Research on the Optimization and Simulation of the Shortest Path Based on Algorithm of Dijkstra
Institute of Scientific and Technical Information of China (English)
2010-01-01
<正>Dijkstra algorithm is a theoretical basis to solve transportation network problems of the shortest path, which has a wide range of application in path optimization. Through analyzing traditional Dijkstra algorithm,on account of the insufficiency of this algorithm in path optimization,this paper uses adjacency list and circular linked list with combination to store date,and through the improved quick sorting algorithm for weight sorting, accomplish a quick search to the adjacent node,and so an improved Dijkstra algorithm is got.Then apply it to the optimal path search,and make simulation analysis for this algorithm through the example,also verify the effectiveness of the proposed algorithm.
Using Moore Dijkstra Algorithm with Multi-Agent System to Find Shortest Path over Network
Directory of Open Access Journals (Sweden)
Basem Alrifai
2015-06-01
Full Text Available finding the shortest path over network is very difficult and it is the target for much research, after many researches get the result in many of algorithm and many a mount based on the performance for these algorithm .Shortest paths problems are familiar problems in computer science and mathematics. In these problems, edge weights may represent distances, costs, or any other real-valued quantity that can be added along a path, and that one may wish to minimize. Thus, edge weights are real numbers and the specific operations used are addition to compute the weight of a path and minimum to select the best path weight. In this paper we use the Dijkstra's algorithm with new technique to find the shortest path over network to reduce the time we need to find the best path, in this paper we use node for network with the same value which can be use it to find the shortest path but this depend on the number of transition for every node when the node have high number then the node have the high priority to choose it by using this method we descries the time to find the short path .to make this algorithm more distinguish apply multi-agent system ( Automata with multiplicities to find the short path.
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Subbaraj Potti
2011-01-01
Full Text Available Problem statement: A new multi-objective approach, Strength Pareto Evolutionary Algorithm (SPEA, is presented in this paper to solve the shortest path routing problem. The routing problem is formulated as a multi-objective mathematical programming problem which attempts to minimize both cost and delay objectives simultaneously. Approach: SPEA handles the shortest path routing problem as a true multi-objective optimization problem with competing and noncommensurable objectives. Results: SPEA combines several features of previous multi-objective evolutionary algorithms in a unique manner. SPEA stores nondominated solutions externally in another continuously-updated population and uses a hierarchical clustering algorithm to provide the decision maker with a manageable pareto-optimal set. SPEA is applied to a 20 node network as well as to large size networks ranging from 50-200 nodes. Conclusion: The results demonstrate the capabilities of the proposed approach to generate true and well distributed pareto-optimal nondominated solutions.
Shortest Dijkstra Path Routing Algorithm in WOBAN%WOBAN中最短路径Dijkstra路由算法
Institute of Scientific and Technical Information of China (English)
马应平; 柯赓; 曹文婷
2012-01-01
光纤无线宽带混合接入网（WOBAN）是一种新型的具有前景的混合接入网，通过改进其无线端网络的路由算法能够有效克服WOBAN的瓶颈限制。最小跳路由算法（MHRA）和最小时延路由算法（MDRA）是将Diikstra算法应用在WOBAN前端无线Mesh网（WMN）中的新型路由算法，低负载情况下两算法性能相近，高负载情况下MDRA具有更好的网络性能。通过仿真比较，高负载情况下MDRA的时延和TDR性能明显优于MHRA。%The hybrid Wireless-Optical Broadband Access Network (WOBAN) is a promis- ing architecture for future access networks. The characteristics of the Minimum Delay Routing Algorithm (MDRA) and Dijkstra Minimum Hop Routing Algorithm (MHRA) in the wireless front-end of a WOBAN were investigated. Our performance studies show that MDRA has the similar performance with the MHRA in the situation of low load, while it acts shorter delay and higher TDR than MHRA in the situation of high load.
Efficient shortest-path-tree computation in network routing based on pulse-coupled neural networks.
Qu, Hong; Yi, Zhang; Yang, Simon X
2013-06-01
Shortest path tree (SPT) computation is a critical issue for routers using link-state routing protocols, such as the most commonly used open shortest path first and intermediate system to intermediate system. Each router needs to recompute a new SPT rooted from itself whenever a change happens in the link state. Most commercial routers do this computation by deleting the current SPT and building a new one using static algorithms such as the Dijkstra algorithm at the beginning. Such recomputation of an entire SPT is inefficient, which may consume a considerable amount of CPU time and result in a time delay in the network. Some dynamic updating methods using the information in the updated SPT have been proposed in recent years. However, there are still many limitations in those dynamic algorithms. In this paper, a new modified model of pulse-coupled neural networks (M-PCNNs) is proposed for the SPT computation. It is rigorously proved that the proposed model is capable of solving some optimization problems, such as the SPT. A static algorithm is proposed based on the M-PCNNs to compute the SPT efficiently for large-scale problems. In addition, a dynamic algorithm that makes use of the structure of the previously computed SPT is proposed, which significantly improves the efficiency of the algorithm. Simulation results demonstrate the effective and efficient performance of the proposed approach.
Nordin, Noraimi Azlin Mohd; Omar, Mohd; Sharif, S. Sarifah Radiah
2017-04-01
Companies are looking forward to improve their productivity within their warehouse operations and distribution centres. In a typical warehouse operation, order picking contributes more than half percentage of the operating costs. Order picking is a benchmark in measuring the performance and productivity improvement of any warehouse management. Solving order picking problem is crucial in reducing response time and waiting time of a customer in receiving his demands. To reduce the response time, proper routing for picking orders is vital. Moreover, in production line, it is vital to always make sure the supplies arrive on time. Hence, a sample routing network will be applied on EP Manufacturing Berhad (EPMB) as a case study. The Dijkstra's algorithm and Dynamic Programming method are applied to find the shortest distance for an order picker in order picking. The results show that the Dynamic programming method is a simple yet competent approach in finding the shortest distance to pick an order that is applicable in a warehouse within a short time period.
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
A novel method of global optimal path planning for mobile robot was proposed based on the improved Dijkstra algorithm and ant system algorithm. This method includes three steps: the first step is adopting the MAKLINK graph theory to establish the free space model of the mobile robot, the second step is adopting the improved Dijkstra algorithm to find out a sub-optimal collision-free path, and the third step is using the ant system algorithm to adjust and optimize the location of the sub-optimal path so as to generate the global optimal path for the mobile robot. The computer simulation experiment was carried out and the results show that this method is correct and effective. The comparison of the results confirms that the proposed method is better than the hybrid genetic algorithm in the global optimal path planning.
Directory of Open Access Journals (Sweden)
V.PURUSHOTHAM REDDY
2011-02-01
Full Text Available In computer networks the routing is based on shortest path routing algorithms. Based on its advantages, an alternative method is used known as Genetic Algorithm based routing algorithm, which is highly scalable and insensitive to variations in network topology. Here we propose a coarse-grained parallel genetic algorithm to solve the shortest path routing problem with the primary goal of computation time reduction along with the use of migration scheme. This algorithm is developed and implemented on an MPI cluster. The effects of migration and its performance is studied in this paper.
Shortest Paths and Vehicle Routing
DEFF Research Database (Denmark)
Petersen, Bjørn
This thesis presents how to parallelize a shortest path labeling algorithm. It is shown how to handle Chvátal-Gomory rank-1 cuts in a column generation context. A Branch-and-Cut algorithm is given for the Elementary Shortest Paths Problem with Capacity Constraint. A reformulation of the Vehicle R...... Routing Problem based on partial paths is presented. Finally, a practical application of finding shortest paths in the telecommunication industry is shown.......This thesis presents how to parallelize a shortest path labeling algorithm. It is shown how to handle Chvátal-Gomory rank-1 cuts in a column generation context. A Branch-and-Cut algorithm is given for the Elementary Shortest Paths Problem with Capacity Constraint. A reformulation of the Vehicle...
Nair, T R Gopalakrishnan; Yashoda, M B
2011-01-01
In Internet Routing, the static shortest path (SP) problem has been addressed using well known intelligent optimization techniques like artificial neural networks, genetic algorithms (GAs) and particle swarm optimization. Advancement in wireless communication lead more and more mobile wireless networks, such as mobile networks [mobile ad hoc networks (MANETs)] and wireless sensor networks. Dynamic nature of the network is the main characteristic of MANET. Therefore, the SP routing problem in MANET turns into dynamic optimization problem (DOP). Here the nodes ae made aware of the environmental condition, thereby making it intelligent, which goes as the input for GA. The implementation then uses GAs with immigrants and memory schemes to solve the dynamic SP routing problem (DSPRP) in MANETS. In our paper, once the network topology changes, the optimal solutions in the new environment can be searched using the new immigrants or the useful information stored in the memory. Results shows GA with new immigrants sho...
An Evaluation of Potentials of Genetic Algorithm in Shortest Path Problem
Hassany Pazooky, S.; Rahmatollahi Namin, Sh; Soleymani, A.; Samadzadegan, F.
2009-04-01
One of the most typical issues considered in combinatorial systems in transportation networks, is the shortest path problem. In such networks, routing has a significant impact on the network's performance. Due to natural complexity in transportation networks and strong impact of routing in different fields of decision making, such as traffic management and vehicle routing problem (VRP), appropriate solutions to solve this problem are crucial to be determined. During last years, in order to solve the shortest path problem, different solutions are proposed. These techniques are divided into two categories of classic and evolutionary approaches. Two well-known classic algorithms are Dijkstra and A*. Dijkstra is known as a robust, but time consuming algorithm in finding the shortest path problem. A* is also another algorithm very similar to Dijkstra, less robust but with a higher performance. On the other hand, Genetic algorithms are introduced as most applicable evolutionary algorithms. Genetic Algorithm uses a parallel search method in several parts of the domain and is not trapped in local optimums. In this paper, the potentiality of Genetic algorithm for finding the shortest path is evaluated by making a comparison between this algorithm and classic algorithms (Dijkstra and A*). Evaluation of the potential of these techniques on a transportation network in an urban area shows that due to the problem of classic methods in their small search space, GA had a better performance in finding the shortest path.
Traffic-engineering-aware shortest-path routing and its application in IP-over-WDM networks [Invited
Lee, Youngseok; Mukherjee, Biswanath
2004-03-01
Single shortest-path routing is known to perform poorly for Internet traffic engineering (TE) where the typical optimization objective is to minimize the maximum link load. Splitting traffic uniformly over equal-cost multiple shortest paths in open shortest path first and intermediate system-intermediate system protocols does not always minimize the maximum link load when multiple paths are not carefully selected for the global traffic demand matrix. However, a TE-aware shortest path among all the equal-cost multiple shortest paths between each ingress-egress pair can be selected such that the maximum link load is significantly reduced. IP routers can use the globally optimal TE-aware shortest path without any change to existing routing protocols and without any serious configuration overhead. While calculating TE-aware shortest paths, the destination-based forwarding constraint at a node should be satisfied, because an IP router will forward a packet to the next hop toward the destination by looking up the destination prefix. We present a mathematical problem formulation for finding a set of TE-aware shortest paths for the given network as an integer linear program, and we propose a simple heuristic for solving large instances of the problem. Then we explore the usage of our proposed algorithm for the integrated TE method in IP-over-WDM networks. The proposed algorithm is evaluated through simulations in IP networks as well as in IP-over-WDM networks.
A shortest path algorithm for moving objects in spatial network databases
Institute of Scientific and Technical Information of China (English)
Xiaolan Yin; Zhiming Ding; Jing Li
2008-01-01
One of the most important kinds of queries in Spatial Network Databases (SNDB) to support location-based services (LBS) is the shortest path query. Given an object in a network, e.g. A location of a car on a road network, and a set of objects of interests, e.g. Hotels,gas station, and car, the shortest path query returns the shortest path from the query object to interested objects. The studies of shortest path query have two kinds of ways, online processing and preprocessing. The studies of preprocessing suppose that the interest objects are static. This paper proposes a shortest path algorithm with a set of index structures to support the situation of moving objects. This algorithm can transform a dynamic problem to a static problem. In this paper we focus on road networks. However, our algorithms do not use any domain specific information, and therefore can be applied to any network. This algorithm's complexity is O(klog2i), and traditional Dijkstra's complexity is O((I + k)2).
Logistics Distribution Shortest Path Based on Dijkstra Algorithm%基于Dijkstra算法的物流配送最短路径算法研究
Institute of Scientific and Technical Information of China (English)
王华
2011-01-01
根据城市交通网络的特点,运用结点一弧段一有向线结构描述交通网络,利用动态分段技术建立了基于ARC-GIS的配货网络数据库,充分考虑了配货路线短、用时少、费用低的特点,运用Dijkstra算法实现物流配送最短路径算法,提高了城市物流配送的便利性和高效性.%Establish a logistics distribution database based on ArcGIS according to the characteristics of urban traffic network, using node-arc description of transport, achieve logistics distribution shortest path based on dijkstra considering of less rount/time/cost, improve the convenience of ueban logistics distribution efficiency.
An Investigation of Using Parallel Genetic Algorithm for Solving the Shortest Path Routing Problem
Directory of Open Access Journals (Sweden)
Salman Yussof
2011-01-01
Full Text Available Problem statement: Shortest path routing is the type of routing widely used in computer network nowadays. Even though shortest path routing algorithms are well established, other alternative methods may have their own advantages. One such alternative is to use a GA-based routing algorithm. According to previous researches, GA-based routing algorithm has been found to be more scalable and insensitive to variations in network topologies. However, it is also known that GA-based routing algorithm is not fast enough for real-time computation. Approach: To improve the computation time of GA-based routing algorithm, this study proposes a coarse-grained parallel GA routing algorithm for solving the shortest path routing problem. The proposed algorithm is evaluated using simulation where the proposed algorithm is executed on networks with various topologies and sizes. The parallel computation is performed using an MPI cluster. Three different experiments were conducted to identify the best value for the migration rate, the accuracy and execution time with respect to the number of computing nodes and speedup achieved as compared to the serial version of the same algorithm. Results: The result of the simulation shows that the best result is achieved for a migration rate around 0.1 and 0.2. The experiments also show that with larger number of computing nodes, accuracy decreases linearly, but computation time decreases exponentially, which justifies the use parallel implementation of GA to improve the speed of GA-based routing algorithm. Finally, the experiments also show that the proposed algorithm is able to achieve a speedup of up to 818.11% on the MPI cluster used to run the simulation. Conclusion/Recommendations: We have successfully shown that the performance of GA-based shortest path routing algorithm can be improved by using a coarse-grained parallel GA implementation. Even though in this study the proposed algorithm is executed
Self-organization and solution of shortest-path optimization problems with memristive networks
Pershin, Yuriy V.; Di Ventra, Massimiliano
2013-07-01
We show that memristive networks, namely networks of resistors with memory, can efficiently solve shortest-path optimization problems. Indeed, the presence of memory (time nonlocality) promotes self organization of the network into the shortest possible path(s). We introduce a network entropy function to characterize the self-organized evolution, show the solution of the shortest-path problem and demonstrate the healing property of the solution path. Finally, we provide an algorithm to solve the traveling salesman problem. Similar considerations apply to networks of memcapacitors and meminductors, and networks with memory in various dimensions.
Tawanda’s non- iterative optimal tree algorithm for shortest route problems
Directory of Open Access Journals (Sweden)
Trust Tawanda
2013-03-01
Full Text Available So many algorithms have been proposed to solve the shortest path in road networks, in this paper, an algorithm is developed to solve shortest route problems. The algorithm is being demonstrated through solving of various network problems. The principle of the algorithm consist in transforming the graph into a tree by means of arc and node replication, thereby expanding outwards from the source node considering all possible paths up to the destination node. The objective is to develop a method that can be applied in directed and non-directed graphs.
THE USE OF GIS TECHNOLOGY TO IDENTIFY THE SHORTEST TRAVEL PATHS. CASE STUDY: THE CITY OF CRAIOVA
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DANIEL SIMULESCU
2012-04-01
Full Text Available In a city with a population of 298.928 inhabitants (January 2009, about 278.7 km of road (without the northern ring road and a road density of 3.1 km/km2, identifying the optimal routes for moving vehicles is a necessary operation under the temporary removal of use (28 months, from March 2011 of some street sectors in the downtown area, which is currently the subject of an infrastructure modernization work, in order to streamline the cars traffic.The optimal routes were identified using Network Analyst extension of ArcGIS Desktop 9.2 software, which calculated the shortest paths between a point of departure and an arrival one, using distance as impedance. In this case the points between which it was intended to identify the shortest routes were selected taking into account the fact that much of the Craiova’s population located in the north – western neighborhoods, faces traffic problems while they are moving toward the center of city. Therefore, this material is intended to be a support, resulted in some maps, in order to identity and choose the best travel route.
GENERALIZATION OF DIJKSTRAâS ALGORITHM FOR EXTRACTION OF SHORTEST PATHS IN DIRECTED MULTIGRAPHS
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Siddhartha Sankar Biswas
2013-01-01
Full Text Available The classical Dijkstraâs algorithm to find the shortest path in graphs is not applicable to multigraphs. In this study the authors generalize the classical Dijkstraâs algorithm to make it applicable to directed multigraphs. The modified algorithm is called by Generalized Dijkstraâs algorithm or GD Algorithm (GDA in short. The GDA outputs the shortest paths and the corresponding min cost. It is claimed that GDA may play a major role in many application areas of computer science, communication, transportation systems, in particular in those networks which cannot be modeled into graphs but into multigraphs."
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Kohei Arai
2011-12-01
Full Text Available Autonomous Eye Based Electric Wheel Chair: EBEWC control system which allows handicap person (user to control their EWC with their eyes only is proposed. Using EBEWC, user can move to anywhere they want on a same floor in a hospital autonomously with obstacle avoidance with visible camera and ultrasonic sensor. User also can control EBEWC by their eyes. The most appropriate route has to be determined with avoiding obstacles and then autonomous real time control has to be done. Such these processing time and autonomous obstacle avoidance together with the most appropriate route determination are important for the proposed EBEWC. All the required performances are evaluated and validated. Obstacles can be avoided using acquired images with forward looking camera. The proposed EBEWC system allows creation of floor layout map that contains obstacles locations in a real time basis. The created and updated maps can be share by the electric wheel chairs on a same floor of a hospital. Experimental data show that the system allows computer input (more than 80 keys almost perfectly and electric wheel chair can be controlled with human eyes-only safely.
An Improved Physarum polycephalum Algorithm for the Shortest Path Problem
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Xiaoge Zhang
2014-01-01
Full Text Available Shortest path is among classical problems of computer science. The problems are solved by hundreds of algorithms, silicon computing architectures and novel substrate, unconventional, computing devices. Acellular slime mould P. polycephalum is originally famous as a computing biological substrate due to its alleged ability to approximate shortest path from its inoculation site to a source of nutrients. Several algorithms were designed based on properties of the slime mould. Many of the Physarum-inspired algorithms suffer from a low converge speed. To accelerate the search of a solution and reduce a number of iterations we combined an original model of Physarum-inspired path solver with a new a parameter, called energy. We undertook a series of computational experiments on approximating shortest paths in networks with different topologies, and number of nodes varying from 15 to 2000. We found that the improved Physarum algorithm matches well with existing Physarum-inspired approaches yet outperforms them in number of iterations executed and a total running time. We also compare our algorithm with other existing algorithms, including the ant colony optimization algorithm and Dijkstra algorithm.
An improved Physarum polycephalum algorithm for the shortest path problem.
Zhang, Xiaoge; Wang, Qing; Adamatzky, Andrew; Chan, Felix T S; Mahadevan, Sankaran; Deng, Yong
2014-01-01
Shortest path is among classical problems of computer science. The problems are solved by hundreds of algorithms, silicon computing architectures and novel substrate, unconventional, computing devices. Acellular slime mould P. polycephalum is originally famous as a computing biological substrate due to its alleged ability to approximate shortest path from its inoculation site to a source of nutrients. Several algorithms were designed based on properties of the slime mould. Many of the Physarum-inspired algorithms suffer from a low converge speed. To accelerate the search of a solution and reduce a number of iterations we combined an original model of Physarum-inspired path solver with a new a parameter, called energy. We undertook a series of computational experiments on approximating shortest paths in networks with different topologies, and number of nodes varying from 15 to 2000. We found that the improved Physarum algorithm matches well with existing Physarum-inspired approaches yet outperforms them in number of iterations executed and a total running time. We also compare our algorithm with other existing algorithms, including the ant colony optimization algorithm and Dijkstra algorithm.
Institute of Scientific and Technical Information of China (English)
李世兴; 王宏; 周桂平
2015-01-01
WirelessHART protocol presents graph route mechanism without providing the specific realization algorithm.Aiming at the features of graph route in WirelessHART protocol,integrating Dijkstra algorithm,R-Dijkstra algorithm was suitable for graph route realization.R-Dijkstra algorithm defined WirelessHART network as a connected graph. By means of introducing redundancy parameter and route optimization goal,R-Dijkstra algorithm can select the transmission path.The graph route mechanism and R-Di-jkstra algorithm steps described the algorithm realization process. The application example confirms that R-Dijkstra algorithm can meet the demands of graph routes.%在WirelessHART协议中，提出了图路由的路由机制，但并未给出具体的实现算法。针对WirelessHART协议中图路由的特点，结合Dijkstra算法，设计了一种适用于图路由实现的R-Dijkstra算法。 R-Dijkstra算法把WirelessHART网络定义为一个非负权重的连通图，通过引入冗余度参数和路径优化目标，实现了图路由传输路径选择。描述了图路由机制和算法步骤，给出了算法实现过程。应用实例表明，该算法能够满足图路由的要求。
Finding Community Structure in Networks Using a Shortest-Path-Based k-Means Algorithm
Institute of Scientific and Technical Information of China (English)
Jinglu GAO
2013-01-01
We consider the problem of detecting the community structure in a complex network,groups of nodes with a higher-than-average density of edges connecting them.In this paper we use the simulated annealing strategy to maximize the modularity,which has been indicated as a robust benefit function,associating with a shortest-path-based k-means iterative procedure for network partition.The proposed algorithm can not only find the communities,but also identify the nodes which occupy central positions under the metric of the shortest path within the communities to which they belong.The optimal number of communities can be automatically determined without any prior knowledge about the network structure.The applications to both artificial and real-world networks demonstrate the effectiveness of our algorithm.
Experiments with the auction algorithm for the shortest path problem
DEFF Research Database (Denmark)
Larsen, Jesper; Pedersen, Ib
1999-01-01
The auction approach for the shortest path problem (SPP) as introduced by Bertsekas is tested experimentally. Parallel algorithms using the auction approach are developed and tested. Both the sequential and parallel auction algorithms perform significantly worse than a state-of-the-art Dijkstra......-like reference algorithm. Experiments are run on a distributed-memory MIMD class Meiko parallel computer....
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Yunyue He
Full Text Available Emergency evacuation aims to transport people from dangerous places to safe shelters as quickly as possible. Police play an important role in the evacuation process, as they can handle traffic accidents immediately and help people move smoothly on roads. This paper investigates an evacuation routing problem that involves police resource allocation. We propose a novel k-th-shortest-path-based technique that uses explicit congestion control to optimize evacuation routing and police resource allocation. A nonlinear mixed-integer programming model is presented to formulate the problem. The model's objective is to minimize the overall evacuation clearance time. Two algorithms are given to solve the problem. The first one linearizes the original model and solves the linearized problem with CPLEX. The second one is a heuristic algorithm that uses a police resource utilization efficiency index to directly solve the original model. This police resource utilization efficiency index significantly aids in the evaluation of road links from an evacuation throughput perspective. The proposed algorithms are tested with a number of examples based on real data from cities of different sizes. The computational results show that the police resource utilization efficiency index is very helpful in finding near-optimal solutions. Additionally, comparing the performance of the heuristic algorithm and the linearization method by using randomly generated examples indicates that the efficiency of the heuristic algorithm is superior.
Using Link Analysis Technique with a Modified Shortest-Path Algorithm to Fight Money Laundering
Institute of Scientific and Technical Information of China (English)
CHEN Yunkai; MAI Quanwen; LU Zhengding
2006-01-01
Effective link analysis techniques are needed to help law enforcement and intelligence agencies fight money laundering.This paper presents a link analysis technique that uses a modified shortest-path algorithms to identify the strongest association paths between entities in a money laundering network.Based on two-tree Dijkstra and Priority-First-Search (PFS) algorithm, a modified algorithm is presented.To apply the algorithm, a network representation transformation is made first.
Optimal parallel algorithm for shortest-paths problem on interval graphs
Institute of Scientific and Technical Information of China (English)
MISHRA P.K.
2004-01-01
This paper presents an efficient parallel algorithm for the shortest-path problem in interval graph for computing shortest-paths in a weighted interval graph that runs in O(n) time with n intervals in a graph. A linear processor CRCW algorithm for determining the shortest-paths in an interval graphs is given.
Dynamic Shortest Path Monitoring in Spatial Networks
Institute of Scientific and Technical Information of China (English)
Shuo Shang; Lisi Chen; Zhe-Wei Wei; Dan-Huai Guo; Ji-Rong Wen
2016-01-01
With the increasing availability of real-time traﬃc information, dynamic spatial networks are pervasive nowa-days and path planning in dynamic spatial networks becomes an important issue. In this light, we propose and investigate a novel problem of dynamically monitoring shortest paths in spatial networks (DSPM query). When a traveler aims to a des-tination, his/her shortest path to the destination may change due to two reasons: 1) the travel costs of some edges have been updated and 2) the traveler deviates from the pre-planned path. Our target is to accelerate the shortest path computing in dynamic spatial networks, and we believe that this study may be useful in many mobile applications, such as route planning and recommendation, car navigation and tracking, and location-based services in general. This problem is challenging due to two reasons: 1) how to maintain and reuse the existing computation results to accelerate the following computations, and 2) how to prune the search space effectively. To overcome these challenges, filter-and-refinement paradigm is adopted. We maintain an expansion tree and define a pair of upper and lower bounds to prune the search space. A series of optimization techniques are developed to accelerate the shortest path computing. The performance of the developed methods is studied in extensive experiments based on real spatial data.
Institute of Scientific and Technical Information of China (English)
殷招伟; 戴文博; 钱俊彦
2015-01-01
The interdisciplinary application of intelligent transportation system comes into being just to meet people’s growing demand.The analysis of shortest path is the key problem in the application of VRGS (Vehicle Route Guidance System), the Dijkstra algorithm is the common algorithm to solve this problem effectively. Combined two-tree Dijkstra algorithm and multi-core and multi-threading technology, this paper optimizes and improves the traditional Dijkstra algorithm. And it discusses the application of the algorithm in VRGS.At last, this paper poves its practicality and efficiency by simulating the shortest path search process of Guilin.%为了满足人们日益增长的出行需求，跨学科的智能交通系统应运而生。最短路径分析是GIS车辆诱导系统应用的关键问题，Dijkstra 算法是解决该问题的常用算法。文章结合二树 Dijkstra 算法的思想和现代多核多线程的技术，对 Dijkstra算法进行了优化与改进，并对该算法在车辆诱导系统中的应用进行了探讨。该系统以桂林市为例模拟了最短路径搜过程，证明该算法的高效性和实用性。
Energy-Efficient Shortest Path Algorithms for Convergecast in Sensor Networks
Augustine, John; Loden, Philip; Lodha, Sachin; Roy, Sasanka
2009-01-01
We introduce a variant of the capacitated vehicle routing problem that is encountered in sensor networks for scientific data collection. Consider an undirected graph $G=(V \\cup \\{\\mathbf{sink}\\},E)$. Each vertex $v \\in V$ holds a constant-sized reading normalized to 1 byte that needs to be communicated to the $\\mathbf{sink}$. The communication protocol is defined such that readings travel in packets. The packets have a capacity of $k$ bytes. We define a {\\em packet hop} to be the communication of a packet from a vertex to its neighbor. Each packet hop drains one unit of energy and therefore, we need to communicate the readings to the $\\mathbf{sink}$ with the fewest number of hops. We show this problem to be NP-hard and counter it with a simple distributed $(2-\\frac{3}{2k})$-approximation algorithm called {\\tt SPT} that uses the shortest path tree rooted at the $\\mathbf{sink}$. We also show that {\\tt SPT} is absolutely optimal when $G$ is a tree and asymptotically optimal when $G$ is a grid. Furthermore, {\\tt ...
Design and Implementation of Bidirectional Dijkstra Algorithm
Institute of Scientific and Technical Information of China (English)
付梦印; 李杰; 周培德
2003-01-01
Bidirectional Dijkstra algorithm whose time complexity is (1)/(8)O(n2) is proposed. The theory foundation is that the classical Dijkstra algorithm has not any directional feature during searching the shortest path. The algorithm takes advantage of the adjacent link and the mechanism of bidirectional search, that is, the algorithm processes the positive search from start point to destination point and the negative search from destination point to start point at the same time. Finally, combining with the practical application of route-planning algorithm in embedded real-time vehicle navigation system (ERTVNS), one example of its practical applications is given, analysis in theory and the experimental results show that compared with the Dijkstra algorithm, the new algorithm can reduce time complexity, and guarantee the searching precision, it satisfies the needs of ERTVNS.
Dynamic Shortest Path Algorithms for Hypergraphs
2014-01-01
hypergraphs, energy efficient routing in multichannel multiradio networks, and the Enron email data set. The experiment with the Enron email data set...efficient routing inmultichannel multiradio networks, and the Enron email data set. The experiment with the Enron email data set illustrates the application...FOR HYPERGRAPHS 3 of each actor. In Section VII, we apply the proposed shortest hy- perpath algorithms to the Enron e-mail data set. We propose a
Optimal Route Based Advanced Algorithm using Hot Link Split Multi-Path Routing Algorithm
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Akhilesh A. Waoo
2014-07-01
Full Text Available Present research work describes advancement in standard routing protocol AODV for mobile ad-hoc networks. Our mechanism sets up multiple optimal paths with the criteria of bandwidth and delay to store multiple optimal paths in the network. At time of link failure, it will switch to next available path. We have used the information that we get in the RREQ packet and also send RREP packet to more than one path, to set up multiple paths, It reduces overhead of local route discovery at the time of link failure and because of this End to End Delay and Drop Ratio decreases. The main feature of our mechanism is its simplicity and improved efficiency. This evaluates through simulations the performance of the AODV routing protocol including our scheme and we compare it with HLSMPRA (Hot Link Split Multi-Path Routing Algorithm Algorithm. Indeed, our scheme reduces routing load of network, end to end delay, packet drop ratio, and route error sent. The simulations have been performed using network simulator OPNET. The network simulator OPNET is discrete event simulation software for network simulations which means it simulates events not only sending and receiving packets but also forwarding and dropping packets. This modified algorithm has improved efficiency, with more reliability than Previous Algorithm.
A genetic algorithm for the pareto optimal solution set of multi-objective shortest path problem
Institute of Scientific and Technical Information of China (English)
HU Shi-cheng; XU Xiao-fei; ZHAN De-chen
2005-01-01
Unlike the shortest path problem that has only one optimal solution and can be solved in polynomial time, the multi-objective shortest path problem (MSPP) has a set of pareto optimal solutions and cannot be solved in polynomial time. The present algorithms focused mainly on how to obtain a precisely pareto optimal solution for MSPP resulting in a long time to obtain multiple pareto optimal solutions with them. In order to obtain a set of satisfied solutions for MSPP in reasonable time to meet the demand of a decision maker, a genetic algorithm MSPP-GA is presented to solve the MSPP with typically competing objectives, cost and time, in this paper. The encoding of the solution and the operators such as crossover, mutation and selection are developed.The algorithm introduced pareto domination tournament and sharing based selection operator, which can not only directly search the pareto optimal frontier but also maintain the diversity of populations in the process of evolutionary computation. Experimental results show that MSPP-GA can obtain most efficient solutions distributed all along the pareto frontier in less time than an exact algorithm. The algorithm proposed in this paper provides a new and effective method of how to obtain the set of pareto optimal solutions for other multiple objective optimization problems in a short time.
Dynamic Shortest Path Algorithms for Hypergraphs
2012-01-01
Performance comparison of algorithms for the dynamic shortest path problem,” IEICE Transactions on Fundamentals of Electronics , Communications and...computation,” IEEE/ACM Transactions on Networking, vol. 8, no. 6, pp. 734–746, 2000. [8] G. Ramalingam and T. Reps, “An incremental algorithm for a...multihop performance,” IEEE Transactions on Mobile Computing, pp. 337–348, 2003. [17] S. Chachulski, M. Jennings, S. Katti, and D. Katabli, “Trading
Directory of Open Access Journals (Sweden)
Meenakshi R Patel
2012-03-01
Full Text Available ACO algorithms for datagram networks was given by Di Caro Dorigo, in year 1996. Basic mechanisms in typical ACO routing algorithms is Ant-like agents are proactively generated at the nodes to find/check paths toward assigned destinations Ants move hop-by-hop according to a exploratory routing policy based on the local routing .After reaching their destination, ants retrace their path and update nodes routing information according to the quality of the path. Routing information is statistical estimates of the time-to-go to the destination maintained in pheromone arrays. Data are probabilistically spread over the paths according to their estimated quality as stored in the pheromone variables. AntNet algorithms may cause the network congestion and stagnation as the routing table converges. In this paper we perform a survey on modified AntNet routing algorithm using Multiple Ant-Colony Optimization. Multiple ant colonies with different pheromone updating mechanism have different searching traits. By leveraging this feature, much of work is done by designing a set of adaptive rules to facilitate the collaboration between these colonies. This approach can balance the diversity and convergence of solutions generated by different ant colonies and also overcome the problem of Stagnation.
A minimum resource neural network framework for solving multiconstraint shortest path problems.
Zhang, Junying; Zhao, Xiaoxue; He, Xiaotao
2014-08-01
Characterized by using minimum hard (structural) and soft (computational) resources, a novel parameter-free minimal resource neural network (MRNN) framework is proposed for solving a wide range of single-source shortest path (SP) problems for various graph types. The problems are the k-shortest time path problems with any combination of three constraints: time, hop, and label constraints, and the graphs can be directed, undirected, or bidirected with symmetric and/or asymmetric traversal time, which can be real and time dependent. Isomorphic to the graph where the SP is to be sought, the network is activated by generating autowave at source neuron and the autowave travels automatically along the paths with the speed of a hop in an iteration. Properties of the network are studied, algorithms are presented, and computation complexity is analyzed. The framework guarantees globally optimal solutions of a series of problems during the iteration process of the network, which provides insight into why even the SP is still too long to be satisfied. The network facilitates very large scale integrated circuit implementation and adapt to very large scale problems due to its massively parallel processing and minimum resource utilization. When implemented in a sequentially processing computer, experiments on synthetic graphs, road maps of cities of the USA, and vehicle routing with time windows indicate that the MRNN is especially efficient for large scale sparse graphs and even dense graphs with some constraints, e.g., the CPU time taken and the iteration number used for the road maps of cities of the USA is even less than ∼ 2% and 0.5% that of the Dijkstra's algorithm.
a Modified Genetic Algorithm for Finding Fuzzy Shortest Paths in Uncertain Networks
Heidari, A. A.; Delavar, M. R.
2016-06-01
In realistic network analysis, there are several uncertainties in the measurements and computation of the arcs and vertices. These uncertainties should also be considered in realizing the shortest path problem (SPP) due to the inherent fuzziness in the body of expert's knowledge. In this paper, we investigated the SPP under uncertainty to evaluate our modified genetic strategy. We improved the performance of genetic algorithm (GA) to investigate a class of shortest path problems on networks with vague arc weights. The solutions of the uncertain SPP with considering fuzzy path lengths are examined and compared in detail. As a robust metaheuristic, GA algorithm is modified and evaluated to tackle the fuzzy SPP (FSPP) with uncertain arcs. For this purpose, first, a dynamic operation is implemented to enrich the exploration/exploitation patterns of the conventional procedure and mitigate the premature convergence of GA technique. Then, the modified GA (MGA) strategy is used to resolve the FSPP. The attained results of the proposed strategy are compared to those of GA with regard to the cost, quality of paths and CPU times. Numerical instances are provided to demonstrate the success of the proposed MGA-FSPP strategy in comparison with GA. The simulations affirm that not only the proposed technique can outperform GA, but also the qualities of the paths are effectively improved. The results clarify that the competence of the proposed GA is preferred in view of quality quantities. The results also demonstrate that the proposed method can efficiently be utilized to handle FSPP in uncertain networks.
SHORTEST PATH ARC LENGTH NETWORK USING TRIANGULAR INTUITIONISTIC FUZZY NUMBER
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A.D.CHANDRASEKARAN
2016-04-01
Full Text Available In this paper, an intuitionistic fuzzy shortest path is presented to find the optimal path in a network which a fuzzy number, instead of a positive integer is assigned to each arc length. The algorithm is based on the idea that firstly from all the shortest paths from source to destination, an arc with shortest length is computed and then the Euclidean distance is computed for all the paths with the arc of minimum distance. Finally an illustrative numerical example is given to express the proposed work.
The shortest-path problem analysis and comparison of methods
Ortega-Arranz, Hector; Gonzalez-Escribano, Arturo
2014-01-01
Many applications in different domains need to calculate the shortest-path between two points in a graph. In this paper we describe this shortest path problem in detail, starting with the classic Dijkstra's algorithm and moving to more advanced solutions that are currently applied to road network routing, including the use of heuristics and precomputation techniques. Since several of these improvements involve subtle changes to the search space, it may be difficult to appreciate their benefits in terms of time or space requirements. To make methods more comprehensive and to facilitate their co
Applications to determine the shortest tower BTS distance using Dijkstra algorithm
Mardana, Herwin; Maharani, Septya; Hatta, Heliza Rahmania
2017-02-01
Telecommunications Tower or so-called BTS (Base Transceiver System) Toweris one of the main components in the network infrastructure that has experienced an increase in the number of construction. Telecommunications tower function as a place to put the antenna signal transmitter (access network) to provide communication services to customers around the tower. In addition, other use of telecommunications tower also to place the transmission signal antenna (transport network using microwave technology) for connecting customers with a central area. Therefore, in needed of a decision support system that can provide recommendations planting route of fiber optic cable with the shortest distance in purpose the use of fiber optic cable becoming more efficient. The results of the research were the shortest rule information, showing the distance to be travelled and the map view to enabling users to look at these.
A computational study of routing algorithms for realistic transportation networks
Energy Technology Data Exchange (ETDEWEB)
Jacob, R.; Marathe, M.V.; Nagel, K.
1998-12-01
The authors carry out an experimental analysis of a number of shortest path (routing) algorithms investigated in the context of the TRANSIMS (Transportation Analysis and Simulation System) project. The main focus of the paper is to study how various heuristic and exact solutions, associated data structures affected the computational performance of the software developed especially for realistic transportation networks. For this purpose the authors have used Dallas Fort-Worth road network with very high degree of resolution. The following general results are obtained: (1) they discuss and experimentally analyze various one-one shortest path algorithms, which include classical exact algorithms studied in the literature as well as heuristic solutions that are designed to take into account the geometric structure of the input instances; (2) they describe a number of extensions to the basic shortest path algorithm. These extensions were primarily motivated by practical problems arising in TRANSIMS and ITS (Intelligent Transportation Systems) related technologies. Extensions discussed include--(i) time dependent networks, (ii) multi-modal networks, (iii) networks with public transportation and associated schedules. Computational results are provided to empirically compare the efficiency of various algorithms. The studies indicate that a modified Dijkstra`s algorithm is computationally fast and an excellent candidate for use in various transportation planning applications as well as ITS related technologies.
ESHOPPS: A COMPUTATIONAL TOOL TO AID THE TEACHING OF SHORTEST PATH ALGORITHMS
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S. J. de A. LIMA
2015-07-01
Full Text Available The development of a computational tool called EShoPPS – Environment for Shortest Path Problem Solving, which is used to assist students in understanding the working of Dijkstra, Greedy search and A*(star algorithms is presented in this paper. Such algorithms are commonly taught in graduate and undergraduate courses of Engineering and Informatics and are used for solving many optimization problems that can be characterized as Shortest Path Problem. The EShoPPS is an interactive tool that allows students to create a graph representing the problem and also helps in developing their knowledge of each specific algorithm. Experiments performed with 155 students of undergraduate and graduate courses such as Industrial Engineering, Computer Science and Information Systems have shown that by using the EShoPPS tool students were able to improve their interpretation of investigated algorithms.
Self Avoiding Paths Routing Algorithm in Scale-Free Networks
Rachadi, Abdeljalil; Zahid, Noureddine
2013-01-01
In this paper, we present a new routing algorithm called "the Self Avoiding Paths Routing Algorithm". Its application to traffic flow in scale-free networks shows a great improvement over the so called "efficient routing" protocol while at the same time maintaining a relatively low average packet travel time. It has the advantage of minimizing path overlapping throughout the network in a self consistent manner with a relatively small number of iterations by maintaining an equilibrated path distribution especially among the hubs. This results in a significant shifting of the critical packet generation rate over which traffic congestion occurs, thus permitting the network to sustain more information packets in the free flow state. The performance of the algorithm is discussed both on a Bar\\'abasi-Albert (BA) network and real autonomous system (AS) network data.
The Structure of the Optimal Solution Set on the Shortest Paths for Networks%网络最短的最优解集结构
Institute of Scientific and Technical Information of China (English)
张振坤; 王斌
2007-01-01
The shortest path problem in a network G is to find shortest paths between some specified source vertices and terminal vertices when the lengths of edges are given.The structure of the optimal Solutions set on the shortest paths is studied in this Paper.First,the conditions of having unique shortest path between two distinguished vertices s and t in a network G are discussed;Second,the struetural properties of 2-transformation graph G on the shortest-paths for G are presented heavily.
A Primal-dual Neural Network for Shortest Path Problem
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
The shortest path (SP) problem is a classical combinatorial optimization problem which plays an important role in a packet-switched computer and communication network. A new primal-dual neural network to solve the shortest path problem (PDSPN) is presented in this paper. The proposed neural network combines many features such as no network coefficients set,easy implementation in a VLSI circuit, and is proved to be completely stable to the exact solutions. The simulation example shows its efficiency in finding the "optimum" path(s) for data transmission in computer and communication network.
A O(E) Time Shortest Path Algorithm For Non Negative Weighted Undirected Graphs
Qureshi, Muhammad Aasim; Safdar, Sohail; Akbar, Rehan
2009-01-01
In most of the shortest path problems like vehicle routing problems and network routing problems, we only need an efficient path between two points source and destination, and it is not necessary to calculate the shortest path from source to all other nodes. This paper concentrates on this very idea and presents an algorithm for calculating shortest path for (i) nonnegative weighted undirected graphs (ii) unweighted undirected graphs. The algorithm completes its execution in O(E) for all graphs except few in which longer path (in terms of number of edges) from source to some node makes it best selection for that node. The main advantage of the algorithms is its simplicity and it does not need complex data structures for implementations.
A Study on Selecting the Shortest Routes by Voronoi Diagram in Route Networks of GIS
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
The problems of fast determining shortest paths through a polygonal subdivisionplanar with n vertices are considered in GIS. Distances are measured according to an Euclideanmetric. A geographical information system (GIS)has a collection of nearest neighborhoodoperations and this collection serves as a useful toolbox for spatial analysis. These operationsare undertaken through the Voronoi diagrams. This paper presents a novel algorithm thatconstructs a “shortest route set” with respect to a given source point and a target point byVoronoi diagrams. It will help to improve the efficiency of traditional algorithms, e. g. , Djkstraalgorithm, on selecting the shortest routes. Moreover, the novel algorithm can check theconnectivity in a complex network between the source point and target one.
The Shortest Path with Intelligent Algorithm
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Surachai Panich
2010-01-01
Full Text Available Problem statement: Path planning algorithms need to be developed and implemented in a suitable manner to give better understanding about the intelligent system and also stimulates technological supply to enormous demands in an intelligent vehicle industry. Approach: This study concerned with intelligent path planning using A* search algorithm. Results: This study introduced intelligent path planning with A* search algorithm, which use to generate the most efficient path to goal. The algorithm was tested on simulator. Conclusion: This study is an implementation of a path planning for an intelligent path planning. The implementations are tested and verified with the simulation software. The path planning algorithms were selected for the implementation and to verify them.
Approximation algorithms for curvature-constrained shortest paths
Energy Technology Data Exchange (ETDEWEB)
Wang, Hongyan; Agarwal, P.K. [Duke Univ., Durham, NC (United States)
1996-12-31
Let B be a point robot in the plane, whose path is constrained to have curvature of at most 1, and let {Omega} be a set of polygonal obstacles with n vertices. We study the collision-free, optimal path-planning problem for B. Given a parameter {epsilon}, we present an O((n{sup 2}/{epsilon}{sup 2}) log n)-time algorithm for computing a collision-free, curvature-constrained path between two given positions, whose length is at most (1 + {epsilon}) times the length of an optimal robust path (a path is robust if it remains collision-free even if certain positions on the path are perturbed). Our algorithm thus runs significantly faster than the previously best known algorithm by Jacobs and Canny whose running time is O((n+L/{epsilon}){sup 2} + n{sup 2} (n+1/{epsilon}) log n), where L is the total edge length of the obstacles. More importantly, the running time of our algorithm does not depend on the size of obstacles. The path returned by this algorithm is not necessarily robust. We present an O((n/{epsilon}){sup 2.5} log n)-time algorithm that returns a robust path whose length is at most (1 + {epsilon}) times the length of an optimal robust path. We also give a stronger characterization of curvature-constrained shortest paths, which, apart from being crucial for our algorithm, is interesting in its own right. Roughly speaking, we prove that, except in some special cases, a shortest path touches obstacles only at points that have a visible vertex nearby.
Shortest-path routing algorithm based on selected RSL in WlrelessHART%基于RSL筛选的WirelessHART最短路径路由算法
Institute of Scientific and Technical Information of China (English)
党魁; 沈继忠; 董利达
2012-01-01
无线HART网络协议中提出的Graph路由是同类无线网络中健壮性最好的路由方式之一.针对目前实现该路由方式的算法非常少且性能不佳的现状,提出一种基于BFS的Graph路由算法.该算法得到的路由具有跳间冗余的特点,能够最大限度地增加路由健壮性,并且路径最短；引入RSL作为链路质量衡量标准,剔除质量较差的链路,同时对每跳的邻居数设置上限,保证了路由的健壮性,同时避免了低质量的链路带来的通信资源浪费.此外,论证了协议所没有提及的广播路由存在的必要,并给出了实现算法.%The Graph routing proposed by WirelessHART is one of the routing protocols which with best robustness among all the wireless networks. Since there is little algorithm on Graph routing at present and the routing performance is poor, a shortest-path Graph routing algorithm based on BFS( Breadth-First Search) is presented. The routing algorithm has a character of neighbor redundancies, which can maximize to increase the routing robustness. With the introduction of RSL(Receive Signal Level) as a link quality measurement, removing the links with poor quality, setting an upper limit to the number of neighbors in each hop, both methods are aimed to increase the routing robustness and minimize the waste communication resources. In addition, the necessary of broadcast routing which WirelessHART has not mentioned is demonstrated and the reality algorithm is also proposed.
Optimization of OSPF Routing in IP Networks
Bley, Andreas; Fortz, Bernard; Gourdin, Eric; Holmberg, Kaj; Klopfenstein, Olivier; Pióro, Michał; Tomaszewski, Artur; Ümit, Hakan
The Internet is a huge world-wide packet switching network comprised of more than 13,000 distinct subnetworks, referred to as Autonomous Systems (ASs) autonomous system AS . They all rely on the Internet Protocol (IP) internet protocol IP for transport of packets across the network. And most of them use shortest path routing protocols shortest path routing!protocols , such as OSPF or IS-IS, to control the routing of IP packets routing!of IP packets within an AS. The idea of the routing is extremely simple — every packet is forwarded on IP links along the shortest route between its source and destination nodes of the AS. The AS network administrator can manage the routing of packets in the AS by supplying the so-called administrative weights of IP links, which specify the link lengths that are used by the routing protocols for their shortest path computations. The main advantage of the shortest path routing policy is its simplicity, allowing for little administrative overhead. From the network engineering perspective, however, shortest path routing can pose problems in achieving satisfactory traffic handling efficiency. As all routing paths depend on the same routing metric routing!metric , it is not possible to configure the routing paths for the communication demands between different pairs of nodes explicitly or individually; the routing can be controlled only indirectly and only as a whole by modifying the routing metric. Thus, one of the main tasks when planning such networks is to find administrative link weights that induce a globally efficient traffic routing traffic!routing configuration of an AS. It turns out that this task leads to very difficult mathematical optimization problems. In this chapter, we discuss and describe exact integer programming models and solution approaches as well as practically efficient smart heuristics for such shortest path routing problems shortest path routing!problems .
Multiple object tracking using the shortest path faster association algorithm.
Xi, Zhenghao; Liu, Heping; Liu, Huaping; Yang, Bin
2014-01-01
To solve the persistently multiple object tracking in cluttered environments, this paper presents a novel tracking association approach based on the shortest path faster algorithm. First, the multiple object tracking is formulated as an integer programming problem of the flow network. Then we relax the integer programming to a standard linear programming problem. Therefore, the global optimum can be quickly obtained using the shortest path faster algorithm. The proposed method avoids the difficulties of integer programming, and it has a lower worst-case complexity than competing methods but better robustness and tracking accuracy in complex environments. Simulation results show that the proposed algorithm takes less time than other state-of-the-art methods and can operate in real time.
Multiple Object Tracking Using the Shortest Path Faster Association Algorithm
Directory of Open Access Journals (Sweden)
Zhenghao Xi
2014-01-01
Full Text Available To solve the persistently multiple object tracking in cluttered environments, this paper presents a novel tracking association approach based on the shortest path faster algorithm. First, the multiple object tracking is formulated as an integer programming problem of the flow network. Then we relax the integer programming to a standard linear programming problem. Therefore, the global optimum can be quickly obtained using the shortest path faster algorithm. The proposed method avoids the difficulties of integer programming, and it has a lower worst-case complexity than competing methods but better robustness and tracking accuracy in complex environments. Simulation results show that the proposed algorithm takes less time than other state-of-the-art methods and can operate in real time.
Auction Algorithm for Shortest Paths and its Application in Route Guidance%最短路径Auction算法及其在路径诱导中的应用
Institute of Scientific and Technical Information of China (English)
杜牧青; 程琳
2012-01-01
Taking Dijkstra's algorithm as a reference, the algorithm s performance was tested in the "one-to-one" shortest path problems via a corresponding computer program coded in C#. The computational tests on the actual networks and random networks show the advantages of Auction algorithm' s principle. But its overall performance is not as good as labeling algorithms, I. E. Some computational steps of iteration are repeated too many times, affecting the efficiency. Reducing these redundant operations, Auction algorithm could be improved.%通过采用C#语言程序,对比传统路径算法,并在实际道路网络和随机网络中进行了试验,测试了算法在求解网络“一对一”最短路径问题时的运算性能.结果表明,Auction算法在求解此类问题时,体现算法自身原理的优势,虽然整体性能表现不及经典的路径算法,即迭代步骤略多,但仍有改进的余地.
