• Journal of Korean Society of Transportation
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• v.16 no.4
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• pp.167-186
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• 1998

자동차보급의 대중화와 함께 버스, 전철 등 대중교통체계의 지속적인 서비스 확충으로 인해 다양한 교통망의 이용행태가 나타나고 있다. 즉, 승용차를 이용하다가 대중교통수단을 이용하는 경우가 발생하게 되고 이러한 환경에서, 기타 통행대안들(예를 들면 목적지, 수단, 경로 등)이 효율적으로 연계 선택되어질 수 있도록 지원하여 전체 교통체계의 이용효율을 높일 수 있는 방안들이 강구되도록 요구되어지고 있다. 본고는 이런 관점에서 복합교통망에서의 경로안내 체계의 구현을 위한 알고리즘개발과 평가를 주목적으로 한다. 즉, 복합교통망에서의 경로탐색모형과 이 모형에 적용가능한 경로탐색 알고리즘의 제시하고, 이를 위해 복합교통말의 한 축이 되는 대중교통망의 특징을 분석하고 대중교통망에서의 경로탐색알고리즘을 평가하였으며 이를 바탕으로 일반가로망과의 최단경로구축의 통합방안을 제시하였다. 알고리즘의 구현과정을 필요한 데이터의 구축과정과 함께 도시함으로서 모형과 알고리즘에 대한 평가와 함께 실제 구현시 필요한 제반 사항들도 검토하였으며, 장래의 연구과제를 아울러 제시하였다.

• Journal of Korean Society of Transportation
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• v.19 no.2
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• pp.53-60
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• 2001

본 논문의 목적은 대중교통 노선배정 시에 여러 수단간의 환승을 고려함으로써 다수단 대중교통망 내에서 수단선택과 노선선택을 동시에 수행할 수 있도록 확률적인 통행배분(traffic assignment) 모형의 하나인 다이알 알고리즘을 응용할 것을 제시하고 그 알고리즘의 속성을 정확하게 규명하는데 있다 승용차의 확률적 통행배분모형으로 잘 알려져 있는 Dial 알고리즘은 로짓모형에 기초한 것이므로 다수단간의 대중교통 수단선택과 노선선택과 같은 선택 행태를 동시에 설명할 수 있는 모형적 특성을 기본적으로 내재하고 있다. 본 연구에서 제시한 대중교통 노선선택에 적용될 수 있도록 수정된 다이알 알고리즘은 기존의 결정적 대중교 통 노선배정 모형들의 단점을 극복할 수 있는 특성을 갖고 있다. 즉 결정적 대중교통 노선배정모형은 기종점간 최단경로에 교통량을 전랑배분(All-or-Nothing)하여 통행자들의 행태적 속성을 제대로 반영하지 못하고 있으며, 다수단 대중교통망 내에서 환승을 포함한 복합 대중교통수단의 선택을 효용극대화 이론에 기초하지 않고 최소비용노선에 전량배분하는 모형의 한계점을 갖고 있다. 이러한 결정적 대중교통 노선배정모형의 단점을 수정된 다이알 알고리즘은 개선할 수가 있다. 본 연구에서는 알고리즘의 특성을 파악하기 위한 모의실험으로 Sioux Falls 형태의 대중교통 네트워크를 이용하여 기존의 알고리즘과 비교 분석하였다. 분석의 탄력성을 갖고 있는 수정된 대중교통 다이알 알고리즘이 현실적 대중교통 통행패턴을 기존 모형보다 합리적으로 설명할 수 있을 것으로 보이며, 특히 다수단 대중교통망이 형성된 대도시의 대중교통 정책분석에 적합한 기법이 될 수 있을 것으로 고려된다.

• Journal of Korean Society of Transportation
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• v.30 no.4
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• pp.85-94
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• 2012

Modern freight transport pursues not only the reduction of logistic costs but also aims at green logistics and efficient shipments. In order to accomplish these goals, various policies regarding the multimodal shipment and stopover to logistic facilities have widely been made. Such situation requires changes in existing methods for analyzing freight demand. However, the reality is that a reliable freight demand forecast is limited, since in the transport research field there is no robust freight demand model that can accommodate transshipments at logistic facilities. This study suggested a novel method to analyze freight demand, which can consider transshipments in multi-modal networks. Also, the applicability of this method was discussed through an example test.

• Journal of Korean Society of Transportation
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• v.24 no.3 s.89
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• pp.167-176
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• 2006

An minimum path algorithm for integrated networks with departure time constraints require considering arrival time of arriving mode, transfer time. waiting time, and departure time of next mode. Integrated network with diverse modes commonly include departure time constraints. Because public mode suck as train and airplane have fixed service schedule which provide passengers. This study developed the k-path algorithm in integrated network with time varying conditions and departure time constraints. We proposed the extended method based on entire path deletion method, and examined the application of the proposed algorithm through case study.

• Journal of Korean Society of Transportation
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• v.26 no.3
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• pp.233-243
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• 2008

Recognition for the importance and roles of public transportation is increasing because of traffic problems in many cities. In spite of this paradigm change, previous researches related with public transportation trip assignment have limits in some aspects. Especially, in case of multimodal public transportation networks, many characters should be considered such as transfers. operational time schedules, waiting time and travel cost. After metropolitan integrated transfer discount system was carried out, transfer trips are increasing among traffic modes and this takes the variation of users' route choices. Moreover, the advent of high-technology public transportation card called smart card, public transportation users' travel information can be recorded automatically and this gives many researchers new analytical methodology for multimodal public transportation networks. In this paper, it is suggested that the methodology for establishment of brand new multimodal public transportation networks based on computer programming methods using transportation card data. First, we propose the building method of integrated transportation networks based on bus and urban railroad stations in order to make full use of travel information from transportation card data. Second, it is offered how to connect the broken transfer links by computer-based programming techniques. This is very helpful to solve the transfer problems that existing transportation networks have. Lastly, we give the methodology for users' paths finding and network establishment among multi-modes in multimodal public transportation networks. By using proposed methodology in this research, it becomes easy to build multimodal public transportation networks with existing bus and urban railroad station coordinates. Also, without extra works including transfer links connection, it is possible to make large-scaled multimodal public transportation networks. In the end, this study can contribute to solve users' paths finding problem among multi-modes which is regarded as an unsolved issue in existing transportation networks.

