmknâ1 (G-eããã®å¯äž)â knâ1 (G\eããã®å¯äž) = â(m+ 1) knâ1
ãšãªãã®ã§m+ 1ã®ãšãã«ãé¡ææç«. åŸã£ãŠ, ä»»æã®m ⥠1ã®æŽæ°mã«å¯ŸããŠé¡æãæãç«ã€ããš
ãèšãã (蚌æçµãã).
#泚 : åé¡æã«ã¯ãmã«é¢ããåž°çŽæ³ãçšããŠããšæ瀺ããã, åž°çŽæ³ä»¥å€ã§ã®èšŒæãè©Šã¿ãå Žå,ãããè«ççã«æ£ããå Žåã«éã, ããçžå¿ã®éšåç¹ãäžããå Žåããã.
ãã㯠239ããŒãžç®
241
2005幎床 ææ«è©Šéš (æ å ±å·¥åŠç§ 3幎ç/é»åå·¥åŠç§ 4幎ç)
å¹³æ17幎床 ã°ã©ãçè« ææ«è©Šéšåé¡ (9/16 å®æœ ãåºé¡è : äºäž çŽäž)
⻠泚æäºé : åé¡çšçŽã¯ 2ããŒãžãã, 倧åèš 4é¡ã§ãã (50ç¹æºç¹). 解ççšçŽ, èšç® (äžæžã)çšçŽã¯å1æé åžãã. 解ççšçŽã«ã¯æ°å, åŠç§åŠççªå·ãèšå ¥ã, è£é¢ã䜿ãéã«ã¯ãè£ã«ç¶ãããšèšå ¥ããããš.è©Šéšéå§åŸ 30åéã¯é宀ã§ããªã. ãŸã, äžåºŠé宀ããå Žåã«ã¯åå ¥å®€ã§ããªãã®ã§æ³šæããããã«.
åé¡ 1 (é ç¹ 10ç¹) (ããŒã¯ãŒã : é£æ¥è¡å, æ¥ç¶è¡å)
(1)å³ 13.247ã«äžããã°ã©ãã®é£æ¥è¡åA, åã³, æ¥ç¶è¡åM ãæ±ãã (4ç¹).
1
5 2
34
1 2
3
4 5
6
7
å³ 13.247: åé¡ 1 (1) ã®ã°ã©ã.
(2)é£æ¥è¡åã
A =
ââââââââ
0 1 1 2 01 0 0 0 11 0 0 1 12 0 1 0 00 1 1 0 0
ââââââââ
ã§äžããããã°ã©ããå³ç€ºãã (3ç¹).(3)ã°ã©ã Gã«ã«ãŒããç¡ããšã, 次ã®ããšã«é¢ããŠãããããšãç°¡æœã«è¿°ã¹ã (3ç¹).
(i) Gã®é£æ¥è¡åã®ä»»æã®è¡, ãŸãã¯, åã®èŠçŽ ã®å(ii) Gã®æ¥ç¶è¡åã®ä»»æã®è¡ã®èŠçŽ ã®å
(iii) Gã®æ¥ç¶è¡åã®ä»»æã®åã®èŠçŽ ã®å
åé¡ 2 (é ç¹ 10ç¹) (ããŒã¯ãŒã : æšãšãã®æ°ãäžã)
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
å³ 13.248ã®ããã« 1ç¹ãã kæ¬ã®æãåºã, ãã® kæ¬ã®æããããã« kæ¬ã®æãåºããšããæäœã nåç¹°
ãè¿ããŠã§ããæšã Tk(n)ãšåä»ããã. (泚 : nãšèšããšæ®éã¯ã°ã©ãã®ç¹ã®æ°ã瀺ããŸãã, ããã§ã¯ãæäœãã®åæ°ã§ããããšã«æ³šæ. å³ 13.248ã®äŸã¯ T3(2)ã§ãã.) ãã®ãšã次ã®åãã«çãã.
T 3 (2)
å³ 13.248: ããã§è¿°ã¹ããæäœãã«ãã£ãŠäœãããæš T3(2).
(1) T3(n)ã«å«ãŸããç¹ã®ç·æ° S3(n)ãæ±ãã. ãŸã, T3(n)ã®ç«¯ç¹ã®ç·æ°ã Q3(n)ãæ±ã, æ¯ P3(n) =Q3(n)/S3(n)ã«å¯Ÿã, 極éå€ :
p3 = limnââP3(n)
ãèšç®ãã (5ç¹).
(2) (1)ãåèã«ããŠ, ä»»æã®èªç¶æ°K ã«å¯Ÿã㊠PK(n)ãèšç®ã, nã«é¢ãã極éå€ :
pK = limnââPK(n)
ãæ±ã, ããã«K ã«é¢ãã極éå€ : pâ = limKââ pK ãèšç®ãã (5ç¹).
åé¡ 3 (é ç¹ 15ç¹) (ããŒã¯ãŒã : å¹³é¢ã°ã©ã, ãªã€ã©ãŒã®å ¬åŒ)
ã°ã©ã G (ç¹ã®æ° : n ⥠4) ãäžè§åœ¢ã®ã¿ãå«ãå¹³é¢ã°ã©ãã§ãããšãã. Gã«å«ãŸããæ¬¡æ° kã®ç¹ã®åæ°
ã nk ãšãããšã, 以äžã®åãã«çãã.
(1) Gã®èŸºæ°mãm = 3nâ 6 ã§äžããããããšã瀺ã (5ç¹).(2)次ã®é¢ä¿åŒ : 3n3 + 2n4 + n5 â n7 â 2n8 â · · · = 12 ãæãç«ã€ããšã瀺ã (5ç¹).(3) Gã¯æ¬¡æ° 5以äžã®ç¹ã 4ã€ä»¥äžå«ãããšã瀺ã (5ç¹).
åé¡ 4 (é ç¹ 15ç¹) (ããŒã¯ãŒã : ããŒã¿ãŒã¹ã³ã»ã°ã©ã, 蟺圩è²ãšåœ©è²ææ°, ããã«ãã³ã»ã°ã©ã)
(1)ããŒã¿ãŒã¹ã³ã»ã°ã©ããæã (2ç¹).(2) (1)ã§æ±ããããŒã¿ãŒã¹ã³ã»ã°ã©ãã®èŸºåœ©è²ãèãããšã, ãã®åœ©è²ææ°ãæ±ãã (3ç¹).(3)ä»»æã®ã°ã©ã Gã 3次ã®ããã«ãã³ã»ã°ã©ãã§ããã°, ãã®åœ©è²ææ°ã¯ 3ã§ããããšã瀺ã (5ç¹).(4) (2)(3)ã®çµæãçšããããšã«ãã, ããŒã¿ãŒã¹ã³ã»ã°ã©ãã¯ããã«ãã³ã»ã°ã©ããåŠããå€å®ãã (å€å®çç±ãæèšããããš) (5ç¹).
ãã㯠242ããŒãžç®
243
2005幎床 ææ«è©Šéšè§£ç (æ å ±å·¥åŠç§ 3幎ç/é»åå·¥åŠç§ 4幎ç)
å¹³æ17幎床 ã°ã©ãçè« ææ«è©Šéšè§£ç (9/16 å®æœ ã解çäœæ : äºäž çŽäž)
â» æ¡ç¹åºæº : ååé¡ã®é ç¹ã¯åé¡çšçŽã«èšããéã. 以äžã§ã¯å€ªåã§æžãããç¹æ°ã®ãã¡, ããã©ã¹ (ïŒ)äœç¹ããšæžããããã®ãéšåç¹, ããã€ãã¹ (ïŒ)äœç¹ããšæžããããã®ãæžç¹ã§ãã. ããã倪åã§ã®èšå ¥ãç¡ããã®ã¯ãã¹ãŠå®å šãªæ£è§£ã®ã¿æå¹. ãªã, ãã以å€ã«ãéšåç¹ãäžããå Žåããã.
