• Korean Management Science Review
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• v.31 no.2
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• pp.49-63
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• 2014

With the huge concerns on the inefficiency of public enterprises, particularly a significant amount of debt, an increasing number of studies have been carried out to analyze the levels of inefficiency and investigate the causes of that inefficiency. However, very limited range of analytical methodologies have been used in the efficiency analysis and moreover, the effects of external factors have been little addressed. This study explores the efficiency of urban railway corporations in Korea by utilizing a method of stochastic frontier analysis (SFA). In particular, the potential effects of external factors including residential and floating populations of a station were statistically analyzed. A total of seven Korean urban railway corporations were selected to compare each other in terms of operational efficiency. The results present three important findings. First, the Cobb-Douglas model was found to be more valid for SFA compared to the Translog model. Second, the efficiencies of urban railway corporations in Seoul and Busan are relatively high whereas those of Daejeon and Gwangju are very low in efficiency in the area of sales revenue. In an aspect of number of transport of passengers, Gwangju Metro also showed the lowest efficiency. Third, the external factors are significantly associated with the efficiency, indicating that the efficiencies of Daejeon Metro and Gwangju Metro would increase while the efficiency of Seoul Metro would decreases when the external variables are excluded in the efficiency analysis. The results provide several meaningful implications for managers of the urban railway corporations as well as policy makers who are attempting to resolve the inefficiency problems of public enterprises.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.4 s.56
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• pp.107-115
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• 2009

The number of railway tunnel design is increasing recently compare to a great number of highway tunnel design which had increased with a lot of highway construction in the 70's and 80's. Therefore, there is more or less difference of time between highway tunnel and railway tunnel. In this paper, numerical analysis on two kinds of tunnels, such as two-forked road highway ventilation tunnel and double track railway tunnel with 4.3m of center line, in cases of with support materials condition and without support materials condition were conducted. Finally, stability of two kinds of tunnels were compared and analyzed through comparing of principal stresses and deviator stresses in the near base rock of tunnels using results of numerical analysis.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.418-423
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• 2009

Unlike domestic railway transportation system in which majority of station are equipped with gate access controller and ticket office, it has been a very common practice in overseas railway transit or railway station that they use a pressure door mat, infrared-sensors or CCTV cameras so as to automatically determine the number of passenger onboard and alight and to reflect the information to their business (i.e., deployment of vehicles and human resources). The data collected by the automatic passenger counting (APC) system provides methods how to obtain the information about the number of passenger using the vehicles on the basis of date, time and stop(station) which enables large-scaled transit company to create profits through effective vehicle deployment and management of their employees. This paper addresses the basic features of the automatic passenger counting system using infrared sensor and describes those of the extended APC system in conjunction with wireless technologies such as GPS, WLAN or Cellular network.

• Structural Engineering and Mechanics
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• v.90 no.1
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• pp.41-49
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• 2024

In recent years, China's high-speed railway (HSR) line continues to expand into seismically active regions. Analyzing the features of earthquake rail irregularity is crucial in this situation. This study first established and experimentally validated a finite element (FE) model of bridge-track. The FE model was then combined with earthquake record database to generate the earthquake rail irregularity library. The sample library was used to construct a model of desired earthquake rail irregularity based on signal processing (SFT) and hypothesis principle. Finally, the effects of random pier height and random span number on desired irregularity were analyzed. Herein, an equivalent method of calculating earthquake rail irregularities for random structures was proposed. The results of this study show that the amplitude of desired irregularity is found to increase with increasing pier height. When calculating the desired irregularity of a structure with unequal pier heights, the structure can be regarded as that with equal pier heights (taking the largest pier height). For a structure with the span number large than 9, its desired irregularity can be considered equal to that of a 9-span structure. For the structures with both random pier heights and random span number, their desired irregularities are obtained by equivalent calculations for pier height and span number, respectively.

• Journal of the Korean Society for Railway
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• v.10 no.6
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• pp.772-778
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• 2007

For the wear characteristics assessment of Saemaul train passing through curves, an analysis model for multi-car system has been developed. By using this model and ADAMS/Rail, sensitivity analyses have been conducted for the wear characteristics by changing the related parameters. At low speed, the wear number and the sliding mean of right wheel showed higher than left wheel, while those of left wheel showed higher than right wheel at high speed. According to the decrease of curve radius, the wear number and the sliding mean were increased. When the length of transition curve was increased, the wear number and the sliding mean was increased. And according to increase of cant, the wear number and the sliding mean were increased.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.6
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• pp.1025-1032
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• 2017

In this paper, the level of service (LOS) is defined for high-speed railway links and rolling stocks. Based on this LOS, how to manage high-speed railway facility is also suggested. The LOS is divided into 6 levels from A to F. The measurement of effectiveness (MOE) for railway links is derived from the relationship between a total delay time and a railway link utilization ratio. Another MOE, volume over capacity (V/C), is also proposed. On the other hand, the LOS for high-speed railway rolling stocks is based on the density of people in a rolling stock. Above all, LOS D is defined to the total number of seats. Then, LOS A is 50% of the LOS D, LOS B is 70% of the LOS D, LOS C is 90% of the LOS D and LOS D~F is defined as the maximum seats and standing people at the level of each. Finally, a method to manage high-speed railway links and rolling stocks is proposed in order to keep the level of service at the target by the government.