Institute of Scientific and Technical Information of China (English)
DING Yingqiang; DU Liufeng; YANG Ting; SUN Yugeng
2009-01-01
Sensor localization is crucial for the configuration and applications of wireless sensor network (WSN). A novel distributed localization algorithm, MDS-DC was proposed for wireless sensor network based on multidi-mensional scaling (MDS) and the shortest path distance correction. In MDS-DC, several local positioning regions with reasonable distribution were firstly constructed by an adaptive search algorithm, which ensures the mergence between the local relative maps of the adjacent local position regions and can reduce the number of common nodes in the network. Then, based on the relationships between the estimated distances and actual distances of anchors, the distance estimation vectors of sensors around anchors were corrected in each local positioning region. During the computations of the local relative coordinates, an iterative process, which is the combination of classical MDS algorithm and SMACOF algorithm, was applied. Finally, the global relative positions or absolute positions of sen-sors were obtained through merging the relative maps of all local positioning regions. Simulation results show that MDS-DC has better performances in positioning precision, energy efficiency and robustness to range error, which can meet the requirements of applications for sensor localization in WSN.
Partial order approach to compute shortest paths in multimodal networks
Ensor, Andrew
2011-01-01
Many networked systems involve multiple modes of transport. Such systems are called multimodal, and examples include logistic networks, biomedical phenomena, manufacturing process and telecommunication networks. Existing techniques for determining optimal paths in multimodal networks have either required heuristics or else application-specific constraints to obtain tractable problems, removing the multimodal traits of the network during analysis. In this paper weighted coloured--edge graphs are introduced to model multimodal networks, where colours represent the modes of transportation. Optimal paths are selected using a partial order that compares the weights in each colour, resulting in a Pareto optimal set of shortest paths. This approach is shown to be tractable through experimental analyses for random and real multimodal networks without the need to apply heuristics or constraints.
Shortest Tree Routing With Security In Wireless Sensor Networks
Directory of Open Access Journals (Sweden)
P.T Arshad
2014-12-01
Full Text Available We propose STR to resolve the main reasons of overall network performance degradation of ZTR, which are the detour path problem and the traffic concentration problem. Second, we prove that the 1-hop neighbor nodes used by STR improve the routing path efficiency and alleviate the traffic load concentrated on tree links in ZTR. Third, we analyze the performance of ZTR, STR, and AODV by differentiating the network conditions such as network density, ZigBee network constraints, traffic types, and the network traffic. For modification security purpose we are also encrypting the data packets during transmission. So that the intermediate nodes are not able to view the data during transmission. For Encryption process, we are using RC4 Algorithm. Short cut tree routing is used for minimizing the routing path from source to destination.
2012-09-13
Matrix produced by Wimer’s Algorithm # of Arcs j 1 2 3 . . . q 2 P1(2) P2(2) P3 (2) . . . Pq(2) 3 P1(3) P2(3) P3 (3) Pq(3) Node # u 4 P1(4) P2(4) P3 (4...Pq(4) ... ... . . . ... N P1(N) P2(N) P3 (N) . . . Pq(N) Assign another matrix Z, call each of its elements Zj(u), where each element is 25 Table 5...chooses ”contract” car- riers for long-term partnerships ; thus the need to model schedules is negated. Look at [10] for one detailed model of
Effect of Congestion Costs on Shortest Paths Through Complex Networks
Ashton, Douglas J.; Jarrett, Timothy C.; Johnson, Neil F.
2005-02-01
We analyze analytically the effect of congestion costs within a physically relevant, yet exactly solvable, network model featuring central hubs. These costs lead to a competition between centralized and decentralized transport pathways. In stark contrast to conventional no-cost networks, there now exists an optimal number of connections to the central hub in order to minimize the shortest path. Our results shed light on an open problem in biology, informatics, and sociology, concerning the extent to which decentralized versus centralized design benefits real-world complex networks.
Directory of Open Access Journals (Sweden)
K. Kumaravel
2015-05-01
Full Text Available Wireless Mesh Network (WMN uses the latest technology which helps in providing end users a high quality service referred to as the Internet’s “last mile”. Also considering WMN one of the most important technologies that are employed is multicast communication. Among the several issues routing which is significantly an important issue is addressed by every WMN technologies and this is done during the process of data transmission. The IEEE 802.11s Standard entails and sets procedures which need to be followed to facilitate interconnection and thus be able to devise an appropriate WMN. There has been introduction of several protocols by many authors which are mainly devised on the basis of machine learning and artificial intelligence. Multi-path routing may be considered as one such routing method which facilitates transmission of data over several paths, proving its capabilities as a useful strategy for achieving reliability in WMN. Though, multi-path routing in any manner cannot really guarantee deterministic transmission. As here there are multiple paths available for enabling data transmission from source to destination node. The algorithm that had been employed before in the studies conducted did not take in to consideration routing metrics which include energy aware metrics that are used for path selection during transferring of data. The following study proposes use of the hybrid multipath routing algorithm while taking in to consideration routing metrics which include energy, minimal loss for efficient path selection and transferring of data. Proposed algorithm here has two phases. In the first phase prim’s algorithm has been proposed so that in networks route discovery may be possible. For the second one the Hybrid firefly algorithm which is based on harmony search has been employed for selection of the most suitable and best through proper analysis of metrics which include energy awareness and minimal loss for every path that has
An improved real-time endovascular guidewire position simulation using shortest path algorithm.
Qiu, Jianpeng; Qu, Zhiyi; Qiu, Haiquan; Zhang, Xiaomin
2016-09-01
In this study, we propose a new graph-theoretical method to simulate guidewire paths inside the carotid artery. The minimum energy guidewire path can be obtained by applying the shortest path algorithm, such as Dijkstra's algorithm for graphs, based on the principle of the minimal total energy. Compared to previous results, experiments of three phantoms were validated, revealing that the first and second phantoms overlap completely between simulated and real guidewires. In addition, 95 % of the third phantom overlaps completely, and the remaining 5 % closely coincides. The results demonstrate that our method achieves 87 and 80 % improvements for the first and third phantoms under the same conditions, respectively. Furthermore, 91 % improvements were obtained for the second phantom under the condition with reduced graph construction complexity.
Energy Technology Data Exchange (ETDEWEB)
Ghosal, Dipak (University of California, Davis, CA); Mueller, Stephen Ng
2005-04-01
With multipath routing in mobile ad hoc networks (MANETs), a source can establish multiple routes to a destination for routing data. In MANETs, mulitpath routing can be used to provide route resilience, smaller end-to-end delay, and better load balancing. However, when the multiple paths are close together, transmissions of different paths may interfere with each other, causing degradation in performance. Besides interference, the physical diversity of paths also improves fault tolerance. We present a purely distributed multipath protocol based on the AODV-Multipath (AODVM) protocol called AODVM with Path Diversity (AODVM/PD) that finds multiple paths with a desired degree of correlation between paths specified as an input parameter to the algorithm. We demonstrate through detailed simulation analysis that multiple paths with low degree of correlation determined by AODVM/PD provides both smaller end-to-end delay than AODVM in networks with low mobility and better route resilience in the presence of correlated node failures.
Calculating Graph Algorithms for Dominance and Shortest Path
DEFF Research Database (Denmark)
Sergey, Ilya; Midtgaard, Jan; Clarke, Dave
2012-01-01
We calculate two iterative, polynomial-time graph algorithms from the literature: a dominance algorithm and an algorithm for the single-source shortest path problem. Both algorithms are calculated directly from the definition of the properties by fixed-point fusion of (1) a least fixed point expr...... of program calculation with common practice from the school of static program analysis, and build a novel view on iterative graph algorithms as instances of abstract interpretation...... expressing all finite paths through a directed graph and (2) Galois connections that capture dominance and path length. The approach illustrates that reasoning in the style of fixed-point calculus extends gracefully to the domain of graph algorithms. We thereby bridge common practice from the school......We calculate two iterative, polynomial-time graph algorithms from the literature: a dominance algorithm and an algorithm for the single-source shortest path problem. Both algorithms are calculated directly from the definition of the properties by fixed-point fusion of (1) a least fixed point...
Analysis of Brownian Particles for finding the shortest path in networks
Directory of Open Access Journals (Sweden)
huan yan qian
2013-07-01
Full Text Available In this paper, we propose a method to analyze the shortest path finding between two nodes in complex networks. In this method, we first find that single Brownian particle follows the shortest path between source node and destination node in the probability of where denotes the shortest path steps between two nodes. To be compared with single particle utilization, then we specially analyze the multiple particles. We compute the probability of particles’ taking the shortest path between and when particles starts simultaneously from the source and head to the destination as . It’s very clear that there must be particles taking the shortest path to arrive at the destination in the multiple particles environment. And with the number of increasing, the arriving probability first arise and then drop down rapidly until to zero. In the end, we make the experiments and confirm our theoretical analysis. Our results would provide valuable usage for some applications such as finding the optimal routing in wireless sensor networks.
Ayazi, S. M.; Mashhorroudi, M. F.; Ghorbani, M.
2014-10-01
Among the main issues in the theory of geometric grids on spatial information systems, is the problem of finding the shortest path routing between two points. In this paper tried to using the graph theory and A* algorithms in transport management, the optimal method to find the shortest path with shortest time condition to be reviewed. In order to construct a graph that consists of a network of pathways and modelling of physical and phasing area, the shortest path routes, elected with the use of the algorithm is modified A*.At of the proposed method node selection Examining angle nodes the desired destination node and the next node is done. The advantage of this method is that due to the elimination of some routes, time of route calculation is reduced.
Directory of Open Access Journals (Sweden)
S. M. Ayazi
2014-10-01
Full Text Available Among the main issues in the theory of geometric grids on spatial information systems, is the problem of finding the shortest path routing between two points. In this paper tried to using the graph theory and A* algorithms in transport management, the optimal method to find the shortest path with shortest time condition to be reviewed. In order to construct a graph that consists of a network of pathways and modelling of physical and phasing area, the shortest path routes, elected with the use of the algorithm is modified A*.At of the proposed method node selection Examining angle nodes the desired destination node and the next node is done. The advantage of this method is that due to the elimination of some routes, time of route calculation is reduced.
A new approach to shortest paths on networks based on the quantum bosonic mechanism
Jiang, Xin; Wang, Hailong; Tang, Shaoting; Ma, Lili; Zhang, Zhanli; Zheng, Zhiming
2011-01-01
This paper presents quantum bosonic shortest path searching (QBSPS), a natural, practical and highly heuristic physical algorithm for reasoning about the recognition of network structure via quantum dynamics. QBSPS is based on an Anderson-like itinerant bosonic system in which a boson's Green function is used as a navigation pointer for one to accurately approach the terminals. QBSPS is demonstrated by rigorous mathematical and physical proofs and plenty of simulations, showing how it can be used as a greedy routing to seek the shortest path between different locations. In methodology, it is an interesting and new algorithm rooted in the quantum mechanism other than combinatorics. In practice, for the all-pairs shortest-path problem in a random scale-free network with N vertices, QBSPS runs in O(μ(N) ln ln N) time. In application, we suggest that the corresponding experimental realizations are feasible by considering path searching in quantum optical communication networks; in this situation, the method performs a pure local search on networks without requiring the global structure that is necessary for current graph algorithms.
A Branch-and-Cut Algorithm for Elementary Shortest Path Problem with Resource Constraints
DEFF Research Database (Denmark)
Jepsen, Mads Kehlet; Petersen, Bjørn; Spoorendonk, Simon
The elementary shortest path with resource constraints are commonly solved with dynamic programming algorithms. We present a branch-and-cut algorithm for the undirected version. Two types of resources are discussed: A capacity and a fixed charge resource. The former is the subproblem of the capac...... of the capacitated vehicle routing problem and the latter is for the split delivery version....
Institute of Scientific and Technical Information of China (English)
邹益民; 高阳; 高碧悦
2013-01-01
Obstacle avoidance of the mobile robot is a hot research field of mobile robot control.Face with the given mobile robot obstacle avoidance problems,the path planning of shortest and fastest were explored.For shortest path planning,a simplified path mesh modal was established.Thus,a candidate solution was obtained by treating the scene as twodimensional map composed of nodes and edges and using classical Dijkstra algorithm to seek the shortest route.For fastest path planning,by analyzing the moving speed of the mobile robot along arc-shaped route,the strict mathematical relationship between the robot moving time with transition arc center was deduced based on geometric method,thereafter to obtain the optimal movement path by means of MATLAB optimization function.The proposed algorithm can be extended to solve similar robot obstacle avoidance problems.%移动机器人的避障问题是移动机器人控制领域的研究热点.针对给定的移动机器人避障问题,探讨了最短路径及最短时间路径的路径规划问题.对于最短路径问题,建立了简化的路径网格模型,将其抽象为由节点及边构成的两维图,再使用经典的Dijkstra算法获得可行的最短路径.对于最短时间路径问题,通过分析移动机器人弯道运行的速度曲线,基于几何方法得出了移动时间与过渡圆弧圆心之间严格的数学关系,此后借助MATLAB优化函数获得最佳的移动路径.算法可为类似机器人避障问题的解决提供借鉴.
K shortest paths in stochastic time-dependent networks
DEFF Research Database (Denmark)
Nielsen, Lars Relund; Pretolani, Daniele; Andersen, Kim Allan
2004-01-01
A substantial amount of research has been devoted to the shortest path problem in networks where travel times are stochastic or (deterministic and) time-dependent. More recently, a growing interest has been attracted by networks that are both stochastic and time-dependent. In these networks...
An optimal antenna motion generation using shortest path planning
Jeon, Moon-Jin; Kwon, Dong-Soo
2017-03-01
This paper considers an angular velocity minimization method for a satellite antenna. For high speed transmission of science data, a directional antenna with a two-axis gimbal is generally used. When a satellite passes over a ground station while pointing directly at it, the angular velocity of the satellite antenna can increase rapidly due to the gimbal kinematics. The high angular velocity could exceed the dynamic constraint of the antenna. Furthermore, micro vibration induced by high speed antenna rotation during an imaging operation might cause jitter, which can degrade the satellite image quality. To solve this problem, a minimum-velocity antenna motion generation method is proposed. Boundaries of the azimuth and elevation angles of the antenna within an effective beam width are derived using antenna geometry. A minimum-velocity azimuth profile and elevation profile within the boundaries are generated sequentially using a shortest path planning method. For fast and correct generation of the shortest path, a new algorithm called a string nailing algorithm is proposed. A numerical simulation shows that the antenna profile generated by the shortest path planning has a much lower angular velocity than the profiles generated by previous methods. The proposed string nailing algorithm also spends much less computation time than a search-based shortest path planning algorithm to generate almost the same antenna profiles.
ON THE ACCELERATION OF SHORTEST PATH CALCULATIONS IN TRANSPORTATION NETWORKS
Energy Technology Data Exchange (ETDEWEB)
BAKER, ZACHARY K. [Los Alamos National Laboratory; GOKHALE, MAYA B. [Los Alamos National Laboratory
2007-01-08
Shortest path algorithms are a key element of many graph problems. They are used in such applications as online direction finding and navigation, as well as modeling of traffic for large scale simulations of major metropolitan areas. As the shortest path algorithms are an execution bottleneck, it is beneficial to move their execution to parallel hardware such as Field-Programmable Gate Arrays (FPGAs). Hardware implementation is accomplished through the use of a small A core replicated on the order of 20 times on an FPGA device. The objective is to maximize the use of on-board random-access memory bandwidth through the use of multi-threaded latency tolerance. Each shortest path core is responsible for one shortest path calculation, and when it is finished it outputs its result and requests the next source from a queue. One of the innovations of this approach is the use of a small bubble sort core to produce the extract-min function. While bubble sort is not usually considered an appropriate algorithm for any non-trivial usage, it is appropriate in this case as it can produce a single minimum out of the list in O(n) cycles, whwere n is the number of elements in the vertext list. The cost of this min operation does not impact the running time of the architecture, because the queue depth for fetching the next set of edges from memory is roughly equivalent to the number of cores in the system. Additionally, this work provides a collection of simulation results that model the behavior of the node queue in hardware. The results show that a hardware queue, implementing a small bubble-type minimum function, need only be on the order of 16 elements to provide both correct and optimal paths. Because the graph database size is measured in the hundreds of megabytes, the Cray SRAM memory is insufficient. In addition to the A* cores, they have developed a memory management system allowing round-robin servicing of the nodes as well as virtual memory managed over the Hypertransport
The quickly switching routing algorithm based on multi-path in mobile Ad Hoc networks
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
This paper proposes a new on-demand multi-alternate-path algorithm, called quickly switching routing algorithm(QSRA). It switches failure routing to an alternate path as quickly as the network can. Like a nervure shape, algorithm QSRA shapes disjoint-alternate-path structure, but is not limited to. It also contains another structure that every primary node has several links to alternate paths. This structure has two advantages, the first one is that primary nodes can select one alternate path immediately when primary routing is failure without going back to source node to re-discover a new routing or choose an alternate path; the second is that it guarantees primary nodes can select another alternate path as quickly as possible once one of alternate paths fails. Strongpoint of algorithm QSRA is reducing frequency of routing re-discovering. Besides, the structure occupies fewer resources than other routing algorithms due to its distributed structure. Simulation shows that QSRA has higher packets received ratio and lower control packet overhead and lower end-to-end delay.
Optimized QoS Routing Algorithm
Institute of Scientific and Technical Information of China (English)
石明洪; 王思兵; 白英彩
2004-01-01
QoS routing is one of the key technologies for providing guaranteed service in IP networks. The paper focuses on the optimization problem for bandwidth constrained QoS routing, and proposes an optimal algorithm based on the global optimization of path bandwidth and hop counts. The main goal of the algorithm is to minimize the consumption of network resource, and at the same time to minimize the network congestion caused by irrational path selection. The simulation results show that our algorithm has lower call blocking rate and higher throughput than traditional algorithms.
The shortest path problem ninth DIMACS implementation challenge
Demetrescu, Camil; Johnson, David S
2009-01-01
Shortest path problems are among the most fundamental combinatorial optimization problems with many applications, both direct and as subroutines. They arise naturally in a remarkable number of real-world settings. A limited list includes transportation planning, network optimization, packet routing, image segmentation, speech recognition, document formatting, robotics, compilers, traffic information systems, and dataflow analysis. Shortest path algorithms have been studied since the 1950's and still remain an active area of research. This volume reports on the research carried out by participants during the Ninth DIMACS Implementation Challenge, which led to several improvements of the state of the art in shortest path algorithms. The infrastructure developed during the Challenge facilitated further research in the area, leading to substantial follow-up work as well as to better and more uniform experimental standards. The results of the Challenge included new cutting-edge techniques for emerging applications...
PACKET ROUTING ALGORITHM FOR LEO SATELLITE CONSTELLATION NETWORK
Institute of Scientific and Technical Information of China (English)
Wang Kaidong; Tian Bin; Yi Kechu
2005-01-01
A novel distributed packet routing algorithm for Low Earth Orbit (LEO) satellite networks based on spiderweb topology is presented. The algorithm gives the shortest path with very low computational complexity and without on-board routing tables, which is suitable and practical for on-board processing. Simulation results show its practicability and feasibility.
A branch-and-cut algorithm for the elementary shortest path problem with resource constraints
DEFF Research Database (Denmark)
Jepsen, Mads Kehlet; Petersen, Bjørn; Spoorendonk, Simon
The elementary shortest path with resource constraints have commonly been solved with dynamic programming algorithms. Assuming an undirected graph, we present a compact formulation of this problem and a branch-and-cut algorithm to solve it. Two types of resources are discussed: a capacity...... and a fixed charge resource. The former is the subproblem of the capacitated vehicle routing problem and the latter is from the split delivery version. Computational results are presented and compared to dynamic programming algorithms....
K shortest paths in stochastic time-dependent networks
DEFF Research Database (Denmark)
Nielsen, Lars Relund; Pretolani, Daniele; Andersen, Kim Allan
2004-01-01
, finding the a priori shortest path is NP-hard, while the best time-adaptive strategy can be found in polynomial time. In this paper, we propose a solution method for the a priori shortest path problem, and we show that it can be easily adapted to the ranking of the first K shortest paths. Moreover, we...
Ranking shortest paths in Stochastic time-denpendent networks
DEFF Research Database (Denmark)
Nielsen, Lars Relund; Andersen, Kim Allan; Pretolani, Daniele
, finding the a priori shortest path is NP-hard, while the best time-adaptive strategy can be found in polynomial time. In this paper, we propose a solution method for the a priori shortest path problem, and we show that it can be easily adapted to the ranking of the first K shortest paths. Moreover, we...
Institute of Scientific and Technical Information of China (English)
刘春年; 邓青菁
2014-01-01
The optimal path theory and practical study on the emergency decision information systems is an important branch and key research topics in the fields of disaster emergency informational engineering.The imped-ance function theory and Dijkstra algorithm into the research area of emergency decision information system optimal path is a research topic with ongoing concern and significant value.It is based on the reasoning and solving of the emergency decision information system optimal path,as well as with the Dijkstra algorithm for the overall technical approach and the impedance function theory for the technology extraction on the path weights of real-time sections, and also with the actual needs of emergency decision related as the center,this paper explored the theoretical tech-nical basis and problems countermeasures of the optimal routing mechanism and application of emergency decision information system and proposed a optimal path mathematical model which based on impedance function theory and Dijkstra algorithm and also calculated the model with an example to show the effectiveness of the algorithm.Under the complex traffic environment in disaster,this research idea can be more fully and effectively combined with spe-cific real-time road conditions to provide a retreat optimal path for affected people in disaster.%应急决策信息系统最优路径理论与实践研究是灾害应急信息化工程领域的重要分支和重点研究课题，将路阻函数理论与Dijkstra算法引入应急决策信息系统最优路径研究领域是一个持续引入关注并且具有显著价值的研究课题。围绕应急决策信息系统最优路径推理与求解，以Dijkstra算法为总体技术方法，以路阻函数理论为实时路段的路径权值提取技术基础，以应急决策相关主体的实际决策需求为中心，探索应急决策信息系统最优路径求解机制及其应用的理论技术基础及问题对策，提出了基于路阻函数
An improved Physarum polycephalum algorithm for the shortest path problem
National Research Council Canada - National Science Library
Zhang, Xiaoge; Wang, Qing; Adamatzky, Andrew; Chan, Felix T S; Mahadevan, Sankaran; Deng, Yong
2014-01-01
.... Acellular slime mould P. polycephalum is originally famous as a computing biological substrate due to its alleged ability to approximate shortest path from its inoculation site to a source of nutrients...
Distributed Power Control Routing Algorithm Based on Shortest Path Tree%基于最短路径树的分布式功率控制路由算法
Institute of Scientific and Technical Information of China (English)
陈友荣; 任条娟; 刘半藤; 葛灵晓
2012-01-01
When the nodes can not get the distance to neighbor nodes, to solve the problem that node consumes excessive energy,fails prematurely and leads to reduce the network lifetime,distributed power control routing algorithm based on shortest path tree( DPCRA_SPT) is proposed. Considering energy for transmitting data and neighbor nodes' residual energy, the new weight function and linear power attenuation model are introduced. Finally distributed asynchronous Bellman-Ford algorithm is used to construct the shortest path tree. All nodes transmit data along the shortest path tree to Sink node. Simulation results show that in the densely distributed wireless sensor networks, by adjusting the parameters, DPCRA_SPT can prolong network lifetime and remain energy consumption at a lower level. Under certain conditions,DPCRA_SPT outperforms Ratio_w_FTP,BFFTP,BFSAM and BFPAM algorithms.%当节点不能获知与邻居节点的距离时,为解决节点能量消耗过快而过早失效,从而减少网络生存时间的问题,提出基于最短路径树的分布式功率控制路由算法( DPCRA_SPT).该算法综合考虑网络中节点间传输数据的能耗和邻居节点的剩余能量,引入新的权值函数和功率线性衰减模型.运用分布式非同步Bellman-Ford算法构建最短路径树,所有节点沿着最短路径树将数据汇集到Sink节点.仿真结果表明:在密集分布的无线传感网中,通过调整参数,DPCRA_STT算法可以延长网络生存时间,将能耗保持在较低的水平.在一定的条件下,DPCRA_SPT算法比Ratio_w_FTP、BFFTP、BFSAM、BFPAM算法更优.
An Optimal Routing Algorithm in Service Customized 5G Networks
Directory of Open Access Journals (Sweden)
Haipeng Yao
2016-01-01
Full Text Available With the widespread use of Internet, the scale of mobile data traffic grows explosively, which makes 5G networks in cellular networks become a growing concern. Recently, the ideas related to future network, for example, Software Defined Networking (SDN, Content-Centric Networking (CCN, and Big Data, have drawn more and more attention. In this paper, we propose a service-customized 5G network architecture by introducing the ideas of separation between control plane and data plane, in-network caching, and Big Data processing and analysis to resolve the problems traditional cellular radio networks face. Moreover, we design an optimal routing algorithm for this architecture, which can minimize average response hops in the network. Simulation results reveal that, by introducing the cache, the network performance can be obviously improved in different network conditions compared to the scenario without a cache. In addition, we explore the change of cache hit rate and average response hops under different cache replacement policies, cache sizes, content popularity, and network topologies, respectively.
Li, Fajie
2011-01-01
This unique text/reference reviews algorithms for the exact or approximate solution of shortest-path problems, with a specific focus on a class of algorithms called rubberband algorithms. Discussing each concept and algorithm in depth, the book includes mathematical proofs for many of the given statements. Topics and features: provides theoretical and programming exercises at the end of each chapter; presents a thorough introduction to shortest paths in Euclidean geometry, and the class of algorithms called rubberband algorithms; discusses algorithms for calculating exact or approximate ESPs i
Securing a mobile adhoc network from routing attacks through the application of genetic algorithm
Nikhil, Kumar; Sharma, Pankaj
2012-01-01
In recent years, the static shortest path (SP) problem has been well addressed using intelligent optimization techniques, e.g., artificial neural networks, genetic algorithms (GAs), particle swarm optimization, etc. However, with the advancement in wireless communications, more and more mobile wireless networks appear, e.g., mobile networks [mobile ad hoc networks (MANETs)], wireless sensor networks, etc. One of the most important characteristics in mobile wireless networks is the topology dynamics, i.e., the network topology changes over time due to energy conservation or node mobility. Therefore, the SP routing problem in MANETs turns out to be a dynamic optimization problem. GA's are able to find, if not the shortest, at least an optimal path between source and destination in mobile ad-hoc network nodes. And we obtain the alternative path or backup path to avoid reroute discovery in the case of link failure or node failure.
Identification of Optimal Path in Power System Network Using Bellman Ford Algorithm
Directory of Open Access Journals (Sweden)
S. Hemalatha
2012-01-01
Full Text Available Power system network can undergo outages during which there may be a partial or total blackout in the system. In that condition, transmission of power through the optimal path is an important problem in the process of reconfiguration of power system components. For a given set of generation, load pair, there could be many possible paths to transmit the power. The optimal path needs to consider the shortest path (minimum losses, capacity of the transmission line, voltage stability, priority of loads, and power balance between the generation and demand. In this paper, the Bellman Ford Algorithm (BFA is applied to find out the optimal path and also the several alternative paths by considering all the constraints. In order to demonstrate the capability of BFA, it has been applied to a practical 230 kV network. This restorative path search guidance tool is quite efficient in finding the optimal and also the alternate paths for transmitting the power from a generating station to demand.
Differential Evolution Algorithm for Route Optimization Problems of Engineering Networks
Directory of Open Access Journals (Sweden)
O. G. Monahov
2015-01-01
Full Text Available The paper considers problems of structure optimization of engineering networks to provide a minimum total cost of engineering networks in construction and operation. The mathematical statement of the problem in terms of the hyper-network theory takes into account the interdependence of indicators of hyper-network elements, a layout area and a projected network. A digital model of terrain presents the placement area of engineering networks (a territory. In our case, it will be a weighted mesh (graph of primary network of dedicated vertices-consumers and a vertex-source for the utilities. The edges weights will be determined by the costs of construction and operation of the route between the given vertices of the network. The initial solution of the problem of minimizing the total cost will be using the minimum spanning tree, obtained on a weighted complete graph the vertices of which are defined by vertices-consumers and the vertexsource for the utilities, and the weights of edges are the distance between the vertices on the given weighted graph of the primary network. The work offers a method of differential evolution to solve the problem in hyper-network formulation that improves the initial solution by the mapping the edges of the secondary network in the primary network using additional Steiner points. As numerical experiments have shown, a differential evolution algorithm allows us to reduce the average total cost for a given engineering network compared to the initial solution by 5% - 15%, depending on the configuration, parameters, and layout area.
Effective usage of shortest paths promotes transportation efficiency on scale-free networks
Du, Wen-Bo; Wu, Zhi-Xi; Cai, Kai-Quan
2013-09-01
With rapid economic and social development, the problem of traffic congestion is getting more and more serious. Accordingly, network traffic models have attracted extensive attention. In this paper, we introduce a shortest-remaining-path-first queuing strategy into a network traffic model on Barabási-Albert scale-free networks under efficient routing protocol, where one packet’s delivery priority is related to its current distance to the destination. Compared with the traditional first-in-first-out queuing strategy, although the network capacity has no evident changes, some other indexes reflecting transportation efficiency are significantly improved in the congestion state. Extensive simulation results and discussions are carried out to explain the phenomena. Our work may be helpful for the designing of optimal networked-traffic systems.
The research of cooperative routing algorithm in mobile Ad hoc networks
Institute of Scientific and Technical Information of China (English)
CHEN Chao; ZHENG Bao-yu; ZHAO Xian-jing
2006-01-01
Cooperative routing technology can efficiently improve the performance of the network by initiatively selecting cooperative nodes to forward the data. In this article, cooperative routing algorithms are proposed and implemented based on three different criteria: optimal channel state, maximal remaining energy,and the shortest path. The simulation based on network simulation (NS) compares the performance of the proposed algorithms with non-cooperative destination-sequenced distance- vector (DSDV)protocol. The results reveal that cooperative algorithms outperform DSDV routing protocol with distinctive gains at the cost of sacrificing acceptable normalized network load.
A note on the pratical performance of the auction algorithm for the shortest path
DEFF Research Database (Denmark)
Larsen, Jesper
1998-01-01
The performance of the auction algorithm for the shortest path problem has previously been investigated in four papers. Here the results of a series of new experiments with the code from the two most recent papers are reported. Experiments clearly show that the auction algorithm is inferior...... to the state-of-the-art shortest path algorithms....
DYNAMIC K-MEANS ALGORITHM FOR OPTIMIZED ROUTING IN MOBILE AD HOC NETWORKS
Directory of Open Access Journals (Sweden)
Zahra Zandieh Shirazi
2016-04-01
Full Text Available In this paper, a dynamic K-means algorithm to improve the routing process in Mobile Ad-Hoc networks (MANETs is presented. Mobile ad-hoc networks are a collocation of mobile wireless nodes that can operate without using focal access points, pre-existing infrastructures, or a centralized management point. In MANETs, the quick motion of nodes modifies the topology of network. This feature of MANETS is lead to various problems in the routing process such as increase of the overhead massages and inefficient routing between nodes of network. A large variety of clustering methods have been developed for establishing an efficient routing process in MANETs. Routing is one of the crucial topics which are having significant impact on MANETs performance. The K-means algorithm is one of the effective clustering methods aimed to reduce routing difficulties related to bandwidth, throughput and power consumption. This paper proposed a new K-means clustering algorithm to find out optimal path from source node to destinations node in MANETs. The main goal of proposed approach which is called the dynamic K-means clustering methods is to solve the limitation of basic K-means method like permanent cluster head and fixed cluster members. The experimental results demonstrate that using dynamic K-means scheme enhance the performance of routing process in Mobile ad-hoc networks.
Shortest Paths in Microseconds
Agarwal, Rachit; Godfrey, P Brighten; Zhao, Ben Y
2013-01-01
Computing shortest paths is a fundamental primitive for several social network applications including socially-sensitive ranking, location-aware search, social auctions and social network privacy. Since these applications compute paths in response to a user query, the goal is to minimize latency while maintaining feasible memory requirements. We present ASAP, a system that achieves this goal by exploiting the structure of social networks. ASAP preprocesses a given network to compute and store a partial shortest path tree (PSPT) for each node. The PSPTs have the property that for any two nodes, each edge along the shortest path is with high probability contained in the PSPT of at least one of the nodes. We show that the structure of social networks enable the PSPT of each node to be an extremely small fraction of the entire network; hence, PSPTs can be stored efficiently and each shortest path can be computed extremely quickly. For a real network with 5 million nodes and 69 million edges, ASAP computes a short...
Competition for shortest paths on sparse graphs.
Yeung, Chi Ho; Saad, David
2012-05-18
Optimal paths connecting randomly selected network nodes and fixed routers are studied analytically in the presence of a nonlinear overlap cost that penalizes congestion. Routing becomes more difficult as the number of selected nodes increases and exhibits ergodicity breaking in the case of multiple routers. The ground state of such systems reveals nonmonotonic complex behaviors in average path length and algorithmic convergence, depending on the network topology, and densities of communicating nodes and routers. A distributed linearly scalable routing algorithm is also devised.
Solving the constrained shortest path problem using random search strategy
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
In this paper, we propose an improved walk search strategy to solve the constrained shortest path problem. The proposed search strategy is a local search algorithm which explores a network by walker navigating through the network. In order to analyze and evaluate the proposed search strategy, we present the results of three computational studies in which the proposed search algorithm is tested. Moreover, we compare the proposed algorithm with the ant colony algorithm and k shortest paths algorithm. The analysis and comparison results demonstrate that the proposed algorithm is an effective tool for solving the constrained shortest path problem. It can not only be used to solve the optimization problem on a larger network, but also is superior to the ant colony algorithm in terms of the solution time and optimal paths.
Planeta, David S
2007-01-01
In this paper I present general outlook on questions relevant to the basic graph algorithms; Finding the Shortest Path with Positive Weights and Minimum Spanning Tree. I will show so far known solution set of basic graph problems and present my own. My solutions to graph problems are characterized by their linear worst-case time complexity. It should be noticed that the algorithms which compute the Shortest Path and Minimum Spanning Tree problems not only analyze the weight of arcs (which is the main and often the only criterion of solution hitherto known algorithms) but also in case of identical path weights they select this path which walks through as few vertices as possible. I have presented algorithms which use priority queue based on multilevel prefix tree -- PTrie. PTrie is a clever combination of the idea of prefix tree -- Trie, the structure of logarithmic time complexity for insert and remove operations, doubly linked list and queues. In C++ I will implement linear worst-case time algorithm computin...
Uncertainty-Based Map Matching: The Space-Time Prism and k-Shortest Path Algorithm
Directory of Open Access Journals (Sweden)
Bart Kuijpers
2016-11-01
Full Text Available Location-aware devices can be used to record the positions of moving objects for further spatio-temporal data analysis. For instance, we can analyze the routes followed by a person or a group of people, to discover hidden patterns in trajectory data. Typically, the positions of moving objects are registered by GPS devices, and most of the time, the recorded positions do not match the road actually followed by the object carrying the device, due to different sources of errors. Thus, matching the moving object’s actual position to a location on a digital map is required. The problem of matching GPS-recorded positions to a road network is called map matching (MM. Although many algorithms have been proposed to solve this problem, few of them consider the uncertainty caused by the absence of information about the moving object’s position in-between consecutive recorded locations. In this paper, we study the relationship between map matching and uncertainty, and we propose a novel MM algorithm that uses space-time prisms in combination with weighted k-shortest path algorithms. We applied our algorithm to real-world cases and to computer-generated trajectory samples with a variety of properties. We compare our results against a number of well-known algorithms that we have also implemented and show that it outperforms existing algorithms, allowing us to obtain better matches, with a negligible loss in performance. In addition, we propose a novel accuracy measure that allows a better comparison between different MM algorithms. We applied this novel measure to compare our algorithm against existing algorithms.
Fully dynamic output bounded single source shortest path problem
Energy Technology Data Exchange (ETDEWEB)
Frigioni, D. [Universita di L`Aquila, Coppito (Italy); Marchetti-Spaccamela, A.; Nanni, U. [Universita di Roma (Italy)
1996-12-31
We consider the problem of maintaining the distances and the shortest paths from a single source in either a directed or an undirected graph with positive real edge weights, handling insertions, deletions and cost updates of edges. We propose fully dynamic algorithms with optimal space requirements and query time. The cost of update operations depends on the class of the considered graph and on the number of vertices that, due to an edge modification, either change their distance from the source or change their parent in the shortest path tree. In the case of graphs with bounded genus (including planar graphs), bounded degree graphs, bounded treewidth graphs and O-near-planar graphs with bounded {beta}, the update procedures require O(log n) amortized time per vertex update, while for general graphs with n vertices and m edges they require O({radical}m log n) amortized time per vertex update. The solution is based on a dynamization of Dijkstra`s algorithm and requires simple data structures that are suitable for a practical and straightforward implementation.
A Multiobjective Optimization Algorithm for QoS-Aware Path Selection in DiffServ and MPLS Networks
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
A multiobjective quality of service (QoS) routing algorithm was proposed and used as the QoS-aware path selection approach in differentiated services and multi-protocol label switching (DiffServ-MPLS) networks. It simultaneously optimizes multiple QoS objectives by a genetic algorithm in conjunction with concept of Pareto dominance. The simulation demonstrates that the proposed algorithm is capable of discovering a set of QoS-based near optimal paths within in a few iterations. In addition, the simulation results also show the scalability of the algorithm with increasing number of network nodes.
Directory of Open Access Journals (Sweden)
Yifan Hu
2012-01-01
Full Text Available The fault-tolerant routing problem is important consideration in the design of heterogeneous wireless sensor networks (H-WSNs applications, and has recently been attracting growing research interests. In order to maintain k disjoint communication paths from source sensors to the macronodes, we present a hybrid routing scheme and model, in which multiple paths are calculated and maintained in advance, and alternate paths are created once the previous routing is broken. Then, we propose an immune cooperative particle swarm optimization algorithm (ICPSOA in the model to provide the fast routing recovery and reconstruct the network topology for path failure in H-WSNs. In the ICPSOA, mutation direction of the particle is determined by multi-swarm evolution equation, and its diversity is improved by immune mechanism, which can enhance the capacity of global search and improve the converging rate of the algorithm. Then we validate this theoretical model with simulation results. The results indicate that the ICPSOA-based fault-tolerant routing protocol outperforms several other protocols due to its capability of fast routing recovery mechanism, reliable communications, and prolonging the lifetime of WSNs.
Directory of Open Access Journals (Sweden)
Siddhartha Sankar Biswas
2014-01-01
Full Text Available The networks of the present day communication systems, be it a public road transportation system or a MANET or an Adhoc Network, frequently face a lot of uncertainties in particular regarding traffic jam, flood or water logging or PWD maintenance work (in case of public road network, attack or damage from internal or external agents, sudden failure of one or few nodes. Consequently, at a real instant of time, the existing links/arcs of a given network (graph are not always in their original/excellent condition physically or logically, rather in a weaker condition, or even sometimes disabled or blocked temporarily and waiting for maintenance/repair; and hence ultimately causing delay in communication or transportation. We do not take any special consideration if few of the links be in a better condition at the real time of communication, we consider only such cases where few links are in inferior condition (partially or fully damaged. The classical Dijkstra’s algorithm to find the shortest path in graphs is applicable only if we assume that all the links of the concerned graph are available at their original (ideal condition at that real time of communication, but at real time scenario it is not the case. Consequently, the mathematically calculated shortest path extracted by using Dijkstra’s algorithm may become costlier (even in-feasible in some cases in terms of time and/or in terms of other overhead costs; whereas some other path may be the most efficient or most optimal. Many real life situations of communication network or transportation network cannot be modeled into graphs, but can be well modeled into multigraphs because of the scope of dealing with multiple links (or arcs connecting a pair of nodes. The classical Dijkstra’s algorithm to find the shortest path in graphs is not applicable to multigraphs. In this study the authors make a refinement of the classical Dijkstra’s algorithm to make it applicable to directed multigraphs
Directory of Open Access Journals (Sweden)
David S. Hardin
2013-04-01
Full Text Available As Graphics Processing Units (GPUs have gained in capability and GPU development environments have matured, developers are increasingly turning to the GPU to off-load the main host CPU of numerically-intensive, parallelizable computations. Modern GPUs feature hundreds of cores, and offer programming niceties such as double-precision floating point, and even limited recursion. This shift from CPU to GPU, however, raises the question: how do we know that these new GPU-based algorithms are correct? In order to explore this new verification frontier, we formalized a parallelizable all-pairs shortest path (APSP algorithm for weighted graphs, originally coded in NVIDIA's CUDA language, in ACL2. The ACL2 specification is written using a single-threaded object (stobj and tail recursion, as the stobj/tail recursion combination yields the most straightforward translation from imperative programming languages, as well as efficient, scalable executable specifications within ACL2 itself. The ACL2 version of the APSP algorithm can process millions of vertices and edges with little to no garbage generation, and executes at one-sixth the speed of a host-based version of APSP coded in C – a very respectable result for a theorem prover. In addition to formalizing the APSP algorithm (which uses Dijkstra's shortest path algorithm at its core, we have also provided capability that the original APSP code lacked, namely shortest path recovery. Path recovery is accomplished using a secondary ACL2 stobj implementing a LIFO stack, which is proven correct. To conclude the experiment, we ported the ACL2 version of the APSP kernels back to C, resulting in a less than 5% slowdown, and also performed a partial back-port to CUDA, which, surprisingly, yielded a slight performance increase.
Reliable Mobile Ad-Hoc Network Routing Using Firefly Algorithm
Directory of Open Access Journals (Sweden)
D Jinil Persis
2016-05-01
Full Text Available Routing in Mobile Ad-hoc NETwork (MANET is a contemporary graph problem that is solved using various shortest path search techniques. The routing algorithms employed in modern routers use deterministic algorithms that extract an exact non-dominated set of solutions from the search space. The search efficiency of these algorithms is found to have an exponential time complexity in the worst case. Moreover this problem is a multi-objective optimization problem in nature for MANET and it is required to consider changing topology layout. This study attempts to employ a formulation incorporating objectives viz., delay, hop-distance, load, cost and reliability that has significant impact on network performance. Simulation with different random topologies has been carried out to illustrate the implementation of an exhaustive search algorithm and it is observed that the algorithm could handle small-scale networks limited to 15 nodes. A random search meta-heuristic that adopts the nature of firefly swarm has been proposed for larger networks to yield an approximated non-dominated path set. Firefly Algorithm is found to perform better than the exact algorithm in terms of scalability and computational time.
A symbolic shortest path algorithm for computing subgame-perfect Nash equilibria
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Góngora Pedro A.
2015-09-01
Full Text Available Consider games where players wish to minimize the cost to reach some state. A subgame-perfect Nash equilibrium can be regarded as a collection of optimal paths on such games. Similarly, the well-known state-labeling algorithm used in model checking can be viewed as computing optimal paths on a Kripke structure, where each path has a minimum number of transitions. We exploit these similarities in a common generalization of extensive games and Kripke structures that we name “graph games”. By extending the Bellman-Ford algorithm for computing shortest paths, we obtain a model-checking algorithm for graph games with respect to formulas in an appropriate logic. Hence, when given a certain formula, our model-checking algorithm computes the subgame-perfect Nash equilibrium (as opposed to simply determining whether or not a given collection of paths is a Nash equilibrium. Next, we develop a symbolic version of our model checker allowing us to handle larger graph games. We illustrate our formalism on the critical-path method as well as games with perfect information. Finally, we report on the execution time of benchmarks of an implementation of our algorithms
Smoothed analysis of the successive shortest path algorithm
Cornelissen, Kamiel; Brunsch, Tobias; Hoeksma, R.P.; Hurink, Johann L.; Manthey, Bodo; Röglin, Heiko
2013-01-01
The minimum-cost flow problem is a classic problem in combinatorial optimization with various applications. Several pseudo-polynomial, polynomial, and strongly polynomial algorithms have been developed in the past decades, and it seems that both the problem and the algorithms are well understood.
Institute of Scientific and Technical Information of China (English)
邢移单
2015-01-01
The demand for decrease of network energy consumption and improvement of energy efficiency makes the green IP over WDM network a research hotspot in the area of optical communication network. For the purpose to reduce the network energy consumption and ensure the network performance for the traf-fic load, the hierarchical integrated auxiliary graph model is established, and the saving energy multiple jump grooming ( OMJG) routing algorithm for the optical layer node optimization configuration of IP over WDM network designed and simulated, Simulation and comparison with the shortest path first algorithm ( Dijkstra) inidcate that the OMJG algorithm is clearly superior to the traditional Dijkstra algorithm in total energy consumption and service request blocking probability of the netwok.%降低网络能耗和提高能量利用率的需求,使绿色IP over WDM网络成为光网络领域的研究热点。针对流量业务,以降低网络能耗和保证网络性能为优化目标,建立了分层集成辅助图模型,根据多跳疏导机制设计了IP over WDM 网络光层节点优化配置下的节能多跳疏导( Optical Multiple Jump Grooming,OMJG)路由算法,进行了仿真,并与最短路径优先算法( Dijkstra)进行了比较。结果表明：在网络总能耗和业务请求阻塞率方面,设计的OMJG算法均优于传统的Dijkstra算法。
Efficient algorithms for the reverse shortest path problem on trees under the hamming distance
Directory of Open Access Journals (Sweden)
Tayyebi Javad
2017-01-01
Full Text Available Given a network G(V,A,c and a collection of origin-destination pairs with prescribed values, the reverse shortest path problem is to modify the arc length vector c as little as possible under some bound constraints such that the shortest distance between each origin-destination pair is upper bounded by the corresponding prescribed value. It is known that the reverse shortest path problem is NP-hard even on trees when the arc length modifications are measured by the weighted sum-type Hamming distance. In this paper, we consider two special cases of this problem which are polynomially solvable. The first is the case with uniform lengths. It is shown that this case transforms to a minimum cost flow problem on an auxiliary network. An efficient algorithm is also proposed for solving this case under the unit sum-type Hamming distance. The second case considered is the problem without bound constraints. It is shown that this case is reduced to a minimum cut problem on a tree-like network. Therefore, both cases studied can be solved in strongly polynomial time.
A Practical Parallel Algorithm for All-Pair Shortest Path Based on Pipelining
Institute of Scientific and Technical Information of China (English)
Hua Wang; Ling Tian; Chun-Hua Jiang
2008-01-01
On the basis of Floyd algorithm with theextended path matrix, a parallel algorithm whichresolves all-pair shortest path (APSP) problem oncluster environment is analyzed and designed.Meanwhile, the parallel APSP pipelining algorithmmakes full use of overlapping technique betweencomputation and communication. Compared withbroadcast operation, the parallel algorithm reducescommunication cost. This algorithm has beenimplemented on MPI on PC-cluster. The theoreticalanalysis and experimental results show that the parallelalgorithm is an efficient and scalable algorithm.
Congestion control and routing over satellite networks
Cao, Jinhua
) method and then develop a novel on-demand routing system named Cross Entropy Accelerated Ant Routing System (CEAARS) for regular constellation LEO satellite networks. By implementing simulations on an Iridium-like satellite network, we compare the proposed CEAARS algorithm with the two approaches to adaptive routing protocols on the Internet: distance-vector (DV) and link-state (LS), as well as with the original Cross Entropy Ant Routing System (CEARS). DV algorithms are based on distributed Bellman Ford algorithm, and LS algorithms are implementation of Dijkstras single source shortest path. The results show that CEAARS not only remarkably improves the convergence speed of achieving optimal or suboptimal paths, but also reduces the number of overhead ants (management packets).
Directory of Open Access Journals (Sweden)
J R Managbanag
Full Text Available BACKGROUND: Identification of genes that modulate longevity is a major focus of aging-related research and an area of intense public interest. In addition to facilitating an improved understanding of the basic mechanisms of aging, such genes represent potential targets for therapeutic intervention in multiple age-associated diseases, including cancer, heart disease, diabetes, and neurodegenerative disorders. To date, however, targeted efforts at identifying longevity-associated genes have been limited by a lack of predictive power, and useful algorithms for candidate gene-identification have also been lacking. METHODOLOGY/PRINCIPAL FINDINGS: We have utilized a shortest-path network analysis to identify novel genes that modulate longevity in Saccharomyces cerevisiae. Based on a set of previously reported genes associated with increased life span, we applied a shortest-path network algorithm to a pre-existing protein-protein interaction dataset in order to construct a shortest-path longevity network. To validate this network, the replicative aging potential of 88 single-gene deletion strains corresponding to predicted components of the shortest-path longevity network was determined. Here we report that the single-gene deletion strains identified by our shortest-path longevity analysis are significantly enriched for mutations conferring either increased or decreased replicative life span, relative to a randomly selected set of 564 single-gene deletion strains or to the current data set available for the entire haploid deletion collection. Further, we report the identification of previously unknown longevity genes, several of which function in a conserved longevity pathway believed to mediate life span extension in response to dietary restriction. CONCLUSIONS/SIGNIFICANCE: This work demonstrates that shortest-path network analysis is a useful approach toward identifying genetic determinants of longevity and represents the first application of
Output-threshold coupled neural network for solving the shortest path problems
Institute of Scientific and Technical Information of China (English)
ZHANG Junying; WANG Defeng; SHI Meihong; WANG Joseph Yue
2004-01-01
This paper presents a coupled neural network, called output-threshold coupled neural network (OTCNN), which can mimic the autowaves in the present pulsed coupled neural networks (PCNNs), by the construction of mutual coupling between neuron outputs and the threshold of a neuron. Based on its autowaves, this paper presents a method for finding the shortest path in shortest time with OTCNNs. The method presented here features much fewer neurons needed, simplicity of the structure of the neurons and the networks, and large scale of parallel computation. It is shown that OTCNN is very effective in finding the shortest paths from a single start node to multiple destination nodes for asymmetric weighted graph, with a number of iterations proportional only to the length of the shortest paths, but independent of the complexity of the graph and the total number of existing paths in the graph. Finally, examples for finding the shortest path are presented.
Directory of Open Access Journals (Sweden)
Matheswaran Saravanan
2014-01-01
Full Text Available Wireless sensor network (WSN consists of sensor nodes that need energy efficient routing techniques as they have limited battery power, computing, and storage resources. WSN routing protocols should enable reliable multihop communication with energy constraints. Clustering is an effective way to reduce overheads and when this is aided by effective resource allocation, it results in reduced energy consumption. In this work, a novel hybrid evolutionary algorithm called Bee Algorithm-Simulated Annealing Weighted Minimal Spanning Tree (BASA-WMST routing is proposed in which randomly deployed sensor nodes are split into the best possible number of independent clusters with cluster head and optimal route. The former gathers data from sensors belonging to the cluster, forwarding them to the sink. The shortest intrapath selection for the cluster is selected using Weighted Minimum Spanning Tree (WMST. The proposed algorithm computes the distance-based Minimum Spanning Tree (MST of the weighted graph for the multihop network. The weights are dynamically changed based on the energy level of each sensor during route selection and optimized using the proposed bee algorithm simulated annealing algorithm.
Leapfrog: Optimal opportunistic Routing in Probabilistically Contacted Delay Tolerant Networks
Institute of Scientific and Technical Information of China (English)
Ming-Jun Xiao; Liu-Sheng Huang; Qun-Feng Dong; An Liu; Zhen-Guo Yang
2009-01-01
Delay tolerant networks (DTNs)experience frequent and long lasting network disconnection due to various reasons such as mobility.power management.and scheduling.One primary concern in DTNs is to route messages to keep the end-to-end delivery delay as low as possible.In this paper,we study the single-copy message routing problem and propose an optimal opportunistic routing strategy--Leapfrog Routing--for probabilistically contacted DTNs where nodes encounter or contact in some fixed probabilities.We deduce the iterative computation formulate of minimum expected opportunistic delivery delay from each node to the destination and discover that under the optimal opportunistic routing strategy,messages would be delivered from high-delay node to low-delay node in the leapfrog manner.Rigorous theoretical analysis shows that such a routing strategy is exactly the optimal among all possible ones.Moreover,we apply the idea of Reverse Dijkstra algorithm to design an algorithm.When a destination iS given,this algorithm can determine for each node the routing selection function under the Leapfrog Routing strategy.The computation overhead of this algorithm is only O(n~2) where n is the number of nodes in the network.In addition,through extensive simulations based on real DTN traces,we demonstrate that our algorithm can significantly outperform the previous ones.
