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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society for Railway
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Journal DOI :
Korean Society for Railway
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Volume & Issues
Volume 12, Issue 6 - Dec 2009
Volume 12, Issue 5 - Oct 2009
Volume 12, Issue 4 - Aug 2009
Volume 12, Issue 3 - Jun 2009
Volume 12, Issue 2 - Apr 2009
Volume 12, Issue 1 - Feb 2009
Selecting the target year
A Study on the Compaction Characteristics of Crushed Rock-soil Mixture for Railway Subgrade
Kim, Dae-Sang ; Park, Seong-Yong ; Song, Jong-Woo ; Kim, Soo-Il ; Song, Jae-Joon ;
Journal of the Korean Society for Railway, volume 12, issue 2, 2009, Pages 183~189
The track structure of Gyungbu High Speed Railway line from Daegu to Busan is concrete track. It has a very strict specification for residual settlement because of its rigid type structural characteristics. The residual settlement of it comes from the residual settlement of the subgrade and the ground. The residual settlement of railway subgrade composed of crushed rock and soil might be major parts of total residual settlement depending on the field compaction qualities. Therefore, it is a key to minimize the residual settlement of the subgrade for a successful concrete track construction. In this paper, total 31 large scale compaction tests were performed to understand the compaction behaviors of the crushed rock-soil mixture. The test specimens were constituted with soil, crushed shale and mudstone taken from two sites under construction. The compaction tests were performed with the variations of rock types, #4 sieve passing contents, maximum particle size, and moisture contents. The influence of those factors on maximum dry unit weights of crushed rock-soil mixture was evaluated.
Development of Risk Assessment Models for Railway Casualty Accidents
Park, Chan-Woo ; Wang, Jong-Bae ; Kim, Min-Su ; Choi, Don-Bum ; Kwak, Sang-Log ;
Journal of the Korean Society for Railway, volume 12, issue 2, 2009, Pages 190~198
This study shows the developing process of the risk assessment models for railway casualty accidents. To evaluate the risks of these accidents, the hazardous events and the hazardous factors were identified by the review of the accident history and engineering interpretation of the accident behavior. The frequency of each hazardous event was evaluated from the historical accident data and structured expert judgments by using the Fault Tree Analysis (FTA) technique. In addition, to assess the severity of each hazardous event, the ETA (Event Tree Analysis) technique and other safety techniques were applied. The risk assessment models developed can be effectively utilized in defining the risk reduction measures in connection with the option analysis.
A Study on Determination Method of Radius and Transition Curve Length for Optimum Design in Curve
Um, Ju-Hwan ; Kim, Eun-Kyum ; Yang, Sin-Chu ;
Journal of the Korean Society for Railway, volume 12, issue 2, 2009, Pages 199~204
In this paper, a method for determining the boundary conditions which derived from the random obstacles on the curves was presented. A simple computer program using this method is also developed. This determination method and program can be used for a good engineering tool in optimal curve design and an Radius-transition curve length
combination within the permissible zone can be improved without any increased costs.
Estimation of Optimal Modal Split Considering the Subsidy Policy - In the Case of Dual Mode Trailer
Park, Bum-Hwan ; Kim, Chung-Soo ; Lee, Kang-Won ;
Journal of the Korean Society for Railway, volume 12, issue 2, 2009, Pages 205~211
There is need to reform the road-based logistic transportation system into the railway-based logistics transportation system in order to decrease the total social cost related with logistics transportation. And new transportation modes such as dual mode trailer (DMT) are under consideration, which are expected to decrease current market share of road. But, most of current studies about estimating economical efficiency are focused on developing the probabilistic choice model and then estimating the market share of each mode. We present an approach to compute the optimal market share of each mode in terms of total social cost. To do so, we suggest an optimization model capturing both user choice to maximize his utility and subsidy policy intended to minimize total social cost, simultaneously. Using this model, we present the optimal modal split of container freight.
A Study on the Fatigue Damage of a Railway Disc Brake Surface Due to Thermal Stress During Braking Using FEM Analysis
Joo, Se-Min ; Kwon, Yong-Sang ; Kim, Ho-Kyung ;
Journal of the Korean Society for Railway, volume 12, issue 2, 2009, Pages 212~218
In order to investigate the thermal cracking of the rolling stock brake disc, finite element analysis was conducted on the temperature distribution and thermal stress of the disc during braking. In case of initial vehicle speed of 90, 106, 120km/h, the maximum temperature on the disk surface due to braking was
, respectively. And, the maximum von-Mises stress at the disc surface was 42.4, 50.3, 57.1MPa at a speed of 90, 105, 120km/h, respectively, indicating that the stress increases with an increment in the speed. Damage fraction due to braking during one year running on the Seoul - Busan line was determined as 14.6%.
