Build and Design 4 Stroke Engine EnglishPapers

5/29/2018 Build and Design 4 Stroke Engine EnglishPapers

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International Conference on e-LearningBandung, November 23-24, 2011

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BUILD AND DESIGN FOUR STROKE ENGINE SIMULATOR:

VISUALIZATION OF OTTO CYCLE

Dani Hidayatuloh1and Aciek Ida Wuryandari

2

1Public Vocational High School of 8 Bandung

Kliningan Street 31, Bandung 40264

2School of Electrical Engineering and Informatics

Bandung Institute of Technology, Ganesha Street 10, Bandung 40132, Indonesia

[email protected], +62 856 [email protected], +62 811 220329

ABSTRACT

Visualization Otto cycle is the visualization in the form of three-dimensional (3D) of the crank shaftmechanism which cooperate with the piston mechanism, the valve mechanism and several other

systems to meet the working principle of 4 stroke motor fuel in Otto cycle. Otto cycle is a motor fuel

cycle that applies in this type of motor gasoline 4 steps, namely to generate one-time effort (force /power) then requires 4 (four) steps translasli / alternating piston and 2 (two) rotation / rounds (7200 )

crankshaft. Four piston step is composed of successive steps of suction, compression stroke, work

steps and exhaust step. Every single step piston will rotate the crankshaft of 1800 in other words 1(one) step piston equal to 1 / 2 rotation of the crankshaft. Then the sequence of steps piston and

crankshaft rotation and processing the mixture of fuel gas that is chemically into gases force the gas-

producing mechanical torque is called the Otto cycle.

The process of chemical processing of fuel and air mixture is analyzed further with the calculation ofthermodynamic calculations that analyze the Otto cycle combustion pressure (P3) which is then termed

the gas force (Fg). While the mechanical process using a mathematical model of the crankshaft torqueformulation mechanical calculations to obtain the torque value due to a gas called gas crankshaft

torque (Tg). Tg influenced by variables such as style gas (Fg), crank angle () and the ratio of shaft

engkolnya itself in a variety of crank rotation. Implementation is then tested the function testing anduser trials. Function testing was found that all the functions of the crankshaft torque modeling

appropriate design concept. User test results indicate the respondents strongly agreed, modeling can

inform the shape and workings of the crankshaft torque embracing systems like the real Otto cycle.

Keywords: modeling, Otto cycle, torque, crank shaft, gas, motor fuel.

1. PRELIMINARY

Visualization Otto cycle is a visual translation of the working principle of 4 stroke motor fuels which are abstract.

Said to be abstract because the motor fuels 4 steps to work in a confined space and is not allowed to be seen bynaked eye directly.

Among researchers or designers of automotive engines, the abstract about the working principle of 4 strokes motor

fuel has always been thoroughly studied in order to obtain the perfection of the design approach to perfectionproduced the original object (motor gasoline 4 stroke - 4-cylinder). Among practitioners as well as mechanics,

studying the working principle of 4 stroke motor fuel is a form of awareness of how to provide service / maintenanceof the machine are correct or appropriate standard operating procedure (SOP). In the realm of education either

college or secondary school level, the working principle of 4 stroke motor fuel is a scientific process that led

debriefing before becoming a researcher engine / or before becoming a mechanical designer.

978-602-19271-0-6 ICEL 2011


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Simulation of combustion 4 stroke motor that simulates the working principle of the talent the 4 steps according to

the principle of Otto cycle is a simulation made in the form of software through a computer media that provides an

understanding of how combustion 4 stroke Otto cycle of work followed by manipulating some input parameters are

adjusted to actual conditions . User object simulation is concerned with the practitioner / vocational high schoolstudents as prospective mechanics, then by acquiring comprehension about the working principle of the user is

expected to handle the servicing / maintenance of the machine according to SOP.

Some simulators motor fuels 4 steps in accordance with the principle of Otto cycle has been made and most of themin the form of two-dimensional (2D). In addition to still 2D, weakness is not to include input parameters that can be

manipulated to better represent the actual motor fuel. In short, the advantages of this simulation is able to visualize

the working principle of 4 stroke motor fuel according to the principle of Otto cycle in 3D with the addition of the

input parameters in terms of manipulation of the influence of fuel gas and air mixture and the influence of the degree

of ignition of the engine performance in this regard is limited to obtain the output parameters of the form gas torqueat the crankshaft due to a force on the gas piston.

2. RESEARCH OBJECTIVES

The purpose of this thesis research is to make visualization Otto cycle by calculating the theoretical thermodynamic

processes that occur in motor fuels (in cylinders) to get the value of the combustion pressure (P3) as the gas force(Fg), which is a variable gas torque of the crankshaft through the calculation of the efficiency of the cycle ( ) Otto

and modeling the gas torque on the crankshaft 3D simulator motor fuels 4 steps.

3. Otto Cycle Efficiency Calculations

Figure 1.1 Otto Cycle

Volume of Gas

The volume of gas is a first condition in the calculation of Otto cycle that needs to be searched, assuming this is

because the first occurrence of Otto cycle combustion process against the backdrop of the volume of gas entering the

combustion chamber.

Characteristics of gas volume V (m3/kg) is influenced by the universal gas constant R (kg.m / kg.K), the initial airtemperature T (K), the initial air pressure P (kg / m).

Dispalcement

Displacement describe how much gas the maximum capacity that can be inserted into the combustion chamber /

cylinder chamber. Variables that affect the volume VL step (m3) is the cylinder diameter D (mm), step length /

height of the cylinder L (mm).


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The Number Of Loads Per Cycle Ideal

Amount of charge per cycle BM (kg) is known aspcomparative capacity of gas storage space VL to the volume of

gas that is inserted V. So the equation as follows.

Indeed the amount of charge per cycle Ideal

In addition to BM, the number of actual charge per cycle ideal BMS (kg) were also calculated by including the

variable efficiency volumetris V (%) as follows.

BMS can also be more accurate by including variables and air fuel ratio AFR is ideal in a certain round, so the

formula becomes as follows.

Efficiency Thermic

Thermic efficiency th (%) was successfully converted into heat power. Variables that influence the compression

ratio and the constants k based value octane fuel (gasoline).

= ...(1.6)

Efficiency Volumetris

Volumetris efficiency V (%) is to calculate the comparison value of gas revenues that should go with a gas thatactually managed to put the piston during the suction step. Some of the variables that influence it, among others,

effective power in each round of Ne (PS), fuel calorific value Qc (kcal/kg), the combustion efficiency pemb (%),

mechanical efficiency m (%), round n (rpm), BMS and th.

V =

Step Entered / Step Suction of Piston

In this step the piston moves from top dead point (TDC) to bottom dead point (TMB) and a decrease in pressure

occurs due to enlargement of the volume of the cylinder, so the final pressure suction step was sought by thefollowing formula.

P1= Po . V ...(1.8)

with: P1 = pressure suction end of step (kg/m2)

Po = pressure suction first step (kg/m2)


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End Temperature of Fuel and Air Inclusion

In the actual circumstances that enter into the cylinder to absorb heat from the valves, cylinder walls, as well as other

hot motor parts. To find the final temperature of the fuel and air intake, we use the formula.

with:

T0 = Temperature of income, (K)

T = Temperature Preheating (00-20), taken 10

Tres = temperature of gas residues (900 - 1000 K), taken 950 K

res = coefficient of residual gas

Entering the number of Air Cylinders At Step Suction

aG = d. d. 2. g. Pd.o ...(1.10)with :

d = Venturi cross-sectional area, m2= .. (dven)2

o = Density (density) of air at the time of entry into the carburetor, kg/m3The amount of air density can be obtained from the relationship.

P. V = G. R. T

or :

P0=o.R0. T0

Number of Fuel Entering Suction Cylinders At Step

In addition to air, which is calculated is the amount of fuel used in combustion processes, Gf (kg /hr). While the fuelused is of premium gasoline with octane number 88. Numbers suggest the percentage volume of octane iso-octane

and normal heptane, ie 88% of the volume of iso-octane and 12% by volume of normal heptane.

fG = f . aG ...(1.11)

with:

f = fuel mixture ratio of air / AFR

fG = Number of fuel into the cylinder, kg / hr.

Number of Fuel and Air Mixture Entering Suction Cylinders At Step

The amount of fuel and air mixture G(kg / h) is the sum of aG and fG , as follows.

G = fG + aG ...(1.12)

Constant Fuel Mix and Air mR

Price mR (kg.m / kg.K) can be searched.

