2011 KRRI Technical Papers Abstracts Electromagnetic Induction and Metallic Foil Loops ... using Permanent Magnet ... Urban Transit Standardization Project

2011 KRRI Technical Papers

Abstracts

2012. 1

Chapter 1. Bogies and Vehicles ······························· 11-01 Measurement of the Disc-Pad Friction Coefficient

for Mechanical Brakes Using Direct and Indirect Methods

1-02 Experimental Investigation of Composite Sandwich Square Tubes under Quasi-Static and Dynamic Axial Crushing

1-03 A Study on Crushing Behaviors of Composite Circular Tubes with Different Reinforcing Fibers

1-04 Experimental and Numerical Investigations of Mode I Delamination Behaviors of Woven Fabric Composites with Carbon, Kevlar and Their Hybrid Fibers

1-05 Evaluation of the Material Properties of an OFHC Copper Film at High Strain Rates Using a Micro-Testing Machine

1-06 Effect of Punch Angle on Energy Absorbing Characteristics of Tube-Type Crash Element

1-07 Parametric Study of Lateral Stability for a Railway Vehicle

1-08 Numerical Stress Analysis and Rolling Contact Fatigue of White Etching Layer on Rail Steel

1-09 Longitudinal Strain Monitoring of Rail Using a Distributed Fiber Sensor Based on Brillouin Optical Correlation Domain Analysis

1-10 Simultaneous Two-Axis Vibration Measurement of a Nonmetallic Cylinder by Electromagnetic Induction and Metallic Foil Loops

1-11 3D Finite Element Analysis of Friction Stir Welding of Al6061 Plates

1-12 Failure Mode Analysis and Friction Material Development of the KTX Tread Brake

1-13 Evaluation of Residual Stress for Thermal Damage of Railway Wheel Tread

1-14 Effect of Punch Shapes on Failure Instability of Expansion Tube

1-15 Vibration Analysis of Tread Brake Block in the Brake Dynamometer for the High Speed Train

1-16 Dynamometer Tests of Brake Shoes under Wet Conditions for the High Speed Trains

CONTENTS

1-17 Remote Sensing of the Lateral Force for the Scaled Active Steering Railway Vehicle

1-18 Expanded Uncertainty in Measurements of Vertical and Lateral Behaviors for the Rubber-Tired Light Rail Vehicle

1-19 Strength Analysis of Chassis Structure for Medium-Sized Low-Floor Vehicle under Dynamic Load Cases

1-20 A Feasibility Study on the Energy Harvesting Technology for the Real Time Monitoring System of the Railroad Vehicle

1-21 A Study on the Wireless Onboard Monitoring System for Railroad Vehicle Axle Bearings Using the SAW Sensor

1-22 Integrity Evaluation of Railway Bogie Using Infrared Thermography Technique

1-23 Analysis of Fracture Behavior in Polymer Matrix Composites by Infrared Thermography

1-24 End-Shape Effect for Stress Concentration Reduction of Composite Single-Lap Bonded Joint

1-25 Stress Reduction Methods of GFRP/Mg Single Lap Bonded Joints : Finite Element Analysis

1-26 Setting the Service Reliability Target for Meeting the Punctuality Requirement of the Railroad System

1-27 A Study on Evaluating System Performance for Light-Weight Rolling Stock

1-28 Designing a Microphone Array System for Noise Measurements on High-Speed Trains

1-29 Effects of Surface Defects on Rolling Contact Fatigue of Rail

1-30 Hierarchical Views for Distributed Databases of Semantically Condensed Data through Web Links to Sensor Data

1-31 A Web Data Exchange System for Cooperative Work in CAE

1-32 An Abbreviate Representation for Semantically Indexing of Physically Massive Data Out of Sensor Networks on the Rove

1-33 A Study on the Fracture Test in Running System of Railway

1-34 Strain Monitoring of Composite Steel Girder Bridge Using Distributed Optical Fibre Sensor System

1-35 Three-Dimensional Steady-State Rolling Contact Analysis Using Finite Element Method

1-36 Three-Dimensional Transient Rolling Contact Analysis of Similar Elastic Cylinders

1-37 Influence of the Speeds on the Curve Squeal Noise of Railway Vehicles

1-38 Prediction of Surface Crack Growth Considering the Wheel Load Increment Due to Rail Defect

1-39 The Study on the Locomotive Cab Design Considering Driver's Physical Characteristics in Korea

1-40 Weight Reducing of Aluminum Extrusion Profiles of a Railway Carbody Based on Optimization Method

1-41 Review of Non-Destructive Evaluation Technologies for Rail Inspection

1-42 Evaluation of Running Safety for Depressed Center Flat Car of 3-axle Bogie

1-43 Analysis on the Running Stability of Rolling-Stock according to Wheel Profile Wear

Chapter 2. Railroad Infrastructures ····················· 442-01 Experimental Evaluations of Track Structure Effects

on Dynamic Properties of Railway Bridges

2-02 Experimental and Numerical Analyses of an Opening in a Jointed Rock Mass under Biaxial Compression

2-03 Optimization of Alignment Considering Ride Comfort for Superimposition of Vertical and Horizontal Curves

2-04 Lateral Overturning Failures of Old Concrete Gravity Pier on Sandy Soils

2-05 Effect of Crack Width on Chloride Diffusion Coefficients of Concrete by Steady-State Migration Tests

2-06 Experimental and Numerical Investigation on Dynamic Amplification Factors of an Urban Maglev Guideway

2-07 Tilting Train-Induced Roadbed Response on the Conventional Line

2-08 Traffic Safety & Passenger Comforts of a Suspension Bridge Considering Seismic Loads

2-09 Centrifuge-Shaking Table Test for Seismic Performance Evaluation of Subway Station

2-10 Investigation of the Maintenance Criteria for the Rail Surface Defects in High-Speed Railways

2-11 Determination of Upper Limit of Rail Pad Stiffness for Ballasted and Concrete Track of High-Speed Railway Considering Running Safety

2-12 Evaluation of Train Running Safety During Construction of Temporary Bridge on Existing Railway

2-13 An Experiment and Analysis of Precast Concrete Baseplate on Bimodal Tram Dedicated Bridge

2-14 A Study on the Basic and Compression Characteristics of Lightweight Waste for Use as Fill Materials

2-15 An Experimental Study on Local Stability of Eco-Block

2-16 Development of FBG Accelerometer for Railway Tunnel Vibration

2-17 Evaluation of Dynamic Stability for Structural Bar Reinforced Precast and Prestressed Retaining Wall for Moving Train Load

2-18 Dynamic Response Characteristics for Two-Layered Trackbed Structure by Train Load

2-19 Reduction of Shear Strength of Railway Roadbed Materials with Freezing-Thawing Cycle

2-20 A Comparative of Ground Stress with Difference of The Fixed Point Loading and Moving Wheel Loading

2-21 Evaluation of Correlation between Strain Mudulus (Ev2) and Deformation Modulus (ELFWD) Using Cyclic Plate Loading Test and LFWD

Chapter 3. Electric & Signal System ················· 653-01 Conceptual Design for HTS Coil in

Superconducting Electromagnet for Maglev

3-02 Characteristics of Persistent-Current Mode of HTS Coil on Superconducting Electromagnet

3-03 Improvement of Thrust Force Properties of Linear Synchronous Motor for an Ultra-High-Speed Tube Train

3-04 Parameter Design of IPMSM With Concentrated Winding Considering Partial Magnetic Saturation

3-05 Thrust Performance Improvement of a Linear Induction Motor

3-06 Magnetic Interference on the Infrastructure for a Super-Speed Tube Train

3-07 License Plate Extraction Method for Identification of Vehicle Violations at a Railway Level Crossing

3-08 Implementation of a Condition Monitoring System for Mold Transformers in DC Substations

3-09 Development of an Arc Detector Assessment System by Loss of Contact Between Pantograph and Contact Wire in Electric Railway

3-10 Analysis of Iron-filings Trapping Characteristics on Concrete Slab Track using Permanent Magnet

3-11 A Study on an Airgap Control System in a Rotary-small-scaled Linear Induction Motor for Railway

3-12 Development of a Series Hybrid Propulsion System for Bimodal Tram

3-13 Harmonic Frequency Analysis of Interlocking System for Rolling Stock Operation in Electrical Railroads

3-14 Analysis of Return Current for Rolling Stock Operation on Electrical Railroads

3-15 Analysis of Interoperability Test between a Different Kind of Train Control System

3-16 Vehicle Running Characteristic Simulator Using Induction Motor

3-17 Evaluations of the Robustness of Guidance Controller for a Bimodal Tram

3-18 The Design and Analysis of Recognition Structure for Absolute Train Positioning System of High-speed Maglev Train System

3-19 A Study on the Reliability/Safety Assessment and Improvement of USN Gateway for Train Control

3-20 Performance Evaluation of Wireless Sensor Networks in the Subway Station of Workroom

3-21 Development of a Simulator for Radio Propagation Path Loss in Tunnel at 18GHz

3-22 Intelligent Video Surveillance System using RFID Technology

3-23 A Study on a Configuration of the Load Characteristic Evaluation Device Using Hydraulic Power for the Analysis of the Tilting Kinetic Mechanism

3-24 Development of the Operation Simulator for the PRT System

3-25 A Study on Establishment of Signaling Systems to Speed up Conventional Railway

3-26 Development of Door Control Unit for the Electric Plug-in Door of Subway Train

3-27 An Analysis on Rise of Rail Potential and A Study on Control Method for It in DC Feeding System

3-28 A Study on the Real Time Measuring Technique of Stray Current by Using Return Current Ratio In the DC Railway System

3-29 A Study on Fault Location Estimation Technique Using the distribution Ratio of Catenary Current in AC Feeding System

3-30 Bidirectional Alarm Equipment for Protection for Trackside Worker using Bone-anchored Speaker

Chapter 4. Environmental Engineering ··············· 954-01 Novel Air Filtration Device for Building Air

Handling Unit

4-02 Instability Analysis in Curve Noise of Urban Railway Systems for Optimal Steering Bogie Development

4-03 Experimental Study on Particle Collection Efficiency of Axial-Flow Cyclone in Air Handling Unit

4-04 Investigation of Airborne Microorganism in Cabin of the KTX

4-05 Development of Air Cleaning Roll-Filter for Improving IAQ in Subway

4-06 Air Quality in the Subway Cabins of the Seoul Metropolitan Area and Analysis of Its Influencing Factors Using Multivariate Statistics

4-07 A Study for Characteristics of PM10 in the Subway passenger cabins

4-08 A Study on the Combustion Characteristics and Greenhouse Gas Emissions from Rice Husks with Varied Heat Fluxes

4-09 Full-Scale Test of Smoke-Control Performance of a Subway Tunnel

4-10 The Evaluation of GHG Emissions in Railroad Construction Sector

4-11 A Research on the Greenhouse Gas Emission Reduction of Railway Structure Construction Stage

4-12 Analysis of Vortex Shedding Phenomena around Pantograph Panhead for Train Using Large Eddy Simulation

4-13 The Distribution Characteristics of Carbon Dioxide in Indoor School Spaces

4-14 Adsorption and Desorption Characteristics of Carbon Dioxide at Low Concentration on Zeolite 5A and 13X

4-15 Study on the Removal of Carbon Dioxide in the Subway Cabin Using Zeolite Type Carbon Dioxide Adsorbent

4-16 A Study on the Performance Test and Acoustic Design of Interference Type Noise Reduction Device for Railway Noise

Chapter 5. Others ···················································· 1115-01 A Multi-Class Closed Queueing Maintenance

Network Model with a Parts Inventory System

5-02 A Study on Setting Up National Railway Safety Target

5-03 A Study on Revising Train Departure Time for Reducing Electric Power Consumption

5-04 Track Assignment and Load Planning Problems in Railway Container Terminals

5-05 Metaheuristics of the Rail Crane Scheduling Problem

5-06 Analysis of PRT Station Capacity Based on Micro Simulation

5-07 Analysis on Recognition and Current Use of Pallets for Through Transit

5-08 Analysis of Operational Issues for ICT-based On-Board Train Control System

5-09 A Study on the Train Composition Requirements for Safety Operation of Urban-Transit

5-10 A Study on the DB Establishment and Traceable Management of the Urban Transit Standardization Project

- 1 -

Young-Guk Kim It is necessary to guarantee the proper brake force to stop a train safely in a limited distance and o adjust its speed. Currently, most trains are run by electrical power and have a combined electrical and mechanical (friction) braking system. The mechanical brake force is determined by many parameters, such as the friction coefficient of the brake disc and pad, the pressure in the brake cylinder, the brake cylinder’'s cross sectional area and the brake linkage ratio. In general, the friction coefficient data of the brake disc and pad have been taken through a dynamo-test in a laboratory, but these data might not be well matched with real data under operating conditions because of the difference in data acquisition conditions. The present study examined two methodologies that can measure the friction coefficient of the brake pad and disc based on a train’'s real operating conditions. The first method was the direct method, which measured the brake force and clamping force applied on the mechanical brake by using strain gauges installed on the brake to calculate the friction coefficient. The second was an indirect method that obtained the friction coefficient by using the weight of the train and the equivalent brake force. Those variables were calculated from the longitudinal dynamic characteristics, such as resistance to motion, gradient resistance and curved resistance. These two methodologies were used to obtain the disc-pad friction coefficient for the mechanical brakes of a Korean high-speed train (HSR350x).

[email protected]

82-31-460-5612

SCIE

International Journal of Automotive Technology

Vol. 21 No. 1

2011. 2

Measurement of the Disc-Pad Friction Coefficient for Mechanical Brakes Using Direct and Indirect Methods

1-01

Abstract

Journal Info.

First Author

- 2 -

Jung-Seok Kim In this study, the crush behaviors of square sandwich

composite tubes with woven fabric carbon/epoxy skins and

aluminum honeycomb cores with the different honeycomb

cell sizes and tube sizes were evaluated. For the

evaluation, four different kinds of tubes were fabricated

and crushed under quasi-static and dynamic impact loads.

The impact tests were carried out using heavy wagons.

From the test results, the crushing mode under the

dynamic load was changed into more stable collapse than

the corresponding static tests. Additionally, the increased

bond strength between the honeycomb core and the

composite face leaded to a higher energy absorption

capability.

[email protected]

82-31-460-5663

SCIE

Advanced Composite Materials

Vol. 20 No. 4

2011. 8

First Author Abstract

Journal Info.

1-02 Experimental Investigation of Composite Sandwich Square Tubes under Quasi-Static and Dynamic Axial Crushing

- 3 -

Jung-Seok Kim In this study, the failure modes and energy

absorption capabilities of different kinds of circular

tubes made of carbon, Kevlar, and carboneKevlar

hybrid fibers composites with epoxy resin have been

evaluated. The relationship between the crushing

parameters (specific energy absorption, maximum

peak load, mean crushing load) and the material

properties for different fibers and patternswas also

investigated. The fabric carbon/epoxy tubes had the

best energy absorption capability (specific energy

absorption of 81.7%). In contrast, the tubes made of

Kevlar showed the worst energy absorption

capability. Based on the linear regression analysis

results, the crushing parameters generally showed

good correlation with the compressive strength and

shear modulus. In particular, the specific energy

absorption of the tubes with the brittle fracture mode

revealed the strongest correlation with the

compressive strength (R-square value ¼ 0.90).

[email protected]

82-31-460-5663

SCI

International Journal of Impact Engineering

Vol. 38 No. 4

2011. 4


Journal Info.

1-03A Study on Crushing Behaviors of Composite Circular Tubes with Different Reinforcing Fibers

- 4 -

Jung-Seok Kim This paper studied the effect of the hybridization of

carbon and Kevlar fibers on mode I interlaminar

fracture toughness and crack propagation behaviors

with double cantilever beam (DCB) tests. The crack

propagation characteristics, crack growth trend and

rate, and fracture surfaces were observed using an

optical microscope and SEM micrographs for the

three different types of materials. Moreover, details

of the stress distribution around the crack tip and

the crack propagation pattern across the width of the

DCB specimen were investigated using the finite

element method, including a cohesive element. The

mode I interlaminar fracture toughness of Carbon-Kevlar

hybrid/epoxy was nearly average for carbon/epoxy

and Kevlar/epoxy. The maximum load predicted by

the numerical method showed good agreement within

an error of 5% with the experimental results.

