• 경영과학
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• 제31권2호
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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.

• 한국구조물진단유지관리공학회 논문집
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• 제13권4호통권56호
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• pp.107-115
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• 2009

70~80년대에 다수의 고속도로 건설과 함께 축적된 고속도로 터널에 대한 설계 및 시공기술에 비하여 철도터널의 설계는 최근들어 활발하게 이루어지고 있는 상황이다. 따라서 고속도로 터널과 철도 터널의 비교시에는 다소간의 시간적인 차이가 있는 것이 사실이다. 본 논문에서는 서로 비슷한 굴착단면적을 갖고 있으나 단면형상에서 차이를 나타내는 고속도로 2차로 자연환기터널과 선로중심간격 4.3m의 복선철도 터널에 대해 동일한 조건하에서 지보재를 설치하지 않은 경우와 지보재를 설치한 경우에 대해 수치해석을 수행하여 단면형상 차이에 따른 터널 주변암반에 발생하는 주응력크기 및 축차응력 비교를 통한 터널의 안정성을 비교 분석하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.418-423
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• 2009

대부분의 역사에 개찰구와 매표소가 구비되어 있거나 탑승 검표원이 드문 국내 철도 시스템과는 달리 해외의 경우, 버스 혹은 철도차량의 각 출입문 근처에 압력센서 발판 혹은 적외선 센서 그리고 CCTV 카메라를 이용한 승객 계수 시스템이 이용 되어져 왔다. 이러한 승객 계수 시스템에 의해 수집된 정보는 요일별, 시간대별 그리고 정류소별 차량 승하차 승객 수 파악을 위한 솔루션을 제공함으로써 대규모의 차량 운영사로 하여금 효율적인 차량배치 및 불필요한 인력낭비 방지를 통한 이익창출을 가능케 할 것으로 예상된다. 본 논문에서는 철도차량 출입문 근처에 적외션 센서를 장착하여 차량 승하차 승객수를 계산하는 시스템의 특정 및 무선망 (GPS, WLAN, Cellular)과 연동시 제공되는 기타 기능들에 대해 서술하였다.

• Structural Engineering and Mechanics
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• 제90권1호
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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.

• 한국철도학회논문집
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• 제10권6호
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• pp.772-778
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• 2007

곡선통과 새마을호 열차의 마모 특성을 평가하기 위하여 다량 편성 해석모델이 사용된다. 이 모델과 ADAMS/Rail를 사용하여 마모 특성과 관련된 변수의 변화에 따른 민감도 해석이 수행된다. 저속에서 우측 차륜의 마모도와 미끄럼도가 좌측 차륜보다 높으나, 고속의 경우는 좌측 차륜이 우측 차륜보다 높다. 곡선반경의 감소에 따라 마모도와 미끄럼도가 증가한다. 완화곡선의 길이가 증가하련 마모도와 미끄럼도가 증가한다. 또한 캔트가 증가하면 마모도와 미끄럼도가 증가한다.

• 대한토목학회논문집
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• 제37권6호
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• pp.1025-1032
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• 2017

본 논문에서는 고속철도 노선 및 철도차량의 서비스수준을 정의하고 이를 감안한 철도노선 및 철도차량의 관리방안을 제시하였다. 고속철도시설의 서비스수준(LOS) 등급은 A부터 F까지 6단계로 구분하여 제안하였다. 우선, 고속철도 노선의 서비스수준을 나타내는 효과척도는 열차지연으로 정의하였다. 구체적으로는 총 지연시간과 노선이용률 간 관계를 활용하여 서비스수준을 구분하였다. 추가적으로 노선용량이용율 (V/C)이라는 효과척도도 제시되었다. 한편, 고속철도 차량의 서비스수준을 결정짓는 효과척도는 차량 내 탑승 승객밀도로 정하였다. 좌석정원을 꽉채우는 수준을 LOS "D"로 정의하고 LOS A는 LOS D의 50%, LOS B는 LOS D의 70%, LOS C는 LOS D의 90%, LOS E~F는 최대 좌석수에 입석승차수를 감안하였다. 마지막으로 정부에서 정한 목표 서비스수준을 유지할 수 있도록 철도노선과 철도차량을 관리하는 방안을 제시하였다.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제21권2호
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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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• 제26권2호
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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.

• 대한토목학회논문집
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• 제35권2호
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• pp.407-415
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• 2015

철도사업을 추진함에 있어, 지금까지 대부분의 사업은 노선과 선형계획은 엔지니어가 현장 사전조사 결과 및 지형도 등을 이용하여 한정된 수의 대안을 설정하여 분석하는 방식으로 수행되어 왔다. 본 연구에서는 유전자 알고리즘을 이용한 지능형 철도선형계획 프로그램(ei-Rail)을 개발하여, 가능한 모든 대안에 대하여 선형요소 및 공사비에 대한 평가를 가능하게 하였다. 그리고 기존에 계획된 노선에 대한 비교 평가를 통하여 기존 대안보다 사업비를 절감할 수 있을 뿐만 아니라, 이에 소요되는 비용과 시간도 단축할 수 있는 것으로 나타났다. 본 연구의 결과는 향후 국내외 철도사업 계획 수립에 소요되는 비용과 시간, 그리고 전체 사업비 절감을 가능케 함으로써 철도분야 발전에 도움이 될 수 있을 것으로 기대할 수 있다.

• 한국항공운항학회지
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• 제20권1호
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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.