...(1.13)


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Compression Step of Piston

In this process a mixture of fuel and compressed air, resulting in the addition of pressure and temperature. In thiscompression process is considered adiabatic, ie no heat income and expenditure. For the calculations in this step,

apply the relationship.

P.kV = Constant and P .

kV = C

P1.kV1 = P 2.

kV2

So, P2= (r)k. P 1 ...(1.14)

with:P2 = Pressure end of the compression stroke (kg/m2)

V2 = Volume of cylinder on the compression stroke (kg/m2)

r = compression ratio

Final Step Temperature Compression

In addition to pressure, the final temperature T2 compression step (K) in calculation with the following formula.

T1.V1k-1

= T2.V2k-1

So, T2= (r)k. T 1 ...(1.15)

with:

T2 = temperature of the end of the compression stroke (kg/m2)

Step / process of burning

In this process occurs income heat, Qm (kcal / h) from the burning fuel-air in the cylinder. Inclusion of this heatoccurs in the volume remains, apply a relationship.

mO = fG .Qc ...(1.16)atau:

mO = G. vC . (T3 T2)

By entering the above formulas can be obtained value of the final temperature T3(K) and pressure at the end of theburning of P3(K).

...(1.17)

with:Cv = Specific heat of combustion at constant volume for

Cv = CPM - Rm / J

J = unit modifier factor is 427 kgm / kcal

T3= temperature during combustion (K)

P3= P2. T3/T2 ...(1.18)

with:P3 = pressure combustion (kg/m2).

Ekspansion Step of Piston

In this step does not happen income and expenditure of heat, then the work is considered adiabatic. Thus Q= 0 and

S= 0. The amount of pressure at the end of the expansion step P4 ) is.


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dengan :

Thus,

P4= . P3 ...(1.19)

Temperatures in Final Expansion Step

...(1.20)

Step Process Heat Expenditure

After the piston reaches QK TMB issued a number of heat (kcal / h) of the cylinder. This process takes place atconstant volume. The amount of heat released is.

Qk = G . Cv . (T4 T1) ...(1.21)

The next step in the process of waste, air and fuel mixture from the combustion products are pushed out by a pistonthat moves from the TMB to the TDC at constant pressure.

The amount of motor fuel efficiency of Otto cycle, (%) is.

4. Crank Shaft Torque Gas Formulation

Figure 1.2 The relationship of geometry slider crank mechanism

From Figure 1.2 has made the formulation of the force due to gas pressure in the combustion gases from thecombustion chamber on the top of the piston. In Figure 1.2 style denoted Fg gas, gas pressure Pg, Ap is the surfacearea of the piston top, and B is the diameter of the cylinder, so that.

Fg= - P g. A p. I^ ...(2.1)

Ap= /4 B2 ...(2.2)

Fg = - /4 PgB2i ^ ...(2.3)

with:

= angular speed

q = Position the piston in the x-axis


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2= crank angle motion

= angle degrees crank

s = length of piston arm

u = Long arm of the piston against the angle

x = distance to the pin crank piston pint = Time

Fg = Force of gas

Pg= Gas pressureAp= Surface area of piston

I^= distance to the pin crank piston pin

B = Diameter of cylinder

Negative sign is due to the orientation of the election machinery in the coordinate system as in Figure 1.2. Gaspressure Pg is stated here is the function of crank angle . T and caused by the presence of symptoms of the

thermodynamic machine. Torque gas that occurs is caused by the gas works in the arm to the crankshaft O2 moment,

this moment arm varies from zero to maximum in accordance with the rotation of the crank. Force distribution on the

top surface of piston gas settled into a single force acting through the center of mass of the connection 4 at the free-body diagram of Figure 1.3 below.

Figure 1.3 free-body diagrams.

Without deriving the formulation of appropriate Figure 1.2, the final formulation of the torque generated gas as

follows.

Tg21= F gr sin cos^ ...(2.3)

with: Tgis torque of gas.

5. Designing Modeling Torque Gas Crank Shaft

Figure 1.4 Block diagram of motor fuel system simulator 4 steps.

When drawing attention to 1.4, the motor fuel at motor fuel system simulator 4 steps formed by the completeness of

the space component of the operation of piston cylinder and completeness as a pump that works up and down the


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conditions of gas mixture of fuel and air, crank shaft as the driving force early mediation of coupling the starter

motor , and the valves that regulate the entry and exit mechanism is a mixture of fuel gas and combustion gases.

Workflow systems that make up the torque according to Figure 1.4 is the fuel and air flowing into the carburetor andstored and mixed to form for ease of combustion gases when the combustion chamber. Vacuum arrangement

governed by Idle Speed Air Adjusting Screw (ISAS), while the ratio of the mixture of fuel and air / Air Fuel Ratio

(AFR) is set by the Idle Mixture Adjusting Screw (IMAS).

Gas flowing from the carburetor into the cylinder chamber through the intake manifold and the amount of gas into

the cylinder intake valve is determined by the job. Gas is successfully inserted into the cylinder and then compressedby the piston, 80-100 before Top Dead Point (TMA) gas burned in the combustion chamber by a spark plug (ignition

system) in a closed state of intake valve and exhaust valve closing all, the result is the form of an explosion that

drives the piston downward. The explosion can be called a style of gas, then rotate the crankshaft or generating

torque at the crankshaft. Henceforth, the crankshaft serves to save energy for the ability of the piston starts moving

back to their circuitry.

Flowchart Modeling Gas Torque Crank Shaft lokks in Figure 1.5.

6. Implementation

In this chapter, implementation, testing and discussion of results from the cycle efficiency calculations and modeling

of the crankshaft torque. To run this simulator, it takes the computer with the following minimum hardwarespecifications:

a. CPU / Laptop, 1.7 GHz Processor i386.

b. 256 MB of memory.

c. VGA 128 MB.

d. 200 MB hard drive free space.e. Keyboard and mouse.

Figure 1.5 Flowchart design modeling gas torque of the crankshaft.


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The software supports the visualization made is Blender 2.49b for graphics, while the programming language used is

Python 2.6.2.

Crankshaft torque modeling step is done as follows.a. The study of literature on shape and dimensions of the crankshaft.

b. Visually observe the physical form of the original crankshaft and how it works according to the 4K engine type

OHV 4-cylinder.c. Determining the dimensions of the crankshaft

d. Perform mathematical calculations movement / torque of the crankshaft

e. Make observations to the model form and movement of the crankshaft torque.

Implementation of the crankshaft torque to perform mathematical calculations by 3:14 the following equation.

Baru! Tahan tombol shift, dan seret kata di atas untuk mengatur ulang. Singkirkan

7. Testing

Functional testing of crank shafts.This test aims to determine whether the application is made in accordance with the design concept. The data was

collected observations of these functions in applications, application forms are made by Guttman scale. Here are the

results of the testing function.

Testing Against User

This test aims to determine the suitability of the design concept of modeling the crankshaft and torque / movement of

the crankshaft in accordance with reality. Techniques of data collection are done by using a questionnaire with aLikert scale. This scale is used to measure the opinions and perceptions of a person or group of people about the

products made.

Training participants Lightweight Vehicle Engineering department is projecting a 3D simulator users combustion 4

steps. Participants who have been through training are the main condition know the basic competencies of

automotive engineering. The number of respondents of this research is 25 people. Activities conducted as follows.

a. Explains the notion of torque.

b. Explaining the workings of the crankshaft.c. Explaining about the torque on the crankshaft.

d. Explaining the gas torque of the crankshaft.

e. Shows a simulation model of the crankshaft torque.f. Respondents watched as he filled the questionnaire.

Here are the results of testing against the user.

Tg21= Fgr sin cos ^

Konvert in Blender 2.49b :own.hasil= own.tambah * own.putaran +float(mydata1[2])


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Likert scale calculations performed by multiplying the existing scale, then summed and compared with the ideal

score. Format and sample questionnaires are in the Appendix. Based on the use of Likert scale scores could not

agree more ideal is 125, it was calculated as follows.

a. Strongly disagree (1x25 = 25).b. Disagree (2x25 = 50).

c. Hesitation (3x25 = 75).d. Agree (4x25 = 100).

e. Strongly agree (5x25 = 125).

From the processing of data on the average score of modeling gas torque of the crankshaft are 106.04. Based on the

average score of the respondents strongly agreed that modeling could inform the actual torque of the crankshaft ofthe maximum score could not agree more than 125.

Testing Effect of Combustion Pressure (P3) of torque Gas (Tg)


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Crank Shaft Torque Testing of Gas Carburetor Edit

Crankshaft torque testing gas is the measured torque values due to variations in the manipulation of the IMAS-ISAS

in the carburetor. Test results can be viewed as follows.

