• Title/Summary/Keyword: Path optimization

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Loop Cancellation and Path Optimization of Path Extension Handover in a Wireless ATM LAN (무선 ATM LAN 환경에서 경로 확장 기법의 루프 제거 및 경로 최적화 알고리즘 연구)

  • 최우진;박영근
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.5A
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    • pp.602-610
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    • 2000
  • There has been increasing interest in broadband services to mobile terminals. Wireless ATM will be used to support broadband services for future generation mobile service. We propose an algorithm for handover in wireless ATM LANs. We have studied how to treat the loop cancellation and optimization of path extension handover scheme, and present path optimization algorithms : polyangular loop cancellation and triangular loop cancellation. We express the location of MT(mobile terminal) by direction angle, and the direction angles can be converted into direction vectors. Using direction vectors, we can find the current optimal path of MT. The analysis and the experimental results show that the proposed scheme provides the better performance than that of anchor rerouting scheme in average handover delay, handover disruption delay, and buffer requirements.

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Recurrent Ant Colony Optimization for Optimal Path Convergence in Mobile Ad Hoc Networks

  • Karmel, A;Jayakumar, C
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.9
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    • pp.3496-3514
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    • 2015
  • One of the challenging tasks in Mobile Ad hoc Network is to discover precise optimal routing solution due to the infrastructure-less dynamic behavior of wireless mobile nodes. Ant Colony Optimization, a swarm Intelligence technique, inspired by the foraging behaviour of ants in colonies was used in the past research works to compute the optimal path. In this paper, we propose a Recurrent Ant Colony Optimization (RECACO) that executes the actual Ant Colony Optimization iteratively based on recurrent value in order to obtain an optimal path convergence. Each iteration involves three steps: Pheromone tracking, Pheromone renewal and Node selection based on the residual energy in the mobile nodes. The novelty of our approach is the inclusion of new pheromone updating strategy in both online step-by-step pheromone renewal mode and online delayed pheromone renewal mode with the use of newly proposed metric named ELD (Energy Load Delay) based on energy, Load balancing and end-to-end delay metrics to measure the performance. RECACO is implemented using network simulator NS2.34. The implementation results show that the proposed algorithm outperforms the existing algorithms like AODV, ACO, LBE-ARAMA in terms of Energy, Delay, Packet Delivery Ratio and Network life time.

Optimization of real-time path finding for material handling of finishing work considering the logistics flow (물류량을 고려한 마감공사 자재운반의 실시간 경로탐색 최적화 연구)

  • Kim, Wansoub;Lee, Dongmin;Kim, Taehoon;Cho, Hunhee;Kang, Kyung-In
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2015.11a
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    • pp.170-171
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    • 2015
  • Resource procurement and material handling are considered as a significant part of construction project especially in large or tall building construction site. There are multiple variables that must be considered in a construction site during finishing work such as movement of materials, equipments, and workers. Therefore, it is difficult for construction workers to find the material handling path solely by intuition. The aim of this study is to propose a real-time path finding model suitable for complicated logistics flow in the field. The model explores the optimal transport path of finishing material with its basis on optimization algorithm, and it determines the direction of the Smart Sign. The proposed model is expected to be utilized for planning of efficient finishing material handling.

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Development of a Stress Path Search Model of Evolutionary Structural Optimization Using TIN (점진적 최적화 기법에서 불규칙 삼각망을 이용한 평면구조의 응력경로 탐색모델의 개발)

  • Kim, Nam-Su;Lee, Jeong-Jae;Yoon, Seong-Soo;Kim, Yoon-Soon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.46 no.4
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    • pp.65-71
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    • 2004
  • Stress Path Search Model of Evolutionary Structural Successive Optimization (SPSMESO) using Triangular Irregular Network(TIN) was developed for improving over burden at initial design of ESO and strict stress direction of strut-and-tie model and truss model. TIN was applied for discretizing structures in flexible stress path and segments of TIN was analyzed as one-dimensional line element for calculating stress. Finally, stress path was searched using ESO algorithm. SPSMESO was efficient to express the direction of stress for 2D structure and time saving.

Lifetime Maximization with Cooperative Wireless Energy Sharing in Wireless Multi-Hop Communications (무선 멀티 홉 통신에서 협력적인 무선 에너지 공유를 통한 생존시간 최대화)

  • Choi, Hyun-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.24 no.11
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    • pp.1550-1553
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    • 2020
  • In this paper, we maximize the lifetime of a multi-hop path through a cooperative wireless energy sharing scheme between constituent nodes in a wireless multi-hop communication. Considering a bidirectional multi-hop communication environment, we present an optimization problem to maximize path lifetime by adjusting the amount of energy each node needs to share with its neighboring nodes. On the basis of solidarity property, i.e., the lifetime of the multi-hop path is maximized when the lifetimes of all nodes are the same, we convert the considered optimization problem into a linear programming problem and solve it easily. Simulation result shows that the proposed two-way wireless energy sharing method maximizes the path lifetime of multi-hop communications and approximately doubles the path lifetime compared with the one-way energy sharing method.