åé¡ 1 (é ç¹ 10ç¹)
(1)é£æ¥è¡åA, æ¥ç¶è¡åM ã¯ä»¥äžã®éã (å 2ç¹).
A =
ââââââââ
0 1 0 0 11 0 1 0 10 1 0 2 00 0 2 0 11 1 0 1 0
ââââââââ , M =
ââââââââ
1 1 0 0 0 0 00 1 1 0 1 0 00 0 0 0 1 1 10 0 0 1 0 1 11 0 1 1 0 0 0
ââââââââ
(2)åé¡æã«äžããããé£æ¥è¡åãæã€ã°ã©ããæããšå³ 14.249ã®ããã«ãªã (⻠泚 : ãã®ã°ã©ããšå®å šã«äžèŽããªããŠãå圢ãªã°ã©ãã§ããã°æ£è§£).
1
4
3
2
5
å³ 14.249: åé¡ 1 (2) ã®æ£è§£ã°ã©ã.
(3)(i) ãé£æ¥è¡åã®ç¬¬ iè¡, ãããã¯, 第 iåã®èŠçŽ åã¯ç¹ iã«æ¥ç¶ãã蟺ã®æ°ãè¡šã.ã(1ç¹)
(ii) ãæ¥ç¶è¡åã®ç¬¬ iè¡ã®èŠçŽ åã¯ç¹ iã«æ¥ç¶ãã蟺ã®æ¬æ°ãè¡šã.ã (1ç¹)(iii) ãæ¥ç¶è¡åã®ç¬¬ iåã®èŠçŽ åã¯èŸº iã®äž¡ç«¯ã®ç¹ã®æ°ãè¡šã, å¿ ã 2ãšãªã.ã (1ç¹)
åé¡ 2 (é ç¹ 10ç¹)
(1)æããã«, S3(n)ã¯åé 1, å ¬æ¯ 3ã®çæ¯æ°åã®ç¬¬ né ãŸã§ã®åã§ãããã
S3(n) = 1 + 3 + 32 + · · ·+ 3n =3n+1 â 1
3(14.461)
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ã§ãã. äžæ¹, T3(n)ã®ç«¯ç¹ã®ç·æ° Q3(n)㯠T3(n)ã®äœãæ¹ããæããã« Q3(n) = 3n ã§ããã®ã§, ãããã®æ¯ P3(n) = Q3(n)/S3(n)ã¯
P3(n) =2 · 3n
3n+1 â 1(14.462)
ã§ãã, åé¡ã®æ¥µéå€ã¯
p3 = limnââP3(n) =
23
(14.463)
ãšæ±ãŸã (S3(n), Q3(n)ã®ããããäžæ¹ã ãæ£è§£ã§+1ç¹).
(2) k = K ã®å Žåã«ã¯
SK(n) =Kn+1 â 1K â 1
, QK(n) = Kn, PK(n) =(K â 1)Kn
Kn+1 â 1(14.464)
ãšãªãã®ã§ (SK(n), QK(n)ã®ããããäžæ¹ã ãæ£è§£ã§ +1ç¹), PK(n)ã«é¢ã㊠n â âã®æ¥µéããšããš
pK = limnââPK(n) =
K â 1K
(14.465)
ãåŸããã. ããã«, ãã®ç¢ºçã§K â âã®æ¥µéããšãã° pKââ = 1 ãšãªã (ãã®æ¥µéå€ãå¿ããŠããã â1ç¹).
åé¡ 3 (é ç¹ 15ç¹)
(1)å šãŠã®èŸºã¯ 3æ¬ã®èŸºã§å²ãŸããŠãã, å šãŠã®èŸºã¯ 2ã€ã®é¢ã®å¢çãšãªã£ãŠããã®ã§, é¢æ° f , 蟺æ°mã®
éã«ã¯
3f = 2m (14.466)
ãæãç«ã€ (ãã®é¢ä¿ã«æ°ã¥ã㊠+1ç¹). ãããšãªã€ã©ãŒã®å ¬åŒ : nâm+ f = 2ããé¢æ° f ãæ¶å»
ããã° (ãã®å ¬åŒãæžã㊠+1ç¹)
m = 3nâ 6 (14.467)
ãåŸããã.(2) (14.467)ã 2åãããã®ã«
n =âk=3
nk, 2m =âk=3
knk (14.468)
ãä»£å ¥ããã° (ããã 2ã€ã®é¢ä¿ã®ãã¡, 1ã€ã«ã€ããŠæ°ãã€ã㊠+1ç¹. 2ã€ãšãæ°ã¥ããŠ+3ç¹)âk=3
knk = 6âk=3
nk â 12 (14.469)
ãåŸãããã, åã®äžã®ã¯ããã®æ°é ãæžãåºããŠã¿ããš
3n3 + 4n4 + 5n5 + 6n6 + 7n7 + 8n8 + · · · = 6(n3 + n4 + n5 + n6 + n7 + n8 + · · ·)â 12(14.470)
ããªãã¡
3n3 + 2n4 + n5 â n7 â 2n8 â · · · = 12 (14.471)
ãæãç«ã€.
ãã㯠244ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
(3) (2)ã§åŸãããé¢ä¿åŒãã
3n3 + 2n4 + n5 â n7 â 2n8 â · · · â 12 = 0 †3n3 + 2n4 + n5 â 12 (14.472)
ã§ãããã
3n3 + 2n4 + n5 ⥠12 (14.473)
ã§ãã. ãŸã, æããã« (3n3 + 3n4 + 3n5) ⥠3n3 + 2n4 + n5 ã§ãããã, ãããã®äžçåŒããçŽã¡ã«
n3 + n4 + n5 ⥠13
(3n3 + 2n4 + n5) ⥠13à 12 = 4 (14.474)
åŸã£ãŠ, ã°ã©ã Gã«ã¯æ¬¡æ°ã 5以äžã®ç¹ã 4ã€ä»¥äžå«ãŸããããšã瀺ãã.
åé¡ 4 (é ç¹ 15ç¹)
(1)(2)ããŒã¿ãŒã¹ã³ã»ã°ã©ãã¯å³ 14.250ã§äžããããé£çµã°ã©ãã§ãã, å³ã«ç€ºããããã«èŸºåœ©è²ã§ããã®ã§, ãã®åœ©è²ææ°ã¯ 4ã§ãã (ããŒã¿ãŒã¹ã³ã»ã°ã©ããæã㊠+2ç¹).
1
2
1
2
3
1
3 3
32
2
2
14 1
å³ 14.250: ããŒã¿ãŒã¹ã³ã»ã°ã©ãã®åœ©è². 蟺ã«ä»ãããæ°åãåè²ãè¡šã.
(3)ãŸã, G ã 3次ã®ããã«ãã³ã»ã°ã©ããªã®ã§ãããã, åç¹ã§ããã«ãã³éè·¯ã«å±ãã 2蟺ãããã«ãã³éè·¯ã«æ²¿ã£ãŠäºãéãã« 2è² (è² 1ãš 2ãšããã)㧠1â 2â · · · ã®ããã«èŸºåœ©è²ãã. åç¹ã§æ®ãã® 1蟺ã 1,2 ãšç°ãªãè² 3ã§åœ©è²ããã°, Gã® 3圩è²ãå®æãã. ãã£ãŠ Gã®åœ©è²ææ°ã¯ 3ã§ãã.