[email protected]

82-31-460-5663

SCIE

International Journal of Precision Engineering and Manufacturing

Vol. 12 No. 2

2011. 4

1-04 Experimental and Numerical Investigations of Mode I Delamination Behaviors of Woven Fabric Composites with Carbon, Kevlar and Their Hybrid Fibers

Corresponding Author Abstract

Journal Info.

- 5 -

Jin-Sung Kim The material properties of an oxygen-free high thermal conductivity (OFHC) film with a thickness of 0.1 mm were evaluated at strain rates ranging from 10−-3/s to 103/s using a high-speed material micro-testing machine (HSMMTM). The high strain-rate material properties of thin films are important especially for an evaluation of the structural reliability of micro-formed parts and MEMS products. The high strain-rate material testing methods of thin films, however, have yet to be established to the point that the testing methods of larger specimens for electronics, auto-body, train, ship, and ocean structures are. For evaluation, a new type of HSMMTM was developed to conduct high-speed tensile tests of thin films. This machine is capable of testing at a sufficiently high tensile speed with an electromagnetic actuator, a novel gripping mechanism, and an accurate load measurement system. The OFHC copper film shows high strain-rate sensitivity in terms of the flow stress, fracture elongation, and strain hardening. These measures increase as the tensile strain rate increases. The rate-dependent material properties of an OFHC copper film are also compared with those of a bulk OFHC copper sheet with a thickness of 1 mm. The flow stress of an OFHC copper film is relatively low compared to that of a bulk OFHC copper sheet in the entire range of strain rates,

[email protected]

82-31-460-5266

SCI

Experimental Mechanics

Vol. 51 No. 6

2011. 6


Journal Info.

1-05 Evaluation of the Material Properties of an OFHC Copper Film at High Strain Rates Using a Micro-Testing Machine

- 6 -

Tae-Soo Kwon As a crash energy absorber, a tube-type crash element(expansion tube) dissipates kinetic energy through the internal deformation energy of the tube and frictional energy. In this paper, the effects of the variation of punch angles on the energy absorbing characteristics of expansion tubes were studied by quasi-static tests with three punch angles (15°, 30°, 45°). A finite element analysis of the tube expanding process applying a shear friction model (m=τmax/K) was carried out to confirm the variation of the shear friction factor with respect to punch angles using the inverse method. In addition, additional analysis were performed with angles of 20°, 25°, 35°, and 40° to study the effect of the punch angles on the internal deformation energy, frictional energy, and expansion ratio of the tubes. The results of the experiment and finite element analysis showed that the shear friction factor was inversely proportional to the punch angles and a specific punch angle existed at which the absorbed energy and expansion ratio did not increase any further.

[email protected]

82-31-460-5263

SCIE


Vol. 12 No. 3

2011. 6


Journal Info.

1-06Effect of Punch Angle on Energy Absorbing Characteristics of Tube-Type Crash Element

- 7 -

Joon-Hyuk Park This paper deals with the lateral stability for a

railway vehicle. Particularly, nonlinear critical speed

is investigated via bifurcation analysis. Shooting

method and trust region algorithm are applied to

calculate the limit cycle of the nonlinear dynamic

vehicle model. In case of the investigated vehicle

model, the influences of the suspension parameters

on the critical speeds are not large. The effects of

friction coefficient are also small. However, there is

an overall consistency that the nonlinear critical

speed is decreased when the stiffness of the suspension

is reduced. Study of the excitation conditions where

the stable limit cycles occur gives very useful

information to understand the nonlinear dynamic

behavior of a railway vehicle and to test the vehicle

with roller rig test stands. According to the results,

the direction of the excitation is very important as

well as the amplitude and frequency to acquire

accurate nonlinear critical speed.

[email protected]

82-31-460-5276

SCIE

Journal of Mechanical Science and Technology

Vol. 25 No. 7

2011. 7


Journal Info.

1-07Parametric Study of Lateral Stability for a Railway Vehicle

- 8 -

Jung-Won Seo White Etching Layer is a phenomenon that occurs

on the surface of rails due to wheel/rail interactions

such as excessive braking and acceleration. We have

investigated rolling contact fatigue damage and the

behavior of WEL using the twin disc test and Finite

Element analysis. WEL was simulated by wheel flat

tests. Two types of cracks were observed to occur

within WEL specimens after the rolling contact test.

The shortest fatigue life from Finite Element and

fatigue analysis was evaluated using the starting

point of WEL, and the results were consistent with

those from contact fatigue tests.

[email protected]

82-31-460-5210

SCI

International Journal of Fatigue

Vol. 33 No. 2

2011. 2


Journal Info.

1-08Numerical Stress Analysis and Rolling Contact Fatigue of White Etching Layer on Rail Steel

- 9 -

Hyuk-Jin Yoon A fiber-optic distributed sensor system is configured to measure the longitudinal strain distribution of a rail in real time. The system is based on the Brillouin correlation domain analysis (BOCDA), in which the variation of local Brillouin frequency (νB) is measured that linearly depends on the strain applied to the optical fiber. In the test measurement, the longitudinal strain distribution along a 2.8 m rail is measured under different loading conditions with a spatial resolution of 3.8 cm and an accuracy of ±15 με.

[email protected]

82-31-460-5565

SCI

NDT&E International

Vol. 33 No. 2

2011. 2


Journal Info.

1-09 Longitudinal Strain Monitoring of Rail Using a Distributed Fiber Sensor Based on Brillouin Optical Correlation Domain Analysis

- 10 -

Soon-Woo Han This work presents a method based on electromagnetic induction for the simultaneous non-contact measurement of two-axis lateral vibrations of a nonmetallic cylinder. The suggested method employs two pairs of hollow metallic loops, four pairs of permanent magnets and two solenoids. When the cylinder vibrates, eddy currents are generated in the metallic loops due to electromagnetic induction. The current in one pair of loop is induced by the lateral vibration in one direction, while the other by the lateral vibration in the perpendicular direction. The induced currents can be sensed through the remotely installed solenoids. While the proposed technique can be useful for the vibration measurement in hot or insulated cylinders, for which a contact type sensor is hardly applicable, the present study is focused on its underlying measurement mechanism and fundamental experiments. To this end, two-axis vibrations and frequency response functions of a thin nonmetallic cylinder were measured simultaneously by the proposed sensor. They were compared with those extracted by using commercial accelerometers to check the working performance of the proposed measurement technique. The effects of some parameters in the proposed technique, such as the length of the loop, were also investigated.

[email protected]

82-31-460-5537

SCIE

Journal of Mechanical Science and Technology

Vol. 25 No. 8

2011. 8


Journal Info.

1-10 Simultaneous Two-Axis Vibration Measurement of a Nonmetallic Cylinder by Electromagnetic Induction and Metallic Foil Loops

- 11 -

Byeong-Choon Goo Friction stir welding (FSW) is a solid state joining

method patented in 1991 by The Welding Institute

(TWI). It is widely used for joining light metals

such as Al and Mg alloys. Foreign railway vehicle

manufacturing companies have been applying FSW to

car body welding, but domestic companies are in the

beginning of feasibility study. Therefore, lots of

experimental and analytical study is needed. In this

study, three-dimensional finite element modeling of

the friction stir welding of two Al6061-T6 plates

was carried out. And temperature field and residual

stresses were obtained and compared to experimental

results in the literature. It is found the analytic

thermal field is in a good agreement with the

experimental results, but there are some differences

between numerical and experimental residual stresses.

[email protected]

82-31-460-5243

Journal of KWJS

Vol. 29 No. 4

2011. 8


Journal Info.

1-113D Finite Element Analysis of Friction Stir Welding

of Al6061 Plates

- 12 -

Byeong-Choon Goo The shoe brake of the KTX is used in low speed

when the electric brake is not effective. The main

purpose of the shoe brake is to stop the train to a

desired stop point at the station. Lots of defects

have been encountered in the shoe brake unit since

the KTX started its operation. To improve the

reliability of shoe brake unit of the KTX power car,

first of all, failure modes of the KTX shoe brake

unit were analyzed. Main failure modes are cracks in

the shoe friction material and fracture in the welded

joints of the shoe backing steel structure. Several

methods to remove the defects of the shoe brake

unit were proposed and on-board tests were carried

out: Increase of the strength of the shoe key and

shoe cam, which decreased a little the occurrence of

cracks in the shoe friction material; Redesign of the

shoe backing steel structure, which eliminated the

occurrence of the cracks in the backing plate but

could not solve completely the crack problem in the

shoe friction material; Development of a new friction

material, which with redesign of the shoe backing

steel structure could solve satisfactorily the crack

problem in the shoe friction material.

[email protected]

82-31-460-5243

Journal of the Korean Society for Railway

Vol. 14 No. 2

2011. 4


Journal Info.

1-12Failure Mode Analysis and Friction Material

Development of the KTX Tread Brake

- 13 -

Seok-Jin Kwon The thermo-mechanical interaction between brake

block and wheel tread during braking has been

found to cause thermal crack on the wheel tread.

Due to thermal expansion of the rim material, the

thermal cracks will protrude from the wheel tread

and be more exposed to wear during the wheel/block

contact than the rest of the tread surface. The wheel

rim is in residual compression stress when is new.

After service running, the region in the tread has

reversed to tension. This condition can lead to the

formation and growth of thermal cracks in the rim

which can ultimately lead to premature failure of

wheel. In the present paper, the thermal cracks of

railway wheel, one of severe damages on the wheel

tread, were evaluated to understand the safety of

railway wheel in running condition. The residual

stresses for damaged wheel which are applied to

tread brake are investigated. Mainly X-ray diffusion

method is used. Under the condition of concurrent

loading of continuous rolling contact with rails and

cyclic frictional heat from brake blocks, the

reduction of residual stress is found to correlate well

with the thermal crack initiation.

[email protected]

82-31-460-5249

Journal of the Korean Society for Precision Engineering

Vol. 28 No. 5

2011. 5


Journal Info.

1-13Evaluation of Residual Stress for Thermal Damage

of Railway Wheel Tread

- 14 -

Tae-Su Kwon The rupture of an expansion tube is mainly affected

by the expansion ratio and the external shape of the

punch used to expand the tube. In order to prevent

the tube from rupture, the effect of the external

shape of the punch should be considered in the

design. The aim of this paper is to confirm the

effect of key design parameters of the punch on

rupture of the tube using a finite element analysis

with a ductile damage model. The results of the

analysis indicated that the expansion ratio of the

tube was mainly affected by variation of the radius

of the punch. However, the rupture was more

affected by variation of the punch angle than the

radius of the punch. The existence of a specific

punch angle at which rupture did not occur, even if

the radius of the punch was increased, was found

from the results.

[email protected]

82-31-460-5263

Transactions of KSAE

Vol. 19 No. 2

2011. 2


Journal Info.

1-14Effect of Punch Shapes on Failure Instability of

Expansion Tube

- 15 -

Min-Soo Kim This paper deals with the frequency analysis of the

abnormal vibration in the specific speed range when

the tread brake test is applied in the brake

dynamometer. Generally brake system of railway

vehicles has a crucial role for the safety as well as

riding quality of passengers. And dynamometer tests

are widely used to evaluate the friction and wear

performance of railroad friction composition brake

shoes including the emergence brake, continuous brake,

and so on. Experiments on the brake dynamometer

for the high speed train are provided to illustrate the

frequency analysis of the abnormal vibration in

vehicle speed at 140 [km/h] and 70 [km/h] under

the 920 [mm] wheel diameter using the 3-axis

accelerometers.

[email protected]

82-31-460-5205

International Journal of Systems Applications Engineering & Development

Vol. 5 No. 1

2011. 2


Journal Info.

1-15Vibration Analysis of Tread Brake Block in the

Brake Dynamometer for the High Speed Train

- 16 -

Min-Soo Kim This paper discuss comparative studies of the wheel

tread brake with composite brake blocks between

under conditions with dry and wet using the

dynamometer tests for the high speed trains. Generally

brake system of railway vehicles has a crucial role

for the safety as well as riding quality of

passengers. And brake dynamometers are widely used

to evaluate the performance of brake systems and

test the brake parts under various environments

(weight, velocity, brake force, wet-dry conditions).

Especially, in the process of the brake stops, the

friction coefficients between under dry and wet conditions

must not deviate from each other by more than 15%

under the same testing conditions. Experiments on

the brake dynamometer for the high speed trains are

shown to illustrate the comparative studies of the

tread brake of dynamometer tests between under dry

and wet conditions with initial vehicle speed at 200

[km/h] and 80 [km/h] considering the 920 [mm]

wheel diameter, espectively.

[email protected]

82-31-460-5205


Vol. 5 No. 2

2011. 4


Journal Info.

1-16Dynamometer Tests of Brake Shoes under Wet

Conditions for the High Speed Trains

- 17 -

Min-Soo Kim This paper describes the performance measurement

system of the active steering railway vehicle with

the scaled test bed using the acquisition telemetry

system about the wheel lateral force. Active steering

system of railway vehicles has proven its ability to

bridge the gap between stability and curve

friendliness. This scaled test-bed system consists of

two steering actuators, a steering controller, and

various sensor systems to detect lateral displacement,

vibration, track curvature, and sensor systems. To

compare with the various control strategies, we

installed the telemetry systems on the steering

wheelsets to detect the wheel/rail lateral force.

Running test results of 1/5 scaled active steering

vehicle on the curved track show that the proposed

measuring system has good performance.

[email protected]

82-31-460-5205


Vol. 5 No. 1

2011. 2


Journal Info.

1-17Remote Sensing of the Lateral Force for the

Scaled Active Steering Railway Vehicle

- 18 -

Yeon-Su Kim In the public transport vehicle, vertical and lateral

behaviors have a significant effect on ride comfort

and safety of passengers on curved track. Based on

vertical and lateral vibration accelerations measured

on floor level in passenger compartment when the

K-AGT ran on the minimum curvature of the

2.4km-test track in driverless mode, expanded

uncertainties in measurement were estimated

statistically. In addition, vertical and lateral dynamic

behaviors of the K-AGT were discussed in this

paper.

[email protected]

82-31-460-5730

Key Engineering Materials

Vols. 452-453

2011. 1


Journal Info.

1-18Expanded Uncertainty in Measurements of Vertical and Lateral Behaviors for the Rubber-Tired Light Rail Vehicle

- 19 -

Yeon-Su Kim For the medium-sized low-floor bus, backbone

structure of chassis was designed to have light-weight

structure with SAPH (Steel Automobile Press Hot

rolled) 440. Strength for the designed backbone

structure was also analyzed by finite element method

under various dynamic load cases considered in this

paper. On the basis of the analysis results, the

structural safety for the designed backbone structure

was evaluated and discussed in this paper.

[email protected]

82-31-460-5730


Vols. 452-453

2011. 1


Journal Info.

1-19Strength Analysis of Chassis Structure for Medium-Sized Low-Floor Vehicle under Dynamic Load Cases

- 20 -

Jae-Hoon Kim This study was intended to identify the applicability

of energy harvesting technologies which is regarded

the new and renewable energy for real time/wireless

monitoring the intelligent railroad system. The

surrounding energy generated under the normal

operation environment was monitored using high

speed railroad vehicle in operation in an attempt to

evaluate the power of energy harvesting and the

applicability of energy harvesting monitoring technologies

under the circumstance in which the thermal energy

and vibration energy are generated.

[email protected]

82-31-460-5248

Transactions of the Korea Society of Mechanical Engineers B

Vol. 35 No. 9

2011. 9


Journal Info.

1-20A Feasibility Study on the Energy Harvesting Technology for the Real Time Monitoring System of the Railroad Vehicle

onitoring System of the Railroad Vehicle

Load CasesRail Vehicle

- 21 -

Jae-Hoon Kim This study aimed to replace the current discontinuous

rail monitoring system by applying “Plug and Play”

technology to rail system monitoring to enable

real-time monitoring, and by confirming on-condition

maintenance efficiency and reliability. It examined a

wireless sensor monitoring system which uses SAW

(Surface Acoustic Wave) technology to monitor

temperature changes in the axle box bearing of

railroad vehicles during operation. The results of the

experiment were compared with HDB measurements

to confirm the reliability of the real-time monitoring

results measured on vehicles during operation.