Figure 1.6 IMAS-ISAS has not been played, then the torque = 0 (dead motor fuel).

Figure 1.7 IMAS-ISAS rotated 200clockwise, the torque value = 0.00400 (motor fuel has been moving slowly).


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Figure 1.8 IMAS-ISAS 450rotated clockwise, the torque value = 0.03600 (motor fuel to move faster).

Figure 1.9 IMAS-ISAS 850rotated clockwise, the torque value = 0.030600 (motor fuel to move faster).

Figure 1.10 1950IMAS-ISAS rotated clockwise, the torque value = 0.167200 (motor fuel moves very fast).

Figure 1.11 2700IMAS-ISAS rotated clockwise, the torque value = 0.420900 (motor fuels increasingly moving very

fast).


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Figure 1.12 IMAS-ISAS 450 rotated counter-clockwise, the torque = 0 (dead motor fuel).

Figure 1.13 Test results from the influence of IMAS-ISAS manipulation of the gas torque of the crankshaft.

Based on Figure 1.13, it can be conclude that the greater degree swivel on the IMAS-ISAS then the greater the

torque value, thus the greater the torque that causes the rotational speed of the crankshaft is increasing rapidly.

Crank Shaft Torque Testing of Gas Distributors Edit

Figure 1.14-timer button ignition in 100before TDC torque value = 0.010500.


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Figure 1.15-timer button ignition at 80before TDC torque value = 0.080500.

Figure 1.16-timer button ignition at 50before TDC torque value = 0.130500.

Figure 1.17 Test results from the influence of manipulation of the controls ignition timing of the gas torque of thecrankshaft.

Based on Figure 1.17, it can be conclude that the greater value of degree turn the ignition timing so the greater the

torque value, thus the greater the torque that causes the rotational speed of the crankshaft is increasing rapidly.

8. Closing

Based on the testing of the simulation program, so in this study can be made the following conclusion.

1. Visualization in the Otto cycle combustion engineering simulator fourth step is the research thesis which discusses

the visualization in 3D of the crankshaft mechanism cooperating with the piston mechanism, the valve

mechanism and several other systems to meet the working principle of 4 stroke motor fuel in Otto cycle .Visualization Otto cycle provides visualization of the work cycle that applies in motor fuel type petrol 4 stroke

motor, that is visualizing the piston to 4 (four) steps translation movement / back and forth and visualization of

the crankshaft to two (2) rotation / rounds (7200) for generate one-time effort (force / power). In addition, Otto


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visualization include visualization of the process gas fuel mixture that is chemically burned into the gas-style gas

producing mechanical torque.

2. Visualization Otto cycle in the study of this thesis was built by the calculation of thermodynamic calculations thatanalyze the Otto cycle combustion pressure value which is then termed as the style of gas and also built by

mathematical modeling that is by modeling the gas torque of the crankshaft which calculates the gas torque.

Mathematical calculations are modeled into the shape of the crankshaft rotary motion relating to the mechanismof piston and valve mechanism. Implementation is then tested the function testing and user trials. Function testing

was found that all the functions of the crankshaft torque modeling appropriate design concept. User test results

indicate the respondents strongly agreed, modeling can inform the shape and workings of the crank shaft torquesystem of Otto cycle as the actual (average scores of 106.04 the maximum score is 125).

9. Bibliography

[1] Arismunandar, Wiranto (1988), Penggerak Mula (Motor Bakar Torak), Institut Teknologi Bandung, Bandung,Indonesia.

[2] Bell, A. Graham (1981), Performance Tuning in Theory and Practise Four Stroke, First Edition. Haynes

Publishing, United of Kingdom.[3] Bell, A. Graham (2006), Four Stroke Performance Tuning, Third Edition. Haynes Publishing, United of

Kingdom.[4] C.F, Taylor (1989),Internal Combustion Engine in Theory and Practise,MIT Press, Unied states of America.

[5] D.Wood, Bernard (1981),Applications of Thermodynamics, Second Edition, Addisson-Wesley Publishing, NewYork, United States of America.

[6] Ferry, Muhammmad Djatmika (1996), Perhitungan Torsi Gas Motor Pembakaran Dalam,Puslitbang Telimek

LIPI, Bandung, Indonesia.

[7] J. Moran, Michael and Shapiro, H.N. (1993), Fundamentals Of Engineering Thermodynamics, Second Edition,

John Wiiley and Son, United States of America.[8] John B, Heywood (1988), Internal Combustion Engine Fundamentals, McGraw-Hill Inc, United States of

America.[9] Khovakh, M. (1967),Motor Vehicle Engines, General Edition, MIR Publisher, Moscow, Rusia.

[10] Khurmi, R.S. (1995) A Text Book of Mechanical Technology, Thermal Engineering. S. Chand & Company

LTD.

[11] M.M, Abbott and Van Ness, H.C. (1981), Theory and Problems of Thermodynamics,Schaums Ouline SeriesMcGraw-Hill Inc, United States of America.

[12] Toyota, PT. (1985),Dasar-dasar Automobil, PT Toyota Astra Motor, Jakarta, Indonesia.

[13] Robert, Norton (1992),Design of Machinary, McGraw-Hill Inc, United states of America.

[14] Sen, S.P. (1980),Internal Combustion Engine Theory and Practise, Khana Publisher Delhi, India.

[15] Singh, V.P. (2009), System Modeling and Simulation, New Age International (P) Ltd, India.[16] Sridadi, Bambang (2009), Pemodelan dan simulasi Sistem (Teori, Aplikasi, dan Contoh Program dalam

Bahasa C), Informatika Bandung, Indonesia.

[17] Swisscontact (1997), Analisa Kinerja Motor Bensin berdasarkan Hasil Uji Emisi, Swisscontact-Clean AirProject, Jakarta.


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VIRTUAL INTERACTION ON AUGMENTED REALITY FOR

EDUCATION WITH NONPARAMETRIC BELIEF PROPAGATION

ALGORITHM

Yoki Ariyana*#1

, Aciek Ida Wuryandari#2

*Center of Development and Empowerment Teachers and Education Personnel in Science

(PPPPTK IPA Bandung)#School of Electrical Engineering and Informatics

Institut Teknologi Bandung - [email protected]

[email protected]

ABSTRACT

Information technology currently supports the development of human interaction with virtualenvironment, this development will continue in the form of Human Computer Interaction (HCI). In this

study, we develop a new technology, how the virtual environment 3D computer should be able to recognize

human hand as part as virtual object, so it can interact with virtual environment for education.

This research is using Nonparametric Belief Propagation (NBP) as a tracker in virtual interaction by using

Augmented Reality (AR), the problem that arise in AR is how to read marker, so it can display a virtual

object that has been computed before, basically NBP is used to read the geometry model of human hand,

then the result from the processing of the human hand model geometry is used as a marker, so it can

interact with a virtual environment on AR as one of the HCI model implementation. This process is

intended for the movement of human hands that have been read as a virtual object can communicate

virtually using image processing.

KeywordsHuman Computer Interaction, Augmented Reality, AR-Education, NBP, Virtual Interaction

1. INTRODUCTION

Augmented Reality (AR) is to merge the real world and virtual environment. Virtual object added into real world inorder to improve or to add more information from the object. AR is a computer-generated data integration with the

real world, which among others can be done with computer graphics rendering on a real-time footage. AR can beused for many things, such as displaying a mobile directions to head-up display, in the medical field, the AR may

help doctors to insert information on a patient's medical record (such as x-ray result from the patients), or to

reconstruct the old buildings and historic as reality which can be seen at present time. Virtual Reality (VR) was

developed using a concept that actually use the environment which are engineered in such a way that resembles the

real world.AR and VR provide features that complement each other from the results displayed by the computer-generated

images to provide another experience for the user. The differences would be very visible at the time of AR displaysthe real world that actually taken from real-time environment where the real environment are given an additional

reality the result of image processing performed by the computer. Combined real-world and computer engineeringimage that is currently being developed by several research at several universities such as Columbia University and

the University of South Australia.

To do such a thing, someone can connect a video camera to the computer and create a virtual image on a digitalpaper (paper that has been contained images that can be read by a computer camera as a marker) or other objects that

have been determined so that the camera can be recognized by computer or better known on AR as the HMD (HeadMounted Display), so that the user can see the virtual object on paper or augmented objects that have been

determined, on the computer screen.


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Figure.1 AR System in generally.