(4) (2)ãã, 3次ã®ã°ã©ãã§ããããŒã¿ãŒã¹ã³ã»ã°ã©ãã®åœ©è²ææ°ã¯ 4ã§ãã, ãã㯠(3)ã§ç€ºãã 3次ã®ã°ã©ããããã«ãã³ã»ã°ã©ãã§ããããã®å¿ èŠæ¡ä»¶ã§ããã圩è²ææ°ã 3ããæºãããªã. åŸã£ãŠ,ããŒã¿ãŒã¹ã³ã»ã°ã©ãã¯ããã«ãã³ã»ã°ã©ãã§ã¯ãªã.
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2005幎床 ææ«è©Šéšç·è© (æ å ±å·¥åŠç§ 3幎ç/é»åå·¥åŠç§ 4幎ç)
å¹³æ17幎床 ã°ã©ãçè« ææ«è©Šéš ç·è© (9/16 å®æœ)
ã°ã©ãçè«ã®ææ«è©Šéšã®æ¡ç¹ãããŠã¿ãŸãã. åéšè æ° 92人, æ¬ åžæ° 8人, æé«ç¹ 50ç¹ (50ç¹æºç¹), æäœç¹ 17ç¹, å¹³åç¹ 35.47ç¹ã§ãã, åŸç¹ååžã¯äžèšã®ããã«ãªããŸãã.
15-19 ***
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45-49 *********
50 ******
åé¡ 1 ãš åé¡ 2 ã¯ãšãŠãç°¡åãªåé¡ã§ãã, çããã®åºæ¥ãè¯ãã£ãã§ã. ãã ã, åé¡ 2 ã®çæ¯çŽæ°
åã®èšç®ã§ãã¹ãç¯ããããã«æžç¹ãããçæ¡ãå€æ°èŠåããããŸãã. ãã®å€§å 2é¡ãã§ããªãã£ãå Žå, ä»åã®ãã¹ãã§ç¹æ°ãåãã®ã¯é£ããã£ãããã§ã.
åé¡ 3 ã®å°å (1)ã¯è©Šéšäžã«ãèšããŸããã, åé¡æã«äžããããã°ã©ãGã®å®çŸ©ã«åŸããš, æç«ãã¹ããªã®ã¯çåŒã§ã¯ãªã, m †3nâ6ãšããäžçåŒã«ãªããŸã. ããã瀺ããŠããããã°æ£è§£ãšããŸãã. ãªã,ãã®æ¡ä»¶ãåé¡æã«äžããçåŒ : m = 3nâ6ã«ããã«ã¯, ã°ã©ã Gã«å¯ŸããŠããã«ã(*) ã©ã®é£æ¥ããªã 2ç¹ãçµãã§ãå¹³é¢ã°ã©ããšãªããªãããšããæ¡ä»¶ã課ãå¿ èŠããããŸã. ãã®æ¡ä»¶ãèæ ®ããã°, m = 3nâ 6ãæºãããªãå³ 15.251ã®ãããªã°ã©ã㯠Gããé€å€ãããããšã«ãªããŸã. ãã®æ¡ä»¶æ (*)ã®æ¬ èœã¯ãã¡
å³ 15.251: ãã®é»ç·ã§çµã°ããå¹³é¢ã°ã©ãã¯åé¡æã®æ¡ä»¶ã¯æºããã, èµ€ç·ã 1 æ¬å ããŠãäŸç¶ãšããŠå¹³é¢ã°ã©ãã§ãã, ããã«æããæ¡ä»¶ (*) ã¯æºãããªãã®ã§, é»ç·ã®å¹³é¢ã°ã©ãã«å¯Ÿã, çåŒ m = 3n â 6 ãæãç«ãã (m = 8, 3n â 6 = 9), 極倧平é¢ã°ã©ãã§ã¯ãªã. (m †3n â 6 ã¯æºãã).
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
ãã®ãã¹ã§ãã, å°å (2)(3)以é㯠(ãããè©Šéšäžã«èšããŸããã), å°å (1)ã®çåŒ : m = 3nâ 6ã®æç«ãä»®å®ããã°ç¬ç«ã«ç€ºãããšãã§ããã®ã§, ç¹ã«çãã«ç¹æ°ãã€ãããšããããšã¯ããŸããã§ãã. ãªã,æ¡ä»¶ (*)ãæºãããããªå¹³é¢ã°ã©ãã極倧平é¢ã°ã©ããšåŒãã§ããŸã (ã€ãŸã, éé£æ¥ç¹éã« 1æ¬ã§ã蟺ãè¿œå ãããšå¹³é¢ã°ã©ããšãªããªããªã£ãŠããŸããšããæå³ã§ã極倧ãã§ãããšããããã§ãã).
åé¡ 4 ã«é¢ããŠã¯, ããŒã¿ãŒã¹ã³ã»ã°ã©ããæããªãã£ãè ãæ°åããŸãã. ãã®ã°ã©ãã¯è¬çŸ©ã§ã, ã¬ããŒãåé¡ã§ãäœåºŠãåºãŠããã°ã©ããªã®ã§, æããªããã°ãããŸãã. ãã®ã°ã©ããæããªãæç¹ã§ãã®åé¡ã®ã»ãšãã©ãäžæ£è§£ãšãªããŸãã, å¯äžå°å (3)ã ããç¬ç«ããŠããã®ã§, ãã®åé¡ã ãæ£è§£ã®è ãè€æ°åããŸãã.ãªã, 解çã®äœãæ¹ã«ãã£ãŠã¯, å°å (2)(3)ãã§ããªããŠãå°å (4)ã¯ç€ºããŠããŸãããã§ãã, ãã®å°å
(4)ã®å€å®çç±ãæ£åœæ§ããã€ããã«ã¯ (2)(3)ã®æ£è§£ãäžå¯æ¬ ãªã®ã§, å³ããããã§ãã, ãã®å°å (2)(3)ã®æ£è§£ãåæãšããŠå°å (4)ãæ¡ç¹ããŠãããŸãïŒã€ãŸã, å°å (2)(3)ãééã£ãŠããå Žåã«ã¯å°å (4)ã¯ç¡æ¡ä»¶ã«äžæ£è§£).
ã¬ããŒã課é¡ããã³åºåžç¹ãèæ ®ããç·åæ瞟ã¯ä»é±äžã«åºã, äžåæ Œè ã®ã¿ãåŠç±çªå·ã«ãŠæ²ç€ºããŸã.ãŸã, ã¬ããŒãããããªãã«åºããŠããã, ãã¹ããæ¬ åžããè ãæ°åããŸã. ãã®è ãåæã«æ²ç€ºããŸãã®ã§, ç æ°ç, ãã¹ããåããããªãã£ãæ£åœãªçç±ãããå Žåã®ã¿è¿œå 課é¡ãèããããšæããŸã.
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å¹³æ18幎床 ã°ã©ãçè« ææ«è©Šéšåé¡ (9/20 å®æœ ãåºé¡è : äºäž çŽäž)
⻠泚æäºé : åé¡çšçŽã¯ãã®è¡šçŽãå ¥ã㊠2ããŒãžãã, åé¡ 1 ïœ åé¡ 4 ã®å€§åèš 4é¡ã§ãã (50ç¹æºç¹). 解ççšçŽ, èšç® (äžæžã)çšçŽã¯å 1æé åžãã. 解ççšçŽã«ã¯æ°å, åŠç§åŠççªå·ãèšå ¥ã, è£é¢ã
䜿ãéã«ã¯ãè£ã«ç¶ãããšèšå ¥ããããš. è©Šéšéå§åŸ 30åéã¯é宀ã§ããªã. ãŸã, äžåºŠé宀ããå Žåã«ã¯åå ¥å®€ã§ããªãã®ã§æ³šæããããã«. ã©ã®åé¡ãã解ããŠãããã, å¿ ã該åœããåé¡çªå·ãæèšããŠããçæ¡ãäœæããããš. å¶éæé 90å.
