• Title/Summary/Keyword: Shortest Path Algorithm

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A Genetic Algorithm for Route Guidance System in Intermodal Transportation Networks with Time - Schedule Constraints (서비스시간 제한이 있는 복합교통망에서의 경로안내 시스템을 위한 유전자 알고리듬)

  • Chang, In-Seong
    • 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.

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Male-Silkmoth-Inspired Routing Algorithm for Large-Scale Wireless Mesh Networks

  • Nugroho, Dwi Agung;Prasetiadi, Agi;Kim, Dong-Seong
    • Journal of Communications and Networks
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    • v.17 no.4
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    • pp.384-393
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    • 2015
  • This paper proposes an insect behavior-inspired routing algorithm for large-scale wireless mesh networks. The proposed algorithm is adapted from the behavior of an insect called Bombyx mori, a male silkmoth. Its unique behavior is its flying technique to find the source of pheromones. The algorithm consists of two steps: the shortest-path algorithm and the zigzag-path algorithm. First, the shortest-path algorithm is employed to transmit data. After half of the total hops, the zigzag-path algorithm, which is based on the movement of the male B. mori, is applied. In order to adapt the biological behavior to large-scale wireless mesh networks, we use a mesh topology for implementing the algorithm. Simulation results show that the total energy used and the decision time for routing of the proposed algorithm are improved under certain conditions.

A Kth Shortest Path Algorithm with the Link-Based Label Setting Approach and Its Application for An Alternative Routes Selection (링크표지확정 다수경로탐색 알고리즘과 대안경로선정을 위한 활용)

  • Lee, Mee-Young;Baik, Nam-Cheol;Kang, Weon-Eui;Shin, Seong-Il
    • 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.

A Fast Shortest Path Algorithm Between Two Points inside a Segment-Visible Polygon (선분가시 다각형 내부에 있는 두 점 사이의 최단 경로를 구하는 빠른 알고리즘)

  • Kim, Soo-Hwan
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.2
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    • pp.369-374
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    • 2010
  • The shortest path between two points inside a simple polygon P is a minimum-length path among all paths connecting them which don't pass by the exterior of P. A linear time algorithm for computing the shortest path in a general simple polygon requires triangulating a polygon as preprocessing. The linear time triangulating is known to very complex to understand and implement it. It is also inefficient in case that the input without very large size is given because its time complexity has a big constant factor. In this paper, we present the customized shortest path algorithm for a segment-visible polygon which is a simple polygon weakly visible from an internal line segment. Our algorithm doesn't require triangulating as preprocessing and consists of simple procedures such as construction of convex hulls, so it is easy to implement and runs very fast in linear time.

Path Planning Based on Spline D* for Mobile-robot (이동로봇을 위한 스플라인 D* 기반의 경로 계획)

  • Ryu, Hee-Rack;Choi, Yun-Won;Saitov-Sinl, Dilshat;Lee, Suk-Gyu
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.1
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    • pp.92-98
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    • 2014
  • This paper proposes a hermite spline based D* algorithm for effective path planning of mobile robot to improve the detecting speed. In conventional path planning research, a robot is supposed to pass through predetermined centers of grid partitions of area. However it doesn't guarantee the optimal path during its navigation. In addition, a robot is hard to avoid obstacles effectively. The proposed algorithm in this paper makes use of stochastic characteristics of nonholonomic mobile robot and estimation of shortest path to curvature movement of the robot. The performance evaluation of the improved spline D* algorithm performed through simulation shows its effectiveness. Moreover, the experiment verifies that a robot can find the shortest path by building the curve paths while it is moving on the path in spline.

A Polynomial-time Algorithm for Choosing the Shortest Transportation Path of Logistic Material (최적 보급수송로 선정을 위한 다항시간 알고리듬)

  • 서성철;정규련
    • Journal of the military operations research society of Korea
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    • v.23 no.2
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    • pp.103-119
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    • 1997
  • This paper considers the shortest path problem combined with Min-Min-Sum objective for solving the problem of the military logistics. This paper develops a polynomial-time algorithm for the optimal solution. To analyze the real combat situation, the ability time and distance time of communication line are considered. The complexities of algorithm between previous study and the algorithm developed in this paper is presented. Finally we provide a simple example of application with randomly generated problem.