[email protected]

82-31-460-5248

Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering: Sensor Systems and Software

Vol. 57 No. 2

2011. 10


Journal Info.

1-21A Study on the Wireless Onboard Monitoring System for Railroad Vehicle Axle Bearings Using the SAW Sensor

Monitoring System of the Railroad Vehicle

Load CasesRail Vehicle

- 22 -

Jeong-Guk Kim The lock-in thermography was employed to evaluate the

integrity of railway bogies. Prior to the actual application

on railway bogies, in order to assess the detectability of

ko주 flaws, the calibration reference panel was prepared

with various dimensions of artificial flaws. The panel was

composed of structural steel, which was the same material

with actual bogies. Through lock-in thermography

evaluation the optimal frequency of heat source was

determined for the best flaw detection. Based on the

defects information, the actual defect assessments on

railway bogie were conducted with different types of

railway bogies, which were used for the current operation.

In summary, the defect assessment results with

thermography method showed a good agreement as

compared with the conventional inspection techniques.

Moreover, it was found that the novel infrared

thermography technique could be an effective way for the

inspection and the detection of surface defects on bogies

since the infrared thermography method provided rapid and

non-contact mode for the investigation of railway bogies

[email protected]

Journal of the Korean Society for Nondestructive Testing

Vol. 31 No. 2

2011. 4


Journal Info.

1-22Integrity Evaluation of Railway Bogie Using Infrared Thermography Technique

- 23 -

Jeong-Guk Kim The tensile fracture behavior of polymer matrix

composite materials was investigated with the aid of

a nondestructive evaluation (NDE) technique. The

materials, E-glass fiber reinforced epoxy matrix

composites, which are applicable to bogie materials

in railway vehicles to reduce weight, were used for

this investigation. In order to explain stress-strain

behavior of polymer matrix composite sample, the

infrared thermography technique was employed. A

high-speed infrared (IR) camera was used for in-situ

monitoring of progressive damages of polymer matrix

composite samples during tensile testing. In this

investigation, the IR thermography technique was

used to facilitate a better understanding of damage

evolution, fracture mechanism, and failure mode of

polymer matrix composite materials during monotonic

loadings.

[email protected]

82-31-460-5518


Vols. 452-453

2011. 1


Journal Info.

1-23Analysis of Fracture Behavior in Polymer Matrix Composites by Infrared Thermography

- 24 -

Jung-Seok Kim We evaluated the stress-reduction effect for different

shapes of a composite adherend with or without a

spew fillet. Six different single-lap joint specimens

were modeled and assessed using nonlinear finite

element analysis. Moreover, we investigated the effect

of the stiffness ratio of the adherend and adhesive. The

single-lap joint with normal tapering had the highest

stress values, and the single-lap joint with reverse

tapering and a spew fillet had the lowest stress

values. The composite adherends with higher stiffness

had lower stress values, and the adhesives with

lower stiffness had lower stress values.

[email protected]

82-31-460-5663

Transactions of the Korea Society of Mechanical Engineers A

Vol. 35 No. 3

2011. 3


Journal Info.

1-24End-Shape Effect for Stress Concentration Reduction of Composite Single-Lap Bonded Joint

- 25 -

Jung-Seok Kim In this study, the stress reduction effect was

evaluated for GFRP/Mg single lap bonded joints

according to six different adherend shapes. Six

different types of the single lap joint specimen were

modeled and assessed using geometrically nonlinear

finite element analysis. Moreover, three dimensional

effect of stress distribution for the different adherend

shapes was investigated. From the analysis, the

dissimilar single lap bonded joint with the normal

tapering and without the spew fillet (model 2)

showed the highest stress values. In contrast, the

peel stress values of both the square ended

adherends with the spew fillet (model 3) and the

reverse tapered adherends with the spew fillet (model

5) were 65.8% and 65.5% lower than the reference

model.

[email protected]

82-31-460-5663


Vol. 14 No. 2

2011. 4


Journal Info.

1-25Stress Reduction Methods of GFRP/Mg Single Lap

Bonded Joints : Finite Element Analysis

- 26 -

Jong-Woon Kim This article deals with a problem of setting

reliability targets of the railroad systems where the

punctuality target is given to the operator and a

penalty is imposed for the year when the target is

not met. The operator should set the reliability

targets of the railroad system and sub-systems

because the reliability affects the expected number of

years when the penalty is imposed. This paper

presents a procedure for setting the service reliability

target and equations to calculate the expected number

of years when the penalty is imposed and the

probability that the operator should pay the penalty

per year according to the mean kilometer between

service failures of the railroad system and

sub-systems.

[email protected]

82-31-460-5222


Vol. 14 No. 1

2011. 2

Setting the Service Reliability Target for Meeting

the Punctuality Requirement of the Railroad System

1-26

Abstract

Journal Info.

First Author

- 27 -

Jong-Woon Kim In this paper, a method is proposed to evaluate a

number of alternatives for light-weight rolling

stock recommended from experts in rolling stock

and to decide an optimal alternative. At first,

many customer needs from various fields in

railroad are drawn and weights of customer needs

are decided by AHP. Secondly, technical

requirements that should be real specifications for

light-weight rolling stock are set and weights of

technical requirements are decided by QFD.

Finally, we evaluate some proposed alternatives

and conclude an optimal alternative of light-weight

rolling stock with TOPSIS.

[email protected]

82-31-460-5222


Vol. 14 No. 6

2011. 12

A Study on Evaluating System Performance for Light-Weight Rolling Stock

1-27

Abstract

Journal Info.

Corresponding Author

- 28 -

Hee-Min Noh In this paper, noise source localization of the Korean

high speed train was conducted by using delay and

sum beamforming method of a microphone array. At

first, the microphone array having irregular

configuration was designed and the resolution of

which was analyzed from parameters such as 3-dB

bandwidth and maximum side-lobe level. After the

demonstration, the microphone array was applied on

the high speed train and noise localization of the

high speed train driving at 300 km/h was performed

successfully.

[email protected]

82-31-460-5564


Vol. 14 No. 6

2011. 12


Journal Info.

1-28Designing a Microphone Array System for Noise Measurements on High-Speed Trains

- 29 -

Jung-Won Seo Rolling contact fatigue damages on the surface of

rail such as head check, squats are one of growing

problems. Squats are originated from the white

etching layer (WEL) or the dent on rail surface and

accompanied with dark spots including cracks.

Another form of rail surface damage, known as

"Ballast imprint" has become apparent. This form of

damage is associated with ballast particles becoming

trapped between the wheel and the surface of rail.

In this study, we have investigated whether the

ballast imprint is an initiator of head check type

cracks using the twin disc test and Finite element

analysis. The tests were conducted using specimens

with artificial defects. FE analysis were used to

investigate stresses and strains in subsurface of

defects. The test results show that cracks initiate and

propagate in dents larger than a certain size.

[email protected]

82-31-460-5210

Procedia Engineering

Vol. 10 2011. 6


Journal Info.

1-29Effects of Surface Defects on Rolling Contact Fatigue of Rail

- 30 -

Min-Hwan Ok A number of sensor networks may produce a huge

amount of data, and there has been a necessity the

data are processed in a single system. However the

viewing or navigating toward data interested has not

been evolved suitably because of the overwhelming

volumes of sensor data. This work introduces a data

browsing technique from distributed databases of

sensor data condensed according to semantics shared

among servers. Web links of a colored presentation

could enhance the view of sensor data indexed along

a hierarchy from distributed databases in the

geographic regions.

[email protected]

82-31-460-5287

Communications in Computer and Information Science

Vol. 206

2011. 9


Journal Info.

1-30Hierarchical Views for Distributed Databases of Semantically Condensed Data through Web Links to Sensor Data

- 31 -

Min-Hwan Ok The popular Social Network Service, SNS, induces

an open system for collaboration. A data exchange

system is opened without any grant as a Computer-

supported Cooperative-work tool for Computer-Aided

Engineering via Web interface. The SNS plays the

role for security instead. SNS is advantageous in

recruiting members adequate to the cooperative work,

and this open system could be a good workplace

under the paradigm of convergence.

[email protected]

82-31-460-5287

Communications in Computer and Information Science

Vol. 167

2011. 6


Journal Info.

1-31A Web Data Exchange System for Cooperative Work in CAE

- 32 -

Min-Hwan Ok Vehicles are becoming smart by their equipments

with sensors and actuators. The equipment would

report the detected malfunction status or monitored

faulty part to the driver, and it should report that to

a sort of a traffic control center as the defective car

might require a professional support. It is preferable

to transmit the collected data after reducing the

amount data. In this work, an abbreviation method is

proposed to preserve the substitutes of data probably

significant. The abbreviation reduces the amount of

data to be transmitted and stored, by abbreviating

the data into substitutes remained useful to the

calculations in detecting malfunction status or

monitoring faulty part.

[email protected]

82-31-460-5287

Lecture Notes in Computer Science

Vol. 6724

2011. 5


Journal Info.

1-32An Abbreviate Representation for Semantically Indexing of Physically Massive Data Out of Sensor Networks on the Rove

- 33 -

Sung-Cheol Yoon This paper describes the results of structural analysis

and loading test of a bogie frame. The purpose of

the analysis and test is to evaluate the safety and

functionality of the bogie frame under maximum

load. The bogie system consist of the bogie frame,

suspensions, wheel-sets, a brake system and a

transmission system. Of these components, the bogie

frame is the major component subjected to the

vehicle and passenger loads. The evaluation method

used the JIS E 4207 specifications throughout the

FEM analysis and static load test. The test results

have shown the bogie frame to be safe and stable

under design load conditions.

[email protected]

82-31-460-5512


Vols. 452-453

2011. 1


Journal Info.

1-33A Study on the Fracture Test in Running System of Railway

- 34 -

Hyuk-Jin Yoon An I type steel girder was assembled with a

concrete upper plate and then placed on two

roller supports. Four vertical load actuators

were laid on the upper plate to add the

vertical load. A single mode optical fiber was

attached on the surface of the lower flange

of a composite steel girder bridge with a

length of 39 m. Longitudinal strain distribution

of a composite steel girder bridge is

monitored directly using optical fibre sensor

system based on Brillouin frequency shift

dependency of the strain applied on the

optical fiber. Brillouin scattering signal is

generated through the Brillouin optical

correlation domain analysis at a selected

location. Strain data were acquired at 195

points with the interval of 20 cm over the

full range. From the strain data over the

entire length of the composite steel girder

bridge, the strain distribution shape was

shown when the vertical load was added on

the bridge.

[email protected]

82-31-460-5565


Vol. 10

2011. 1


Journal Info.

1-34Strain Monitoring of Composite Steel Girder Bridge Using Distributed Optical Fibre Sensor System

- 35 -

Dong-Hyong Lee Because most fatigue cracks in wheel and rail take

place by rolling contact of wheel and rail in railroad

industry it is critical to understand the rolling contact

phenomena, expecially or the three-dimensional situation.

This paper presents an approach to steady-state

rolling contact problem of three-dimensional contact

bodies with or without tangential force, based on the

finite element method. The steady-state conditions are

controlled by the applied relative slip and tangential

force. The three-dimensional distribution of tangential

traction and contact stresses on the contact surface

are investigated. Results show that the distribution of

tangential traction and contact stresses on the contact

surface varies rapidly as a result of the variation of

stick slip region. The tangential traction is very close

in form to carter's distribution

[email protected]

82-31-460-5246

Journal of the Korean

Society for Precision Engineering

Vol. 28 No. 5

2011. 5


Journal Info.

1-35Three-Dimensional Steady-State Rolling Contact Analysis Using Finite Element Method

- 36 -

Dong-Hyong Lee Because most fatigue cracks in wheel and rail take

place by rolling contact between wheel and rail in

railway industry it is critical to understand the

rolling contact phenomena, especially for the

three-dimensional situation. In this paper the

steady-state and transient rolling contact problem of

three-dimensional elastic bodies has been studied.

The transient conditions were controlled by the

applied relative slip. Th variation of tangential

traction and stick-slip region on rolling contact

surface were obtained using the finite element

method. The three-dimensional distribution of

tangential traction and contact stresses on the contact

surface are investigated. Results show that the

distribution of tangential traction and contact stresses

on the contact surface varies rapidly as a result of

the variation of stick-slip region. The tangential

traction is very close in form to Carter's distribution

that contact region divided into stick and slip region.

The contact stress at the leading edge is greater than

at the trailing edge and the transient distance

increases with small slip.

[email protected]

82-31-460-5246


Vol. 10

2011. 6


Journal Info.

1-36Three-Dimensional Transient Rolling Contact Analysis of Similar Elastic Cylinders

- 37 -

Chan-Woo Lee Curve squealing of inter-city railway vehicle is a

noise with high acoustic pressure and rather narrow

frequency spectra. This noise turns out to be very

annoying for the people living in the neighborhood

of locations and the passenger in railway vehicle

where this phenomenon occurs. Squealing is caused

by a self-exited stick-slip oscillation in the wheel-rail

contact. Curve squeal noise of railway vehicles that

passed by a factor of the speed limit, so to

overcome in order to improve running performance

is one of the largest technology. In the present

paper, characteristic of squeal noise behavior at the

Hanvit-200 tilting train test-site. Curve squealing of

railway wheels/rail contact occurs in R400-R800

curves with a frequency range of about 4-11kHz. If

the curve is less than the radius of wheel/rail contact

엳 새 left-right noise level difference(dBA) shows a

significant effect of squeal noise were more likely.

[email protected]

82-31-460-5204


Vol. 28 No. 52011. 5


Journal Info.

1-37Influence of the Speeds on the Curve Squeal Noise of Railway Vehicles

- 38 -

Hyun-Kyu Jun Prediction of a minimum crack size for growth,

which is defined as a crack size that grows fast

enough to keep ahead of its removal by contact

wear and periodic grinding, is the most demanding

work to prevent rail from fatigue failure and develop

cost effective railway maintenance strategy. In this

study, we investigated the wheel load increment due

to a rail defect during a train ran over it, and its

effect on the minimum crack size for growth. For

this purpose, we developed simulation software based

on the Fletcher and Kapoor’'s “"2.5D”" model and

measured wheel load increment during a train passed

over a defect. A maximum contact pressure and

contact patch size were calculated by 3D FEM and

crack growth analyses were performed by varying

two of dominant contact contributors; surface friction

coefficient(0.1, 0.2, 0.3 and 0.4) and crack aspect

ratio. The minimum crack sizes for growth were

calculated from 0.29 to 1.44mm depending on the

contact conditions. They were decreasing with

increasing surface friction coefficient and decreasing

with crack aspect ratio(a/b).

[email protected]

82-31-460-5228


Vol. 28 No. 5

2011. 5


Journal Info.

1-38Prediction of Surface Crack Growth Considering the Wheel Load Increment Due to RailDefect

- 39 -

Don-Bum Choi The ergonomic design approaches are not sufficient

on the railway system especialy on the locomotives

cab in Korea. Moreover, the specifications on the

design are not provided as a legal condition. In this

study, the domestic driver's anthropometire

characterics were compared against the UIC's design

criteria used in the cab design. The problems come

from drivers physical characteristics are verified with

the rolling stock running in Korea meeting the

visitility and operability of the UIC's. These studies

including environmental factors (air conditioning,

noise, vibration, control desk layout, seats etc.) are

useful on estabilishing the design specification of the

driver's cab.

[email protected]

82-31-460-5563

Journal of the Korean Institute of PlantEngineering

Vol. 16 No. 32011. 9


Journal Info.

1-39The Study on the Locomotive Cab Design Considering Driver's Physical Characteristics in Korea

- 40 -

Soon-Woo Han Optimization of aluminum extrusion profiles of a

urban railway carbody, especially Korean EMU,

for weight reducing is discussed in this work. A

base plate of underframe and side panel of side

frame composed of double skin structures, which

are heaviest parts of urban aluminum railway

carbody are considered for optimization. Topology

optimization process is applied to get a optimized

rib structure of base plate. The thickness of ribs

and plates of the topologically optimized base plate

and the existing side panel are also optimized

through size optimization process. The results are

verified by comparing maximum vonMises stresses

and maximum deformation of the existing design

and the optimized design. It is shown that the

weight of a base plate and side panel can be

reduced by 12% and the weight of whole carbody

by 8.5%.