Physarum Can Compute Shortest Paths
Bonifaci, Vincenzo; Varma, Girish
2011-01-01
A mathematical model has been proposed by biologists to describe the feedback mechanism used by the Physarum Polycephalum slime mold to adapt its tubular channels while foraging two food sources $s_0$ and $s_1$. We give a proof of the fact that, under this model, the mass of the mold will eventually converge to the shortest $s_0$-$s_1$ path of the network that the mold lies on, independently of the structure of the network or of the initial mass distribution. This matches the experimental observations by the biologists and can be seen as an example of a "natural algorithm", that is, an algorithm developed by evolution over millions of years.
DEFF Research Database (Denmark)
Brodal, G.S.; Fagerberg, R.; Meyer, U.;
2004-01-01
We present improved cache-oblivious data structures and algorithms for breadth-first search and the single-source shortest path problem on undirected graphs with non-negative edge weights. Our results removes the performance gap between the currently best cache-aware algorithms for these problems...... and their cache-oblivious counterparts. Our shortest-path algorithm relies on a new data structure, called bucket heap, which is the first cache-oblivious priority queue to efficiently support a weak DecreaseKey operation....
Delay-Constrained Multicast Routing Algorithm Based on Average Distance Heuristic
Ling, Zhou; Yu-xi, Zhu; 10.5121/ijcnc.2010.2212
2010-01-01
Multicast is the ability of a communication network to accept a single message from an application and to deliver copies of the message to multiple recipients at different location. With the development of Internet, Multicast is widely applied in all kinds of multimedia real-time application: distributed multimedia systems, collaborative computing, video-conferencing, distance education, etc. In order to construct a delay-constrained multicast routing tree, average distance heuristic (ADH) algorithm is analyzed firstly. Then a delay-constrained algorithm called DCADH (delay-constrained average distance heuristic) is presented. By using ADH a least cost multicast routing tree can be constructed; if the path delay can't meet the delay upper bound, a shortest delay path which is computed by Dijkstra algorithm will be merged into the existing multicast routing tree to meet the delay upper bound. Simulation experiments show that DCADH has a good performance in achieving a low-cost multicast routing tree.
Hierarchical Route Optimization By Using Memetic Algorithm In A Mobile Networks
Directory of Open Access Journals (Sweden)
K .K. Gautam
2011-02-01
Full Text Available The networks Mobility (NEMO Protocol is a way of managing the mobility of an entire network, and mobile internet protocol is the basic solution for networks Mobility. A hierarchical route optimization system for mobile network is proposed to solve management of hierarchical route optimization problems. In present paper we study hierarchical Route Optimization scheme using memetic algorithm(HROSMA The concept of optimization- finding the extreme of a function that maps candidate ‘solution’ to scalar values of ‘quality’ – is an extremely general and useful idea. For solving this problem, we use a few salient adaptations, and we also extend HROSMA perform routing between the mobile networks.
A Practical Parallel Algorithm for All-Pair Shortest Path Based on Pipelining
Institute of Scientific and Technical Information of China (English)
Hua Wang; Ling Tian; Chun-Hua Jiang
2008-01-01
On the basis of Floyd algorithm with the extended path matrix, a parallel algorithm which resolves all-pair shortest path (APSP) problem on cluster environment is analyzed and designed. Meanwhile, the parallel APSP pipelining algorithm makes full use of overlapping technique between computation and communication. Compared with broadcast operation, the parallel algorithm reduces communication cost. This algorithm has been implemented on MPI on PC-cluster. The theoretical analysis and experimental results show that the parallel algorithm is an efficient and scalable algorithm.
Shen, Yi; Ren, Gang; Liu, Yang
2016-06-01
In this paper, we propose a biased-shortest path method with minimal congestion. In the method, we use linear-prediction to estimate the queue length of nodes, and propose a dynamic accepting probability function for nodes to decide whether accept or reject the incoming packets. The dynamic accepting probability function is based on the idea of homogeneous network flow and is developed to enable nodes to coordinate their queue length to avoid congestion. A path strategy incorporated with the linear-prediction of the queue length and the dynamic accepting probability function of nodes is designed to allow packets to be automatically delivered on un-congested paths with short traveling time. Our method has the advantage of low computation cost because the optimal paths are dynamically self-organized by nodes in the delivering process of packets with local traffic information. We compare our method with the existing methods such as the efficient path method (EPS) and the optimal path method (OPS) on the BA scale-free networks and a real example. The numerical computations show that our method performs best for low network load and has minimum run time due to its low computational cost and local routing scheme.
A self-organizing shortest path finding strategy on complex networks
Institute of Scientific and Technical Information of China (English)
Shen Yi; Pei Wen-Jiang; Wang Kai; Wang Shao-Ping
2009-01-01
The shortcomings of traditional methods to find the shortest path are revealed,and a strategy of finding the selforganizing shortest path based on thermal flux diffusion on complex networks is presented. In our method,the shortest paths between the source node and the other nodes are found to be self-organized by comparing node temperatures. The computation complexity of the method scales linearly with the number of edges on underlying networks. The effects of the method on several networks,including a regular network proposed by Ravasz and Barabási which is called the RB network,a real network,a random network proposed by Ravasz and Barabási which is called the ER network and a scale-free network,are also demonstrated. Analytic and simulation results show that the method has a higher accuracy and lower computational complexity than the conventional methods.
Transport optimization on complex networks
Danila, Bogdan; Marsh, John A; Bassler, Kevin E
2007-01-01
We present a comparative study of the application of a recently introduced heuristic algorithm to the optimization of transport on three major types of complex networks. The algorithm balances network traffic iteratively by minimizing the maximum node betweenness with as little path lengthening as possible. We show that by using this optimal routing, a network can sustain significantly higher traffic without jamming than in the case of shortest path routing. A formula is proved that allows quick computation of the average number of hops along the path and of the average travel times once the betweennesses of the nodes are computed. Using this formula, we show that routing optimization preserves the small-world character exhibited by networks under shortest path routing, and that it significantly reduces the average travel time on congested networks with only a negligible increase in the average travel time at low loads. Finally, we study the correlation between the weights of the links in the case of optimal ...
Research of Dijkstra algorithm in protein sequence alignment%Dijkstra算法在蛋白质序列比对中的研究
Institute of Scientific and Technical Information of China (English)
祁长红; 郁芸; 韩新焕
2012-01-01
A sequence alignment algorithm based on Dijkstra algorithm is put forward, which is mainly used to seek the shortest path while the problem of sequence alignment can be transformed into a problem to look for the shortest path in directed acyclic graph. For a small amount of sequences, Dijkstra algorithm is easier to seek the optimal solution. For multiple sequences alignment, the shortest path seeked in the Af-dimensional space can be obtained in the two-dimensional space. It can be proved that the problem is greatly simplified and the sub-optimal solution can be obtained.%提出一种基于Dijkstra算法的序列比对方法,该算法主要用于求最短路径,而序列比对可以转化为在有向无环图中寻找最短路径问题.对于少量序列比对,使用该算法可以求出最优解.对于多序列比对,可将在N维空间求解最短路径问题转化为在二维空间求解最短路径.该算法可以简化问题复杂度,能求得相对最优解.
A Bio-Inspired Method for the Constrained Shortest Path Problem
Directory of Open Access Journals (Sweden)
Hongping Wang
2014-01-01
optimization, crew scheduling, network routing and so on. It is an open issue since it is a NP-hard problem. In this paper, we propose an innovative method which is based on the internal mechanism of the adaptive amoeba algorithm. The proposed method is divided into two parts. In the first part, we employ the original amoeba algorithm to solve the shortest path problem in directed networks. In the second part, we combine the Physarum algorithm with a bio-inspired rule to deal with the CSP. Finally, by comparing the results with other method using an examples in DCLC problem, we demonstrate the accuracy of the proposed method.
Multi- Path Routing and Resource Allocation in Active Network
Institute of Scientific and Technical Information of China (English)
XU Wu-ping; YAN Pu-liu; WU Ming
2005-01-01
An algorithm of traffic distribution called active multi-path routing (AMR) in active network is proposed.AMR adopts multi-path routing and applies nonlinear optimize approximate method to distribute network traffic amongmultiple paths. It is combined to bandwidth resource allocation and the congestion restraint mechanism to avoid congestion happening and worsen. So network performance can be improved greatly. The frame of AMR includes adaptive trafficallocation model, the conception of supply bandwidth and its'allocation model, the principle of congestion restraint and its'model, and the implement of AMR based on multi-agents system in active network. Through simulations, AMR has distinct effects on network performance. The results show AMR is a valid traffic regulation algorithm.
Contour polygonal approximation using shortest path in networks
Backes, André Ricardo; Bruno, Odemir Martinez
2013-01-01
Contour polygonal approximation is a simplified representation of a contour by line segments, so that the main characteristics of the contour remain in a small number of line segments. This paper presents a novel method for polygonal approximation based on the Complex Networks theory. We convert each point of the contour into a vertex, so that we model a regular network. Then we transform this network into a Small-World Complex Network by applying some transformations over its edges. By analyzing of network properties, especially the geodesic path, we compute the polygonal approximation. The paper presents the main characteristics of the method, as well as its functionality. We evaluate the proposed method using benchmark contours, and compare its results with other polygonal approximation methods.
Protein-fold recognition using an improved single-source K diverse shortest paths algorithm.
Lhota, John; Xie, Lei
2016-04-01
Protein structure prediction, when construed as a fold recognition problem, is one of the most important applications of similarity search in bioinformatics. A new protein-fold recognition method is reported which combines a single-source K diverse shortest path (SSKDSP) algorithm with Enrichment of Network Topological Similarity (ENTS) algorithm to search a graphic feature space generated using sequence similarity and structural similarity metrics. A modified, more efficient SSKDSP algorithm is developed to improve the performance of graph searching. The new implementation of the SSKDSP algorithm empirically requires 82% less memory and 61% less time than the current implementation, allowing for the analysis of larger, denser graphs. Furthermore, the statistical significance of fold ranking generated from SSKDSP is assessed using ENTS. The reported ENTS-SSKDSP algorithm outperforms original ENTS that uses random walk with restart for the graph search as well as other state-of-the-art protein structure prediction algorithms HHSearch and Sparks-X, as evaluated by a benchmark of 600 query proteins. The reported methods may easily be extended to other similarity search problems in bioinformatics and chemoinformatics. The SSKDSP software is available at http://compsci.hunter.cuny.edu/~leixie/sskdsp.html.
External Memory Algorithms for Diameter and All-Pair Shortest-Paths on Sparse Graphs
DEFF Research Database (Denmark)
Arge, Lars; Meyer, Ulrich; Toma, Laura
2004-01-01
We present several new external-memory algorithms for finding all-pairs shortest paths in a V -node, Eedge undirected graph. For all-pairs shortest paths and diameter in unweighted undirected graphs we present cache-oblivious algorithms with O(V · E B logM B E B) I/Os, where B is the block......-size and M is the size of internal memory. For weighted undirected graphs we present a cache-aware APSP algorithm that performs O(V · ( V E B +E B log E B )) I/Os. We also present efficient cacheaware algorithms that find paths between all pairs of vertices in an unweighted graph with lengths within a small...... additive constant of the shortest path length. All of our results improve earlier results known for these problems. For approximate APSP we provide the first nontrivial results. Our diameter result uses O(V + E) extra space, and all of our other algorithms use O(V 2) space....
External Memory Algorithms for Diameter and All-Pair Shortest-Paths on Sparse Graphs
DEFF Research Database (Denmark)
Arge, Lars; Meyer, Ulrich; Toma, Laura
2004-01-01
We present several new external-memory algorithms for finding all-pairs shortest paths in a V -node, Eedge undirected graph. For all-pairs shortest paths and diameter in unweighted undirected graphs we present cache-oblivious algorithms with O(V · E B logM B E B) I/Os, where B is the block......-size and M is the size of internal memory. For weighted undirected graphs we present a cache-aware APSP algorithm that performs O(V · ( V E B +E B log E B )) I/Os. We also present efficient cacheaware algorithms that find paths between all pairs of vertices in an unweighted graph with lengths within a small...... additive constant of the shortest path length. All of our results improve earlier results known for these problems. For approximate APSP we provide the first nontrivial results. Our diameter result uses O(V + E) extra space, and all of our other algorithms use O(V 2) space....
Delay Tolerant Network Routing Nature – A Study
Directory of Open Access Journals (Sweden)
V. Prema Tulasi
2014-04-01
Full Text Available Delay-Tolerant network (DTN is a network in which no simultaneous end-to-end path exists. And the messages delivered in the DTN usually have large delivery latency due to network partition. These special characteristics make DTN routing a challenging problem. For this purpose, we updated the shortest path based routing algorithms using conditional intermeeting times and proposed to route the messages over conditional shortest paths. This proposes Conditional Shortest Path Routing (CSPR protocol that route the messages over conditional shortest paths in which the cost of links between nodes is defined by conditional intermeeting times rather than the conventional intermeeting times.
All-pairs Shortest Path Algorithm based on MPI+CUDA Distributed Parallel Programming Model
Directory of Open Access Journals (Sweden)
Qingshuang Wu
2013-12-01
Full Text Available In view of the problem that computing shortest paths in a graph is a complex and time-consuming process, and the traditional algorithm that rely on the CPU as computing unit solely can't meet the demand of real-time processing, in this paper, we present an all-pairs shortest paths algorithm using MPI+CUDA hybrid programming model, which can take use of the overwhelming computing power of the GPU cluster to speed up the processing. This proposed algorithm can combine the advantages of MPI and CUDA programming model, and can realize two-level parallel computing. In the cluster-level, we take use of the MPI programming model to achieve a coarse-grained parallel computing between the computational nodes of the GPU cluster. In the node-level, we take use of the CUDA programming model to achieve a GPU-accelerated fine grit parallel computing in each computational node internal. The experimental results show that the MPI+CUDA-based parallel algorithm can take full advantage of the powerful computing capability of the GPU cluster, and can achieve about hundreds of time speedup; The whole algorithm has good computing performance, reliability and scalability, and it is able to meet the demand of real-time processing of massive spatial shortest path analysis
Energy optimization based path selection algorithm for IEEE 802.11s wireless mesh networks
CSIR Research Space (South Africa)
Mhlanga, MM
2011-09-01
Full Text Available when the network is deployed in rural areas where electricity is a scarce resource. This research therefore presents an energy optimization based path selection algorithm for IEEE 802.11s WMNs which is aimed at addressing the above mentioned constrains...
Research and Implementation of the Shortest Path Algorithm in Road Network Model%最短路径算法在路网模型中的研究与实现
Institute of Scientific and Technical Information of China (English)
董文科; 赵俊三; 杨哲; 陈雷
2016-01-01
传统的基于距离的路网模型以车辆通过的距离为权值计算最短路径，该模型无法满足基于时间的计算。要解决时间路网模型的设计问题，应该在基于距离的最短路径研究中，将动态的阻抗系数在计算机中表示出来，在算法实现过程中，解决如何在不同情况下调用不同的阻抗系数来选择相应情况下最合适的时间最短路径问题。%The traditional network model based on distance calculates the shortest path with the distance that the vehicle travels as the weights, and it can't meet the calculation based on time. In order to solve the design of the time road network model, we need to show the dynamic impedance coefficient in the computer in the shortest path based on distance. In the process of algorithm implementation, the problems of calling different resistance coefficients in different situation to select the most proper time-saving path in the corresponding cases shall be solved.
Distributed multiple path routing in complex networks
Chen, Guang; Wang, San-Xiu; Wu, Ling-Wei; Mei, Pan; Yang, Xu-Hua; Wen, Guang-Hui
2016-12-01
Routing in complex transmission networks is an important problem that has garnered extensive research interest in the recent years. In this paper, we propose a novel routing strategy called the distributed multiple path (DMP) routing strategy. For each of the O-D node pairs in a given network, the DMP routing strategy computes and stores multiple short-length paths that overlap less with each other in advance. And during the transmission stage, it rapidly selects an actual routing path which provides low transmission cost from the pre-computed paths for each transmission task, according to the real-time network transmission status information. Computer simulation results obtained for the lattice, ER random, and scale-free networks indicate that the strategy can significantly improve the anti-congestion ability of transmission networks, as well as provide favorable routing robustness against partial network failures.
Runtime analysis of ant colony optimization on dynamic shortest path problems
DEFF Research Database (Denmark)
Lissovoi, Andrei; Witt, Carsten
2013-01-01
A simple ACO algorithm called λ-MMAS for dynamic variants of the single-destination shortest paths problem is studied by rigorous runtime analyses. Building upon previous results for the special case of 1-MMAS, it is studied to what extent an enlarged colony using $\\lambda$ ants per vertex helps...
ESTIMATION OF OPTIMAL PATH ON URBAN ROAD NETWORKS USING AHP ALGORITHM
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Surendra Kukadapwar
2016-03-01
Full Text Available This paper describes to develop a multi criteria decision based methodology to find optimal path in real urban road network. Over the year several studies were conducted but most of which rely on single variable like travel distance or travel time as cost function. In this study, seven different attributes influencing the traffic network i.e. distance, time, traffic volume, road width, no. of intersection, parking and encroachment on road are used to define cost function using multi criterion decision making approach. These variables are combined using a Multi-Dimensional Cost Model (MDCM using the Analytical Hierarchical Process (AHP. The models developed were implemented and closely evaluated in Nagpur city of India. Model is considered for determining optimal path between various Origins and Destinations in real urban traffic network. Composite weighted AHP scored were used to generate AHP decision surface. Finally, the best decision was proposed by generating the least cost path which is considered as optimal path. The resulting routes showed to be more accurate than those obtained utilizing one-dimensional cost functions and AHP is found to be effective tool to deal with optimal route selection problem.
Randomized shortest-path problems: two related models.
Saerens, Marco; Achbany, Youssef; Fouss, François; Yen, Luh
2009-08-01
This letter addresses the problem of designing the transition probabilities of a finite Markov chain (the policy) in order to minimize the expected cost for reaching a destination node from a source node while maintaining a fixed level of entropy spread throughout the network (the exploration). It is motivated by the following scenario. Suppose you have to route agents through a network in some optimal way, for instance, by minimizing the total travel cost-nothing particular up to now-you could use a standard shortest-path algorithm. Suppose, however, that you want to avoid pure deterministic routing policies in order, for instance, to allow some continual exploration of the network, avoid congestion, or avoid complete predictability of your routing strategy. In other words, you want to introduce some randomness or unpredictability in the routing policy (i.e., the routing policy is randomized). This problem, which will be called the randomized shortest-path problem (RSP), is investigated in this work. The global level of randomness of the routing policy is quantified by the expected Shannon entropy spread throughout the network and is provided a priori by the designer. Then, necessary conditions to compute the optimal randomized policy-minimizing the expected routing cost-are derived. Iterating these necessary conditions, reminiscent of Bellman's value iteration equations, allows computing an optimal policy, that is, a set of transition probabilities in each node. Interestingly and surprisingly enough, this first model, while formulated in a totally different framework, is equivalent to Akamatsu's model ( 1996 ), appearing in transportation science, for a special choice of the entropy constraint. We therefore revisit Akamatsu's model by recasting it into a sum-over-paths statistical physics formalism allowing easy derivation of all the quantities of interest in an elegant, unified way. For instance, it is shown that the unique optimal policy can be obtained by
Directory of Open Access Journals (Sweden)
Bi-Qing Li
2013-01-01
Full Text Available Lung cancer is one of the leading causes of cancer mortality worldwide. The main types of lung cancer are small cell lung cancer (SCLC and nonsmall cell lung cancer (NSCLC. In this work, a computational method was proposed for identifying lung-cancer-related genes with a shortest path approach in a protein-protein interaction (PPI network. Based on the PPI data from STRING, a weighted PPI network was constructed. 54 NSCLC- and 84 SCLC-related genes were retrieved from associated KEGG pathways. Then the shortest paths between each pair of these 54 NSCLC genes and 84 SCLC genes were obtained with Dijkstra’s algorithm. Finally, all the genes on the shortest paths were extracted, and 25 and 38 shortest genes with a permutation P value less than 0.05 for NSCLC and SCLC were selected for further analysis. Some of the shortest path genes have been reported to be related to lung cancer. Intriguingly, the candidate genes we identified from the PPI network contained more cancer genes than those identified from the gene expression profiles. Furthermore, these genes possessed more functional similarity with the known cancer genes than those identified from the gene expression profiles. This study proved the efficiency of the proposed method and showed promising results.
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Mazyar Seraj
2014-10-01
Full Text Available This paper describes an experimental study of learning Dijkstra’s shortest path algorithm on mobile devices. The aim of the study is to investigate and compare the impacts of two different mobile screen user interfaces on students’ satisfaction for learning the technical subject. A mobile learning prototype was developed for learning Dijkstra’s shortest path algorithm on Apple iPhone 4 operated on iPhone operating system (iOS, and Acer Inconia Tab operated on an Android operating system. Thirty students, who are either currently studying or had previously studied Computer Networks, were recruited for the usability trial. At the end of each single session, students’ satisfaction interacting with the two mobile devices was measured using QUIS questionnaire. Although there is no significant difference in students’ satisfaction between the two different mobile screen interfaces, the subjective findings indicate that Acer Inconia Tab gained higher scores as compared to Apple iPhone 4.
An optimal routing strategy on scale-free networks
Yang, Yibo; Zhao, Honglin; Ma, Jinlong; Qi, Zhaohui; Zhao, Yongbin
Traffic is one of the most fundamental dynamical processes in networked systems. With the traditional shortest path routing (SPR) protocol, traffic congestion is likely to occur on the hub nodes on scale-free networks. In this paper, we propose an improved optimal routing (IOR) strategy which is based on the betweenness centrality and the degree centrality of nodes in the scale-free networks. With the proposed strategy, the routing paths can accurately bypass hub nodes in the network to enhance the transport efficiency. Simulation results show that the traffic capacity as well as some other indexes reflecting transportation efficiency are further improved with the IOR strategy. Owing to the significantly improved traffic performance, this study is helpful to design more efficient routing strategies in communication or transportation systems.
Tabu Search Technique for Solving the Routing Problem%禁忌搜索算法用于解决网络路由问题
Institute of Scientific and Technical Information of China (English)
王东平; 李绍荣
2003-01-01
Routing problem is a very import problem in the network design. However, with the increasing of the number of vertices, the convergence speed of the conventional method (such as the Dijkstra algorithm) becomes slow. In some services, the accurate shortest path isn't requested. This paper presents a new algorithm for solving this problem based on the tabu search technique. The tabu search algorithm can get the satisfied path with the changing of the iteration times, the tabu period and neighborhood size. Simulation results demonstrate that the proposed method is very efficient for computing the shorted path, especially when the scale of the network is large.
Finding of Shortest Path from Source to Destination by Traversing every Node in wired Network.
Avdhesh kumar sharma; Sourabh kumar
2013-01-01
At present communication and transportation has an important place in every person life in their all business and non-business task. In daily life everybody is facing a problem of choosing a shortest pathfrom one location to another location. Shortest path means the path which has minimum mileage or distance covered. It saves time and money both which are essential parts of our life. In this paper, wewant to propose a technique to resolving this problem by traversing the whole network and fin...
DEFF Research Database (Denmark)
Vacca, Alessandro; Prato, Carlo Giacomo; Meloni, Italo
2015-01-01
is the dependency of the parameter estimates from the choice set generation technique. Bias introduced in model estimation has been corrected only for the random walk algorithm, which has problematic applicability to large-scale networks. This study proposes a correction term for the sampling probability of routes...... extracted with stochastic route generation. The term is easily applicable to large-scale networks and various environments, given its dependence only on a random number generator and the Dijkstra shortest path algorithm. The implementation for revealed preferences data, which consist of actual route choices...... collected in Cagliari, Italy, shows the feasibility of generating routes stochastically in a high-resolution network and calculating the correction factor. The model estimation with and without correction illustrates how the correction not only improves the goodness of fit but also turns illogical signs...
Efficient evaluation of shortest travel-time path queries through spatial mashups
Zhang, Detian
2017-01-07
In the real world, the route/path with the shortest travel time in a road network is more meaningful than that with the shortest network distance for location-based services (LBS). However, not every LBS provider has adequate resources to compute/estimate travel time for routes by themselves. A cost-effective way for LBS providers to estimate travel time for routes is to issue external route requests to Web mapping services (e.g., Google Maps, Bing Maps, and MapQuest Maps). Due to the high cost of processing such external route requests and the usage limits of Web mapping services, we take the advantage of direction sharing, parallel requesting and waypoints supported by Web mapping services to reduce the number of external route requests and the query response time for shortest travel-time route queries in this paper. We first give the definition of sharing ability to reflect the possibility of sharing the direction information of a route with others, and find out the queries that their query routes are independent with each other for parallel processing. Then, we model the problem of selecting the optimal waypoints for an external route request as finding the longest simple path in a weighted complete digraph. As it is a MAX SNP-hard problem, we propose a greedy algorithm with performance guarantee to find the best set of waypoints in an external route request. We evaluate the performance of our approach using a real Web mapping service, a real road network, real and synthetic data sets. Experimental results show the efficiency, scalability, and applicability of our approach.
Modeling the average shortest-path length in growth of word-adjacency networks
Kulig, Andrzej; DroŻdŻ, Stanisław; Kwapień, Jarosław; OświÈ©cimka, Paweł
2015-03-01
We investigate properties of evolving linguistic networks defined by the word-adjacency relation. Such networks belong to the category of networks with accelerated growth but their shortest-path length appears to reveal the network size dependence of different functional form than the ones known so far. We thus compare the networks created from literary texts with their artificial substitutes based on different variants of the Dorogovtsev-Mendes model and observe that none of them is able to properly simulate the novel asymptotics of the shortest-path length. Then, we identify the local chainlike linear growth induced by grammar and style as a missing element in this model and extend it by incorporating such effects. It is in this way that a satisfactory agreement with the empirical result is obtained.
COAR: Combining Arc flag with Reach based method for shortest path computation
Thangalatha legaz.C
2012-01-01
In general shortest path computation from onenode to another in a directed graph is a verycommon task. This problem is fundamentally solvedby the Dijkstra algorithm. There are manytechniques available to speed up the originalDijkstra’s algorithm heuristically. Even then theoptimality of the solution can still be guaranteed.In this project, the various combinations of speeduptechniques are studied and analyzed. By analyzingthe advantages of the arc flag method and reachbased method, the combin...
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Syed Bilal Hussain Shah
2017-01-01
Full Text Available In Wireless Sensors Networks (WSNs, researcher’s main focus is on energy preservation and prolonging network lifetime. More energy resources are required in case of remote applications of WSNs, where some of the nodes die early that shorten the lifetime and decrease the stability of the network. It is mainly caused due to the non-optimal Cluster Heads (CHs selection based on single criterion and uneven distribution of energy. We propose a new clustering protocol for both homogeneous and heterogeneous environments, named as Optimized Path planning algorithm with Energy efficiency and Extending Network lifetime in WSN (OPEN. In the proposed protocol, timer value concept is used for CH selection based on multiple criteria. Simulation results prove that OPEN performs better than the existing protocols in terms of the network lifetime, throughput and stability. The results explicitly explain the cluster head selection of OPEN protocol and efficient solution of uneven energy distribution problem.
Calibration of neural networks using genetic algorithms, with application to optimal path planning
Smith, Terence R.; Pitney, Gilbert A.; Greenwood, Daniel
1987-01-01
Genetic algorithms (GA) are used to search the synaptic weight space of artificial neural systems (ANS) for weight vectors that optimize some network performance function. GAs do not suffer from some of the architectural constraints involved with other techniques and it is straightforward to incorporate terms into the performance function concerning the metastructure of the ANS. Hence GAs offer a remarkably general approach to calibrating ANS. GAs are applied to the problem of calibrating an ANS that finds optimal paths over a given surface. This problem involves training an ANS on a relatively small set of paths and then examining whether the calibrated ANS is able to find good paths between arbitrary start and end points on the surface.
An Energy-Efficient Routing and Self-Organization Algorithm in Wireless Sensor Networks
Institute of Scientific and Technical Information of China (English)
LIU Li-feng; ZOU Shi-hong; ZHANG Lei; CHENG Shi-duan
2005-01-01
Energy efficiency is the most important goal in wireless sensor network routing and self-organization algorithms. To achieve this goal, our paper first presents a distributed energy-aware routing algorithm Nearest to Theoretical Point(NTP). Then it applies NTP to self-organization of sensor networks to form an energy-efficient self-organization algorithm Shortest Path Tree-NTP(SPT-NTP). Theoretic analysis and simulation show that NTP and SPT-NTP can ensure less network energy consumption than other related algorithms.
Jafarizadeh, Saber
2010-01-01
Providing an analytical solution for the problem of finding Fastest Distributed Consensus (FDC) is one of the challenging problems in the field of sensor networks. Most of the methods proposed so far deal with the FDC averaging algorithm problem by numerical convex optimization methods and in general no closed-form solution for finding FDC has been offered up to now except in [3] where the conjectured answer for path has been proved. Here in this work we present an analytical solution for the problem of Fastest Distributed Consensus for the Path network using semidefinite programming particularly solving the slackness conditions, where the optimal weights are obtained by inductive comparing of the characteristic polynomials initiated by slackness conditions.
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
Dijkstra algorithm is a basic algorithm to analyze the vehicle routing problem (VRP) in the terminal distribution of logistics center. According to the actual client demands of service speed and quality, the conceptions of economical distance of delivery and the best routing algorithm were given on the base of the Dijkstra algorithm with consideration of a coefficient of the road hustle degree. Economical distance of delivery is the shortest physical distance between two customers. It is the value of goods delivery in shortest distance when concerning factors such as the road length, the hustle degree, the driveway quantity, and the type of the road. The improved algorithm is being used in the development and application of a distribution path information system in the terminal distribution of logistics center. The simulation and practical case prove that the algorithm is effective and reasonable.
The Study of Evacuation Route Algorithm in Flooding by Localized Heavy Rain
Institute of Scientific and Technical Information of China (English)
Ming Zhang; Eunmi Kim; Yun Sung Go; Chang Soo Kim
2014-01-01
Flooding is one of the worst hazards of natural disaster. One of the adverse effect of flooding is that it disrupts the traffic system of a city or nation. Therefore, finding the safe path to the destination to drivers is required to implement an efficient evacuation system during a heavy rain. How to efficiently evacuate people in a road is required as well. In this study, we compared the A* algorithm and Dijkstra algorithm to find an optimal and efficient path between departure point to destination point if there is a hazard area. The result indicates A* algorithm can find the shorter optimal path better Dijkstra algorithm. We develop the evacuation route algorithm using A* algorithm when this algorithm was used in evacuation route, the road network was graded according to the flooding history and flooding danger area which is defined by lowland area information. We simulate the suggested algorithm for the test experiments demonstrate that this algorithm can enhance the efficiency of evacuation route in Busan.
An Approach In Optimization Of Ad-Hoc Routing Algorithms
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Sarvesh Kumar Sharma
2012-06-01
Full Text Available In this paper different optimization of Ad-hoc routing algorithm is surveyed and a new method using training based optimization algorithm for reducing the complexity of routing algorithms is suggested. A binary matrix is assigned to each node in the network and gets updated after each data transfer using the protocols. The use of optimization algorithm in routing algorithm can reduce the complexity of routing to the least amount possible.
2016-01-01
The state-of-the-art methods for protein-protein interaction (PPI) extraction are primarily based on kernel methods, and their performances strongly depend on the handcraft features. In this paper, we tackle PPI extraction by using convolutional neural networks (CNN) and propose a shortest dependency path based CNN (sdpCNN) model. The proposed method (1) only takes the sdp and word embedding as input and (2) could avoid bias from feature selection by using CNN. We performed experiments on sta...
A new efficient optimal path planner for mobile robot based on Invasive Weed Optimization algorithm
Mohanty, Prases K.; Parhi, Dayal R.
2014-12-01
Planning of the shortest/optimal route is essential for efficient operation of autonomous mobile robot or vehicle. In this paper Invasive Weed Optimization (IWO), a new meta-heuristic algorithm, has been implemented for solving the path planning problem of mobile robot in partially or totally unknown environments. This meta-heuristic optimization is based on the colonizing property of weeds. First we have framed an objective function that satisfied the conditions of obstacle avoidance and target seeking behavior of robot in partially or completely unknown environments. Depending upon the value of objective function of each weed in colony, the robot avoids obstacles and proceeds towards destination. The optimal trajectory is generated with this navigational algorithm when robot reaches its destination. The effectiveness, feasibility, and robustness of the proposed algorithm has been demonstrated through series of simulation and experimental results. Finally, it has been found that the developed path planning algorithm can be effectively applied to any kinds of complex situation.
A New Approach to VC Routing in ATM Networks
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
A new ant-algorithm-based routing approach is proposed for the VC routing problem with considering the comprehensive effect between the resource utilization and the load balance in ATM networks. In the approach, the backup paths are calculated first, and then an ant algorithm based on the ability of ants to find the shortest path between their nest and the food source during their searching food, is constructed to optimize the VC global route.Simulation results show that the proposed approach can realize VC routing effectively according to the current traffic states in the networks and the user-specified delay requirements.
Runtime analysis of ant colony optimization on dynamic shortest path problems
DEFF Research Database (Denmark)
Lissovoi, Andrei; Witt, Carsten
2015-01-01
A simple ACO algorithm called lambda-MMAS for dynamic variants of the single-destination shortest paths problem is studied by rigorous runtime analyses. Building upon previous results for the special case of 1-MMAS, it is studied to what extent an enlarged colony using lambda ants per vertex helps...... in tracking an oscillating optimum. It is shown that easy cases of oscillations can be tracked by a constant number of ants. However, the paper also identifies more involved oscillations that with overwhelming probability cannot be tracked with any polynomial-size colony. Finally, parameters of dynamic...
A DISTRIBUTED QOS ROUTING BASED ON ANT ALGORITHM FOR LEO SATELLITE NETWORK
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
Low Earth Orbit (LEO) satellites provide short round-trip delays and are becoming increasingly important. One of the challenges in LEO satellite networks is the development of specialized and efficient routing algorithms. To satisfy the QoS requirements of multimedia applications, satellite routing protocols should consider handovers and minimize their effect on the active connections. A distributed QoS routing scheme based on heuristic ant algorithm is proposed for satisfying delay bound and avoiding link congestion. Simulation results show that the call blocking probabilities of this algorithm are less than that of Shortest Path First (SPF) with different delay bound.
Analysis of Average Shortest-Path Length of Scale-Free Network
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Guoyong Mao
2013-01-01
Full Text Available Computing the average shortest-path length of a large scale-free network needs much memory space and computation time. Hence, parallel computing must be applied. In order to solve the load-balancing problem for coarse-grained parallelization, the relationship between the computing time of a single-source shortest-path length of node and the features of node is studied. We present a dynamic programming model using the average outdegree of neighboring nodes of different levels as the variable and the minimum time difference as the target. The coefficients are determined on time measurable networks. A native array and multimap representation of network are presented to reduce the memory consumption of the network such that large networks can still be loaded into the memory of each computing core. The simplified load-balancing model is applied on a network of tens of millions of nodes. Our experiment shows that this model can solve the load-imbalance problem of large scale-free network very well. Also, the characteristic of this model can meet the requirements of networks with ever-increasing complexity and scale.
An energy efficient multipath routing algorithm for wireless sensor networks
Dulman, Stefan; Wu, Jian; Havinga, Paul
2003-01-01
In this paper we introduce a new routing algorithm for wireless sensor networks. The aim of this algorithm is to provide on-demand multiple disjoint paths between a data source and a destination. Our Multipath On-Demand Routing Algorithm (MDR) improves the reliability of data routing in a wireless m
Institute of Scientific and Technical Information of China (English)
王建新; 王新辉; 彭革刚
2002-01-01
An important issue for providing better guarantees of Quality of Service (QoS) to applications is QoS rout-ing. The task of QoS routing is to determine a feasible path that satisfies a set of constraints while maintaining high u-tilization of network resources. For the purpose of achieving the latter objective additional optimality requirementsneed to be imposed. In general, multi-constrained path selection problem is NP-hard so it cannot be exactly solved inpolynomial time. Accordingly heuristics and approximation algorithms with polynomial or pseudo-polynomial timecomplexity are often used to deal with this problem. However, many of these algorithms suffer from either excessivecomputational complexity that cannot be used for online network operation or low performance. Moreover, they gen-erally deal with special cases of the problem (e. g. , two constraints without optimization, one constraint with opti-mization, etc. ). In this paper, the authors propose a new efficient algorithm (EAMCOP) for the problem. Makinguse of efficient pruning policy, the algorithm reduces greatly the size of search space and improves the computationalperformance. Although the proposed algorithm has exponential time complexity in the worst case, it can get verygood performance in real networks. The reason is that when the scale of network increases, EAMCOP controls effi-ciently the size of search space by constraint conditions and prior queue that improves computational efficiency. Theresults of simulation show that the algorithm has good performance and can solve effectively multi-constrained opti-mal path (MCOP) problem.
Modelling of the optimal vehicle route in terrain in emergency situations using GIS data
Rybansky, M.
2014-02-01
Most navigation systems in transport are oriented towards the search for optimal paths (shortest or fastest), using vector GIS data. At the time of natural disasters and emergency situations is necessary to consider roads and terrain for transport. This article is focused on finding optimal routes in terrain, which contains a number of point, line and area obstacles. The most frequent point obstacles are trees in the forest. The paper analyzes the typical structure of tree stands in the forest, their characteristics in GIS databases, as well as dimensional parameters of vehicles moving in the forest. The quality of these data is a prerequisite for finding routes between point obstacles. Searching for the fastest or shortest route of the vehicle described in this article is based on the use of the relationship between the Delaunay triangulation and Voronoi graph, the application of Dijkstra's algorithm and the optimization of fractional line. The above-mentioned methods are also exploitable for searching for the shortest route of movement among line obstructions and area obstructions, such route can be apprehended as the joining of points defining impassable terrain. In such a case, the condition must be met that the distance of terminal points of joins has to be adjusted to the extent that it will be shorter than a vehicle width increased by safe margin.
A Relatively Optimal Cross-layer Routing Algorithm in Wireless Mesh Network
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Yue Lu
2011-10-01
Full Text Available Routing in Wireless Network is challenging because of the unpredictable behavior of the medium and the proactive effect of interference. All of these factors lead to poor performance in multi-hop wireless mesh networks specially with the conventional routing. In order to exploit all the advantages that the wireless medium offers, new routing metrics must be explored. These metrics should come from across-layer approach in order to make the routing layer aware of the local issues of the underling layers and even change some parameters of the PHY layer. In the paper, we explore three primitive physical layer parameters: bite error rate(BER, interference, and transmission power. We define the metric so that the network layer can correctly find paths that offer: low levels of bite error rate ,reliability in terms of packet success rate, and relatively low power.
Energy Aware Simple Ant Routing Algorithm for Wireless Sensor Networks
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Sohail Jabbar
2015-01-01
Full Text Available Network lifetime is one of the most prominent barriers in deploying wireless sensor networks for large-scale applications because these networks employ sensors with nonrenewable scarce energy resources. Sensor nodes dissipate most of their energy in complex routing mechanisms. To cope with limited energy problem, we present EASARA, an energy aware simple ant routing algorithm based on ant colony optimization. Unlike most algorithms, EASARA strives to avoid low energy routes and optimizes the routing process through selection of least hop count path with more energy. It consists of three phases, that is, route discovery, forwarding node, and route selection. We have improved the route discovery procedure and mainly concentrate on energy efficient forwarding node and route selection, so that the network lifetime can be prolonged. The four possible cases of forwarding node and route selection are presented. The performance of EASARA is validated through simulation. Simulation results demonstrate the performance supremacy of EASARA over contemporary scheme in terms of various metrics.
Directory of Open Access Journals (Sweden)
Praveen Kumar
2014-10-01
Full Text Available This paper discusses the methodology used in the development of advanced traveller information system (ATIS. This system is designed as a part of web geographical information system (GIS based advanced public transport systems. Web GIS-based ATIS system includes spatial data for the designed functionalities and provides GIS capabilities to the users through the internet. In addition to these functionalities, a route planning algorithm to plan the shortest route between the selected bus transit points is also designed using ant system algorithm and is integrated with web GIS. This study presents the ant system algorithm adopted for the shortest route finding with the methodology developed for the web GIS-based ATIS system for the study area of the city Chandigarh in India using open source software MapServer as web map server. This study also discusses the three-tier logical architecture used in the methodology for providing GIS capabilities to the user over the internet.
An efficient QoS-aware routing algorithm for LEO polar constellations
Tian, Xin; Pham, Khanh; Blasch, Erik; Tian, Zhi; Shen, Dan; Chen, Genshe
2013-05-01
In this work, a Quality of Service (QoS)-aware routing (QAR) algorithm is developed for Low-Earth Orbit (LEO) polar constellations. LEO polar orbits are the only type of satellite constellations where inter-plane inter-satellite links (ISLs) are implemented in real world. The QAR algorithm exploits features of the topology of the LEO satellite constellation, which makes it more efficient than general shortest path routing algorithms such as Dijkstra's or extended Bellman-Ford algorithms. Traffic density, priority, and error QoS requirements on communication delays can be easily incorporated into the QAR algorithm through satellite distances. The QAR algorithm also supports efficient load balancing in the satellite network by utilizing the multiple paths from the source satellite to the destination satellite, and effectively lowers the rate of network congestion. The QAR algorithm supports a novel robust routing scheme in LEO polar constellation, which is able to significantly reduce the impact of inter-satellite link (ISL) congestions on QoS in terms of communication delay and jitter.
Route Optimization in Network Mobility
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Md. Hasan Tareque
2013-01-01
Full Text Available NEtwork MObility (NEMO controls mobility of a number of mobile nodes in a comprehensive way using one or more mobile routers. To choose a route optimization scheme, it is very important to have a quantitative comparison of the available route optimization schemes. The focus of this paper is to analyze the degree of Route Optimization (RO, deploy-ability and type of RO supported by each class in general. The comparison shows the differences among the schemes in terms of issues, such as additional header, signaling and memory requirement. We classify the schemes established on the basic method for route optimization, and equal the schemes based on protocol overhead, such as header overhead, amount of signaling, and memory requirements. Lastly the performance of the classes of different schemes has to be estimated under norms such as available bandwidth, topology of the mobile network and mobility type.
Shortest Paths With Side Sensors
Salaris, Paolo; Bicchi, Antonio
2011-01-01
We present a complete characterization of shortest paths to a goal position for a vehicle with unicycle kinematics and a limited range sensor, constantly keeping a given landmark in sight. Previous work on this subject studied the optimal paths in case of a frontal, symmetrically limited Field--Of--View (FOV). In this paper we provide a generalization to the case of arbitrary FOVs, including the case that the direction of motion is not an axis of symmetry for the FOV, and even that it is not contained in the FOV. The provided solution is of particular relevance to applications using side-scanning, such as e.g. in underwater sonar-based surveying and navigation.
Mathematical Aspects of Network Routing Optimization
Oliveira, Carlos AS
2011-01-01
Before the appearance of broadband links and wireless systems, networks have been used to connect people in new ways. Now, the modern world is connected through large-scale, computational networked systems such as the Internet. Because of the ever-advancing technology of networking, efficient algorithms have become increasingly necessary to solve some of the problems developing in this area. "Mathematical Aspects of Network Routing Optimization" focuses on computational issues arising from the process of optimizing network routes, such as quality of the resulting links and their reli
物流配送路径延伸问题两阶段寻优策略算法%A Two-stage Optimization Algorithm for the Distribution Route Extension Problem
Institute of Scientific and Technical Information of China (English)
何方
2012-01-01
首先根据实际路径资料构建非完全有向图,利用Dijkstra算法得到任意两点之间的最优路径,根据要求虚拟合并或删除非目的地节点,对图形进行简化,重新构造出包含所有有效路径信息和有效节点的非完全有向图,在此基础上运用非完全有向图TSP问题的求解方法进行路径优化.通过示例验证了该算法对于解决物流配送中的此类特定问题是有效的.%In this paper,a non-complete directed graph is drawn according to practical route information and materials and the Dijkstra algorithm is used to calculate the shortest path between any given two points. Then the graph is simplified through virtual combining or deleting the non-destination points as is required and restructured into a non-complete directed graph containing information concerning all feasible routes and points, on the basis of which a solution to the Traveling Salesman Problem of the graph is developed to optimize the distribution routing. Finally a numerical example is used to illustrate the validity of this algorithm in distribution routing problems.
AN OPTIMUM VEHICULAR PATH ALGORITHM FOR TRAFFIC NETWORK BASED ON HIERARCHICAL SPATIAL REASONING
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
Human beings' intellection is the characteristic of a distinct hierarchy and can be taken to construct a heuristic in the shortest path algorithms.It is detailed in this paper how to utilize the hierarchical reasoning on the basis of greedy and directional strategy to establish a spatial heuristic,so as to improve running efficiency and suitability of shortest path algorithm for traffic network.The authors divide urban traffic network into three hierarchies and set forward a new node hierarchy division rule to avoid the unreliable solution of shortest path.It is argued that the shortest path,no matter distance shortest or time shortest,is usually not the favorite of drivers in practice.Some factors difficult to expect or quantify influence the drivers' choice greatly.It makes the drivers prefer choosing a less shortest,but more reliable or flexible path to travel on.The presented optimum path algorithm,in addition to the improvement of the running efficiency of shortest path algorithms up to several times,reduces the emergence of those factors,conforms to the intellection characteristic of human beings,and is more easily accepted by drivers.Moreover,it does not require the completeness of networks in the lowest hierarchy and the applicability and fault tolerance of the algorithm have improved.The experiment result shows the advantages of the presented algorithm.The authors argued that the algorithm has great potential application for navigation systems of large-scale traffic networks.
Directory of Open Access Journals (Sweden)
Lei Hua
2016-01-01
Full Text Available The state-of-the-art methods for protein-protein interaction (PPI extraction are primarily based on kernel methods, and their performances strongly depend on the handcraft features. In this paper, we tackle PPI extraction by using convolutional neural networks (CNN and propose a shortest dependency path based CNN (sdpCNN model. The proposed method (1 only takes the sdp and word embedding as input and (2 could avoid bias from feature selection by using CNN. We performed experiments on standard Aimed and BioInfer datasets, and the experimental results demonstrated that our approach outperformed state-of-the-art kernel based methods. In particular, by tracking the sdpCNN model, we find that sdpCNN could extract key features automatically and it is verified that pretrained word embedding is crucial in PPI task.
Hua, Lei; Quan, Chanqin
2016-01-01
The state-of-the-art methods for protein-protein interaction (PPI) extraction are primarily based on kernel methods, and their performances strongly depend on the handcraft features. In this paper, we tackle PPI extraction by using convolutional neural networks (CNN) and propose a shortest dependency path based CNN (sdpCNN) model. The proposed method (1) only takes the sdp and word embedding as input and (2) could avoid bias from feature selection by using CNN. We performed experiments on standard Aimed and BioInfer datasets, and the experimental results demonstrated that our approach outperformed state-of-the-art kernel based methods. In particular, by tracking the sdpCNN model, we find that sdpCNN could extract key features automatically and it is verified that pretrained word embedding is crucial in PPI task.
An algorithm for link restoration of wavelength routing optical networks
DEFF Research Database (Denmark)
Limal, Emmanuel; Stubkjær, Kristian
1999-01-01
We present an algorithm for restoration of single link failure in wavelength routing multihop optical networks. The algorithm is based on an innovative study of networks using graph theory. It has the following original features: it (i) assigns working and spare channels simultaneously, (ii...... low complexity is studied in detail and compared to the complexity of a classical path assignment algorithm. Finally, we explain how to use the algorithm to control the restoration path lengths....
Threshold-Based Shortest Path Query over Large Correlated Uncertain Graphs
Institute of Scientific and Technical Information of China (English)
成雨蓉; 袁野; 陈雷; 王国仁
2015-01-01
With the popularity of uncertain data, queries over uncertain graphs have become a hot topic in the database community. As one of the important queries, the shortest path query over an uncertain graph has attracted much attention of researchers due to its wide applications. Although there are some eﬃcient solutions addressing this problem, all existing models ignore an important property existing in uncertain graphs: the correlation among the edges sharing the same vertex. In this paper, we apply Markov network to model the hidden correlation in uncertain graphs and compute the shortest path. Unfortunately, calculating the shortest path and corresponding probability over uncertain graphs modeled by Markov networks is a #P-hard problem. Thus, we propose a filtering-and-verification framework to accelerate the queries. In the filtering phase, we design a probabilistic shortest path index based on vertex cuts and blocks of a graph. We find a series of upper bounds and prune the vertices and edges whose upper bounds of the shortest path probability are lower than the threshold. By carefully picking up the blocks and vertex cuts, the index is optimized to have the maximum pruning capability, so that we can filter a large number of vertices which make no contribution to the final shortest path query results. In the verification phase, we develop an eﬃcient sampling algorithm to determine the final query answers. Finally, we verify the eﬃciency and effectiveness of our solutions with extensive experiments.
Wavelength Routing Algorithm of All Optical Network Based on Traffic Engineering
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
General multi-protocol label switching(GMPLS) based on traffic engineering is one of the possible methods to implement all-optical network. This method implements the network with IP technique and guarantees the quality of service with traffic engineering. Based on the establishment of selecting schemes of optical path and methods of traffic calculation, the wavelength routing algorithm of all-optical network based on traffic engineering is presented by combining with prior route of shortest path and traffic engineering, the algorithm procedures are given, and the actual examples are introduced as well as the analysis on simulation calculation. This research results have certain significance for the achievement of optical switching technique of all-optical network.
Service Priority based Reliable Routing Path Select Method in Smart Grid Communication Network
Directory of Open Access Journals (Sweden)
Kaixuan Wang
2012-11-01
Full Text Available The new challenges and schemes for the Smart Grid require high reliable transmission technologiesto support various types of electrical services and applications. This paper concentrates the degree of importance of services and tries to allocate more important service to more reliable network routing path to deliver the key instructions in the Smart Grid communication networks. Pareto probability distribution is used to weight the reliability of IP-based router path. In order to definition the relationship of service and reliability of router path, we devise a mapping and optimal function is presented to access. An optimal method is used for adapting to find the appropriate value to match the objective function. Finally, we validate the proposed algorithms by experiments. The simulation results show that the proposed algorithm outperforms the random routing algorithms.