HMD introduced for the first time in 1968 and VR are the focus area of its development, there are some similarities,

the problems that arise in research on VR and AR but not dependent on the physical environment which then can be

displayed on the monitor or the projector, the VR research, researchers engineered environments has a limited to

using a computer and thus require substantial resources to produce large environments, distinction from AR that usesa real environment as a basis and added to computer engineering, so researchers were not stuck with how to develop

a virtual environment, but they are use the real environment in real time.

Figure. 2 Augmented reality scheme.

On development, the position of AR and VR can be combined and it called Mixed Reality (MR) and can be seen in

the reality-virtually continuum, where there is a relationship between the physical environment to virtual

environment, reality-virtually continuum can be seen in Figure. 3. Below.

Figure. 3. Reality-virtually continuum

Sample applications that use the AR is the game and some applications to architecture, the AR-based game allows

players to interact directly with their environment so make the distinct impression more viscous. AR is not only usingtwo-dimensional (2D) but also three-dimensional (3D) so that the object looks more real with a dimensionless 3.

Real world in everyday life has grown much in line with the development of technology in the field of IT. Virtual

environment at this time also developed in accordance with the rapid development of the IT world, a virtualenvironment used by the IT community in many ways. This research focuses on human interaction to the virtual

environment that is generally known as the HCI, virtual interaction is included into the HCI because the virtualenvironment generated by computers and humans as users or developers of computer systems for humans to interact

with virtual environments.Humans have a desire to interact with a virtual environment in various ways, in a most simple but very efficient. It

not like in real life that can be perceived by the human sense of taste held since birth, by interacting with the virtual

environment of human imagination with all it has to be able to feel what was in the virtual environment and interact

with the world. Much interaction is currently being developed, with interaction via sound, visual, until the brain

waves can be performed by a virtual environment, interacting with the feeling is more prevalent, although this

interaction is one more to how the interaction took place between people from the real world with the virtual objects

that are generated through computer engineering.


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Communication with the virtual environment today is widely developed in many things, this study wanted to knowhow real human interaction with the virtual environment by using the gesture recognition on the part of the human

body (in this case is a hand).3D computer environment need to recognize the human hand as a virtual object so that virtual objects can interact

with virtual environments, in this process required an algorithm to recognize the movement of human hands that willinteract with the virtual environment. This process in the form of algorithms for the movement of the human hand

can be read as an object that can also communicate with the virtual environment by using image processing thatrequire a reliable computer performance.

HCI is a study in which the relationship between humans and computing technology and how computers are

designed for easy to use by human beings, more practical and more intuitive. HCI emphasizes how human interactionon computing and design interface computer technology.

HCI is defined by ACM SIGCHI [11] as "a discipline concerned with the design, evaluation, and implementation ofcomputing systems for human use and with the study of major phenomena surrounding them"

Today HCI developed rapidly by the designers who continue to modify and make the development of HCI research.

Human interaction in this case has been developed into multimodal input of humans as a center of technology that is

growing.

The development of HCI has developed into virtual interactions (Human Virtual Environment Interaction - HVEI),on HVEI, humans interact with virtual environment using technology developed by HCI, HVEI becoming a trend

with the development of HCI research models, HVEI HCI research is how humans interact with virtual environmentand communicate with the virtual world and give effect to this virtual environment so that the virtual environment to

respond to human interaction.

2. HUMANCOMPUTERINTERACTION

HCI is a discipline of science that focuses on the design, evaluation, and implementation of the interaction of

computing systems for human interests, and supports the development of technologies that benefit the environmentconcerned. Basically there are 4 areas of HCI and all development is to enhance human interaction with computing

systems.a. design of an interactive computing system which focuses on how to design a computing system that is easy to

use, effective and fun so that is basically a how to find solutions in designing new computing.

b. implementation of interactive computing system which focuses on how to produce a knowledge of the

capabilities of technology and ideas about the development potential that can be utilized so that in this section ishow to build applications.

c. Evaluation of interactive computing systems of the discussion focuses on the process whereby data collection

systematically used by users or groups of users that can be used in the environment is concerned; this section

focuses on the use of data collection and data analysis.

d. Studies of how phenomenon discusses issues such as how the introduction of computer system can affect the

work or how the reactions that arise when humans communicate with each other with machines, in this section

focus on how your study of the development of the human relationship with machines.Developed much interactive design, interactive design developed consists of the design system and design process.Design system focuses on how to design concepts and models of interaction in interactive computing system, while

design process is how to develop methods and tools of system design. The development of interactive computing

system design with the ever combine multiple input devices of computer systems and models of interaction has been

developed on a virtual model or mobile, these processes are carried out is the result of analysis and design of

interactive computing systems from HCI. Virtual reality is one of rapid development of HCI addition done on amobile form of mass developed by several vendors.

Some of the existing interaction techniques based on the orientation of HCI such as head tracking that allows users to

interact in accordance with the orientation of the human head that can use the full 360-degree angle, so there is no

restriction on head orientation tracking is because humans can use the eye as a sense of vision that can look to 360

degrees with the help of human head and body movement, distinct with head tracking with the active zone, the pointhere is how the human orientation is limited by certain zones that have been determined in a computational system.

Other interaction-based orientation is with the joystick and trackball, joystick allows interactions can be easily used

for continuous or rapid rotation, but in contrast with the trackball is good and easy to use on the interactions that need

precision and accuracy to rotate.

Other techniques in computing interaction is the base of movement, position tracking which actually is a combination

of using the joystick, trackball that both is how objects can be moved by using two tools, how objects can interacteasily using the joystick or trackball, but the difference is the focus on speed and accuracy. Generated virtual world is

the result of computing systems and interaction resulting in the virtual world either in virtual or augmented reality is


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how that movement can be read as part of interaction in virtual computing world. Another thing in computinginteraction technique is to acting, there are two known acting in the virtual world of HCI, which is a virtual hand that

uses tracking systems such as mobile tracking system that serves as a means of human interaction with virtual objectsthat have been previously Computed using the human hand as a tool input. Next is a virtual pointer, the virtual

pointer is also a tracking system but the difference is the tracking system is using another tool such as pointer, thepointer used these interactions as a determinant of the location of interaction on objects that already exist.

3. HUMANINTERACTION

Humans instinctively interact with their environment, either directly or indirectly use the tool or tools that areconsidered useful for humans; there are several categories of human interaction in conjunction with HCI and HVEI.

a. Real World Interaction

Figure. 4 Human Interaction in Real World.

In the picture above can be seen that human beings interact directly to real objects in the environment of human

being (regardless of how the interaction took place, using tools or not). Humans actively interact directly againstthe object on the environment and assume that the object is useful for humans.

b. Real-world interactions that lead to the virtual effects

Figure. 5 Human Interaction computed to virtual world.

In the picture above can be seen that human beings interact directly on a real object, and then cause effects on

the virtual world that has gone through the process of computing. Research conducted by Ausgefuhrt[2]is oneform of examples from real-world interaction virtual effects, as an example in the Figure below.

Source : ( )

Figure. 6 a) generate effect to b), and c) rendering result from d).

c. Virtual Interaction

Figure. 7 Human virtual interaction.


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Virtual interaction by virtual human on the environment and the direct effect of a virtual environment with thechange of location, or node in a virtual environment. Picture below is an example of interaction with virtual

environment.

Source : ( )

Figure. 8. Virtual Geometry.

4. NONPARAMETRIC BELIEF PROPAGATIONNBP has the aim to solve existing problems in graphical modeling with continuous variables, highdimensional and non-Gaussian. NBP using two approaches, first, for graphs with cycles, no form a tree,

but an update of iterations as in Belief Propagation (BP). This is very beneficial because it reduces thedimensions of the spaces where we have to conclude distribution. Second, the update message onalgorithms specifically adapted to the graph that contains continuously, and non-Gaussian. The main

difficulty is in determining an efficient method to combine information provided by several variables /

nodes that are most closely related. NBP algorithm can be applied to free and structured charts that containa variety of possible functions; the algorithm is effectively used as a method that is used as a filter elementthat is much broader than computer vision problems.

NBP associated with Hidden Markov Models (HMF) as a model for the development of the NBP, HMF

has an important role in computational algorithms NBP.

5. AUGMENTEDREALITYFOREDUCATIONAR on education much can be developed. One of them recognizes the objects that in fact difficult tointroduce or merely a concept and image as human organs and their function as student learning materials

in secondary schools and in higher education circles, or practicum which is harmful to students. AR ispotentially developed in education so that a variety of learning resources can be optimized and the use of

new technologies in the IT field.As in Figure 8, Virtual Geometry [8]. Is one form of learning in the form of AR, the student or studentsusing a virtual environment that is generated by the computer so it can learn geometry directly. In this

lesson students use the tools that support the AR such as HMD and the pen tool. The resulting image is avirtual form of object actual geometry.

