• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.3
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• pp.1-14
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• 2008

Mass transit information should contribute many benefits to users. Especially transportation information technology is developing highly with information technology in Korea recently. Hereafter it is expected to provide customized transportation information to users individually with the advent of ubiquitous age in earnest. This public transportation information service can be realized by path finding algorithms in public transportation networks including travel and transfer attributes. In this research, multi objectives such as travel time, transfer time, and number of transfer and so on are constructed with the primary facts influencing users. Moreover, the method reducing user's path finding alternatives arbitrarily is proposed by selecting the best alternative which provides maximum utility to users among non dominated paths. Therefore, the ultimate goal of this study proposes a multi objective shortest paths finding algorithm which can take into account multiple user classes in a transit network with multiple travel modes. The proposed algorithm is demonstrated based on the two case studies - a small toy network and the large-scaled Seoul Metropolitan subway network.

• Journal of Korean Society of Transportation
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• v.23 no.5 s.83
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• pp.7-14
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• 2005

Traffic congestion causes enormous social costs as well as loss of travel time and waste of energy. Though the Seoul metropolitan government implemented various forms of transportation policies such as urban road pricing and public transportation reform, traffic volume which across the Seoul metropolitan borders have greatly increased because of housing land development in suburban area. The purpose of this study is to estimate individual's willingness-to-pay(WTP) for extensive implementation of congestion pricing through policy-mix with bus rapid transit(BRT) system. So the field survey interviews carried out. The empirical analysis was done with priority given to the following two topics; derivation of individual WTP and prior evaluation of policy effect from the equity aspect. To estimate individual WTP, we adopted contingent valuation method (CVM). The former is to estimate individual WTP for respondent's maintaining his/her transit pattern when he/she is faced with congestion pricing by using compensating variation(CV) concept. And, the latter aims at evaluating policy effect from the equity aspect by calculating the Proportion of WTP to average income using WTP in income bracket for policy scenarios.

• Journal of Korean Society of Transportation
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• v.26 no.5
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• pp.163-174
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• 2008

The conventional four-step travel demand model is still widely used as the state-of-practice in most transportation planning agencies even though it does not provide reliable estimates of travel demand. In order to improve the accuracy of travel demand estimation, implementing an alternative approach would be critical as much as acquiring reliable socioeconomic and travel data. Recently, the role of travel demand model is diverse to satisfy the needs of microscopic analysis regarding various policies of travel demand management and traffic operations. In this context, the activity-based approach for travel demand estimation is introduced and a case study of developing a spatial-temporal activity presence-based approach that estimates travel demand through forecasting number of people present at certain place and time is accomplished. Results show that the spatial-temporal activity presence-based approach provides reliable estimates of both number of people present and trips actually people made. It is expected that the proposed approach will provide better estimates and be used in not only long-term transport plans but short-term transport impact studies with respect to various transport policies. Finally, in order to introduce the spatial-temporal activity presence-based approach, the data such as activity-based travel diary and land use based on geographic information system are essential.

• Journal of Korean Society of Transportation
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• v.25 no.2 s.95
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• pp.121-132
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• 2007

This paper addressed the issue of a generalized cost model for transit assignment. The model composed of walk time, waiting time (including transfer waiting time), line-haul time, transfer walk time, and fare. The weights of each component were supposed to be calculated using the stated preference (SP) data, which were collected prudently in order to reflect reality. The marginal rate of substitution and wage rate were applied to calculate the weights. The results showed that the weight of walking time per in-vehicle travel time (IVTT) was 1.507, the weight of waiting time (per IVTT) was 1.749, that of transfer time (per IVTT) was 1.474, and that of fare (per IVTT) was 1.476 for trips between inner-city areas in Seoul. Weights for each component were identified as 1.871, 1.967, 1.015, and 0.857, respectively, for trips between Seoul and Gyeonggi. Statistical significance existed between two cases and each variable was also statistically significant. Transit assignment using the relative weights estimated in this study was implemented to analyze the travel index in a macroscopic and quantitative basis. The results showed that average total travel times were 30.23 minutes and 63.29 minutes and average generalized costs were 2,510 won and 3,880 won for trips between inner-city areas in Seoul and between Seoul and Gyeonggi, respectively.

• Journal of Korean Society of Transportation
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• v.27 no.6
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• pp.29-44
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• 2009

A variety of research efforts, using advanced wireless communication technologies, have been made to develop more reliable traffic information system. This study presents a novel decentralized traffic information system based on vehicle infrastructure integration (VII). A major objective of this study was also to devise a methodology for determining appropriate spacing of roadside equipment (RSE) to fully exploit the benefits of the proposed VII-based traffic information system. Evaluation of travel time estimation accuracy was conducted with various RSE spacings and the market penetration rates of equipped vehicle. A microscopic traffic simulator, VISSIM, was used to obtain individual vehicle travel information for the evaluation. In addition, the ANOVA tests were conducted to draw statistically significant results of simulation analyses in determining the RSE spacing. It is expected that the proposed methodology will be a valuable precursor to implementing capability-enhanced next generation traffic information systems under the forthcoming ubiquitous transportation environment.