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⻠解çãçµã, é宀ããéã«ã¯å¿ ã解ççšçŽãæåºã, 解çäŸã 1éšæã¡åž°ãããš.â» æ瞟ååžã»æ¡ç¹åºæºãªã©ã¯ææ¥ä»¥é, ã§ããã ãæ©ãææã«è¬çŸ©HPäžã«ãŠå ¬éãã. èªåèªèº«ã®æ瞟
ã®ç¥ãããè 㯠10/2以éã«æ å ±ç§åŠç 究ç§æ£ 8-13ãŸã§æ¥ãããã«.
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
åé¡ 1 (é ç¹ 10ç¹) (ããŒã¯ãŒã : å®å šã°ã©ã, å®å šäºéšã°ã©ã, è»èŒª, ãªã€ã©ãŒã»ã°ã©ãã®å€å¥)
ãªã€ã©ãŒã»ã°ã©ãã«é¢ããŠä»¥äžã®åãã«çãã. åã (1)ïœ(3)ã«çãã.
(1)å®å šã°ã©ã Kn ããªã€ã©ãŒã»ã°ã©ããšãªãããã«ç¹æ° nãæºããã¹ãæ¡ä»¶ãæ±ãã.(2)å®å šäºéšã°ã©ã Ks,t ããªã€ã©ãŒã»ã°ã©ããšãªãããã«, s, tãæºããã¹ãæ¡ä»¶ãæ±ãã.(3)ã©ã®ãã㪠nã«å¯ŸããŠè»èŒªWn ã¯ãªã€ã©ãŒã»ã°ã©ããšãªãã ? çç±ãšäœµããŠçãã.
åé¡ 2 (é ç¹ 10ç¹) (ããŒã¯ãŒã : k-æåãããªãåçŽã°ã©ãã®èŸºæ°ã®äžé, æ°åŠçåž°çŽæ³)
ã°ã©ãG㯠nåã®ç¹ãããªãã°ã©ãã§ãããšãã. Gã«ã¯æåã kåãããšãããš, Gã®èŸºæ°mã®äžéã¯
nâ kã§ããããš, ããªãã¡, 次ã®äžçåŒ :m ⥠nâ k
ãæãç«ã€ããšã蟺æ°mã«é¢ããæ°åŠçåž°çŽæ³ã«ãã瀺ã.
åé¡ 3 (é ç¹ 10ç¹) (ããŒã¯ãŒã : é£æ¥è¡å, å šåæšãšãã®ç·æ°, è¡åæšå®ç)
(1)é£æ¥è¡åAã
A =
âââ
0 1 11 0 11 1 0
âââ
ã§äžããããã°ã©ã Gãå³ç€ºã, ãã®ã°ã©ã Gã®å šåæšãå šãŠæã (3ç¹).(2)å®å šã°ã©ã K4ã®ç¹è¡åãæžã. ãŸã, è¡åæšå®çããå®å šã°ã©ãK4ã®å šåæšã®ç·æ°ãæ±ãã (7ç¹).
åé¡ 4 (é ç¹ 20ç¹) (ããŒã¯ãŒã : ç¹åœ©è², 圩è²å€é åŒ, 蟺ã®é€å»ãšçž®çŽ)
GãåçŽã°ã©ããšã, Gããä»»æã® 1蟺 eãé€å»ããŠåŸãããã°ã©ãã G-e, çž®çŽããŠåŸãããã°ã©ããG\e ãšãããš, Gã®åœ©è²å€é åŒ PG(k)ã¯
PG(k) = PGâe(k)â PG\e(k)
ã®ããã«å解ããããšãã§ãã.
(1) 4è§åœ¢ Gã«å¯ŸããŠ, G-e, G\e ãããããå³ç€ºãã (5ç¹).(2) 4è§åœ¢ Gã®åœ©è²å€é åŒã kã®é¢æ°ãšããŠæ±ãã (5ç¹).(3)ç¹æ° 4ã®äžè¬é£çµã°ã©ã G, æš T4, å®å šã°ã©ã K4 ã®åœ©è²å€é åŒã®éã«ã¯æ¬¡ã®äžçåŒãæãç«ã€ããš
ã瀺ã (10ç¹).PK4(k) †PG(k) †PT4(k)
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â» ååé¡/å°åã®é ç¹ã¯åé¡çšçŽã«èšããéã. ãã以å€ã«ãéšåç¹ãäžããå Žåããã.
åé¡ 1 (é ç¹ 10ç¹)
(1)å®å šã°ã©ã Kn ã®ä»»æã® 1ç¹ã®æ¬¡æ°ã¯ nâ 1ã§ãããã, ãªã€ã©ãŒã®å®çãã nâ 1 = å¶æ°ã®å Žåã«éã, Kn ã¯ãªã€ã©ãŒã»ã°ã©ããšãªã. ãã£ãŠ, n = 2m+ 1 (m = 1, 2, · · ·) ãçã.
(2)ç¹æ° t, sãå¶æ°ã§ããã°, é»,çœã§è²åãããã 2ã°ã«ãŒãã®ç¹ããããã亀äºã«çµç±ããŠããšã«æ»ããªã€ã©ãŒå°éãäœãããšã¯åžžã«å¯èœã§ãã. ãã£ãŠ, t, sãšãã«ãå¶æ°ãçã.
(3)è»èŒªã¯å šãŠã® nã«å¯ŸããŠ, ãµã€ã¯ã« Cnâ1ãš 1ç¹ãšã®çµåéšã®æ¬¡æ°ã¯ 3 (å¥æ°)ã§ãããã, ãªã€ã©ãŒã®å®çãããªã€ã©ãŒã»ã°ã©ããšã¯ãªããªã.
åé¡ 2 (é ç¹ 10ç¹) ã
空ã°ã©ãm = 0ã®ãšãã¯èªæã§ãã, n = kãã, 0 †0â 0 = 0ã§æç«ãã. 蟺æ°ãm0 â 1ã®ãšãã«äžçåŒã®æç«ãä»®å®ãã. ãã®ãšã, åçŽã°ã©ã Gããä»»æã®èŸºã 1æ¬åé€ããå Žå, æåæ°, ç¹æ°, 蟺æ°ã¯ã©ã®ããã«å€åããã®ããèå¯ãããš
æåæ° : k â k + 1
ç¹æ° : n â n
èŸºæ° : m0 â m0 â 1
ãšãªããã, äžã®ç¢å°ã®å³åŽã®ããããã®é (k + 1, n,m0 â 1)ã«é¢ããŠäžçåŒãäœããš
m0 â 1 ⥠nâ (k â 1)
ãæç«ãã. åŸã£ãŠ, ãã®èŸºæ°m0 â 1ã«é¢ããäžçåŒã®æç«ãä»®å®ã, ãããã蟺æ°m0 ã«ã€ããŠã®äžç
åŒã®æç«ãå°ãã°ãã. ããã¯äžäžçåŒãæžãçŽãã°çŽã¡ã«
m0 ⥠nâ kãåŸãã, m0ã«é¢ããŠæç«. 以äžãã, å šãŠã®mã«å¯ŸããŠm ⥠nâ kã®æç«ãã. (蚌æçµãã)
åé¡ 3 (é ç¹ 10ç¹)
(1)é£æ¥è¡åAãæã€ã°ã©ã G : å³ 17.252 (å·Š)ãšãã®å šåæš (å³)ãšãªã.(2)å®å šã°ã©ã K4ã®ç¹è¡åDã¯, ãã®å®çŸ©ãã
D =
ââââââ
3 â1 â1 â1â1 3 â1 â1â1 â1 3 â1â1 â1 â1 3
ââââââ
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1 2
3
1 2
3
1 2
3
1 2
3
å³ 17.252: é£æ¥è¡å ã§äžããããã°ã©ã G (å·Š) ãšãã® 3 ã€ã®å šåæš (å³).