AR in education such as that developed by Columbia University is in terms of taxonomy of plants by

identifying the form of leaves on the skewer with plant taxonomic data that has been stored previously,and computationally processed by computer vision-based process, so there is information about the plantin question in real time.

Source : ( )

Figure. 9 AR plant Taxonomy [14].


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6. RELATEDRESEARCH

Game using the AR now is widely developed, such as ARQuake developed by the University of South Australia[4],The Invisible Train, developed by Vienna University of Technology, Cows Vs. Aliens developed by the Graz

University of Technology, developed by AR Tennis Henrysson, Billinghurst & Ollila, 2006, or even the Art ofDefense, developed by the Augmented Environments Lab greater emphasis on the entertainment side alone, thepicture below is one of the game using AR technology, Racing game developed by the Department of Computer

Science - Columbia University[14], AR Ping-pong which was developed by the Computer Vision Laboratory, ETHZurich, Switzerland. Billiards game developed by the Department of Innovation Engineering, Salento University of

Lecce - Itayl. While in education, developed the AR is in the field of Botanical Species Identification by ColumbiaUniversity[14]. Then at the same university is Designing a Mobile User Interface for Automated Species

Identification and Interaction and Presentation Techniques for Shake Menus in Tangible Augmented Reality. The

"Magic Book" was developed by the Centre for Children's Literature, Christchurch College of Education.

REFERENCESAaron Stafford, The God-Like Interaction Framework: Tools And Techniques For Communicating In Mixed-Space

Collaboration, Adelaide, 2008.

Ausgefuhrt, Ubiquitous Animated Agents for Augmented Reality, Viena University of Technology, 2006Brad A. Myers,A Brief History Of Human Computer Interaction Technology, Human Computer Interaction Institute,

School Of Computer Science, Carnegie Mellon University, 1996.Bruce Thomas, Ben Close, John Donoghue, John Squires, Phillip De Bondi, Michael Morris, Wayne Piekarski,

ARQuake: An Outdoor/Indoor Augmented Reality First Person Application School of Computer andInformation Science, Universit yof South Australia, 2000.

Doug A. Bowman, Jian Chen, Chadwick A. Wingrave, John Lucas, Andrew Ray, Nicholas F. Polys, Qing Li, YoncaHaciahmetoglu, Ji-Sun Kim, Seonho Kim, Robert Boehringer, And Tao Ni , New Directions In 3D User

Interfaces, Centre For Human-Computer Interaction , The International Journal Of Virtual Reality, 2006.

Francesca MORGANTI, Virtual Interaction In Cognitive Neuropsychology, Centre For Cognitive Science,Department Of Psychology, University Of Torino, Italy, 2006.

Georg Klein, Kings College, Visual Tracking For Augmented Reality, University Of Canbridge, 2006Mag. Hannes Kaufmann, Geometry Education With Augmented Reality, 2004

Mary Pietrowicz, Robert E. Mcgrath, Transforming Human Interaction With Virtual environments, University OfIllinois At Urbana-Champaign,2009.

Markus Schlattmann Tanin Na Nakorn Reinhard Klein, 3D Interaction Techniques For 6 DOF Markerless Hand-Tracking, Universitt Bonn, Germany,

Majlinda Fetaji, Suzana Loskoska, Bekim Fetaji, Mirlinda Ebibi, Investigating Human Computer Interaction IssuesIn Designing Efficient Virtual Learning Environments, Sofia, Bulgaria, 2007

Reinhold Scherer, Mike Chung, Johnathan Lyon, Willy Cheung, And Rajesh P. N. Rao,Interaction With Virtual And

Augmented Reality Environments Using Non-Invasive Brain-Computer Interfacing. Vanice Italy, 2010Sren Lenman, Lars Bretzner, Bjrn Eiderbck, Computer Vision Based Recognition of Hand Gestures for Human-

Computer Interaction, Department Of Numerical Analysis And Computer Science KTH, 2002.

Sean White, David Feng, Steven Feiner, Interaction and Presentation Techniques for Shake Menus in Tangible

Augmented Reality, Columbia University, 2009.Thomas Pederson, From Conceptual Links To Causal Relations Physical-Virtual Artefacts In Mixed-Reality Space,

Department Of Computing Science, Ume University, 2003.

Olivier Bernier, Pascal Cheung-Mon-Chan, Arnaud Bouguet, Fast Nonparametric Belief Propagation For Real-TimeStereo Articulated Body Tracking, France, 2009.

Ohan Oda Levi J. Lister Sean White Steven Feiner, Developing an Augmented Reality Racing Game, Department of

Computer Science, Columbia University, New York, 2008.Vladimir Savic, AdriAn PoblaciOn, Santiago Zazo And Mariano GarcIa ,An Experimental Study Of RSS-Based

Indoor Localization Using Nonparametric Belief Propagation Based On Spanning Trees, Signal Processing

Applications Group, Polytechnic University Of Madrid, 2010.

Wayne Piekarski, Interactive 3d Modelling In Outdoor Augmented Reality Worlds, University Of South Australia,

2004.

Wouter Alexander De Landgraaf, Interaction between Users and Augmented Reality Systems: Human-ComputerInteraction Of The Future, Vrije Universiteit Amsterdam, 2004.


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ABSTRACT

Zoopedia is an application that can provide information about animals by displaying a variety of

visualizations, such as texts, images, videos, and simulations using 3-dimensional objects (3D) which allow it

to interact with the users. Zoopedia application is more focused on developing simulations of animal behavior

which is expected by the visualization of this simulation so that the user can obtain a more tangible

experience of animal behavior. To obtain a realistic simulation quality, virtual animal agent which is an actor

in the simulation should be made as identical as possible with the actual animal. In a game or an agent

simulation that behaves in a virtual environment that is not controlled by the user, usually called Non

Playable Character (NPC). NPC behavior can provide an overview of a certain situation or condition in a

simulation.

This study aims to design and implement tiger NPC behavior in Zoopedia application by using Finite State

Mechine (FSM) method for decision making. NPC tiger behavior is designed to provide the closest to the

actual behavior, then added a few attributes, such as energy, stamina and speed. Behaviors designed in this

study includes deterministic and nondeterministic behaviors.

The results obtained show that in general the NPC has behaved according to the design. Although the

behavior of the NPC in this simulation has given a good impression on the users, this simulation still needs

further development so that the simulation produced will be more dynamic. Further, it can be developed into

more nondeterministic behaviors and also possible other algorithms that correspond to the behavior of

animals that will be developed.

Keywords: Zoopedia, simulation, NPC, FSM, deterministic, nondeterministic.

1 INTRODUCTION

With current technological advancements, a variety of devices can be developed as a means or mediumfor people to be able to recognize the wealth of animal species that exist in Indonesia. One is through themedium of the Internet to inform the kinds of animals that exist in Indonesia. However the information

conveyed by the media, such as the information conveyed by Wikipedia are in the form of text, imagesand video.

Therefore Zoopedia application is developed not only to provide some information in addition to text,images and video, but also a more tangible experience for users. One is to develop simulation models ofanimal behavior.

Animals behaviour have long been the subject study of zoologists and ethologists, and have recentlyhelped inspiring the emerging research discipline of artificial life.This Artificial life in computer graphics

has spawned several research and development principals. The artificial life approach has provedespecially effective for advanced animation. Techniques are now available for realistically modeling andanimating plants, animals, and humans. Behavioral modeling is a major trend in the motion picture specialeffects industry. The relentless increase in computational Power is drawing the attention of researchersand practitioners to synthetic characters for interactive games.

To enable an animal behavior model in a simulated game,an Artificial Intelligence needs to be applied.Application of artificial intelligence to design certain agent to be able to move in a realistic computersimulation game is one of the challenges

[5]. Artificial intelligence is a technology which simulates human

intelligence and tries to solve problems using computers to mimic how humans solve quickly their

Disign and Implementation of Zoopedia:

Behaviour of Non Playable Character (NPC) of Tiger Hunting the Prey

Heri Ahmad Safari1, Agung Harsoyo2, Kuspriyanto3

1School of Electrical Engineering and Informatics, Bandung Institute of Technology

Jalan Ganesha No. 10, Bandung 40132, [email protected]

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problems. Agents that behave in a virtual environment which is not controlled by the user, typically called

as Non Player Charavter (NPC). Based on the above background, the research to be done is to design thebehavior of NPCs in the hunt for prey in the application Zoopedia

2 LITERATUREREVIEW

2.1Non Playable Character (NPC)

NPC model means dynamic objects which are not subordinate to any control of their user and decideby themselves and operate in virtual space. For example, it plays role as an enemy to the PC (PlayableCharacter) or as a supplementary partner which leads the game smoothly in online-games. Fundamentally,

the behavior of NPC is based on the state-transition information and itscontrol structure is defined by thedeveloper. This is an important element which the developers should consider when they draw a plan.Generally, NPC repeats the sense, the thought, and the decision cycle. Fig 2.1.