Improvement of Ant Colony Optimization Algorithm to Solve Traveling Salesman Problem (순회 판매원 문제 해결을 위한 개미집단 최적화 알고리즘 개선)

  • Jang, Juyoung;Kim, Minje;Lee, Jonghwan
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.42 no.3
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    • pp.1-7
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    • 2019
  • It is one of the known methods to obtain the optimal solution using the Ant Colony Optimization Algorithm for the Traveling Salesman Problem (TSP), which is a combination optimization problem. In this paper, we solve the TSP problem by proposing an improved new ant colony optimization algorithm that combines genetic algorithm mutations in existing ant colony optimization algorithms to solve TSP problems in many cities. The new ant colony optimization algorithm provides the opportunity to move easily fall on the issue of developing local optimum values of the existing ant colony optimization algorithm to global optimum value through a new path through mutation. The new path will update the pheromone through an ant colony optimization algorithm. The renewed new pheromone serves to derive the global optimal value from what could have fallen to the local optimal value. Experimental results show that the existing algorithms and the new algorithms are superior to those of existing algorithms in the search for optimum values of newly improved algorithms.

A Study on Torch Path Generation for Laser Cutting Process (레이저 절단공정에서의 토지경로 생성에 관한 연구)

  • Han, Guk-Chan;Na, Seok-Ju
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.6
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    • pp.1827-1835
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    • 1996
  • This paper addresses the problem of a torch path generation for the 2D laser cutting of a stock plate nested with resular or irregular parts. Under the constaint of the relative positions of parts enforced by nesting, the developed torch path algorithm generate feasible cutting path. In this paper, the basic object is a polygon( a many-slide figure) with holes. A part may be represented as a number of line segments connected end-to-end in counterclockwise order, and formed a closed contour as requied for cutting paths. The objective is to tranverse this cutting contours with a minimum path length. This paper proposes a simulated annealing based dtorch path algorithm, that is an improved version of previously suggested TSP models. Since everypiercing point of parts is not fixed in advance, the algorithm solves as relazed optimization problem for the constraint, thich is one of the main features of the proposed algorithm. For aolving the torch path optimization problem, an efficient generation mechanism of neighborhood structure and as annealing shedule were introduced. In this way, a global solution can be obtained in a reasonable time. Seveeral examples are represented to ilustrate the method.

Development of a New Optimal Path Planning Algorithm for Mobile Robots Using the Ant Colony Optimization Method (개미 집단 최적화 기법을 이용한 이동 로봇 최적 경로 생성 알고리즘 개발)

  • Ko, Jong-Hoon;Kim, Joo-Min;Kim, Dae-Won
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1827_1828
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    • 2009
  • In this paper proposes a new algorithm for path planning using the ant colony optimization algorithm. The proposed algorithm is a new hybrid algorithm that composes of the features of the ant colony algorithm method and the Maklink graph method. At first, paths are produced for a mobile robot in a static environment, and then, the midpoints of each obstacles nodes are found using the Maklink graph method. Finally, the shortest path is selected by the ant colony optimization algorithm.

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Large-scale Nonseparabel Convex Optimization:Smooth Case (대규모 비분리 콘벡스 최적화 - 미분가능한 경우)

  • 박구현;신용식
    • Journal of the Korean Operations Research and Management Science Society
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    • v.21 no.1
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    • pp.1-17
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    • 1996
  • There have been considerable researches for solving large-scale separable convex optimization ptoblems. In this paper we present a method for large-scale nonseparable smooth convex optimization problems with block-angular linear constraints. One of them is occurred in reconfiguration of the virtual path network which finds the routing path and assigns the bandwidth of the path for each traffic class in ATM (Asynchronous Transfer Mode) network [1]. The solution is approximated by solving a sequence of the block-angular structured separable quadratic programming problems. Bundle-based decomposition method [10, 11, 12]is applied to each large-scale separable quadratic programming problem. We implement the method and present some computational experiences.

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Partial Path Selection Method in Each Subregion for Routing Path Optimization in SEF Based Sensor Networks (통계적 여과 기법 기반 센서 네트워크에서 라우팅 경로 최적화를 위한 영역별 부분 경로 선택 방법)

  • Park, Hyuk;Cho, Tae-Ho
    • Journal of the Korean Institute of Intelligent Systems
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    • v.22 no.1
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    • pp.108-113
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    • 2012
  • Routing paths are mightily important for the network security in WSNs. To maintain such routing paths, sustained path re-selection and path management are needed. Region segmentation based path selection method (RSPSM) provides a path selection method that a sensor network is divided into several subregions, so that the regional path selection and path management are available. Therefore, RSPSM can reduce energy consumption when the path re-selection process is executed. However, it is hard to guarantee optimized secure routing path at all times since the information using the path re-selection process is limited in scope. In this paper, we propose partial path selection method in each subregion using preselected partial paths made by RSPSM for routing path optimization in SEF based sensor networks. In the proposed method, the base station collects the information of the all partial paths from every subregion and then, evaluates all the candidates that can be the optimized routing path for each node using a evaluation function. After the evaluation process is done, the result is sent to each super DN using the global routing path information (GPI) message. Thus, each super DN provides the optimized secure routing paths using the GPI. We show the effectiveness of the proposed method via the simulation results. We expect that our method can be useful for the improvement of RSPSM.