• Journal of Korean Society of Transportation
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• v.24 no.5 s.91
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• pp.77-88
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• 2006

The purpose of this study is to Propose the time dependent K-least time path algorithm applicable to a real-time based operation strategy in multi-modal transportation network. For this purpose, we developed the extended method based on entire path deletion method which was used in the static K-least time path algorithm. This method was applied to time dependent K-least time path algorithm to find k least time paths in order based on both time dependant mode-link travel time and transfer cost In particular, this algorithm find the optimal solution, easily describing transfer behavior, such as walking and waiting for transfer by applying a link-based time dependent label. Finally, we examined the verification and application of the Proposed algorithm through case study.

• Journal of Korean Society of Transportation
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• v.26 no.1
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• pp.127-135
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• 2008

Generally, optimum shortest path algorithms adopt single attribute objective among several attributes such as travel time, travel cost, travel fare and travel distance. On the other hand, multi-objective shortest path algorithms find the shortest paths in consideration with multi-objectives. Up to recently, the most of all researches about multi-objective shortest paths are proceeded only in single transportation mode networks. Although, there are some papers about multi-objective shortest paths with multi-modal transportation networks, they did not consider transfer problems in the optimal solution level. In particular, dynamic programming method was not dealt in multi-objective shortest path problems in multi-modal transportation networks. In this study, we propose a multi-objective shortest path algorithm including dynamic programming in order to find optimal solution in multi-modal transportation networks. That algorithm is based on two-objective node-based label correcting algorithm proposed by Skriver and Andersen in 2000 and transfer can be reflected without network expansion in this paper. In addition, we use non-dominated paths and tree sets as labels in order to improve effectiveness of searching non-dominated paths. We also classifies path finding attributes into transfer and link travel attribute in limited transit networks. Lastly, the calculation process of proposed algorithm is checked by computer programming in a small-scaled multi-modal transportation network.

• Journal of Korean Society of Transportation
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• v.23 no.8 s.86
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• pp.7-17
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• 2005

Transportation is from an individual mobility. Various efforts to propose specific values or the individual mobility have been conducted in diverse transportation environment. However, mobility studies for multimodal public transportation are rare especially on not the range of line but area. This study propose a method to calculate transit mobility indices as expanding mobility analysis from point-to-point to area-to-area, considering access time to transit facility, running time and transfer time of passengers. To extract mobility indices, we included walking as a lowest category of mode and set passenger car as a competitive mode to transit mode. This study propose three public transportation mobility indices as 1) how competitive public transportation facility is offered against passenger car 2) how convenient transit mode including walking is provided against passenger car from origin to destination and 3) how many various paths are presented to support passenger's travel between regions. These indices are tested on the Seoul metropolitan area with 10 lines of urban rail and about 420 lines of bus. In addition, we proposed two political applications of proposed mobility indices to increase public transportation mobility between two regions and to maximize the mobility of study area when a line is added in the area.

• Journal of Korean Society of Transportation
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• v.3 no.1
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• pp.94-104
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• 1985

도시부의 활동이 지방부의 그것과 크게 다른점은 토지이용의 집약도가 높은 데 있 다 하겠다. 지금까지 도시부 토지이용의 밀도변위등에 관계되는 사정은 잘 인식되어 오기는 하였으나 이를 실용적 모형으로 다룬 예는 극히 드물다. 본 논문은 다양한 수송수단을 포용 하는 교통망에서의 혼잡비용이 토지이용의 집약도에 따라 효과적으로 결정될 수 있도록 하 는 토지이용과 교통의 복합모형을 제시하였다. 이를 위하여 다품종교통류 및 I/O모형의 범 주에서 비선형계획의 접근방법이 채택되었다.

• Journal of Korean Society of Transportation
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• v.23 no.1
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• pp.103-114
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• 2005

The transit fare resulted from the renovation of public transit system in Seoul is basically determined based on the distance-based fare policy (DFP). In DFP, the total fare a passenger has to pay for is calculated by the basic-transfer-premium fare decision rule. The fixed amount of the basic fare is first imposed when a passenger get on a mode and it lasts within the basic travel distance. The transfer fare is additionally imposed when a passenger switches from one mode to another and the fare of the latter mode is higher than the former. The premium fare is also another and the fare of the latter begins to exceed the basic travel distance and increases at the proportion of the premium fare distance. The purpose of this study is to propose an algorithm for finding K number of paths, paths that are sequentially sorted based on total amount of transit fare, under DFP of the idstance-based fare policy. For this purpose, the link mode expansion technique is proposed in order to save notations associated with the travel modes. Thus the existing K shortest path algorithms adaptable for uni-modal network analysis are applicable to the analysis for inter-modal transportation networks. An optimality condition for finding the K shortest fare routes is derived and a corresponding algorithms is developed. The case studies demonstrate that the proposed algorithm may play an important role to provide diverse public transit information considering fare, travel distance, travel time, and number of transfer.