• Proceedings of the Korean Information Science Society Conference
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• 2001.10a
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• pp.187-189
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• 2001

이동 컴퓨팅(Mobile Computing)의 상업적인 응용분야로서, 지능형 교통정보시스템(ITS)에서의 첨단 여행자 정보시스템(ATIS)이 있다. ATIS에서 가장 중요한 이동 컴퓨팅 태스크는 현재 위치에서 목적지까지의 최단 경로를 계산하는 일이다. 본 논문에서는 최단 경로 재 계산 문제에 대해서 연구하였다. 이 문제는 전자 수치 지도(topological digital road map)상의 간선(edge) 비용이 동적인 교통 상태에 따라 빈번하게 갱신되고 있는 ATIS의 동적 경로 안내 시스템(URGS)에서 발생한다. 지금까지 제안된 방법들은 처음부터 최단 경로를 재계산하거나, 또는 단지 비용의 변화가 일어난 간건 상에 있는 양 끝 노드 사이에 대해서 최단 경로를 재계산할 뿐이다. 본 논문에서는 앞서 계산된 최단 경로에 대한 정보를 이용하는 효율적인 적응형 슬라이딩 윈도우 기반의 근접 최단 경로 재 계산 방법을 제안한다.

• Proceedings of the KIPE Conference
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• 2018.11a
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• pp.127-128
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• 2018

최근 전 세계적으로 온실가스에 의한 환경 문제가 심각해짐에 따라 수송 분야에서 친환경 에너지를 사용하는 요구가 확대되고 있다. 철도분야에서도 이산화탄소 배출 통제와 더불어 추진에너지로서의 배터리의 사용을 검토하고 있고 관련된 연구가 증가하고 있다. 전기자동차에 비해 철도차량의 배터리는 대용량이 필요하며 철도운영 특성상 초기 도입 비용은 물론 유지관리 비용도 발생된다는 한계점이 있다. 본 연구에서는 배터리를 적용한 철도차량의 경제성을 높이기 위해 철도차량용 폐배터리의 재활용 방안에 대해서 연구해 보겠다. 이를 위해 현재 전기자동차분야의 폐배터리 재활용 동향에 대해 알아보고 철도차량용 배터리의 재활용 가능성을 검토해보겠다.

• Journal of Korean Society of Steel Construction
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• v.17 no.2 s.75
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• pp.227-241
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• 2005

This paper presents a practical and realistic Life-Cycle Cost (LCC) optimum design methodology for steel bridges considering the long-term effect of environmental stressors such as corrosion and heavy truck traffics on bridge reliability. The LCC functions considered in the LCC optimization consist of initial cost, expected life-cycle maintenance cost, and expected life-cycle rehabilitation costs including repair/replacement costs, loss of contents or fatality and injury losses, road user costs, and indirect socio-economic losses. For the assessment of the life-cycle rehabilitation costs, the annual probability of failure, which depends upon the prior and updated load and resistance histories, should be accounted for. For the purpose, Nowak live load model and a modified corrosion propagation model, which takes into consideration corrosion initiation, corrosion rate, and repainting effect, are adopted in this study. The proposed methodology is applied to the LCC optimum design problem of an actual steel box girder bridge with 3 continuous spans (40m+50m+40m=130m). Various sensitivity analyses are performed to investigate the effects of various design parameters and conditions on the LCC-effectiveness. From the numerical investigation, it has been observed that local corrosion environments and the volume of truck traffic significantly influence the LCC-effective optimum design of steel bridges. Thus, these conditions should be considered as crucial parameters for the optimum LCC-effective design.

• Journal of Korean Society of Transportation
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• v.27 no.4
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• pp.63-76
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• 2009

On the basis of a Stochastic Frontier Approach (SFA), this paper analyses revenue efficiencies for the same sample of Korean and Japanese railways in the papers which analyze cost efficiencies using a generalized translog functional form. The paper also compares the results of revenue efficiencies with cost efficiencies and evaluates the effects of managerial autonomy and privatization on the firm-specific efficiencies. The results show that the average estimate of revenue inefficiency is 7.02% when the term of inefficiency is assumed to be distributed as a half-normal and 6.98% as a exponential for the total sample. Also, standardized inefficiencies in revenues (7.5%) are greater than those in costs (2.1%). JR East and JR West are found to be most efficient on the revenue side and on the cost side respectively while JNR and JR Kyushu are worst efficient on the both sides. Finally, the correlations between efficiencies in revenues and costs also between efficiencies and privatization are positively correlated. The results suggest that the most independent companies, with increased managerial autonomy via privatization, are the most efficient in both revenues and costs.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.2
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• pp.1-12
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• 2017

The Seoul metropolitan transportation card's high value lies in its recording of total population movements of the public transit system. In case of recorded information on transit by bus, even though route information utilized by each passenger is accurate, the lack of passenger transfer information of the urban railway makes it difficult to estimate correct routes taken by each passenger. Therefore, pinpointing passenger path selection patterns arising in the metropolitan railway network and using this as part of a path movement estimation model is essential. This research seeks to determine that features of passenger movement routes in the urban railway system is comprised of M-similar routes with increasing number of transfer reflected as additional costs. In order to construct the path finding conditions, an M-similar route searching method is proposed, embedded with non additive path cost which appears through inclusion of the stepwise transportation parameter. As well, sensitivity of the M-similar route method based on transportation card records is evaluated and a stochastic trip assignment model using M-similar path finding is constructed. From these, link trip and transfer trip results between lines of the Seoul metropolitan railway are presented.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.6
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• pp.67-78
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• 2017