Institute of Scientific and Technical Information of China (English)
罗义学
2011-01-01
基于智能Petri网构建了物流配送路径的优化模型.通过定义智能Petri网的运行规则,得到了基于智能Petri网的物流配送路径优化算法与计算流程,分析了车辆在交叉口的实际延误阻抗时配送分析的影响.该算法具有求解不需要对物流网络图作任何修改和容易实现配送过程的动态模拟的特点,利用该算法可以获取配送车辆从出发点到城市中任何一个节点的最优路径.将算例与改进的Dijkstra算法进行了对比分析,结果表明了该算法的可行性和有效性.%Based on the intelligent Petri net, a logistic delivery path optimization model is constructed. Through defining specific running rules for the intelligent Petri net, an optimization algorithm of logistic delivery path is put forward and calculation process is presented. The actual delay experienced by delivery vehicles at intersections is taken into account for analysis. The algorithm needn' t modify the logistic network and the dynamic version of the delivery process is simulated easily. The shortest path for a delivery vehicle travelling from the starting point to any point in the city is founded. By comparing with the Dijkstra algorithm in a case study, it is proven that our algorithm is both applicable and efficient.
Directory of Open Access Journals (Sweden)
Sohel Rana
2015-03-01
Full Text Available The Wireless Sensor Network (WSN is made up with small batteries powered sensor devices with lim-ited energy resources within it. These sensor nodes are used to monitor physical or environmental conditions and to pass their data through the wireless network to the main location. One of the crucial issues in wireless sensor network is to create a more energy efficient system. Clustering is one kind of mechanism in Wireless Sensor Networks to prolong the network lifetime and to reduce network energy consumption. In this paper, we propose a new routing protocol called Fuzzy Based Energy Effi-cient Multiple Cluster Head Selection Routing Protocol (FEMCHRP for Wireless Sensor Network. The routing process involves the Clustering of nodes and the selection of Cluster Head (CH nodes of these clusters which sends all the information to the Cluster Head Leader (CHL. After that, the cluster head leaders send aggregated data to the Base Station (BS. The selection of cluster heads and cluster head leaders is performed by using fuzzy logic and the data transmission process is performed by shortest energy path which is selected applying Dijkstra Algorithm. The simulation results of this research are compared with other protocols BCDCP, CELRP and ECHERP to evaluate the performance of the proposed routing protocol. The evaluation concludes that the proposed routing protocol is better in prolonging network lifetime and balancing energy consumption.
Global path planning approach based on ant colony optimization algorithm
Institute of Scientific and Technical Information of China (English)
WEN Zhi-qiang; CAI Zi-xing
2006-01-01
Ant colony optimization (ACO) algorithm was modified to optimize the global path. In order to simulate the real ant colonies, according to the foraging behavior of ant colonies and the characteristic of food, conceptions of neighboring area and smell area were presented. The former can ensure the diversity of paths and the latter ensures that each ant can reach the goal. Then the whole path was divided into three parts and ACO was used to search the second part path. When the three parts pathes were adjusted,the final path was found. The valid path and invalid path were defined to ensure the path valid. Finally, the strategies of the pheromone search were applied to search the optimum path. However, when only the pheromone was used to search the optimum path, ACO converges easily. In order to avoid this premature convergence, combining pheromone search and random search, a hybrid ant colony algorithm(HACO) was used to find the optimum path. The comparison between ACO and HACO shows that HACO can be used to find the shortest path.
Optimization for Service Routes of Pallet Service Center Based on the Pallet Pool Mode
He, Shiwei; Song, Rui
2016-01-01
Service routes optimization (SRO) of pallet service center should meet customers' demand firstly and then, through the reasonable method of lines organization, realize the shortest path of vehicle driving. The routes optimization of pallet service center is similar to the distribution problems of vehicle routing problem (VRP) and Chinese postman problem (CPP), but it has its own characteristics. Based on the relevant research results, the conditions of determining the number of vehicles, the one way of the route, the constraints of loading, and time windows are fully considered, and a chance constrained programming model with stochastic constraints is constructed taking the shortest path of all vehicles for a delivering (recycling) operation as an objective. For the characteristics of the model, a hybrid intelligent algorithm including stochastic simulation, neural network, and immune clonal algorithm is designed to solve the model. Finally, the validity and rationality of the optimization model and algorithm are verified by the case. PMID:27528865
Optimization for Service Routes of Pallet Service Center Based on the Pallet Pool Mode
Directory of Open Access Journals (Sweden)
Kang Zhou
2016-01-01
Full Text Available Service routes optimization (SRO of pallet service center should meet customers’ demand firstly and then, through the reasonable method of lines organization, realize the shortest path of vehicle driving. The routes optimization of pallet service center is similar to the distribution problems of vehicle routing problem (VRP and Chinese postman problem (CPP, but it has its own characteristics. Based on the relevant research results, the conditions of determining the number of vehicles, the one way of the route, the constraints of loading, and time windows are fully considered, and a chance constrained programming model with stochastic constraints is constructed taking the shortest path of all vehicles for a delivering (recycling operation as an objective. For the characteristics of the model, a hybrid intelligent algorithm including stochastic simulation, neural network, and immune clonal algorithm is designed to solve the model. Finally, the validity and rationality of the optimization model and algorithm are verified by the case.
Optimization for Service Routes of Pallet Service Center Based on the Pallet Pool Mode.
Zhou, Kang; He, Shiwei; Song, Rui
2016-01-01
Service routes optimization (SRO) of pallet service center should meet customers' demand firstly and then, through the reasonable method of lines organization, realize the shortest path of vehicle driving. The routes optimization of pallet service center is similar to the distribution problems of vehicle routing problem (VRP) and Chinese postman problem (CPP), but it has its own characteristics. Based on the relevant research results, the conditions of determining the number of vehicles, the one way of the route, the constraints of loading, and time windows are fully considered, and a chance constrained programming model with stochastic constraints is constructed taking the shortest path of all vehicles for a delivering (recycling) operation as an objective. For the characteristics of the model, a hybrid intelligent algorithm including stochastic simulation, neural network, and immune clonal algorithm is designed to solve the model. Finally, the validity and rationality of the optimization model and algorithm are verified by the case.
AN AUTOMATED REFERENCE POINT-LIKE APPROACH FOR MULTICRITERIA SHORTEST PATH PROBLEMS
Institute of Scientific and Technical Information of China (English)
Jo(a)o C. N. CL(I)ACO; José M. F. CRAVEIRINHA; Marta M. B. PASCOAL
2006-01-01
In this paper we introduce a method of analysis for the automated ordering and selection of solutions of a multicriteria shortest path model. The method is based on a reference point approach, where the paths in a specific priority region are ranked by non-decreasing order of a Chebyshev metric.In order to list paths according with this objective function a labelling algorithm is proposed. The developed method is applied in a video-traffic routing context. Computational results are presented and analysed, for randomly generated networks of significant dimension.
Directory of Open Access Journals (Sweden)
Anibrika Bright Selorm Kodzo
2016-05-01
Full Text Available Due to the increase in the easy accessibility of computers and mobile phones alike, routing has become indispensable in deciding how computes communicate especially modern computer communication networks. This paper presents performance analysis between EIGRP and OSPFP for real time applications using Optimized Network Engineering Tool (OPNET. In order to evaluate OSPF and EIGRP’s performance, three network models were designed where 1st, 2nd and 3rd network models are configured respectively with OSPF, EIGRP and a combination of EIGRP and OSPF. Evaluation of the proposed routing protocols was performed based on quantitative metrics such as Convergence Time, Jitter, End-to-End delay, Throughput and Packet Loss through the simulated network models. The evaluation results showed that EIGRP protocol provides a better performance than OSPF routing protocol for real time applications. By examining the results (convergence times in particular, the results of simulating the various scenarios identified the routing protocol with the best performance for a large, realistic and scalable network.
Generalized minimum information path routing strategy on scale-free networks
Institute of Scientific and Technical Information of China (English)
Zhou Si-Yuan; Wang Kai; Zhang Yi-Feng; Pei Wen-Jiang; Pu Cun-Lai; Li Wei
2011-01-01
This paper presents a new routing strategy by introducing a tunable parameter into the minimum information path routing strategy we proposed previously.It is found that network transmission capacity can be considerably enhanced by adjusting the parameter with various allocations of node capability for packet delivery.Moreover,the proposed routing strategy provides a traffic load distribution which can better match the allocation of node capability than that of traditional efficient routing strategies,leading to a network with improved transmission performance.This routing strategy,without deviating from the shortest-path routing strategy in the length of paths too much,produces improved performance indexes such as critical generating rate,average length of paths and average search information.
An Approach to Optical Network Design using General Heuristic Optimization Framework
Directory of Open Access Journals (Sweden)
Marko Lacković
2010-12-01
Full Text Available The article tackles the problem of optimization methods in optical network design process, based on optimal traffic routing with the goal to minimize the utilized network resources for given topology and traffic demands. An optimization framework Nyx has been developed with the focus on flexibility in solving optimization problems by implementing general heuristic search techniques. Nyx modular organization has been described, including coding types for solutions and genetic algorithm as the optimization method. Optimal routing has been implemented to demonstrate the use of Nyx in the optical network design process. Optimal routing procedure has been applied to Pan-European optical network with variations of routing procedures and the number of wavelengths. The analysis included no protection scenario, 1+1 protection and path restoration. The routing was performed using shortest path routing and optimal routing which minimizes the use of optical network resources, being network multiplexers, amplifiers and fibers.
ROUTING ALGORITHM FOR THE ROTATION-EXCHANGE NETWORK
Institute of Scientific and Technical Information of China (English)
Chen Baoxing; Xiao Wenjun
2005-01-01
The paper proposes a new routing algorithm for the Rotation-Exchange (REn) network. The length of the path between any two nodes given by the algorithm is not more than (3/8)n2 + O(n), that is, the diameter of REa is not more than (3/8)n2 + O(n). This improves on a (1/2)n2 + O(n) routing algorithm proposed earlier.
Shortest Path Computation with No Information Leakage
Mouratidis, Kyriakos
2012-01-01
Shortest path computation is one of the most common queries in location-based services (LBSs). Although particularly useful, such queries raise serious privacy concerns. Exposing to a (potentially untrusted) LBS the client's position and her destination may reveal personal information, such as social habits, health condition, shopping preferences, lifestyle choices, etc. The only existing method for privacy-preserving shortest path computation follows the obfuscation paradigm; it prevents the LBS from inferring the source and destination of the query with a probability higher than a threshold. This implies, however, that the LBS still deduces some information (albeit not exact) about the client's location and her destination. In this paper we aim at strong privacy, where the adversary learns nothing about the shortest path query. We achieve this via established private information retrieval techniques, which we treat as black-box building blocks. Experiments on real, large-scale road networks assess the pract...
Research of multi-path routing based on network coding in space information networks
Directory of Open Access Journals (Sweden)
Yu Geng
2014-06-01
Full Text Available A multi-path routing algorithm based on network coding is proposed for combating long propagation delay and high bit error rate of space information networks. On the basis of traditional multi-path routing, the algorithm uses a random linear network coding strategy to code data packets. Code number is determined by the next hop link status and the number of current received packets sent by the upstream node together. The algorithm improves retransmission and cache mechanisms through using redundancy caused by network coding. Meanwhile, the algorithm also adopts the flow distribution strategy based on time delay to balance network load. Simulation results show that the proposed routing algorithm can effectively improve packet delivery rate, reduce packet delay, and enhance network performance.
ACO-Based Routing Algorithm for Cognitive Radio Networks
Directory of Open Access Journals (Sweden)
Peng Huang
2013-01-01
Full Text Available Cognitive Radio Networks (CRNs are an outstanding solution to improve efficiency of spectrum usage. Secondary users in cognitive networks may select from a set of available channels to use provided that the occupancy does not affect the prioritized licensed users. However, CRNs produce unique routing challenges due to the high fluctuation in the available spectrum as well as diverse quality-of-service (QoS requirements. In CRNs, distributed multihop architecture and time varying spectrum availability are some of the key factors in design of routing algorithms. In this paper, we develop an ant-colony-optimization- (ACO- based on-demand cognitive routing algorithm (ACO-OCR, jointly consider path and spectrum scheduling, and take advantage of the availability of multiple channels, to improve the delivery latency and packet loss rate. Then, an analytical framework based on M/G/1 queuing theory is introduced to illustrate the relay node queuing model. The performances of ACO-OCR have been evaluated by means of numerical simulations, and the experimental results confirm its effectiveness. Simulation results show that ACO-OCR outperforms other routing approaches in end-to-end path latency and package loss rate.
PCB Drill Path Optimization by Combinatorial Cuckoo Search Algorithm
Directory of Open Access Journals (Sweden)
Wei Chen Esmonde Lim
2014-01-01
Full Text Available Optimization of drill path can lead to significant reduction in machining time which directly improves productivity of manufacturing systems. In a batch production of a large number of items to be drilled such as printed circuit boards (PCB, the travel time of the drilling device is a significant portion of the overall manufacturing process. To increase PCB manufacturing productivity and to reduce production costs, a good option is to minimize the drill path route using an optimization algorithm. This paper reports a combinatorial cuckoo search algorithm for solving drill path optimization problem. The performance of the proposed algorithm is tested and verified with three case studies from the literature. The computational experience conducted in this research indicates that the proposed algorithm is capable of efficiently finding the optimal path for PCB holes drilling process.
PCB drill path optimization by combinatorial cuckoo search algorithm.
Lim, Wei Chen Esmonde; Kanagaraj, G; Ponnambalam, S G
2014-01-01
Optimization of drill path can lead to significant reduction in machining time which directly improves productivity of manufacturing systems. In a batch production of a large number of items to be drilled such as printed circuit boards (PCB), the travel time of the drilling device is a significant portion of the overall manufacturing process. To increase PCB manufacturing productivity and to reduce production costs, a good option is to minimize the drill path route using an optimization algorithm. This paper reports a combinatorial cuckoo search algorithm for solving drill path optimization problem. The performance of the proposed algorithm is tested and verified with three case studies from the literature. The computational experience conducted in this research indicates that the proposed algorithm is capable of efficiently finding the optimal path for PCB holes drilling process.
QOS-BASED MULTICAST ROUTING OPTIMIZATION ALGORITHMS FOR INTERNET
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
Most of the multimedia applications require strict Quality-of-Service (QoS) guarantee during the communication between a single source and multiple destinations. The paper mainly presents a QoS Multicast Routing algorithms based on Genetic Algorithm (QMRGA). Simulation results demonstrate that the algorithm is capable of discovering a set of QoS-based near optimized, non-dominated multicast routes within a few iterations, even for the networks environment with uncertain parameters.
Directory of Open Access Journals (Sweden)
Arief Ameir Rahman Setiawan
2016-07-01
Full Text Available Innovation is one of the most critical issues in research institutions which can be performed through certain routes within the technology transfer mechanism. As the demands of research implementation are increasing, a better mechanism should be deployed to foster innovation. This study will investigate the possibilities for technology transfer mechanism improvements by (i identifying a number of steps required for innovation; (ii measuring the efficiency of each step; and (iii exploring the most efficient routes to innovate through the Dijkstra algorithm. Cases of research on essential oils and derivatives in the Research Center for Chemistry (RCC of the Indonesian Institute of Sciences (LIPI will be examined as the working example for the study. As a result of this study, a model containing a recommended sequence for the most efficient steps to innovation can be proposed. Using the proposed model, the efficiency rate of the technology transfer mechanism was increased twice, suggesting the possibility of stimulating innovation performance.
Institute of Scientific and Technical Information of China (English)
覃德泽
2011-01-01
提出一种基于模拟退火的优化算法来解决路由问题.模拟退火算法以加权累积期望传输时间为代价函数来寻找最佳路由方式.系统仿真基于802.11无线网络,分别比较使用基于模拟退火的路由算法和最短路由算法情况下的网络吞吐量和丢包率.仿真结果显示,基于模拟退火的路由算法比最短路由算法具有更好的性能.%An optimization algorithm based on simulated annealing was proposed to solve the routing problem. The simulated annealing (SA) algorithm looked for the best routing strategy by taking the weighted cumulative expectations transmission time as the cost function. The simulation that operated based on 802. 11 wireless networks compared the network throughput and the packet loss ratio by using SA-based routing algorithm and the shortest path routing strategy respectively. The results show that SA-based routing algorithm had a better performance than that of the shortest path routing algorithm.
Provide a method to Prediction of nodes movement to optimize Routing Algorithms in Ad Hoc Networks
Directory of Open Access Journals (Sweden)
E.jahani
2012-06-01
Full Text Available Ad hoc networks have been of great interest among scholars of the field, due to their flexibility, quick setup,high potentiality, and also their application in the battle field, fire, earthquakes, where there is no hope to setup infrastructure networks. network dynamic, high mobility of nodes, the nature of broadcast communication ,shortdurability of mobile devices batteries, transmission errors and as a result packet loss and limited bandwidth of bands, all cause the routing in those networks to be more difficult than the other networks.
Institute of Scientific and Technical Information of China (English)
Chen Kaiyan; Si Junhong; Zhou Fubao; Zhang Renwei; Shao He; Zhao Hongmei
2015-01-01
In mine ventilation networks, the reasonable airflow distribution is very important for the production safety and economy. Three basic problems of the natural, full-controlled and semi-controlled splitting were reviewed in the paper. Aiming at the high difficulty semi-controlled splitting problem, the general nonlinear multi-objectives optimization mathematical model with constraints was established based on the theory of mine ventilation networks. A new algorithm, which combined the improved differential evaluation and the critical path method (CPM) based on the multivariable separate solution strategy, was put forward to search for the global optimal solution more efficiently. In each step of evolution, the feasible solutions of air quantity distribution are firstly produced by the improved differential evolu-tion algorithm, and then the optimal solutions of regulator pressure drop are obtained by the CPM. Through finite steps iterations, the optimal solution can be given. In this new algorithm, the population of feasible solutions were sorted and grouped for enhancing the global search ability and the individuals in general group were randomly initialized for keeping diversity. Meanwhile, the individual neighbor-hood in the fine group which may be closely to the optimal solutions were searched locally and slightly for achieving a balance between global searching and local searching, thus improving the convergence rate. The computer program was developed based on this method. Finally, the two ventilation networks with single-fan and multi-fans were solved. The results show that this algorithm has advantages of high effectiveness, fast convergence, good robustness and flexibility. This computer program could be used to solve large-scale generalized ventilation networks optimization problem in the future.
An Improved Wireless Sensor Network Routing Algorithm
Institute of Scientific and Technical Information of China (English)
Shengmei Luo; Xue Li; Yiai Jin; Zhixin Sun
2015-01-01
High performance with low power consumption is an essential factor in wireless sensor networks (WSN). In order to address the issue on the lifetime and the consumption of nodes in WSNs, an improved ad hoc on⁃demand distance vector rout⁃ing (IAODV) algorithm is proposed based on AODV and LAR protocols. This algorithm is a modified on⁃demand routing al⁃gorithm that limits data forwarding in the searching domain, and then chooses the route on basis of hop count and power consumption. The simulation results show that the algorithm can effectively reduce power consumption as well as prolong the network lifetime.
Packet routing algorithm for polar orbit LEO satellite constellation network
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
Broadband satellite networks are capable of providing global coverage and support various services. The networks constructed by Low Earth Orbit (LEO) satellite constellations have attracted great interests because of their short round-trip delays and wide bandwidths. A challenging problem is to develop a simple and efficient packet routing algorithm for the LEO satellite constellation network. This paper presents a SpiderWeb Topological Network (SWTN) and a distributed packet routing algorithm for the LEO satellite constellation network based on the SWTN. The algorithm gives the minimum propagation delay paths with low computational complexity and requires no routing tables, which is practical for on-board processing. The performance of the algorithm is demonstrated through simulations.
Optimizing on multiple constrained QoS multicast routing algorithms based on GA
Institute of Scientific and Technical Information of China (English)
孙宝林; 李腊元
2004-01-01
With the rapid development of Internet, mobile networks and high-performance networking technology,multiple constrained QoS multicast routing optimization in networks with uncertain parameters has become a very important research issue in the areas of networks and distributed systems. It is also a challenging and hard problem to the next generation Internet and high-performance networks, and has attracted the interests of many people. This paper discusses the multiple constrained QoS multicast routing problem, which may deal with the delay, delay jitter,bandwidth and packet loss metrics, and describes a network model for researching the routing problem. The paper mainly presents multiple constrained QoS multicast routing algorithm (MCQMRA), a QoS multicast routing policy for Internet,mobile network or other high-performance networks, which is based on the genetic algorithm (GA) and can provide QoS-sensitive paths in a scalable and flexible wayin the network environment with uncertain parameters. The MCQMRA can also optimize the network resources such as bandwidth, delay, packet loss metrics and can converge to the optimal or near-optimal solution within few iterations, even for the network environment with uncertain parameters. Simulation results show that MCQMRA is an available approach to QoS multicast routing decision.
Quality-of-Service Routing Using Path and Power Aware Techniques in Mobile Ad Hoc Networks
Directory of Open Access Journals (Sweden)
R. Asokan
2008-01-01
Full Text Available Mobile ad hoc network (MANET is a collection of wireless mobile hosts dynamically forming a temporary network without the aid of any existing established infrastructure. Quality of service (QoS is a set of service requirements that needs to be met by the network while transporting a packet stream from a source to its destination. QoS support MANETs is a challenging task due to the dynamic topology and limited resources. The main objective of this paper is to enhance the QoS routing for MANET using temporally ordered routing algorithm (TORA with self-healing and optimized routing techniques (SHORT. SHORT improves routing optimality by monitoring routing paths continuously and redirecting the path whenever a shortcut path is available. In this paper, the performance comparison of TORA and TORA with SHORT has been analyzed using network simulator for various parameters. TORA with SHORT enhances performance of TORA in terms of throughput, packet loss, end-to-end delay, and energy.
Directory of Open Access Journals (Sweden)
Sunil Kumar,
2010-12-01
Full Text Available Wireless sensor network is tremendously being used in different environments to perform various monitoring task such as search, rescue, disaster relief, target tracking and a number of tasks in smart environment. In this paper a unique localization algorithm is proposed that gives the high accuracy in wireless sensor network. We propose amobile beacon algorithm and then merge it with DV- hop algorithm to introduce a unique approach which solves the localization problem in wireless sensor network.
Study of network survivability based on multi-path routing mechanism
Institute of Scientific and Technical Information of China (English)
HUANG Song; XU Yong; ZHANG Ling
2008-01-01
As an important secure routing mechanism, multi-path routing is one of the major ways to improve network efficiency and to guarantee the network security, which ensures the reliability of data transmission by using backup paths when the pri mary one is unavailable due to local node or link failures. Most current studies on multi-path routing mechanism are based on experiments or simulations. The re sults are usually specific application scenarios oriented heuristic algorithms, lacking universal significance. In this paper, a theoretic analysis is performed on the relationship between the multi-path routing policy, the network efficiency and its survivability. Starting with point-to-point communication network, an impact oriented analysis is made on the network interference under multi-path routing mechanism. Based on the analysis, the upper-limit of network performance under interference impact is also discussed.
Routing algorithms in networks-on-chip
Daneshtalab, Masoud
2014-01-01
This book provides a single-source reference to routing algorithms for Networks-on-Chip (NoCs), as well as in-depth discussions of advanced solutions applied to current and next generation, many core NoC-based Systems-on-Chip (SoCs). After a basic introduction to the NoC design paradigm and architectures, routing algorithms for NoC architectures are presented and discussed at all abstraction levels, from the algorithmic level to actual implementation. Coverage emphasizes the role played by the routing algorithm and is organized around key problems affecting current and next generation, many-core SoCs. A selection of routing algorithms is included, specifically designed to address key issues faced by designers in the ultra-deep sub-micron (UDSM) era, including performance improvement, power, energy, and thermal issues, fault tolerance and reliability. · Provides a comprehensive overview of routing algorithms for Networks-on-Chip and NoC-based, manycore systems; · Describe...
无线传感器网络中能量多路径路由算法的研究%Research on Energy Multi-path Routing Algorithm for Wirelss Sensor Networks
Institute of Scientific and Technical Information of China (English)
李琴
2014-01-01
能量多路径路由算法考虑了通信路径上的能量消耗和剩余能量，节点根据概率选择下一跳节点。改进算法在原有算法的基础上加入了路由跳数控制，实验仿真结果表明根据改进算法所获得的传输路径跳数和传输能耗明显减少，延长了网络生命周期。由于无线传感器网络是动态变化的，文章最后提出了动态跳数限制的想法以期能够更好的适应传感器网络，选择最优路径。%Energy multi-path routing algorithm considers energy consumption and residual energy on the communication path, node based on the probability to select the next hop node. Improved algorithm adds the control of routing hops, Simulation proof Improved algorithm select a smaller number of hops to extend the network life cycle. Wireless sensor network is dynamic, in the end we put up dynamic hop count limit in order to adapt to WSN and select the optimal path.
Institute of Scientific and Technical Information of China (English)
HEWei; YANGSuqiong; YUANBaozong; LINBiqin
2004-01-01
Shortest path search has important practical applications and is related to optimization problem.This paper discusses a new algorithm time-synchronous heuristic dynamic programming search, which combined the pruning and global optimization of DP (Dynamic programming) and the partial search of heuristic strategy and found the shortest path in time O(n/kd) (k, d ≥ 1). Furthermore, the algorithm can be applied to find the K shortest paths between a pair of given nodes or all paths less than a given length within the same steps. Finally this algorithm was applied to the shortest path search on the real map and user could use spoken dialog to query shortcut in realtime, 90% of the system responses are correct.
Directory of Open Access Journals (Sweden)
Xiaoming Wu
2015-01-01
Full Text Available Recent studies have shown that mobile sink can be a solution to solve the problem that energy consumption of sensor nodes is not balanced in wireless sensor networks (WSNs. Caused by the sink mobility, the paths between the sensor nodes and the sink change frequently and have profound influence on the lifetime of WSN. It is necessary to design a protocol that can find efficient routings between the mobile sink and nodes but does not consume too many network resources. In this paper, we propose a swarm intelligent algorithm based route maintaining protocol to resolve this issue. The protocol utilizes the concentric ring mechanism to guide the route researching direction and adopts the optimal routing selection to maintain the data delivery route in mobile sink WSN. Using the immune based artificial bee colony (IABC algorithm to optimize the forwarding path, the routing maintaining protocol could find an alternative routing path quickly and efficiently when the coordinate of sink is changed in WSN. The results of our extensive experiments demonstrate that our proposed route maintaining protocol is able to balance the network traffic load and prolong the network lifetime.
Wang, Xuewu; Shi, Yingpan; Ding, Dongyan; Gu, Xingsheng
2016-02-01
Spot-welding robots have a wide range of applications in manufacturing industries. There are usually many weld joints in a welding task, and a reasonable welding path to traverse these weld joints has a significant impact on welding efficiency. Traditional manual path planning techniques can handle a few weld joints effectively, but when the number of weld joints is large, it is difficult to obtain the optimal path. The traditional manual path planning method is also time consuming and inefficient, and cannot guarantee optimality. Double global optimum genetic algorithm-particle swarm optimization (GA-PSO) based on the GA and PSO algorithms is proposed to solve the welding robot path planning problem, where the shortest collision-free paths are used as the criteria to optimize the welding path. Besides algorithm effectiveness analysis and verification, the simulation results indicate that the algorithm has strong searching ability and practicality, and is suitable for welding robot path planning.
comparative analysis and implementation of dijkstra's shortest path ...
African Journals Online (AJOL)
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Graphs provide the ultimate in data structure flexibility, because they can ...... 3312-3323, 2012. [28] Schaffer ... International. Conference on Mechanic Automation and Control ... Proceedings of the Third International Symposium on Computer ...
AN APPROACH TO OPTIMIZE QOS ROUTING PROTOCOL USING GENETIC ALGORITHM IN MANET
Directory of Open Access Journals (Sweden)
Vikas Siwach
2012-09-01
Full Text Available Quality of Service support for Mobile Ad hoc Networks is an exigenttask due to dynamic topology and limited resource. To support QoS,the link state information such as delay, bandwidth, jitter, cost, errorrate and node energy in the network should be available andmanageable. QOS is one the basic requirement of a network andwhen we talk about the Mobile Network this is the highly constraintrequirement of a user. To improve the quality of service we usedifferent changes in MANET protocols, its parameter, routingalgorithm etc. The proposed work is to define a genetic based routingapproach to optimize the routing in MANETs. The genetic approachwill generate an optimized path on the basic of congestion over thenetwork. The result path will improve the data delivery over thenetwork. The focus of the paper is to study about MANET, QOS andtries to develop a network on which genetic algorithm is applied togenerate an optimized path.
Drilling Path Optimization Based on Particle Swarm Optimization Algorithm
Institute of Scientific and Technical Information of China (English)
ZHU Guangyu; ZHANG Weibo; DU Yuexiang
2006-01-01
This paper presents a new approach based on the particle swarm optimization (PSO) algorithm for solving the drilling path optimization problem belonging to discrete space. Because the standard PSO algorithm is not guaranteed to be global convergence or local convergence, based on the mathematical algorithm model, the algorithm is improved by adopting the method of generate the stop evolution particle over again to get the ability of convergence to the global optimization solution. And the operators are improved by establishing the duality transposition method and the handle manner for the elements of the operator, the improved operator can satisfy the need of integer coding in drilling path optimization. The experiment with small node numbers indicates that the improved algorithm has the characteristics of easy realize, fast convergence speed, and better global convergence characteristics, hence the new PSO can play a role in solving the problem of drilling path optimization in drilling holes.
Intelligent Routing using Ant Algorithms for Wireless Ad Hoc Networks
Directory of Open Access Journals (Sweden)
S. Menaka
2013-08-01
Full Text Available Wireless network is one of the niche areas and has been a growing interest owing to their ability to control the physical environment even from remote locations. Intelligent routing, bandwidth allocation and power control techniques are the known critical factors for this network communication. It is customary to find a feasible path between the communication end point which is a challenging task in this type of network. The present study proposes an Ant Mobility Model (AMM, an on-demand, multi-path routing algorithm that exercises power control and coordinate the nodes to communicate with one another in wireless network. The main goal of this protocol is to reduce the overhead, congestion, and stagnation, while increasing the throughput of the network. It can be realized from the simulation results that AMM proves to be a promising solution for the mobility pattern in wireless networks like MANETs.
IPv6 Network Mobility Route Optimization Survey
Directory of Open Access Journals (Sweden)
Samer S. Hassan
2011-01-01
Full Text Available Problem statement: This study describes that the Next Generation of Networks (NGN communication will supports multiple technologies, handles the mobility of end users to move through heterogeneous access networks, with ability to connect to different networks. Where the Internet Engineer Task Force maintain (IETF the Mobile IPv6 (MIPv6 to handles the mobility of networks (NEMO, to provide wide band and more scalable network services. One of the MIPv6 built-in features is Route Optimization (RO to solve the inefficient route problem. Conclusion/Recommendations: The main objective of this article is to survey, classify and make a compression between the available schemes for route optimization over the last years depends on the basic criteria generated from the published articles within different network topology. This article presents the problem of suboptimal route which is further increased with increasing of nesting levels and there is no such one scheme is perfect for all network environments.
Cost allocation in shortest path games
Voorneveld, M.; Grahn, S.
2001-01-01
A class of cooperative games arising from shortest path problems is dened These shortest path games are shown to be totally balanced and allow a population monotonic allocation scheme Possible methods for obtaining core elements are indicated rst by relating to the allocation rules in taxation and b
Institute of Scientific and Technical Information of China (English)
卢江波; 方志
2016-01-01
动态网络最短路径射线追踪算法中的向后追踪方法能够解决线性走时插值算法(LTI)向后追踪过程不稳定的问题，但是其计算效率较低。综合利用节点次级源的位置信息以及波的传播规律，提出了改进方法，排除了动态网络最短路径射线追踪算法向后追踪过程中存在的大量冗余计算。数值算例表明，改进的向后追踪方法具有较高的计算效率，是动态网络最短路径射线追踪算法中向后追踪方法的几倍至几十倍；若将改进后的向后追踪方法应用于动态网络最短路径射线追踪改进算法，则该算法的计算效率将提高一倍左右。%The backward tracing method of the shortest path ray tracing algorithm with dynamic net-works can solve the unstability problem in the backward tracing procedure of the LTI (Linear Travel-time Interpolation)algorithm,but the computational efficiency of the method is low.This study presented an improved method on backward tracing.According to the location information of the secondary sources for the nodes and the law of wave propagation,a large number of redundancy calculation are excluded in the backward tracing of the dynamic networks tracing algorithm.The numerical examples show that the im-proved method exhibits the higher computational efficiency.The calculation efficiency of the improved method is several times that of the backward tracing method of the dynamic networks tracing algorithm. When the improved method is applied to the improved algorithm of the shortest path ray tracing with dy-namic networks,the computational efficiency of the algorithm can be increased by about 100 %.
The Shortest Path Problems in Battery-Electric Vehicle Dispatching with Battery Renewal
Directory of Open Access Journals (Sweden)
Minfang Huang
2016-06-01
Full Text Available Electric vehicles play a key role for developing an eco-sustainable transport system. One critical component of an electric vehicle is its battery, which can be quickly charged or exchanged before it runs out. The problem of electric vehicle dispatching falls into the category of the shortest path problem with resource renewal. In this paper, we study the shortest path problems in (1 electric transit bus scheduling and (2 electric truck routing with time windows. In these applications, a fully-charged battery allows running a limited operational distance, and the battery before depletion needs to be quickly charged or exchanged with a fully-charged one at a battery management facility. The limited distance and battery renewal result in a shortest path problem with resource renewal. We develop a label-correcting algorithm with state space relaxation to find optimal solutions. In the computational experiments, real-world road geometry data are used to generate realistic travel distances, and other types of data are obtained from the real world or randomly generated. The computational results show that the label-correcting algorithm performs very well.
Multicast Routing Problem Using Tree-Based Cuckoo Optimization Algorithm
Directory of Open Access Journals (Sweden)
Mahmood Sardarpour
2016-06-01
Full Text Available The problem of QoS multicast routing is to find a multicast tree with the least expense/cost which would meet the limitations such as band width, delay and loss rate. This is a NP-Complete problem. To solve the problem of multicast routing, the entire routes from the source node to every destination node are often recognized. Then the routes are integrated and changed into a single multicast tree. But they are slow and complicated methods. The present paper introduces a new tree-based optimization method to overcome such weaknesses. The recommended method directly optimizes the multicast tree. Therefore a tree-based typology including several spanning trees is created which combines the trees two by two. For this purpose, the Cuckoo Algorithm is used which is proved to be well converged and makes quick calculations. The simulation conducted on different types of network typologies proved that it is a practical and influential algorithm.
An anticipation mechanism for the shortest path problem based on Physarum polycephalum
Wang, Qing; Lu, Xi; Zhang, Xiaoge; Deng, Yong; Xiao, Can
2015-04-01
In this paper, we put forward an anticipation mechanism for the existing Physarum-inspired shortest path finding method. The Physarum-based shortest path finding model can be implemented by an iterative algorithm and has wide applications in many fundamental network optimization problems. In this paper, we mainly focus on the Physarum-inspired shortest path tree model. Normally, we stop the program when the difference between two consecutive iterations is less than a predefined threshold. However, we do not know how to set the specific value for the threshold variable. In order to find out the optimal solution, we need to set the threshold as a very small number. This in turn will consume a lot of time. From this point of view, this algorithm lacks an efficient and reliable mechanism to judge when the optimal solution will be found. In this paper, we introduce an anticipation mechanism to address this issue. Numerical examples are used to demonstrate its reliability and efficiency.
Multiple-Source Shortest Paths in Embedded Graphs
Cabello, Sergio; Erickson, Jeff
2012-01-01
Let G be a directed graph with n vertices and non-negative weights in its directed edges, embedded on a surface of genus g, and let F be an arbitrary face of G. We describe an algorithm to preprocess the graph in O(gn log n) time, so that the shortest-path distance from any vertex on the boundary of F to any other vertex in G can be retrieved in O(log n) time. Our result directly generalizes the O(n log n)-time algorithm of Klein [SODA 2005] for multiple-source shortest paths in planar graphs. Intuitively, our preprocessing algorithm maintains a shortest-path tree as its source point moves continuously around the boundary of F. As an application of our algorithm, we describe algorithms to compute a shortest non-contractible or non-separating cycle in embedded, undirected graphs in O(g^2 n log n) time.
Fault Tolerant Multi-Criteria Multi-Path Routing in Wireless Sensor Networks
Directory of Open Access Journals (Sweden)
Koffka Khan
2015-05-01
Full Text Available The Ad Hoc On-Demand Multi-Path Distance Vector (AOMDV routing protocol allows the transport of data along one or more paths in wireless sensor networks (WSNs. The path chosen is based on a single shortest path hop count metric. The data on some WSNs is mission critical, for example, military and health care applications. Hence, fault tolerance in WSNs is becoming increasingly important. To improve the fault tolerance of WSNs in lossy environments, this work adds to the AOMDV routing protocol as it incorporates an additional packet loss metric. This Multi-criteria AOMDV or M-AOMDV is evaluated using the ns2 simulator. Simulations show that M-AOMDV maintains relatively low packet loss rates when the WSN is experiencing loss.
Multiple constraints QoS multicast routing optimization algorithm in MANET based on GA
Institute of Scientific and Technical Information of China (English)
Baolin Sun; Shangchao Pi; Chao Gui; Yue Zeng; Bing Yan; Wenxiang Wang; Qianqing Qin
2008-01-01
Usually multiple quality of service (QoS) guarantees are required in most multicast applications. This paper presents a multiple constraints algorithm for multicast traffic engineering in mobile ad hoc networks (MANET). The proposed algorithm is a new version of multiple constraints QoS multicast routing optimization algorithm in MANET based on genetic algorithm (MQMGA). The proposed MQMGA can optimize the maximum link utilization, the cost of the multicast tree, the selection of the long-life path, the average delay and the maximum end-to-end delay. Experimental result shows that the approach is efficient, has promising performance in multicast traffic engineering and for evaluating the route stability in dynamic mobile networks.
Yuan, Fei; Zhou, You; Wang, Meng; Yang, Jing; Wu, Kai; Lu, Changhong; Kong, Xiangyin; Cai, Yu-Dong
2015-01-01
Prostate cancer is a type of cancer that occurs in the male prostate, a gland in the male reproductive system. Because prostate cancer cells may spread to other parts of the body and can influence human reproduction, understanding the mechanisms underlying this disease is critical for designing effective treatments. The identification of as many genes and chemicals related to prostate cancer as possible will enhance our understanding of this disease. In this study, we proposed a computational method to identify new candidate genes and chemicals based on currently known genes and chemicals related to prostate cancer by applying a shortest path approach in a hybrid network. The hybrid network was constructed according to information concerning chemical-chemical interactions, chemical-protein interactions, and protein-protein interactions. Many of the obtained genes and chemicals are associated with prostate cancer. PMID:26504486
LBR: Load Balancing Routing Algorithm for Wireless Sensor Networks
Daabaj, Khaled; Dixon, Mike; Koziniec, Terry
2010-06-01
Homogeneous wireless sensor networks (WSNs) are organized using identical sensor nodes, but the nature of WSNs operations results in an imbalanced workload on gateway sensor nodes which may lead to a hot-spot or routing hole problem. The routing hole problem can be considered as a natural result of the tree-based routing schemes that are widely used in WSNs, where all nodes construct a multi-hop routing tree to a centralized root, e.g., a gateway or base station. For example, sensor nodes on the routing path and closer to the base station deplete their own energy faster than other nodes, or sensor nodes with the best link state to the base station are overloaded with traffic from the rest of the network and experience a faster energy depletion rate than their peers. Routing protocols for WSNs are reliability-oriented and their use of reliability metric to avoid unreliable links makes the routing scheme worse. However, none of these reliability oriented routing protocols explicitly uses load balancing in their routing schemes. Since improving network lifetime is a fundamental challenge of WSNs, we present, in this chapter, a novel, energy-wise, load balancing routing (LBR) algorithm that addresses load balancing in an energy efficient manner by maintaining a reliable set of parent nodes. This allows sensor nodes to quickly find a new parent upon parent loss due to the existing of node failure or energy hole. The proposed routing algorithm is tested using simulations and the results demonstrate that it outperforms the MultiHopLQI reliability based routing algorithm.
Multimedia Traffic Routing in Multilayer WDM Networks
Amphawan, Angela; Hasan, Hassanuddin
2012-01-01
The advent of real-time multimedia services over the Internet has stimulated new technologies for expanding the information carrying capacity of optical network backbones. Multilayer wavelength division multiplexing (WDM) packet switching is an emerging technology for increasing the bandwidth of optical networks. Two algorithms for the routing of the multimedia traffic flows were applied: (i) Capacitated Shortest Path First (CSPF) routing, which minimizes the distance of each flow linking the given source and destination nodes and satisfying capacity constraints; and (ii) Flow Deviation Algorithm (FDA) routing, which minimizes the network?wide average packet delay.
Electric Vehicle Routing Problem with Charging Time and Variable Travel Time
Directory of Open Access Journals (Sweden)
Sai Shao
2017-01-01
Full Text Available An electric vehicle routing problem with charging time and variable travel time is developed to address some operational issues such as range limitation and charging demand. The model is solved by using genetic algorithm to obtain the routes, the vehicle departure time at the depot, and the charging plan. Meanwhile, a dynamic Dijkstra algorithm is applied to find the shortest path between any two adjacent nodes along the routes. To prevent the depletion of all battery power and ensure safe operation in transit, electric vehicles with insufficient battery power can be repeatedly recharged at charging stations. The fluctuations in travel time are implemented to reflect a dynamic traffic environment. In conclusion, a large and realistic case study with a road network in the Beijing urban area is conducted to evaluate the model performance and the solution technology and analyze the results.
Improved approximations for robust mincut and shortest path
Polishchuk, Valentin
2010-01-01
In two-stage robust optimization the solution to a problem is built in two stages: In the first stage a partial, not necessarily feasible, solution is exhibited. Then the adversary chooses the "worst" scenario from a predefined set of scenarios. In the second stage, the first-stage solution is extended to become feasible for the chosen scenario. The costs at the second stage are larger than at the first one, and the objective is to minimize the total cost paid in the two stages. We give a 2-approximation algorithm for the robust mincut problem and a ({\\gamma}+2)-approximation for the robust shortest path problem, where {\\gamma} is the approximation ratio for the Steiner tree. This improves the factors (1+\\sqrt2) and 2({\\gamma}+2) from [Golovin, Goyal and Ravi. Pay today for a rainy day: Improved approximation algorithms for demand-robust min-cut and shortest path problems. STACS 2006]. In addition, our solution for robust shortest path is simpler and more efficient than the earlier ones; this is achieved by a...
Countering Count-To-Infinity in High Speed Networks
Directory of Open Access Journals (Sweden)
Y. Kiran
2013-01-01
Full Text Available Routing tables of all the routers needs frequent updates due topology changes resulting because of link failures or link metric modifications. Each of those updates may cause transient routing loops. These loops pose significant stability problems in Wireless Networks. Distributed routing algorithms capable of avoiding such transient loops in network path are deemed efficient. Some earlier approaches like Shortest path routing (Dijkstra etc. have problems maintaining the balance between node delays and link delays. Besides an earlier algorithm, Distributed Path Computation with Intermediate Variables (DIV guarantees steady-state, with no transient loops. It’s ability to operate with existing distributed routing algorithms to guarantee that the directed graph induced by the routing decisions stays acyclic by implementing an update mechanism using simple message exchanges between neighboring nodes that guarantees loop freedom at all times. It outperforms existing loop prevention algorithms in several key metrics such as frequency of synchronous updates and the ability to maintain paths during transitions. But still frequency of updates is still an open issue and we address that problem specifically by implementing and using proactive source routing (PSR protocol. Compared to existing routing protocols,It requires no timestamp for routing updates. In PSR the update messages are easily integrated into the tree structure, so that the computation overhead can be significantly reduced.
ZigBee Network Routing Algorithm's Optimization%ZigBee网络路由算法改进优化
Institute of Scientific and Technical Information of China (English)
卢涛; 魏绍亮; 徐秀秀
2015-01-01
为提高ZigBee网络的生存周期和数据传输的可靠性，研究人员在ZigBee网络原有路由算法的基础上做了许多改进。但是这些改进都只是单一考虑节点或者能量因素，没有考虑网络节点之间信道质量因素，这造成了因网络信道链路质量差引起的网络生存周期减少，网络传输可靠性降低等一系列问题。本文结合原有路由算法和相关改进算法的不足，在某一改进算法的基础上引入信道链路质量LQI。改进后，路由算法不再单一包括节点或者能量因素，而是同时考虑节点能量和网络信道质量LQI两方面因素。试验模拟的结果表明，该算法能在相同条件下，比较传统的路由算法和相关改进，在网络生存周期和网络传输可靠性方面均有所提高。%In order to improve the lifetime of ZigBee network and data transmission’s reliability, researchers has done a lot of improvement based on the original ZigBee network routing algorithm. But these improvements just considered the single node or energy, without considering the channel quality factors between network nodes. This has resulted in a reduction of the network lifetime and transmission reliability and because of the poor network channel link quality. This paper combined with the shortage of original routing algorithms and related improved algorithm, introduced the channel link quality LQI on the basis of a improved algorithm. After improvements, the routing algorithm is not only including the node or energy factor, but also considering both node energy and channel quality LQI. The experimental simulation’s result shows that under the same conditions, compared to the traditional routing algorithms and related improvements, this algorithm improved network’s lifetime and transmission reliability.
Genetic based optimization for multicast routing algorithm for MANET
Indian Academy of Sciences (India)
C Rajan; N Shanthi
2015-12-01
Mobile Ad hoc Network (MANET) is established for a limited period, for special extemporaneous services related to mobile applications. This ad hoc network is set up for a limited period, in environments that change with the application. While in Internet the TCP/IP protocol suite supports a wide range of application, in MANETs protocols are tuned to specific customer/application. Multicasting is emerging as a popular communication format where the same packet is sent to multiple nodes in a network. Routing in multicasting involves maintaining routes and finding new node locations in a group and is NP-complete due to the dynamic nature of the network. In this paper, a Hybrid Genetic Based Optimization for Multicast Routing algorithm is proposed. The proposed algorithm uses the best features of Genetic Algorithm (GA) and particle swarm optimization (PSO) to improve the solution. Simulations were conducted by varying number of mobile nodes and results compared with Multicast AODV (MAODV) protocol, PSO based and GA based solution. The proposed optimization improves jitter, end to end delay and Packet Delivery Ratio (PDR) with faster convergence.
Institute of Scientific and Technical Information of China (English)
冯奇; 周雪忠; 黄厚宽; 张小平
2011-01-01
Trial-based value iteration is a class of efficient algorithms to solve partially observable Markov decision process (POMDP), among which FSVI is one of the fastest algorithms. But the overhead of computing MDP value function by FSVI is not negligible for large-scale POMDP problems. In this paper, we propose a new value iteration method based on the shortest Hamiltonian path (shortest Hamiltonian path-based value iteration, SHP-VI). This method explores an optimal belief trajectory using the shortest Hamiltonian path resulting from ant colony optimization, and updates value function over the encountered belief states in reversed order. Compared with FSVI, the experimental results show that SHP-VI accelerates the computation of belief trajectory greatly in trial-based algorithms.%基于试探(trial-based)的值迭代算法是求解部分可观察Markov决策过程(partially observable Markov decision process,POMDP)模型的一类有效算法,其中FSVI算法是目前最快的算法之一.然而对于较大规模的POMDP问题,FSVI计算MDP值函数的时间是不容忽视的.提出一种基于最短哈密顿通路(shortest Hamiltonian path)的值迭代算法(shortest Hamiltonian path-based value iteration,SHP-VI).该方法用求解最短哈密顿通路问题的蚁群算法计算一条最优信念状态轨迹,然后在这些信念状态上反向更新值函数.通过与FSVI算法的实验比较,结果表明SHP-VI算法很大程度地提高了基于试探的算法计算信念状态轨迹的效率.
多核平台并行单源最短路径算法%Parallel Single-source Shortest Path Algorithm on Multi-core Platform
Institute of Scientific and Technical Information of China (English)
黄跃峰; 钟耳顺
2012-01-01
A multi-thread parallel Single-source Shortest Path(SSSP) algorithm is proposed in multi-cores platform. It employs buckets to sort and uses the similar parallel strategy of A-Stepping algorithm. It does edge relaxations of the same bucket in parallel by slave threads, and searches all buckets in sequence by master thread. Experimental results show that this algorithm performs 4 seconds in the USA road network, achieving a higher speedup compared with serial parallel algorithm using same code.%提出一种多核平台并行单源最短路径算法.采用与Δ-Stepping算法相似的并行策略,通过多个子线程对同一个桶中的弧段进行并行松弛,利用主线程控制串行搜索中桶的序列.实验结果表明,该算法求解全美单源最短路径的时间约为4 s,与使用相同代码实现的串行算法相比,加速比更高.
无线传感器网络跳数优化非均衡路由算法%Hop optimized unequal clustering routing algorithm for wireless sensor networks
Institute of Scientific and Technical Information of China (English)
柏荡; 石为人; 高鹏; 谢思佳; 李艳萍
2012-01-01
In multi-hop clustering routing algorithm for wireless sensor networks, nodes close to base station die over quick for heavy traffic load. A hop optimized unequal clustering routing algorithm for wireless sensor networks is proposed. HOUCR establishes routing path based on optimal hop counts to reduce network energy consumption in each round. It forms unequal cluster to realize energy balance and solve the "hop spot" problem. Simulation results show that, HOUCR can reduce and balance network energy consumption, prolong network life-time.%针对多跳层次性路由算法中存在的距离基站较近的节点因数据通信负载过重而导致死亡速度过快的问题,提出一种无线传感器网络跳数优化非均衡路由(Hop Optimized Unequal Clustering Routing,HOUCR)算法.HOUCR建立基于最优跳数的路由路径,减小每回合网络能量消耗;通过能量均衡产生非均衡的簇,解决“热点”问题.仿真实验表明,HOUCR能够减小并均衡网络能量消耗,延长了网络寿命.
New Variants of Ant Colony Optimization for Network Routing
Directory of Open Access Journals (Sweden)
Debasmita Mukherjee
2012-12-01
Full Text Available This paper suggests new variants of Ant Colony Optimization(ACOTechniques for Network Routing. There are three existing variants of ACO based on pheromone deposit calculation. In our earlier work we suggested three different heuristics for selecting the next node at each step of iteration. Incorporation of these heuristics in each of the above three variants result into nine variations. In this paper the performance of these nine variations has been studied. Moreover, we have modified the pheromone deposit calculation considering the transmission time of each successful packet(ant and incorporated this new pheromone update formula in each of the nine variants. As a result, we have obtained nine new variants of ACO. The performance of these new nine variants has been compared with previous ones with respect to the speed of execution, throughput and the number of successful packets. The experiments have been performed over two different network topologies. In one of the variant a tabu list has been incorporated. The length of the tabu list plays a vital role in improving the performance of the routing algorithm. In this paper it has been observed that the new variations of ACO have outperformed the previous ones. These new variants can perform efficient network routing in an environment having variable transmission time along the paths due to congestion or poor link quality.
Neural network and genetic algorithm based global path planning in a static environment
Institute of Scientific and Technical Information of China (English)
DU Xin; CHEN Hua-hua; GU Wei-kang
2005-01-01
Mobile robot global path planning in a static environment is an important problem. The paper proposes a method of global path planning based on neural network and genetic algorithm. We constructed the neural network model of environmental information in the workspace for a robot and used this model to establish the relationship between a collision avoidance path and the output of the model. Then the two-dimensional coding for the path via-points was converted to one-dimensional one and the fitness of both the collision avoidance path and the shortest distance are integrated into a fitness function. The simulation results showed that the proposed method is correct and effective.