[email protected]

82-31-460-5537

Transactions of the Korea Society of Mechanical Engineers

Vol. 35 No. 2

2011. 2


Journal Info.

1-40

9 Weight Reducing of Aluminum Extrusion Profiles of a Railway Carbody Based on Optimization Method

- 41 -

Soon-Woo Han For railway safety, it is very important to detect

damages of rails at their early stage because any

undetected damage in a rail can break the rail and

cause a serious railway accident. In this paper,

several NDT applicable to rail inspections are

described. Major damage types in rails are discussed

first and the rail inspection technology using

conventional piezoelectric ultrasonic transducers,

which is widely adopted for damage detection of

rails, is explained. Other NDT being researched or

tested for rail inspection are also discussed as

complementary technologies to the concurrent contact

type ultrasonic inspection. Characteristics of each rail

inspection technologies are evaluated in order to

provide requirements for future development of a

new rail inspection method.

[email protected]

82-31-460-5537


Vol. 31 No. 42011. 8


Journal Info.

1-41

9 Review of Non-Destructive Evaluation Technologies

for Rail Inspection

- 42 -

Young-Sam Ham For the safety of railway it should be evaluated for

the running safety by measuring the derailment

coefficient. Although railway has run the fixed and

maintained rail, some of railway is derailed. This

report shows the results that performed the static

load test, main line running test on the basis of the

derailment theory and experience. It is executed main

line test into more than 90km/h for estimating the

curving performance and running safety of depressed

center flat car of 3-axle bogie. As the test results

could confirm the curving performance and running

safety of depressed center flat car of 3-axle bogie

from the results of the wheel unloading, lateral

force, derailment coefficient etc. Derailment coefficient

was less than 0.6 and lateral force allowance limit

and wheel load reduction ratio were enough safe.

[email protected]

82-31-460-5202


Vol. 28 No. 5

2011. 5


Journal Info.

1-42

9 Evaluation of Running Safety for Depressed Center

Flat Car of 3-axle Bogie

- 43 -

Hyun-Moo Hur To analyze the effect of wear of wheel profile on

the running stability of rolling-stock, theoretical

and experimental studies were conducted on the

profiles used in conventional lines. In experiment

using 1/5 scale model to verity the results of the

theoretical analysis, the test results of the critical

speed for worn wheel profile samples show similar

trend. In case of the conical type wheel

profile(prifile 40), the equivalent conicity is

increased with flange wear. But in case of the arc

type wheel profile(prifile 20h), the equivalent

conicity is decreased with flange wear. And the

critical speed of the bogie was inverse proportion

to the equivalent conicity. It is shown that the

variation of the crical speed with the wheel wear

could be changed according to the design concept

and wear pattern of wheel prifile. results of the

theoretical and experimental studies are discussed

here

[email protected]

82-31-460-5245


Vol. 28 No. 5

2011. 5


Journal Info.

1-43

9 Analysis on the Running Stability of Rolling-Stock

according to Wheel Profile Wear

- 44 -

Sung-Il Kim The dynamic stability under the passage of a moving train has become one of the most important issues in railway bridge designs. A precise application of the dynamic properties of a structure will lead to a precise description of the dynamic behavior of a structure under moving train loads. A railway bridge is completed with a track structure, which is composed of rail, sleeper and track (concrete or ballast). A track structure can change the modal properties of the railway bridge, through the contribution of stiffness as well as mass effects. Consequently, the critical speed of the train that gives rise to the resonance behavior should be also changed, with or without the track. In the present study, a twin I-shaped steel composite girder bridge was fabricated as a test specimen, and modal testing was carried out with the installation of non-ballast, ballast track and concrete track. Modal tests were performed with hydraulic dynamic actuators. The natural frequencies, damping ratios and dynamic responses of each type of track structure were observed, along with the variation of magnitudes, frequencies and amplitudes of dynamic loading. From the results, the effects of a track structure on the railway bridge can be evaluated.

[email protected]

82-31-460-5354

SCIE Journal of Vibration & Control

Vol. 17 No. 12

2011. 10

Experimental Evaluations of Track Structure Effects

on Dynamic Properties of Railway Bridges

2-01

Abstract

Journal Info.

First Author

- 45 -

Myung Sagong Tunnel construction in a rock mass produces damage around the tunnel by concentration of in situ stress and by construction activity such as blasting. The generated damage changes the mechanical and hydraulic properties of the rock mass. In this study, the rock fracture and joint sliding behaviors of jointed rock masses with an opening under biaxial compression are investigated through experimental and numerical analyses. The tested rock models have a persistent joint set with dip angles of 30°, 45°, and 60° to the horizontal. Under the applied biaxial compression, tensile crack initiation and propagation are the dominant fracture behaviors around the hole in a low joint dip angle rock model (i.e. 30° to the horizontal). The propagation direction of the tensile cracks is roughly normal to the joint surface, and with propagation of tensile cracks, removable rock blocks are generated. The experimental results are simulated using PFC 2D. The numerical analysis simulates several aspects of rock mass cracking and the joint sliding processes around an opening: progressive fracture behaviors in a low joint angle rock model, abrupt initiation and propagation of tensile cracks and joint sliding in a high joint angle rock model (i.e. 60° to the horizontal), propagation of tensile cracks normal to the joint surface, generation of removable blocks in rock segments, an increase of lower hoop stress threshold inducing tensile fractures with a decrease in the joint angle, and an increase of the damage zone around the hole with a decrease in the joint angle.

[email protected]

SCIJournal of Sound and Vibration

Vol. 48

2011. 10

Experimental and Numerical Analyses of an Opening

in a Jointed Rock Mass under Biaxial Compression

2-02

Abstract

Journal Info.

First Author

- 46 -

Ju-Hwan Um Superimposition of horizontal and vertical curves

may hamper train ride comfort and running stability

and inflate maintenance costs. However, designing a

track plan without superimposed curves is difficult

owing to fixed points that have to be either avoided

because of geographical conditions or traversed so

that existing structures are utilized. This article

presents a method to optimize the alignment of

horizontal curves to enhance train ride comfort and

running stability when horizontal and vertical curves

are superimposed in the case of railway construction/

renovation. An algorithm was developed to determine

the combined range of radius–-transition curve

lengths (R −. Lt) for feasible horizontal curves that

pass fixed points; it was verified through a comparison

with Kufver’'s iterative method using Inrail software.

To determine the horizontal curves for optimal ride

comfort when horizontal and vertical (convex) curves

are superimposed under feasible R −. Lt boundary

conditions, a solution algorithm was developed using

the object function of ride comfort (PCT). Finally,

the simplified analysis method using PCT was

verified via vehicle/track interaction analysis.

[email protected]

82-31-460-5683

SCIEIMechE rail and rapid transit

Vol. 225 No. 6

2011. 11

Optimization of Alignment Considering Ride Comfort

for Superimposition of Vertical and Horizontal Curves

2-03

Abstract

Journal Info.

First Author

- 47 -

In-Kyu Rhee This paper explores an overturning failure mechanism for an existing concrete gravity pier on soft sandy soil beds in the event of a lateral push-over load. The pier had single horizontal cold joint in the middle of its height. The in-situ push-over experiments for the pier with/without vertical earth anchors between spread footing and rock beds showed different failure patterns against lateral load condition. In the unanchored system, no flexural cracking at the cold joint of the concrete pier developed, and the deviatoric stress of the soil underneath the compression heel of spread footing was exceeded the limit of shear failure criteria locally. This leads to a global overturning failure by rotational lift of the pier-footing system but relatively less stresses in the pier itself. While a lateral load is persistently increased in the anchored system, successive flexural cracking failure at cold joint was observed even after a local shear failure of the soils. The redistribution of stress equilibrium between thesoil and the pier structure was continuously achieved as long as the tensile action of the anchor cable is active. The modified Drucker-Prager cap plasticity for sandy soil and the exponential tension softening/compression hardening laws for plain concrete were used in the nonlinear analyses. This study includes a discussion of the differences in the failure sequences of both unanchored and anchored systems in terms of their deviatoric/hydrostatic stress trajectories of selective soil/concrete elements undergoing a staggered local failure process.

[email protected]

82-31-460-5369

SCIESoil Mechanics and Foundation Engineering

Vol. 48 No. 5

2011. 11

Lateral Overturning Failures of Old Concrete

Gravity Pier on Sandy Soils

2-04

Abstract

Journal Info.

First Author

- 48 -

Seung-Yup Jang The purpose of the present study is to explore the

diffusion characteristics of cracked concrete according

to the width of cracks. Major test variables include

crack width, concrete strength, fly ash addition, and

maximum aggregate size. The diffusion characteristics

have been measured by steady-state migration test.

The present study indicates that the diffusion

coefficients do not increase with increasing crack

widths up to the so-called “threshold crack width.”

The threshold crack width for diffusion is found to

be around 55–}80 μm. Above this threshold value,

the diffusion coefficients start to increase with crack

width. A composite model with the introduction of

“crack geometry factor” was derived to identify the

diffusion coefficient in cracked concrete. It was

shown that the crack geometry factor ranges from

0.067 to 0.206. Finally, the effects of concrete

strength, fly ash addition and maximum aggregate

size on diffusion coefficients are also discussed.

[email protected]

SCICement and Concrete Research

Vol. 41 No. 1

2011. 1

Effect of Crack Width on Chloride Diffusion Coefficients

of Concrete by Steady-State Migration Tests

2-05

Abstract

Journal Info.

First Author

- 49 -

Seung-Yup Jang The Korean urban maglev project was initiated with

the intention of building a commercial line by 2012.

An optimized guideway has been proposed and

relevant tests are currently being conducted. However,

the Dynamic Amplification Factor (DAF) for the

maglev guideway has yet to be determined. As the

maglev load is distributed rather than concentrated,

further examination of dynamic behavior is required.

The objective of this study was to identify the DAF

of the proposed urban maglev guideway via

moving-load analyses. For this purpose, a full-scale

guideway girder test and a field test were conducted to

identify the modal properties. A finite element model

was then developed and verified against test results.

Finally, moving load analyses were performed up to

the maximum speed. Guideway deflection, longitudinal

stresses, and support reactions were measured for

various vehicle speeds−DAFs were thus computed. It

was found that DAFs for maglev guideways are less

than 2.5% at the maximum design speed. This implies

that dynamic amplification need not be a severe

consideration for the proposed maglev system.

[email protected]

SCIEKSCE Journal of Civil EngineeringVol.15 No.32011. 3

Experimental and Numerical Investigation on Dynamic

Amplification Factors of an Urban Maglev Guideway

2-06

Abstract

Journal Info.

Corresponding Author

- 50 -

Tae-Hoon Koh It is a fact that the straightening of track alignment is one of the undoubted ways to improve the train speed on conventional lines, while that requires huge investment resources. Therefore, the operation of a tilting train as well as the minimum improvement of track is suggested as an effective and economical alternative way for the speed-up of conventional lines. Since a driving mechanism of tilting train is different from those of existing trains, in order to make sure its operation safety and stability on conventional line, the performance of track and roadbed must be preferentially evaluated on the conventional line. Furthermore, it is necessary to estimate the tilting -train-induced roadbed response in detail since the roadbed settlement can lead to the track deformation and even derailment. In this research, the patterns of wheel load and lateral force were monitored and analyzed through the field tests, and the derailment coefficient and degree of wheel off-loading were calculated in order to evaluate the tilting train running safety depending on the running speeds(120km~180km) on the conventional line. Moreover, roadbed pressure, settlement and acceleration were also observed as tilting-train-induced roadbed responses in order to estimate the roadbed stability depending on the running speeds. Consequently, the measured derailment coefficient and degree of wheel off-loading were satisfied with their own required limits, and all of the roadbed responses were less than those of existing high-speed train (KTX) over an entire running speed range considered in this study. As a result of this study, the tilting train which will be operated in combination with existing trains is expected to give no adverse impact on the conventional line even with its improved running speed.

[email protected]

82-31-460-5661



Vol. 14 No. 5

2011. 10


Journal Info.

2-07Tilting Train-Induced Roadbed Response on the

Conventional Line

- 51 -

Sung-Il Kim The estimation of traffic safety and passenger comfort when the train is running on the bridge is a estimation unique to the railway bridge. The standards for such estimation are included in the Eurocode, the Shinkansen design criteria, and the design guideline of the Honam High-speed railway. The items are bridge responses including vertical displacement of bridge, vertical acceleration, and slab twist. In principle, a direct estimation based on the train responses has to take place. However, the estimation based on the bridge responses can be seen as an indirect estimation procedure for the convenience of the bridge designer. First, it is general practice that traffic safety can be verified as a derailment coefficient or wheel load decrement The general method of estimating passenger comfort is to calculate the acceleration within the train car-body. Various international indexes have been presented for this method. In the present study, traffic safety and passenger comforts are estimated directly by bridge/train interaction analysis. The acceleration and wheel load decrement are obtained for the estimation of traffic safety and passenger comforts of a suspension bridge which has main span length of 300m. Also, the consideration of seismic load with simultaneous action of moving train is done for bridge/train/earthquake interaction analysis.

[email protected]

82-31-460-5354



Vol. 14 No. 1

2011. 2


Journal Info.

2-08Traffic Safety & Passenger Comforts of a

Suspension Bridge Considering Seismic Loads

- 52 -

Jin-Ho Kim When a certain magnitude earthquake occurs, serious

damage for human and properties is a major concern

for most of the subway stations which were not

applied for earthquake resistant design. Consideration

and experimental verification for ground and structural

behavior based on soil-structure interaction relation

are required to evaluate seismic performance of the

subway station as embedded structures. For 1/60

scaled subway station model, centrifuge modeling

shaking table test is performed using Kobe and North

ridge earthquakes. Compare to displacements and

moments of the underground and structure obtained

by soil response analysis and response displacement

method based on experimental results, this paper

shows how to evaluate seismic performance of

subway station.

[email protected]

82-31-460-5774

Journal of the Korea Institute for Structural Maintenance inspection

Vol. 15 No. 3

2011. 5


Journal Info.

2-09Centrifuge-Shaking Table Test for Seismic

Performance Evaluation of Subway Station

- 53 -

Sin-chu Yang The rail surface defects can cause the high impact load on the track and lead to the progress of the rail fatigue damage and the rail break. In case of the rail break, there is a great deal of risk for derailment, and thus the maintenance criteria for the rail surface defects are of great importance. In this study, using the dynamic train-track interaction analysis program, the impact wheel loads and rail bending stresses according to the depths of the surface defects have been calculated with the input data of the rail surface irregularities measured at 43 spots with surface defects in the ballasted track of high-speed railway. Considering the irregularity of track geometry, the allowable limits of wheel load and rail bending stress have been set, and the maintenance criteria for the rail surface defects was suggested by analyzing the relationship of the maximum values of wheel load and rail bending stress versus depth and width of rail surface defect. The analysis results suggest that the allowable depth of the irregularities is determined approximately 0.2mm from the limit of the impact wheel load.

[email protected]

82-31-460-5301



Vol. 14 No. 6

2011. 12


Journal Info.

2-10Investigation of the Maintenance Criteria for the Rail Surface Defects in High-Speed Railways

- 54 -

Sin-chu Yang In this study, the methodology to determine the upper limit for stiffness of rail pad for the ballasted and concrete track in high-speed railway in the viewpoint of running safety, considering the dynamic characteristics of train and track and the operation environment. For the track irregularity, one of the most important input parameters for train-track interaction analysis, the reference vertical track irregularity PSDs(power spectral densities) for the ballasted and concrete track in a wide range of frequencies were proposed based on those presented in France and Germany and that obtained from the measured data at Kyeong-Bu 1st phase high-speed railway line. Using these reference PSD models, the input data for the vertical track irregularity data were regenerated by random generation process, and then, the wheel load reduction rates according to the stiffness of the rail pads have been calculated by the train-track interaction analysis technique. Finally, by comparing the wheel load reduction rates calculated with the derailment criteria prescribed in the Korean standards for railway vehicle safety criteria, the upper limits for the stiffness of rail pad have been proposed.

[email protected]

82-31-460-5301



Vol. 14 No. 6

2011. 12


Journal Info.