ã§ãã, ãã® i = j = 4ã§ã®äœå åã, å®å šã°ã©ãK4ã®å šåæšã®ç·æ° Ï(K4)ãäžããã®ã§, èšç®ãããš
Ï(K4) =
â£â£â£â£â£â£â£3 â1 â1â1 3 â1â1 â1 3
â£â£â£â£â£â£â£ = 3â£â£â£â£ 3 â1â1 3
â£â£â£â£â (â1)â£â£â£â£ â1 â1â1 3
â£â£â£â£ââ£â£â£â£ â1 â1
3 â1
â£â£â£â£ = 24â 4â 4 = 16 (å)
åé¡ 4 (é ç¹ 20ç¹)
(1) 4è§åœ¢ã«é¢ã㊠G-e , G\e ãæããš, ããããå³ 17.253ã®ããã«ãªã.
G - e G \ e
å³ 17.253: 4 è§åœ¢ G ã«é¢ãã G-e ãš G\e.
(2)åé¡æã«äžããããé¢ä¿åŒ, åã³, (1)ã®çµæãçšãããš, 次ã®åœ©è²å€é åŒãåŸããã.
PG(k) = PGâe(k)â PG\e(k) = k(k â 1)3 â k(k â 1)(k â 2) = k4 â 4k3 + 6k3 â 3k
(3)ç¹æ°ã 4ã®å®å šã°ã©ãK4ãã蟺ã 1æ¬ãã€åæžããŠãã£ãå Žå, 圩è²å€é åŒã¯ã©ã®ããã«æ¯èãã®ãã å³ 17.254ã«èŒãã. 蟺ã 1æ¬ãã€åé€ããŠããããšã«ãã, 圩è²å€é åŒã¯ k(kâ 1)(kâ 2)(kâ 3)â
k k-1
k-3 k-2
k
k-1 k-2
k-2
k
k-1 k-1
k-2kk-1
k-1 k-1
å³ 17.254: å®å šã°ã©ããã蟺ã 1 æ¬ãã€åé€ããŠãããšæåŸã«ã¯æšãåŸããã.
k(k â 1)(k â 2)2 â k(k â 1)2(k â 2)â k(k â 3)3 ã®ããã«å調ã«å¢å ã, æçµçã«åŸãããã°ã©ãã¯ç¹æ° 4ãããªãæš T4 ã§ãã. ãŸã, å®å šã°ã©ãã¯å šãŠã®ç¹ãäºãã«ã€ãªãã£ãŠããã®ã§, ç¹åœ©è²ã«ãããŠã¯å šãŠã®ç¹ã®è²ãä»ã®ã©ã®å šãŠã®ç¹ã®è²ãšãç°ãªãè²ã§åœ©è²ããªããã°ãªãã, åŸã£ãŠ, æããã«äžããããè²ã®æ° kã«å¯Ÿã, å®å šã°ã©ãã®ç¹åœ©è²ã®ä»æ¹ã®æ°ã¯é£çµã°ã©ãäžã§æãå°ãªã. ç¹æ°ã 4ã®äžè¬ã®é£çµã°ã©ãã¯ãã®å®å šã°ã©ããšæšã®éã«å ¥ã£ãŠããã®ã§, ãããã®åœ©è²å€é åŒã®éã«ã¯
PK4(k) †PG(k) †PT4(k)
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20-24 *******
25-29 *********
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åé¡ 2 ã¯è§£çäŸã®ä»ã«æ§ã ãªç€ºãæ¹ããããšã¯æããŸãã, 蟺ã®æ¬æ°ã®äžéã§ããã, åæåãæšã§ãã
ãšããåæã®äžã§è°è«ããŠãè¯ãã§ã. åé¡ 3 ã® (2) ã¯ãã¡ãã®æãã»ã©ã§ããªãã£ãã®ã§, é ç¹ãåœåã® 7ç¹ãã 5ç¹ã«äžããŸãã. è¡ååŒã®åçŽãªèšç®ãã¹ã¯ãã€ãã¹ 2ç¹. å®å šã°ã©ã Kn ã®å šåæšã®åæ°
ã®å ¬åŒ nnâ2ãçšããŠèšç®ãã解çããããŸããã,ãç¹è¡åããè¡åæšå®çããšããåé¡ã®æå³ãããããšéäžçµéãé£ã°ããŠ, ãã®çµæã®éšå nnâ2 ã®ã¿ãçšããŠçã 16ãåºããå Žåã«ã¯å®å šãªæ£è§£ãšããããã«ã¯ããã, ãã€ãã¹ 3ç¹ãšããŠãããŸã. åé¡ 4 ã® (3)ã¯å ·äœçã«å šãŠã®ã°ã©ã Gãåèšã, ãã®åœ©è²å€é åŒãæ±ã, ãããæšãšå®å šã°ã©ãã®éã®å€ããšãããšãå ·äœçã«ç€ºããŠããã£ãŠãOK. ã°ã©ãGãš
ããŠäžè¬çãªã°ã©ãã§ã¯ãªã, ç¹å®ã®ã°ã©ã, ç¹ã« 4è§åœ¢ã«å¯ŸããŠã®ã¿ç€ºãã解çã«é¢ããŠã¯é ç¹ã®ååã®5ç¹ãäžããã«ãšã©ããŸãã (ããã§ãããªãçã).
ã¬ããŒã課é¡ã®æ瞟, åºåžç¹ãèæ ®ããæçµæ瞟㯠28æ¥ãŸã§ã«åºããŸãã®ã§, æ瞟ã®æ°ã«ãªãæ¹ã¯ 10æ 2æ¥ä»¥éã«æ å ±ç§åŠç 究ç§æ£ 8-13宀ãŸã§ãè¶ããã ãã.
ãŸã, åæ¥åäœã«é¢ããŠæ·±å»ãªåœ±é¿ããããšæãããé»åå·¥åŠç§ 4幎ã®åŠç 10å (åŠå æ²ç€ºæ¿ã«çºè¡šæžã¿)ã«å¯ŸããŠã¯è¿œå 課é¡ãåºããŸãã®ã§, è¬çŸ© HPã® [é£çµ¡ 5]ãåç §ããŠå¯Ÿå¿ããŠãã ãã.