Core-based Shared Tree Multicast Routing Algorithms for LEO Satellite IP Networks
Institute of Scientific and Technical Information of China (English)
Cheng Lianzhen; Zhang Jun; Liu Kai
2007-01-01
A new core-based shared tree algorithm, viz core-cluster combination-based shared tree (CCST) algorithm and the weighted version (i.e. w-CCST algorithm) are proposed in order to resolve the channel resources waste problem in typical source-based multicast routing algorithms in low earth orbit (LEO) satellite IP networks. The CCST algorithm includes the dynamic approximate center (DAC)core selection method and the core-cluster combination multicast route construction scheme. Without complicated onboard computation,the DAC method is uniquely developed for highly dynamic networks of periodical and regular movement. The core-cluster combination method takes core node as the initial core-cluster, and expands it stepwise to construct an entire multicast tree at the lowest tree cost by a shortest path scheme between the newly-generated core-cluster and surplus group members, which results in great bandwidth utilization.Moreover, the w-CCST algorithm is able to strike a balance between performance of tree cost and that of end-to-end propagation delay by adjusting the weighted factor to meet strict end-to-end delay requirements of some real-time multicast services at the expense of a slight increase in tree cost. Finally, performance comparison is conducted between the proposed algorithms and typical algorithms in LEO satellite IP networks. Simulation results show that the CCST algorithm significantly decreases the average tree cost against to the others, and also the average end-to-end propagation delay of w-CCST algorithm is lower than that of the CCST algorithm.
A Multicast Routing to Improve Multicast Capacity with Minimal Network Coding Cellsin WDM Networks
Liu, Huanlin; Zhou, Bangtao; Chen, Yong
2014-12-01
Multicast routing based on network coding can save large wavelength channels with high network coding operation costs for the all-optical WDM network. An optical multicast routing algorithm based on minimum network coding cells to reach the multicast max-flow is proposed in the paper. The algorithm selects path in the K shortest paths from source to each destination which meets the two criteria. One is to select paths making the least probability of dropping multicast max-flow. The other is to make the path lowest potential path coding cells in the K shortest paths. We investigate that the previously proposed multicast algorithms based on network coding choose the shortest paths or link-disjoint highest shared links to construct network coding sub-graph which may result in the large coding operation cost and decrease the possibility of getting the maximal multicast flow. The simulation results show that the proposed algorithm can effectively reduce the network coding cells and improve the possibility of achieving the multicast max-flow by using our designed two path selection criteria. In addition, the proposed multicast algorithm deteriorates a very limited multicast link costs which is very close to the lowest link costs. So, the proposed algorithm can get the cost-effective multicast routing for the optical networks.
SERVICE-ORIENTED APPROACH FOR OPTIMAL ROUTING OF INFORMATION FLOWS IN MULTISERVICE NETWORKS
Directory of Open Access Journals (Sweden)
N. I. Listopad
2015-01-01
Full Text Available New approach for optimal routing of information flows is developed based on service-oriented architecture. To find the shortest path it’s require to take into account the QoS-parameters such as delay, jitter, bandwidth, lost of the packets and cost of telecommunication resources.
Directory of Open Access Journals (Sweden)
Nguyen Thanh Long
2015-02-01
Full Text Available MANET (short for Mobile Ad-Hoc Network consists of a set of mobile network nodes, network configuration changes very fast. In content based routing, data is transferred from source node to request nodes is not based on destination addresses. Therefore, it is very flexible and reliable, because source node does not need to know destination nodes. If We can find multiple paths that satisfies bandwidth requirement, split the original message into multiple smaller messages to transmit concurrently on these paths. On destination nodes, combine separated messages into the original message. Hence it can utilize better network resources, causes data transfer rate to be higher, load balancing, failover. Service Oriented Routing is inherited from the model of content based routing (CBR, combined with several advanced techniques such as Multicast, multiple path routing, Genetic algorithm to increase the data rate, and data encryption to ensure information security. Fuzzy logic is a logical field study evaluating the accuracy of the results based on the approximation of the components involved, make decisions based on many factors relative accuracy based on experimental or mathematical proof. This article presents some techniques to support multiple path routing from one network node to a set of nodes with guaranteed quality of service. By using these techniques can decrease the network load, congestion, use network resources efficiently.
Zhang, Lin; Yin, Na; Fu, Xiong; Lin, Qiaomin; Wang, Ruchuan
2017-03-08
With the development of wireless sensor networks, certain network problems have become more prominent, such as limited node resources, low data transmission security, and short network life cycles. To solve these problems effectively, it is important to design an efficient and trusted secure routing algorithm for wireless sensor networks. Traditional ant-colony optimization algorithms exhibit only local convergence, without considering the residual energy of the nodes and many other problems. This paper introduces a multi-attribute pheromone ant secure routing algorithm based on reputation value (MPASR). This algorithm can reduce the energy consumption of a network and improve the reliability of the nodes' reputations by filtering nodes with higher coincidence rates and improving the method used to update the nodes' communication behaviors. At the same time, the node reputation value, the residual node energy and the transmission delay are combined to formulate a synthetic pheromone that is used in the formula for calculating the random proportion rule in traditional ant-colony optimization to select the optimal data transmission path. Simulation results show that the improved algorithm can increase both the security of data transmission and the quality of routing service.
Directory of Open Access Journals (Sweden)
Lin Zhang
2017-03-01
Full Text Available With the development of wireless sensor networks, certain network problems have become more prominent, such as limited node resources, low data transmission security, and short network life cycles. To solve these problems effectively, it is important to design an efficient and trusted secure routing algorithm for wireless sensor networks. Traditional ant-colony optimization algorithms exhibit only local convergence, without considering the residual energy of the nodes and many other problems. This paper introduces a multi-attribute pheromone ant secure routing algorithm based on reputation value (MPASR. This algorithm can reduce the energy consumption of a network and improve the reliability of the nodes’ reputations by filtering nodes with higher coincidence rates and improving the method used to update the nodes’ communication behaviors. At the same time, the node reputation value, the residual node energy and the transmission delay are combined to formulate a synthetic pheromone that is used in the formula for calculating the random proportion rule in traditional ant-colony optimization to select the optimal data transmission path. Simulation results show that the improved algorithm can increase both the security of data transmission and the quality of routing service.
Zhang, Lin; Yin, Na; Fu, Xiong; Lin, Qiaomin; Wang, Ruchuan
2017-01-01
With the development of wireless sensor networks, certain network problems have become more prominent, such as limited node resources, low data transmission security, and short network life cycles. To solve these problems effectively, it is important to design an efficient and trusted secure routing algorithm for wireless sensor networks. Traditional ant-colony optimization algorithms exhibit only local convergence, without considering the residual energy of the nodes and many other problems. This paper introduces a multi-attribute pheromone ant secure routing algorithm based on reputation value (MPASR). This algorithm can reduce the energy consumption of a network and improve the reliability of the nodes’ reputations by filtering nodes with higher coincidence rates and improving the method used to update the nodes’ communication behaviors. At the same time, the node reputation value, the residual node energy and the transmission delay are combined to formulate a synthetic pheromone that is used in the formula for calculating the random proportion rule in traditional ant-colony optimization to select the optimal data transmission path. Simulation results show that the improved algorithm can increase both the security of data transmission and the quality of routing service. PMID:28282894
A Routing Algorithm in WDM Mesh Networks with Grooming Capacities
Institute of Scientific and Technical Information of China (English)
WANG Qiang-min; RONG Meng-tian; ZHU Hong-wen
2005-01-01
Most of the work in traffic grooming has been in the area of providing efficient network designs in Wavelength division multiplexing (WDM). The objective of these traffic grooming algorithms is to reduce the cost of overall networks.In this paper, a routing algorithm based on transiently chaotic neural network is proposed to solve the problem in WDM logical topology. The objectives of the routing algorithm are accommodating all traffic requirements and using less network resource. The simulation shows that the proposed algorithm is efficient in the routing selection, meanwhile the algorithm can use less network resource.
Institute of Scientific and Technical Information of China (English)
SUN Quan; WANG Gong-pu
2006-01-01
The A*Prune quality of service (QoS) routing algorithm was proposed to compute K-shortest paths satisfying multiple QoS constraints. The A*Prune is considered to be one of the practical routing algorithms for intelligent optical networks because of its flexibility in handling many practical constraints. This article gives detailed performance studies of the algorithm through extensive simulation experiments. We found that both the running time and the memory space requirements of the algorithm are large, especially when the network size increases. In this article, we also propose an approach to improving the performance of the A*Prune algorithm. The improvements should make the A*Prune algorithm more attractive for practical use in intelligent optical networks.
Application of Genetic Algorithm on Quality Graded Networks for Intelligent Routing
Nair, T R Gopalakrishnan; 10.1109/WICT.2011.6141306
2012-01-01
In the past decade, significant research has been carried out for realizing intelligent network routing using advertisement, position and near-optimum node selection schemes. In this paper, a grade-based two-level node selection method along with genetic algorithm (GA) is proposed for realizing an efficient routing scheme. This method assumes that the nodes are intelligent and that there exists a knowledge base about the environment in their local memory. There are two levels for approaching the effective route selection process through grading. At the first level, grade-based selection is applied and at the second level, the optimum path is explored using GA. The simulation has been carried out on different topological structures, and a significant reduction in time is achieved for determining the optimal path through this method compared to the non-graded networks.
An energy efficient stable election-based routing algorithm for wireless sensor networks.
Wang, Jin; Zhang, Zhongqi; Xia, Feng; Yuan, Weiwei; Lee, Sungyoung
2013-10-24
Sensor nodes usually have limited energy supply and they are impractical to recharge. How to balance traffic load in sensors in order to increase network lifetime is a very challenging research issue. Many clustering algorithms have been proposed recently for wireless sensor networks (WSNs). However, sensor networks with one fixed sink node often suffer from a hot spots problem since nodes near sinks have more traffic burden to forward during a multi-hop transmission process. The use of mobile sinks has been shown to be an effective technique to enhance network performance features such as latency, energy efficiency, network lifetime, etc. In this paper, a modified Stable Election Protocol (SEP), which employs a mobile sink, has been proposed for WSNs with non-uniform node distribution. The decision of selecting cluster heads by the sink is based on the minimization of the associated additional energy and residual energy at each node. Besides, the cluster head selects the shortest path to reach the sink between the direct approach and the indirect approach with the use of the nearest cluster head. Simulation results demonstrate that our algorithm has better performance than traditional routing algorithms, such as LEACH and SEP.
An Energy Efficient Stable Election-Based Routing Algorithm for Wireless Sensor Networks
Directory of Open Access Journals (Sweden)
Weiwei Yuan
2013-10-01
Full Text Available Sensor nodes usually have limited energy supply and they are impractical to recharge. How to balance traffic load in sensors in order to increase network lifetime is a very challenging research issue. Many clustering algorithms have been proposed recently for wireless sensor networks (WSNs. However, sensor networks with one fixed sink node often suffer from a hot spots problem since nodes near sinks have more traffic burden to forward during a multi-hop transmission process. The use of mobile sinks has been shown to be an effective technique to enhance network performance features such as latency, energy efficiency, network lifetime, etc. In this paper, a modified Stable Election Protocol (SEP, which employs a mobile sink, has been proposed for WSNs with non-uniform node distribution. The decision of selecting cluster heads by the sink is based on the minimization of the associated additional energy and residual energy at each node. Besides, the cluster head selects the shortest path to reach the sink between the direct approach and the indirect approach with the use of the nearest cluster head. Simulation results demonstrate that our algorithm has better performance than traditional routing algorithms, such as LEACH and SEP.
Gems of combinatorial optimization and graph algorithms
Skutella, Martin; Stiller, Sebastian; Wagner, Dorothea
2015-01-01
Are you looking for new lectures for your course on algorithms, combinatorial optimization, or algorithmic game theory? Maybe you need a convenient source of relevant, current topics for a graduate student or advanced undergraduate student seminar? Or perhaps you just want an enjoyable look at some beautiful mathematical and algorithmic results, ideas, proofs, concepts, and techniques in discrete mathematics and theoretical computer science? Gems of Combinatorial Optimization and Graph Algorithms is a handpicked collection of up-to-date articles, carefully prepared by a select group of international experts, who have contributed some of their most mathematically or algorithmically elegant ideas. Topics include longest tours and Steiner trees in geometric spaces, cartograms, resource buying games, congestion games, selfish routing, revenue equivalence and shortest paths, scheduling, linear structures in graphs, contraction hierarchies, budgeted matching problems, and motifs in networks. This ...
ROUTING AND WAVELENGTH ASSIGNMENT ALGORITHMS BASED ON EQUIVALENT NETWORKS
Institute of Scientific and Technical Information of China (English)
Qi Xiaogang; Liu Lifang; Lin Sanyang
2006-01-01
In this paper, a Wavelength Division Multiplexing (WDM) network model based on the equivalent networks is described, and wavelength-dependent equivalent arc, equivalent networks, equivalent multicast tree and some other terms are presented. Based on this model and relevant Routing and Wavelength Assignment (RWA) strategy, a unicast RWA algorithm and a multicast RWA algorithm are presented. The wavelength-dependent equivalent arc expresses the schedule of local RWA and the equivalent network expresses the whole topology of WDM optical networks, so the two algorithms are of the flexibility in RWA and the optimization of the whole problem. The theoretic analysis and simulation results show the two algorithms are of the stronger capability and the lower complexity than the other existing algorithms for RWA problem, and the complexity of the two algorithms are only related to the scale of the equivalent networks. Finally, we prove the two algorithms' feasibility and the one-by-one corresponding relation between the equivalent multicast tree and original multicast tree, and point out the superiorities and drawbacks of the two algorithms respectively.
Routing Diverse Evacuees with the Cognitive Packet Network Algorithm
Directory of Open Access Journals (Sweden)
Huibo Bi
2014-04-01
Full Text Available Regarding mobility, health conditions and personal preferences, evacuees can be categorized into different classes in realistic environments. Previous emergency navigation algorithms that direct evacuees with a single decision rule cannot fulfil civilians’ distinct service requirements and increase the likelihood of inducing destructive crowd behaviours, such as clogging, pushing and trampling, due to diverse mobility. This paper explores a distributed emergency navigation algorithm that employs the cognitive packet network concept to tailor different quality of service needs to different categories of evacuees. In addition, a congestion-aware algorithm is presented to predict the future congestion degree of a path with respect to the observed population density, arrival rate and service rate of each route segment. Experiments are implemented in a simulated environment populated with autonomous agents. Results show that our algorithm can increase the number of survivors while providing improved quality of service.
Express company’s vehicle routing optimization by multiple-dynamic saving algorithm
Directory of Open Access Journals (Sweden)
Junchao Liu
2014-05-01
Full Text Available Purpose: According to the disorder in circulation commuting and crossover commuting of SF company which is the China’s largest private express delivery service provider, the study uses the Saving Algorithm to make the vehicle routing and resources optimized, on this basis, proposes innovative improvements with Saving Algorithm and then applies it in every distribution center of SF forming a "multi-dynamic" type of Saving Algorithm to ensure both cost savings and timeliness. This method can be generalized for all express company to get the vehicle routing optimized.Design/methodology/approach: As the special transportation requirements of express companies, this study optimizes the vehicle route based on Saving Algorithm, uses multiple-dynamic Saving Algorithm, and considers the timeliness requirements of the express company to achieve a balance of cost and timeliness.Findings: The main finding is that a new method proposed which there can be a balance improvement for both cost and timeliness to optimize the vehicle route of express company. Calculation example validates the effectiveness of the model established and solving method.Practical implications: It is a widespread practice that by setting up model and parameters for the objectives, express company can maintain the balances between cost and timeliness and achieve the optimized vehicle route.Originality/value: It proposes innovative improvements, takes SF express company as an example, with Saving Algorithm which can be applied in every distribution center of express company to ensure the balance improvement for both cost and timeliness, and has a great practical significance to the transportation network and path optimization of express companies.
LSP Networks - A Mechanism for Loop free and Loss less Convergence and Implementation
Directory of Open Access Journals (Sweden)
V.Sunilkumar
2010-06-01
Full Text Available When using Link-State Protocols such as OSPF or IS-IS used in the networks, As a response to a topological change forwarding loops can occur transiently when the routers adapt their forwarding tables. In this paper, we proposed and simulate a mechanism that lets the network converge to its optimal state with loop free and the related packet lossless. The mechanism is based on an ordering of the updates of the forwarding tables of the routers.. Typically we have chosen a Network consisting of routers. Link costs are generated randomly forsimulation. Dijkstra’s algorithm has been employed for computing shortest paths. Routing tables are computed dynamically. Link failures are simulated. Avoiding transient loops in each case is demonstrated, by constructing a Reverse Shortest Path Tree using Spanning Tree Algorithm of the Graph. Keywords: LSP networks, OSPF (Open Shortest Path First, FIB, Link Failures, Shortest path algorithm, Spanning tree algorithm.
基于遗传算法的Ad hoc路由协议优化%Routing Protocol Optimization for Ad hoc Networks Based on Genetic Algorithm
Institute of Scientific and Technical Information of China (English)
詹思瑜; 李建平
2012-01-01
目前存在大量的Ad hoc网络路由协议,但是很少有研究对这些协议的最优性能进行过分析.通过对Ad hoc网络路由协议的分析,结合遗传算法的基本原理,对路由协议参数的全局优化配置提出一种启发式求解算法.该算法采用可变长编码,结合遗传算法的选择、交叉和变异操作,对路由协议的性能进行全局优化.在NS2平台上的仿真试验结果表明,优化后的路由协议性能比未优化之前提高30％.%A huge number of routing protocols have been proposed but few researches of the optimal performance of these protocols have been done. In this paper, the performance of Ad hoc networks routing protocols was studied and a novel algorithm was proposed to do a global optimization for routing protocols parameters setting based on genetic algorithm. The presented algorithm adopted variable-length chromosomes encoding, applied selection, crossover and mutation to optimize the routing protocols performance of Ad hoc networks. As shown in our simulations implemented on ns2, the performance of optimized routing protocols can be improved more than 30%.
Rahat, Alma A M; Everson, Richard M; Fieldsend, Jonathan E
2015-01-01
Mesh network topologies are becoming increasingly popular in battery-powered wireless sensor networks, primarily because of the extension of network range. However, multihop mesh networks suffer from higher energy costs, and the routing strategy employed directly affects the lifetime of nodes with limited energy resources. Hence when planning routes there are trade-offs to be considered between individual and system-wide battery lifetimes. We present a multiobjective routing optimisation approach using hybrid evolutionary algorithms to approximate the optimal trade-off between the minimum lifetime and the average lifetime of nodes in the network. In order to accomplish this combinatorial optimisation rapidly, our approach prunes the search space using k-shortest path pruning and a graph reduction method that finds candidate routes promoting long minimum lifetimes. When arbitrarily many routes from a node to the base station are permitted, optimal routes may be found as the solution to a well-known linear program. We present an evolutionary algorithm that finds good routes when each node is allowed only a small number of paths to the base station. On a real network deployed in the Victoria & Albert Museum, London, these solutions, using only three paths per node, are able to achieve minimum lifetimes of over 99% of the optimum linear program solution's time to first sensor battery failure.
An Effective Hybrid Optimization Algorithm for Capacitated Vehicle Routing Problem
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
Capacitated vehicle routing problem (CVRP) is an important combinatorial optimization problem. However, it is quite difficult to achieve an optimal solution with the traditional optimization methods owing to the high computational complexity. A hybrid algorithm was developed to solve the problem, in which an artificial immune clonal algorithm (AICA) makes use of the global search ability to search the optimal results and simulated annealing (SA) algorithm employs certain probability to avoid becoming trapped in a local optimum. The results obtained from the computational study show that the proposed algorithm is a feasible and effective method for capacitated vehicle routing problem.
Efficient path routing strategy for flows with multiple priorities on scale-free networks
Zhou, Zhili; Cheng, Dong
2017-01-01
In real networks, traffic flows are different in amount as well as their priorities. However, the latter priority has rarely been examined in routing strategy studies. In this paper, a novel routing algorithm, which is based on the efficient path routing strategy (EP), is proposed to overcome network congestion problem caused by large amount of traffic flows with different priorities. In this scheme, traffic flows with different priorities are transmitted through different routing paths, which are based on EP with different parameters. Simulation results show that the traffic capacity for flows with different priorities can be enhanced by 12% with this method, compared with EP. In addition, the new method contributes to more balanced network traffic load distribution and reduces average transmission jump and delay of packets. PMID:28199382
Optimal Path Planning for Mobile Robot Using Tailored Genetic Algorithm
Directory of Open Access Journals (Sweden)
Dong Xiao Xian
2013-07-01
Full Text Available During routine inspecting, mobile robot may be requested to visit multiple locations to execute special tasks occasionally. This study aims at optimal path planning for multiple goals visiting task based on tailored genetic algorithm. The proposed algorithm will generate an optimal path that has the least idle time, which is proven to be more effective on evaluating a path in our previous work. In proposed algorithm, customized chromosome representing a path and genetic operators including repair and cut are developed and implemented. Afterwards, simulations are carried out to verify the effectiveness and applicability. Finally, analysis of simulation results is conducted and future work is addressed.
NONMONOTONE PRECONDITIONAL CURVILINEAR PATH ALGORITHMS FOR UNCONSTRAINED OPTIMIZATION
Institute of Scientific and Technical Information of China (English)
朱德通
2003-01-01
This paper presents nonmonotonic quasi-Newton algorithms via two pre-conditional curvilinear paths, the preconditional modified gradient path and the precon-ditional optimal path, for unconstrained optimization problem. We employ the stableBunch-Parlett factorization method to form two curvilinear paths very easily. Thenonmonotone criterion is used to speed up the convergence progress in the contoursof objective function with large curvature. Theoretical analyses are given which provethat the proposed algorithms are globally convergent and have a local superlinear con-vergence rate under some reasonable conditions. The results of numerical experimentsare reported to show the effectiveness of the proposed algorithms.
Directory of Open Access Journals (Sweden)
Danuri Danuri
2013-01-01
Abstract The shortest path determination is an optimization problem which often used as a case study for research. Distance is the most defining factor in performing the search paths to be passed. Path with the shortest distance would be chosen as a path selection. Bee colony optimization algorithm used in this study to complete problems shortest path determination. There are two main process es during search path that is forward and backward. Bee colony optimization algorithm works on the process forward. The value probability of a path is base intransition process and the duration of waggle dance track of every bee who had found the position of the goal will be a preferred route. The results obtained in this study is the bee colony optimization algorithm can be used to find shortest path. The number of bees are released greatly affects in finding routes that can be passed. The more the number of bees that removed the greater the chances of finding the shortest path. Keyword— Shortest Path, Bee Colony Optimization Algorithm
Institute of Scientific and Technical Information of China (English)
王谦; 吴启武; 姜灵芝
2014-01-01
针对光网络中的安全路由问题,通过采用 MaxLAR(最大光路攻击半径)准则,运用人工鱼群算法的快速搜索和全局寻优能力,提出了一种新的基于人工鱼群优化的光网络攻击感知路由算法。该算法可找出在给定条件下光路中最小的 Ma x-LAR,可增强光网络的攻击预防能力,减少潜在物理层攻击对光路造成的可能损伤。算法分析及 Benchmark测试函数实验表明,该算法是可行的,且取得了较好的性能。%In respect of the security routing in optical networks,this paper proposes a new attack-aware routing algorithm for optical networks based on artificial fish swarm optimization in compliance with the Maximum Light path Attack Radius (Max-LAR)criterion,using the fast search and global optimization ability of the artificial fish swarm algorithm.This algorithm can find out the smallest maximum attack radius in light paths under given conditions,enhance the attack prevention ability of opti-cal networks and minimize the possible damage to light paths caused by the potential physical-layer attacks.Algorithm analysis and Benchmark test function experiments indicate that this algorithm is feasible and has good performance.
On the Emergence of Shortest Paths by Reinforced Random Walks
Figueiredo, Daniel R
2016-01-01
The co-evolution between network structure and functional performance is a fundamental and challenging problem whose complexity emerges from the intrinsic interdependent nature of structure and function. Within this context, we investigate the interplay between the efficiency of network navigation (i.e., path lengths) and network structure (i.e., edge weights). We propose a simple and tractable model based on iterative biased random walks where edge weights increase over time as function of the traversed path length. Under mild assumptions, we prove that biased random walks will eventually only traverse shortest paths in their journey towards the destination. We further characterize the transient regime proving that the probability to traverse non-shortest paths decays according to a power-law. We also highlight various properties in this dynamic, such as the trade-off between exploration and convergence, and preservation of initial network plasticity. We believe the proposed model and results can be of inter...
OPTIMIZATION OF DISJOINTS FOR MINIMIZATION OF FAILURE IN WDM OPTICAL NETWORK
Directory of Open Access Journals (Sweden)
A. Renugadevi
2015-06-01
Full Text Available In an optical network, the fiber optic cable is used for communication between the nodes in a network by passing lights. The main problem in optical network is finding the link disjoints as well as optimal solution for the disjoints. To tolerate a single link failure in the network, the enhanced active path first algorithm is used which computes the re-routed back-up path. The multiple link failure in a network called fibre span disjoint path problem is solved using integer linear programming algorithm. The loop back recovery is used to provide pre-planned recovery of link or node failures in a network which allows dynamic choice of routes over pre-planned directions. Considering reliability in a mesh networks, the reliability algorithm helps to achieve the maximum reliability in two-path protection. It addresses the multiple disjoint failures that arise in a network and discusses the best solution between paths shared nodes or links. The unified algorithm is used to generate the optimal results with minimum cost for multiple link failures. The heuristic algorithm namely maximum arbitrary double-link protection algorithm helps to pre-compute the back-up path for double-link failures. In all the above approaches the shortest optimized path must be improved. To find the best shortest path, link-disjoint lightpath algorithm is designed to compute the disjoint occurred in a network and it also satisfies the wavelength continuity constraint in wavelength division multiplexing. A polynomial time algorithm Wavelength Division Multiplexing – Passive Optical Networking is used to compute the disjoint happen in the network. The overall time efficiency is analyzed and performance is evaluated through simulations.
Combinatorial optimization networks and matroids
Lawler, Eugene
2011-01-01
Perceptively written text examines optimization problems that can be formulated in terms of networks and algebraic structures called matroids. Chapters cover shortest paths, network flows, bipartite matching, nonbipartite matching, matroids and the greedy algorithm, matroid intersections, and the matroid parity problems. A suitable text or reference for courses in combinatorial computing and concrete computational complexity in departments of computer science and mathematics.
Energy optimal routing for long chain-type wireless sensor networks in underground mines
Institute of Scientific and Technical Information of China (English)
Jiang Haifeng; Qian Jiansheng; Sun Yanjing; Zhang Guoyong
2011-01-01
Wireless sensor networks are useful complements to existing monitoring systems in underground mines.They play an important role of enhancing and improving coverage and flexibility of safety monitoring systems. Regions prone to danger and enyironments after disasters in underground mines require saving and balancing energy consumption of nodes to prolong the lifespan of networks. Based on the structure of a tunnel, we present a Long Chain-type Wireless Sensor Network (LC-WSN) to monitor the safety of underground mine tunnels. We define the optimal transmission distance and the range of the key region and present an Energy Optimal Routing (EOR) algorithm for LC-WSN to balance the energy consumption of nodes and maximize the lifespan of networks. EOR constructs routing paths based on an optimal transmission distance and uses an energy balancing strategy in the key region. Simulation results show that the EOR algorithm extends the lifespan of a network, balances the energy consumption of nodes in the key region and effectively limits the length of routing paths, compared with similar algorithms.
Multiobjective Genetic Algorithm for QoS Routing in Wireless Mesh Networks
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Wilson Soto
2013-11-01
Full Text Available The wireless mesh network is the type of network more used currently, the same as show interesting challenges in the topic of investigation. One of the challenges is as improve the capability of a network to provide better service to selected network traffic over various technologies. This requires keep in mind variables such as delay, jitter, packet loss and band width. This type of challenge where is necessary to optimize several variables becomes a combinatorial and computational complex problem. A method for solve this type of problems are the genetic algorithms. In this work we show a multiobjective genetic algorithm for quality of service in routing in wireless mesh networks. The proposed genetic algorithm besides has the advantage of use the Pareto frontier algorithm with the divide and conquer technique and the knee algorithm for to select an only solution of the problem. The paths found for the proposed algorithm demonstrate that achieve the purpose to improve the quality of service in routing in wireless mesh networks.
An Effective Randomized QoS Routing Algorithm on Networks with Inaccurate Parameters
Institute of Scientific and Technical Information of China (English)
WANG Jianxin(王建新); CHEN Jian'er(陈建二); CHEN Songqiao(陈松乔)
2002-01-01
This paper develops an effective randomized on-demand QoS routing algorithm on networks with inaccurate link-state information. Several new techniques are proposed in the algorithm. First, the maximum safety rate and the minimum delay for each node in the network are pre-computed, which simplify the network complexity and provide the routing process with useful information. The routing process is dynamically directed by the safety rate and delay of the partial routing path developed so far and by the maximum safety rate and the minimum delay of the next node. Randomness is used at the link level and depends dynamically on the routing configuration. This provides great flexibility for the routing process, prevents the routing process from overusing certain fixed routing paths, and adequately balances the safety rate and delay of the routing path. A network testing environment has been established and five parameters are introduced to measure the performance of QoS routing algorithms.Experimental results demonstrate that in terms of the proposed parameters, the algorithm outperforms existing QoS algorithms appearing in the literature.
A Reinforcement Routing Algorithm with Access Selection in the Multi-Hop Multi-Interface Networks
Jafari, Amir Hosein; Shahhoseini, Hadi Shahriar
2015-03-01
In this paper, a routing algorithm is proposed for access selection in a network to find the optimal paths among intermediate nodes with multiple interfaces. Markov Decision Process is applied in each node to find optimal policy and select proper paths to the best access point in a dynamic environment. A reward function is defined as environment feedback to optimize and adapt routing behavior of nodes based on the local information. Selection metrics in each node are interface load, link quality and destination condition. It is shown, by using the proposed algorithm, there are better management in the node which decreases interference and collision and selects links with better quality toward the best possible destination. The performance of the method is exemplified and it is shown how the throughput and average delay of the network with more interface in its nodes, improved while packet loss degrades. As an example a two-interface and a one-interface network are studied. It is shown when network load is increased, interface management will improve the throughput, in the network with two-interface nodes. Also, by considering the link quality factor in the reward function, packet dropping becomes less but average delay increases.
SNMP Based Network Optimization Technique Using Genetic Algorithms
Directory of Open Access Journals (Sweden)
M. Mohamed Surputheen
2012-03-01
Full Text Available Genetic Algorithms (GAs has innumerable applications through the optimization techniques and network optimization is one of them. SNMP (Simple Network Management Protocol is used as the basic network protocol for monitoring the network activities health of the systems. This paper deals with adding Intelligence to the various aspects of SNMP by adding optimization techniques derived out of genetic algorithms, which enhances the performance of SNMP processes like routing.
Directory of Open Access Journals (Sweden)
Yuxin Mao
2013-01-01
Full Text Available The unreliability and dynamics of mobile wireless sensor networks make it hard to perform end-to-end communications. This paper presents a novel source-initiated on-demand routing mechanism for efficient data transmission in mobile wireless sensor networks. It explores the Thorup-Zwick theory to achieve source-initiated on-demand routing with time efficiency. It is able to find out shortest routing path between source and target in a network and transfer data in linear time. The algorithm is easy to be implemented and performed in resource-constrained mobile wireless sensor networks. We also evaluate the approach by analyzing its cost in detail. It can be seen that the approach is efficient to support data transmission in mobile wireless sensor networks.
Mao, Yuxin; Zhu, Ping
2013-01-01
The unreliability and dynamics of mobile wireless sensor networks make it hard to perform end-to-end communications. This paper presents a novel source-initiated on-demand routing mechanism for efficient data transmission in mobile wireless sensor networks. It explores the Thorup-Zwick theory to achieve source-initiated on-demand routing with time efficiency. It is able to find out shortest routing path between source and target in a network and transfer data in linear time. The algorithm is easy to be implemented and performed in resource-constrained mobile wireless sensor networks. We also evaluate the approach by analyzing its cost in detail. It can be seen that the approach is efficient to support data transmission in mobile wireless sensor networks.
Inverse minimum spanning tree problem and reverse shortest-path problem with discrete values
Institute of Scientific and Technical Information of China (English)
LIU Longcheng; HE Yong
2006-01-01
In this paper, we consider two network improvement problems with given discrete values: the inverse minimum spanning tree problem and the reverse shortest-path problem, where the decrements of the weight of the edges are given discrete values. First,for the three models of the inverse minimum spanning tree problem (the sum-type, the bottleneck-type and the constrained bottlenecktype), we present their respective strongly polynomial algorithms. Then, we show that the reverse shortest-path problem is strongly NP-complete.
Adaptive Bio-Inspired Wireless Network Routing for Planetary Surface Exploration
Alena, Richard I.; Lee, Charles
2004-01-01
Wireless mobile networks suffer connectivity loss when used in a terrain that has hills, and valleys when line of sight is interrupted or range is exceeded. To resolve this problem and achieve acceptable network performance, we have designed an adaptive, configurable, hybrid system to automatically route network packets along the best path between multiple geographically dispersed modules. This is very useful in planetary surface exploration, especially for ad-hoc mobile networks, where computational devices take an active part in creating a network infrastructure, and can actually be used to route data dynamically and even store data for later transmission between networks. Using inspiration from biological systems, this research proposes to use ant trail algorithms with multi-layered information maps (topographic maps, RF coverage maps) to determine the best route through ad-hoc network at real time. The determination of best route is a complex one, and requires research into the appropriate metrics, best method to identify the best path, optimizing traffic capacity, network performance, reliability, processing capabilities and cost. Real ants are capable of finding the shortest path from their nest to a food source without visual sensing through the use of pheromones. They are also able to adapt to changes in the environment using subtle clues. To use ant trail algorithms, we need to define the probability function. The artificial ant is, in this case, a software agent that moves from node to node on a network graph. The function to calculate the fitness (evaluate the better path) includes: length of the network edge, the coverage index, topology graph index, and pheromone trail left behind by other ant agents. Each agent modifies the environment in two different ways: 1) Local trail updating: As the ant moves between nodes it updates the amount of pheromone on the edge; and 2) Global trail updating: When all ants have completed a tour the ant that found the
Study on an urban transportation optimal path algorithm%城市交通最优路径算法
Institute of Scientific and Technical Information of China (English)
陈亮; 何为; 韩力群
2012-01-01
城市智能交通系统中,最优路径算法及其优化是研究热点之一,是整个交通系统较为核心的部分.结合图论中最短路径算法,研究了城市交通可达路径算法,并对其进行了有效优化,通过图论中的路径代价函数,提出了城市最优路径算法,在此基础上,通过优化搜索区域、可达路径的搜索方向以及路网分层搜索等优化策略,达到了优化城市最优路径算法的目的,提出的城市最优路径及其优化算法能够给出行者提供多条参考的时间最优路线,方便出行者选择.通过算法的应用实例,验证了城市最优路径及其优化算法的有效性与实时性.%In urban intelligent transportation systems, the optimal path algorithm and its optimization are hot topic and the core of the whole transportation system. By introducing the shortest path algorithm in graph theory, this paper first researched the accessible paths for the urban transportation along with an optimization algorithm. Next, by using the path cost function, an optimal path algorithm for urban transportation was proposed. On this basis, by optimizing the search area, the search direction for accessible paths, and the road network hierarchical search optimization strategy, the goal of optimizing urban paths was attained. The proposed optimal urban path and its optimization algorithm were able to provide several time-optimal pedestrian paths for references. Through practical applications, the validity and real-time characteristics of the proposed urban optimal path and its optimization algorithm were verified.
Effective caching of shortest paths for location-based services
DEFF Research Database (Denmark)
Jensen, Christian S.; Thomsen, Jeppe Rishede; Yiu, Man Lung
2012-01-01
Web search is ubiquitous in our daily lives. Caching has been extensively used to reduce the computation time of the search engine and reduce the network traffic beyond a proxy server. Another form of web search, known as online shortest path search, is popular due to advances in geo...
Simple and accurate analytical calculation of shortest path lengths
Melnik, Sergey
2016-01-01
We present an analytical approach to calculating the distribution of shortest paths lengths (also called intervertex distances, or geodesic paths) between nodes in unweighted undirected networks. We obtain very accurate results for synthetic random networks with specified degree distribution (the so-called configuration model networks). Our method allows us to accurately predict the distribution of shortest path lengths on real-world networks using their degree distribution, or joint degree-degree distribution. Compared to some other methods, our approach is simpler and yields more accurate results. In order to obtain the analytical results, we use the analogy between an infection reaching a node in $n$ discrete time steps (i.e., as in the susceptible-infected epidemic model) and that node being at a distance $n$ from the source of the infection.
Research on network failure handling technology based on deflection routing
Institute of Scientific and Technical Information of China (English)
Tao YU; Shanzhi CHEN; Xin LI; Zhen QIN
2008-01-01
A new deflection routing scheme is proposed to overcome the drawback of existing deflection routing scheme that cannot handle node failure and suffer from routing loops.A new algorithm for computing the backup shortest path tree(SPT)is proposed and a set of procedures are defined for utilizing the backup SPT in case of node or link failure.The failure can be handled swiftly and the backup routes are guaranteed to be loop-free.Experimental results show that the backup routes calculated by proposed scheme are close to the optimal routes by totally re-computing.
Decision Support for Route Search and Optimum Finding in Transport Networks under Uncertainty
Directory of Open Access Journals (Sweden)
G. Szücs
2015-02-01
Full Text Available The aim of this paper is to find solution for route planning in road network for a user, and to find the equilibrium in the path optimization problem, where the roads have uncertain attributes. The concept is based on the Dempster-Shafer theory and Dijkstra's algorithm, which help to model the uncertainty and to find the best route, respectively. Based on uncertain influencing factors an interval of travel time (so called cost interval of each road can be calculated. An algorithm has been outlined for determining the best route comparing the intervals and using decision rules depending on the user's attitude. Priorities can be defined among the rules, and the constructed rule based mechanism for users’ demands is great contribution of this paper. The first task is discussed in more general in this paper, i.e. instead of travel time a general cost is investigated for any kind of network. At the solution of the second task, where the goal is to find equilibrium in transport network at case of uncertain situation, the result of the first task is used. Simulation tool has been used to find the equilibrium, which gives only approximate solution, but this is sufficient and appropriate solution for large networks. Furthermore this is built in a decision support system, which is another contribution of this work. At the end of the paper the implementation of the theoretical concept is presented with a test bed of a town presenting effects of different uncertain influencing factors for the roads.
Wang, Fu; Liu, Bo; Zhang, Lijia; Xin, Xiangjun; Tian, Qinghua; Zhang, Qi; Rao, Lan; Tian, Feng; Luo, Biao; Liu, Yingjun; Tang, Bao
2016-10-01
Elastic Optical Networks are considered to be a promising technology for future high-speed network. In this paper, we propose a RSA algorithm based on the ant colony optimization of minimum consecutiveness loss (ACO-MCL). Based on the effect of the spectrum consecutiveness loss on the pheromone in the ant colony optimization, the path and spectrum of the minimal impact on the network are selected for the service request. When an ant arrives at the destination node from the source node along a path, we assume that this path is selected for the request. We calculate the consecutiveness loss of candidate-neighbor link pairs along this path after the routing and spectrum assignment. Then, the networks update the pheromone according to the value of the consecutiveness loss. We save the path with the smallest value. After multiple iterations of the ant colony optimization, the final selection of the path is assigned for the request. The algorithms are simulated in different networks. The results show that ACO-MCL algorithm performs better in blocking probability and spectrum efficiency than other algorithms. Moreover, the ACO-MCL algorithm can effectively decrease spectrum fragmentation and enhance available spectrum consecutiveness. Compared with other algorithms, the ACO-MCL algorithm can reduce the blocking rate by at least 5.9% in heavy load.
Routing Optimization Based on Taboo Search Algorithm for Logistic Distribution
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Hongxue Yang
2014-04-01
Full Text Available Along with the widespread application of the electronic commerce in the modern business, the logistic distribution has become increasingly important. More and more enterprises recognize that the logistic distribution plays an important role in the process of production and sales. A good routing for logistic distribution can cut down transport cost and improve efficiency. In order to cut down transport cost and improve efficiency, a routing optimization based on taboo search for logistic distribution is proposed in this paper. Taboo search is a metaheuristic search method to perform local search used for logistic optimization. The taboo search is employed to accelerate convergence and the aspiration criterion is combined with the heuristics algorithm to solve routing optimization. Simulation experimental results demonstrate that the optimal routing in the logistic distribution can be quickly obtained by the taboo search algorithm
Multi-constraint quality of service routing algorithm for dynamic topology networks
Institute of Scientific and Technical Information of China (English)
无
2008-01-01
An adaptive multi-QoS routing algorithm called AMQRA is proposed for dynamic topology networks,such as satellite networks and Ad-hoc networks.The AMQRA is a distributed and mobile-agents-based routing algorithm,which combines ant quantity system (AQS) with ant colony optimization (ACO) that is used in AntNet routing algorithm.In dynamic topology networks,the AMQRA achieves timely optimization for concave metric QoS constraint and fast convergence.The proposed routing algorithm is simulated in Iridium satellite constellation on OPNET.The results show that AMQRA not only outperforms the AntNet in convergence rate in dynamic topology networks but also can optimize concave metric QoS constraint and reasonably allot bandwidth to the load to avoid networks congestion.
Optimal Routing with Failure-Independent Path Protection
DEFF Research Database (Denmark)
Stidsen, Thomas Riis; Petersen, Bjørn; Spoorendonk, Simon
2010-01-01
the associated routing problems become much harder. In this article we present a rigorous mathematical analysis of one of the most promising protection methods: Failure independent path protection. We present an LP model which is solved by column generation. The subproblem is proven to be strongly P...
An energy efficient clustering routing algorithm for wireless sensor networks
Institute of Scientific and Technical Information of China (English)
LI Li; DONG Shu-song; WEN Xiang-ming
2006-01-01
This article proposes an energy efficient clustering routing (EECR) algorithm for wireless sensor network. The algorithm can divide a sensor network into a few clusters and select a cluster head base on weight value that leads to more uniform energy dissipation evenly among all sensor nodes.Simulations and results show that the algorithm can save overall energy consumption and extend the lifetime of the wireless sensor network.
Zheng, Feifei; Simpson, Angus R.; Zecchin, Aaron C.
2011-08-01
This paper proposes a novel optimization approach for the least cost design of looped water distribution systems (WDSs). Three distinct steps are involved in the proposed optimization approach. In the first step, the shortest-distance tree within the looped network is identified using the Dijkstra graph theory algorithm, for which an extension is proposed to find the shortest-distance tree for multisource WDSs. In the second step, a nonlinear programming (NLP) solver is employed to optimize the pipe diameters for the shortest-distance tree (chords of the shortest-distance tree are allocated the minimum allowable pipe sizes). Finally, in the third step, the original looped water network is optimized using a differential evolution (DE) algorithm seeded with diameters in the proximity of the continuous pipe sizes obtained in step two. As such, the proposed optimization approach combines the traditional deterministic optimization technique of NLP with the emerging evolutionary algorithm DE via the proposed network decomposition. The proposed methodology has been tested on four looped WDSs with the number of decision variables ranging from 21 to 454. Results obtained show the proposed approach is able to find optimal solutions with significantly less computational effort than other optimization techniques.
An Efficient Routing Algorithm in Ad Hoc Networks
Institute of Scientific and Technical Information of China (English)
WANGShuqiao; LIHongyan; LIJiandong
2005-01-01
The Dynamic source routing protocol(DSR) is an on-demand routing protocol, designed specifically for use in multi-hop wireless ad hoc networks of mobile nodes. In this paper, some mechanisms such as the route's lifetime prediction, route’s creation time and an adaptive gratuitous route reply mode are introduced into DSR to get an efficient routing algorithm which is refered to E-DSR. The simulation results show that E-DSR can improve the packet delivery rate and reduce the routing overhead compared with hop-based DSR.
An Improved Ant Colony Routing Algorithm for WSNs
Directory of Open Access Journals (Sweden)
Tan Zhi
2015-01-01
Full Text Available Ant colony algorithm is a classical routing algorithm. And it are used in a variety of application because it is economic and self-organized. However, the routing algorithm will expend huge amounts of energy at the beginning. In the paper, based on the idea of Dijkstra algorithm, the improved ant colony algorithm was proposed to balance the energy consumption of networks. Through simulation and comparison with basic ant colony algorithms, it is obvious that improved algorithm can effectively balance energy consumption and extend the lifetime of WSNs.
Directory of Open Access Journals (Sweden)
Jiang Ting
2010-01-01
Full Text Available We optimize the cluster structure to solve problems such as the uneven energy consumption of the radar sensor nodes and random cluster head selection in the traditional clustering routing algorithm. According to the defined cost function for clusters, we present the clustering algorithm which is based on radio-free space path loss. In addition, we propose the energy and distance pheromones based on the residual energy and aggregation of the radar sensor nodes. According to bionic heuristic algorithm, a new ant colony-based clustering algorithm for radar sensor networks is also proposed. Simulation results show that this algorithm can get a better balance of the energy consumption and then remarkably prolong the lifetime of the radar sensor network.
Directory of Open Access Journals (Sweden)
Jin Yang
2016-07-01
Full Text Available Mobile sinks can achieve load-balancing and energy-consumption balancing across the wireless sensor networks (WSNs. However, the frequent change of the paths between source nodes and the sinks caused by sink mobility introduces significant overhead in terms of energy and packet delays. To enhance network performance of WSNs with mobile sinks (MWSNs, we present an efficient routing strategy, which is formulated as an optimization problem and employs the particle swarm optimization algorithm (PSO to build the optimal routing paths. However, the conventional PSO is insufficient to solve discrete routing optimization problems. Therefore, a novel greedy discrete particle swarm optimization with memory (GMDPSO is put forward to address this problem. In the GMDPSO, particle’s position and velocity of traditional PSO are redefined under discrete MWSNs scenario. Particle updating rule is also reconsidered based on the subnetwork topology of MWSNs. Besides, by improving the greedy forwarding routing, a greedy search strategy is designed to drive particles to find a better position quickly. Furthermore, searching history is memorized to accelerate convergence. Simulation results demonstrate that our new protocol significantly improves the robustness and adapts to rapid topological changes with multiple mobile sinks, while efficiently reducing the communication overhead and the energy consumption.
Yang, Jin; Liu, Fagui; Cao, Jianneng; Wang, Liangming
2016-07-14
Mobile sinks can achieve load-balancing and energy-consumption balancing across the wireless sensor networks (WSNs). However, the frequent change of the paths between source nodes and the sinks caused by sink mobility introduces significant overhead in terms of energy and packet delays. To enhance network performance of WSNs with mobile sinks (MWSNs), we present an efficient routing strategy, which is formulated as an optimization problem and employs the particle swarm optimization algorithm (PSO) to build the optimal routing paths. However, the conventional PSO is insufficient to solve discrete routing optimization problems. Therefore, a novel greedy discrete particle swarm optimization with memory (GMDPSO) is put forward to address this problem. In the GMDPSO, particle's position and velocity of traditional PSO are redefined under discrete MWSNs scenario. Particle updating rule is also reconsidered based on the subnetwork topology of MWSNs. Besides, by improving the greedy forwarding routing, a greedy search strategy is designed to drive particles to find a better position quickly. Furthermore, searching history is memorized to accelerate convergence. Simulation results demonstrate that our new protocol significantly improves the robustness and adapts to rapid topological changes with multiple mobile sinks, while efficiently reducing the communication overhead and the energy consumption.
Topological Routing in Large-Scale Networks
DEFF Research Database (Denmark)
Pedersen, Jens Myrup; Knudsen, Thomas Phillip; Madsen, Ole Brun
2004-01-01
A new routing scheme, Topological Routing, for large-scale networks is proposed. It allows for efficient routing without large routing tables as known from traditional routing schemes. It presupposes a certain level of order in the networks, known from Structural QoS. The main issues in applying...... Topological Routing to large-scale networks are discussed. Hierarchical extensions are presented along with schemes for shortest path routing, fault handling and path restoration. Further reserach in the area is discussed and perspectives on the prerequisites for practical deployment of Topological Routing...
Topological Routing in Large-Scale Networks
DEFF Research Database (Denmark)
Pedersen, Jens Myrup; Knudsen, Thomas Phillip; Madsen, Ole Brun
A new routing scheme, Topological Routing, for large-scale networks is proposed. It allows for efficient routing without large routing tables as known from traditional routing schemes. It presupposes a certain level of order in the networks, known from Structural QoS. The main issues in applying...... Topological Routing to large-scale networks are discussed. Hierarchical extensions are presented along with schemes for shortest path routing, fault handling and path restoration. Further reserach in the area is discussed and perspectives on the prerequisites for practical deployment of Topological Routing...
Optimal Routing in a Small-World Network
Institute of Scientific and Technical Information of China (English)
Jian-Yang Zeng; Wen-Jing Hsu
2006-01-01
Substantial research has been devoted to the modelling of the small-world phenomenon that arises in nature as well as human society. Earlier work has focused on the static properties of various small-world models. To examine the routing aspects, Kleinberg proposes a model based on a d-dimensional toroidal lattice with long-range links chosen at random according to the d-harmonic distribution. Kleinberg shows that, by using only local information, the greedy routing algorithm performs in O(lg2 n) expected number of hops. We extend Kleinberg's small-world model by allowing each node x to have two more random links to nodes chosen uniformly and randomly within (lg n)-d Manhattan distance from x. Basedon this extended model, we then propose an oblivious algorithm that can route messages between any two nodes in O(lg n)expected number of hops. Our routing algorithm keeps only O((lg n)β+1) bits of information on each node, where 1 ＜β＜ 2,thus being scalable w.r.t. the network size. To our knowledge, our result is the first to achieve the optimal routing complexity while still keeping a poly-logarithmic number of bits of information stored on each node in the small-world networks.
Ants-Based On-Demand Routing Algorithm for Mobile Ad Hoc Networks
Institute of Scientific and Technical Information of China (English)
无
2005-01-01
An ants-based on-demand routing algorithm (AORA) specialized for mobile ad hoc networks is proposed. AORA measures the network's traffic information including delivery time,route energy etc. by the continuous delivery of data packets,then calculates the compositive parameter for each route which can be seen as the stigmity and uses it to choose the comparatively optimal route in real time.To adjust the weight of each traffic information,the algorithm can meet the different demand of the network's user. Multipath source self repair routing (MSSRR) algorithm and dynamic source routing (DSR) can be seen as the special samples of AORA. The routing overhead is not increased in this algorithm. By using simulation, it can be seen that the performance of AORA is better than that of DSR in all scenarios obviously,especially the delivery fraction is increased by more than 100%.
An adaptive routing algorithm for flooding performance improving in GMPLS based WDM networks
Ren, Jia; Han, Dahai; Wang, Lei; Gao, Guanjun; Zhang, Jie; Gu, Wanyi; Ji, Yuefeng
2009-11-01
In WDM networks, when a session request is received by the network, the problem of establishing light-paths by routing and assigning a wavelength to this connection session is called the Routing and Wavelength Assignment (RWA) problem. The selection of routing algorithm and wavelength assignment method is the key point to solve this problem. And the flooding technique is always used for those routing algorithms to get the resource status and topology information. In this paper, we propose a novel routing algorithm, Rank Total wavelengths and Available wavelengths (RTAW), which dramatically reduces the flooding frequency while guaranteeing a low blocking rate. Compared with other algorithms, the simulations results prove the benefits of this algorithm.