Study on the Validity of Aptitude Test under Rail Safety Act
Kim, You-Cheoun ; Jeon, Young-Seok ;
Journal of the Korean Society for Railway, volume 12, issue 2, 2009, Pages 219~229
Around two years have passed since the beginning of aptitude test required by 2006 Rail Safety Act. At this point, it is necessary to evaluate the validity of the aptitude test. Through this study, the structural system for all the tests would be overviewed, which will show the correlation among each tests or its importance. Also, although it is rough, reliability and validity of the tests would be overviewed by their retest and education materials. This would contribute, in the future, to setting up for the standard of upgrading or integrating the tests.
An Analysis on the Influence of Wheel Flange Wear on the Vibration of EMU
Hur, Hyun-Moo ; Park, Joon-Hyuk ; You, Won-Hee ; Park, Tae-Won ; Yang, Chil-Sig ;
Journal of the Korean Society for Railway, volume 12, issue 2, 2009, Pages 230~235
We have conducted an experimental study to analyze characteristics of the wheel profile wear and an influence of the wheel flange wear on the vehicle's vibration characteristics. In experiment with EMU, wheel profile wear is severe at the beginning of the commercial operation. In this stage, the variations of the wheel dimension parameters and equivalent conicity is changed rapidly. Along with a mileage of the test vehicle, the wear of the wheel flange is increased and also the vibration level of the car-body is increased. The peak-peak mean value of the body vibration is estimated as good level, but the level is approached at the limit of the good level as mileage increases. Especially, the peak-peak maximum value of the body vibration shows the distinct increase of vibration level.
A Study on Numerical Analysis of Wheel-rail Contact Points
Kang, Ju-Seok ;
Journal of the Korean Society for Railway, volume 12, issue 2, 2009, Pages 236~242
This paper presents a numerical analysis method to determine flange contact at variable wheel positions. The shapes of the wheel and rail surface functions with surface parameters. The Newton-Rhapson method for wheel-rail contact can provide fast solutions, but may not yield true values at optimization process with the condition that minimum distance is zero can time-consuming. A compound method, combining the Newton-Rhapson methods the optimization process method is proposed to provide exact solutions efficiently.
The Suitability of Toughened Glass Stem Insulator for Korea High Speed Catenary System
Lee, Gi-Chun ; Jeon, Yong-Joo ; Lee, Jong-Woo ;
Journal of the Korean Society for Railway, volume 12, issue 2, 2009, Pages 243~248
The operation of KTX in Korea has launched since 2004, which brought about a great change in railroad industry. We have acquired lots of great know-hows, especially in railroad construction and operation field. Therefore, we have been building up numerous operation skills until now. However, it was necessary to investigate some of the equipment based on our own environment because the high speed train system were totally imported. In case of Toughened Glass Stem Insulator, it was totally new type in domestic. This paper introduces estimation method and result in three different field aspect, such as an electrical field, a physical field, and environmental circumstances. First, in case of an electrical field, amplitude and a number of time for switching surge voltage data were collected. Second, in case of a physical field, amplitude and trend of vibration in to the insulator were examined. Finally, in case of environmental circumstances, flying possibility of gravel and ice clod were investigated. Also shrink and expend characteristic according to temperature were reviewed. Through this basic data, suitability for Toughened Glass Stem Insulator using in domestic high speed railway have been accumulated and estimated.
Evaluation on Insulation Performance of Traction Motors for a Hybrid Vehicle by Partial Discharge Measurement
Park, Dae-Won ; Park, Chan-Yong ; Choi, Jae-Sung ; Kil, Gyung-Suk ; Lee, Kang-Won ;
Journal of the Korean Society for Railway, volume 12, issue 2, 2009, Pages 249~253
This paper dealt with the insulation evaluation by a measurement of partial discharge(PD) on traction motors used in a hybrid vehicle. The PD method has been accepted as an effective and a non-destructive. technique to evaluate insulation performance of low-voltage electric and electronic devices. In this paper, the PD measurement system which was manufactured with a coupling network, a low noise amplifier, and an associated electronics is described. The PD measurement system has the frequency bandwidth of
at -3 [dB] and the stable sensitivity of 19 [mV/pC] for the traction motor. From the experimental results, discharge inception voltage (DIV) and apparent charge (q) were
and 105 [pC] for the used motor, and
and 84 [pC] for the new one. By comparing the DIV and q, we could evaluate the insulation condition for the traction motors.
