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).
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.
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).
82-31-460-5663
SCI
International Journal of Impact Engineering
Vol. 38 No. 4
2011. 4
First Author Abstract
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.
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,
82-31-460-5266
SCI
Experimental Mechanics
Vol. 51 No. 6
2011. 6
First Author Abstract
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.
82-31-460-5263
SCIE
International Journal of Automotive Technology
Vol. 12 No. 3
2011. 6
Corresponding Author Abstract
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.
82-31-460-5276
SCIE
Journal of Mechanical Science and Technology
Vol. 25 No. 7
2011. 7
First Author Abstract
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.
82-31-460-5210
SCI
International Journal of Fatigue
Vol. 33 No. 2
2011. 2
First Author Abstract
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.
82-31-460-5565
SCI
NDT&E International
Vol. 33 No. 2
2011. 2
First Author Abstract
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.
82-31-460-5537
SCIE
Journal of Mechanical Science and Technology
Vol. 25 No. 8
2011. 8
First Author Abstract
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.
82-31-460-5243
Journal of KWJS
Vol. 29 No. 4
2011. 8
First Author Abstract
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.
82-31-460-5243
Journal of the Korean Society for Railway
Vol. 14 No. 2
2011. 4
Corresponding Author Abstract
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.
82-31-460-5249
Journal of the Korean Society for Precision Engineering
Vol. 28 No. 5
2011. 5
First Author Abstract
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.
82-31-460-5263
Transactions of KSAE
Vol. 19 No. 2
2011. 2
Corresponding Author Abstract
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.
82-31-460-5205
International Journal of Systems Applications Engineering & Development
Vol. 5 No. 1
2011. 2
First Author Abstract
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.
82-31-460-5205
International Journal of Systems Applications Engineering & Development
Vol. 5 No. 2
2011. 4
First Author Abstract
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.
82-31-460-5205
International Journal of Systems Applications Engineering & Development
Vol. 5 No. 1
2011. 2
First Author Abstract
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.
82-31-460-5730
Key Engineering Materials
Vols. 452-453
2011. 1
First Author Abstract
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.
82-31-460-5730
Key Engineering Materials
Vols. 452-453
2011. 1
First Author Abstract
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.
82-31-460-5248
Transactions of the Korea Society of Mechanical Engineers B
Vol. 35 No. 9
2011. 9
First Author Abstract
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.
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
First Author Abstract
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
Journal of the Korean Society for Nondestructive Testing
Vol. 31 No. 2
2011. 4
First Author Abstract
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.
82-31-460-5518
Key Engineering Materials
Vols. 452-453
2011. 1
First Author Abstract
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.
82-31-460-5663
Transactions of the Korea Society of Mechanical Engineers A
Vol. 35 No. 3
2011. 3
First Author Abstract
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.
82-31-460-5663
Journal of the Korean Society for Railway
Vol. 14 No. 2
2011. 4
First Author Abstract
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.
82-31-460-5222
Journal of the Korean Society for Railway
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.
82-31-460-5222
Journal of the Korean Society for Railway
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.
82-31-460-5564
Journal of the Korean Society for Railway
Vol. 14 No. 6
2011. 12
First Author Abstract
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.
82-31-460-5210
Procedia Engineering
Vol. 10 2011. 6
First Author Abstract
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.
82-31-460-5287
Communications in Computer and Information Science
Vol. 206
2011. 9
First Author Abstract
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.
82-31-460-5287
Communications in Computer and Information Science
Vol. 167
2011. 6
First Author Abstract
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.
82-31-460-5287
Lecture Notes in Computer Science
Vol. 6724
2011. 5
First Author Abstract
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.
82-31-460-5512
Key Engineering Materials
Vols. 452-453
2011. 1
First Author Abstract
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.
82-31-460-5565
Procedia Engineering
Vol. 10
2011. 1
First Author Abstract
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
82-31-460-5246
Journal of the Korean
Society for Precision Engineering
Vol. 28 No. 5
2011. 5
First Author Abstract
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.
82-31-460-5246
Procedia Engineering
Vol. 10
2011. 6
First Author Abstract
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.
82-31-460-5204
Journal of the Korean Society for Precision Engineering
Vol. 28 No. 52011. 5
First Author Abstract
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).
82-31-460-5228
Journal of the Korean Society for Precision Engineering
Vol. 28 No. 5
2011. 5
First Author Abstract
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.
82-31-460-5563
Journal of the Korean Institute of PlantEngineering
Vol. 16 No. 32011. 9
First Author Abstract
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%.
82-31-460-5537
Transactions of the Korea Society of Mechanical Engineers
Vol. 35 No. 2
2011. 2
First Author Abstract
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.
82-31-460-5537
Journal of the Korean Society for Railway
Vol. 31 No. 42011. 8
First Author Abstract
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.
82-31-460-5202
Journal of the Korean Society for Precision Engineering
Vol. 28 No. 5
2011. 5
First Author Abstract
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
82-31-460-5245
Journal of the Korean Society for Precision Engineering
Vol. 28 No. 5
2011. 5
First Author Abstract
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.