å¹³æ 18幎 9æ 21æ¥ äºäžçŽäž
257
2007幎床 ææ«è©Šéš (é»åå·¥åŠç§ 4幎ç)
å¹³æ19幎床 ã°ã©ãçè« ææ«è©Šéšåé¡ (9/3 å®æœ ãåºé¡è : äºäž çŽäž)
⻠泚æäºé : åé¡çšçŽã¯ãã®è¡šçŽãå ¥ã㊠2ããŒãžãã, åé¡ 1 ïœ åé¡ 4 ã®å€§åèš 4é¡ã§ãã (50ç¹æºç¹). 解ççšçŽ, èšç® (äžæžã)çšçŽã¯å 1æé åžãã. 解ççšçŽã«ã¯æ°å, åŠç§åŠççªå·ãèšå ¥ã, è£é¢ã
䜿ãéã«ã¯ãè£ã«ç¶ãããšèšå ¥ããããš. è©Šéšéå§åŸ 30åéã¯é宀ã§ããªã. ãŸã, äžåºŠé宀ããå Žåã«ã¯åå ¥å®€ã§ããªãã®ã§æ³šæããããã«. ã©ã®åé¡ãã解ããŠãããã, å¿ ã該åœããåé¡çªå·ãæèšããŠããçæ¡ãäœæããããš. å¶éæé 90å.
ã解çå§ããã®åå³ããããŸã§åé¡ååãéããªãããš
⻠解çãçµã, é宀ããéã«ã¯å¿ ã解ççšçŽãæåºã, 解çäŸã 1éšæã¡åž°ãããš.â» æ瞟ååžã»æ¡ç¹åºæºãªã©ã¯ææ¥ä»¥é, ã§ããã ãæ©ãææã«è¬çŸ©HPäžã«ãŠå ¬éãã. èªåèªèº«ã®æ瞟
ã®ç¥ãããè 㯠9/10以éã«æ å ±ç§åŠç 究ç§æ£ 8-13ãŸã§æ¥ãããã«.
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
åé¡ 1 (é ç¹ 10ç¹) (ããŒã¯ãŒã : å®å šäžéšã°ã©ã, 蟺æ°, é£æ¥è¡å)
ãªã€ã©ãŒã»ã°ã©ãã«é¢ããŠä»¥äžã®åã (1)ïœ(3)ã«çãã.
(1)å®å šäžéšã°ã©ãK2,2,2ãæã (5ç¹).(2)å®å šäžéšã°ã©ãKr,s,tã®èŸºæ°ã r, s, tã®ãã¡ããå¿ èŠãªãã®ãçšããŠè¡šã (3ç¹).(3) (1)ã§æããå®å šäžéšã°ã©ãK2,2,2ã®é£æ¥è¡åãæ±ãã. ãã ã, åç¹ã®çªå·ãæèšããŠããçããããš (2ç¹).
åé¡ 2 (é ç¹ 10ç¹) (ããŒã¯ãŒã : ãªã€ã©ãŒã»ã°ã©ã, ããã«ãã³ã»ã°ã©ã, å®å šã°ã©ã, å®å šäºéšã°ã©ã)
(1)ãªã€ã©ãŒã»ã°ã©ã, åãªã€ã©ãŒã»ã°ã©ããšã¯ã©ã®ãããªã°ã©ãã, ããããç°¡æœã«èª¬æãã. ãŸã, å®å šã°ã©ã K5ã¯ãªã€ã©ãŒã»ã°ã©ã, åãªã€ã©ãŒã»ã°ã©ã, ãã®ã©ã¡ãã§ããªãã°ã©ãã®ãã¡ã®ã©ãã§ããã, çç±ãšãšãã«çãã (5ç¹).
(2)ããã«ãã³ã»ã°ã©ã, åããã«ãã³ã»ã°ã©ããšã¯ã©ã®ãããªã°ã©ãã, ç°¡æœã«èª¬æãã. ãŸã, å®å šäºéšã°ã©ã K2,3ã¯ããã«ãã³ã»ã°ã©ã, åããã«ãã³ã»ã°ã©ã, ãã®ã©ã¡ãã§ããªãã°ã©ãã®ãã¡ã®ã©ãã§ããã, çç±ãšãšãã«çãã (5ç¹).
åé¡ 3 (é ç¹ 10ç¹)
1. (ããŒã¯ãŒã : å®å šã°ã©ã, é£çµã°ã©ã, ãããã¯ãŒã¯ã®ã€ãªããæ¹ãšä¿¡é ŒåºŠ)å®å šã°ã©ãK3 ã«é¢ã, ãã®åç¹ããµãŒãã«å¯Ÿå¿ã, K3 ã®ã€ãªããæ¹ãããããããã¯ãŒã¯ãããªã
ãŠãããã®ãšãã. ãã®ãããã¯ãŒã¯ã®å蟺ã確ç qã§æç·ããå Žå, ã©ãã«ä»ãã°ã©ããäŸç¶ãšããŠé£çµã°ã©ãã§ããå Žåã«éã, ãã®ãããã¯ãŒã¯ã¯æ£åžžã«æ©èœããããšãããã£ãŠãã. ãã®ãšã, ãã®ãããã¯ãŒã¯ãæ£åžžã§ãã確ç (ãããã¯ãŒã¯ã®ä¿¡é ŒåºŠ) Rã qã®é¢æ°ãšããŠæ±ã, å³ç€ºãã (3ç¹).
2. (ããŒã¯ãŒã : ç¹è¡å, è¡åæšå®ç, å šåæšãšãã®ç·æ°)é£æ¥è¡åAã
A =
ââââââ
0 1 1 01 0 0 11 0 0 20 1 2 0
ââââââ
ã§äžããããã°ã©ã Gã«é¢ããè¡åæšå®çã«ã€ããŠä»¥äžã®åãã«çãã.(1)ã°ã©ã Gã®ç¹è¡åDãæ±ãã (2ç¹).(2)è¡åæšå®çã«ãã, ã°ã©ã Gã®å šåæšã®ç·æ° Ï(G)ãæ±ãã (3ç¹).(3) (2)ã§åŸãããåæ°ã ãååšããå šåæšãå ·äœçã«å šãŠå³ç€ºãã (2ç¹).
ãã㯠258ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
åé¡ 4 (é ç¹ 20ç¹) (ããŒã¯ãŒã : ç¹åœ©è², 圩è²å€é åŒ, 蟺ã®é€å»ãšçž®çŽ)
1. å³ã®ãå倧ããè¡šãéé£çµã°ã©ããé£å士ã®ç¹ãåãè²ã«ãªããªãããã«ãèµ€ããéããé»ãã®äžè²ã§åœ©è²ããéã®å Žåã®æ°ãæ±ãã (7ç¹).
2. Gã¯ç¹æ° n, 蟺æ°mã®åçŽã°ã©ãã§ãããã®ãšãã. ãã®ãšã, 圩è²å€é åŒ: PG(k)ã®(i) äž»èŠé 㯠kn ã§ãã (3ç¹).(ii) knâ1 ã®ä¿æ°ã¯ âmã§ãã (5ç¹).(iii) åä¿æ°ã®ç¬Šå·ã¯æ£è² ã亀äºã«è¡šãã (5ç¹).ããããã蟺æ°mã«é¢ããæ°åŠçåž°çŽæ³ã«ãããããã蚌æãã.
ãã㯠259ããŒãžç®
261
2007幎床 ææ«è©Šéšè§£ç (é»åå·¥åŠç§ 4幎ç)
å¹³æ19幎床 ã°ã©ãçè« ææ«è©Šéšè§£ç (9/3 å®æœ ã解çäœæ : äºäž çŽäž)
â» ååé¡/å°åã®é ç¹ã¯åé¡çšçŽã«èšããéã. ãã以å€ã«ãéšåç¹ãäžããå Žåããã.
åé¡ 1 (é ç¹ 10ç¹)
(1)å®å šäžéšã°ã©ã K2,2,2ãæããšå³ 20.255ã®ããã«ãªã.
AB
C
K 2,2,2
å³ 20.255: å®å šäžéšã°ã©ã K2,2,2 ã®äœå³äŸ.