Source : (Kim, at all, 2006)

Fig 2.1 Behaviour NPC Steps

2.2Artificial Intellegence (AI)

Artificial intelligence (AI) is an effort in computer science specifically intended to create software andhardware which is fully capable of imitating some functions of the human brain, Artificial intelligence isalso a branch of computer science which studies the behavior of automation intelligent [7].

The definition of AI can be grouped into four categories, system which can think just like humans,

system which can act like humans, system which can think rationally, and system which can actrationally

[8].

The main part of the application of AI is knowledge, the understanding of some subject areas which areacquired through education and experience. Knowledge is organized and analized information to be moreeasily understood and can be applied to solve problems and making decision. Knowledge consists of facts,

ideas, theories, procedures, and their relationship to each otherIn certain game or simulation, AI is used to create programs that enable artificial intelligence to NPC.

These intellectual are in the form of different behavior. There are many algorithms of artificial intelligencefor designing NPC models, including the algorithms using finite state machine (FSM), genes and neural

network algorithms, methods, crowds flock to describe behaviour and algorithm A*, which is used topathfinding.

2.3Finite State Machine (FSM)

Finite State Machine (FSM) is one of the most basic and simplest models of AI. FSM is a tool ormodel that has a number of states and can operate the inputs so as to make the transition from one state toanother or causes the output occurs. FSM can only be in state at a time and is a method that can indicate a

characters behavior in a certain simulation and games. Transition in the FSM is obtained from theenvironment or system and then processed in accordance with internal data on the system. The main idea

Step Aktivity

Sense Grasp the situation through sensing the information to behappened in current location from server.

Think Decide the action which coincided with its own role in thesituation.

Act Order servers that do the deed to be selected.

sense

think

act


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event

transition

State

A

State

B

of the FSM is to describe the behavior in several states, making it easier for developers in the early design

stage.The basic idea is, in the FSM, there are several components: state, event, action, and transition. For

more details, see the following picture.

3 DESIGNANDIMPLEMENTATIONS

Zoopedia is an application that can provide information about animals by displaying various

visualizations, such as text, images, video, and modeling using 3-dimensional (3D) objects, which allowsit to interact with users. Zoopedia application emphasizes on the development of simulation of animal

behaviour, due to this visualization, it is hope that users can get a more realistic experience. Thus, thebenefit we can get from Zoopedia applications compared with other similar applications is that in thisapplication, the animals behavior are developed.

3.1Virtual Environment

The virtual environment is an environment where the NPC is located. If it can move from one place toanother in that world, it can be said that the NPC has been sufficiently aware of its environment. In thissimulation, the virtual environment which will be designed is the Gunung Leuser National Park, on LakeLaot Bangko area in the village of Ujung Padang Bakongan South Aceh regency, with an area of about250 ha. Virtual environment will be designed for the simulation is expected to resemble the real

tophography as their natural habitat.

3.2Character Model of NPC

To get a realistic simulation quality, vitual animal which is the actor in this simulation should be made

as realistic character (resembling actual animals). Character model of NPC is a realistic adult male Tiger..

3.3NPC Behaviour

NPC behavior in this simulation is the Tiger's in the hunt for the prey. In this simulation, NPCbehavior is controlled by computers, not the user. But it is expected that its behavior is the same as the

reality. NPC behavior in the hunt for prey is limited to the following behavior: 1) in search of prey; 2) thepursuit of prey; 3) eating the prey; and 4) resting.

3.4NPC Attributes.

To produce a realistic NPC behavior, then the designed NPC has to be equipped with its attributes. Attribute is the value that states the basic level of the NPC to complete the physiology of an agents. Inaccordance with the behavioral model and designed NPC, it impacts on the determination of attributes that

should be obtained by the NPC. These attributes are as follows.

State current input of the system

Event current input of the system

Action the current result output from the events

that occurred at that time.

Transition a transition that connects the two state inthe form of events.

Fig. 2.2 State FSM Chart.

Source: (Graham, 2006)


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1.Energy is the ability to perform activities. Each activity will consume energy. Energy is associated

with the state of hunger and affect the physical state of the characters, such as being tired.2.Stamina is the Endurance of an organism. Endurance is very closely linked to the power in the

movement, such as the Tigers in the pursuit of prey it can only maintain to work at maximum speedonly approximately for 10 m, this means that if the tiger cannot get its prey in 10 m, it ill stop. Thus,

the endurance is related to fatigue.3.The movement is an inherited attribute that is used to determine how far the NPCS can move during

the interval of time. This movement is also known as Speed.

3.5Design Finite State Machine (FSM)

To meet the above design, it is necessary to have methods or programming algorithms. Programmingalgorithms for designing the behavior of the NPC, is Finite State Machine. NPC behavior can berepresented in the form of the state. Complex behavior can be made simple by using state by providingadditional rules in that current state. The use of behavioral state in designing the NPC is considered to

FSM algorithm.In accordance with previous requirements regarding the identification of behavior that should be

owned by the behavior of the NPC when hunting prey, then the state that existed at the NPC when hunting

prey are:1) in search of prey; 2) the pursuit of prey; 3) eating the prey; and 4) resting.

Each State is connected by the transition. Each transition leads from one State to another State(destination State), and each State has a series of related conditions. If the condition of transition are met,the current state changes into the destination state. In a state machine, only the current conditions areconsidered so that not all actions can be achieved. The movement of one state into another state is

triggered by one or more factors. Here is state behaviour of NPC chart.

rest1 search

persuiteat

[hungry1][tired1]

[Lookingatprey][P

reyrunaway]

[Cacthing the prey]

[nothungry]

rest2

[lelah2

]

[hungry2]

Fig. 3.8 State Behaviour of NPC Chart

Current state Transiti on Next state

Black circle Has one transition,

without trigger.[rest 1]

Output action : sitting, sleep,standing.

[rest 1] [hungry1] : hungry [search]Output action: wandering

[search] [tired 1] : tired [rest 2]Output action: sitting, standing


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Current state Transiti on Next state

[rest 2] [hungry 2] : normal

stamina[search]

Output action: wandering

[search] [looking at prey] :looking at prey.

[persuit]

Output action : walking andpersuiting

[persuit] [the prey run away] . [search]Output action : walking,wandering

[search] [looking at prey] : see theprey.

[persuit]Output action: persuiting.

[persuit] [tired2] : stamina

decrease[rest 2]

Output action: standing, sitting.

[rest 2] [hungry 2] : stamina

normal.[search]

Output action: wandering.

[search] [looking at prey] :looking at prey.

[persuit]Output action: persuiting.

[persuit] [catching the prey] [eat]

Output action: eating

[eat] [not hungry] [rest 1]Output action: sitting, sleep

4.RESULTSANDDISCUSSIONS

NPC tiger behavior can be divided into two, namely deterministic and nondeterministic behavior.Deterministic behavior, includes behavior in NPC breaks, and meals. While nondeterministic behavior is,

ie when it is looking for prey and chase prey.

Fig. 4.1 (a) seacrhing ; (b) persuiting; (c) eating

Fig. 4.1 shows behavior of NPC of tiger acting according to the attributes value.Giving to the NPC attributes can affect the behavior of NPCs in making decisions. For example, when

NPC of tiger pursuing the prey. Stamina of NPC of tiger will be reduced. So that he will run more slowly(speed decreases). If the prey not overtaken he will take decision to rest, even though he was hungry.

(a) (b) (c)


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5.CONCLUTION

In this study, it has been designed and implemented NPC behavior in tiger hunting its prey. The testresults shows the following result:

1. The use of 3D objects in an application Zoopedia provides a realistic visual effects on-screen

simulation.2. The behavior in this simulation can be categorized into two, namely deterministic behavior

(standing, sitting, sleeping) and non-deterministic behavior (looking for prey).3.

The Finite State Machine (FSM) method is very effective methods used to model the behavior ofthe NPC. Because, with this FSM method, teh NPC behavior can be decomposed into several states.

so that FSM methods will be easy to control the behavior of the NPC, when the behavior of theNPC is not in accordance with the actual behavior.

