• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.6
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• pp.14-25
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• 2020

This research proposes a methodology to evaluate the rationality of passengers' route choice who make trips within Seoul metropolitan subway based on smart card data. The rationality of user route choice is divided into the degree of determinacy and similarity concepts as basic principle. Determinacy is the degree to which the route selected by the passenger is identical to the system optimal path. Similarity indicates the degree to which the route is similar to the system optimal path. The K-path search method is used for path enumeration, which allows for measurement of determinacy. To assess determinacy within similarity, transfer tag data of private operators is used. Consequently, the concept of similarity applied to the model is such that the passenger's path choice is identical to the path taken using the tag reader. Results show that the determinacy of appearance of the shortest path (K=1) is 90.4%, while the similarity of appearance as K=(2-10) is 7.9%, summing to 98.3%. This indicates that trips on the metropolitan subway network are being rationally explained. 1.7% of irrational trips are attributed to the unexplainable error term that occurs due to the diversity of passengers.

• The Transactions of the Korea Information Processing Society
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• v.7 no.10
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• pp.3164-3170
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• 2000

The use of the A' for the path search of the agent in the game map give the overhead of computing time in real time game processing. The other heuristic search algorithms do not guarantee the optical path. The route table of which the row is defined by current position, goal position, visiting position is presented in this paper. This route table is made in the game development phase and tilized in game playing. The visiting position which is contatined in the optimal path to the goal position from the current position can guarantee the optical path, and this mothod has no overhead on computing time. But the memory space is requred too much. This problem can also be solved using the data compression by skipping the duplicated route table.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.10a
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• pp.39-41
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• 2014

최근 유가인상, 운임하락, 온실가스규제 등의 복합적인 요인으로 선박의 운항 효율 관리를 위한 직 간접적인 방법이 개발되고 있으며, 실제로 이를 지원하는 시스템의 탑재사례가 늘고 있다. 본 논문에서는 이러한 경제운항지원시스템들 중에서 실시간 기상정보와 그에 기초한 선박의 부가저항을 고려한 최적의 추천경로를 제공하는 최적 항로 지원 시스템에 대해 기술하고자 한다. 본 시스템은 주어진 ETA (Estimated Time of Arrival) 범위 내에서, 기상예보를 바탕으로 연비관점에서의 최적의 경로 및 엔진출력을 제안하며, 추천경로 및 실제운항경로 사이의 효율비교와 함께 항해정보분석까지 가능한 것을 특징으로 한다. 이러한 시스템은 선박의 연료절감과 함께 운항경로 전반에 대한 포괄적인 이해에 도움을 줄 것으로 기대한다.

• Proceedings of the Korea Multimedia Society Conference
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• 2004.05a
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• pp.322-325
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• 2004

인터넷 통신과 무선 이동 통신의 발달은 최적 경로 탐색이 인터넷 웹 페이지를 통하여 서비스될 수 있도록 하였으며, CNS(Car Navigation System)를 이용한 서비스도 가능하도록 하였다. 더욱이 개인용 휴대통신 장비인 PDA나 휴대폰을 이용하여서도 그 서비스가 제공되고 있지만, 휴대폰에서의 최적 경로 표현은 화면 크기의 제약성 때문에 많은 정보를 나타내기 어려우며, 휴대폰의 환경에 맞도록 기존의 공간 DB를 수정하는 것 또한 많은 비용과 시간이 필요하다. 이에 본 논문에서는 기존의 DB를 이용하면서 사용자가 입력한 출발지와 목적지 정보를 이용하여 최적 경로 탐색을 수행하고, 탐색된 최적 경로를 일반화 알고리즘을 이용하여 휴대폰의 작은 화면에서 사용자가 쉽게 인지할 수 있도록 약도화 하는 알고리즘을 제안한다.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.6
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• pp.823-829
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• 2012

Data communications networks at sea in the future can be modelled by overlapped MANET networks with Broadband Wireless Access carriers. A novel routing scheme (CPLR) is proposed in this paper, which finds out an optimal route by selecting an optimal carrier for each hop in routes based on carrier preferences of each application, and locations of ships as well. As distances between each ships and destination ships are considered in this scheme, routing can be done much faster. Performance is compared with that of the CPR (only Carrier Preference-based Routing Scheme), and it shows some improvements.

• Journal of Korean Society of Transportation
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• v.26 no.1
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• pp.145-153
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• 2008

Existing shortest-path algorithms mainly consider a single attribute. But traveler actually chooses a route considering not single attribute but various attributes which are synthesized travel time, route length, personal preference, etc. Therefore, to search the optimal path, these attributes are considered synthetically. In this study route searching algorithm which selects the maximum utility route using discrete choice model has developed in order to consider various attributes. Six elements which affect route choice are chosen for the route choice model and parameters of the models are estimated using survey data. A multinomial logit models are developed to design the function of route choice model. As a result, the model which has route length, delay time, the number of turning as parameter is selected based on the significance test. We use existing shortest path algorithm, which can reflect urban transportation network such as u-turn or p-turn, and apply it to the real network.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.206-209
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• 2005

Optimal path search systems to take continuously changed traffic flows into consideration is necessary in order to reduce the cost to get destination. However, to search optimal path in client terminals with low computing power yields high computational cost. Thus, a method with low cost and near optimal path as well is required. In this paper, we propose a path search method using variable heuristic for the sake of reducing operation time. The heuristic is determined by the change of the average speeds of cars located in grid which means a rectangle region.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.6
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• pp.687-693
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• 2012

In this paper, we propose a optimal deployment method for cooperative exploration of swarm robots. The proposed method consists of two parts such as optimal deployment and path planning. The optimal area deployment is proposed by the K-mean Algorithm and Voronoi tessellation. The path planning is proposed by the potential field method and A* Algorithm. Finally, the numerical experiments demonstrate the effectiveness and feasibility of the proposed method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.12
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• pp.2221-2229
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• 2006

Optimal path search algorithm which is a killer application of mobile device to utilize location information should consider traffic flows of the roads as well as the distance between a departure and destination. The existing path search algorithms, however, are net able to cope efficiently with the change of the traffic flows. In this paper, we propose a new optimal path search algorithm. The algorithm takes the current flows into consideration in order to reduce the cost to get destination. It decomposes the road network into Fixed Grid to get variable heuristics. We also carry out the experiments with Dijkstra and Ar algorithm in terms of the execution time, the number of node accesses and the accuracy of path. The results obtained from the experimental tests show the proposed algorithm outperforms the others. The algorithm is highly expected to be useful in a advanced telematics systems.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.9
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• pp.1931-1938
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• 2012

A by-pass path in wireless sensor networks is the alternative path which be able to forward data when a routing path is being broken. One reason of depleting energy is occurred by the path. The method for solving prior to addressed the problem is proposed. However, this method may deplete radio resource. The best path has advantage that network lifetime of sensor nodes is prolonged; on the contrary, in order to maintain the best path it have to share their information between the entire nodes. In this paper, we propose the best path searching algorithm in the distributed three dimensional sensor networks. Through the neighboring informations sharing in the proposed method, the proposed algorithm can decide the best k-path as well as the extension of network lifetime.