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.
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.
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.
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.
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.
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.
82-31-460-5661
Journal of the Korean
Journal of the Korean Society for Railway
Vol. 14 No. 5
2011. 10
First Author Abstract
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.
82-31-460-5354
Journal of the Korean
Journal of the Korean Society for Railway
Vol. 14 No. 1
2011. 2
First Author Abstract
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.
82-31-460-5774
Journal of the Korea Institute for Structural Maintenance inspection
Vol. 15 No. 3
2011. 5
First Author Abstract
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.
82-31-460-5301
Journal of the Korean
Journal of the Korean Society for Railway
Vol. 14 No. 6
2011. 12
First Author Abstract
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.
82-31-460-5301
Journal of the Korean
Journal of the Korean Society for Railway
Vol. 14 No. 6
2011. 12
First Author Abstract
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.
82-31-460-5680
Journal of the Korean
Journal of the Korean Society for Railway
Vol. 14 No. 3
2011. 6
First Author Abstract
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.
82-31-460-5383
Journal of the Korea Institute for Structural Maintenance inspection
Vol. 15 No. 2
2011. 3
Corresponding Author Abstract
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.
82-31-460-5072
Transactions of Korean Geotechnical SocietyVol. 27 No. 5
2011. 5
First Author Abstract
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.
82-31-460-5399
Transactions of Korea Academia-Industrial Cooperation Society
Vol. 12 No. 6
2011. 6
Corresponding Author Abstract
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.
82-31-460-5399
Journal of the Korean
Journal of the Korean Society for Railway
Vol. 14 No. 4
2011. 8
First Author Abstract
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.
82-31-460-5326
Journal of the Korea Institute for Structural Maintenance inspection
Vol. 15 No. 5
2011. 9
First Author Abstract
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.
82-31-460-5326
Journal of the Korean
Journal of the Korean Society for Railway
Vol. 14 No. 2
2011. 4
First Author Abstract
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.
82-31-460-5317
Transactions of Korean Geotechnical society
Vol. 12 No. 7
2011. 7
First Author Abstract
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.
82-31-460-5317
Journal of the Korean
Journal of the Korean Society for Railway
Vol. 14 No. 1
2011. 2
First Author Abstract
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.
82-31-460-5317
Journal of the Korean
Journal of the Korean Geosynthetics Society
Vol. 10 No. 3
2011. 9
First Author Abstract
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.
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.
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.
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.
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.
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
First Author Abstract
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.
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
First Author Abstract
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.
82-31-460-5439
SCIE
International Journal of Automotive Technology
Vol. 12 No. 2
2011. 4
3-07License Plate Extraction Method for Identification of Vehicle Violations at a Railway Level Crossing
First Author Abstract
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.
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
First Author Abstract
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.
82-31-460-5424
Transactions of Korea Institute of Electrical Engineers
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
First Author Abstract
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.
82-31-460-5427
Journal of the Korean
Journal of the Korean Society for Railway
Vol. 14 No. 4
2011. 8
First Author Abstract
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.
82-31-460-5427
Journal of the Korean
Journal of Energy and Power Engineering
Vol. 5 No. 12
2011. 12
First Author Abstract
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.
82-31-460-5417
Journal of the Korean
The Transactions of the Korean Institute of Power Electronics
Vol. 16 No. 5
2011. 10
First Author Abstract
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.
82-31-460-5441
Transactions of Korea Academic-Industrial Cooperation Society
Vol. 12 No. 8
2011. 8
First Author Abstract
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.
82-31-460-5441
Transactions of Korea Academic-Industrial Cooperation Society
Vol. 12 No. 9
2011. 9
First Author Abstract
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.
82-31-460-5441
Journal of the Korea Entertainment Industry AssociationVol. 5 No. 1
2011. 3
First Author Abstract
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.
82-31-460-5437
Transactions of Korea Institute of Electrical Engineers
Vol. 60 No. 10
2011. 10
3-16Vehicle Running Characteristic Simulator
Using Induction Motor
First Author Abstract
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.
82-31-460-5437
Transactions of Korea Institute of Electrical Engineers
Vol. 60 No. 10
2011. 10
3-17Evaluations of the Robustness of Guidance Controller
for a Bimodal Tram
Corresponding Author Abstract
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.
82-31-460-5488
Journal of the Korean
Journal of the Korean Society for Railway
Vol. 14 No. 2
2011. 4
First Author Abstract
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.
82-31-460-5442
Journal of the Korean
Journal of the Korean Society for Railway
Vol. 14 No. 5
2011. 10
First Author Abstract
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.
82-31-460-5714
Transactions of Korea Academic-Industrial Cooperation Society
Vol. 12 No. 7
2011. 7
First Author Abstract
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.
82-31-460-5714
Transactions of Korea Academic-Industrial Cooperation Society
Vol. 12 No. 4
2011. 4
First Author Abstract
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.
82-31-460-5714
The Institute of Webcasting Internet and Telecommunication
Vol. 11 No. 1
2011. 2
First Author Abstract
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.