• Journal of the Economic Geographical Society of Korea
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• v.15 no.1
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• pp.26-41
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• 2012

This study investigates the time-space characteristics of intra-urban passenger flows in the Metropolitan Seoul area. In particular, we analyze the relationships between transit ridership and land use through the use of the subway passenger flow data obtained from the transit transaction databases. For this purpose, the strength of each subway station, i.e., the number of total in-coming and out-going passengers at each station, in the morning, afternoon, and evening, is calculated and visualized, which reflects urban land use patterns. Then the subway stations are classified into four groups via a hierarchical analysis of the in-coming and out-going passenger flows at 353 stations. Each group appears to have characteristic properties according to the region, e.g., residential areas and central business districts. This has been confirmed by the analysis which probes explicitly the relationship between the local socio-economic variables and station groups. This analysis, disclosing the inter-relationship between the subway network and urban land use, may be useful at various stages in urban as well as transportation planning, and provides analytical tools for a wide spectrum of applications ranging from impact evaluation to decision-making and planning support.

• Proceedings of the Korean Society of Computer Information Conference
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• 2013.07a
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• pp.399-400
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• 2013

POP(Point of Production) 시스템은 제조현장에서 발생되는 생산 정보를 실시간으로 수집, 분석하여 현장의 보고 체계를 정형화 시켜준다. 또한 실시간 분석 정보를 통행 생산 이후의 과정(품질관리, 유통, 판매, 생산계획 등)을 기획하고 관리하는데 많은 도움을 준다. 즉, 제조 환경 변화에 따른 생산 지휘 체계를 통제하는 운영 환경을 조성하여 생산성 향상에 크게 기여한다. 이는 특힝 단위 공정의 생산량, 공정의 정확한 측정과 그에 따른 소요시간을 감축하는 장점이 있다. 본 논문에서는 기존의 C/S환경이 아닌 무선인터넷을 이용한 POP시스템을 제시한다.

• Proceedings of the KOR-KST Conference
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• 1998.10a
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• pp.332-341
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• 1998

본 연구는 지역간 고속도로에 비해 통행수요가 높고, 진·출입램프 간격이 짧으며, 구간의 용량변화가 심하고, 기하설계 기준이 낮은 도시고속도로 교통안전시설물의 설치·운영상의 문제점을 검토하고, 이를 통한 개선 방안을 제시하였다. 도시고속도로 교통안전시설물 문헌조사는 국내외 관련 기준서를 비교 분석하였으며, 현황 조사는 서울지역의 도시고속도로중 올림필대로를 중심으로 시설물의 종류, 설치방법, 시인성등을 조사하였다. 문헌과 현황조사 결과에 의하면 현행 시설물 중에는 설치 기준의 누락 또는 새로이 개발된 시설물 기준 등이 미흡하며, 시설물의 설치 및 운영이 현행 기준에 크게 못 미치는 것을 나타났다. 또한 경제성을 고려한 시설상호간 중복 및 모순을 배제할 필요가 있으며, 시설물의 유지관리체계 마련이 시급한 것으로 나타났다. 따라서 본 연구에서는 기초연구를 통한 신개발 시설물의 설치 기준 설정, 현행 기준의 명확한 적용으로 시인성 및 통일성 확보, 시설물의 중복성 배제와 기능성 확립, 유지관리체계 마련, 그리고 도시고속도로 특성에 맞는 시설물 설치 기준서 및 실무지침서의 개발을 제안하였다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.4 no.3 s.8
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• pp.9-22
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• 2005

Route travel cost in transportation networks consists of actual route travel cost and route perception cost. Since the route perception cost is differently perceived according to each origin and each destination, route search has limitation to reflect the note perception cost due to route enumeration problem. Thus, currently employed advanced traveller information systems (ATIS) have considered only actual route travel cost for providing route information. This study proposes an optimal and a K-route searching algorithm which are able to reflect the route perception cost but encompass route enumeration problem. For this purpose, this research defines the minimum nit of route as a link by adopting the link label technique in route searching, therefore the comparison of two adjacent links which can be finally expanded the comparison of two routes. In order to reflect the characteristics of route perception in real situation, an optimal shortest cost path algorithm that both the forward search from the origin and the backward search from the destination can be simultaneously processed is proposed. The proposed algorithm is applied for finding K number of shortest routes with an entire-path-deletion-type of K shortest route algorithm.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.1D
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• pp.23-31
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• 2012

Busan Metropolitan City government has been implementing the local Bus Quasi-Public Operating policy since 2007. As a result of the policy, financial burden to cover financial deficit has become a big social issue. For successful settlement of the policy, the government should be able to gradually cut off the financial support for the deficit by continuously increasing the bus demand, which can be accomplished by providing more convenient bus services. The weather conditions that affect the public transportation demand include rain, fog and snow. They affect the mode choice for public transportation use, which in turn results in decrease in bus demand. In short, the adverse weather conditions result in significant profit loss of bus transportation, and consequently it financially burdens the City of Busan. In this research, the pattern of travelers' use of transportation modes given various weather conditions was analyzed. In addition, the reasons why people transfer from one to other transportation modes were analyzed by conducting a field survey, and policy implications on desirable public transportation facilities and transfer system were discussed.