Calculating Least Risk Paths in 3d Indoor Space
Vanclooster, A.; De Maeyer, Ph.; Fack, V.; Van de Weghe, N.
2013-08-01
Over the last couple of years, research on indoor environments has gained a fresh impetus; more specifically applications that support navigation and wayfinding have become one of the booming industries. Indoor navigation research currently covers the technological aspect of indoor positioning and the modelling of indoor space. The algorithmic development to support navigation has so far been left mostly untouched, as most applications mainly rely on adapting Dijkstra's shortest path algorithm to an indoor network. However, alternative algorithms for outdoor navigation have been proposed adding a more cognitive notion to the calculated paths and as such adhering to the natural wayfinding behaviour (e.g. simplest paths, least risk paths). These algorithms are currently restricted to outdoor applications. The need for indoor cognitive algorithms is highlighted by a more challenged navigation and orientation due to the specific indoor structure (e.g. fragmentation, less visibility, confined areas…). As such, the clarity and easiness of route instructions is of paramount importance when distributing indoor routes. A shortest or fastest path indoors not necessarily aligns with the cognitive mapping of the building. Therefore, the aim of this research is to extend those richer cognitive algorithms to three-dimensional indoor environments. More specifically for this paper, we will focus on the application of the least risk path algorithm of Grum (2005) to an indoor space. The algorithm as proposed by Grum (2005) is duplicated and tested in a complex multi-storey building. The results of several least risk path calculations are compared to the shortest paths in indoor environments in terms of total length, improvement in route description complexity and number of turns. Several scenarios are tested in this comparison: paths covering a single floor, paths crossing several building wings and/or floors. Adjustments to the algorithm are proposed to be more aligned to the
Congestion Aware Multipath Routing: Aggregation Network Applicability and IPv6 Implementation
Directory of Open Access Journals (Sweden)
Matej Kultan
2015-10-01
Full Text Available —Currently, the service provider network capacity utilization is low due to the shortest multipath based routing protocols Opens Shortest Path First (OSPF and Intermediate System-to-Intermediate System (ISIS. Due to inefficient routing approach, certain paths can be overloaded and link capacity is required while alternative paths are unused. The overall network has to be dimensioned with higher link bandwidth requirements introducing additional line, linecard, routing engine and overall solution cos. This paper provides improved Congestion Aware Multipath Routing (CAMRv2 algorithm overview. The new network routing algorithm allows higher throughput, network load-balancing and stability to ensure lower congestion and data drop on critical links. The algorithm discovers unused network resources and dynamically adapts to the actual traffic load and displacement. The focus in this paper is on new parameters for path computation performance improvement. Additionally, detailed IPv6 source routing CAMRv2 implementation for parallel coexistence with present networks is presented. Finally, the new routing algorithm is simulated in several scenarios over aggregation network. The result of simulations have proved better performance and resource utilization of the proposed algorithm in sparse aggregation network in terms of load-balancing between uplinks to the core network
Theory, Design, and Algorithms for Optimal Control of wireless Networks
2010-06-09
significantly outperform existing protocols (such as AODV ) in terms of total network cost Furthermore, we have shown that even when components of our...achieved through distributed control algorithms that jointly optimize power control, routing , and congestion factors. A second stochastic model approach...updates the network queue state, node-transmission powers amongst others, allowing for power control, scheduling, and routing algorithms to maximize
Ant Colony Optimization for Route Allocation in Transportation Networks
Zamfirescu, Constantin-Bǎlǎ; Negulescu, Sorin; Oprean, Constantin; Banciu, Dorin
2009-04-01
The paper introduces a bio-inspired approach to solve the route allocation problem (RAP) in the transportation networks. The approach extends a well-known meta-heuristics algorithm with the real life constraints that are dealt with in the scheduling process (i.e. the uniform distribution of routes diversity for vehicles, the average distance travelled in a month, the driver's rest between subsequent trips etc.). The paper is focusing on the engineering aspects of employing bio-inspired algorithms (which proved to have near-optimal results for toy-like problems) to a real-life application domain. The approach proved to be capable of preserving the software components (agents) to the complexity and dynamics of the situation when the RAP requires incremental extensions of constraints to reflect the traffic conditions in the transportation network.
A CROSS-LAYERED PATH STABILITY BASED ROUTING PROTOCOL FOR WiMAX NETWORKS
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M. Deva Priya
2013-01-01
Full Text Available In IEEE 802.16, a Subscriber Station (SS is battery powered with limited capacity. A SS can be made to operate for longer durations by deploying power saving features or by using relay stations. Multi-hop communication conserves power, but finding an optimal path to the destination is monotonous. Path stability indicates how stable a path is and how long it can support communication. Identifying stable paths helps in reducing the control traffic, number of connection disruptions and also in conserving power. In this study, Greedy Perimeter Stateless Routing (GPSR and Link-St Ability and Energy aware Routing (LAER designed for Mobile Ad hoc NET works (MANETs are implemented for WiMAX networks and their performance is evaluated. Further, a novel Cross-layered Path Stability based Routing protocol (CPSR is proposed to find a stable path based on Residual Energy (RE, Received Signal Strength Indicator (RSSI and Signal-to-Noise Ratio (SNR. The total energy consumed is minimized, thus maximizing the network lifetime.
Optimization of Multiple Vehicle Routing Problems Using Approximation Algorithms
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R. Nallusamy
2009-12-01
Full Text Available This paper deals with generating of an optimized route for multiple Vehicle routing Problems (mVRP. We used a methodology of clustering the given cities depending upon the number of vehicles and eachcluster is allotted to a vehicle. k- Means clustering algorithm has been used for easy clustering of the cities. In this way the mVRP has been converted into VRP which is simple in computation compared to mVRP. After clustering, an optimized route is generated for each vehicle in its allotted cluster. Once the clustering had been done and after the cities were allocated to the various vehicles, each cluster/tour was taken as an individual Vehicle Routing problem and the steps of Genetic Algorithm were applied to the cluster and iterated to obtain the most optimal value of the distance after convergence takes place. After the application of the variousheuristic techniques, it was found that the Genetic algorithm gave a better result and a more optimal tour for mVRPs in short computational time than other Algorithms due to the extensive search and constructive nature of the algorithm.
Dynamic Routing Algorithm for Increasing Robustness in Satellite Networks
Institute of Scientific and Technical Information of China (English)
LI Dong-ni; ZHANG Da-kun
2008-01-01
In low earth orbit(LEO)and medium earth orbit(MEO)satellite networks,the network topology changes rapidly because of the high relative speed movement of satellites.When some inter-satellite links (ISLs)fail,they can not be repaired in a short time.In order to increase the robustness for LEO/MEO satellite networks,an effective dynamic routing algorithm is proposed.All the routes to a certain node are found by constructing a destination oriented acyclic directed graph(DOADG)with the node as the destination.In this algorithm,multiple routes are provided,loop-free is guaranteed,and as long as the DOADG maintains,it is not necessary to reroute even if some ISLs fail.Simulation results show that comparing to the conventional routing algorithms,it is more efficient and reliable,costs less transmission overhead and converges faster.
Directory of Open Access Journals (Sweden)
Juan Carlos Montoya M.
2008-06-01
Full Text Available Multicast juega un papel muy importante para soportar una nueva generación de aplicaciones. En la actualidad y por diferentes razones, técnicas y no técnicas, multicast IP no ha sido totalmente adoptado en Internet. Durante los últimos a˜nos, un área de investigación activa es la de implementar este tipo de tráfico desde la perspectiva del nivel de aplicación, donde la funcionalidad de multicast no es responsabilidad de los enrutadores sino de los hosts, a lo que se le conoce como Multicast Overlay Network (MON. En este artículo se plantea el enrutamiento en MON como un problema de Optimización Multiobjetivo (MOP donde se optimizan dos funciones: 1 el retardo total extremo a extremo del árbol multicast, y 2 la máxima utilización de los enlaces. La optimización simultánea de estas dos funciones es un problema NP completo y para resolverlo se propone utilizar Algoritmos Evolutivos Multiobjetivos (MOEA, específicamente NSGAIMulticast plays an important role in supporting a new generation of applications. At present and for different reasons, technical and non–technical, multicast IP hasn’t yet been totally adopted for Internet. During recent years, an active area of research is that of implementing this kind of traffic in the application layer where the multicast functionality isn´t a responsibility of the routers but that of the hosts, which we know as Multicast Overlay Networks (MON. In this article, routing in an MON is put forward as a multiobjective optimization problem (MOP where two functions are optimized: 1 the total end to end delay of the multicast tree and 2 the maximum link utilization. The simultaneous optimization of these two functions is an NP–Complete problem and to solve this we suggest using Multiobjective Evolutionary Algorithms (MOEA, specifically NSGA–II.
A New RWA Algorithm Based on Multi-Objective
Institute of Scientific and Technical Information of China (English)
无
2003-01-01
In this article, we studied the associated research problems and challenges on routing and wavelength assignment (RWA) in WDM (wavelength division multiplexing) networks. Various RWA approaches are examined and compared. We proposed a new RWA algorithm based on multi-objective. In this new algorithm, we consider multiple network optimizing objectives to setup a lightpath with maximize profit and shortest path under the limited resources. By comparing and analyzing, the proposed algorithm is much better ...
Social-Stratification Probabilistic Routing Algorithm in Delay-Tolerant Network
Alnajjar, Fuad; Saadawi, Tarek
Routing in mobile ad hoc networks (MANET) is complicated due to the fact that the network graph is episodically connected. In MANET, topology is changing rapidly because of weather, terrain and jamming. A key challenge is to create a mechanism that can provide good delivery performance and low end-to-end delay in an intermittent network graph where nodes may move freely. Delay-Tolerant Networking (DTN) architecture is designed to provide communication in intermittently connected networks, by moving messages towards destination via ”store, carry and forward” technique that supports multi-routing algorithms to acquire best path towards destination. In this paper, we propose the use of probabilistic routing in DTN architecture using the concept of social-stratification network. We use the Opportunistic Network Environment (ONE) simulator as a simulation tool to compare the proposed Social- stratification Probabilistic Routing Algorithm (SPRA) with the common DTN-based protocols. Our results show that SPRA outperforms the other protocols.
Optimal Path Selection for Mobile Robot Navigation Using Genetic Algorithm
Directory of Open Access Journals (Sweden)
D Tamilselvi
2011-07-01
Full Text Available The proposed Navigation Strategy using GA(Genetic Algorithm finds an optimal path in the simulated grid environment. GA forces to find a path that is connected to the robot start and target positions via predefined points. Each point in the environmental model is called genome and the path connecting Start and Target is called as Chromosome. According to the problem formulation, the length of the algorithm chromosomes (number of genomes is dynamic. Moreover every genome is not a simple digit. In this case, every genome represents the nodes in the 2D grid environment. After implementing the cross over and mutation concepts the resultant chromosome (path is subjected to optimization process which gives the optimal path as a result. The problem faced with is there may be chances for the loss of the fittest chromosome while performing the reproduction operations. The solution is achieved by inducing the concept of elitism thereby maintaining the population richness. The efficiency of the algorithm is analyzed with respect to execution time and path cost to reach the destination. Path planning, collision avoidance and obstacle avoidance are achieved in both static and dynamic environment.
Congested Link Inference Algorithms in Dynamic Routing IP Network
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Yu Chen
2017-01-01
Full Text Available The performance descending of current congested link inference algorithms is obviously in dynamic routing IP network, such as the most classical algorithm CLINK. To overcome this problem, based on the assumptions of Markov property and time homogeneity, we build a kind of Variable Structure Discrete Dynamic Bayesian (VSDDB network simplified model of dynamic routing IP network. Under the simplified VSDDB model, based on the Bayesian Maximum A Posteriori (BMAP and Rest Bayesian Network Model (RBNM, we proposed an Improved CLINK (ICLINK algorithm. Considering the concurrent phenomenon of multiple link congestion usually happens, we also proposed algorithm CLILRS (Congested Link Inference algorithm based on Lagrangian Relaxation Subgradient to infer the set of congested links. We validated our results by the experiments of analogy, simulation, and actual Internet.
Decentralized Control of Dynamic Routing with a Neural Network Algorithm
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
A state-dependent routing algorithm based on the neural network model, which takes advantage of other dynamic routing algorithm for circuit-switched network, is given in [1]. But, the Algorithm in [1] is a centralized control model with complex O (N7), therefore, is difficult to realize by hardware. A simplified algorithm is put forward in this paper, in which routing can be controlled decentralizedly, and its complexity is reduced to O (10N3). Computer simulations are made in a fully connected test network with eight nodes. The results show that the centralized control model has very effective performance that can match RTNR, and the centralized control model is not as good as the centralized one but better than DAR-1.
von Thienen, Wolfhard; Metzler, Dirk; Witte, Volker
2015-05-07
The emergence of self-organizing behavior in ants has been modeled in various theoretical approaches in the past decades. One model explains experimental observations in which Argentine ants (Linepithema humile) selected the shorter of two alternative paths from their nest to a food source (shortest path experiments). This model serves as an important example for the emergence of collective behavior and self-organization in biological systems. In addition, it inspired the development of computer algorithms for optimization problems called ant colony optimization (ACO). In the model, a choice function describing how ants react to different pheromone concentrations is fundamental. However, the parameters of the choice function were not deduced experimentally but freely adapted so that the model fitted the observations of the shortest path experiments. Thus, important knowledge was lacking about crucial model assumptions. A recent study on the Argentine ant provided this information by measuring the response of the ants to varying pheromone concentrations. In said study, the above mentioned choice function was fitted to the experimental data and its parameters were deduced. In addition, a psychometric function was fitted to the data and its parameters deduced. Based on these findings, it is possible to test the shortest path model by applying realistic parameter values. Here we present the results of such tests using Monte Carlo simulations of shortest path experiments with Argentine ants. We compare the choice function and the psychometric function, both with parameter values deduced from the above-mentioned experiments. Our results show that by applying the psychometric function, the shortest path experiments can be explained satisfactorily by the model. The study represents the first example of how psychophysical theory can be used to understand and model collective foraging behavior of ants based on trail pheromones. These findings may be important for other
A practical interconnection network RP(k) and its routing algorithms
Institute of Scientific and Technical Information of China (English)
刘方爱; 刘志勇; 乔香珍
2001-01-01
Based on Petersen graph, a new interconnection network, the RP(k) network, is developed and the properties of the RP(k) network are investigated. The diameter of the RP(k) network is [ k/2] + 2 and its degree is 5. We prove that the diameter of the RP(k) network is much smaller than that of the 2-D Torus network when the number of nodes in interconnection networks is less than or equal to 300. In order to analyze the communication performance in a group of nodes, we propose the concepts of the optimal node groups and the diameter of the optimal node groups. We also show that the diameter of the optimal node groups in the RP(k) network is less than that in the 2-D Torus network. Especially when the number of nodes in an optimal node group is between 6 and 100, the diameter of the optimal node groups in the RP(k) network is half of that in the 2-D Torus network. Furthermore based on the RP(k) network we design a set of routing algorithms which are point-to-point routing, permutation routing, one-to-all routing and all-to-all routing. Their communication efficiencies are [k/2] + 2, k + 5, [k/2] + 2, and k + 5 respectively. The RP(k) network and the routing algorithms can provide efficient communication means for parallel and distributed computer system.
Multilayer Traffic Network Optimized by Multiobjective Genetic Clustering Algorithm
Wen, Feng; Gen, Mitsuo; Yu, Xinjie
This paper introduces a multilayer traffic network model and traffic network clustering method for solving the route selection problem (RSP) in car navigation system (CNS). The purpose of the proposed method is to reduce the computation time of route selection substantially with acceptable loss of accuracy by preprocessing the large size traffic network into new network form. The proposed approach further preprocesses the traffic network than the traditional hierarchical network method by clustering method. The traffic network clustering considers two criteria. We specify a genetic clustering algorithm for traffic network clustering and use NSGA-II for calculating the multiple objective Pareto optimal set. The proposed method can overcome the size limitations when solving route selection in CNS. Solutions provided by the proposed algorithm are compared with the optimal solutions to analyze and quantify the loss of accuracy.
Directory of Open Access Journals (Sweden)
Bokyung Goo
2016-12-01
Full Text Available When a blackout occurs, it is important to reduce the time for power system restoration to minimize damage. For fast restoration, it is important to reduce taking time for the selection of generators, transmission lines and transformers. In addition, it is essential that a determination of a generator start-up sequence (GSS be made to restore the power system. In this paper, we propose the optimal selection of black start units through the generator start-up sequence (GSS to minimize the restoration time using generator characteristic data and the enhanced Dijkstra algorithm. For each restoration step, the sequence selected for the next start unit is recalculated to reflect the system conditions. The proposed method is verified by the empirical Korean power systems.
Directory of Open Access Journals (Sweden)
L.Yang
2015-12-01
Full Text Available Three-dimensional path planning for underwater vehicles is an important problem that focuses on optimizing the route with consideration of various constraints in a complex underwater environment. In this paper, an improved ant colony optimization (IACO algorithm based on pheromone exclusion is proposed to solve the underwater vehicle 3D path planning problem. The IACO algorithm can balance the tasks of exploration and development in the ant search path, and enable the ants in the search process to explore initially and develop subsequently. Then, the underwater vehicle can find the safe path by connecting the chosen nodes of the 3D mesh while avoiding the threat area. This new approach can overcome common disadvantages of the basic ant colony algorithm, such as falling into local extremum, poor quality, and low accuracy. Experimental comparative results demonstrate that this proposed IACO method is more effective and feasible in underwater vehicle 3D path planning than the basic ACO model.
Simulated Annealing Technique for Routing in a Rectangular Mesh Network
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Noraziah Adzhar
2014-01-01
Full Text Available In the process of automatic design for printed circuit boards (PCBs, the phase following cell placement is routing. On the other hand, routing process is a notoriously difficult problem, and even the simplest routing problem which consists of a set of two-pin nets is known to be NP-complete. In this research, our routing region is first tessellated into a uniform Nx×Ny array of square cells. The ultimate goal for a routing problem is to achieve complete automatic routing with minimal need for any manual intervention. Therefore, shortest path for all connections needs to be established. While classical Dijkstra’s algorithm guarantees to find shortest path for a single net, each routed net will form obstacles for later paths. This will add complexities to route later nets and make its routing longer than the optimal path or sometimes impossible to complete. Today’s sequential routing often applies heuristic method to further refine the solution. Through this process, all nets will be rerouted in different order to improve the quality of routing. Because of this, we are motivated to apply simulated annealing, one of the metaheuristic methods to our routing model to produce better candidates of sequence.
Institute of Scientific and Technical Information of China (English)
谭冠政; 贺欢; SLOMAN Aaron
2007-01-01
A novel method for the real-time globally optimal path planning of mobile robots is proposed based on the ant colony system (ACS) algorithm. This method includes three steps: the first step is utilizing the MAKLINK graph theory to establish the free space model of the mobile robot, the second step is utilizing the Dijkstra algorithm to find a sub-optimal collision-free path,and the third step is utilizing the ACS algorithm to optimize the location of the sub-optimal path so as to generate the globally optimal path. The result of computer simulation experiment shows that the proposed method is effective and can be used in the real-time path planning of mobile robots. It has been verified that the proposed method has better performance in convergence speed, solution variation, dynamic convergence behavior, and computational efficiency than the path planning method based on the genetic algorithm with elitist model.
Criteria as a route to the routing algorithm in mesh networks with reduced interference
Directory of Open Access Journals (Sweden)
V. I. Pravda
2012-02-01
Full Text Available The paper presents the development assessment system tracks peredichi information in the mesh network and routing algorithm that uses data evaluation. Using this algorithm reduces the interference in the network and power consumption. Provides resistance to changes in the network.
Routing Protocol Design and Performance Optimization in Cognitive Radio Networks
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Zhenguo Wu
2013-10-01
Full Text Available Routing protocol is an important issue in cognitive radio networks. This paper explored the issues and challenges of routing protocol in cognitive radio network from five aspects: hidden terminal, exposed terminal, deafness, cross-layer design, and topology. The existed protocols are classified by the metrics: the establishment of active routing, cross-layer routing, and network performance indicators. Focusing on analyzing performance of routing protocols and design optimized schemes in cognitive radio networks, the advantage and disadvantage of related work were discussed in detail.
Optimization of Multiple Vehicle Routing Problems using Approximation Algorithms
Nallusamy, R; Dhanalaksmi, R; Parthiban, P
2010-01-01
This paper deals with generating of an optimized route for multiple Vehicle routing Problems (mVRP). We used a methodology of clustering the given cities depending upon the number of vehicles and each cluster is allotted to a vehicle. k- Means clustering algorithm has been used for easy clustering of the cities. In this way the mVRP has been converted into VRP which is simple in computation compared to mVRP. After clustering, an optimized route is generated for each vehicle in its allotted cluster. Once the clustering had been done and after the cities were allocated to the various vehicles, each cluster/tour was taken as an individual Vehicle Routing problem and the steps of Genetic Algorithm were applied to the cluster and iterated to obtain the most optimal value of the distance after convergence takes place. After the application of the various heuristic techniques, it was found that the Genetic algorithm gave a better result and a more optimal tour for mVRPs in short computational time than other Algorit...
Optimal learning paths in information networks.
Rodi, G C; Loreto, V; Servedio, V D P; Tria, F
2015-06-01
Each sphere of knowledge and information could be depicted as a complex mesh of correlated items. By properly exploiting these connections, innovative and more efficient navigation strategies could be defined, possibly leading to a faster learning process and an enduring retention of information. In this work we investigate how the topological structure embedding the items to be learned can affect the efficiency of the learning dynamics. To this end we introduce a general class of algorithms that simulate the exploration of knowledge/information networks standing on well-established findings on educational scheduling, namely the spacing and lag effects. While constructing their learning schedules, individuals move along connections, periodically revisiting some concepts, and sometimes jumping on very distant ones. In order to investigate the effect of networked information structures on the proposed learning dynamics we focused both on synthetic and real-world graphs such as subsections of Wikipedia and word-association graphs. We highlight the existence of optimal topological structures for the simulated learning dynamics whose efficiency is affected by the balance between hubs and the least connected items. Interestingly, the real-world graphs we considered lead naturally to almost optimal learning performances.
Optimizing neural network forecast by immune algorithm
Institute of Scientific and Technical Information of China (English)
YANG Shu-xia; LI Xiang; LI Ning; YANG Shang-dong
2006-01-01
Considering multi-factor influence, a forecasting model was built. The structure of BP neural network was designed, and immune algorithm was applied to optimize its network structure and weight. After training the data of power demand from the year 1980 to 2005 in China, a nonlinear network model was obtained on the relationship between power demand and the factors which had impacts on it, and thus the above proposed method was verified. Meanwhile, the results were compared to those of neural network optimized by genetic algorithm. The results show that this method is superior to neural network optimized by genetic algorithm and is one of the effective ways of time series forecast.
Max-min Fair Rate Allocation and Routing in Energy Harvesting Networks: Algorithmic Analysis
Marasevic, Jelena; Stein, Cliff; Zussman, Gil
2014-01-01
This paper considers max-min fair rate allocation and routing in energy harvesting networks where fairness is required among both the nodes and the time slots. Unlike most previous work on fairness, we focus on multihop topologies and consider different routing methods. We assume a predictable energy profile and focus on the design of efficient and optimal algorithms that can serve as benchmarks for distributed and approximate algorithms. We first develop an algorithm that obtains a max-min f...
Approximate shortest homotopic paths in weighted regions
Cheng, Siuwing
2012-02-01
A path P between two points s and t in a polygonal subdivision T with obstacles and weighted regions defines a class of paths that can be deformed to P without passing over any obstacle. We present the first algorithm that, given P and a relative error tolerance ε (0, 1), computes a path from this class with cost at most 1 + ε times the optimum. The running time is O(h 3/ε 2kn polylog (k,n,1/ε)), where k is the number of segments in P and h and n are the numbers of obstacles and vertices in T, respectively. The constant in the running time of our algorithm depends on some geometric parameters and the ratio of the maximum region weight to the minimum region weight. © 2012 World Scientific Publishing Company.
Approximate Shortest Homotopic Paths in Weighted Regions
Cheng, Siu-Wing
2010-01-01
Let P be a path between two points s and t in a polygonal subdivision T with obstacles and weighted regions. Given a relative error tolerance ε ∈(0,1), we present the first algorithm to compute a path between s and t that can be deformed to P without passing over any obstacle and the path cost is within a factor 1 + ε of the optimum. The running time is O(h 3/ε2 kn polylog(k, n, 1/ε)), where k is the number of segments in P and h and n are the numbers of obstacles and vertices in T, respectively. The constant in the running time of our algorithm depends on some geometric parameters and the ratio of the maximum region weight to the minimum region weight. © 2010 Springer-Verlag.
Accident Emergency Response And Routing Software (AERARS using Genetic Algorithm
Directory of Open Access Journals (Sweden)
Naveen Ramachandran,
2011-07-01
Full Text Available AERARS is a response and routing software for accident emergency requirement. A method has been proposed in this project for using a genetic algorithm to find the shortest route between a source and adestination. It make use of genetic algorithms ability to search the opt solution from the population helping to solve spatially addressed problem. The numbers of accident spots are plotted in ArcGISenvironment and ten major accident spots are identified. The software package is designed with closest facility estimation and shortest route generation along with other basic software facilities in Visual Basic environment. Genetic algorithm provided a great optimality to the solutions. The closest facility tool helps to estimate the nearest hospital, ambulance, police station and fire station. The shortest route estimation tool generates shortest path between a locations to the hospital or ambulance spot. The various risk zonesare assessed and more safety measures can be taken to reduce the frequency of accident. The software efficiency can be further increased by incorporating GPS and satellite technology.
A priori least expected time paths in fuzzy, time-variant transportation networks
Wang, Li; Gao, Ziyou; Yang, Lixing
2016-02-01
Dynamics and fuzziness are two significant characteristics of real-world transportation networks. To capture these two features theoretically, this article proposes the concept of a fuzzy, time-variant network characterized by a series of time-dependent fuzzy link travel times. To find an effective route guidance for travelers, the expected travel time is specifically adopted as an evaluation criterion to assess the route generation process. Then the shortest path problem is formulated as a multi-objective 0-1 optimization model for finding the least expected time path over the considered time horizon. Different from the shortest path problem in dynamic and random networks, an efficient method is proposed in this article to calculate the fuzzy expected travel time for each given path. A tabu search algorithm is designed for the problem to generate the best solution under the framework of linear weighted methods. Finally, two numerical experiments are performed to verify the effectiveness and efficiency of the model and algorithm.
Routing in Wireless Sensor Networks Using an Ant Colony Optimization (ACO) Router Chip
Dervis Karaboga; Selcuk Okdem
2009-01-01
Wireless Sensor Networks consisting of nodes with limited power are deployed to gather useful information from the field. In WSNs it is critical to collect the information in an energy efficient manner. Ant Colony Optimization, a swarm intelligence based optimization technique, is widely used in network routing. A novel routing approach using an Ant Colony Optimization algorithm is proposed for Wireless Sensor Networks consisting of stable nodes. Illustrative examples, detailed descriptions a...
UMR: A utility-maximizing routing algorithm for delay-sensitive service in LEO satellite networks
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Lu Yong
2015-04-01
Full Text Available This paper develops a routing algorithm for delay-sensitive packet transmission in a low earth orbit multi-hop satellite network consists of micro-satellites. The micro-satellite low earth orbit (MS-LEO network endures unstable link connection and frequent link congestion due to the uneven user distribution and the link capacity variations. The proposed routing algorithm, referred to as the utility maximizing routing (UMR algorithm, improve the network utility of the MS-LEO network for carrying flows with strict end-to-end delay bound requirement. In UMR, first, a link state parameter is defined to capture the link reliability on continuing to keep the end-to-end delay into constraint; then, on the basis of this parameter, a routing metric is formulated and a routing scheme is designed for balancing the reliability in delay bound guarantee among paths and building a path maximizing the network utility expectation. While the UMR algorithm has many advantages, it may result in a higher blocking rate of new calls. This phenomenon is discussed and a weight factor is introduced into UMR to provide a flexible performance option for network operator. A set of simulations are conducted to verify the good performance of UMR, in terms of balancing the traffic distribution on inter-satellite links, reducing the flow interruption rate, and improving the network utility.
Route Optimization of Stacker in Automatic Warehouse Based on Genetic Algorithm
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Cui Changqing
2013-11-01
Full Text Available Today, automatic warehouse system gradually replaced manual labor, and played an important role in the production work, especially in the cargo handling work. It was important to research the time-consuming and efficiency of stacker in the automated warehouse system. This paper researched the path of stacker in automated warehouse and calculated the operation time of stacker working path according to actual working condition, and then put forward a route optimization method of stacker based on genetic algorithm, finally simulated this algorithm by using MATLAB. The simulation results showed that this algorithm could shorten the way of stacker, and increase the working efficiency of the warehouse.
Pheromone-Based Ant Routing System for IP Networks
Institute of Scientific and Technical Information of China (English)
张林; 任勇; 山秀明
2004-01-01
The pheromone-based ant routing algorithm is a distributed routing algorithm with good scalability and robustness. A 2-D cellular automata (CA) model of the computer network was presented to analyze the algorithm. The results show that the procedure of establishing a stable route is self-organized towards the attractive peculiar state, and the duration of time for the routing establishment is power-law distributed. A practical ant routing protocol over an IP network was also presented, and two simulations were done to compare the performance dynamic and the load balancing performance between this protocol and the open shortest path first (OSPF) protocol. The results show that the ant routing protocol out-performs OSPF in these aspects.
Energy-Aware Routing Optimization in Dynamic GMPLS Controlled Optical Networks
DEFF Research Database (Denmark)
Wang, Jiayuan; Ricciardi, Sergio; Fagertun, Anna Manolova;
2012-01-01
In this paper, routing optimizations based on energy sources are proposed in dynamic GMPLS controlled optical networks. The influences of re-routing and load balancing factors on the algorithm are evaluated, with a focus on different re-routing thresholds. Results from dynamic network simulations...... show that re-routing strategies can lower CO2 emissions compared to the basic energy source routing scheme, and a lower re-routing threshold achieves more savings. The increased blocking probability brought by using re-routing schemes can be compensated by applying load balancing criteria. A trade...
Reliable routing algorithm in marine ad hoc networks
Institute of Scientific and Technical Information of China (English)
LIN Wei; YANG Yong-Tian
2004-01-01
A routing algorithm called DNH for increasing efficiency of mobile ad hoc network is presented, which is based on a new criterion called TSS ( Temporarily Steady State) , combining with wireless transmission theory that makes networks topology correspondingly stabilization. Also the DNH algorithm has the characteristics of giving up queuing in a node, but selecting another idle node instead of the node for forwarding data packets if the node has a full throughput. Simulation evaluation shows that selecting another node is better than queuing in a full throughout node if some conditions are satisfied, especially during a sea battle, every warship in ad hoc network wants to contest time and increase propagation reliability. The DNH algorithm can help decrease routing time, and raise efficiency of marine ad hoc networks.
High throughput route selection in multi-rate wireless mesh networks
Institute of Scientific and Technical Information of China (English)
WEI Yi-fei; GUO Xiang-li; SONG Mei; SONG Jun-de
2008-01-01
Most existing Ad-hoc routing protocols use the shortest path algorithm with a hop count metric to select paths. It is appropriate in single-rate wireless networks, but has a tendency to select paths containing long-distance links that have low data rates and reduced reliability in multi-rate networks. This article introduces a high throughput routing algorithm utilizing the multi-rate capability and some mesh characteristics in wireless fidelity (WiFi) mesh networks. It uses the medium access control (MAC) transmission time as the routing metric, which is estimated by the information passed up from the physical layer. When the proposed algorithm is adopted, the Ad-hoc on-demand distance vector (AODV) routing can be improved as high throughput AODV (HT-AODV). Simulation results show that HT-AODV is capable of establishing a route that has high data-rate, short end-to-end delay and great network throughput.
Directory of Open Access Journals (Sweden)
Jing Yang
2010-05-01
Full Text Available For monitoring burst events in a kind of reactive wireless sensor networks (WSNs, a multipath routing protocol (MRP based on dynamic clustering and ant colony optimization (ACO is proposed.. Such an approach can maximize the network lifetime and reduce the energy consumption. An important attribute of WSNs is their limited power supply, and therefore some metrics (such as energy consumption of communication among nodes, residual energy, path length were considered as very important criteria while designing routing in the MRP. Firstly, a cluster head (CH is selected among nodes located in the event area according to some parameters, such as residual energy. Secondly, an improved ACO algorithm is applied in the search for multiple paths between the CH and sink node. Finally, the CH dynamically chooses a route to transmit data with a probability that depends on many path metrics, such as energy consumption. The simulation results show that MRP can prolong the network lifetime, as well as balance of energy consumption among nodes and reduce the average energy consumption effectively.
Directory of Open Access Journals (Sweden)
Jing Yang
2009-10-01
Full Text Available For monitoring burst events in a kind of reactive wireless sensor networks (WSNs, a multipath routing protocol (MRP based on dynamic clustering and ant colony optimization (ACO is proposed.. Such an approach can maximize the network lifetime and reduce the energy consumption. An important attribute of WSNs is its limited power supply, and therefore in MRP, some metrics (such as energy consumption of communication among nodes, residual energy, path length are considered as very important criteria while designing routing. Firstly, a cluster head (CH is selected among nodes located in the event area according to some parameters, such as residual energy. Secondly, an improved ACO algorithm is applied in search for multiple paths between the CH and sink node. Finally, the CH dynamically chooses a route to transmit data with a probability that depends on many path metrics, such as energy consumption. The simulation results show that MRP can prolong the network lifetime, as well as balance energy consumption among nodes and reduce the average energy consumption effectively.
A distributed routing algorithm for data aggregation in wireless sensor networks
Institute of Scientific and Technical Information of China (English)
Hong LUO; Fangchun YANG; Yonghe LIU
2008-01-01
Considering the impact of aggregation cost on the performance of aggregation routes in wireless sensor networks, an aggregation-decision-based distributed rout-ing algorithm for data aggregation is proposed. When source nodes arrive or leave, the algorithm can calculate the aggregation benefit according to data correlation, aggregation cost and transmission cost. Then the algo-rithm will adaptively make aggregation and routing decisions based on aggregation benefit. Therefore, it can jointly optimize the aggregation and transmission costs and reduce the energy consumption for data gathering. This distributed algorithm makes all the decisions only relying on the local information. Hence, the routing maintenance cost is limited. Simulation results show that the energy consumption difference between this distrib-uted online algorithm and the previous offilne one is within 17% under any network conditions.
Traffic resource allocation for complex networks
Institute of Scientific and Technical Information of China (English)
Ling Xiang; Hu Mao-Bin; Long Jian-Cheng; Ding Jian-Xun; Shi Qin
2013-01-01
In this paper,an optimal resource allocation strategy is proposed to enhance traffic dynamics in complex networks.The network resources are the total node packet-delivering capacity and the total link bandwidth.An analytical method is developed to estimate the overall network capacity by using the concept of efficient betweenness (ratio of algorithmic betweenness and local processing capacity).Three network structures (scale-free,small-world,and random networks) and two typical routing protocols (shortest path protocol and efficient routing protocol) are adopted to demonstrate the performance of the proposed strategy.Our results show that the network capacity is reversely proportional to the average path length for a particular routing protocol and the shortest path protocol can achieve the largest network capacity when the proposed resource allocation strategy is adopted.
Intelligent QoS routing algorithm based on improved AODV protocol for Ad Hoc networks
Huibin, Liu; Jun, Zhang
2016-04-01
Mobile Ad Hoc Networks were playing an increasingly important part in disaster reliefs, military battlefields and scientific explorations. However, networks routing difficulties are more and more outstanding due to inherent structures. This paper proposed an improved cuckoo searching-based Ad hoc On-Demand Distance Vector Routing protocol (CSAODV). It elaborately designs the calculation methods of optimal routing algorithm used by protocol and transmission mechanism of communication-package. In calculation of optimal routing algorithm by CS Algorithm, by increasing QoS constraint, the found optimal routing algorithm can conform to the requirements of specified bandwidth and time delay, and a certain balance can be obtained among computation spending, bandwidth and time delay. Take advantage of NS2 simulation software to take performance test on protocol in three circumstances and validate the feasibility and validity of CSAODV protocol. In results, CSAODV routing protocol is more adapt to the change of network topological structure than AODV protocol, which improves package delivery fraction of protocol effectively, reduce the transmission time delay of network, reduce the extra burden to network brought by controlling information, and improve the routing efficiency of network.
A Hybrid Routing Algorithm Based on Ant Colony and ZHLS Routing Protocol for MANET
Rafsanjani, Marjan Kuchaki; Asadinia, Sanaz; Pakzad, Farzaneh
Mobile Ad hoc networks (MANETs) require dynamic routing schemes for adequate performance. This paper, presents a new routing algorithm for MANETs, which combines the idea of ant colony optimization with Zone-based Hierarchical Link State (ZHLS) protocol. Ant colony optimization (ACO) is a class of Swarm Intelligence (SI) algorithms. SI is the local interaction of many simple agents to achieve a global goal. SI is based on social insect for solving different types of problems. ACO algorithm uses mobile agents called ants to explore network. Ants help to find paths between two nodes in the network. Our algorithm is based on ants jump from one zone to the next zones which contains of the proactive routing within a zone and reactive routing between the zones. Our proposed algorithm improves the performance of the network such as delay, packet delivery ratio and overhead than traditional routing algorithms.
Optimal Reverse Carpooling Over Wireless Networks - A Distributed Optimization Approach
ParandehGheibi, Ali; Effros, Michelle; Medard, Muriel
2010-01-01
We focus on a particular form of network coding, reverse carpooling, in a wireless network where the potentially coded transmitted messages are to be decoded immediately upon reception. The network is fixed and known, and the system performance is measured in terms of the number of wireless broadcasts required to meet multiple unicast demands. Motivated by the structure of the coding scheme, we formulate the problem as a linear program by introducing a flow variable for each triple of connected nodes. This allows us to have a formulation polynomial in the number of nodes. Using dual decomposition and projected subgradient method, we present a decentralized algorithm to obtain optimal routing schemes in presence of coding opportunities. We show that the primal sub-problem can be expressed as a shortest path problem on an \\emph{edge-graph}, and the proposed algorithm requires each node to exchange information only with its neighbors.
Robinson, Y Harold; Rajaram, M
2015-01-01
Mobile ad hoc network (MANET) is a collection of autonomous mobile nodes forming an ad hoc network without fixed infrastructure. Dynamic topology property of MANET may degrade the performance of the network. However, multipath selection is a great challenging task to improve the network lifetime. We proposed an energy-aware multipath routing scheme based on particle swarm optimization (EMPSO) that uses continuous time recurrent neural network (CTRNN) to solve optimization problems. CTRNN finds the optimal loop-free paths to solve link disjoint paths in a MANET. The CTRNN is used as an optimum path selection technique that produces a set of optimal paths between source and destination. In CTRNN, particle swarm optimization (PSO) method is primly used for training the RNN. The proposed scheme uses the reliability measures such as transmission cost, energy factor, and the optimal traffic ratio between source and destination to increase routing performance. In this scheme, optimal loop-free paths can be found using PSO to seek better link quality nodes in route discovery phase. PSO optimizes a problem by iteratively trying to get a better solution with regard to a measure of quality. The proposed scheme discovers multiple loop-free paths by using PSO technique.
Energy-Aware Multipath Routing Scheme Based on Particle Swarm Optimization in Mobile Ad Hoc Networks
Directory of Open Access Journals (Sweden)
Y. Harold Robinson
2015-01-01
Full Text Available Mobile ad hoc network (MANET is a collection of autonomous mobile nodes forming an ad hoc network without fixed infrastructure. Dynamic topology property of MANET may degrade the performance of the network. However, multipath selection is a great challenging task to improve the network lifetime. We proposed an energy-aware multipath routing scheme based on particle swarm optimization (EMPSO that uses continuous time recurrent neural network (CTRNN to solve optimization problems. CTRNN finds the optimal loop-free paths to solve link disjoint paths in a MANET. The CTRNN is used as an optimum path selection technique that produces a set of optimal paths between source and destination. In CTRNN, particle swarm optimization (PSO method is primly used for training the RNN. The proposed scheme uses the reliability measures such as transmission cost, energy factor, and the optimal traffic ratio between source and destination to increase routing performance. In this scheme, optimal loop-free paths can be found using PSO to seek better link quality nodes in route discovery phase. PSO optimizes a problem by iteratively trying to get a better solution with regard to a measure of quality. The proposed scheme discovers multiple loop-free paths by using PSO technique.
Fast estimation of diameter and shortest paths (without matrix multiplication)
Energy Technology Data Exchange (ETDEWEB)
Aingworth, D.; Chekuri, C.; Motwani, R. [Stanford Univ., CA (United States)
1996-12-31
Consider the problem of computing all-pairs shortest paths (APSP) in an unweighted, undirected graph G with n vertices and m edges. The recent work of Alon, Galil, and Margalit, Alon, Galil, Margalit, and Naor, and Seidel has led to dramatic progress in devising fast algorithms for this problem. These algorithm are based on formulating the problem in terms of matrices with small integer entries and using fast matrix multiplications. They achieve a time bound of O(n{sup {omega}}){sup 1} where {omega} denotes the exponent in the running time of the matrix multiplication algorithm used. The current best matrix multiplication algorithm is due to Coppersmith and Winograd [CW90] and has {omega} = 2.376. In contrast, the naive algorithm for APSP performs breadth-first searches from each vertex, and requires time {Theta}(nm).
Ding, Zhe; Xu, Zhanqi; Zeng, Xiaodong; Ma, Tao; Yang, Fan
2014-04-01
By adopting the orthogonal frequency division multiplexing technology, spectrum-sliced elastic optical path networks can offer flexible bandwidth to each connection request and utilize the spectrum resources efficiently. The routing and spectrum assignment (RSA) problems in SLICE networks are solved by using heuristic algorithms in most prior studies and addressed by intelligent algorithms in few investigations. The performance of RSA algorithms can be further improved if we could combine such two types of algorithms. Therefore, we propose three hybrid RSA algorithms: DACE-GMSF, DACE-GLPF, and DACE-GEMkPSF, which are the combination of the heuristic algorithm and coevolution based on distance-adaptive policy. In the proposed algorithms, we first groom the connection requests, then sort the connection requests by using the heuristic algorithm (most subcarriers first, longest path first, and extended most k paths' slots first), and finally search the approximately optimal solution with the coevolutionary policy. We present a model of the RSA problem by using integral linear programming, and key elements in the proposed algorithms are addressed in detail. Simulations under three topologies show that the proposed hybrid RSA algorithms can save spectrum resources efficiently.
About Testing the Speed of Calculating the Shortest Route
Directory of Open Access Journals (Sweden)
Tiberiu Marius Karnyanszky
2008-01-01
Full Text Available Applied into a various area of domains, the graph theory and its applications allow the determination of the shortest route. The common algorithm to solve this problem is Bellman-Kalaba, based on the matrix multiplying operation. If the graph is very large (e.g., the dimension of the associated incidence matrix is big, one of the main problems is to reduce the calculus time. This paper presents a testing method able to analyze if an acceleration of the Bellman-Kalaba is possible and able to determine the time efficiency.
Application Oriented Flow Routing Algorithm for VoIP Overlay Networks
Wipusitwarakun, Komwut; Chimmanee, Sanon
Overlay networks which are dynamically created over underlying IP networks are becoming widely used for delivering multimedia contents since they can provide several additional user-definable services. Multiple overlay paths between a source-destination overlay node pair are designed to improve service robustness against failures and bandwidth fluctuation of the underlying networks. Multimedia traffic can be distributed over those multiple paths in order to maximize paths' utilization and to increase application throughputs. Most of flow-based routing algorithms consider only common metrics such as paths' bandwidth or delay, which may be effective for data applications but not for real-time applications such as Voice over IP (VoIP), in which different levels of such performance metrics may give the same level of the performance experienced by end users. This paper focuses on such VoIP overlay networks and proposes a novel alternative path based flow routing algorithm using an application-specific traffic metric, i.e. “VoIP Path Capacity (VPCap), ” to calculate the maximum number of QoS satisfied VoIP flows which may be distributed over each available overlay path at a moment. The simulation results proved that more QoS-satisfied VoIP sessions can be established over the same multiple overlay paths, comparing to traditional approaches.
A NEW ROUTING ALGORITHM FOR THE SHUFFLE-EXCHANGE PERMUTATION NETWORK
Institute of Scientific and Technical Information of China (English)
Baoxing CHEN; Wenjun XIAO; Ni DU
2006-01-01
In this paper, a new routing algorithm is given for the shuffle-exchange permutation network (SEPn). The length of the path between any two nodes given by our algorithm is not more than 11/16n2 +O(n), i.e., the diameter of SEPn is at most 11/16n2+O(n). This improves on a 1/8(9n2 -22n+24)routing algorithm described earlier by S. Latifi and P. K. Srimani. We also show that the diameter of SEPn is more than 1/2n2-n.
An Energy-Aware Multipath Routing Algorithm in Wireless Sensor Networks
Kim, Moonseong; Jeong, Euihoon; Bang, Young-Cheol; Hwang, Soyoung; Shin, Changsub; Jin, Gwang-Ja; Kim, Bongsoo
One of the major challenges facing the design of a routing protocol for Wireless Sensor Networks (WSNs) is to find the most reliable path between the source and sink node. Furthermore, a routing protocol for WSN should be well aware of sensor limitations. In this paper, we present an energy efficient, scalable, and distributed node disjoint multipath routing algorithm. The proposed algorithm, the Energy-aware Multipath Routing Algorithm (EMRA), adjusts traffic flows via a novel load balancing scheme. EMRA has a higher average node energy efficiency, lower control overhead, and a shorter average delay than those of well-known previous works. Moreover, since EMRA takes into consideration network reliability, it is useful for delivering data in unreliable environments.
Resource-efficient path-protection schemes and online selection of routes in reliable WDM networks
Monti, Paolo; Tacca, Marco; Fumagalli, Andrea
2004-04-01
The optimal choice of routing and wavelength assignment (RWA) for the working and protection path-pair of the newly generated demand request is often a complex problem in reliable wavelength-division-multiplexed (WDM) networks subject to dynamic traffic. The challenge is twofold: how to provide the required reliability level without over-reserving network resources and how to find a good solution of the RWA problem under constrained computational time. Two important contributions are made. First, the shared path protection (SPP) switching scheme is generalized to guarantee the required (differentiated) level of reliability to all arriving demands, while, at the same time, ensuring that they contain the required amount of reserved network resources. This generalization is referred to as SPP-DiR. Second, an approach for choosing the working and protection path-pair routing for the arriving demand is proposed. The approach is based on a matrix of preselected path-pairs: the disjoint path-pair matrix (DPM). Results show that, when the SPP-DiR scheme is applied, a small reduction in demand reliability corresponds to a significant reduction of the required network resources, when compared with the conventional SPP. In turn, the demand blocking probability may be reduced more than one order of magnitude. It is also shown that the DPM approach is suitable for obtaining satisfactory RWA solutions in both SPP-DiR and conventional SPP networks. The use of the DPM is most suited when the time for solving the RWA problem is constrained, e.g., when demand requests must be served swiftly.
On the existence of shortest directed networks
Swanepoel, Konrad J
2008-01-01
A directed network connecting a set A to a set B is a digraph containing an a-b path for each a in A and b in B. Vertices in the directed network not in A or B are called Steiner points. We show that in a finitely compact metric space in which geodesics exist, any two finite sets A and B are connected by a shortest directed network. We also bound the number of Steiner points by a function of the sizes of A and B. Previously, such an existence result was known only for the Euclidean plane [M. Alfaro, Pacific J. Math. 167 (1995) 201-214]. The main difficulty is that, unlike the undirected case (Steiner minimal trees), the underlying graphs need not be acyclic. Existence in the undirected case was first shown by E. J. Cockayne [Canad. Math. Bull. 10 (1967) 431-450].
Effective Hierarchical Routing Algorithm for Large-scale Wireless Mobile Networks
Directory of Open Access Journals (Sweden)
Guofeng Yan
2014-02-01
Full Text Available The growing interest in wireless mobile network techniques has resulted in many routing protocol proposals. The unpredictable motion and the unreliable behavior of mobile nodes is one of the key issues in wireless mobile network. Virtual mobile node (VMN consists of robust virtual nodes that are both predictable and reliable. Based on VMN, in this paper, we present a hierarchical routing algorithm, i.e., EHRA-WAVE, for large-scale wireless mobile networks. By using mobile WAVE technology, a routing path can be found rapidly between VMNs without accurate topology information. We introduce the routing algorithm and the implementation issues of the proposed EHRA-WAVE routing algorithm. Finally, we evaluate the performance of EHRA-WAVE through experiments, and compare the performance on VMN failure and message delivery ratio using hierarchical and non-hierarchical routing methods. However, due to the large amounts WAVE flooding, EHRAWAVE results in too large load which would impede the application of the EHRA-WAVE algorithm. Therefore, the further routing protocol focuses on minimizing the number of WAVE using hierarchical structures in large-scale wireless mobile networks.
Algorithm of capacity expansion on networks optimization
Institute of Scientific and Technical Information of China (English)
无
2003-01-01
The paper points out the relationship between the bottleneck and the minimum cutset of the network, and presents a capacity expansion algorithm of network optimization to solve the network bottleneck problem. The complexity of the algorithm is also analyzed. As required by the algorithm, some virtual sources are imported through the whole positive direction subsection in the network, in which a certain capacity value is given. Simultaneously, a corresponding capacity-expanded network is constructed to search all minimum cutsets. For a given maximum flow value of the network, the authors found an adjustment value of each minimum cutset arc's group with gradually reverse calculation and marked out the feasible flow on the capacity-extended networks again with the adjustment value increasing. All this has been done repeatedly until the original topology structure is resumed. So the algorithm can increase the capacity of networks effectively and solve the bottleneck problem of networks.
Secure Multicast Routing Algorithm for Wireless Mesh Networks
Directory of Open Access Journals (Sweden)
Rakesh Matam
2016-01-01
Full Text Available Multicast is an indispensable communication technique in wireless mesh network (WMN. Many applications in WMN including multicast TV, audio and video conferencing, and multiplayer social gaming use multicast transmission. On the other hand, security in multicast transmissions is crucial, without which the network services are significantly disrupted. Existing secure routing protocols that address different active attacks are still vulnerable due to subtle nature of flaws in protocol design. Moreover, existing secure routing protocols assume that adversarial nodes cannot share an out-of-band communication channel which rules out the possibility of wormhole attack. In this paper, we propose SEMRAW (SEcure Multicast Routing Algorithm for Wireless mesh network that is resistant against all known active threats including wormhole attack. SEMRAW employs digital signatures to prevent a malicious node from gaining illegitimate access to the message contents. Security of SEMRAW is evaluated using the simulation paradigm approach.