82-31-460-5040
Transactions of the Korean Society for Noise and Vibration Engineering
Vol. 21 No. 12
2011. 12
First Author Abstract
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.
82-31-460-5725
Transactions of Korea Institute of Electrical Engineers
Vol. 60 No. 11
2011.11
3-24Development of the Operation Simulator for the
PRT System
First Author Abstract
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.
82-31-460-5725
Transactions of Korea Institute of Electrical Engineers
Vol. 60 No. 9
2011. 9
3-25A Study on Establishment of Signaling Systems to
Speed up Conventional Railway
First Author Abstract
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.
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
First Author Abstract
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.
82-31-460-5116
Transactions of Korea Institute of Electrical Engineers
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
Corresponding Author Abstract
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.
82-31-460-5116
Transactions of Korea Institute of Electrical Engineers
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
First Author Abstract
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.
82-31-460-5116
Journal of the Korean
Journal of the Korean Society for Railway
Vol. 14 No. 5
2011. 10
First Author Abstract
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.
82-31-460-5438
Journal of the Korean
International Journal of Safety
Vol. 10 No. 1
2011. 6
First Author Abstract
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.
82-31-460-5375
SCIE
Aerosol and air quality research
Vol. 11 No. 5
2011. 10
First Author Abstract
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.
82-31-460-5207
SCIE
Journal of Vibration & Acoustics
Vol. 133 No. 6
2011. 12
First Author Abstract
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.
82-31-460-5375
Journal of Koreaan Society for Atmospheric Environment
Vol. 27 No. 3
2011. 6
Corresponding Author Abstract
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.
82-31-460-5375
Journal of Korean Society for Indoor Environment
Vol. 8 No. 1
2011. 3
First Author Abstract
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.
82-31-460-5375
Journal of the Korean
Journal of the Korean Society for Railway
Vol. 14 No. 4
2011. 8
First Author Abstract
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.
82-31-460-5367
Journal of Koreaan Society for Atmospheric Environment
Vol. 27 No. 2
2011. 4
Corresponding Author Abstract
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 %).
82-31-460-5367
Journal of Koreaan Society for Atmospheric Environment
Vol. 27 No. 5
2011. 10
Corresponding Author Abstract
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.
82-31-460-5367
Journal of Environmental Science and Engineering
Vol. 5 No. 2
2011. 2
Corresponding Author Abstract
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.
Journal of Korean Institute of Fire Science & Engineering
Vol. 25 No. 4
2011. 8
First Author Abstract
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.
82-31-460-5388
Journal of the Korean
Journal of the Korean Society for Railway
Vol. 14 No. 3
2011. 6
First Author Abstract
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..
82-31-460-5372
Journal of the Korean
Journal of the Korean Society for Railway
Vol. 14 No. 5
2011. 10
First Author Abstract
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.
82-31-460-5355
Journal of Computational Fluids Engineering
Vol. 16 No. 2
2011. 6
First Author Abstract
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.
82-31-460-5362
Journal of Koreaan Society for Atmospheric Environment
Vol. 27 No. 1
2011. 2
First Author Abstract
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.
82-31-460-5362
Journal of Koreaan Society for Atmospheric Environment
Vol. 27 No. 2
2011. 4
First Author Abstract
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.
82-31-460-5362
Journal of the Korean
Journal of the Korean Society for Railway
Vol. 14 No. 1
2011. 2
First Author Abstract
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.
82-31-460-5366
Journal of Environmental Impact Assessment
Vol. 20 No. 6
2011. 11
First Author Abstract
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.
82-31-460-5545
SCIE
Computers & Operations Research
Vol. 38 No. 11
2011. 11
First Author Abstract
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.
82-31-460-5544
Journal of the Korean Society for Railway
Vol. 14 No. 3
2011. 6
First Author Abstract
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.
Journal of the Korean
Journal of the Korean Society for Railway
Vol. 14 No. 2
2011. 4
Corresponding Author Abstract
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.
82-31-460-5491
ICIC Express Letters
Vol. 5 No. 9
2011. 9
First Author Abstract
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.
82-31-460-5491
IE Interfaces
Vol. 24 No. 4
2011. 12
Corresponding Author Abstract
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.
82-31-460-5443
Transactions of Korea Institute of Electrical Engineers
Vol. 60 No. 12
2011. 12
5-06Analysis of PRT Station Capacity Based on Micro
Simulation
First Author Abstract
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.
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
First Author Abstract
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.
82-31-460-5485
Journal of the Korean
Journal of the Korean Society for Railway
Vol. 14 No. 6
2011. 12
First Author Abstract
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.
82-31-460-5541
Journal of the Korean
Journal of the Korean Society for Railway
Vol. 14 No. 1
2011. 2
Corresponding Author Abstract
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.
82-31-460-5726
Journal of the Korean Society for Railway
Vol. 14 No. 6
2011. 12
First Author Abstract
Journal Info.
5-10A Study on the DB Establishment and Traceable Management of the Urban Transit Standardization Project