• Journal of The Korea Institute of Healthcare Architecture
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• v.21 no.2
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• pp.35-43
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• 2015

Purpose: A large number of the mobility impaired have increasingly used the railway station, so the application of UD(Universal Design) on urban railway station has been interested. However, the current criteria used in domestic areas have concerned about the effective administration of railway station facilities rather than the needs of he mobility impaired. Of diverse facilities in railway station, the platform is considered as an important space due to many transportation users' riding or transfer in railway stations. Therefore, this study aims to explore the detailed criteria in adapting ideas from UD to platform within railway station. Methods: This study explores the criteria by evaluating findings from previous studies. First, all criteria related to platform in domestic and foreign areas are taken together and analyzed, and appropriate criteria first are established. Based on these, the current situation of platform facilities in railway station is evaluated. Then, the detailed criteria applicable to railway station platform are concluded, by reviewing types of the mobility impaired and principles of UD. Result: Findings from this study are as follows. First, the current criteria applied to railway station platforms lack ideas of UD, while the criteria used in foreign countries adequately reflect the ideas of UD on railway station platforms; therefore, the better criteria applicable to platform facilities in domestic railway station are necessary. Second, standard criteria used in domestic areas with newly additional criteria suggest that platform facilities should be established according to those criteria. Taken together, the better platform facilities should be provided to railway users through the application of UD to railway station platforms. Implications: For the future users in railway station platforms, the additional research on criteria of UD as well as diverse types of spaces within railway stations should have been continued.

• Smart Structures and Systems
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• v.26 no.2
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• pp.227-239
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• 2020

Despite proven effectiveness and accuracy in laboratories, the existing damage assessment based on guided ultrasonic waves (GUWs) or acoustic emission (AE) confronts challenges when extended to real-world structural health monitoring (SHM) for railway tracks. Central to the concerns are the extremely complex signal appearance due to highly dispersive and multimodal wave features, restriction on transducer installations, and severe contaminations of ambient noise. It remains a critical yet unsolved problem along with recent attempts to implement SHM in bourgeoning high-speed railway (HSR). By leveraging authors' continued endeavours, an SHM framework, based on actively generated diffuse ultrasonic waves (DUWs) and a benchmark-free condition contrast algorithm, has been developed and deployed via an all-in-one SHM system. Miniaturized lead zirconate titanate (PZT) wafers are utilized to generate and acquire DUWs in long-range railway tracks. Fatigue cracks in the tracks show unique contact behaviours under different conditions of external loads and further disturb DUW propagation. By contrast DUW propagation traits, fatigue cracks in railway tracks can be characterised quantitatively and the holistic health status of the tracks can be evaluated in a real-time manner. Compared with GUW- or AE-based methods, the DUW-driven inspection philosophy exhibits immunity to ambient noise and measurement uncertainty, less dependence on baseline signals, use of significantly reduced number of transducers, and high robustness in atrocious engineering conditions. Conformance tests are performed on HSR tracks, in which the evolution of fatigue damage is monitored continuously and quantitatively, demonstrating effectiveness, adaptability, reliability and robustness of DUW-driven SHM towards HSR applications.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.2
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• pp.407-415
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• 2015

The railway route and alignment planning have been executed with a limited number of alternatives based on the site pre-survey and the topographic map. This study developed an intelligent railway alignment planning program (ei-Rail) which can derive all the considerable design alternatives and provide the data for the alternative evaluation such as constructions cost, operation cost, and etc. According to the comparisons with prevailing planned railway projects, the time and cost for planning can be reduced as well as the construction costs. This program may contribute to the development of railway industry by reducing the time and cost for planning as well as the total project cost.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.20 no.1
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• pp.26-33
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• 2012

Competition between air transportation and railways has grown fiercer in major countries around the world with the rise of high-speed railways. In South Korea, air passenger travel has been rapidly decreasing since the initial launch of the Seoul-Pusan KTX line in 2004 and second opening that followed in 2010. Further expansion of the high-speed railway is expected. At present, research efforts to verify the validity of constructing an underwater express railway tunnel between Ho-nam and Jeju Island are taking place. Considering the possible high speed railway connection between Seoul and Jeju Island, this thesis has analyzed the choice behavior of existing passengers of the major and low-cost carriers. For this, Stated Preference (SP) research has been performed for three variables, including fare, travel time and the number of runs, to estimate the substitution rate of each of the three variables. Binomial Logit Model has been estimated with the obtained data. The estimation of the model has found that airline passengers of major and low-cost carriers are willing to pay approximately 7,200 KRW and 5,000 KRW, respectively, to reduce travel time by one hour. If the number of runs in one day increases, it has been estimated that the passengers are willing to pay additional fares of about 390 KRW and 30 KRW, respectively. On the other hand, the substitution rate between the number of runs and the travel time was found to be somewhat insignificant. If the construction of the Seoul-Jeju line progresses in the future, this study could be used as preliminary data for determining fares, travel time and the number of runs.