2-11 Determination of Upper Limit of Rail Pad Stiffness for Ballasted and Concrete Track of High-Speed Railway Considering Running Safety

- 55 -

Ki-Young Eum Installing the temporary bridge after excavating the

railway requires installing movable cross beam, but

as it doesn’ requires isolating the catenary or cutting

the rail, it’ applicable to double-track with frequent

operation. In this study, a displacement meter was

placed on temporary bridge to monitor the displacement

pattern in curve section (R400) completed using

temporary bridge method, and wheel load, lateral

pressure and derailment coefficient were measured to

evaluate the load imposed on track and the stability

in curve section (R400) for quantitative evaluation of

training running safety. As a result of the measurement,

when trains passing over a temporary bridge, the

maximum value of Wheel load and Lateral Force is

analyzed as the 51% and 81% of standard level

according to foreign country’ performance tests,

There is no trouble with stability analysis in Wheel

load and Lateral Force occurring. Additionally,

Wheel load and Lateral Force considered as the

safety standard are tested 49% of limiting value

regardless of trains, which the norm value quite

well, there is no problem with train running.

[email protected]

82-31-460-5680



Vol. 14 No. 3

2011. 6


Journal Info.

2-12Evaluation of Train Running Safety During Construction of Temporary Bridge on Existing Railway

- 56 -

Hee-Taek Yoon To purpose of this study is to develop the new type

of precast concrete baseplate which is only for

bimodal tram. The experiments with real size

specimens, which are hollowed precast baseplate,

prove the efficacy of new designed baseplate by

comparing with the result of RCAHEST. Through

tests progressed according to different loading

locations, the specimens show the stability by the

safety factor of 8~9. Also the results of RCAHEST

that is the nonlinear finite element method program,

appropriately estimate the occuring crack on concrete,

yielding reinforcement and ultimate behavior at

failure.

[email protected]

82-31-460-5383


Vol. 15 No. 2

2011. 3


Journal Info.

2-13An Experiment and Analysis of Precast Concrete

Baseplate on Bimodal Tram Dedicated Bridge

- 57 -

Sung-Jin Lee This is a fundamental research on use as fill

material of lightweight waste such as bottom ash and

tire shred. We carried out the test for particle size

distribution, specific gravity, density, shear strength,

permeability and vertical compression settlement,

considering water content change and temperature

effect of several waste materials. Bottom ash, which

is lighter than soils, has similar permeability and

particle size distribution to those of weathered soils.

But permeability may differ depending on the

particle size distribution. The shear strength aspect of

bottom ash and tire shred mixed materials are

similar to that of natural fill materials. In the 1-D

vertical compression settlement test, we could be

assured that bottom ash and tire shred mixed

materials showed similar compression settlement to

that of sandnunder actual vertical stress. Furthermore,

materials including bottom ash showed smaller

compression settlement than that of weathered soils

in the long-term settlement test under wetting and

freezing-thawing condition.

[email protected]

82-31-460-5072

Transactions of Korean Geotechnical SocietyVol. 27 No. 5

2011. 5


Journal Info.

2-14A Study on the Basic and Compression Characteristics of Lightweight Waste for Use as Fill Materials

- 58 -

Su-Hyung Lee In this study, computation method of tensile load

which develops in tie-bar of reinforced earth,

connection strength between tie-bar and eco-block

and shear strength of the interface between two

eco-blocks were verified by experiments. According

to the test results of connection strength test, peak

tensile load of D13 deformed bar were close to

allowable tensile load of it for situation of infill

with soil. Connection strengths of D10 and D13

deformed bars were greater than the allowable tensile

load of those respectively for situation of infill with

concrete. According to the test results of shear

strength of the interface between two eco-blocks,

shear resistance parameters, and ﾞ were

evaluated as 1.7kN/m and 27.6 respectively.

[email protected]

82-31-460-5399

Transactions of Korea Academia-Industrial Cooperation Society

Vol. 12 No. 6

2011. 6


Journal Info.

2-15An Experimental Study on Local Stability of

Eco-Block

- 59 -

Su-Hyung Lee For the safety management of tunnel, effective

measurements should be continuously carried out.

Most of sensors currently being applied for tunnels

measure only the local status, thus many of them

are needed to monitor an entire tunnel. For the

railway tunnel where trains of same conditions are

regularly operated, dynamic responses of tunnel

structure to train operations can be a good index to

estimate the deformation of tunnel structure in wide

area. Meanwhile, the electromagnetic interference

caused by overhead centenary in railway tunnel

obstructs the use of electric-based sensors. In this

study a brand new accelerometer using FBG optical

fiber sensors is developed to solve these problems.

Sensitivity and capacity of the accelerometer are

enhanced with effective structural design of its

components and verified with laboratory tests. A

case history where the developed accelerometers were

applied to a safety monitoring system of a

high-speed train tunnel is presented. The

performances of the developed accelerometers are

validated from the measured acceleration data.

[email protected]

82-31-460-5399



Vol. 14 No. 4

2011. 8


Journal Info.

2-16Development of FBG Accelerometer for Railway

Tunnel Vibration

- 60 -

Il-Wha Lee The precast production has many advantages by fast

construction period, labor-saving and high quality. In

recent years, the application of the precast product

has been increased in the earth retaining wall field.

This paper presents the results of the numerical

analysis that was carried out to evaluate the dynamic

stability of precast and prestressed earth retaining

wall under moving train load. The two-dimensional

FEM analysis was used to the numerical analyses.

The train load to act on trackbed is combined by

the real measured roughness phase angle and

quasi-static load. The dynamic stability is analysed

by the displacement, acceleration and stress under

moving train load at each specified location.

The results of the analysis show that the precast and

prestressed retaining wall has very stable capability

for the railway.

[email protected]

82-31-460-5326


Vol. 15 No. 5

2011. 9


Journal Info.

2-17Evaluation of Dynamic Stability for Structural Bar Reinforced Precast and Prestressed Retaining Wall for Moving Train Load

- 61 -

Il-Wha Lee It is difficult to clarify the dynamic response

characteristics of trackbed because of various

environmental conditions. However, track irregularity

be affected by ununiformed bearing capacity and its

dynamic response, study for dynamic response

characteristics is required to investigate the cause of

track irregularity and countermeasure. In this paper,

the response variation for dominant frequency and

vibration energy by trackbed structure and material

stiffness are investigated. The analysis section is two

layered ground structure that is comprised of

trackbed and soft rock. This structure amplifies the

energy of dominant range easily. It is evaluated to

affect track irregularity on comparing by theoritical,

analytical and empirical method for dynamic response

of the trackbed.

[email protected]

82-31-460-5326



Vol. 14 No. 2

2011. 4


Journal Info.

2-18Dynamic Response Characteristics for Two-Layered

Trackbed Structure by Train Load

- 62 -

Chan-Yong Choi In seasonal frozen areas with climatic features, which

have a temperature difference in the winter and

thawing season, changes of mechanical properties of

the soil in the zone could be seen between the

freezing and thawing surface. In particular, in soil

with many fine particles, a softening of the roadbed

usually occurs from frost and thawing actions. The

lower bearing capacity is a rapidly progressive the

softening of roadbed, and occurred a mud-pumping

by repeated loading. In this study, the three kind of

sandy soil with contents of fine particles were

conducted by directly shear box test with the number

of cyclic in freeze-thawing and the water content of

soil. Subsequently, the relationship between the shear

strength and freeze-thaw cycling time was obtained.

The shear strength was decreased with the increase

of the freeze-thaw cycling time. A shear stress

deterioration of the soil with power function modal

is proposal.

[email protected]

82-31-460-5317

Transactions of Korean Geotechnical society

Vol. 12 No. 7

2011. 7


Journal Info.

2-19Reduction of Shear Strength of Railway Roadbed

Materials with Freezing-Thawing Cycle

- 63 -

Chan-Yong Choi In this paper, it was compared the characteristics of

the stress and settlement that occur from a track on

the ground using a model test and has quantitatively

analyzed the difference based on stress path and

effect of the rotation of principal stress. Under

identical roadbed conditions, the settlement generated

by moving wheel loads were found to be 6 times

and 3 times larger than that from static loads and

cyclic loads, respectively. The deviator stress

affecting shear deformation and the length of stress

path generated by moving loads were twofold or

greater increase that those by static loads.

Furthermore, the stress path generated by moving

loads was approached more closely to

Mohr-Coulomb failure criteria compared to that by

static loads. Also, it was found that ballasted track

was occurred about 60% of maximum stress at 40°

of the rotation angle of principal stress and was

affected with rotation of principal stress with moving

wheel loading condition.

[email protected]

82-31-460-5317



Vol. 14 No. 1

2011. 2


Journal Info.

2-20A Comparative of Ground Stress with Difference of

The Fixed Point Loading and Moving Wheel Loading

- 64 -

Chan-Yong Choi In this study, it conducted a compaction quality

control test in 29 domestic construction sites and

investigated the relationship between classical method

(Cyclic Plate bearing test) and LFWD test with

subgrade materials which consist in sandy soil and

gravelly soil. According to the test results, the most

of soil types were mostly satisfied with specification

criterion and gravelly soils were easily satisfied with

values over 3 times greater than specification criterion.

In term of the correlation relation of soil modulus

with the two compaction quality control test methods,

it is shown that the sandy soil types were a good

correlation, while gravelly soil types with a high

stiffness materials were indicated less correlation.

After the compensation for stress condition, a linear

regression for elastic modulus were higher correlation.

[email protected]

82-31-460-5317


Journal of the Korean Geosynthetics Society

Vol. 10 No. 3

2011. 9


Journal Info.

2-21Evaluation of Correlation between Strain Mudulus (Ev2) and Deformation Modulus (ELFWD) Using Cyclic Plate Loading Test and LFWD

- 65 -

Chang-Young Lee This study deals with a conceptual design for a high

temperature superconductor (HTS) coil fabricated

with YBCO wire in a prototype HTS-electromagnet

(HTS-EM) model for the electromagnetic suspension

(EMS)-based Maglev. Because the size of the HTS

coil and the power it consumes during operation are

very critical factors in designing the HTS-EM, we

focused on the number of coil turns and the

operating conditions needed to generate the required

magneto-motive force (MMF) effectively. The

winding geometry of the sample HTS coil with the

largest Ic value was selected for use in this study.

To determine the operating condition corresponding

to the number of coil turns, we produced the

operating profile for the load current of DC current

source and the Ic value of HTS coil. From the

profile, the optimal number of coil turns to minimize

the operating power is determined to be in the range

of 1200 to 1400 turns. And the HTS coil should be

operated with the current of 37 to 43 A at the

cooling temperature of 73 to 76 K.

[email protected]

SCI

IEEE Tran. on Applied Superconductivity

Vol. 21 No. 3

2011. 6

Conceptual Design for HTS Coil in Superconducting

Electromagnet for Maglev

3-01

Abstract

Journal Info.

First Author

- 66 -

Chang-Young Lee This paper investigates the way in which the

levitation gap of an electromagnetic suspension

(EMS) system affects the current decay rate of

superconducting electromagnet (SC-EM) operated in

persistencecurrent mode (PCM). Using inductance

analyzed from the magnetic circuit of an EMS

model, the current decay rate caused by the variation

in the levitation gap was simulated. In order to

experimentally verify the simulation results, we

fabricated a small-scale EMS model with SC coil

operated in PCM and measured the current decay

rates at different levitation gaps. The result showed

that the presence of iron core provides a significant

benefit in the PCM performance of SC coil, but the

benefit decreased as the levitation gap increases. This

study revealed that the increased levitation gap of

the EMS model with the SC-EM could negatively

affect the design of SC-EM operated in PCM.

[email protected]

SCI

Physica C

Vol. 471 No. 21-22

2011. 11

Characteristics of Persistent-Current Mode of HTS

Coil on Superconducting Electromagnet

3-02

Abstract

Journal Info.

First Author

- 67 -

Hyung-Woo Lee In case of high-speed maglev trains, the propulsion force of their linear synchronous motor (LSM) is an essential performance element since the LSM is responsible for both the propulsion and levitation of the train. A large thrust force ripple causes vibration, noise and severe levitation disturbance during the train operation. Because of these reasons, efforts must be made to reduce the thrust ripple of the LSM for propulsion and levitation. In this study, a method to decrease the thrust force ripple that causes the noise, vibration, and levitation disturbance generated during the high-speed operation of the 700 km/h ultra-high-speed tube train’'s LSM was investigated. In this method, the module phase set shift (MPSS) was applied. If the MPSS method is applied, the position of each field magnet module of the LSM changes as much as MPSS value relative to the reference load angle. To precisely calculate the total thrust force that occurs due to the position changes, thrust force mapping (TFM) method was applied to each field magnet module, and the generated total thrust force of the LSM were accurately obtained. Through this study, a method of reducing the thrust force ripple without considerablereduction of the LSM’'s average thrust force was presented.

[email protected]

82-31-460-5426

SCIIEEE Transactions on Magnetics

Vol. 47 No. 11

2011. 11

Improvement of Thrust Force Properties of Linear Synchronous Motor for an Ultra-High-Speed Tube Train

3-03

Abstract

Journal Info.

First Author

- 68 -

Hyung-Woo Lee The interior permanentmagnet synchronousmotor

(IPMSM) is usually applied to the traction motor in

the hybrid electric vehicle and the electric vehicle

due to its high-power density and wide speed range.

In this paper, the IPMSM with concentrated winding

for a 110 cc electric motorcycle is introduced. Its

design was improved for high efficiency and a wide

speed operation range. The output characteristics

were also analyzed according to the partial magnetic

saturation of the shoe and web in many variables.

Because partial magnetic saturation affects the

harmonics and the eddy current loss of the

permanent magnet, it was confirmed that the output

characteristics of the motor significantly changed. As

a result, the new shape and the design parameters

for which the partial magnetic saturation was

considered were obtained. Higher level efficiency and

a wider operating range than with the base model

were confirmed.

[email protected]

SCIIEEE Transactions on Magnetics

Vol. 47 No. 10

2011. 10

Parameter Design of IPMSM With Concentrated

Winding Considering Partial Magnetic Saturation

3-04

Abstract

Journal Info.

First Author

- 69 -

Hyung-Woo Lee The end effect of a linear induction motor (LIM)

has been known for several decades, especially in

high speed operation. The exit part of the primary is

not dealt as extensively as the entry part because of

its minor effect. However, the exit part is one of the

keys to weaken the dolphin effect, which occurs in

high speed operation. In this paper, the concept of

the virtual primary core is introduced, and

chamfering of the primary outlet teeth is proposed to

minimize the longitudinal end effect at the exit zone.

For this, LIM for the high-speed train is designed

and analyzed by using finite element method. Results

confirm that chamfering can improve thrust

performance effectively.

[email protected]

82-31-460-5426

SCIE

Journal of Electrical Engineering & Technology

Vol. 6 No. 1

2011. 1

3-05Thrust Performance Improvement of a Linear Induction Motor


Journal Info.

- 70 -

Hyung-Woo Lee The super-speed tube train was introduced to

increase the speed of ground transportation. It

levitates magnetically and runs in a partial vacuum

tube, which significantly reduces air resistance.

However, strong magnetic force sufficient to propel

the massive train can affect the infrastructure. The

induced eddy current produces joule heat, and raises

the inside temperature of the girder, which might

lead to electrochemical corrosion on the girder,

thereby weakening its durability. In this paper, the

authors analyzed the magnetic flux and induced eddy

current in the reinforced concrete girder by using

three-dimensional FEM, particularly by varying the

number of reinforcing steels of the upper flange of

the girder to the condition of almost the same

flexural strength and reinforcing steel amount.

[email protected]

82-31-460-5426

SCIE

Journal of Electrical Engineering & Technology

Vol. 6 No. 3

2011. 5

3-06Magnetic Interference on the Infrastructure for a Super-Speed Tube Train


Journal Info.

- 71 -

Bong-Kwan Cho The primary cause of most railroad accidents is vehicle entry into railway level crossings despite warning messages. To identify drivers who violate railway level crossing regulations, vehicle license plate recognition can be applied at railway level crossings. The purpose of this paper is to present an effective method for extracting the license plate region from vehicle images taken at railway level crossings. The method proposed in this paper uses the variation in the gray-level values across the image of a license plate. For license plate region extraction, the character region is first recognized by identifying the character width and the difference between the background region and the character region. The license plate region is then extracted by finding the inter-character distance in the plate region. In addition, the license plate type is identified by the difference in the gray-level value between the background region and the character region. The proposed method is effective in solving the current challenges in extracting the license plate region from the damaged frames of license plates issued for domestic use, including new types of license plates. According to the experimental results, the proposed method yields a high extraction rate of 99.5% for vehicle license plates.

