• The Transactions of the Korea Information Processing Society
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• v.3 no.6
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• pp.1483-1492
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• 1996

In this paper, related on the postal business with the GIS(Geographics Information System), it discusses design and implementation of the PROS(Postal Route Optimization System) model and its main module, the shortest path generation algorithm, for supporting to postal route managements. It explains examples requirements of postal route system, and suggests the efficient PROS model using our developed shortest path generation algorithm. Because the shortest path algorithm adopts not only consider the Dijkstra algorithm of graph theory, but also the method with the direction property, PROS can be implemented with fast and efficient route search. PROS is mainly constituted of the Shortest Generator, the Isochronal Area Generator, and the Path Rearrangement Generator. It also exploits the GIS engine and the spatial DBMS (Data Base Management System) for processing coordinates in the map and geographical features. PROS can be used in the management of postal delivery business and delivery area and route, and in the rearrangement of route. In the near future, it can be also applied to commercial delivery businesses, guides of routs and traffic informations, and auto navigation system with GPS(Global Positioning System).

• 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.

• The Transactions of the Korea Information Processing Society
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• v.4 no.2
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• pp.491-498
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• 1997

Geographic Infprmation System(GIS)is being apply to extended from specified ppkication to general purpose deu to the omprovement of computing power.As one part of postal Integarated Information Servies, Postalroute Optimication system(PROS) is comprsed of the composed of the shortest pathe genrator for providing fast and shortest route of postal delivery, the ischronal area generator, the boudary relacation generator, GIS engine, road map, and rdelational database , etc.This paper is related to creation algorithm of the shortest path generation (SPAWD;Shortest Path Algorithm With Direction)from PEOS model.To differ from the exsting shortest path generating methods, this paper suggests SPAWD alforithm for searching destinations of fast time between start and destination points with dirdstion.It comapares and analyzes the new algorithm with existion algorithms, and suggests directions of future studies.

• Korean Management Science Review
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• v.18 no.1
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• pp.105-118
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• 2001

The common shortest path problem is to find the shortest route between two specified nodes in a transportation network with only one traffic mode. The public transportation network with multiple traffic mode is a more realistic representation of the transportation system in the real world, but it is difficult for the conventional shortest path algorithms to deal with. The genetic algorithm (GA) is applied to solve this problem. The objective function is to minimize the sum of total service time and total transfer time. The individual description, the coding rule and the genetic operators are proposed for this problem.

• Journal of Digital Contents Society
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• v.13 no.3
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• pp.451-457
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• 2012

Recently, as the use of real time traffic information of a car navigation system increases rapidly with the development of Intelligent Transportation Systems (ITS), path search is getting more important. Previous algorithms, however, are mostly for the shortest distance searching and provide route information using static distance and time information. Thus they could not provide the most optimal route at the moment which changes dynamically according to traffic. Accordingly, in this study, Semantic Shortest Path algorithm with Reduction ratio & Distance(SSP_RD) is proposed to solve this problem. Additionally, a routing model based on velocity reduction ratio and distance and a dynamic route link map are proposed.

• Journal of applied mathematics & informatics
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• v.17 no.1_2_3
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• pp.1-23
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• 2005

The shortest-paths problem is a fundamental problem in graph theory and finds diverse applications in various fields. This is why shortest path algorithms have been designed more thoroughly than any other algorithm in graph theory. A large number of optimization problems are mathematically equivalent to the problem of finding shortest paths in a graph. The shortest-path between a pair of vertices is defined as the path with shortest length between the pair of vertices. The shortest path from one vertex to another often gives the best way to route a message between the vertices. This paper presents an $O(n^2)$ time sequential algorithm and an $O(n^2/p+logn)$ time parallel algorithm on EREW PRAM model for solving all pairs shortest paths problem on circular-arc graphs, where p and n represent respectively the number of processors and the number of vertices of the circular-arc graph.

• Journal of Korean Society of Transportation
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• v.22 no.4 s.75
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• pp.85-96
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• 2004

Given a Path represented by a sequence of link numbers in a transportation network, the reasonable path is defined as a path that any link is appeared multiple times in it. Application of the link labelmethod(LLM) to the shortest path algorithms(SPA) enables to model the reasonable path choice behavior in urban networks. This study aims at expanding the LLM to a Kth shortest path algorithms(KPSA), which adopts the node label setting method. The small-scaled network test demonstrated that the proposed algorithm works correctly and the revised Sioux fall network test showed that the path choice behaviors are reasonably reflected. In the large-scaled network based on the South Korea peninsula, drivers' route diversion perceptions are included as cost terms in total cost. The algorithm may be applied as an alternative route information tools for the deployment of ATIS.

• Journal of Korean Institute of Industrial Engineers
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• v.27 no.2
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• pp.140-149
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• 2001

The paper discusses the problem of finding the Origin-Destination(O-D) shortest paths in internodal transportation networks with time-schedule constraints. The shortest path problem on the internodal transportation network is concerned with finding a path with minimum distance, time, or cost from an origin to a destination using all possible transportation modalities. The time-schedule constraint requires that the departure time to travel from a transfer station to another node takes place only at one of pre-specified departure times. The scheduled departure times at the transfer station are the times when the passengers are allowed to leave the station to another node using the relative transportation modality. Therefore, the total time of a path in an internodal transportation network subject to time-schedule constraints includes traveling time and transfer waiting time. In this paper, a genetic algorithm (GA) approach is developed to deal with this problem. The effectiveness of the GA approach is evaluated using several test problems.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.219-221
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• 2022

In recent summer, as it is concentrated, even in mountainous areas, flooding and flooding cause casualties in pedestrian evacuation situations. To compensate for this, a system that detects the occurrence of flooding and allows pedestrians to evacuate safely is required. Therefore, in this paper, we propose a research on pedestrian path search based on the shortest distance algorithm using Map API. The pedestrian route search system outputs a map using the T Map API, selects nearby buildings as shelters, and stores data. A shelter close to the pedestrian's current location is selected, and the shortest route is output and the distance and time are provided. If there is a problem with the current route during evacuation, another shelter route is provided from the current location. Therefore, it is thought that the pedestrian route search evacuation system proposed in this paper will prevent accidents during evacuation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.415-418
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• 2018

To reduce the flooding overhead of typical AODV, we propose a local flooding initiated by a destination. The proposed routing protocol determines the one-hop neighbor nodes around the shortest path between source and destination by overhearing, and periodically generate flooding at the destination to cope with topology changes. This flooding process involves only one-hop neighbor nodes around the shortest path for reducing the flooding overhead and forms multiple alternate paths around the shortest path. This makes it possible to seamlessly route to the newest shortest path around when the current routing path is disconnected.