Development and Test of Inverter for Regenerative Power of DC Traction Power Supply System
Kim, Joo-Rak ; Han, Moon-Seob ; Kim, Yong-Ki ; Kim, Jung-Hoon ;
Journal of the Korean Society for Railway, volume 12, issue 2, 2009, Pages 254~259
DC transit system has been adopted in the metropolitan area, Korea since 1974. Electric multiple (EMU) in this system always reiterates that acceleration and retardation. When EMU decelerates using electric breaking, regenerative power occurs. Regenerative power can be consumed in vicinity EMU on the same line or in resistor. If DC transit system has inverter for reusing regenerative power, Energy efficiency in DC transit system and the replacement cycle of brake shoe in EMU will be increased and dust due to mechanical braking decreased. This paper present the developed inverter for regenerative power and its test equipment. Test for developed inverter is performed at test equipment and is divided into three items, which are regeneration mode, active filter mode, and system link test.
Risk Analysis Based on Accident-Category for Railway Work Zones
Park, Mi-Yun ; Choi, Eun-Soo ; Park, Joo-Nam ; Choi, Seung-Sun ;
Journal of the Korean Society for Railway, volume 12, issue 2, 2009, Pages 260~266
The theory of risk is applied frequently in analysis of railway accidents. The aim of risk analysis is to search potential causes and contribution factors of accidents by checking the total system of construction field. This paper analyze a pattern and a cause of accident occupied in construction field, calculate risk index considering accident frequency and severity, and then provide the relative risk assessment. Based on this, this paper will provide the methodology of qualitative risk assessment guiding to reach a consistency of risk index with risk assessment.
Timetabling and Analysis of Train Connection Schedule Using Max-Plus Algebra
Park, Bum-Hwan ;
Journal of the Korean Society for Railway, volume 12, issue 2, 2009, Pages 267~275
Max-plus algebra is a nonlinear system comprised of two operations, maximization (max) and addition (Plus), which are corresponding to the addition and the multiplication in conventional algebra, respectively. This methodology is applicable to many discrete event systems containing the state transition with the maximization and addition operation. Timetable with connection is one of such systems. We present the method based on max-plus algebra, which can make up timetable considering transfer and analyse its stability and robustness. In this study, it will be shown how to make up the timetable of the urban train and analyse its stability using Max-Plus algebra.
Numerical Study on the Effects of Geosynthetic Reinforcement on the Pile-supported Embankment
Lee, Su-Hyung ;
Journal of the Korean Society for Railway, volume 12, issue 2, 2009, Pages 276~284
Recently pile-supported embankments have emerged as an optimum method when the rapid construction and strict deformation of structures are required on soft soils. Especially geosynthetic-reinforced and pile-supported (GRPS) embankments are used worldwide as they can provide economic and effective solutions. However the load transfer mechanism in GRPS embankments is very complex, and not yet fully understood. Particularly the purpose and effect of geosynthetic inclusion are ambiguous and considered as an auxiliary measure assisting the arching effect of piles. Numerical parametric study using 3D finite element method has been conducted to investigate the effect of geosynthetic reinforcement on the load transfer mechanism of GRPS embankments. Numerical results suggested that as more stiffer geosynthetic is included, arching effect decreases considerably and the load concentration to the piles mostly caused by tension effect of geosynthetic. This finding is contradictory to the common understanding that geosynthetic inclusion only enhance the efficiency of load transfer. Consequently the design parameters determined from the numerical analyses are compared with those of three existing design methods. The problems of the existing methods are discussed.
A Study on the Speech Recognition for Commands of Ticketing Machine using CHMM
Kim, Beom-Seung ; Kim, Soon-Hyob ;
Journal of the Korean Society for Railway, volume 12, issue 2, 2009, Pages 285~290
This paper implemented a Speech Recognition System in order to recognize Commands of Ticketing Machine (314 station-names) at real-time using Continuous Hidden Markov Model. Used 39 MFCC at feature vectors and For the improvement of recognition rate composed 895 tied-state triphone models. System performance valuation result of the multi-speaker-dependent recognition rate and the multi-speaker-independent recognition rate is 99.24% and 98.02% respectively. In the noisy environment the recognition rate is 93.91%.