4. The addition of the attributes of energy, stamina and speed on the behavior of NPC has provided a

more realistic effect on the behavior of NPC.

REFERENCE

Broug, David, Seeman, Glenn. (2004).AI for game Developers, Oreally, Plano, Texas.Craig, W., Reynolds, Steering Behaviors For Autonomous Characters, Sony Computer Entertainment

America, Boulevard, CaliforniaDemetri, T.( 1999).Artificial Life for Computer Graphics, Vol. 8, pp. 1-42.

Graham. (2006).Intelligent NPC, Simulation, and Gamming, Vol. 37 no. 3 339-349,Kim, Chong-Han, Jeong, Seung-Moon., Hur, Gi-Teak., and Kim, Byung-Gi. (2006).Verification of FSM

Using Attributes Definition of NPCs Models, International Journal of Computer Science and NetworkSecurity.

Sandi Setiawan. (1993).Artificial Intelligence, Penerbit Andi Offset Yogyakarta, Edisi pertama.Stuart. J., Russel, Norving Peter. (1995). Artificial Intelligence a Modern Aproach, Emhlewood Cliffs,

New Jersey.

Xiaoyuan Tu.(1996).Artificial Animals for Computer Animation: Biomechanics, Locomotion, Perception,and Behavior,pp. 1-50.


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PLAGIARISM DETECTION SYSTEM DESIGN FOR PROGRAMMINGASSIGNMENT IN VIRTUAL CLASSROOM BASE ON MOODLE

Dewi Tresnawati, Arief Syaichu R., Kuspriyanto

Sekolah Teknik Elektro dan Informatika, Institut Teknologi BandungJalan Ganesha No. 10 Bandung 40132

Email: [email protected], [email protected], [email protected]

ABSTRACT

The practice of plagiarism is not a strange thing anymore, especially among the students

that almost every day working on tasks assigned by the lecturer. The practice of plagiarismis done

by the exchange of source code that have been successful. To over come the practice

of plagiarism, it is not enough just to remind the students that the act of plagiarism isnot well done. Detecting plagiarism practices is a solution that should be done so that

the fraudulent actions can be minimized. Overall, the plagiarism detection software can provide auseful contribution to minimize plagiarism. Using the software can be

a deterrent for students to take a plagiarism. However, the using this software does not provide the

final answer. Software only detect and notify any duplication. Therefore, the intervention ofmanual inspection and assessmentis still needed. The design result obtained by a plagiarism

detection system model for programming assignment in a virtual classroom base on

Moodle and delivery system alerts for the student. The test results show that the

software can detect any similarities in the assignment by generating a percentage of similarity

between the task either comparison between two files or many files. In addition, the software can

deliver alerts from the lecturer for the students that plagiarism is detected using SMS Gateway.

Keywords: plagiarism, plagiarism detection system, virtual classroom, Moodle, SMS Gateway.

I. PENDAHULUAN

Plagiarism is the act of abuse, publication, statement, or claim as your own the thoughts, ideas, writings, or a

creature that actually belongs to someone else[13].

To overcome the practice of plagiarism, it is not enough simply to remind students that the act of plagiarism is

not well done. Plagiarism detection practices is a solution that should be done so that fraudulent activity canbe minimized.

Today has found the software/plagiarism detection tools, including the SIM, SID, MOSS, JPlag, YAP, Plague,Bandit, Cogger, AC and CodeMatch. Use of the software can be a deterrent for students to perform acts of

plagiarism. Software only detect and inform the duplication. Therefore the intervention of manual inspection and

assessment is still needed

II.

PLAGIARISMDETECTION

Plagiarism detection system can be developed for: text data such as essays, articles, journals, research and so

forth; a more structured text documents such as programming languages (source code).

Modifications are usually done by students of programming can be classified as follows[4].

a.

Lexical, changes in the code (source code) program, for example:

1. changing comment (increased or reused, or replaced),2.

changing format,

3. changing variable name.

b. Structural, changing program structure, for example:

1. change the order of the algorithm, does not change program course,

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2. change the procedure becomes a function or vice versa,

3.

the procedure is replaced with the contents of the procedure it self.

The benefits of plagiarism detection system is to aid the detection of the manual in making comparisons between the

amount of source code in a short time.Major aspects of development that must be considered in plagiarism detection system[3]:

a. suitable discriminator to indicate the presence of plagiarism,

b.

make a suitable method for comparing these discriminators,c.

appropriate measurement of similarity.

2.1.

Plagiarism detection method

Two main approaches have been used for plagiarism detection methods of attribute-counting and structure-base[7].

In attribute-counting method, which in comparison is a quantitative measure of some of the metrics program,

while at stucture-based method, which compared the representation of the structure of the program, such as a

linearrepresentation of a string, parse tree, data flow, etc.

(1) Attribute-Countingmethod.A variety of attribute-counting methods that use other metrics continue to emerge, such ascalculation of the

number operator and oprands by Halstead[9]

, cyclomatic complexcity method of McAbe[11]

which measures the flow

of program control by calculating execution path, scope and methods of measurement number. However, attirubte-

counting system only managed to perform effectively for plagiarism detection is done with simplemodifications.

(2)

Stucture-Based MethodIn general, the detection system in structure-based methode is divided in two stages.

1.Tokenization, the parsing code into a collection of tokens called token sequences or profiles. Token isasingle element of the programming language. For example reserved words, punctuation,and operators

[16]. And

the parser is a program that breaks the code into functional components[12]

.

2. Comparing each pair of profile or token sequences. For nprogram that collected the application will do the

n*(n-1)/2 comparisons.

2.2.

Plagiarism Detection Software at the Source

When this has been a lot of plagiarism detection software developed using stucture-basedmethod.1.

Software Similarity Tester(SIM)Software Similarity Tester (SIM) plagiarism detection system was developing in 1999 by Gitchell and Tran[6]as a

system for measuring the similarity between text written in C, Java, Pascal and natural language.

SIM work steps.

Read the program files: read the file and store it in sequence.

Determine the set of interesting runs: the algorithm determines match between two files.

Determine the line numbers of the interesting runs: finds the start and end line number for each chunk.

Print the contents of the runs in order: the stored match and display the analysis in chart.

2. Measure Of Software Similarity(MOSS)Measure of Software Similarity (MOSS) was developed in 1994 by Alex Aiken [2]at Berkeley as a system formeasuring the similarity of source code written in C, C++, Java, or Pascal. MOSS tests the source code in real

file be parse the source code, tokenizing it and apply comparison algorithm (MOSS) to the tokenized form of the

code. And compare it with the source code in other files[15]

.

3.J plagJPLag built and developed by Guido Malpohl from the Department of Informatics University of Karlsruhe[8]. The

system can detect the similarity between source Java, C, C++ and Scheme. Jplag available as a web service

and can be used free of charge.The main characteristic of JPlag can be summarized as follow.

JPlag is available as a web service.

JPlag has a powerful user interface for understanding the results.

JPlag is resource-efficient and scales to large submissions.

JPlag has very good plagiarism detection performance.

4. Shared Information Distance or Software Integrity Detection(SID)SID works in two phases:

In the first phase, source programs are parsed to generate token sequences by standard lexical analyzer.

In the second phase, Token Compress algorithm is used to compute the shared information metric d(x, y)between each program pair within the assignments.


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Figure 2.1 SID Phases[14].

5. CodeMatchCodeMatch[5] compares every file in one directory with every file in another directory, including allsubdirectories if requested. CodeMatch produces a database that can then be exported to an HTML basic reportthat lists the most highly correlated pairs of files. You can click on any particular pair listed in the HTML basic

report see an HTML detailed report that shows the specific items in the files (statements, comments, identifiers,

or instruction sequences) that caused the high correlation.

6.

AntiCopias(AC)AC performs the following steps to compare between students assignments[10].

Distance integration

This stage put the characters in sequence and converting them into sequence of tokens after removing

comments and spaces from the source file.

Token counting similarity distanceThis stage counts the tokens between two assignments using parser (compiler to compare the similarities

between the two sequences) and gives the percentage of similarity.


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Figure 2.2 Parsing Steps[10]

.

2.3.

SMSGateway

SMS Gateway is a unitary device comprising at least a computer with a modem GSM/CDMA, a cardGSM/CDMA, and an application program that serves to organize (receive or send) a message[1]. SMS

Gateway Application capable of integrating the phone with computer technology.

