• Proceedings of the KIPE Conference
• /
• 2007.07a
• /
• pp.217-219
• /
• 2007

본 논문에서는 열차의 실제 노선 운행을 모의하여 구동 장치의 특성을 평가하고 에너지 절약에 대한 연구를 하였다. 이에 대하여 열차의 구동 에너지를 절약하기 위한 모터의 제어 방식과 제너레이터의 회생 에너지에 관한 연구를 선택하였다. 실제 대전 지하철의 노선 데이터를 이용하여 열차 주행 결과를 시뮬레이션 하였다. SVM (Space Vector Modulation) - DTC (Direct Torque Control)로 구현된 M-G Set으로 열차가 주행 시 모터에서 소비되는 에너지와 제동 시 제너레이터에서 발생되는 회생 에너지를 Simplorer 프로그램을 이용하여 시뮬레이션 하였다. 시뮬레이션 결과를 통해 열차의 소비 에너지와 회생 에너지를 연구한다.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.39 no.6
• /
• pp.853-858
• /
• 2019

One of the methods which can enhance the efficiency of railroad network is construction of interconnection branch line for several route to share one railway. In Korea, this method already has been implemented or excuted as project level. This study suggests a network design model and a solution algorithm to choice most proper site to construction it and determine the priority of branch lines which can be considered in planning level, not project level. The model is a non-linear optimization program which minimize total cost-construction cost, operating cost and passengers' travel cost. The decision variables are a binary variable to explain whether construction or not and its direction and a integer variable of the frequencies of travel routes. The solution algorithm-problem solution and route choice and also the result of implementation for example network are suggested. This result can be more advanced after application in real network and calibration of parameters.

• Spatial Information Research
• /
• v.11 no.3
• /
• pp.275-289
• /
• 2003

This study focused on offering a helpful information for the touring. To develop a tour route guidance tool, it is needed to use a GIS function, which can suggest a possible shortest path based on time and distance. A Traveling salesman problem algorithm, which was developed to solve multi destination problem in network analysis, was used to implement a tour guidance system. This system was developed using ArcObjects programming components within ArcGIS 8.3. Jeju city was selected for the case study to apply the tool and to test the effectiveness of it. This study demonstrated that this tool was considerably effective for finding a probable optimum tour path in the following aspects. First, it can help tourists to select several attractions from numerous tour sites in an area given limited time. Second, tourist can manage time efficiently by organizing their tour courses on the basis of the tool. Third, tourists can reduce the uncertainties that may happen under unexpected situations in unfamiliar places by obtaining specific spatial information using the tool. Fourth, the Graphic User Interface of the tool can be easily used to obtain visual information of spatial data.

• Journal of the Korean Geographical Society
• /
• v.38 no.4
• /
• pp.478-489
• /
• 2003

The existing researches related to the fog have focused on mainly the fog itself and its spatial variation. This study defined the hazardous fog as the fog with visibility under 500 m which caused the severe dangerous situation on roads and might cause traffic accident due to insufficient visibility. This study aimed to develop the hazardous fog index which quantified the degree of danger and included frequency of fog, visibility and its duration. We applied the index to 3 years weather station data in Korea and the results showed the distribution of the hazardous fog and their priority in terms of safety management. This was the first study that introduced the fog index in Korea and that quantified the degree of hazardous fog. These application results were useful for identifying the dangerous area due to hazardous fog and contributing to ensure the safety of eventual road users and road authorities.

• Journal of Korean Society of Transportation
• /
• v.27 no.6
• /
• pp.147-156
• /
• 2009

We present a methodology for modeling and solving the transit frequency design problem with variable demand. The problem is described as a bi-level model based on a non-cooperative Stackelberg game. The upper-level operator problem is formulated as a non-linear optimization model to minimize net cost, which includes operating cost, travel cost and revenue, with fleet size and frequency constraints. The lower-level user problem is formulated as a capacity-constrained stochastic user equilibrium assignment model with variable demand, considering transfer delay between transit lines. An efficient algorithm is also presented for solving the proposed model. The upper-level model is solved by a gradient projection method, and the lower-level model is solved by an existing iterative balancing method. An application of the proposed model and algorithm is presented using a small test network. The results of this application show that the proposed algorithm converges well to an optimal point. The methodology of this study is expected to contribute to form a theoretical basis for diagnosing the problems of current transit systems and for improving its operational efficiency to increase the demand as well as the level of service.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.34 no.5
• /
• pp.1525-1534
• /
• 2014