[email protected]

82-31-460-5439

SCIE


Vol. 12 No. 2

2011. 4

3-07License Plate Extraction Method for Identification of Vehicle Violations at a Railway Level Crossing


Journal Info.

- 72 -

Young Park The mold transformer is a complex and critical

component of DC substations in Metro system. In

this paper, a cost effective and intelligent condition

monitoring system for mold transformers in DC

substations was developed. This paper also provides

an overview of the management program using PD

(partial discharge) data on mold transformers. Prior

to application of the proposed system to Metro DC

substations, experiments were performed at the metro

line substation located in Seoul and presented case

studies for the use of the intelligent condition

monitoring system for mold transformer in DC

substations. The experiment results indicated that the

developing system can be need in helping mange the

risk of unexpected failure of mold type transformers.

[email protected]

82-31-460-5424

Transactions of Korea Institute of Electrical Engineers

Vol. 60 No. 9

2011. 9

3-08Implementation of a Condition Monitoring System

for Mold Transformers in DC Substations


Journal Info.

- 73 -

Young Park The objective of this paper is to discuss technologies

on assessing reliability of arc detectors by composing

a system that generates and simulates occurrence of

arc caused by loss of contact between pantographs

and contact wires in a laboratory condition. In order

to establish the arc simulator, a device that generates

light having the bandwidth of arcs that occur

between carbon-metal. The simulator was designed

under conditions of EN 50317 and simulations were

conducted using the developed device. According to

the results, it was possible to conduct certification

tests following regulations of international standards

and the precision of the simulator was satisfactory.

The proposed arc detector assessment system is

expected to enhance precision of current collection

quality performance assessment methods at

high-speed lines and conventional lines while being

referred as fundamental technologies for development

of detectors suiting international conditions.

[email protected]

82-31-460-5424


Vol. 60 No. 11

2011. 11

3-09Development of an Arc Detector Assessment System by Loss of Contact Between Pantograph and Contact Wire in Electric Railway


Journal Info.

- 74 -

Chan-Bae Park Iron fillings which were accumulated around the rail

was often the cause of abnormal signal in case of

signaling equipment using rail as transmission line.

Iron fillings were generated on curved section of

railroad due to the friction between rail and wheel,

and metro line company urged to find the way to

remove these iron fillings, because these were often

the cause of abnormal signal. Magnetic device for

trapping iron fillings around concrete slab tracks is

introduced. The characteristics of magnetic device

were analyzed using basic design and numerical

analysis method. Magnetic device for trapping iron

fillings were examined for application to the train

which were operating in commercial line.

[email protected]

82-31-460-5427



Vol. 14 No. 4

2011. 8


Journal Info.

3-10Analysis of Iron-filings Trapping Characteristics on

Concrete Slab Track using Permanent Magnet

- 75 -

Chan-Bae Park In general, it is important to operate the airgap

length uniformly for improving the system efficiency

independent of the flatness of the reaction plate in a

railway propulsion system by a linear induction

motor (LIM). And it is possible to operate the LIM

propulsion system efficiently without a change of the

LIM capacity through the airgap length control on

the sloped rail. So, in this research, authors

introduce an airgap control system to control the

airgap length which depends on the flatness of the

secondary reaction plate when the LIM is operated,

and designs a rotary small-scaled LIM and its airgap

control system before manufacturing the real system.

Then, authors analyze some characteristics of the

LIM (thrust and normal force, input current,

efficiency and power factor), and through the LIM

control modeling, authors finally analyze an effect of

the airgap-length control of the LIM by the airgap

control system.

[email protected]

82-31-460-5427


Journal of Energy and Power Engineering

Vol. 5 No. 12

2011. 12


Journal Info.

3-11A Study on an Airgap Control System in a

Rotary-small-scaled Linear Induction Motor for Railway

- 76 -

Chan-Han Bae Bimodal tram is designed to run on a dedicated path

in automatic mode using a magnetic track system in

order to realize a combination of the accessibility of

a bus and the constant regularity of a railroad. This

paper presents design and test results of the series

hybrid propulsion system of the bimodal tram on

both test track and public road, which uses CNG

(Compressed Natural Gas) engine and Lithium

polymer battery pack. This paper describes the

real-time data measuring equipment for the series

hybrid propulsion system of the bimodal tram. Using

this measurement equipment, the performance of the

prototype vehicle's driving on test track and public

road was verified and the fuel consumption and the

efficiency of CNG engine have been investigated.

[email protected]

82-31-460-5417


The Transactions of the Korean Institute of Power Electronics

Vol. 16 No. 5

2011. 10


Journal Info.

3-12Development of a Series Hybrid Propulsion System

for Bimodal Tram

- 77 -

Jong-Hyen Baek Electrical Railroads provide electric power, which

can operate vehicles, via feeder wires. And the

supplied current returns to the transformer substation

through lines and ground net. The used load current

depending on the operation of rail vehicles in the

electric railway sections returns to the substation

through a track which is a return circuit. The load

current contains harmonics because of the power

conversion equipment used in rolling stocks and such

harmonic currents should not affect train control

system. In this paper we present the test result in

order to verify that the harmonics produced by the

operation of rail vehicles in the newly built electric

railway sections can affect interlocking systems. The

test in question was performed in a linking section

that trackside equipment under railway operating

conditions and interlocking are linked in order to

identify whether or not the interlocking fitted in a

signal machine room can be affected by harmonics

according to railway operation.

[email protected]

82-31-460-5441

Transactions of Korea Academic-Industrial Cooperation Society

Vol. 12 No. 8

2011. 8


Journal Info.

3-13Harmonic Frequency Analysis of Interlocking System for Rolling Stock Operation in Electrical Railroads

- 78 -

Jong-Hyen Baek Electrical Railroads provide electric power, which

can operate vehicles, via feeder wires. And the

supplied current returns to the transformer substation

through lines and ground net. The return current,

related to signal, power and power line, and track

circuit systems, is one of the most important

component in the electric railway. Therefore, to

prevent system faults and breakdown according to

unbalance and overcurrent of the return current,

various and detailed analysis for the return current

are needed. In the paper, we present measurement

and analysis manners in real environment and

evaluate its safety. For analysis, we utilize the

measured values of return currents measured in track

circuits in electric railway. we expect that this

research plays a key role to the related fields.

[email protected]

82-31-460-5441


Vol. 12 No. 9

2011. 9


Journal Info.

3-14Analysis of Return Current for Rolling Stock

Operation on Electrical Railroads

- 79 -

Jong-Hyen Baek In this paper, for the purpose of improving the

future domestic train control systems and securing

interoperability according to the global development

trends of train control systems, we present the test

results of interoperability between wayside train

control system installed in existed line, and the

onboard train control system. Due to the

safety-critical characteristics of train systems, the site

test in the section where the wayside equipment is

installed, leads to a danger against safety. Therefore,

by way of constructing a simulation environment of

train control systems, we confirm the T/R data

systems of the equipment for interoperability and test

the interoperability by applying these systems to

onboard equipment.

[email protected]

82-31-460-5441

Journal of the Korea Entertainment Industry AssociationVol. 5 No. 1

2011. 3


Journal Info.

3-15Analysis of Interoperability Test between a Different

Kind of Train Control System

- 80 -

Yeun-Sub Byun In this paper, we propose vehicle running characteristic

simulator. The developed simulator is configured by

two induction motors which are directly coupled with

each other. One motor is to simulate the vehicle

drive and another motor is to simulate the vehicle

dynamic load including running resistance, gradient

resistance and adhesive characteristics between rail

and wheel. The running characteristics of vehicle are

modeled by numerical formulas. These are programed

by software of embedded controller. Thus, it is

possible to change several running characteristics

during the running test freely and instantly. To

evaluate the feasibility of the simulator, the

experiments on slip and adhesion coefficient are

performed. Additionally the adhesion control and

speed control of vehicle are tested with simulator.

Experimental results show that the simulator can

produce the driving characteristics similar to the

vehicle system.

[email protected]

82-31-460-5437


Vol. 60 No. 10

2011. 10

3-16Vehicle Running Characteristic Simulator

Using Induction Motor


Journal Info.

- 81 -

Yeun-Sub Byun This paper is concerned with the robustness

evaluations of the guidance controller for a bimodal

tram which is being developed by the Korea

Railroad Research Institute (KRRI). The bimodal

tram is an all-wheel steered multiple-articulated

vehicle as a new kind of transportation vehicle. This

vehicle has to be equipped with an automatic

guidance system. In [1], such a controller has been

recently proposed. However, since the performance is

affected by weight change of the vehicle due to

number of the passenger, model parameter

uncertainties depending on the state of friction and

the elasticity of the tire, and a typhoon, the

controller designed must be examined with these

conditions. As expected, because the vehicle dynamics

is highly nonlinear, for the sake of investigating the

robustness of the controller we compose two

simulation ways based on the vehicle models which

are implemented by the ADAMS and the

MATLAB/LabVIEW tool boxes. Different

uncertainties and a typhoon disturbance have been

considered for the simulation conditions. Simulation

results are shown.

[email protected]

82-31-460-5437


Vol. 60 No. 10

2011. 10

3-17Evaluations of the Robustness of Guidance Controller

for a Bimodal Tram


Journal Info.

- 82 -

Kyung-Ho Shin For the train positioning system currently applied in

high-speed MAGLEV train systems, it is classified

into absolute positioning systems which discontinuously

detect train positions, and relative positioning systems

which continuously detect train positions. In this

paper we analyze the configuration model and the

numerical model of the absolute positioning system

applied in TRANSRAPID which is a representative

high-speed MAGLEV train, and design the two

configuration models specific to the recognition

structures of absolute positioning systems. We also

verify the compatibility of the design models of

absolute positioning system through simulation using

MATLAB and propose the optimal configuration

model of absolute positioning systems for high-speed

MAGLEV train system.

[email protected]

82-31-460-5488



Vol. 14 No. 2

2011. 4


Journal Info.

3-18The Design and Analysis of Recognition Structure for Absolute Train Positioning System of High-speed Maglev Train System

- 83 -

Duc-Ko Shin The recent development of USN (Ubiquitous Sensor

Network) technology has broadened its applications

to many fields of industry. The USN technology

enables the system to monitor and control the status

of distributed sensor nodes based on the low-powered

communications. Applying the USN in the train

control domain, the operational efficiency can be

enhanced, where the reliability and the safety of the

system are the key challenges. This paper suggests

the system design for evaluating and improving the

reliability and safety of the gateway, which is a

USN component that manages the radio network

among the sensors and collects the information from

them. For this purpose, the reliability and the level

of safety integrity of a general gateway have been

predicted quantitatively and the supplementary design

has been proposed for the selected week points. The

verification on the reliability and the safety of the

improved gateway according to the related standards

has been followed. With the results of the study, the

applicability of USN gateway for train control

systems has been reviewed.

[email protected]

82-31-460-5442



Vol. 14 No. 5

2011. 10


Journal Info.

3-19A Study on the Reliability/Safety Assessment and

Improvement of USN Gateway for Train Control

- 84 -

Tea-Ki An In order to monitor internal risk factors such as fire, terror, etc. on the subway station, the surveillance systems using CCTV and various kinds of sensors have been implemented and recently, introduction of surveillance systems using an advanced IT technology, sensor network technology is tried on several areas. Since 2007, Korean government has made an effort to develop the intelligent surveillance and monitoring system, which can monitor fire, intrusion, passenger congestion, health-state of structure, etc., by using wireless sensor network technology and intelligent video analytic technique. For that purpose, this study carried out field wireless communication environment test on Chungmuro Station of Seoul Metro on the basis of Zigbee that is considered as a representative wireless sensor network before field application of the intelligent integrated surveillance system being developed, arranged and analyzed and ZigBee based wireless communication environment test results on the platform and waiting room of Chungmuro Station on this paper. Results of wireless spectrum analysis on the platform and waiting room showed that there is no radio frequency overlapped with that of Zigbee based sensor network and no frequency interference with adjacent frequencies separated 10MHz or more. As results of wireless data transmission test using ZigBee showed that data transmission is influenced by multi-path fading effect from the number and flow rate of passengers on the platform or the waiting room rather than effects from entrance and exit of the train to/from the platform, it should be considered when implementing the intelligent integrated surveillance system on the station.

[email protected]

82-31-460-5714


Vol. 12 No. 7

2011. 7


Journal Info.

3-20Performance Evaluation of Wireless Sensor Networks

in the Subway Station of Workroom

- 85 -

Tea-Ki An In this paper, the radio propagation path loss

prediction simulator in tunnel was developed. It used

a image theory method for analysing precise radio

propagation path. And it can predict radio propagation

path loss in straight and curved tunnels. The

simulator can plot realtime radio propagation paths

using various parameters which was input by user.

And it can simulate from changing transmitter and

receiver positions. The predicted path loss of

simulator was compared with the measurements in

Chunhyun tunnel and confirmed the validity.

[email protected]

82-31-460-5714


Vol. 12 No. 4

2011. 4


Journal Info.

3-21Development of a Simulator for Radio Propagation

Path Loss in Tunnel at 18GHz

- 86 -

Tea-Ki An Lots of problems are emerged on the conventional

surveillance systems at urban railway infrastructure.

Many projects and research activities have been

processing on those problems. Moreover, The interest

in Intelligent Video Surveillance System that provides

accident prevention and safe driving in urban railway

service is dramatically increasing. This paper represents

a drawback of existing studies and introduces a new

solution using RFID TAG technology to improve the

existing problems. Finally, it describes the practice

test of automatic notification system based

USN(Ubiquitous Sensor Network) for a dangerous

situation.

[email protected]

82-31-460-5714

The Institute of Webcasting Internet and Telecommunication

Vol. 11 No. 1

2011. 2


Journal Info.

3-22Intelligent Video Surveillance System using

RFID Technology

- 87 -

Jun-Ho Lee In this paper a configuration of the load evaluation

device for the tilting actuator using hydraulic power

is presented, which makes it possible to measure the

force action on the tilting actuator. It is possible to

measure only current using the conventional

electro-mechanical actuator when the bogie is in the

process of the tilting. This makes impossible to

measure the force acting on the tilting actuator. In

order to overcome this problem a kinetic mechanism

test system using hydraulic cylinder is proposed. The

system are consisted of hydraulic cylinder for the

tilting actuation, control system to control hydraulic

power, sensors to measure for force and

displacement and monitoring system for the user

interface.

[email protected]

82-31-460-5040

Transactions of the Korean Society for Noise and Vibration Engineering

Vol. 21 No. 12

2011. 12


Journal Info.

3-23

5A Study on a Configuration of the Load Characteristic Evaluation Device Using Hydraulic Power for the Analysis of the Tilting Kinetic Mechanism

- 88 -

Rag-Gyo Jeong A time based software simulator for the PRT system

operation is presented. The purpose of the simulator

is to estimate the passenger transportation performance

of the PRT system. In this paper, it is presented how

the system is modeled in the simulator to estimate

passenger transportation performance and the running

algorithm of the modeled subsystem. An application

sample is also presented to find the system's design

parameter to satisfy the transportation needs.

[email protected]

82-31-460-5725


Vol. 60 No. 11

2011.11

3-24Development of the Operation Simulator for the

PRT System


Journal Info.

- 89 -

Rag-Gyo Jeong Studies suggested an increase in the competitiveness and roles of mainline railways like speed and accessibility improvement, as a fundamental direction of the National Transport Network Plan. At this point, topics presented especially for strengthening the role of human and environment centered transportation: as to the greatly improved speed competitiveness, there are an operational speed above 180km/h ~ 200km/h and traveling within 2 ~ 3 hours among big cities. As to accessibility improvement, there are accessibility to main railway stations within 30minutes, and the improvement of accessibility, safety, eco-friendliness, amenity etc. As a part of these suggestions, field specific plans were proposed for the establishment of expressed mainline railway network in Korea such as train's, civil structures, trolley lines etc. In this paper we analyzed the conventional lines and systems to figure out whether to change details in terms of H/W of signaling system. Additionally, we reviewed the compatibility or difference of signalling system depending on train's speed. With this result, we deduced the number of virtual blocks specific to the speed of 180km/h, 200km/h and 230km/h, which were showed for the speed improvement considering each variable like blocks, braking distance etc. In this way, we suggested the railway signal system establishment plan considering safety operation.