Advantages SMS Gateway is a gateway to the dissemination of information by using sms, it can spread the

message to hundreds of numbers automatically and quickly directly connected to the database with phone numbers

without having to type hundreds of numbersand messages on the phone because all the numbers will be

taken automatically from database. In addition, the SMS Gateway can customize messages to be sent

Picture of the use of SMS Gateway in Moodle can be illustrated as shown below:

Figure 2.3SMS Gateway with Moodle.

III.ANALYSISANDDESIGN

To design a plagiarism detection system is then carried out an analysis of system requirements that will be built.

Requirements of the system requirements are divided into two, namely the functional requirements and non

functional requirements.

3.1 Functional requirements.

Enable teachers to detect plagiarism and cheating in student submitted assignments. The system reads thesubmitted assignments and enters them to the algorithm to find the degree of similarity between them.

Viewing visually aided cheating (similarity) reports. Teachers can display cheating (plagiarism) report, which

contains all submitted assignments and the percentage of similarity of each assignment with others.

The main functions such a registration, login, create courses are already exist in the Moodel (it is not new

functions to be added in this project).

System is capable of displaying file content comparisons that have similarities.

The system can automatically send alerts to students detected cheating or plagiarism action, in the form of smsalerts.

3.2 Non-Functional requirements.

1. Compability. System should be compatible and integrateable with Moodle because it will be added as new

feature to Moodle.2.

Easy to use. Teachers will interact with the system to generate plagiarism report through a user-friendly graphical

user interface. Furthermore, the generated reports will contain both textual and visual (bars, charts, etc.)

representation for the results.

3.3

Development requirements

1. Hardware resources.

- PersonalComputer(PC), for server application.- LAN or WAN, used to connect a computer server with client computer.- Modem for SMS Gateway connection.

2. Software resources.

Plagiarism detection system to integrate into the Moodle virtual classroom platform, it would require some

software to suit the needs of Moodle. Moodle is a Web-based applications using PHP programming language, and

database applications using MySQL,so it is a system built using the PHP programming and MySQL database. As for


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the SMS Gateway can be integrated into Moodle, used Ozeki NG, because the Ozeki NG SMS Gateway is

a software that can be integrated into Moodle.

3.4

System design

The system designed involving three components lecturer, students and administrators. Students can access

a particular course, submit assignments, and receive alerts. Lecturers provide course material, assign tasks, view theresults of plagiarism detection, see the same results file detection, and provide alerts, while administrators manage

user data and manage the system. Scenarios for each user is indicated by the flowchart below.

1. Scenario for the lecturer.

2.

Scenario for the students.


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3.

Systems scenario

In plagiarism detection systems programming tasks in the Moodle-based virtual classroom, the system first checks

the username and password entered by the lecturer or students into a database match, when appropriate, the

system displays the pages of virtual classes and courses that exist. The system will display the questions that have

been uploaded by the lecturer and put the task on submit students into the database. The system detected a

similarity between the tasks. Detection procedures are as follows.1. Distance integration.


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This stage put the characters in sequence and converting them into sequence of tokens after removing comments

and spaces from the source file.2.

Token counting similarity distance.

This stage counts the tokens between two assignments using parser (compiler to compare the similarities between

the two sequences) and gives the percentage of similarity.

3.

Visualize the detection results in table form percentage comparisons, both comparisonsbetween the two files as

well as comparisons between multiple files.In the process of the system will display a page alerts SMS Gateway for lecturers. The system will deliver alerts that

provided teachers to students in the form of an SMS.

IV.

ANALISYSOFTHERESULTS

This section will be delivered the results of testing the software presented in the form of tables. The

test performed is the scenario adopted for testing the software in accordance with the function use case that has

been developed.

Table 4.1 Prior to testing aspect plagiarism detection process.

Aspects of the tested Aspect before the plagiarism detection process

Process Plagiarisme detection process

Use case Login, give the task, displaying the task, the task of collecting

Testing details Expected Results of softwaretesting

Analysis of test results

Perform the login process by

entering the login function, thecorrect username and password

Login process is

successful, all active in thesystem menu

conform In order for these processes

can be successful it mustbe in accordance with theconfiguration that has beendone before.

Conducting the process ofgiving the task to activate buttonand insert about the taskassignment

Assignment page appears, typeof assignment, aboutthe column, limit time spent on

conform

Process by activating the button

displays the task assignment

Show a page that contains about

task assignment andexecution time limit

conform

Make the processof collecting tasks by activatingbutton assignment

Shown assignment page, thecolumn to submit answers to thetask, and tabs for editing tasks

conform

Table 4.2 Testing Aspects of Plagiarism Detection Process

Aspects of the tested Aspect the plagiarism detection process


Use case Reading files, detect plagiarism, plagiarism detection result display

Testing details Expected Results ofsoftware testing


Make the process of reading a

file answers students who havebeen placed in one directory

Comparing the files tasks

collected by the student

Conform The process plagiarism

detection of student tasksperformed by the system bymaking the task file into theform of tokens and parse,

then calculate the similarityresulting in a percentage levelof similarity.

Conducting the process ofcounting the percentage ofsimilarity between the studentassignment

Calculate the percentage ofsimilarity among the studentstasks

Conform

Showing results of plagiarismdetection in student task

Plagiarism detection resultsof shown in table form the

similarity percentage

Conform


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Tabel 4.3. Aspects of Testing Process After the detection of plagiarism

Aspects of the tested Aspect the plagiarism detection process


Use case Provides alerts, receive alerts, create exam questions, exam answers to upload,view exam answers, provide value, display value

Testing details Expected Results of softwaretesting


Conducting the process ofproviding alerts to students, witha percentage similarity above50% by using sms gateway

Students with a level ofsimilaritypercentage above50% receive a smsalerts

Conform The process of grantingalerts by lecturer of studentswith task similaritypercentage level above 50%

by using sms gateway.

V.

CONCLUSIONS

The conclusion of the design and implementation of plagiarism detection system on the programming task in a

virtual classroom with Moodle is that software plagiarism detection systems that are designed and tested, can make

or process any of the following.

Plagiarism detection systems programming tasks in a virtual classroom with Moodle allows the lecturer to know

the existence of similarities among students that if the task is done manually requires considerable

effort, especially when the number of students attending is quite a lot.

Plagiarism detection systems programming tasks in a virtual classroom with Moodle is able to show the

percentage of similarty in student assignment, whether the similarity between the two files as well as similarities

between one file into many files.

In addition to show the percentage of similarity detection results, the system was able to show details of thecontents of the detected files have similarities.

System of alerts that are designed in this thesis, to address its students with a more efficient in terms of time, so

that students can receive alerts/information as soon as the detection process is completed.Constraints faced in making the application of plagiarism detection system on the programming task in a virtual

classroom with Moodle is on the submission of detail edresemblance of the detected content file, because the

submission of this information must go through the file attachment facility can not be done on medium SMS.

REFERENCES

[1]

________, OzekiNG SMS Gateway, http://www1.sms-integration.com.

[2]

Aiken, Alex, MOSS (Measure Of Software Similarity) plagiarism detection system, University ofBerkeley, 1994, http://www.cs.berkeley.edu/~moss/.

[3] Clough, P.D., Old and New Challenges in automatic PlagiarismDetection, Departement of ComputerScience, University of Sheffield, UK, 2003.

[4] Clough, P.D., Plagiarismin Natural and Programming Languages: An Overview of Current Tools andTechnologies, Departement of Computer Science, University of Sheffield, UK, July 2000.

[5] CodeMatch, http://www.zeidmanconsulting.com/CodeSuite.htm.

[6] Dick Grune and Matty Huntjens, Het detecteren van kopien bij informatica-practica (in Dutch),Informatie 13, pp(864-867), 11 November 1989.

[7]

Kristina L. Verco and Michael J. Wise, Software for Detecting Suspected Plagiarism: ComparingStructure and Attribute-Counting Systems, 1stAustralian Conference on Computer Science Education,Sydney, Australia, July 3-5, 1996.

[8]

Lutz Prechelt, Guido Malpohl and Michael Philippsen, JPlag: Finding Plagiarisms among a Set ofPrograms, 2000, http://page.mi.fu-berlin.de/prechelt/Biblio/jplagTR.pdf.

[9]

M. H. Halstead, Elements of software science,North Holland, New York, 1977.[10] Manuel Freire, Manuel Cebrifn and Emilio del Rosal Escuela, AC: An Integrated Source Code Plagiarism

Detection Environment, Polit_ecnica Superior, Universidad Aut_onoma de Madrid, 2007.[11] McCabe, T.J., A complexity measure, IEEE Transactions on Software Engineering, SE-2 (4), pp(308-

320), December, 1976.

[12] Miller, George A., A lexical database for the english langu

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