Simulation-based Optimal Design Method for the Train Overhaul Maintenance Facility
Um, In-Sup ; Jeong, Soo-Dong ; Oh, Jung-Hun ; Lee, Hong-Chul ;
Journal of the Korean Society for Railway, volume 12, issue 2, 2009, Pages 291~301
This paper presents the optimal design and analysis method of the train overhaul maintenance facility based on the simulation. Because the train is composed of a coach or more, we design the simulation model after analyzing the operation of train into train, coach, coach's body parts and wheel parts and soon. In simulation analysis, we consider the critical (dependent) factors and design (independent) parameters for the selection of alternatives and optimal design. Therefore, Multi Criteria Decision Making (MCDM) is proposed for the selection of alternatives and optimal method in order to find the optimal design factors. The case study for the above approach is used for the electronic locomotive overhaul maintenance facility. This paper provides a comprehensive framework for the train overhaul maintenance facility design using the simulation, MCDM and optimal methods. Therefore, the method developed for this research can be adopted for other enhancements in different but comparable situation.
Analysis of Travel Behavior of Rail Passenger by Activity-based Approach: The Case of Seoul-Busan Line
Eom, Jin-Ki ;
Journal of the Korean Society for Railway, volume 12, issue 2, 2009, Pages 302~308
This paper presents a comprehensive analysis of intercity rail passengers' and travel patterns based on the 2001 Seoul-Busan rail passengers' Travel Survey. Results representing personal characteristics such as age and income seem to affect on destination the income was not seen to be a critical effect on destination choice. The variables such as travel time, transfer status, and date for travel seem to be and recreation activity. However, the destination choice would be relationship between Seoul and all four destination cities. The insights gained of an activity-based rail travel demand model.
Experimental Study of the Internal/external Pressure Variation of TTX Travelling through a Tunnel
Yun, Su-Hwan ; Kwak, Min-Ho ; Lee, Dong-Ho ; Kwon, Hyeok-Bin ; Ko, Tae-Hwan ;
Journal of the Korean Society for Railway, volume 12, issue 2, 2009, Pages 309~314
When a train enters into a tunnel, a compression wave is generated by a front nose and a expansion wave is generated by a rear tail respectively. The interaction between pressure waves and the train makes the internal and external pressure of the train change dramatically. In this paper, we had measured the internal and external pressure variations of TTX and analyzed the pressure variations as the tunnel length. Also, the rate of internal pressure variations were investigated with the current airtight condition of TTX. In short tunnels, the internal and external pressure variation were not large because the superposition of pressure waves was not happened. In long tunnels, however, the rapid and large pressure variations were shown because of the superpositions between the same sort of pressure waves, such as expansion wave and expansion wave or compression wave and compression wave. In specific length tunnels, the pressure variation and the pressure variation rates were largely lessened because the compression wave and expansion wave were superposed.
Evaluating the Performance of Freight Railway Stations Using Data Envelopment Analysis
Kim, Seong-Ho ; Oh, Suk-Moon ;
Journal of the Korean Society for Railway, volume 12, issue 2, 2009, Pages 315~320
In this paper we presents an approach to evaluating the performance of freight railway stations based on several performance indicators as an alternative to the evaluation based on single indicator. Such evaluation needs a way to weight the importance of the individual performance indicator. Data envelopment analysis (DEA) suggested by Charnes, Cooper, and Rhodes (1978) can be used to determine the weights. Using DEA we evaluate 353 freight railway stations based on four performance indicators: loading volume, unloading volume, loading revenue, unloading revenue. The evaluation results facilitates the organization's decision making by providing valuable information.
Experimental Study on Load Transfer Characteristic by Adjacent Slope Excavation in a Jointed Rock Mass
Lee, Jin-Wook ; Lee, Sang-Duk ;
Journal of the Korean Society for Railway, volume 12, issue 2, 2009, Pages 321~328
A optimal reinforcement in the joint rock slope excavation adjacent to an existing tunnel would be influenced by excavation distance from the tunnel, slope angel, and joint conditions but has been empirically determined so far. In this study, large scale model tests were conducted to find out the relationship between load translation on the excavation surface and bebavior of the tunnel according to excavation steps of the jointed rock slope. Consequently, two main parameters, joint dip and sloped angle were investigated in those model tests. From the test results, it was found that tunnel deformation was the largest one when the excavation of joints located closer to the tunnel crown or invert. Stability of the slope and the tunnel were varied in a certain excavation stage related to the angle of slope. In the future, based on results of this study the reinforcement method for the tunnel and slope safety in a jointed rock mass will be demonstrated.