Directory of Open Access Journals (Sweden)
K. Duraiswamy
2012-01-01
Full Text Available The moving object or vehicle location prediction based on their spatial and temporal information is an important task in many applications. Different methods were utilized for performing the vehicle movement detection and prediction process. In such works, there is a lack of analysis in predicting the vehicles location in current as well as in future. Moreover, such methods compute the vehicles movement by finding the topological relationships among trajectories and locations, whereas the representative GPS points are determined by the 30 m circular window. Due to this process, the performance of the method is degraded because such 30 m circular window is selected by calculating the error range in the given input image and such error range may vary from image to image. To reduce the drawback presented in the existing method, in this study a heuristic moving vehicle location prediction algorithm is proposed. The proposed heuristic algorithm mainly comprises two techniques namely, optimization GA algorithm and FFBNN. In this proposed technique, initially the vehicles frequent paths are collected by monitoring all the vehicles movement in a specific period. Among the frequent paths, the vehicles optimal paths are computed by the GA algorithm. The selected optimal paths for each vehicle are utilized to train the FFBNN. The well trained FFBNN is then utilized to find the vehicle movement from the current location. By combining the proposed heuristic algorithm with GA and FFBNN, the vehicles location is predicted efficiently. The implementation result shows the effectiveness of the proposed heuristic algorithm in predicting the vehicles future location from the current location. The performance of the heuristic algorithm is evaluated by comparing the result with the RBF classifier. The comparison result shows our proposed technique acquires an accurate vehicle location prediction ratio than the RBF prediction ratio, in terms of accuracy.
Directory of Open Access Journals (Sweden)
L. Keerthana
2012-06-01
Full Text Available A Strategy of Multispanning Tree Zone Ordered Label Based routing is improved with Efficient and Reliable (EAR routing for irregular networks is presented and analyzed in this work. Most existing deadlock free routing methods for irregular topologies impose several limitations on node and channel labeling in an irregular network is based on a pre-defined spanning tree.It is not possible to form a deadlock free zone of three or four channel labels for two spanning tree. So this existing Multispanning Tree Zone Ordered Label Based routing is modified with Efficient and Reliable (EAR routing. EAR is based on four parameters length of the path,distance traversed,transmission of link and energy levels to dynamically determine and maintain the best routes.. The simulation results have shown highest packet delivery ratio, minimum latency, and energy consumption.
The role of convexity for solving some shortest path problems in plane without triangulation
An, Phan Thanh; Hai, Nguyen Ngoc; Hoai, Tran Van
2013-09-01
Solving shortest path problems inside simple polygons is a very classical problem in motion planning. To date, it has usually relied on triangulation of the polygons. The question: "Can one devise a simple O(n) time algorithm for computing the shortest path between two points in a simple polygon (with n vertices), without resorting to a (complicated) linear-time triangulation algorithm?" raised by J. S. B. Mitchell in Handbook of Computational Geometry (J. Sack and J. Urrutia, eds., Elsevier Science B.V., 2000), is still open. The aim of this paper is to show that convexity contributes to the design of efficient algorithms for solving some versions of shortest path problems (namely, computing the convex hull of a finite set of points and convex rope on rays in 2D, computing approximate shortest path between two points inside a simple polygon) without triangulation on the entire polygons. New algorithms are implemented in C and numerical examples are presented.
All-Pairs Shortest Paths in $O(n^2)$ time with high probability
Peres, Yuval; Sudakov, Benny; Zwick, Uri
2011-01-01
We present an all-pairs shortest path algorithm whose running time on a complete directed graph on $n$ vertices whose edge weights are chosen independently and uniformly at random from $[0,1]$ is $O(n^2)$, in expectation and with high probability. This resolves a long standing open problem. The algorithm is a variant of the dynamic all-pairs shortest paths algorithm of Demetrescu and Italiano. The analysis relies on a proof that the number of \\emph{locally shortest paths} in such randomly weighted graphs is $O(n^2)$, in expectation and with high probability. We also present a dynamic version of the algorithm that recomputes all shortest paths after a random edge update in $O(\\log^{2}n)$ expected time.
Survivable Lightpath Routing in WDM Optical Networks
Institute of Scientific and Technical Information of China (English)
LIUFengqing; ZENGQingji; ZHUXu; YANGXudong; XIAOShilin
2004-01-01
In IP over WDM networks, when a failure(such as a fiber cut) occurs, the service restoration can be implemented by dynamic routing in IP layer. But it needs that the logical topology remains connected after any physical link failure. Otherwise, IP layer cannot find an alternate path to restore the service. The problem of routing logical links (lightpaths) on a physical network topology in a way that the logical topology remains connected in the event of single physical link failure is called survivabl erouting. In this paper~ we address the survivable routing problem by proposing a new ILP algorithm that works well with sparse-connected logical topologies. The necessary and sufficient conditions for survivable routing are simplified, which greatly reduces the number of survivable constraints. Based-on the simplified conditions, a new ILP formulation with K-shortest paths as alternate paths for a logical link is presented, which mainly reduces the number of ILP variables. Finally, numerical results are given and discussed to show that most survivable routing solutions can be found with our algorithms, and the time needed to find such a survivable routing solution is much smaller than other similar methods.
Optimizing Route for Hazardous Materials Logistics Based on Hybrid Ant Colony Algorithm
Directory of Open Access Journals (Sweden)
Haixing Wang
2013-01-01
Full Text Available Optimizing Route for Hazardous Materials Logistics (ORHML belongs to a class of problems referred to as NP-Hard, and a strict constraint of it makes it harder to solve. In order to dealing with ORHML, an improved hybrid ant colony algorithm (HACA was devised. To achieve the purpose of balancing risk and cost for route based on the principle of ACA that used to solve TSP, the improved HACA was designed. Considering the capacity of road network and the maximum expected risk limits, a route optimization model to minimize the total cost is established based on network flow theory. Improvement on route construction rule and pheromone updating rule was adopted on the basis of the former algorithm. An example was analyzed to demonstrate the correctness of the application. It is proved that improved HACA is efficient and feasible in solving ORHML.
Network Routing Using the Network Tasking Order, a Chron Approach
2015-03-26
Mobile Ad hoc Networks ( MANET ). The network topology created by airborne platforms is determined ahead of time and network transitions are calculated...scheduling and splitting network traffic over an emulated MANET compared to Open Shortest Path First (OSPF) which only achieved around a 71% success rate...13 2.4 MANET Prediction Routing .............................................................................14 2.4.1
A Graph Search Heuristic for Shortest Distance Paths
Energy Technology Data Exchange (ETDEWEB)
Chow, E
2005-03-24
This paper presents a heuristic for guiding A* search for finding the shortest distance path between two vertices in a connected, undirected, and explicitly stored graph. The heuristic requires a small amount of data to be stored at each vertex. The heuristic has application to quickly detecting relationships between two vertices in a large information or knowledge network. We compare the performance of this heuristic with breadth-first search on graphs with various topological properties. The results show that one or more orders of magnitude improvement in the number of vertices expanded is possible for large graphs, including Poisson random graphs.
Performance Analysis of Node-Disjoint Paths in Multipath Routing for Wireless Sensor Networks
Murthy, G. Shiva; D'Souza, R. J.; Varaprasad, G.
2011-12-01
Routing in the resource constrained network is still a challenge. To increase the operational lifetme of the wireless senor networks is the major objective of energy efficeint routing protocols. Multipath routing protocols increases the QoS, network reliability, and lifetime. This work analyses the node-dsijoint paths which contribute in realising the objectives of mutlipath routing. This work proposes the three different criteria to select the node-disjoint paths between the source and sink node. They are (i) minimum hop (ii) maximum residual energy and (iii) maximum path cost. End to end delay, residual energy and throughput are the metrics considered to evaluate the performance of three different criteria to select node-disjoint paths between source and destination.
Deterministic Agent-Based Path Optimization by Mimicking the Spreading of Ripples.
Hu, Xiao-Bing; Wang, Ming; Leeson, Mark S; Di Paolo, Ezequiel A; Liu, Hao
2016-01-01
Inspirations from nature have contributed fundamentally to the development of evolutionary computation. Learning from the natural ripple-spreading phenomenon, this article proposes a novel ripple-spreading algorithm (RSA) for the path optimization problem (POP). In nature, a ripple spreads at a constant speed in all directions, and the node closest to the source is the first to be reached. This very simple principle forms the foundation of the proposed RSA. In contrast to most deterministic top-down centralized path optimization methods, such as Dijkstra's algorithm, the RSA is a bottom-up decentralized agent-based simulation model. Moreover, it is distinguished from other agent-based algorithms, such as genetic algorithms and ant colony optimization, by being a deterministic method that can always guarantee the global optimal solution with very good scalability. Here, the RSA is specifically applied to four different POPs. The comparative simulation results illustrate the advantages of the RSA in terms of effectiveness and efficiency. Thanks to the agent-based and deterministic features, the RSA opens new opportunities to attack some problems, such as calculating the exact complete Pareto front in multiobjective optimization and determining the kth shortest project time in project management, which are very difficult, if not impossible, for existing methods to resolve. The ripple-spreading optimization principle and the new distinguishing features and capacities of the RSA enrich the theoretical foundations of evolutionary computation.
Directory of Open Access Journals (Sweden)
Reza Dovlatabadi
Full Text Available One of the most important factors in wireless sensor networks is energy consumption, hence the lifetime of these networks are strongly depending on remaining energy in the nodes. According to sensors placement farness and wireless communication between th ...
The production route selection algorithm in virtual manufacturing networks
Krenczyk, D.; Skolud, B.; Olender, M.
2017-08-01
The increasing requirements and competition in the global market are challenges for the companies profitability in production and supply chain management. This situation became the basis for construction of virtual organizations, which are created in response to temporary needs. The problem of the production flow planning in virtual manufacturing networks is considered. In the paper the algorithm of the production route selection from the set of admissible routes, which meets the technology and resource requirements and in the context of the criterion of minimum cost is proposed.
Eco-sustainable routing in optical networks
DEFF Research Database (Denmark)
Ricciardi, Sergio; Wang, Jiayuan; Palmieri, Francesco;
2013-01-01
infrastructures are now widely recognized to play a fundamental role in the emission of green-house gases (GHG) in the at- mosphere, signicantly aecting the environmental sustainability of new evolutions in network architectures as well as technological developments in communication devices. In this paper......It is quite easy to foresee that in the next years, the future generation ultra-high speed network infrastructures and equipments will be no longer constrained only by their pure transport capacity, but also by their energy consumption costs and environmental eects. In particular, large network......, a novel eco-sustainable Routing and Wavelength Assignment (RWA) algorithm, based on shortest-path routing with an adaptive link weighting function relying on an extension of the OSPF-TE protocol to convey carbon footprint information, has been proposed to decrease the network ecological impact while...
Routing Optimization of AVB Streams in TSN Networks
DEFF Research Database (Denmark)
Laursen, Sune Mølgaard; Pop, Paul; Steiner, Wilfried
2016-01-01
of the network as well as the routes and schedules of the TT streams. We are interested to determine the routing of the AVB streams such that all frames are schedulable and their worst-case end-to-end delay is minimized. We have proposed a search-space reduction technique and a Greedy Randomized Adaptive Search...... Procedure (GRASP)-based heuristic for this routing optimization problem. The proposed approaches has been evaluated using several test cases....
Optimal paths planning in dynamic transportation networks with random link travel times
Institute of Scientific and Technical Information of China (English)
孙世超; 段征宇; 杨东援
2014-01-01
A theoretical study was conducted on finding optimal paths in transportation networks where link travel times were stochastic and time-dependent (STD). The methodology of relative robust optimization was applied as measures for comparing time-varying, random path travel times for a priori optimization. In accordance with the situation in real world, a stochastic consistent condition was provided for the STD networks and under this condition, a mathematical proof was given that the STD robust optimal path problem can be simplified into a minimum problem in specific time-dependent networks. A label setting algorithm was designed and tested to find travelers’ robust optimal path in a sampled STD network with computation complexity of O(n2+n·m). The validity of the robust approach and the designed algorithm were confirmed in the computational tests. Compared with conventional probability approach, the proposed approach is simple and efficient, and also has a good application prospect in navigation system.
An Application of Intuitionistic Fuzzy in Routing Networks
Directory of Open Access Journals (Sweden)
Ashit Kumar Dutta
2012-06-01
Full Text Available Routing is an important functional aspect of networks to transport packets from source to destination. A router sets up optimized paths among the different nodes in the network. In this paper the authors proposed a new type of routing algorithm which includes exchange of routing information for small amount of time and then halts for few hours but this information is used by each router to make its own routing decisions based on intuitionistic fuzzy logic during these hours.
An Optical Multicast Routing with Minimal Network Coding Operations in WDM Networks
Directory of Open Access Journals (Sweden)
Huanlin Liu
2014-01-01
Full Text Available Network coding can improve the optical multicast routing performance in terms of network throughput, bandwidth utilization, and traffic load balance. But network coding needs high encoding operations costs in all-optical WDM networks due to shortage of optical RAM. In the paper, the network coding operation is defined to evaluate the number of network coding operation cost in the paper. An optical multicast routing algorithm based on minimal number of network coding operations is proposed to improve the multicast capacity. Two heuristic criteria are designed to establish the multicast routing with low network coding cost and high multicast capacity. One is to select one path from the former K shortest paths with the least probability of dropping the multicast maximal capacity. The other is to select the path with lowest potential coding operations with the highest link shared degree among the multiple wavelength disjoint paths cluster from source to each destination. Comparing with the other multicast routing based on network coding, simulation results show that the proposed multicast routing algorithm can effectively reduce the times of network coding operations, can improve the probability of reaching multicast maximal capacity, and can keep the less multicast routing link cost for optical WDM networks.
ORDERED TREE-BASED ROUTING ALGORITHM FOR POWER LINE COMMUNICATION NETWORK%基于有序树的电力线网络路由算法
Institute of Scientific and Technical Information of China (English)
何华冰; 姚婷婷; 李云飞; 贾俊铖
2016-01-01
Power line communication (PLC)is getting more and more attentions because it transmits data only relying on existing widespread power line facilities without additional wiring cost.However,current power line network still has the problems of low routing efficiency and high communication delay.To overcome these problems,we propose a tree routing algorithm,short for PLC-TR,according to the characteristics of tree topology of power line network.Specifically,PLC-TR first organises the power line networks into an ordered tree,and then selects the routes by comparing their addresses,this minimises the network overhead caused by routing maintenance.It is shown through simulation that compared with the shortest path routing (SPR)which is traditionally one of the optimal algorithms,under the same disturbance the PLC-TR has lower average packet transmission delay and higher packet delivery rate.%电力线通信（PLC）依靠现有的分布广泛的电力线路设施进行数据传输不需要额外布线开销，越来越受到人们的关注。但是，目前电力线网络路由效率不高，通信延迟较大。为解决以上问题，根据电力线网络的树型拓扑结构的特点，提出一种树路由算法（PLC-TR）。算法将电力线网络组织成一棵有序树，并通过地址比较进行路由选择，最大限度降低了因路由维护产生的网络开销。通过仿真表明，和传统上性能优异的最短路径算法（SPR）相比，在同等干扰情况下，PLC-TR 具有较低的数据包平均传输时延和较高的数据包交付率。
Institute of Scientific and Technical Information of China (English)
高强; 陈欣; 汪振华
2011-01-01
航空安全是空中交通运输系统正常运行的基础,快度、高效的处理航空安全事故对恢复空中交通系统的正常运行具有重要意义.文章从机场航空安全角度出发,通过分析机场飞行区地面网络结构图,创建了节点、弧段关系数据库以描述机场飞行区的网络拓扑结构,运用Dijkstra算法实现了快速最短路径搜索.在此基础上利用地理信息系统(GIS)二次开发工具MapX组件,以国内某机场为例,在Visusal Basic环境下实现了机场飞行区应急救援信息管理系统,为机场应急救援管理决策的可视化、便捷化提供了支持.同时拓展了MapX开发应用型地理信息系统的空间分析能力.%Aviation safety is the base for the operation of an efficient air transportation system. Quick deployment of emergency rescue has an important meaning to reinstall air transportation in a timely manner. In this paper, through the analysis of airport surface topology, a node-arc relational database is developed and the network topology of airport airside is abstracted. The Dijkstra algorithm is employed to search the shortest path between any nodes. The above components are integrated into the MapXf which is a GIS re-developing tool, within the Visual Basic environment, in order to establish an Emergency Rescue Information Management System for a large domestic airport. The developed system can provide visual and various decision-making support for airport emergency rescue events. This study also expands the spatial analysis capability of MapX in the applied GIS systems.
Traffic optimization in transport networks based on local routing
Scellato, S.; Fortuna, L.; Frasca, M.; Gómez-Gardeñes, J.; Latora, V.
2010-01-01
Congestion in transport networks is a topic of theoretical interest and practical importance. In this paper we study the flow of vehicles in urban street networks. In particular, we use a cellular automata model on a complex network to simulate the motion of vehicles along streets, coupled with a congestion-aware routing at street crossings. Such routing makes use of the knowledge of agents about traffic in nearby roads and allows the vehicles to dynamically update the routes towards their destinations. By implementing the model in real urban street patterns of various cities, we show that it is possible to achieve a global traffic optimization based on local agent decisions.
A Cross-Layer Delay-Aware Node Disjoint Multipath Routing Algorithm for Mobile Ad Hoc Networks
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Mahadev A. Gawas
2014-09-01
Full Text Available Mobile Ad Hoc Networks (MANETS require reliable routing and Quality of Service(QoS mechanism to support diverse applications with varying and stringent requirements for delay, jitter, bandwidth, packets loss. Routing protocols such as AODV, AOMDV, DSR and OLSR use shortest path with minimum hop count as the main metric for path selection, hence are not suitable for delay sensitive real time applications. To support such applications delay constrained routing protocols are employed. These Protocols makes path selection between source and destination based on the delay over the discovered links during routing discovery and routing table calculations. We propose a variation of a node-disjoint Multipath QoS Routing protocol called Cross Layer Delay aware Node Disjoint Multipath AODV (CLDMAODV based on delay constraint. It employs cross-layer communications between MAC and routing layers to achieve link and channel-awareness. It regularly updates the path status in terms of lowest delay incurred at each intermediate node. Performance of the proposed protocol is compared with single path AODV and NDMR protocols. Proposed CLDM-AODV is superior in terms of better packet delivery and reduced overhead between intermediate nodes.
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Jing Chen
2015-06-01
Full Text Available This study takes the concept of food logistics distribution as the breakthrough point, by means of the aim of optimization of food logistics distribution routes and analysis of the optimization model of food logistics route, as well as the interpretation of the genetic algorithm, it discusses the optimization of food logistics distribution route based on genetic and cluster scheme algorithm.
A dynamic routing strategy with limited buffer on scale-free network
Wang, Yufei; Liu, Feng
2016-04-01
In this paper, we propose an integrated routing strategy based on global static topology information and local dynamic data packet queue lengths to improve the transmission efficiency of scale-free networks. The proposed routing strategy is a combination of a global static routing strategy (based on the shortest path algorithm) and local dynamic queue length management, in which, instead of using an infinite buffer, the queue length of each node i in the proposed routing strategy is limited by a critical queue length Qic. When the network traffic is lower and the queue length of each node i is shorter than its critical queue length Qic, it forwards packets according to the global routing table. With increasing network traffic, when the buffers of the nodes with higher degree are full, they do not receive packets due to their limited buffers and the packets have to be delivered to the nodes with lower degree. The global static routing strategy can shorten the transmission time that it takes a packet to reach its destination, and the local limited queue length can balance the network traffic. The optimal critical queue lengths of nodes have been analysed. Simulation results show that the proposed routing strategy can get better performance than that of the global static strategy based on topology, and almost the same performance as that of the global dynamic routing strategy with less complexity.
From the Physics of Interacting Polymers to Optimizing Routes on the London Underground
Yeung, Chi Ho; Wong, K Y Michael
2013-01-01
Optimizing paths on networks is crucial for many applications, from subway traffic to Internet communication. As global path optimization that takes account of all path-choices simultaneously is computationally hard, most existing routing algorithms optimize paths individually, thus providing sub-optimal solutions. We employ the physics of interacting polymers and disordered systems to analyze macroscopic properties of generic path-optimization problems and derive a simple, principled, generic and distributed routing algorithm capable of considering simultaneously all individual path choices. We demonstrate the efficacy of the new algorithm by applying it to: (i) random graphs resembling Internet overlay networks; (ii) travel on the London underground network based on Oyster-card data; and (iii) the global airport network. Analytically derived macroscopic properties give rise to insightful new routing phenomena, including phase transitions and scaling laws, which facilitate better understanding of the appropr...
Prograph Based Analysis of Single Source Shortest Path Problem with Few Distinct Positive Lengths
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B. Bhowmik
2011-08-01
Full Text Available In this paper we propose an experimental study model S3P2 of a fast fully dynamic programming algorithm design technique in finite directed graphs with few distinct nonnegative real edge weights. The Bellman-Ford’s approach for shortest path problems has come out in various implementations. In this paper the approach once again is re-investigated with adjacency matrix selection in associate least running time. The model tests proposed algorithm against arbitrarily but positive valued weighted digraphs introducing notion of Prograph that speeds up finding the shortest path over previous implementations. Our experiments have established abstract results with the intention that the proposed algorithm can consistently dominate other existing algorithms for Single Source Shortest Path Problems. A comparison study is also shown among Dijkstra’s algorithm, Bellman-Ford algorithm, and our algorithm.
An Efficient Algorithm for Congestion Control in Highly Loaded DiffServ/MPLS Networks
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Srecko Krile
2009-06-01
Full Text Available The optimal QoS path provisioning of coexisted and aggregated traffic in networks is still demanding problem. All traffic flows in a domain are distributed among LSPs (Label Switching Path related to N service classes, but the congestion problem of concurrent flows can appear. As we know the IGP (Interior Getaway Protocol uses simple on-line routing algorithms (e.g. OSPFS, IS-IS based on shortest path methodology. In QoS end-to-end provisioning where some links may be reserved for certain traffic classes (for particular set of users it becomes insufficient technique. On other hand, constraint based explicit routing (CR based on IGP metric ensures traffic engineering (TE capabilities. The algorithm proposed in this paper may find a longer but lightly loaded path, better than the heavily loaded shortest path. LSP can be pre-computed much earlier, possibly during SLA (Service Level Agreement negotiation process. As we need firm correlation with bandwidth management and traffic engineering (TE the initial (pro-active routing can be pre-computed in the context of all priority traffic flows (former contracted SLAs traversing the network simultaneously. It could be a very good solution for congestion avoidance and for better load-balancing purpose where links are running close to capacity. Also, such technique could be useful in inter-domain end-to-end provisioning, where bandwidth reservation has to be negotiated with neighbor ASes (Autonomous System. To be acceptable for real applications such complicated routing algorithm can be significantly improved. Algorithm was tested on the network of M core routers on the path (between edge routers and results are given for N=3 service classes. Further improvements through heuristic approach are made and results are discussed.
Energy Optimization for Wireless Sensor Networks using a Novel Dynamic Multicast Routing Protocol
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S. Sundar Raj
2014-07-01
Full Text Available Minimization of energy consumption has always been the predominant factor deciding the acceptability of a routing protocol for wireless ad-hoc networks. In this study we have proposed a novel efficient multicast routing protocols in wireless mobile ad hoc networks is proposed. Due to the high mobility of nodes and highly dynamic topology, performing efficient and robust multicast in a Mobile Ad hoc Network (MANET is a challenging task. Most of existing multicast protocols in MANETs discover the routing path by flooding message over the whole network, which result in considerable cost for routing discovery and maintenance. Moreover, the reliability of the discovered path cannot be guaranteed, since the stabilities of nodes along such path are unpredictable. Here an attempt is made to devise an algorithm combining the features of both energy efficient and low latency algorithms. The new algorithm is intended to do well in real-world scenarios where the energy capacities of the nodes are not uniform. It employs a mobility prediction based election process to construct a reliable backbone structure performing packet transmission, message flooding, routing discovery and maintenance. Several virtual architectures are used in the protocol without need of maintaining state information for more robust and scalable membership management and packet forwarding in the presence of high network dynamics due to unstable wireless channels and node movements.
An Optimal Path Computation Architecture for the Cloud-Network on Software-Defined Networking
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Hyunhun Cho
2015-05-01
Full Text Available Legacy networks do not open the precise information of the network domain because of scalability, management and commercial reasons, and it is very hard to compute an optimal path to the destination. According to today’s ICT environment change, in order to meet the new network requirements, the concept of software-defined networking (SDN has been developed as a technological alternative to overcome the limitations of the legacy network structure and to introduce innovative concepts. The purpose of this paper is to propose the application that calculates the optimal paths for general data transmission and real-time audio/video transmission, which consist of the major services of the National Research & Education Network (NREN in the SDN environment. The proposed SDN routing computation (SRC application is designed and applied in a multi-domain network for the efficient use of resources, selection of the optimal path between the multi-domains and optimal establishment of end-to-end connections.
Smith, K; Abasolo, D.; Escudero, J.
2016-01-01
The Cluster-Span Threshold (CST) is a recently introduced unbiased threshold for functional connectivity networks. This binarisation technique offers a natural trade-off of sparsity and density of information by balancing the ratio of closed to open triples in the network topology. Here we present findings comparing it with the Union of Shortest Paths (USP), another recently proposed objective method. We analyse standard network metrics of binarised networks for sensitivity to clinical Alzhei...
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Chao Guo
2017-01-01
Full Text Available An optimal routing scheme in space information networks was presented to balance network loads for heterogeneous users. According to the competition among the nodes, the model was built based on queuing game theory. The virtual routing platform was in charge of resources allocation and route selection. It got user’s gain to decide which node the user joined in. Owning to the existing of heterogeneous users, an optimal admission fee needed to be obtained to avoid congestion. In our model, firstly, the whole welfare of the system was formulated. Then the optimal admission fee was calculated through maximizing the whole welfare. Meanwhile, the average maximum queue length was generated to set the buffer space of the node. At last, a routing factor was introduced into the route algorithm in order that the optimal routing could be selected by heterogeneous users. As a result, the system welfare reaches the maximum.
Optimal Path Identification Using ANT Colony Optimisation in Wireless Sensor Network
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Aniket. A. Gurav
2013-05-01
Full Text Available Wireless Sensor Network WSN is tightly constrained for energy, computational power and memory. All applications of WSN require to forward data from remote sensor node SN to base station BS. The path length and numbers of nodes in path by which data is forwarded affect the basic performance of WSN. In this paper we present bio-Inspired Ant Colony Optimisation ACO algorithm for Optimal path Identification OPI for p acket transmission to communicate between SN to BS. Our modified algorithm OPI using ACO cons iders the path length and the number of hops in path for data packet transmission, with an aim to reduce communication overheads .
The information transmission in community networks
Zhu, Zhi-Qiang; Liu, Chuan-Jian; Wu, Jian-Liang; Liu, Bin
2013-09-01
The community structure has been empirically found in many real networks. This paper proposes an efficient Double Shortest Path routing strategy trying to avoid the modules of traffic congestion, which means that we adopt the shortest routing strategy both in the inter-modules and in the intra-module. Simulations show that this routing algorithm is superior to the traditional shortest path routing protocol with appropriate selection of the tunable parameters. In addition, this algorithm can also be improved by integrating it with several alternative routing strategies.
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Jean Chamberlain Chedjou
2015-01-01
Full Text Available This paper develops a flexible analytical concept for robust shortest path detection in dynamically reconfigurable graphs. The concept is expressed by a mathematical model representing the shortest path problem solver. The proposed mathematical model is characterized by three fundamental parameters expressing (a the graph topology (through the “incidence matrix”, (b the edge weights (with dynamic external weights’ setting capability, and (c the dynamic reconfigurability through external input(s of the source-destination nodes pair. In order to demonstrate the universality of the developed concept, a general algorithm is proposed to determine the three fundamental parameters (of the mathematical model developed for all types of graphs regardless of their topology, magnitude, and size. It is demonstrated that the main advantage of the developed concept is that arc costs, the origin-destination pair setting, and the graph topology are dynamically provided by external commands, which are inputs of the shortest path solver model. This enables high flexibility and full reconfigurability of the developed concept, without any retraining need. To validate the concept developed, benchmarking is performed leading to a comparison of its performance with the performances of two well-known concepts based on neural networks.
Dynamic route guidance algorithm based algorithm based on artificial immune system
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
To improve the performance of the K-shortest paths search in intelligent traffic guidance systems,this paper proposes an optimal search algorithm based on the intelligent optimization search theory and the memphor mechanism of vertebrate immune systems.This algorithm,applied to the urban traffic network model established by the node-expanding method,can expediently realize K-shortest paths search in the urban traffic guidance systems.Because of the immune memory and global parallel search ability from artificial immune systems,K shortest paths can be found without any repeat,which indicates evidently the superiority of the algorithm to the conventional ones.Not only does it perform a better parallelism,the algorithm also prevents premature phenomenon that often occurs in genetic algorithms.Thus,it is especially suitable for real-time requirement of the traffic guidance system and other engineering optimal applications.A case study verifies the efficiency and the practicability of the algorithm aforementioned.
Institute of Scientific and Technical Information of China (English)
宋渊; 姚向华; 张新曼
2012-01-01
应用于无线Ad Hoc网络中的机会路由,结点转发候选集的选取通常是基于最短路径期望传输次数,没有充分考虑无线网络结点进行数据转发的广播特性.以多路径期望传输次数为路由量度,提出一种最优转发候选集算法MCET.实现对无线网络中除了目的结点以外的所有结点选取考虑多路径转发期望值的转发候选集,并在按照结点选取的顺序依次优先排列优先级.仿真结果表明,比较于传统的基于最短路径期望传输次数的机会路由,应用了最优转发候选集算法的机会路由明显减少了数据的平均传输次数,增加了数据报文的成功传输率.%The opportunistic routing for wireless Ad Hoc networks usually selects node forwarding candidate set based on shortest path ETX (expected transmission count) but regardless the broadcasting property of wireless networks nodes when forwarding data. In this paper, we take multipath ETX as the routing metric, and propose an optimal forwarding candidates set algorithm MCET (multipath-considered expected transmission). It realises the selection of forwarding candidate set with multipath forwarding expected value consideration for all nodes in wireless networks other than the destination, and then prioritise them in turn according to the order the nodes selected. Simulation results indicate that compared with traditional opportunistic routing based on shortest path ETX, the opportunistic routing applied the optimal forwarding candidate set algorithm has noticeably reduced the average number of data transmission, and increased the successful delivering rate of data packet.
Tien, Nguyen Xuan; Kim, Semog; Rhee, Jong Myung; Park, Sang Yoon
2017-07-25
Fault tolerance has long been a major concern for sensor communications in fault-tolerant cyber physical systems (CPSs). Network failure problems often occur in wireless sensor networks (WSNs) due to various factors such as the insufficient power of sensor nodes, the dislocation of sensor nodes, the unstable state of wireless links, and unpredictable environmental interference. Fault tolerance is thus one of the key requirements for data communications in WSN applications. This paper proposes a novel path redundancy-based algorithm, called dual separate paths (DSP), that provides fault-tolerant communication with the improvement of the network traffic performance for WSN applications, such as fault-tolerant CPSs. The proposed DSP algorithm establishes two separate paths between a source and a destination in a network based on the network topology information. These paths are node-disjoint paths and have optimal path distances. Unicast frames are delivered from the source to the destination in the network through the dual paths, providing fault-tolerant communication and reducing redundant unicast traffic for the network. The DSP algorithm can be applied to wired and wireless networks, such as WSNs, to provide seamless fault-tolerant communication for mission-critical and life-critical applications such as fault-tolerant CPSs. The analyzed and simulated results show that the DSP-based approach not only provides fault-tolerant communication, but also improves network traffic performance. For the case study in this paper, when the DSP algorithm was applied to high-availability seamless redundancy (HSR) networks, the proposed DSP-based approach reduced the network traffic by 80% to 88% compared with the standard HSR protocol, thus improving network traffic performance.
An Efficient Method For Multichannel Wireless Mesh Networks With Pulse Coupled Neural Network
Sobana, S
2012-01-01
Multi cast communication is a key technology for wireless mesh networks. Multicast provides efficient data distribution among a group of nodes, Generally sensor networks and MANETs uses multicast algorithms which are designed to be energy efficient and to achieve optimal route discovery among mobile nodes whereas wireless mesh networks needs to maximize throughput. Here we propose two multicast algorithms: The Level Channel Assignment (LCA) algorithm and the Multi-Channel Multicast (MCM) algorithm to improve the throughput for multichannel sand multi interface mesh networks. The algorithm builds efficient multicast trees by minimizing the number of relay nodes and total hop count distance of the trees. Shortest path computation is a classical combinatorial optimization problem. Neural networks have been used for processing path optimization problem. Pulse Coupled Neural Networks (PCNNS) suffer from high computational cast for very long paths we propose a new PCNN modal called dual source PCNN (DSPCNN) which c...
Kröger, Martin
2005-06-01
program has been tested: UNIX, Linux Program language used: USANSI Fortran 77 and Fortran 90 Memory required to execute with typical data: 1 MByte No. of lines in distributed program, including test data, etc.: 10 660 No. of bytes in distributed program, including test data, etc.: 119 551 Distribution formet:tar.gz Nature of physical problem: The problem is to obtain primitive paths substantiating a shortest multiple disconnected path (SP) for a given polymer configuration (chains of particles, with or without additional single particles as obstacles for the 2D case). Primitive paths are here defined as in [M. Rubinstein, E. Helfand, J. Chem. Phys. 82 (1985) 2477; R. Everaers, S.K. Sukumaran, G.S. Grest, C. Svaneborg, A. Sivasubramanian, K. Kremer, Science 303 (2004) 823] as the shortest line (path) respecting 'topological' constraints (from neighboring polymers or point obstacles) between ends of polymers. There is a unique solution for the 2D case. For the 3D case it is unique if we construct a primitive path of a single chain embedded within fixed line obstacles [J.S.B. Mitchell, Geometric shortest paths and network optimization, in: J.-R. Sack, J. Urrutia (Eds.), Handbook of Computational Geometry, Elsevier, Amsterdam, 2000, pp. 633-701]. For a large 3D configuration made of several chains, short is meant to be the Euclidean shortest multiple disconnected path (SP) where primitive paths are constructed for all chains simultaneously. While the latter problem, in general, does not possess a unique solution, the algorithm must return a locally optimal solution, robust against minor displacements of the disconnected path and chain re-labeling. The problem is solved if the number of kinks (or entanglements Z), explicitly deduced from the SP, is quite insensitive to the exact conformation of the SP which allows to estimate Z with a small error. Efficient method of solution: Primitive paths are constructed from the given polymer configuration (a non-shortest multiple
Oki, Eiji
2012-01-01
Explaining how to apply to mathematical programming to network design and control, Linear Programming and Algorithms for Communication Networks: A Practical Guide to Network Design, Control, and Management fills the gap between mathematical programming theory and its implementation in communication networks. From the basics all the way through to more advanced concepts, its comprehensive coverage provides readers with a solid foundation in mathematical programming for communication networks. Addressing optimization problems for communication networks, including the shortest path problem, max f
DESIGN OF ANTRO ROUTING PROTOCOL FOR UNDERWATER WIRELESS SENSOR NETWORK
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R. Srinithi
2015-10-01
Full Text Available Existing routing algorithms are not effective in supporting the dynamic characteristics of underwater wireless sensor networks (UWSNs and cannot ensure sufficient quality of service in UWSN applications. This project proposes a probabilistic technique for solving computational problems which can be reduced to finding better paths through graphs. . This algorithm is a member of an ant colony algorithms family, in swarm intelligence methods, the algorithm was aiming to search for an optimal path in a graph.
Genetic algorithm for flood detection and evacuation route planning
Gomes, Rahul; Straub, Jeremy
2017-05-01
A genetic-type algorithm is presented that uses satellite geospatial data to determine the most probable path to safety for individuals in a disaster area, where a traditional routing system cannot be used. The algorithm uses geological features and disaster information to determine the shortest safe path. It predicts how a flood can change a landform over time and uses this data to predict alternate routes. It also predicts safe routes in rural locations where GPS/map-based routing data is unavailable or inaccurate. Reflectance and a supervised classification algorithm are used and the output is compared with RFPI and PCR-GLOBWB data.
Kuperstein, Inna; Grieco, Luca; Cohen, David P A; Thieffry, Denis; Zinovyev, Andrei; Barillot, Emmanuel
2015-03-01
Several decades of molecular biology research have delivered a wealth of detailed descriptions of molecular interactions in normal and tumour cells. This knowledge has been functionally organised and assembled into dedicated biological pathway resources that serve as an invaluable tool, not only for structuring the information about molecular interactions but also for making it available for biological, clinical and computational studies. With the advent of high-throughput molecular profiling of tumours, close to complete molecular catalogues of mutations, gene expression and epigenetic modifications are available and require adequate interpretation. Taking into account the information about biological signalling machinery in cells may help to better interpret molecular profiles of tumours. Making sense out of these descriptions requires biological pathway resources for functional interpretation of the data. In this review, we describe the available biological pathway resources, their characteristics in terms of construction mode, focus, aims and paradigms of biological knowledge representation. We present a new resource that is focused on cancer-related signalling, the Atlas of Cancer Signalling Networks. We briefly discuss current approaches for data integration, visualisation and analysis, using biological networks, such as pathway scoring, guilt-by-association and network propagation. Finally, we illustrate with several examples the added value of data interpretation in the context of biological networks and demonstrate that it may help in analysis of high-throughput data like mutation, gene expression or small interfering RNA screening and can guide in patients stratification. Finally, we discuss perspectives for improving precision medicine using biological network resources and tools. Taking into account the information about biological signalling machinery in cells may help to better interpret molecular patterns of tumours and enable to put precision
Optimization of wireless sensor networks based on chicken swarm optimization algorithm
Wang, Qingxi; Zhu, Lihua
2017-05-01
In order to reduce the energy consumption of wireless sensor network and improve the survival time of network, the clustering routing protocol of wireless sensor networks based on chicken swarm optimization algorithm was proposed. On the basis of LEACH agreement, it was improved and perfected that the points on the cluster and the selection of cluster head using the chicken group optimization algorithm, and update the location of chicken which fall into the local optimum by Levy flight, enhance population diversity, ensure the global search capability of the algorithm. The new protocol avoided the die of partial node of intensive using by making balanced use of the network nodes, improved the survival time of wireless sensor network. The simulation experiments proved that the protocol is better than LEACH protocol on energy consumption, also is better than that of clustering routing protocol based on particle swarm optimization algorithm.
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Huseyin Ceylan
2013-01-01
Full Text Available This study proposes a traffic congestion minimization model in which the traffic signal setting optimization is performed through a combined simulation-optimization model. In this model, the TRANSYT traffic simulation software is combined with Differential Evolution (DE optimization algorithm, which is based on the natural selection paradigm. In this context, the EQuilibrium Network Design (EQND problem is formulated as a bilevel programming problem in which the upper level is the minimization of the total network performance index. In the lower level, the traffic assignment problem, which represents the route choice behavior of the road users, is solved using the Path Flow Estimator (PFE as a stochastic user equilibrium assessment. The solution of the bilevel EQND problem is carried out by the proposed Differential Evolution and TRANSYT with PFE, the so-called DETRANSPFE model, on a well-known signal controlled test network. Performance of the proposed model is compared to that of two previous works where the EQND problem has been solved by Genetic-Algorithms- (GAs- and Harmony-Search- (HS- based models. Results show that the DETRANSPFE model outperforms the GA- and HS-based models in terms of the network performance index and the computational time required.
An Optimal Lifetime Utility Routing for 5G and Energy-Harvesting Wireless Networks
Institute of Scientific and Technical Information of China (English)
Gina Martinez; Shufang Li; Chi Zhou
2015-01-01
Harvesting energy from environmental sources such as solar and wind can mitigate or solve the limited⁃energy problem in wireless sensor networks. In this paper, we propose an energy⁃harvest⁃aware route⁃selection method that incorporates harvest availability properties and energy storage capacity limits into the routing decisions. The harvest⁃aware routing problem is formulated as a lin⁃ear program with a utility⁃based objective function that balances the two conflicting routing objectives of maximum total and maxi⁃mum minimum residual network energy. The simulation results show that doing so achieves a longer network lifetime, defined as the time⁃to⁃first⁃node⁃death in the network. Additionally, most existing energy⁃harvesting routing algorithms route each traffic flow independently from each other. The LP formulation allows for a joint optimization of multiple traffic flows. Better residual energy statistics are also achieved by such joint consideration compared to independent optimization of each commodity.
A Reliability-based Framework for Multi-path Routing Analysis in Mobile Ad-Hoc Networks
Caleffi, Marcello; Paura, Luigi
2008-01-01
Unlike traditional routing procedures that, at the best, single out a unique route, multi-path routing protocols discover proactively several alternative routes. It has been recognized that multi-path routing can be more efficient than traditional one mainly for mobile ad hoc networks, where route failure events are frequent. Most studies in the area of multi-path routing focus on heuristic methods, and the performances of these strategies are commonly evaluated by numerical simulations. The need of a theoretical analysis motivates such a paper, which proposes to resort to the terminal-pair routing reliability as performance metric. This metric allows one to assess the performance gain due to the availability of route diversity. By resorting to graph theory, we propose an analytical framework to evaluate the tolerance of multi-path route discovery processes against route failures for mobile ad hoc networks. Moreover, we derive a useful bound to easily estimate the performance improvements achieved by multi-pa...
Effective local dynamic routing strategy for air route networks
Institute of Scientific and Technical Information of China (English)
Wu Wenjun; Zhao Lingxi
2015-01-01
With the rapid development of air transportation, network service ability has attracted a lot of attention in academe. Aiming to improve the throughput of the air route network (ARN), we propose an effective local dynamic routing strategy in this paper. Several factors, such as the rout-ing distance, the geographical distance and the real-time local traffic, are taken into consideration. When the ARN is in the normal free-flow state, the proposed strategy can recover the shortest path routing (SPR) strategy. When the ARN undergoes congestion, the proposed strategy changes the paths of flights based on the real-time local traffic information. The throughput of the Chinese air route network (CARN) is evaluated. Results confirm that the proposed strategy can significantly improve the throughput of CARN. Meanwhile, the increase in the average flying distance and time is tiny. Results also indicate the importance of the distance related factors in a routing strategy designed for the ARN.
Autoconfiguration Algorithm for a Multiple Interfaces Adhoc Network Running OLSR Routing Protocol
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Saadi Boudjit
2013-02-01
Full Text Available Network configuration is the assignment of network parameters necessary for a device to integrate the network, examples being: an IP address, netmask, the IP address of the gateway, etc ... In the case of Mobile Ad hoc NETworks (MANETs, the connectivity of nodes is highly dynamic and a central administration or configuration by the user is very difficult. This paper presents an autoconfiguration solution for ad hoc networks running the widely implemented version of OLSR routing protocol, the 2003 RFC 3626 [1]. This solution is based on an efficient Duplicate Address Detection (DAD algorithm, which takes advantage of the genuine optimization of the OLSR routing protocol. The proposed autoconfiguration algorithm is proved to operate correctly in a multiple interfaces OLSR network.
Iyer, Sridhar
2016-12-01
The ever-increasing global Internet traffic will inevitably lead to a serious upgrade of the current optical networks' capacity. The legacy infrastructure can be enhanced not only by increasing the capacity but also by adopting advance modulation formats, having increased spectral efficiency at higher data rate. In a transparent mixed-line-rate (MLR) optical network, different line rates, on different wavelengths, can coexist on the same fiber. Migration to data rates higher than 10 Gbps requires the implementation of phase modulation schemes. However, the co-existing on-off keying (OOK) channels cause critical physical layer impairments (PLIs) to the phase modulated channels, mainly due to cross-phase modulation (XPM), which in turn limits the network's performance. In order to mitigate this effect, a more sophisticated PLI-Routing and Wavelength Assignment (PLI-RWA) scheme needs to be adopted. In this paper, we investigate the critical impairment for each data rate and the way it affects the quality of transmission (QoT). In view of the aforementioned, we present a novel dynamic PLI-RWA algorithm for MLR optical networks. The proposed algorithm is compared through simulations with the shortest path and minimum hop routing schemes. The simulation results show that performance of the proposed algorithm is better than the existing schemes.
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Ning Zhang
2014-01-01
Full Text Available The recently emerging Influenza A/H7N9 virus is reported to be able to infect humans and cause mortality. However, viral and host factors associated with the infection are poorly understood. It is suggested by the “guilt by association” rule that interacting proteins share the same or similar functions and hence may be involved in the same pathway. In this study, we developed a computational method to identify Influenza A/H7N9 virus infection-related human genes based on this rule from the shortest paths in a virus-human protein interaction network. Finally, we screened out the most significant 20 human genes, which could be the potential infection related genes, providing guidelines for further experimental validation. Analysis of the 20 genes showed that they were enriched in protein binding, saccharide or polysaccharide metabolism related pathways and oxidative phosphorylation pathways. We also compared the results with those from human rhinovirus (HRV and respiratory syncytial virus (RSV by the same method. It was indicated that saccharide or polysaccharide metabolism related pathways might be especially associated with the H7N9 infection. These results could shed some light on the understanding of the virus infection mechanism, providing basis for future experimental biology studies and for the development of effective strategies for H7N9 clinical therapies.
Optimal path for a quantum teleportation protocol in entangled networks
di Franco, C.; Ballester, D.
2012-01-01
Bellman's optimality principle has been of enormous importance in the development of whole branches of applied mathematics, computer science, optimal control theory, economics, decision making, and classical physics. Examples are numerous: dynamic programming, Markov chains, stochastic dynamics, calculus of variations, and the brachistochrone problem. Here we show that Bellman's optimality principle is violated in a teleportation problem on a quantum network. This implies that finding the optimal fidelity route for teleporting a quantum state between two distant nodes on a quantum network with bipartite entanglement will be a tough problem and will require further investigation.
Robust multi-path routing for dynamic topology in wireless sensor networks
Institute of Scientific and Technical Information of China (English)
HUANG Ping; TIAN Hui; ZHANG Ming; ZHANG Ping
2007-01-01
Wireless sensor networks are being widely researched and are expected to be used in several scenarios. On the leading edge of treads, on-demand, high-reliability, and low-latency routing protocol is desitable for indoor environment applications.This article proposes a routing scheme called robust multi-path routing that establishes and uses multiple node-disjoint routes.Providing multiple routes helps to reduce the route recovery process and control the message overhead. The performance comparison of this protocol with dynamic source routing (DSR) by OPNET simulations shows that this protocol is able to achieve a remarkable improvement in the packet delivery ratio and average end-to-end delay.
Polynomial time algorithm for hop-constrained QoS routing
Verma, Shekhar; Saxena, Anil K.
2003-08-01
The basis of a QoS-based routing algorithm is a dynamic network dependent cost function that is used to find the optimal or at least a feasible route across the network. However, all QoS-based routing algorithms suffer from a major drawback. The cost function at the core of the algorithms identifies segments of the network where resources are ample and exploits them to the benefit of connections that would otherwise cross a congested portion of the network. Thus, the algorithms consume more resources than Minimum Hop routing would do when the network traffic is non-stationary and heavy. QoS-based routing, thus, wastes resources and performs poorly compared with Minimum Hop routing in the event of congestion. The crux of the discussion is that whatever is gained at low or medium network loads, is offset at high network loads. What is required is a resilient algorithm that either allows the migration of a QoS-based routing algorithm to a Minimum Hop algorithm at high loads or an algorithm that merges Minimum Hop and QoS characteristics. The study opts for the latter approach and proposes and exhibits a hop constrained QoS routing algorithm that outperforms traditional QoS routing algorithms during simulation. This routing technique is based on an approximation algorithm that solves the hop constrained routing problem. The algorithm is derived from a dynamic programming FPAS scheme and finds the shortest walk for a single source destination pair in a graph with restricted number of hops when all the edge costs are non-negative. Simulated results demonstrate that routing technique based on the algorithm is robust to changes in the traffic pattern and consistently outperforms other QoS based routing techniques under heavy load conditions.
External Data Structures for Shortest Path Queries on Planar Digraphs
DEFF Research Database (Denmark)
Arge, Lars; Toma, Laura
2005-01-01
In this paper we present space-query trade-offs for external memory data structures that answer shortest path queries on planar directed graphs. For any S = Ω(N 1 + ε) and S = O(N2/B), our main result is a family of structures that use S space and answer queries in O(N2/ S B) I/Os, thus obtaining...... optimal space-query product O(N2/B). An S space structure can be constructed in O(√S · sort(N)) I/Os, where sort(N) is the number of I/Os needed to sort N elements, B is the disk block size, and N is the size of the graph....
An improved global dynamic routing strategy for scale-free network with tunable clustering
Sun, Lina; Huang, Ning; Zhang, Yue; Bai, Yannan
2016-08-01
An efficient routing strategy can deliver packets quickly to improve the network capacity. Node congestion and transmission path length are inevitable real-time factors for a good routing strategy. Existing dynamic global routing strategies only consider the congestion of neighbor nodes and the shortest path, which ignores other key nodes’ congestion on the path. With the development of detection methods and techniques, global traffic information is readily available and important for the routing choice. Reasonable use of this information can effectively improve the network routing. So, an improved global dynamic routing strategy is proposed, which considers the congestion of all nodes on the shortest path and incorporates the waiting time of the most congested node into the path. We investigate the effectiveness of the proposed routing for scale-free network with different clustering coefficients. The shortest path routing strategy and the traffic awareness routing strategy only considering the waiting time of neighbor node are analyzed comparatively. Simulation results show that network capacity is greatly enhanced compared with the shortest path; congestion state increase is relatively slow compared with the traffic awareness routing strategy. Clustering coefficient increase will not only reduce the network throughput, but also result in transmission average path length increase for scale-free network with tunable clustering. The proposed routing is favorable to ease network congestion and network routing strategy design.
Guex, Guillaume
2016-05-01
In recent articles about graphs, different models proposed a formalism to find a type of path between two nodes, the source and the target, at crossroads between the shortest-path and the random-walk path. These models include a freely adjustable parameter, allowing to tune the behavior of the path toward randomized movements or direct routes. This article presents a natural generalization of these models, namely a model with multiple sources and targets. In this context, source nodes can be viewed as locations with a supply of a certain good (e.g. people, money, information) and target nodes as locations with a demand of the same good. An algorithm is constructed to display the flow of goods in the network between sources and targets. With again a freely adjustable parameter, this flow can be tuned to follow routes of minimum cost, thus displaying the flow in the context of the optimal transportation problem or, by contrast, a random flow, known to be similar to the electrical current flow if the random-walk is reversible. Moreover, a source-targetcoupling can be retrieved from this flow, offering an optimal assignment to the transportation problem. This algorithm is described in the first part of this article and then illustrated with case studies.
An Application of Multi-Criteria Shortest Path to a Customizable Hex-Map Environment
2015-03-26
efficient shortest path algorithm into the modeling environment, namely Excel VBA . While various algorithms offer the potential for more efficiency in... model developed represents the next step in the evolution of the Metz model built by Frawley [12], which is fashioned after the WWII-inspired war game... model builds upon this foundation by improving the efficiency of the path-finding algorithm and adding the capability to define map terrain and assign a
Routing in Wireless Sensor Networks Using an Ant Colony Optimization (ACO) Router Chip.