Traffic congestion cost is increasing annually. Specifically congestion caused by the CDB traffic contains more than a half of the total congestion cost. Recent advancement in the field of Big Data, AI paved the way to industry revolution 4.0. And, these new technologies creates tremendous changes in the traffic information dissemination. Eventually, accurate and timely traffic information will give a positive impact on decreasing traffic congestion cost. This study, therefore, focused on developing both recurrent and non-recurrent congestion prediction models on urban roads by adopting Recurrent Neural Network(RNN), a tribe in machine learning. Two hidden layers with scaled conjugate gradient backpropagation algorithm were selected, and tested. Result of the analysis driven the authors to 25 meaningful links out of 33 total links that have appropriate mean square errors. Authors concluded that RNN model is a feasible model to predict congestion.

• Journal of Korean Society of Transportation
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• v.27 no.3
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• pp.119-130
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• 2009

The aim of this study is to analyze the effects of DVR(Driving Video Recorder) operation on decreasing the number of traffic accidents, the cost of traffic accident claim, and the behavioral change in drivers' driving. The data for this research are obtained from taxi drivers in Busan. For this, Structural Equation Model and two-way ANOVA are employed for empirical analysis. Overall results of this study show that the number of traffic accidents of 4 taxi corporations in Busan has decreased by average 32.7 percent after using DVRs. In addition, as to the cost of taxi accident claims, it is expected that the DVR operation has a considerable effect on economic benefits of taxi corporations. Moreover, this study could make clear the difference in behaviors between DVR users and non-users, and discriminate the positive and negative impacts of the DVR operation on the drivers' driving behavior. The study quantitatively examined the indirect impact of 'attitude', 'subject norm' and 'behavioral control' factors on planned 'behavior', and the direct impact of 'behavioral control' factor on the planned 'behavior'. This study suggests that they should add the video recoding function of DVRs when operation recorder(blackbox for the car) is obligatorily set up on cars for business by traffic security law.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.1
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• pp.147-157
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• 2013

This study developed the transit transfer mode choice model aimed Daegu transit users using multinomial logit model. Dependent variables of estimating multinomial logit model were transit transfer modes such as bus to bus, bus to subway, subway to subway, bus to others, and subway to others, and explanatory variables which affect transit transfer mode choice were sex, age, occupation, handicap, transfer area, purpose of travel and travel time. Also probability regarding explanatory variables was estimated using multinomial logit model and limit marginal analysis was carried out according to explanatory variables(cost, time). In the results, indicating goodness of fit is very reasonable as ${\rho}^2$=0.354. According to the result of marginal analysis for the selection of probability, when travel time is increased, users of bus to bus and bus to subway prefer to use subway to subway. Furthermore users of bus to bus and bus to subway prefer to use bus to others and subway to others when travel cost is increased in the result of marginal analysis for the selection of probability.

• Journal of the Korean Geographical Society
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• v.51 no.1
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• pp.77-88
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• 2016

Dramatic changes have so far been made in the system of central places over the past century. The development of transport has particularly exercised principal influences on the changes of the system of central places. This paper is to examine how and why the development of transport enables such changes to take place in the system of central places, through conducting model research. This paper suggests some models that development of transport be taken as an independent variable and that the division of market area between the central places be as the development of variable. The suggested models show that the development of transport extends the market area of higher central places but reduces the market area of lower central places.

• Journal of Korean Society of Transportation
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• v.16 no.2
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• pp.77-90
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• 1998

첨단교통관리시스템, 첨단교통정보시스템, 첨단대중교통시스템, 첨단화물운송시스템, 첨단차량 및 도로시스템으로 구성된 한국형 ITS는 적절히 설계, 전개, 운용된다면, 교통체증, 연료, 비용, 공해, 사고 등의 감소와 함께 운전자의 수행도 및 효율성의 향상을 꾀할 수 있다. 그러나, 이러한 목적을 달성하기 위해서는 운전자 및 조작자의 새로운 기술과 시스템들에 대한 중요성 및 시스템의 통합이 중요한 요건으로 작용되며, 인간공학은 이러한 과정에 있어 운전자 및 시스템조작자의 물리적, 인지적 한계를 규명하고 이를 시스템 설계에 반영하는 설계 가이드라인 작성에서 실제 평가까지의 과정에 중요한 역할을 하고 있다. 즉, TMC, AVHS 등의 시스템과 함께 주요한 차내 정보시스템인 항법장치, HUD, RDS-TMC등에 걸쳐 널리 적용되고 있으며, 인간공학은 각각의 시스템뿐만 아닌 전체 ITS의 성공적인 시장성 확보와 전개에도 중요한 영향을 미치는 중요한 요인으로 간주되고 있다. 또한, ISO TC 204 등에 의해 수용되고 있는 인간공학 표준화작업은 장차 ITS의 국제시장 진출 및 산업화를 위한 중요한 문제로 대두되고 있는 실정이다. 이에 본 연구는 국내외 TS에서의 이간공학 적용 및 표준화 동향을 제시함으로써, 한국형 ITS의 인간공학 적용 및 표준화 연구를 위한 기반적인 내용의 제공과 함께, 국내의 연구 및 표준화 작업을 위한 방안을 제시한다.