(2) Kr,s,tã®èŸºã®æ¬æ°ã¯ rs+ rt+ stæ¬ã§ãã.(3)å³ 3.49ã®ã°ã«ãŒãAã«å±ããå·ŠåŽã®ç¹ããæèšåšãã« 1, · · · , 6ãšåç¹ãžãšçªå·ãå²ãæ¯ããšé£æ¥è¡å
Aã¯ä»¥äžã®éã.
A =
âââââââââââ
0 0 1 1 1 10 0 1 1 1 11 1 0 0 1 11 1 0 0 1 11 1 1 1 0 01 1 1 1 0 0
âââââââââââ
(20.475)
åé¡ 2 (é ç¹ 10ç¹)
(1)ãªã€ã©ãŒã»ã°ã©ã : å蟺ãã¡ããã© 1åãã€éãéããå°éãããã°ã©ã.åãªã€ã©ãŒã»ã°ã©ã : å蟺ãã¡ããã© 1åãã€éãå°éãããã°ã©ã.ãŸã, å®å šã°ã©ã K5ã®å šãŠã®ç¹ã®æ¬¡æ°ã¯ 4ã§å¶æ°ã§ããã®ã§, ãªã€ã©ãŒã®å®çãã K5ã¯ãªã€ã©ãŒã»ã°
ã©ãã§ãããšçµè«ã¥ãããã. (⻠泚 : ãŸãã¯, å³ 20.256ã®ããã«å ·äœçã«éãããªã€ã©ãŒå°éã瀺ããŠãæ£è§£).
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
1
2
3
4
5
6
7
8
9
10
å³ 20.256: å®å šã°ã©ã K5. çªå·é ã«åãã°, éãããªã€ã©ãŒå°éãåŸããã.
(2)ããã«ãã³ã»ã°ã©ã : åç¹ãã¡ããã© 1åãã€éãéããå°éãããã°ã©ã.åããã«ãã³ã»ã°ã©ã : åç¹ãã¡ããã© 1åãã€éãå°éã®ããã°ã©ã.ãŸã, å®å š 2éšã°ã©ãK2,3ã¯äŸãã°, å³ 20.257ã®ãããªç¹ã®é ã§åãã°å šãŠã®ç¹ã 1åãã€éãã, å¿ ãåºçºç¹ä»¥å€ã®ç¹ã§çµããã®ã§åããã«ãã³ã»ã°ã©ãã§ãã.
1
2
3
4
5
å³ 20.257: å®å šäºéšã°ã©ã K2,3. çªå·é ã«åãã°, ããã«ãã³å°éãåŸãããã, ããã¯éããªã.
åé¡ 3 (é ç¹ 10ç¹)
1. å®å šã°ã©ãåã³, 蟺ã 1æ¬æç·ããã°ã©ã (3çš®é¡), 蟺ã 2æ¬æç·ããã°ã©ã (3çš®é¡), 蟺ãå šãŠæç·ããã°ã©ã (1çš®é¡) ã®ããããã®ã°ã©ããå³ 20.258ã«ç€ºã. ããã§æ³šæãã¹ããªã®ã¯, åç¹ããããã¯ãŒã¯ã®ãµãŒãã«å¯Ÿå¿ããã®ã§, ãå®å šã°ã©ãã®å Žåã, åã³, ã蟺ã 1æ¬ã ãæç·ããå Žåãã«éã,ãã®ãããã¯ãŒã¯ã¯æ£åžžã«æ©èœãã. ããããã®ç¢ºç㯠(1â q)3, 3q(1â q)2 ã§ãã. åŸã£ãŠ, ãããã¯ãŒã¯ã®ä¿¡é ŒåºŠ Rã¯ãããäž¡è ã®åã§äžããããã®ã§, qã®é¢æ°ãšããŠã® Rã¯
R(q) = (1â q)3 + 3q(1â q)2 (20.476)
ãšãªã. ãããå³ 20.259ã«æã.2.
(1)é£æ¥è¡åAã«ããäžããããã°ã©ã Gã¯å³ 20.260ã®ããã«ãªã. åŸã£ãŠ, æ±ããç¹è¡åDã¯
D =
ââââââ
2 â1 â1 0â1 2 0 â1â1 0 3 â20 â1 â2 3
ââââââ (20.477)
ãã㯠262ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
a
b c
a
cb
a
b c
a
b c
a
b c
a
b c
a
b c
a
b c
å³ 20.258: ããã§èãããããããã¯ãŒã¯ã®ç¶æ . äžãã, æç·ãŒã, 1æ¬æç·, 2 æ¬æç·, å šéšæç·ã®ã°ã©ã. ãããã¯ãŒã¯ãšããŠæ£åžžã§ããã®ã¯, æç·ãŒã, åã³, 1 æ¬æç·ã®å Žåã®ã¿.
0
0.2
0.4
0.6
0.8
1
0 0.2 0.4 0.6 0.8 1
R
q
å³ 20.259: ãããã¯ãŒã¯ã®ä¿¡é ŒåºŠ R ã®å蟺ã®æç·ç¢ºç q äŸåæ§.
ã§ãã.(2) i = j = 4ã§äœå åå±éããããšã«ãã, ã°ã©ã Gã®å šåæšã®åæ° Ï(G)ã¯
Ï(G) = (â1)4+4
â£â£â£â£â£â£â£2 â1 â1â1 2 0â1 0 3
â£â£â£â£â£â£â£ = (â1)
â£â£â£â£â£ â1 â12 0
â£â£â£â£â£ + 3â£â£â£â£ 2 â1â1 2
â£â£â£â£ = â2 + 3 · 3 = 7 (å)
(20.478)
ãšãªã.(3)ã°ã©ã Gã® 7éãã®å šåæšãå³ç€ºãããšå³ 20.261ã«ãªã.
åé¡ 4 (é ç¹ 20ç¹)
1. éé£çµã°ã©ããå倧ããæ§æããå šãŠã®æåã¯ç¹æ°ã 6ã®ãæšãã§ããããš, ç¹æ° nã®æšã®åœ©è²å€é
åŒã k(kâ 1)nâ1ã§äžããããããš, éé£çµã°ã©ãã®åã ã®æåã¯ä»ã®æåãšã¯ç¬ç«ã«åœ©è²ã§ããããš
ãã㯠263ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
1 3
24
G
å³ 20.260: é£æ¥è¡å A ã«ãã£ãŠå®çŸ©ãããã°ã©ã G.
1 3
2 4
1 3
2 4
1 3
2 4
1 3
2 4
å³ 20.261: é£æ¥è¡å A ã«ãã£ãŠå®çŸ©ãããã°ã©ã G ã®å šåæš. ãã ã, 蟺 3 â 4 ãåé€ããã, 蟺 4 â 3 ãåé€ãããã«ãã,ããã 4 ã€ã®ã°ã©ãã®äžã§èŸº 34 ãããã°ã©ãã«ã¯ãããã 1 ã€ãã€ç°ãªãã°ã©ããååšããã®ã§, èš 7 ã€ã®å šåæšãåŸããã.