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Finding Rectilinear(L1), Link Metric, and Combined Shortest Paths with an Intelligent Search Method (지능형 최단 경로, 최소 꺾임 경로 및 혼합형 최단 경로 찾기)

  • Im, Jun-Sik
    • The Transactions of the Korea Information Processing Society
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    • v.3 no.1
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    • pp.43-54
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    • 1996
  • This paper presents new heuristic search algorithms for searching rectilinear r(L1), link metric, and combined shortest paths in the presence of orthogonal obstacles. The GMD(GuidedMinimum Detour) algorithm combines the best features of maze-running algorithms and line-search algorithms. The SGMD(Line-by-Line GuidedMinimum Detour)algorithm is a modiffication of the GMD algorithm that improves efficiency using line-by-line extensions. Our GMD and LGMD algorithms always find a rectilinear shortest path using the guided A search method without constructing a connection graph that contains a shortest path. The GMD and the LGMD algorithms can be implemented in O(m+eloge+NlogN) and O(eloge+NlogN) time, respectively, and O(e+N) space, where m is the total number of searched nodes, is the number of boundary sides of obstacles, and N is the total number of searched line segment. Based on the LGMD algorithm, we consider not only the problems of finding a link metric shortest path in terms of the number of bends, but also the combined L1 metric and Link Metric shortest path in terms of the length and the number of bands.

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Shortest Dubins Path Generation Algorithm for a Car-like Robot (자동차형 로봇의 전방향 최단거리 이동경로 생성을 위한 알고리즘)

  • Cho, Gyu-Sang
    • Proceedings of the KIEE Conference
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    • 2003.07d
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    • pp.2423-2425
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    • 2003
  • This paper proposes a decision criteria for selecting the shortest path from Dubins set between the initial and final configurations of a car-like robot. The suggested scheme is a very simple and computational savings without explicitly calculating the candidate paths and having a complicated decision table. Equations for calculating the shortest path are derived in simple form with coordinate transform and defining standard forms.

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Collision-Avoidance and Optimal Path Planning of Autonomous Mobile Robot using Soft-Computing (소프트 컴퓨팅에 의한 자율 이동로봇의 충돌 회피 및 최적 경로계획)

  • Ha, Sang-Hyung;Choe, In-Chan;Kim, Hyeon-Seong;Jeon, Hong-Tae
    • Journal of the Korean Institute of Intelligent Systems
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    • v.20 no.2
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    • pp.195-201
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    • 2010
  • Recently, the necessity of the autonomous mobile robot is emphasized in order to enlarge the scope of activity and actively cope with the change of work environment. This paper proposes the algorithm which enables the mobile robot to avoid obstacles and lead it to the destination by the shortest path. And we verify the usability by a simulation. We made the algorithm with micro-GA and $\lambda$-geometry MRA. The area of simulation is limited to 320(width)$\times$200(length) pixels and one pixel is one centimeter. When we planned the path with only $\lambda$-geometry MRA, we could find the direction for path planning but could not find the shortest path. But when we planned the path with $\lambda$-geometry MRA and micro-GA, we could find the shortest path. So the algorithm enables us to find the direction for path planning and the shortest path.

Minimum Travel Time Paths for ATIS in Urban Road Networks Using Genetic Algorithms (유전자 알고리즘을 이용한 도시도로망에서의 첨단 여행자 정보시스템(ATIS) 운영계획)

  • 장인성;문형수
    • Journal of Korean Society of Transportation
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    • v.19 no.4
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    • pp.85-96
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    • 2001
  • This paper discusses the problem of finding the Origin-Destination(O-D) shortest path in urban road networks that have variable special qualifies such as time windows for passing as well as geometrical special qualities such as U-turn and left-turn prohibition. The focus of this paper is motivated by the problem of finding minimum travel time paths for an advanced traveler information system (ATIS) in the context of intelligent transportation system(ITS) application. The transportation network with variable and geometrical special qualities is a more realistic representation of the urban road network in the real word. But, the traditional and existing shortest path algorithms can not search practical shortest path that variable special quality is reflected. This paper presents a shortest path algorithm which can search reasonable shortest path information for the urban ATIS application within a real time. The algorithm is based on genetic algorithm(GA). The high performance of the proposed algorithm is demonstrated by computer simulations.

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