[email protected]

82-31-460-5725


Vol. 60 No. 9

2011. 9

3-25A Study on Establishment of Signaling Systems to

Speed up Conventional Railway


Journal Info.

- 90 -

Eui-Jin Joung The Electric Multiple Unit (EMU) has many types of

door system such as sliding door, plug door etc.al,

according to customer's requirements. The sliding door

is widely used in Korea but has weak point in the

noise problem. In the low operation speed, the noise

coming from outer side of the EMU is not an

important factor. As the speed is higher than before,

noise is increased and make a problem. The main

cause of noise is the imperfect air tightness in the

EMU. The plug door system has advantages for the

noise reduction characteristic in the high speed area.

We have been developing electric plug-in door. The

door is controlled by Door Control Unit (DCU)

following the order of Automatic Train Protection

(ATP) that is a kind of train signalling system. DCU

has to simultaneously open and close the doors and

the operation of it is related to the passengers safety.

So DCU is a safety device that is important to

reliability and safety. DCU is composed of several

devices of control, motor driving, Input/Output,

communication and power. In this paper, we will

describe the functions, characteristic, requirement,

subsystem, and test results of DCU used for the

electric plug-in door.

[email protected]

82-31-460-5448

Transactions of Instituteof Electronics Engineers of Korea

Vol. 48 No. 4

2011. 7

3-26Development of Door Control Unit for the Electric

Plug-in Door of Subway Train


Journal Info.

- 91 -

Ho-Sung Jung Nowadays, in metropolitan railroad, DC feeding

system is being generally applied. In order to reduce

damages of electro-chemical corrosion caused by

stray current and leakage current, in DC feeding

system, rail is used as negative-polarity return

conductor for traction load current. However, it has

problem of rail potential increase and there are no

adequate measures to prevent it in domestic. In this

paper, we presented fundamental theory and related

standards about rail potential increase. And then, we

analyzed field testing data and simulated a variety of

operations by using PSCAD/EMTDC as an analysis

program of power system. In addition, voltage

control device is suggested to prevent accidents

caused by rail potential increase.

[email protected]

82-31-460-5116


Vol. 60 No. 3

2011. 3

3-27An Analysis on Rise of Rail Potential and A Study

on Control Method for It in DC Feeding System


Journal Info.

- 92 -

Ho-Sung Jung In DC electric railways, while an electric rail car is

driving, a part of the working current returned to the

substation through rails leaks into the ground. Such

a stray current causes railways facilities and metal

objects to corrode electrolytically. Therefore, change

of stray current needs to be monitored constantly.

But so far in domestic, the research on stray current

measuring techniques and systems adaption are

insufficient. To estimate stray current, this paper

addresses a method of monitoring the return current

that is returned into the negative pole of the

substation in real time.

[email protected]

82-31-460-5116


Vol. 60 No. 4

2011. 4

3-28A Study on the Real Time Measuring Technique of Stray Current by Using Return Current Ratio In the DC Railway System


Journal Info.

- 93 -

Ho-Sung Jung In AC feeding system, the fault location is

calculated by using ratio of current absorbed in the

neutral point of AT(Automatic Transformer) or by

measuring reactance. In this way, however, an

estimation error can be happened due to the many

reasons. In addition, for measuring currents in the

neutral point of AT, other measuring devices and

communication equipments are additionally required.

In order to solve the disadvantages, this paper

suggests a novel technique using the distribution

ratio of catenary current. The proposed technique

uses existing protective relays and measures catenary

current. With the measured data, we can calculate

the distribution ratio of catenary current and determine

fault location. Through the simulated results, we

derived the correlation between current ratio and

fault location. Using this technique, additional

equipments and expenses can be reduced. Besides,

fault location can be determined more correctly.

[email protected]

82-31-460-5116



Vol. 14 No. 5

2011. 10


Journal Info.

3-29A Study on Fault Location Estimation Technique Using the distribution Ratio of Catenary Current in AC Feeding System

- 94 -

Jong-Gyu Hwang Personnel maintaining or repairing the railway tracks

or signaling facilities around tracks may experience

the sensory disorder when doing maintenance works

at the trakside of railway for long time. In this case

personnel maintaining at the trackside may collide

with the train since they cannot recognize the

approach of motor-car although it approaches to the

vicinity of maintenance workplace because of the

sensory block phenomenon occurred due to their

long hours of continued monotonous maintenance

work. In order to prevent such motor-car accidents

that may occur because railway track workers are

unable to recognize the approaching train, the safety

alarm equipment is developed to make the approaching

motor-car send radio signals and bidirectional detection

mechanism between approaching train and trackside

personnel. It shows the possibility of utilization in

various forms of safety equipment for workers only

to the safety helmet to be worn by the maintenance

workers while using the configuration of

transmitting/receiving sides. In the paper it is

represented new alarm equipment, which is the

bone-anchored speaker-based safety helmet to be

worn by the maintenance workers.

[email protected]

82-31-460-5438


International Journal of Safety

Vol. 10 No. 1

2011. 6


Journal Info.

3-30Bidirectional Alarm Equipment for Protection for

Trackside Worker using Bone-anchored Speaker

- 95 -

Soon-Bark Kwon Particulate matter (PM) is one of the major indoor air pollutants in the subway-underground stations in Korea. Various kinds of PM removal methods such as a roll-filter, auto-washable air filter, demister, and electrostatic precipitator are applied in the air handling unit (AHU) of subway station. However, those systems are faced with operation and maintenance problems since the filter-regeneration achieved by air or water jet is often malfunctioned due to the high load of particulates. The filter material also needs periodic replacement. In this study, we designed a novel particle removal system with minimized maintenance requirement compared to above mentioned filter systems. The new system named as panel-type cyclone system was suggested and the key part of the system was developed based on the axial-flow cyclone where the air flow pattern lies on the same axis with air stream through passing the AHU. The shape of axial-flow cyclone was optimized to remove 50% of 2.5 μm-sized particulate matters with minimal pressure drop by using the tool of computational fluid dynamics. We believe that the novel axial-flow cyclone system is cost-effective and efficient way of removing particulate matters in the size range of 1–0 μm in the AHU of subway station or buildings.

[email protected]

82-31-460-5375

SCIE

Aerosol and air quality research

Vol. 11 No. 5

2011. 10


Journal Info.

4-01Novel Air Filtration Device for Building Air Handling Unit

- 96 -

Hyo-In Koh This paper is primarily aimed at investigating the excitation related factors of curve noise in urban metro lines. This study is initiated within the scope of a project on the development of an active steering bogie, which has the purpose of reducing the wear and noise caused by curves. Noise and wheel profile monitoring tests were carried out four times in 2007–008. In order to identify the excitation conditions, the frequencies are investigated which are related to the unstable dynamic behaviors of the wheel. In addition, the curve negotiation performance of a metro train was analyzed to investigate the time-domain characteristics of the creepages and creep forces caused by the curved sections. The frequency region, where the flexible dynamic behavior of a wheel is unstable and the occurrence time of the unstable dynamical behavior match well with the results of the noise measurements. The relationship between the noise generation related factors due to the lateral creepage in the contact region and the longitudinal creepage, the spin creepage could be also identified. As a new approach, the parameters related to the curve noise excitation caused by the dynamic instability of the wheel are predicted with consideration to the control concept of the active steering bogie, which is now in development. A calculation on the steering performance of an active steering bogie concept shows a promising reduction in and a stable dynamic condition of the lateral creep parameters of the inner front wheel.

[email protected]

82-31-460-5207

SCIE

Journal of Vibration & Acoustics

Vol. 133 No. 6

2011. 12


Journal Info.

4-02Instability Analysis in Curve Noise of Urban Railway

Systems for Optimal Steering Bogie Development

- 97 -

Soon-Bark Kwon A novel particle removal system for air handling unit (AHU) of subway station was evaluated experimentally. The novel system was designed in order to minimize the maintenance cost by applying axial-flow cyclones. The system consists of multiple cyclone units and dust trap. Based on our previous numerical study, it was found to be effective for removal 1~10 mm sized dust particles. In this study, we manufactured the mock-up model and evaluated the model experimentally. Liquid and solid test particles were generated for evaluating collection efficiency of the system and the pressure drop was monitored. The collection efficiency was varied from 41.2% to 85.9% with increasing the sizes of particle from 1 to 6.5 ㎛ by particle count ratio of inlet and outlet. The pressure drop was maintained constant less than 20 mmH2O. In addition, the collection efficiency was estimated by total mass for solid test particles. It was found that the collection efficiency was 65.7% by particle mass ratio of inlet and outlet. It shows that present system can replace current pre-filters used in subway HVAC system for removing particulate matters with minimal operational cost.

[email protected]

82-31-460-5375

Journal of Koreaan Society for Atmospheric Environment

Vol. 27 No. 3

2011. 6


Journal Info.

4-03Experimental Study on Particle Collection Efficiency of Axial-Flow Cyclone in Air Handling Unit

- 98 -

Soon-Bark Kwon The objective of this study is to assess a level of microbial contamination in the KTX. Investigation sites in the KTX were cabin, gateway, toilet and passenger seat. It was found that the mean concentrations of airborne bacteria and fungi were 157 CFU/㎥ and 84 CFU/㎥, respectively, in all of the investigation sites of the KTX. They did not exceed the domestic standard (800 CFU/㎥) for airborne bacteria and the guideline (150 CFU/㎥) for airborne fungi recommended by WHO. Mean levels of bacteria and fungi distributed in passenger seat were 2.6×cfu/㎠ and 3.7× , respectively. The predominant genera identified in the KTX were Bacillus, Corynebacterium, Staphylococcus and Micrococcus for bacteria and Aspergillus, Cladosporium and Penicillium for fungi, respectively. Based on identification result, the profiles of airborne bacteria and fungi in the KTX was wholly similar to those of bacteria and fungi distributed in the passenger seat.

[email protected]

82-31-460-5375

Journal of Korean Society for Indoor Environment

Vol. 8 No. 1

2011. 3


Journal Info.

4-04Investigation of Airborne Microorganism in Cabin of the KTX

- 99 -

Soon-Bark Kwon In a modern society, various type of transportation modes are utilized, among them the subway system is the one of the main transportation mode which more than 7.21 million people ride a day in Seoul. Due to the increased interests on the indoor air quality (IAQ) of underground facilities, public concerns on IAQ of subway system are increasing also. Platform screen door (PSD) recently installed at the whole stations of Seoul subway and tunnel washing-out appeared to be effective in reducing particulate matters in the platform and tunnel. However there has not been any attempt to improve IAQ of subway cabin inside. Most technologies for removing airborne particulate matters are known to be difficult to adopt on the subway cabin due to the problem of maintenance cost. Therefore, the object of this study is a practical development of cabin air cleaning system which can reduce the concentration of airborne particles and harmful gases at the same time. In this paper, we focused on the development of particle removing system utilizing a roll-filter for increasing operating time of air filter. The prototype of system was designed and manufactured based on the numerical prediction results. For rollfilter device, 5 candidate filter materials were tested in point of particle collection efficiency and pressure drop. It was found that the electrically charged filter material showed the highest performance among them.

[email protected]

82-31-460-5375



Vol. 14 No. 4

2011. 8


Journal Info.

4-05Development of Air Cleaning Roll-Filter for Improving

IAQ in Subway

- 100 -

Duck-Shin Park In this study, we have observed PM-10 and CO₂

concentration in the subway cabins and analyzed the factors affecting air quality using a multivariate statistical analysis. The measurements have been conducted at Seoul metro-politan subway lines. The results show that the mean concentration of the PM-10 and CO₂inside subway cabins is in the range of 62.6 to 108.0 ㎍/㎥ and 907 to 2,008 ppm, respectively. CO₂level in specific sections during the rush hours has exceeded air quality guidelines for public transportation, which requires designated train ventilation controls. Correlation and regression analyses of influencing factors imply that CO₂level is severely influenced by the number of passengers and PM-10 level is also correlated with the number of passengers. In particular, PM-10 level in the cabins indicates a positive correlation with outdoor PM-10 level. In addition, the PM concentration has been highly affected by the number of passengers and distance between stations.

[email protected]

82-31-460-5367


Vol. 27 No. 2

2011. 4


Journal Info.

4-06 Air Quality in the Subway Cabins of the Seoul Metropolitan Area and Analysis of Its Influencing Factors Using Multivariate Statistics

- 101 -

Duck-Shin Park This study had the aim of characteristics of PM10 in subway cabins. PM10 was measured by times of day (rush and non rush hours) and seasons with real time PM10 sampler on the subway cabins of line 7. Filter samples were collected for evaluation of their elemental composition as well as identification of major sources of PM10 using a receptor model, PMF. PM10 concentration were the highest in the winter season both in the rush and non rush hours at 152.8 ㎍/㎥, 90.2 ㎍/㎥ respectively. The PM10 concentrations in rush hour were 30 % higher compared to non rush hours. Based on the chemical information, the composition rare of inorganic elements was 52.5 %, anions were 10.2 % and others were 37.3 %. Fe was the most abundant element and significantly correlated (p<0.01) with Mn (r=0.97), Ti (r=0.91), Cr (r=0.88), Ni (r=0.89) and Cu (r=0.88). Characterized PM10 sources by PMF in the cabin were soil and road dust related sources (27.2 %), railroad related sources (47.5 %), secondary nitrate sources (16.2 %) and a Cl-factor mixed with a secondary sulfate source (9.1 %).

[email protected]

82-31-460-5367


Vol. 27 No. 5

2011. 10


Journal Info.

4-07A Study for Characteristics of PM10 in the Subway passenger cabins

- 102 -

Duck-Shin Park This paper analyzes the combustion characteristics and greenhouse gas emissions from varied heat fluxes with rice husks. In general, rice husks burnt outdoors at a lower temperature range of 300-400 ℃, which cannot assure complete combustion, thusgenerating a large volume of toxic air pollutants. A heat flux of 40 kW/m2, with a cone calorimeter, is the equivalent to the 700 ℃ of an incinerator. The test result shows that the mass reduction rate of the sample at this or at a higher temperature condition was 99.5% or higher, meaning that the sample was almost completely combusted. In this study using rice husks, the amount of carbon dioxide, which is a greenhouse gas, discharged were 1.57-3.61 kg/kg. This is as high as 10 times, than produced in other studies. When the rice husks are burnt outdoors, they are not completely combusted as the combustion temperature remains low, and the rice husk residuals are continuously being combusted in a smoldering phase which creates a large volume of carbon dioxide and carbon monoxide. Therefore, it is recommended to burn rice husks at 700 ℃ or higher to minimize the carbon dioxide and carbon monoxide emissions.

[email protected]

82-31-460-5367

Journal of Environmental Science and Engineering

Vol. 5 No. 2

2011. 2


Journal Info.

4-08A Study on the Combustion Characteristics andGreenhouse Gas Emissions from Rice Husks withVaried Heat Fluxes

- 103 -

Won-Hee Park Hot smoke test is done in a subway tunnel. Alcohol

trays of 1.0 MW and smoke generators are used for

generating hot smoke. The fans equipped with the

tunnel are successively run 9 min after smoke

generation. It is verified how hot smoke is controlled

by fans. Velocity and direction of flow, temperature

and smoke density are measured and analyzed for

smoke control performance of the tunnel with fans

and analyzed from the fire-safety-point of view.

Velocity of smoke flow is obtained by using

measured velocity and temperature at the ceiling of

the tunnel. The time when smoke-control flow is

builded up is different for the different positions.

Velocity distributions at various positions will be

used for the boundaries and the comparison data in

numerical simulations for evaluation on smoke-control

facilities of subway tunnel.

[email protected]

Journal of Korean Institute of Fire Science & Engineering

Vol. 25 No. 4

2011. 8


Journal Info.