ã«æ³šæãããš
På倧(k) = k(k â 1)nâ1 à k(k â 1)nâ1 à k(k â 1)nâ1 = k3(k â 1)3nâ3 (20.479)
åŸã£ãŠ, æ±ããå Žåã®æ°ã¯ n = 6, k = 3ã®å Žåã§ãããã
På倧(3) = 33 à 215 = 884736 (20.480)
ãšãªã.2. åè§£å ¬åŒ:
PG(k) = PGâe(k)â PG/e(k) (20.481)
ãçšããŠåäºå®ã蚌æãã. ãã ã, ããã§ã¯èŸºæ°mã«ã€ããŠã®åž°çŽæ³ãè¡ããã, 蟺æ°m, ç¹æ° nã®
ã°ã©ã Gã«å¯Ÿãã圩è²å€é åŒã P(m,n)G (k)ã®ããã«æžãããšã«ããã. ãã®ãšã, ã°ã©ã G â eã®èŸº
æ°ã¯mâ 1, ç¹æ°ã n, ã°ã©ãG/eã®èŸºæ°mâ 1, ç¹æ° nâ 1ã§ãããã, ãã®å®çŸ©ã®ããšã§åè§£å ¬åŒã¯
P(m,n)G (k) = P
(mâ1,n)Gâe (k)â P (mâ1,nâ1)
G/e (k) (20.482)
ãšãªã. 以äžã§ãã®å ¬åŒ (20.482)ãçšããŠèšŒæãè©Šã¿ã.(i) m = 1ã®ãšã, ã°ã©ã Gã¯ä»»æã® 2ç¹ã 1æ¬ã®èŸºã§çµã°ããŠãã, æ®ã nâ 2ç¹ã¯å€ç«ç¹ã§ããã¹ããªã®ã§, ãã®å Žåã®åœ©è²å€é åŒã¯ä¿æ°ãå«ããŠéœã«æ±ããããšãã§ããŠ
P(1,n)G (k) = k(k â 1)Ã knâ2 = kn â knâ1 (20.483)
ãšãªã. åŸã£ãŠ, æããã«é¡æãæºãããŠããããšãããã. 次ã«èŸºæ°mâ 1ã®å Žåã«é¡æã®æç«ãä»®å®ããã. ã€ãŸã, 圩è²å€é åŒã§æžãã°
P(mâ1,n)
Gâ² (k) = kn +nâ
i=1
αiknâi (20.484)
ã蟺æ°m, ç¹æ° nã®ä»»æã®ã°ã©ãGâ²ã«å¯ŸããŠä»®å®ãã. ãã®ãšã, ã°ã©ãGããä»»æã®èŸº eãåé€
ããã°ã©ã Gâ eã®åœ©è²å€é åŒã¯, ã°ã©ãGâ eã蟺æ°mâ 1,ç¹æ° nã§ããããšãã, äžã®ã°ã©ã
ãã㯠264ããŒãžç®
ã°ã©ãçè« 2003 ïœ 2007 åæµ·éå€§åŠ å€§åŠé¢æ å ±ç§åŠç ç©¶ç§ äºäžçŽäž
Gâ²ã®ã«ããŽãªãŒã«å ¥ãããšãèããŠ
P(mâ1,n)Gâe (k) = kn +
nâi=1
αiknâi (20.485)
ãšãªã. äžæ¹, Gã®èŸº eãçž®çŽããããšã«ããåºæ¥äžããã°ã©ãG/eã«é¢ãã圩è²å€é åŒã¯, çž®çŽæäœã«ãã£ãŠç¹æ°ã nâ 1ã«ãªã£ãŠããããšã«æ³šæããŠ
P(mâ1,nâ1)G/e (k) = knâ1 +
nâi=2
βiknâi (20.486)
ã§ãã. åŸã£ãŠ, åè§£å ¬åŒ (20.482)ãã, 蟺æ°m, ç¹æ° n ã®ã°ã©ã Gã®åœ©è²å€é åŒã¯
P(m,n)G (k) = kn â (1â α1)knâ1 + (knâ2 以äžã®é ) (20.487)
ãšãªã. åŸã£ãŠ, 蟺æ°mã®å Žåã«ãé¡æãæç«ãã. åŸã£ãŠ, ä»»æã®èªç¶æ°mã«å¯ŸããŠé¡æãæç«
ãã.(ii) m = 1ã®ãšã, æ¢ã«æ±ããŠããããã«
P(1,n)G (k) = kn â knâ1 (20.488)
ã§ããããé¡æã®æç«ã¯æããã§ãã. ããã§èŸºæ°mâ 1ã®ãšãã«é¡æã®æç«ãä»®å®ãã. ã€ãŸã,蟺æ°mâ 1, ç¹æ° nã®ã°ã©ã G
â²ã«å¯ŸããŠ
P(mâ1,n)G (k) = kn â (mâ 1)knâ1 +
nâi=1
αiknâi (20.489)
ãšããã. ãã®ãšã (i)ãšåæ§ã®èå¯ã«ãã
P(mâ1,n)Gâe (k) = kn â (mâ 1)knâ1 +
nâi=1
αiknâi (20.490)
P(mâ1,nâ1)G/e (k) = knâ1 +
nâi=2
βiknâi (20.491)
ãåŸããã. åŸã£ãŠ, åè§£å ¬åŒ (20.482)ãçšãããšèŸºæ°m, ç¹æ° n ã®ã°ã©ã Gã®åœ©è²å€é åŒã¯
P(m,n)G (k) = kn â (mâ 1)knâ1 â knâ1 + (knâ2 以äžã®é )
= kn âmknâ1 + (knâ2 以äžã®é ) (20.492)
ãšãªã, 蟺æ°mã®å Žåã«ãé¡æãæç«ãã. åŸã£ãŠ, ä»»æã®èªç¶æ°mã«å¯ŸããŠé¡æãæç«ãã.(iii) m = 1ã®å Žåã«ã¯
P(1,n)G (k) = kn â knâ1 (20.493)
ããé¡æã¯æç«ãã. (ãã®å Žåã«ã¯ 2ã€ã®é ã®ã¿ã§ããããšã«æ³šæ.) ããã§, 蟺æ°mâ 1ã®å Žåã«é¡æã®æç«ãä»®å®ãã. ã€ãŸã, 圩è²å€é åŒã§æžãã°
P(mâ1,n)
Gâ² (k) = kn +nâ
i=1
(â1)iαiknâi (20.494)
ã蟺æ°m, ç¹æ° nã®ä»»æã®ã°ã©ãGâ²ã«å¯ŸããŠä»®å®ãã. ãã ã, é ããšã®ç¬Šå·ããã¡ã¯ã¿: (â1)iã§
å°å ¥ããé¢ä¿ã§, å šãŠã®ã€ã³ããã¯ã¹ iã«å¯Ÿã㊠αi > 0ã§ãããšããŠä»¥äžã®è°è«ãé²ããªããŠã¯ãª
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ããªãããšã«æ³šæããã. ãããš, (i)(ii)ãšåæ§ã®èå¯ã«ãã
P(mâ1,n)Gâe (k) = kn +
nâi=1
(â1)iαiknâi (20.495)
P(mâ1,nâ1)G/e (k) = knâ1 â
nâi=2
(â1)iβiknâi (20.496)
ãåŸããã. αi ãšåæ§ã®çç±ã§, å šãŠã® iã«å¯Ÿã㊠βi > 0ã§ãã. åŸã£ãŠ, åè§£å ¬åŒ (20.482)ãçšãããšèŸºæ°m, ç¹æ° n ã®ã°ã©ãGã®åœ©è²å€é åŒã¯
P(m,n)G (k) = kn â knâ1 + (â1)α1k
nâ1 +nâ
i=2
(â1)i(αi + βi)knâi
= kn âmknâ1 +nâ
i=2
(â1)i(αi + βi)knâi (20.497)
ãšãªã. ãã㧠(ii)ã§ç€ºãããäºå®: α1 = mâ 1ãçšãã. αi + βi > 0ãã, mã®ãšãã®é¡æã®æç«ã瀺ããã®ã§, ä»»æã®èªç¶æ°mã«å¯ŸããŠé¡æãæç«ãã.
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