In recent years, the passengers are likely to decide their route on impulse due to the development of the integrated public transport system, and real-time information system. Especially, public transport fare integration in Seoul Metropolitan area, 2004 makes them not to have resistance about changing the modes or routes and their route choice is most effected by the degree of congestion. Assignment model have limitations to describe route changes by congestion. In this study, the concept of a link cost function used in road assignment and Effective frequency is introduced to describe the passengers' behavior when the capacity of public transport is over and the waiting time variation. Two situations, new transit line operation and accident, are set up to validate the model, as a result of the transit assignment by this model, the traffic on networks is not over the capacity. It is expected that this study will be of help to reflect the various behaviors in transit assignments.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.21 no.5
• /
• pp.1-14
• /
• 2022

In this study, in order to analyze the preference for UAM of public transportation users following the introduction of urban air transportation(UAM), A preference consciousness(SP) survey was conducted on 840 users of Incheon public transportation using the Incheon International Airport-Incheon Gil Hospital route, which is the urban air traffic(UAM) demonstration route section. In addition, the means selection model was estimated based on the results of conducting a preference consciousness (SP) survey. As a result of analyzing the time value for travel using the established means selection model, it was found to be 56,428 won/hour, As a result of verifying the elasticity of travel cost (won), in-vehicle time (minutes), and out-of-vehicle time (minutes) in the model, the effect on the urban air traffic (UAM) share in this model was found that travel cost (won), in-vehicle time (minutes), and out-of-vehicle time (minutes) were in order, and the effect was greater when the travel cost (won) decreased than when it increased.

• Spatial Information Research
• /
• v.22 no.5
• /
• pp.65-75
• /
• 2014

Bus headway plays an important role not only in determining the passenger waiting time and bus service quality, but also in influencing the bus operation cost and passenger demand. Previous research on headway control has considered only an hourly difference in the distribution of ridership between peak and non-peak hours. However, this approach is too simple to help manage ridership demand fluctuations in a short time scale; thus passengers' waiting cost will be generated when ridership demand exceeds the supply of bus services. Moreover, bus ridership demand varies by station location and traffic situation. To address this concern, we propose a headway control algorithm for minimizing the waiting time cost by using Smart Card data. We also provide proof of the convergence of the algorithm to the desired headway allocation using a set of preconditions of political waiting time guarantees and available fleet constraints. For model verification, the data from the No. 143 bus line in Seoul were used. The results show that the total savings in cost totaled approximately 600,000 won per day when we apply the time-value cost of waiting time. Thus, we can expect that cost savings will be more pronounced when the algorithm is applied to larger systems.

• Journal of Korean Society of Transportation
• /
• v.28 no.1
• /
• pp.15-24
• /
• 2010

Until now, the location and the size of gate are designed by only experience and intuitive use judgement. However there are no studies that investigated how many people will be using each subway gate depending on the location of gates. Therefore, the purpose of this study is to develop a gate choice model of subway station. The most critical element of a gate choice in subway station is the location of pedestrian's destinations. In this study, the development of the regression model is constructed from data of land use characteristic of station vicinity and the number of bus route and the space structure of station vicinity(Depth concept by Space Syntax analysis and total road length of station vicinity) by using the real data of 30 subway station in Seoul. This study found that subway pedestrian flow are mainly determined by three factors; the total floor space of commercial buildings, Total Depth(space structure index of station vicinity), and the number of bus route. The verification of a proposed model is done by using the real gate pedestrian data of two subway station in Seoul; Gang-nam and Yang-jae. The additional study of how to define the gate impact area is analysed. Therefore, this study will provide the theoretical bases in decision of gate location and size when a new subway station is opened in future.

• Journal of Korean Society of Transportation
• /
• v.25 no.2 s.95
• /
• pp.133-143
• /
• 2007

Previous studies on the transit assignment hardly show its achievement in research but have many limitations not only in theory but also in practice. This paper presents an integrated transit assignment model taking into account cost functions of multiple modes, such as auto, bus and subway, which represent an integrated network. An integrated transit network including cost functions and in-vehicle congestion needs to be developed. In addition, a link fare calculation model needs to be developed and applied to the model to calculate path travel costs. Based on these sub-models, a path-based traffic assignment model, which considers in-vehicle congestion and an integrated distance-based fare system in the integrated traffic network, is developed.