4-09Full-Scale Test of Smoke-Control Performance of a

Subway Tunnel

- 104 -

Jae-Young Lee According to governmental policies for green growth,

the increase in the traffic volume of railroad is a

representative method to reduce total greenhouse gas

(GHG) emitted from transport. Comprehensive

assessment for the GHG emission of railroad has

been studied to compare the difference of transport

modes just in the operating step excluded the

construction step. The purpose of this study was to

evaluate GHG emissions in railroad construction

sector. The targets were some construction works for

civil, track, building, and electric system in A line.

The GHG emission source of constructing railroad

infrastructure was mainly the energy consumption of

heavy equipments. As a result, the civil construction

sector showed more than 96% of total GHG

emissions and its specific GHG emission was 2.191

ton CO2e/m. Also, the specific GHG emissions of

civil construction works were of the order:

earthworks > tunnels > bridges > station. In future,

it will be required to calculate the overall GHG

emission of railroad through life cycle approaches

including operation, maintenance and disposal step.

[email protected]

82-31-460-5388



Vol. 14 No. 3

2011. 6


Journal Info.

4-10The Evaluation of GHG Emissions in Railroad

Construction Sector

- 105 -

Cheul-Kyu Lee Concrete was identified as the significant GHG

emission source resulting from a GHG emission

analysis of railway infrastructure. An environmental

assessment method (life cycle assessment; LCA) and

low carbon railway infrastructure design strategy

development method (ECODESISGN PILOT) were

applied to develop low carbon railway infrastructure

design strategies. The railway infrastructure was

analyzed as a raw material intensive industry

emitting large amount of greenhouse gas (GHG) at

its construction stage. Therefore, in this study, it is

analyzed that current status of GHG emission at its

construction stage, and a method reducing GHG

emission of railway infrastructure is proposed. In this

study, eco-concrete, concrete aging prevention agent

and a low carbon railway route decision method

based on a need of low carbon railway infrastructure

construction technology application for green railway

development were considered..

[email protected]

82-31-460-5372



Vol. 14 No. 5

2011. 10


Journal Info.

4-11A Research on the Greenhouse Gas Emission

Reduction of Railway Structure Construction Stage

- 106 -

Yong-Jun Jang The turbulent flow and vortex shedding phenomena

around pantograph panhead of high speed train were

investigated and compared with available experimental

data and other simulations. The pantograph head was

simplified to be a square-cross-section pillar and

assumed to be no interference with other bodies. The

Reynolds number (Re) was 22,000. The LES(large

eddy simulation) of FDS code was applied to solve

the momentum equations and the Wener-Wengle wall

model was employed to solve the near wall turbulent

flow. Smagorinsky model( =0.2) was used as

SGS(subgrid scale) model. The total grid numbers

were about 9 millions and the analyzed domain was

divided into 12 multi blocks which were

communicated with each other by MPI. The

time-averaged mainstream flows were calculated and

well compared with experimental data. The

phased-averaged quantities had also a good

agreement with experimental data. The near-wall

turbulence should be carefully treated by wall

function or direct resolution to get successful

application of LES methods.

[email protected]

82-31-460-5355

Journal of Computational Fluids Engineering

Vol. 16 No. 2

2011. 6


Journal Info.

4-12Analysis of Vortex Shedding Phenomena around Pantograph Panhead for Train Using Large Eddy Simulation

- 107 -

Young-Min Cho There are many studies reporting the average carbon

dioxide levels in various indoor spaces. However,

there have been a few studies showing how carbon

dioxide concentration varied at many measurement

points in one indoor space. In this study, the

changes of indoor carbon dioxide concentration at

classroom, library, and kindergarten were reported to

find its carbon dioxide distribution change at various

locations and altitudes. The maximum carbon dioxide

concentration of the 3 sites were measured as 2,684,

2,295, and 1,526 ppm, respectively. These values

exceeded the guideline concentration of 1,000 ppm

for public places. The concentration of carbon

dioxide was higher at upper area than lower area,

and this is probably due to the rise of warm

breathing air generated from students. In the upper

area, the carbon dioxide concentration was higher at

center area than four corners. However, in the lower

area, the carbon dioxide concentration was higher at

four corners than center area. Therefore, it could be

concluded that the center of upper area is the best

place for the installation of ventilation or carbon

dioxide removal system.

[email protected]

82-31-460-5362


Vol. 27 No. 1

2011. 2


Journal Info.

4-13The Distribution Characteristics of Carbon Dioxide

in Indoor School Spaces

- 108 -

Young-Min Cho A way to adsorptively remove indoor carbon dioxide at relatively lower concentration under ambient temperature was studied. A small lab-scale carbon dioxide adsorption and desorption reactors were prepared, and 5A and 13X zeolites were packed in this reactors to investigate their adsorption and desorption characteristics. The inflow carbon dioxide concentration was controlled to 5,000 ppm, relatively higher concentration found in indoor spaces with airquality problems, by diluting carbon dioxide with nitrogen gas. The flow rate was varied as 1~5 L/min, and the carbon dioxide concentration after this reactor was constantly monitored to examine the adsorption characteristics. It was found that 5A adsorbed more carbon dioxide than 13X. A lab-scale carbon dioxide desorption reactor was also prepared to investigate the desorption characteristics of zeolites, which is essential for the regeneration of used zeolites. The desorption temperature was varied as 25~200°C, and the desorption pressure was varied as 0.1~1.0 bar. Carbon dioxide desorbed better at higher temperature, and lower pressure. 5A could be regenerated more than three times by thermal desorption at 180°C. It is required to modify zeolites for higher adsorption and better regeneration performances.

[email protected]

82-31-460-5362


Vol. 27 No. 2

2011. 4


Journal Info.

4-14Adsorption and Desorption Characteristics of Carbon

Dioxide at Low Concentration on Zeolite 5A and 13X

- 109 -

Young-Min Cho High concentration of carbon dioxide at subway

cabin is one of the serious environmental concerns

because carbon dioxide causes drowsiness, headache,

and nervelessness of passengers. Ministry of Environment

set a guideline for indoor carbon dioxide levels in

train or subway in 2007. In this study, a carbon

dioxide removal system for subway cabin was

developed and tested using a test subway cabin.

Various types of modified zeolites were used as the

adsorbent of carbon dioxide. The tested zeolites were

applied to the subway cabin, and showed high

potential to lower the indoor CO 2 level.

[email protected]

82-31-460-5362



Vol. 14 No. 1

2011. 2


Journal Info.

4-15Study on the Removal of Carbon Dioxide in the Subway Cabin Using Zeolite Type Carbon Dioxide Adsorbent

- 110 -

Jun-Ho Cho Noise barrier is generally used with welding of joint

rail for railway noise reduction in our country. But

the noise barrier for high speed railway has weak

point in low frequencies about 315Hz band. In this

study, For developing of Interference-type Noise

Reduction Device(INRD), acoustic analysis were

performed using commercial software. For verifying

the improvement in the noise reduction, noise

measurement before and after installing of INRD

were performed in Anechoic Chamber. From these

acoustic analysis and noise measurement, it was

known that developed INRD has a good noise

reduction performance and can be used efficiently

with conventional noise barrier.

[email protected]

82-31-460-5366

Journal of Environmental Impact Assessment

Vol. 20 No. 6

2011. 11


Journal Info.

4-16A Study on the Performance Test and Acoustic Design of Interference Type Noise Reduction Device for Railway Noise

- 111 -

Chan-Woo Park The system we address is a maintenance network of

repairable items where a set of bases is supported by

a centrally located repair depot and a consumable

replacement parts inventory system. If an item fails, a

replacement part must be obtained at the parts

inventory system before the failed item enters the

repair depot. The ordering policy for the parts is

the(S,Q) inventory policy. An approximation method

for this system is developed to obtain performance

measures such as steady-state probabilities of the

number of items at each site and the expected

backorders at the parts inventory system. The

proposed system is modelled as a multi-class closed

queueing network with asynchronization station and

analyzed using a product-form approximation method.

Particularly, the product-form approximation method is

adapted so that the computational effort on estimating

the parameters of the equivalent multi-class network is

minimized. In analyzing a sub-network, are cursive

method is used to solve balance equations by

exploiting the special structure of the Markov chain.

Numerical tests show that the approximation method

provides fairly good estimation of the performance

measures of interests.

[email protected]

82-31-460-5545

SCIE

Computers & Operations Research

Vol. 38 No. 11

2011. 11


Journal Info.

5-01A Multi-Class Closed Queueing Maintenance

Network Model with a Parts Inventory System

- 112 -

Sang-log Kwak According to the national railway safety plan 1

billion US$ have been invested in railway industry

every year. As a result, railway accident rate has

been reduce to half recent 6 years. Currently, Korea

has 3 kinds of national railway safety target, which

are accident fatalities, train accident rate, and

passenger fatality per passenger kilometer. Increase

of railway passengers and train operating companies

force to set up new safety target. Current safety

target cannot reflect train operator's safety activities

because they include suicide and trespass related

accidents, which are hard to be controlled by the

operators. In order to reflect to the national railway

safety plan, new safety targets are proposed in this

study.

[email protected]

82-31-460-5544


Vol. 14 No. 3

2011. 6


Journal Info.

5-02A Study on Setting Up National Railway Safety

Target

- 113 -

Kyung-Min Kim This paper considers the problem of revising train

departure time to reduce electric power consumption

of mass rapid transit (MRT) railways. The motion of

a train running between stations is divided into three

phases: traction, coasting, and deceleration phases.

The traction phase requires high electric power to

operate MRT railways. In the coasting phase, the

train moves stably by consuming little or no power.

The deceleration phase is a braking mode and

produces some electric power called regenerated

brake power owing to inertia force for the train

generated in the traction and coasting phases. The

regenerative energy can be used by other accelerating

trains within a specific range from the train and

thereby the power consumptions of train can be

reduced. We developed a mixed integer programming

model to solve the problem. To validate the

suggested model, a computational experiment was

conducted using real data from Korea Metropolitan

Subway.

[email protected]



Vol. 14 No. 2

2011. 4


Journal Info.

5-03A Study on Revising Train Departure Time for

Reducing Electric Power Consumption

- 114 -

Kyung-Min Kim This paper considers the problem of track assignment

and load planning (TALP) in railway container

terminals. We formulated this problem as a

multi-criteria mixed integer program that minimizes

the delivery time of containers in terminals while

simultaneously to minimize the make-span of

terminal operations. We also applied our model to

real-world data from the Uiwang Inner Container

Depot. Our experiments showed an improvement of

approximately 19%, which means that our model can

improve the disposal capacity of containers without

additional expansion of facilities.

[email protected]

82-31-460-5491

ICIC Express Letters

Vol. 5 No. 9

2011. 9


Journal Info.

5-04Track Assignment and Load Planning Problems in

Railway Container Terminals

- 115 -

Kyung-Min Kim This paper considers the rail crane scheduling

problem which is defined as determining the

sequence of loading/unloading container on/from a

freight train. The objective is to minimize the

weighted sum of the range of order completion time

and makespan. The range of order completion time

implies the difference between the maximum of

completion time and minimum of start time of each

customer order consisting of jobs. Makespan refers

to the time when all the jobs are completed. In a

rail freight terminal, logistics firms as a customer

wish to reduce the range of their order completion

time. To develop a methodology for the crane

scheduling, we formulate the problem as a mixed

integer program and develop three metaheuristics,

namely, genetic algorithm, simulated annealing, and

tabu search. To validate the effectiveness of heuristic

algorithms, computational experiments are done based

on a set of real life data. Results of the experiments

show that heuristic algorithms give good solutions

for small-size and large-size problems in terms of

solution quality and computation time.

[email protected]

82-31-460-5491

IE Interfaces

Vol. 24 No. 4

2011. 12


Journal Info.

5-05

Metaheuristics of the Rail Crane Scheduling Problem

- 116 -

Baek-Hyun Kim The introduction of Personal Rapid Transit (PRT)

has been widely discussed in the Korean

transportation research field. However, there is no

robust criterion to derive the throughput of cars and

passengers at PRT stations, which plays a primary

role in determining the overall capacity of PRT

systems. The present study provided a methodology

to rigorously compute the capacity for simple-serial

PRT stations with a single platform, considering

three decisive factors, i.e., the demand level of

incoming cars and outgoing passengers, the station

structure, and the operation strategy. A micro-level

simulator was developed for the analysis of station

capacity. And, by using this, station capacities were

presented for various combinations of the decisive

factors. In particular, the relationship between

capacity and station structure was investigated in

detail. Station structure is represented by the

numbers of platform berths, input queue berths, and

output queue berths. Moreover, both waive rate and

waiting time, which represent the level of passenger

service, were taken into account when the station

throughput was computed.

[email protected]

82-31-460-5443


Vol. 60 No. 12

2011. 12

5-06Analysis of PRT Station Capacity Based on Micro

Simulation


Journal Info.

- 117 -

Young-Joo Kim Nowadays many warehouses and logistics facilities

are designed based on pallet which is usually used

as unit load. But it is hard to find reliable data

about reasonable pallet size though pallet plays an

important role in through transit. This paper aims to

provide reliable data on current use and recognitions

of pallets for through transit and analyze the survey

results. The results show that less than 50% of

companies do through transit and the others are

reluctant to introduce it. Despite of merits of through

transit, various commodities and compatibility with

customers becomes obstacles to achieve through

transit. The analysis of the survey results shows that

we can overcome the above problems by introducing

additional pallets for through transit. Due to the

difficulty of management, the number of additional

pallets should be minimized.

[email protected]

82-31-460-5476

Journal of DIMA

Vol. 14 No. 2

2011. 6

5-07Analysis on Recognition and Current Use of

Pallets for Through Transit


Journal Info.

- 118 -

Young-Hoon Kim In order to minimize the maintenance cost at local

lines, Information & Communication Technology

based on-board train control system is being

developed. Unlike the central traffic control based

fixed block system, this system use a moving

block method and railway driver direct control

switch and railway crossing. The purpose of this

paper is to analyze the concerned main operational

issues are as follows: the preparation of train

operation, drivability, the role of driver and

controller, block system and cost. We defined the

role of driver and driver’s input data for train

service, and we designed the business process of

driver using UML tool. We considered the aspect

of drivability, DMI is needed to support the

braking moment for the driver and driver training

simulator. We designed the driver business process

for control of switch and railway crossing. We

analyzed the fixed block system and moving block

system to confirm the difference with the existing

operational method. The cost analysis structure is

also needed for the operation cost comparison.

[email protected]

82-31-460-5485



Vol. 14 No. 6

2011. 12


Journal Info.

5-08Analysis of Operational Issues for ICT-based

On-Board Train Control System

- 119 -

Jong-Bae Wang In order to assure the safety of train operation, a

safety function analysis corresponding hazardous

events of railway accidents and a safety requirement

review on operation & management of trains have

been performed. The preconditions and train

composition requirements such as safety principles

and functions that should be essentially considered to

enable the safety operation of Urban-Transit trains

are clearly presented. On the basis of presented train

composition requirements, a rational revise of Urban

Railway Operation Rule is proposed. It will be

helpful in accident prevention and safety

improvement for railway operation.

[email protected]

82-31-460-5541



Vol. 14 No. 1

2011. 2


Journal Info.

5-09A Study on the Train Composition Requirements

for Safety Operation of Urban-Transit

- 120 -

Woo-Dong Lee The study and techniques of system engineering have

been applied to various fields including space-air,

national defense division in advanced countries.

Korea is currently in the early stages of introducing

system engineering scheme in railway system and

national defense division restrictedly. As theory and

application of system engineering covers a wide scope,

documents management and requirement analysis

technology applied to establishment of standard and

core unit development of the research target. The

techniques which are historical management and trace

among standards for establishment of standard are

introduced using SE tools and participating agencies

shared the information by constructing of database

from all documents which are generated from the

project. Through the functional analysis of the

requirements for the intelligent station monitoring

system in basic design stage, established requirements

are verified and will be made official announcement

as standard of the intelligent station monitoring

system.

[email protected]

82-31-460-5726


Vol. 14 No. 6

2011. 12


Journal Info.

5-10A Study on the DB Establishment and Traceable Management of the Urban Transit Standardization Project

Documents

2011 KRRI Technical Papers Abstracts Electromagnetic Induction and Metallic Foil Loops ... using Permanent Magnet ... Urban Transit Standardization Project