Okdem, Selcuk; Karaboga, Dervis
2009-01-01
Wireless Sensor Networks consisting of nodes with limited power are deployed to gather useful information from the field. In WSNs it is critical to collect the information in an energy efficient manner. Ant Colony Optimization, a swarm intelligence based optimization technique, is widely used in network routing. A novel routing approach using an Ant Colony Optimization algorithm is proposed for Wireless Sensor Networks consisting of stable nodes. Illustrative examples, detailed descriptions and comparative performance test results of the proposed approach are included. The approach is also implemented to a small sized hardware component as a router chip. Simulation results show that proposed algorithm provides promising solutions allowing node designers to efficiently operate routing tasks.
Routing in Wireless Sensor Networks Using an Ant Colony Optimization (ACO Router Chip
Directory of Open Access Journals (Sweden)
Dervis Karaboga
2009-02-01
Full Text Available Wireless Sensor Networks consisting of nodes with limited power are deployed to gather useful information from the field. In WSNs it is critical to collect the information in an energy efficient manner. Ant Colony Optimization, a swarm intelligence based optimization technique, is widely used in network routing. A novel routing approach using an Ant Colony Optimization algorithm is proposed for Wireless Sensor Networks consisting of stable nodes. Illustrative examples, detailed descriptions and comparative performance test results of the proposed approach are included. The approach is also implemented to a small sized hardware component as a router chip. Simulation results show that proposed algorithm provides promising solutions allowing node designers to efficiently operate routing tasks.
Péroche, M.; Leone, F.; Gutton, R.
2014-01-01
The risk of tsunami threatens the whole Caribbean coastline especially the Lesser Antilles. The first available models of tsunami propagation estimate that the travel time from the closest seismic sources would only take few minutes to impact the Martinique Island. Considering this threat, the most effective measure is a planned and organized evacuation of the coastal population. This requires an efficient regional warning system, estimation of the maximum expected tsunami flood height, preparation of the population to evacuate, and drawing up of local and regional emergency plans. In order to produce an efficient evacuation plan, we have to assess the number of people at risk, the potential evacuation routes, the safe areas and the available time to evacuate. However, this essential information is still lacking in the French West Indies emergency plans. This paper proposes a model of tsunami evacuation sites accessibility for Martinique directly addressed to decision makers. It is based on a population database at a local scale, the development of connected graphs of roads, the identification of potential safe areas and the velocity setting for pedestrians. Evacuation routes are calculated using the Dijkstra's algorithm which gives the shortest path between areas at risk and designated evacuation sites. The first results allow us to map the theoretical times and routes to keep the exposed population safe and to compare these results with a tsunami travel time scenario.
PHA*: Finding the Shortest Path with A* in An Unknown Physical Environment
Ben-Yair, A; Kraus, S; Netanyahu, N; Stern, R; 10.1613/jair.1373
2011-01-01
We address the problem of finding the shortest path between two points in an unknown real physical environment, where a traveling agent must move around in the environment to explore unknown territory. We introduce the Physical-A* algorithm (PHA*) for solving this problem. PHA* expands all the mandatory nodes that A* would expand and returns the shortest path between the two points. However, due to the physical nature of the problem, the complexity of the algorithm is measured by the traveling effort of the moving agent and not by the number of generated nodes, as in standard A*. PHA* is presented as a two-level algorithm, such that its high level, A*, chooses the next node to be expanded and its low level directs the agent to that node in order to explore it. We present a number of variations for both the high-level and low-level procedures and evaluate their performance theoretically and experimentally. We show that the travel cost of our best variation is fairly close to the optimal travel cost, assuming t...
Directory of Open Access Journals (Sweden)
Dmitrii D. Lozovanu
2005-10-01
Full Text Available We study the max-min paths problem, which represents a game version of the shortest and the longest paths problem in a weighted directed graph. In this problem the vertex set V of the weighted directed graph G=(V,E is divided into two disjoint subsets VA and VB which are regarded as positional sets of two players. The players are seeking for a directed path from the given starting position ν 0 to the final position ν f , where the first player intends to maximize the integral cost of the path while the second one has aim to minimize it. Polynomial-time algorithm for determining max-min path in networks is proposed and its application for solving zero value cyclic games is developed. Mathematics Subject Classification 2000: 90B10, 90C35, 90C27.
Voss, Florian; Schmidt, Volker
2009-01-01
We consider spatial stochastic models, which can be applied e.g. to telecommunication networks with two hierarchy levels. In particular, we consider two Cox processes concentrated on the edge set of a random tessellation, where the points can describe the locations of low-level and high-level network components, respectively, and the edge set the underlying infrastructure of the network, like road systems, railways, etc. Furthermore, each low-level component is marked with the shortest path along the edge set to the nearest high-level component. We investigate the typical shortest path length of the resulting marked point process, which is an important characteristic e.g. in performance analysis and planning of telecommunication networks. In particular, we show that its distribution converges to simple parametric limit distributions if a certain scaling factor converges to zero and infinity, respectively. This can be used to approximate the density of the typical shortest path length by analytical formulae.
Multiple Optimal Path Identification using Ant Colony Optimisation in Wireless Sensor Network
Directory of Open Access Journals (Sweden)
Aniket. A. Gurav
2013-10-01
Full Text Available Wireless Sensor Network WSN is tightly constrained for resources like energy, computational power andmemory. Many applications of WSN require to communicate sensitive information at sensor nodes SN toBase station BS. The basic performance of WSN depends upon the path length and numbers of nodes in thepath by which data is forwarded to BS. In this paper we present bio-inspired Ant Colony Optimisation ACOalgorithm for Optimal Path Identification OPI for packet transmission to communicate between SN to BS.Our modified algorithm OPI using ACO is base-station driven which considers the path length and thenumber of hops in path for data packet transmission. This modified algorithm finds optimal path OP aswell as several suboptimal paths between SN & BS which are useful for effective communication.
Stability of Join the Shortest Queue Networks
Bramson, Maury
2010-01-01
Join the shortest queue (JSQ) refers to networks whose incoming jobs are assigned to the shortest queue from among a randomly chosen subset of the queues in the system. After completion of service at the queue, a job leaves the network. We show that, for all non- idling service disciplines and for general interarrival and service time distributions, such networks are stable when they are subcritical. We then obtain uniform bounds on the tails of the marginal distributions of the equilibria for families of such networks; these bounds are employed to show relative compactness of the marginal distributions. We also present a family of subcritical JSQ networks whose workloads in equilibrium are much larger than for the corresponding networks where each incoming job is assigned randomly to a queue. Part of this work generalizes results in Foss and Chernova [12], which applied fluid limits to study networks with the FIFO discipline. Here, we apply an appropriate Lyapunov function.
Directory of Open Access Journals (Sweden)
P. Chitra
2017-04-01
Full Text Available Recently, wireless network technologies were designed for most of the applications. Congestion raised in the wireless network degrades the performance and reduces the throughput. Congestion-free network is quit essen- tial in the transport layer to prevent performance degradation in a wireless network. Game theory is a branch of applied mathematics and applied sciences that used in wireless network, political science, biology, computer science, philosophy and economics. e great challenges of wireless network are their congestion by various factors. E ective congestion-free alternate path routing is pretty essential to increase network performance. Stackelberg game theory model is currently employed as an e ective tool to design and formulate conges- tion issues in wireless networks. is work uses a Stackelberg game to design alternate path model to avoid congestion. In this game, leaders and followers are selected to select an alternate routing path. e correlated equilibrium is used in Stackelberg game for making better decision between non-cooperation and cooperation. Congestion was continuously monitored to increase the throughput in the network. Simulation results show that the proposed scheme could extensively improve the network performance by reducing congestion with the help of Stackelberg game and thereby enhance throughput.
Routing Optimization Based on Taboo Search Algorithm for Logistic Distribution
Hongxue Yang; Lingling Xuan
2014-01-01
Along with the widespread application of the electronic commerce in the modern business, the logistic distribution has become increasingly important. More and more enterprises recognize that the logistic distribution plays an important role in the process of production and sales. A good routing for logistic distribution can cut down transport cost and improve efficiency. In order to cut down transport cost and improve efficiency, a routing optimization based on taboo search for logistic distr...
A load-balanced minimum energy routing algorithm for Wireless Ad Hoc Sensor Networks
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
Wireless Ad Hoc Sensor Networks (WSNs) have received considerable academia research attention at present. The energy-constraint sensor nodes in WSNs operate on limited batteries, so it is a very important issue to use energy efficiently and reduce power consumption. To maximize the network lifetime, it is essential to prolong each individual node's lifetime through minimizing the transmission energy consumption, so that many minimum energy routing schemes for traditional mobile ad hoc network have been developed for this reason. This paper presents a novel minimum energy routing algorithm named Load-Balanced Minimum Energy Routing (LBMER) for WSNs considering both sensor nodes' energy consumption status and the sensor nodes'hierarchical congestion levels, which uses mixture of energy balance and traffic balance to solve the problem of "hot spots" of WSNs and avoid the situation of"hot spots" sensor nodes using their energy at much higher rate and die much faster than the other nodes. The path router established by LBMER will not be very congested and the traffic will be distributed evenly in the WSNs.Simulation results verified that the LBMER performance is better than that of Min-Hop routing and the existing minimum energy routing scheme MTPR (Total Transmission Power Routing).
DEFF Research Database (Denmark)
Kulkarni, Nandkumar P.; Prasad, Neeli R.; Prasad, Ramjee
Researchers have faced numerous challenges while designing WSNs and protocols in many applications such as object tracking in military, detection of disastrous events, environment and health monitoring etc. Amongst all sustaining connectivity and capitalizing on the network lifetime is a serious...... deliberation. To tackle these two problems, Mobile Wireless Sensor Networks (MWSNs) is a better choice. In MWSN, Sensor nodes move freely to a target area without the need for any special infrastructure. Due to mobility, the routing process in MWSN has become more complicated as connections in the network can...... change dynamically. In this paper, the authors put forward an Evolutionary Mobility aware multi-objective hybrid Routing Protocol for heterogeneous wireless sensor networks (EMRP). EMRP uses two-level hierarchical clustering. EMRP selects the optimal path from source to sink using multiple metrics...
A survey of the all-pairs shortest paths problem and its variants in graphs
Directory of Open Access Journals (Sweden)
Udaya Kumar Reddy K. R.
2016-06-01
Full Text Available There has been a great deal of interest in the computation of distances and shortest paths problem in graphs which is one of the central, and most studied, problems in (algorithmic graph theory. In this paper, we survey the exact results of the static version of the all-pairs shortest paths problem and its variants namely, the Wiener index, the average distance, and the minimum average distance spanning tree (MAD tree in short in graphs (focusing mainly on algorithmic results for such problems. Along the way we also mention some important open issues and further research directions in these areas.
Institute of Scientific and Technical Information of China (English)
ZHENG Xiangquan; GUO Wei; GE Lijia; LIU Renting
2007-01-01
In order to periodically reassess the status of the alternate path route (APR) set and to improve the efficiency of alternate path construction existing in most current alternate path routing protocols,we present a cross-layer design and ant-colony optimization based load-balancing routing protocol for ad-hoc networks (CALRA) in this paper.In CALRA,the APR set maintained in nodes is aged and reassessed by the inherent mechanism of pheromone evaporation of ant-colony optimization algorithm,and load balance of network is achieved by ant-colony optimization combining with cross-layer synthetic optimization.The efficiency of APR set construction is improved by bidirectional and hop-by-hop routing update during routing discovery and routing maintenance process.Moreover,ants in CALRA deposit simulated pheromones as a function of multiple parameters corresponding to the information collected by each layer of each node visited,such as the distance from their source node,the congestion degree of the visited nodes,the current pheromones the nodes possess,the velocity of the nodes,and so on,and provide the information to the visiting nodes to update their pheromone tables by endowing the different parameters corresponding to different information and different weight values,which provides a new method to improve the congestion problem,the shortcut problem,the convergence rate and the heavy overheads commonly existed in existing ant-based routing protocols for ad-hoc networks.The performance of the algorithm is measured by the packet delivery rate,good-put ratio (routing overhead),and end-to-end delay.Simulation results show that CALRA performs well in decreasing the route overheads,balancing traffic load,as well as increasing the packet delivery rate,etc.
A reliable routing algorithm based on fuzzy Petri net in mobile ad hoc networks
Institute of Scientific and Technical Information of China (English)
HU Zhi-gang; MA Hao; WANG Guo-jun; LIAO Lin
2005-01-01
A novel reliable routing algorithm in mobile ad hoc networks using fuzzy Petri net with its reasoning mechanism was proposed to increase the reliability during the routing selection. The algorithm allows the structured representation of network topology, which has a fuzzy reasoning mechanism for finding the routing sprouting tree from the source node to the destination node in the mobile ad hoc environment. Finally, by comparing the degree of reliability in the routing sprouting tree, the most reliable route can be computed. The algorithm not only offers the local reliability between each neighboring node, but also provides global reliability for the whole selected route. The algorithm can be applied to most existing on-demand routing protocols, and the simulation results show that the routing reliability is increased by more than 80% when applying the proposed algorithm to the ad hoc on demand distance vector routing protocol.
Outdoor-indoor Space: Unified Modeling and Shortest Path Search
DEFF Research Database (Denmark)
Jensen, Søren Kejser; Nielsen, Jens Thomas Vejlby; Lu, Hua;
2016-01-01
Graph models are widely used for representing the topology of outdoor space (O-Space) and indoor space (I-Space). However, existing models neglect the intersection between O-Space and I-Space, only allowing for computations such as shortest path and nearest neighbor queries in either O-Space or I...
Fire Evacuation using Ant Colony Optimization Algorithm
National Research Council Canada - National Science Library
Kanika Singhal; Shashank Sahu
2016-01-01
... planning.The objective of the algorithm is to minimizes the entire rescue time of all evacuees.The ant colony optimization algorithm is used to solve the complications of shortest route planning. Presented paper gives a comparative overview of various emergency scenarios using ant colony optimization algorithm.
Shortest Path Planning for a Tethered Robot or an Anchored Cable
Energy Technology Data Exchange (ETDEWEB)
Xavier, P.G.
1999-02-22
We consider the problem of planning shortest paths for a tethered robot with a finite length tether in a 2D environment with polygonal obstacles. We present an algorithm that runs in time O((k{sub 1} + 1){sup 2}n{sup 4}) and finds the shortest path or correctly determines that none exists that obeys the constraints; here n is the number obstacle vertices, and k{sub 1} is the number loops in the initial configuration of the tether. The robot may cross its tether but nothing can cross obstacles, which cause the tether to bend. The algorithm applies as well for planning a shortest path for the free end of an anchored cable.
Directory of Open Access Journals (Sweden)
Adamu Murtala Zungeru
2013-01-01
Full Text Available The main problem for event gathering in wireless sensor networks (WSNs is the restricted communication range for each node. Due to the restricted communication range and high network density, event forwarding in WSNs is very challenging and requires multihop data forwarding. Currently, the energy-efficient ant based routing (EEABR algorithm, based on the ant colony optimization (ACO metaheuristic, is one of the state-of-the-art energy-aware routing protocols. In this paper, we propose three improvements to the EEABR algorithm to further improve its energy efficiency. The improvements to the original EEABR are based on the following: (1 a new scheme to intelligently initialize the routing tables giving priority to neighboring nodes that simultaneously could be the destination, (2 intelligent update of routing tables in case of a node or link failure, and (3 reducing the flooding ability of ants for congestion control. The energy efficiency improvements are significant particularly for dynamic routing environments. Experimental results using the RMASE simulation environment show that the proposed method increases the energy efficiency by up to 9% and 64% in converge-cast and target-tracking scenarios, respectively, over the original EEABR without incurring a significant increase in complexity. The method is also compared and found to also outperform other swarm-based routing protocols such as sensor-driven and cost-aware ant routing (SC and Beesensor.
Multi-Objective and Multi-Constrained Non-Additive Shortest Path Problems
DEFF Research Database (Denmark)
Reinhardt, Line Blander; Pisinger, David
of this paper is to give a general framework for dominance tests for problems involving a number of non-additive criteria. These dominance tests can help eliminate paths in a dynamic programming framework when using multiple objectives. Results on real-life multi-objective problems containing non......Shortest path problems appear as subproblems in numerous optimization problems. In most papers concerning multiple objective shortest path problems, additivity of the objective is a de-facto assumption, but in many real-life situations objectives and criteria, can be non-additive. The purpose...
Multi-Objective and Multi-Constrained Non-Additive Shortest Path Problems
DEFF Research Database (Denmark)
Reinhardt, Line Blander; Pisinger, David
2011-01-01
of this paper is to give a general framework for dominance tests for problems involving a number of non-additive criteria. These dominance tests can help to eliminate paths in a dynamic programming framework when using multiple objectives. Results on real-life multi-objective problems containing non......Shortest path problems appear as subproblems in numerous optimization problems. In most papers concerning multiple objective shortest path problems, additivity of the objective is a de-facto assumption, but in many real-life situations objectives and criteria, can be non-additive. The purpose...
Enhancing fault management performance of two-step QoS routing algorithms in GMPLS networks
Calle Ortega, Eusebi; Marzo i Lázaro, Josep Lluís; Urra i Fàbregas, Anna; Fàbrega i Soler, Lluís
2004-01-01
In this paper a novel methodology aimed at minimizing the probability of network failure and the failure impact (in terms of QoS degradation) while optimizing the resource consumption is introduced. A detailed study of MPLS recovery techniques and their GMPLS extensions are also presented. In this scenario, some features for reducing the failure impact and offering minimum failure probabilities at the same time are also analyzed. Novel two-step routing algorithms using this methodology are pr...
Real -time 3D -Route Planning Simulation Platform of UAV%无人机三维实时航迹规划仿真平台
Institute of Scientific and Technical Information of China (English)
杨文平; 李严
2011-01-01
UAV route planning is a key technology in mission planning. A safe, reliable and optimal three -di-mension flight path is found with it. In this paper, a simulation platform for UAV route planning is established by u-sing of graphical user interface development environment. A variety of threats based on terrain factors are established by digital elevation model of regular network. 3D path is planning by a method combined with improved probabilistic roadmap method (PRM) and the shortest path search Dijkstra algorithm. Multiple route planning algorithms can be search by the platform. Simulation of route planning about two - dimensional and three - dimensional, real - time and non real - time, single and multiple UAVs can be made. Through the actual operation by the platform, simulation re-sults are given to verify high efficiency of improved PRM algorithm and validity and usability of the platform.%无人机航迹规划是任务规划中的关键技术,为得到一条既安全可靠又全局代价最优的三维航迹.针对实现实时动态规划最佳航迹,利用图形用户界面开发环境,规则网格的数字高程地图模型建立了基于地形因素的多种威胁源模型,采用改进型概率地图法(probabilistic roadmap method,PRM)与最短路径搜索-Dijkstra算法相结合的方法规划了三维航迹.最终设计的平台能够实现多种航迹规划算法的搜索,二维与三维、实时与非实时、单机与多机的航迹规划仿真.通过平台的实际运行,证明了改进PRM算法的高效性,同时验证了该平台的有效性与实用性.
Evacuation Network Optimization Model with Lane-Based Reversal and Routing
Directory of Open Access Journals (Sweden)
Xing Zhao
2016-01-01
Full Text Available Sometimes, the evacuation measure may seem to be the best choice as an emergency response. To enable an efficiency evacuation, a network optimization model which integrates lane-based reversal design and routing with intersection crossing conflict elimination for evacuation is constructed. The proposed bilevel model minimizes the total evacuation time to leave the evacuation zone. A tabu search algorithm is applied to find an optimal lane reversal plan in the upper-level. The lower-level utilizes a simulated annealing algorithm to get two types of “a single arc for an intersection approach” and “multiple arcs for an intersection approach” lane-based route plans with intersection crossing conflict elimination. An experiment of a nine-intersection evacuation zone illustrates the validity of the model and the algorithm. A field case with network topology of Jianye District around the Nanjing Olympics Sports Center is studied to show the applicability of this algorithm.
Application of Fuzzy Sets for the Improvement of Routing Optimization Heuristic Algorithms
Directory of Open Access Journals (Sweden)
Mattas Konstantinos
2016-12-01
Full Text Available The determination of the optimal circular path has become widely known for its difficulty in producing a solution and for the numerous applications in the scope of organization and management of passenger and freight transport. It is a mathematical combinatorial optimization problem for which several deterministic and heuristic models have been developed in recent years, applicable to route organization issues, passenger and freight transport, storage and distribution of goods, waste collection, supply and control of terminals, as well as human resource management. Scope of the present paper is the development, with the use of fuzzy sets, of a practical, comprehensible and speedy heuristic algorithm for the improvement of the ability of the classical deterministic algorithms to identify optimum, symmetrical or non-symmetrical, circular route. The proposed fuzzy heuristic algorithm is compared to the corresponding deterministic ones, with regard to the deviation of the proposed solution from the best known solution and the complexity of the calculations needed to obtain this solution. It is shown that the use of fuzzy sets reduced up to 35% the deviation of the solution identified by the classical deterministic algorithms from the best known solution.
NHRPA: a novel hierarchical routing protocol algorithm for wireless sensor networks
Institute of Scientific and Technical Information of China (English)
CHENG Hong-bing; YANG Geng; HU Su-jun
2008-01-01
Considering severe resources constraints and security threat of wireless sensor networks (WSN), the article proposed a novel hierarchical routing protocol algorithm. The proposed routing protocol algorithm can adopt suitable routing technology for the nodes according to the distance of nodes to the base station, density of nodes distribution, and residual energy of nodes. Comparing the proposed routing protocol algorithm with simple direction diffusion routing technology, cluster-based routing mechanisms, and simple hierarchical routing protocol algorithm through comprehensive analysis and simulation in terms of the energy usage, packet latency, and security in the presence of node compromise attacks, the results show that the proposed routing protocol algorithm is more efficient for wireless sensor networks.
Directory of Open Access Journals (Sweden)
T. Karpagam
2012-01-01
Full Text Available Problem statement: Network topology design problems find application in several real life scenario. Approach: Most designs in the past either optimize for a single criterion like shortest or cost minimization or maximum flow. Results: This study discussed about solving a multi objective network topology design problem for a realistic traffic model specifically in the pipeline transportation. Here flow based algorithm focusing to transport liquid goods with maximum capacity with shortest distance, this algorithm developed with the sense of basic pert and critical path method. Conclusion/Recommendations: This flow based algorithm helps to give optimal result for transporting maximum capacity with minimum cost. It could be used in the juice factory, milk industry and its best alternate for the vehicle routing problem.
DNA Technique, cryptography, bit exchange, Genetic Algorithm
Directory of Open Access Journals (Sweden)
Meenakshi Moza
2016-07-01
Full Text Available Internet reliability and performance is based mostly on the underlying routing protocols. The current traffic load has to be taken into account for computation of paths in routing protocols. Addressing the selection of path, from a known source to destination is the basic aim of this paper. Making use of multipoint crossover and mutation is done for optimum and when required alternate path determination. Network scenario which consists of nodes that are fixed and limited to the known size of topology, comprises the population size. This paper proposes a simple method of calculating the shortest path for a network using Genetic Algorithm (GA, which is capable of giving an efficient, dynamic and consistent solution in spite of, what topology, changes in link and node happen and volume of the network. GA is used in this paper for optimization of routing. It helps us in enhancing the performance of the routers.
Genetic algorithms for route discovery.
Gelenbe, Erol; Liu, Peixiang; Lainé, Jeremy
2006-12-01
Packet routing in networks requires knowledge about available paths, which can be either acquired dynamically while the traffic is being forwarded, or statically (in advance) based on prior information of a network's topology. This paper describes an experimental investigation of path discovery using genetic algorithms (GAs). We start with the quality-of-service (QoS)-driven routing protocol called "cognitive packet network" (CPN), which uses smart packets (SPs) to dynamically select routes in a distributed autonomic manner based on a user's QoS requirements. We extend it by introducing a GA at the source routers, which modifies and filters the paths discovered by the CPN. The GA can combine the paths that were previously discovered to create new untested but valid source-to-destination paths, which are then selected on the basis of their "fitness." We present an implementation of this approach, where the GA runs in background mode so as not to overload the ingress routers. Measurements conducted on a network test bed indicate that when the background-traffic load of the network is light to medium, the GA can result in improved QoS. When the background-traffic load is high, it appears that the use of the GA may be detrimental to the QoS experienced by users as compared to CPN routing because the GA uses less timely state information in its decision making.
A Hierarchical Multiobjective Routing Model for MPLS Networks with Two Service Classes
Craveirinha, José; Girão-Silva, Rita; Clímaco, João; Martins, Lúcia
This work presents a model for multiobjective routing in MPLS networks formulated within a hierarchical network-wide optimization framework, with two classes of services, namely QoS and Best Effort (BE) services. The routing model uses alternative routing and hierarchical optimization with two optimization levels, including fairness objectives. Another feature of the model is the use of an approximate stochastic representation of the traffic flows in the network, based on the concept of effective bandwidth. The theoretical foundations of a heuristic strategy for finding “good” compromise solutions to the very complex bi-level routing optimization problem, based on a conjecture concerning the definition of marginal implied costs for QoS flows and BE flows, will be described. The main features of a first version of this heuristic based on a bi-objective shortest path model and some preliminary results for a benchmark network will also be revealed.
Ng, Hok K.; Grabbe, Shon; Mukherjee, Avijit
2010-01-01
The optimization of traffic flows in congested airspace with varying convective weather is a challenging problem. One approach is to generate shortest routes between origins and destinations while meeting airspace capacity constraint in the presence of uncertainties, such as weather and airspace demand. This study focuses on development of an optimal flight path search algorithm that optimizes national airspace system throughput and efficiency in the presence of uncertainties. The algorithm is based on dynamic programming and utilizes the predicted probability that an aircraft will deviate around convective weather. It is shown that the running time of the algorithm increases linearly with the total number of links between all stages. The optimal routes minimize a combination of fuel cost and expected cost of route deviation due to convective weather. They are considered as alternatives to the set of coded departure routes which are predefined by FAA to reroute pre-departure flights around weather or air traffic constraints. A formula, which calculates predicted probability of deviation from a given flight path, is also derived. The predicted probability of deviation is calculated for all path candidates. Routes with the best probability are selected as optimal. The predicted probability of deviation serves as a computable measure of reliability in pre-departure rerouting. The algorithm can also be extended to automatically adjust its design parameters to satisfy the desired level of reliability.
Adaptive Routing Algorithm for MANET:TERMITE
Directory of Open Access Journals (Sweden)
Sharvani G S
2009-12-01
Full Text Available Mobile Ad hoc network consists of a set of mobile nodes. This network does not have anyinfrastructure or central administration, hence it is called infrastructure less network. As the nodes aremobile, it is very difficult to find the path between two end points. This paper presents a solution forfinding path between nodes in mobile ad hoc network. Termite is an innovative algorithm for packetrouting in communication networks. Termite is an adaptive, distributed, mobile-agents-based algorithmwhich was inspired by recent work on the ant colony metaphor. According to this algorithm, a group ofmobile agents (or artificial termites build paths between pair of nodes; exploring the networkconcurrently and exchanging obtained information to update the routing tables. Some of the parametersused to evaluate its performance are packet delays and throughput. The results of this algorithm showsbetter throughput as compared to existing algorithms. So, Termite algorithm is a promising alternativefor routing of data in commercial networks.
Optimization of Operational Route in AS/RS Based on Particle Swarm Algorithm
Institute of Scientific and Technical Information of China (English)
无
2008-01-01
Optimization of the operational route in the automated storage/retrieval system (AS/RS) is transformed into the traveling salesman problem. To make the moving distance of the storage/retrieval machine shortest, we carry out a group of tests where 20 goods locations are chosed. Using PSO for operational route of AS/RS, the operation time can be shortened by about 11%. The experiments indicate that under the same conditions, the more the goods locations are, the higher the operation efficiency of the storage/retrieval machine is.
Routing Algorithm Based on Delay Rate in Wireless Cognitive Radio Network
Directory of Open Access Journals (Sweden)
Gan Yan
2014-04-01
Full Text Available To reduce the end-to-end average delay of algorithm in wireless network, this paper proposes the real-time routing algorithm in spectrum network. It is analyzed that the dynamic changes of the radio network model and routing algorithm in spectrum network. Through using Markov state transition and adjusting the router with scaling factor, the high-quality resources in the network can be obtained and fully utilized, and then these can reduce the transmission time latency rate and timely adjust the route. After that the tendency of spectrum network and specific real-time algorithm are given. Finally, by using the network simulation NS-2, simulation experiments are used to estimate the performance test. Experimental results show that compared with the traditional algorithm, the proposed algorithm can obtain a lower end-to-end average delay and improves network throughput and the steady and reliability of the link connection.
Exact and Heuristic Algorithms for Routing AGV on Path with Precedence Constraints
Directory of Open Access Journals (Sweden)
Liang Xu
2016-01-01
Full Text Available A new problem arises when an automated guided vehicle (AGV is dispatched to visit a set of customers, which are usually located along a fixed wire transmitting signal to navigate the AGV. An optimal visiting sequence is desired with the objective of minimizing the total travelling distance (or time. When precedence constraints are restricted on customers, the problem is referred to as traveling salesman problem on path with precedence constraints (TSPP-PC. Whether or not it is NP-complete has no answer in the literature. In this paper, we design dynamic programming for the TSPP-PC, which is the first polynomial-time exact algorithm when the number of precedence constraints is a constant. For the problem with number of precedence constraints, part of the input can be arbitrarily large, so we provide an efficient heuristic based on the exact algorithm.
Directory of Open Access Journals (Sweden)
Imen Châari
2014-07-01
Full Text Available Path planning is a fundamental optimization problem that is crucial for the navigation of a mobile robot. Among the vast array of optimization approaches, we focus in this paper on Ant Colony Optimization (ACO and Genetic Algorithms (GA for solving the global path planning problem in a static environment, considering their effectiveness in solving such a problem. Our objective is to design an efficient hybrid algorithm that takes profit of the advantages of both ACO and GA approaches for the sake of maximizing the chance to find the optimal path even under real-time constraints. In this paper, we present smartPATH, a new hybrid ACO-GA algorithm that relies on the combination of an improved ACO algorithm (IACO for efficient and fast path selection, and a modified crossover operator to reduce the risk of falling into a local minimum. We demonstrate through extensive simulations that smartPATH outperforms classical ACO (CACO, GA algorithms. It also outperforms the Dijkstra exact method in solving the path planning problem for large graph environments. It improves the solution quality up to 57% in comparison with CACO and reduces the execution time up to 83% as compared to Dijkstra for large and dense graphs. In addition, the experimental results on a real robot shows that smartPATH finds the optimal path with a probability up to 80% with a small gap not exceeding 1m in 98%.
Location-Based Self-Adaptive Routing Algorithm for Wireless Sensor Networks in Home Automation
Directory of Open Access Journals (Sweden)
Hong SeungHo
2011-01-01
Full Text Available The use of wireless sensor networks in home automation (WSNHA is attractive due to their characteristics of self-organization, high sensing fidelity, low cost, and potential for rapid deployment. Although the AODVjr routing algorithm in IEEE 802.15.4/ZigBee and other routing algorithms have been designed for wireless sensor networks, not all are suitable for WSNHA. In this paper, we propose a location-based self-adaptive routing algorithm for WSNHA called WSNHA-LBAR. It confines route discovery flooding to a cylindrical request zone, which reduces the routing overhead and decreases broadcast storm problems in the MAC layer. It also automatically adjusts the size of the request zone using a self-adaptive algorithm based on Bayes' theorem. This makes WSNHA-LBAR more adaptable to the changes of the network state and easier to implement. Simulation results show improved network reliability as well as reduced routing overhead.
Finding the K shortest hyperpaths using reoptimization
DEFF Research Database (Denmark)
Nielsen, Lars Relund; Pretolani, Daniele; Andersen, Kim Allan
2004-01-01
The shortest hyperpath problem is an extension of the classical shortest path problem and has applications in many different areas. Recently, algorithms for finding the K shortest hyperpaths in a directed hypergraph have been developed by Andersen, Nielsen and Pretolani. In this paper we improve...... the worst-case computational complexity of an algorithm for finding the K shortest hyperpaths in an acyclic hypergraph. This result is obtained by applying new reoptimization techniques for shortest hyperpaths. The algorithm turns out to be quite effective in practice and has already been successfully...... applied in the context of stochastic time-dependent networks, for finding the K best strategies and for solving bicriterion problems....
Finding the K shortest hyperpaths using reoptimization
DEFF Research Database (Denmark)
Nielsen, Lars Relund; Pretolani, Daniele; Andersen, Kim Allan
2004-01-01
The shortest hyperpath problem is an extension of the classical shortest path problem and has applications in many different areas. Recently, algorithms for finding the K shortest hyperpaths in a directed hypergraph have been developed by Andersen, Nielsen and Pretolani. In this paper we improve...... the worst-case computational complexity of an algorithm for finding the K shortest hyperpaths in an acyclic hypergraph. This result is obtained by applying new reoptimization techniques for shortest hyperpaths. The algorithm turns out to be quite effective in practice and has already been successfully...... applied in the context of stochastic time-dependent networks, for finding the K best strategies and for solving bicriterion problems....
Finding the K shortest hyperpaths using reoptimization
DEFF Research Database (Denmark)
Nielsen, Lars Relund; Pretolani, Daniele; Andersen, Kim Allan
2006-01-01
The shortest hyperpath problem is an extension of the classical shortest path problem and has applications in many different areas. Recently, algorithms for finding the K shortest hyperpaths in a directed hypergraph have been developed by Andersen, Nielsen and Pretolani. In this paper we improve...... the worst-case computational complexity of an algorithm for finding the K shortest hyperpaths in an acyclic hypergraph. This result is obtained by applying new reoptimization techniques for shortest hyperpaths. The algorithm turns out to be quite effective in practice and has already been successfully...... applied in the context of stochastic time-dependent networks, for finding the K best strategies and for solving bicriterion problems...
A Rough Penalty Genetic Algorithm for Multicast Routing in Mobile Ad Hoc Networks
Directory of Open Access Journals (Sweden)
Chih-Hao Lin
2013-01-01
Full Text Available Multicast routing is an effective way to transmit messages to multiple hosts in a network. However, it is vulnerable to intermittent connectivity property in mobile ad hoc network (MANET especially for multimedia applications, which have some quality of service (QoS requirements. The goal of QoS provisioning is to well organize network resources to satisfy the QoS requirement and achieve good network delivery services. However, there remains a challenge to provide QoS solutions and maintain end-to-end QoS with user mobility. In this paper, a novel penalty adjustment method based on the rough set theory is proposed to deal with path-delay constraints for multicast routing problems in MANETs. We formulate the problem as a constrained optimization problem, where the objective function is to minimize the total cost of the multicast tree subject to QoS constraints. The RPGA is evaluated on three multicast scenarios and compared with two state-of-the-art methods in terms of cost, success rate, and time complexity. The performance analyses show that this approach is a self-adaptive method for penalty adjustment. Remarkably, the method can address a variety of constrained multicast routing problems even though the initial routes do not satisfy all QoS requirements.
COMPUTER REALIZATION OF SEARCH TASK OF THE SHORTEST ROUTE WITH THE HELP OF EXCEL AND VBA
2008-01-01
The necessity of the development of simple and accessible to the final users of the applied software for the decision of local optimization tasks of transport technologies has been grounded with the help of the Excel and VBA facilities. The computer task decision and search of the shortest route has been described.
Optimized algorithm for balancing clusters in wireless sensor networks
Institute of Scientific and Technical Information of China (English)
Mucheol KIM; Sun-hong KIM; Hyungjin BYUN; Sang-yong HAN
2009-01-01
Wireless sensor networks consist of hundreds or thousands of sensor nodes that involve numerous restrictions including computation capability and battery capacity. Topology control is an important issue for achieving a balanced placement of sensor nodes. The clustering scheme is a widely known and efficient means of topology control for transmitting information to the base station in two hops. The automatic routing scheme of the self-organizing technique is another critical element of wireless sensor networks. In this paper we propose an optimal algorithm with cluster balance taken into consideration, and compare it with three well known and widely used approaches, I.e., LEACH, MEER, and VAP-E, in performance evaluation. Experimental results show that the proposed approach increases the overall network lifetime, indicating that the amount of energy required for communication to the base station will be reduced for locating an optimal cluster.
An optimization algorithm for a capacitated vehicle routing problem with time windows
Indian Academy of Sciences (India)
PINAR KIRCI
2016-05-01
In this paper, vehicle routing problem (VRP) with time windows and real world constraints are considered as a real-world application on google maps. Also, tabu search is used and Hopfield neural networks is utilized. Basic constraints consist of customer demands, time windows, vehicle speed, vehicle capacity andworking hours. Recently, cost and on-time delivery are the most important actors in logistics. Thus, the logistic applications attract attention of companies. In logistic management, determining the locations of delivery points and deciding the path are the vital components that should be considered. Deciding the paths of vehicles provides companies to use their vehicles efficiently. And with utilizing optimized paths, big amounts of cost and time savings will be gained. The main aim of the work is providing the best path according to the needs of the customers, minimizing the costs with utilizing the VRP and presenting an application for companies that need logistic management. To compare the results, simulated annealing is used on special scenarios. And t-test is performed in the study for the visited path in km with p-value of 0.05.
Dynamic Routing Algorithm for Satellite Network Based on Ant Colony Algorithm%基于蚁群算法的卫星网动态路由算法
Institute of Scientific and Technical Information of China (English)
马海滨; 王汝传; 饶元
2011-01-01
卫星网络路由应当具有使用较小的通信开销和处理能力计算出最优路径,并能够适应卫星网络拓扑结构动态变化等特点,这与蚁群算法的特征相匹配,能很好地解决这一问题.以此为背景,提出了一种新型的基于蚁群算法的卫星网动态路由算法(DRAS-ACA),并在NS2网络仿真平台上实现了该路由算法,使用gnuplot分析了仿真结果.%Satellite network routing should have the use of smaller capacity and communication overhead to calculate the optimal path, and be able to adapt to the satellite network topology changes, and other characteristics. The Ant Colony Algorithm should be a good appraach to solve this problem. In this paper, a dynamic routing algorithm for satellite network based on ant colony algorithm (DRAS-ACA) was presented and simulated on NS2 platform,and we also analyzed the simulation results with gnuplot.
An improved least cost routing approach for WDM optical network without wavelength converters
Bonani, Luiz H.; Forghani-elahabad, Majid
2016-12-01
Routing and wavelength assignment (RWA) problem has been an attractive problem in optical networks, and consequently several algorithms have been proposed in the literature to solve this problem. The most known techniques for the dynamic routing subproblem are fixed routing, fixed-alternate routing, and adaptive routing methods. The first one leads to a high blocking probability (BP) and the last one includes a high computational complexity and requires immense backing from the control and management protocols. The second one suggests a trade-off between performance and complexity, and hence we consider it to improve in our work. In fact, considering the RWA problem in a wavelength routed optical network with no wavelength converter, an improved technique is proposed for the routing subproblem in order to decrease the BP of the network. Based on fixed-alternate approach, the first k shortest paths (SPs) between each node pair is determined. We then rearrange the SPs according to a newly defined cost for the links and paths. Upon arriving a connection request, the sorted paths are consecutively checked for an available wavelength according to the most-used technique. We implement our proposed algorithm and the least-hop fixed-alternate algorithm to show how the rearrangement of SPs contributes to a lower BP in the network. The numerical results demonstrate the efficiency of our proposed algorithm in comparison with the others, considering different number of available wavelengths.
A Scheme to Optimize Flow Routing and Polling Switch Selection of Software Defined Networks.
Directory of Open Access Journals (Sweden)
Huan Chen
Full Text Available This paper aims at minimizing the communication cost for collecting flow information in Software Defined Networks (SDN. Since flow-based information collecting method requires too much communication cost, and switch-based method proposed recently cannot benefit from controlling flow routing, jointly optimize flow routing and polling switch selection is proposed to reduce the communication cost. To this end, joint optimization problem is formulated as an Integer Linear Programming (ILP model firstly. Since the ILP model is intractable in large size network, we also design an optimal algorithm for the multi-rooted tree topology and an efficient heuristic algorithm for general topology. According to extensive simulations, it is found that our method can save up to 55.76% communication cost compared with the state-of-the-art switch-based scheme.
A novel communication mechanism based on node potential multi-path routing
Bu, Youjun; Zhang, Chuanhao; Jiang, YiMing; Zhang, Zhen
2016-10-01
With the network scales rapidly and new network applications emerge frequently, bandwidth supply for today's Internet could not catch up with the rapid increasing requirements. Unfortunately, irrational using of network sources makes things worse. Actual network deploys single-next-hop optimization paths for data transmission, but such "best effort" model leads to the imbalance use of network resources and usually leads to local congestion. On the other hand Multi-path routing can use the aggregation bandwidth of multi paths efficiently and improve the robustness of network, security, load balancing and quality of service. As a result, multi-path has attracted much attention in the routing and switching research fields and many important ideas and solutions have been proposed. This paper focuses on implementing the parallel transmission of multi next-hop data, balancing the network traffic and reducing the congestion. It aimed at exploring the key technologies of the multi-path communication network, which could provide a feasible academic support for subsequent applications of multi-path communication networking. It proposed a novel multi-path algorithm based on node potential in the network. And the algorithm can fully use of the network link resource and effectively balance network link resource utilization.
Optimal Path Choice in Railway Passenger Travel Network Based on Residual Train Capacity
Directory of Open Access Journals (Sweden)
Fei Dou
2014-01-01
Full Text Available Passenger’s optimal path choice is one of the prominent research topics in the field of railway passenger transport organization. More and more different train types are available, increasing path choices from departure to destination for travelers are unstoppable. However, travelers cannot avoid being confused when they hope to choose a perfect travel plan based on various travel time and cost constraints before departure. In this study, railway passenger travel network is constructed based on train timetable. Both the generalized cost function we developed and the residual train capacity are considered to be the foundation of path searching procedure. The railway passenger travel network topology is analyzed based on residual train capacity. Considering the total travel time, the total travel cost, and the total number of passengers, we propose an optimal path searching algorithm based on residual train capacity in railway passenger travel network. Finally, the rationale of the railway passenger travel network and the optimal path generation algorithm are verified positively by case study.
Optimal path choice in railway passenger travel network based on residual train capacity.
Dou, Fei; Yan, Kai; Huang, Yakun; Wang, Li; Jia, Limin
2014-01-01
Passenger's optimal path choice is one of the prominent research topics in the field of railway passenger transport organization. More and more different train types are available, increasing path choices from departure to destination for travelers are unstoppable. However, travelers cannot avoid being confused when they hope to choose a perfect travel plan based on various travel time and cost constraints before departure. In this study, railway passenger travel network is constructed based on train timetable. Both the generalized cost function we developed and the residual train capacity are considered to be the foundation of path searching procedure. The railway passenger travel network topology is analyzed based on residual train capacity. Considering the total travel time, the total travel cost, and the total number of passengers, we propose an optimal path searching algorithm based on residual train capacity in railway passenger travel network. Finally, the rationale of the railway passenger travel network and the optimal path generation algorithm are verified positively by case study.
A Hybrid Adaptive Routing Algorithm for Event-Driven Wireless Sensor Networks
Directory of Open Access Journals (Sweden)
Antonio A. F. Loureiro
2009-09-01
Full Text Available Routing is a basic function in wireless sensor networks (WSNs. For these networks, routing algorithms depend on the characteristics of the applications and, consequently, there is no self-contained algorithm suitable for every case. In some scenarios, the network behavior (traffic load may vary a lot, such as an event-driven application, favoring different algorithms at different instants. This work presents a hybrid and adaptive algorithm for routing in WSNs, called Multi-MAF, that adapts its behavior autonomously in response to the variation of network conditions. In particular, the proposed algorithm applies both reactive and proactive strategies for routing infrastructure creation, and uses an event-detection estimation model to change between the strategies and save energy. To show the advantages of the proposed approach, it is evaluated through simulations. Comparisons with independent reactive and proactive algorithms show improvements on energy consumption.
A hybrid adaptive routing algorithm for event-driven wireless sensor networks.
Figueiredo, Carlos M S; Nakamura, Eduardo F; Loureiro, Antonio A F
2009-01-01
Routing is a basic function in wireless sensor networks (WSNs). For these networks, routing algorithms depend on the characteristics of the applications and, consequently, there is no self-contained algorithm suitable for every case. In some scenarios, the network behavior (traffic load) may vary a lot, such as an event-driven application, favoring different algorithms at different instants. This work presents a hybrid and adaptive algorithm for routing in WSNs, called Multi-MAF, that adapts its behavior autonomously in response to the variation of network conditions. In particular, the proposed algorithm applies both reactive and proactive strategies for routing infrastructure creation, and uses an event-detection estimation model to change between the strategies and save energy. To show the advantages of the proposed approach, it is evaluated through simulations. Comparisons with independent reactive and proactive algorithms show improvements on energy consumption.
Low Carbon Footprint Routes for Bird Watching
Directory of Open Access Journals (Sweden)
Wei-Ta Fang
2015-03-01
Full Text Available Bird watching is one of many recreational activities popular in ecotourism. Its popularity, therefore, prompts the need for studies on energy conservation. One such environmentally friendly approach toward minimizing bird watching’s ecological impact is ensuring a reduced carbon footprint by using an economic travel itinerary comprising a series of connected routes between tourist attractions that minimizes transit time. This study used a travel-route planning approach using geographic information systems to detect the shortest path, thereby solving the problems associated with time-consuming transport. Based on the results of road network analyses, optimal travel-route planning can be determined. These methods include simulated annealing (SA and genetic algorithms (GA. We applied two algorithms in our simulation research to detect which one is an appropriate algorithm for running carbon-routing algorithms at the regional scale. SA, which is superior to GA, is considered an excellent approach to search for the optimal path to reduce carbon dioxide and high gasoline fees, thereby controlling travel time by using the shortest travel routes.
Hybrid discrete particle swarm optimization algorithm for capacitated vehicle routing problem
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
Capacitated vehicle routing problem (CVRP) is an NP-hard problem. For large-scale problems, it is quite difficult to achieve an optimal solution with traditional optimization methods due to the high computational complexity. A new hybrid approximation algorithm is developed in this work to solve the problem. In the hybrid algorithm, discrete particle swarm optimization (DPSO) combines global search and local search to search for the optimal results and simulated annealing (SA) uses certain probability to avoid being trapped in a local optimum. The computational study showed that the proposed algorithm is a feasible and effective approach for capacitated vehicle routing problem, especially for large scale problems.
Weighted deductive parsing and Knuth's algorithm - Squibs and discussions
Nederhof, MJ
2003-01-01
We discuss weighted deductive parsing and consider the problem of finding the derivation with the lowest weight. We show that Knuth's generalization of Dijkstra's algorithm for the shortest-path problem offers a general method to solve this problem. Our approach is modular in the sense that Knuth's
A Layered Zone Routing Algorithm in Ad Hoc Network Based on Matrix of Adjacency Connection
Institute of Scientific and Technical Information of China (English)
XU Guang-wei; LI Feng; SHI Xiu-jin; HUO Jia-zhen
2007-01-01
The hybrid routing protocol has received more attention recently than the proactive and the reactive, especially for large-scale and highly dynamic connection, in mobile ad hoc network. A crucial reason is that zone-layered is being utilized in the complex systems. A hybrid routing algorithm which is layered zone based on adjacency connection(LZBAC) is put forward under the background of a few members in network with steady position and link. The algorithm modifies storage structure of nodes and improves routing mechanism. The theoretical analysis and simulation testing testify that the algorithm costs shorter time of route finding and less delay than others.
Directory of Open Access Journals (Sweden)
Mohammed Zaki Hasan
2013-01-01
Full Text Available Multimedia sensor networks for real-time applications have strict constraints on delay, packet loss, and energy consumption requirements. For example, video streaming in a disaster-management scenario requires careful handling to ensure that the end-to-end delay is within the acceptable range and the video is received properly without any distortion. The failure to transmit a video stream effectively occurs for many reasons, including sensor function limitations, excessive power consumption, and a lack of routing reliability. We propose a novel mathematical model for quality of service (QoS route determination that enables a sensor to determine the optimal path for minimising resource use while satisfying the required QoS constraints. The proposed mathematical model uses the Lagrangian relaxation mixed integer programming technique to define critical parameters and appropriate objective functions for controlling the adaptive QoS constrained route discovery process. Performance trade-offs between QoS requirements and energy efficiency were simulated using the LINGO mathematical programming language. The proposed approach significantly improves the network lifetime, while reducing energy consumption and decreasing average end-to-end delays within the sensor network via optimised resource sharing in intermediate nodes compared with existing routing algorithms.
A hybrid GA-TS algorithm for open vehicle routing optimization of coal mines material
Energy Technology Data Exchange (ETDEWEB)
Yu, S.W.; Ding, C.; Zhu, K.J. [China University of Geoscience, Wuhan (China)
2011-08-15
In the open vehicle routing problem (OVRP), the objective is to minimize the number of vehicles and the total distance (or time) traveled. This study primarily focuses on solving an open vehicle routing problem (OVRP) by applying a novel hybrid genetic algorithm and the Tabu search (GA-TS), which combines the GA's parallel computing and global optimization with TS's Tabu search skill and fast local search. Firstly, the proposed algorithm uses natural number coding according to the customer demands and the captivity of the vehicle for globe optimization. Secondly, individuals of population do TS local search with a certain degree of probability, namely, do the local routing optimization of all customer sites belong to one vehicle. The mechanism not only improves the ability of global optimization, but also ensures the speed of operation. The algorithm was used in Zhengzhou Coal Mine and Power Supply Co., Ltd.'s transport vehicle routing optimization.
Dynamic Vehicle Routing for Robotic Networks: Models, Fundamental Limitations and Algorithms
2010-04-16
partitions. SIAM Review, January 2010. Submitted Francesco Bullo (UCSB) Dynamic Vehicle Routing 16apr10 @ ARL 31 / 34 Gossip partitioning policy: sample...Control Conference, Hollywood, CA, October 2009 Francesco Bullo (UCSB) Dynamic Vehicle Routing 16apr10 @ ARL 32 / 34 Gossip partitioning policy: analysis...Dynamic Vehicle Routing for Robotic Networks: Models, Fundamental Limitations and Algorithms Francesco Bullo Center for Control, Dynamical Systems
Le, Viet-Duc; Scholten, Hans; Havinga, Paul
2012-01-01
Recently the increasing number of sensors integrated in smartphones, especially the iPhone and Android phones, has motivated the development of routing algorithms for Opportunistic Mobile Sensor Networks (OppMSNs). Although there are many existing opportunistic routing algorithms, researchers still
Improved AODV route recovery in mobile ad-hoc networks using a genetic algorithm
Directory of Open Access Journals (Sweden)
Ahmad Maleki
2014-09-01
Full Text Available An important issue in ad-hoc on-demand distance vector (AODV routing protocols is route failure caused by node mobility in the MANETs. The AODV requires a new route discovery procedure whenever a route breaks and these frequent route discoveries increase transmission delays and routing overhead. The present study proposes a new method for AODVs using a genetic algorithm to improve the route recovery mechanism. When failure occurs in a route, the proposed method (GAAODV makes decisions regarding the QOS parameter to select source or local repair. The task of the genetic algorithm is to find an appropriate combination of weights to optimize end-to-end delay. This paper evaluates the metrics of routing overhead, average end-to-end delay, and packet delivery ratio. Comparison of the new algorithm and AODV (RFC 3561 using a NS-2 simulator shows that GAAODV obtains better results for the QOS parameters.
Power-Aware Anycast Routing in Wireless Sensor Network Exploiting Small World Effect
Institute of Scientific and Technical Information of China (English)
JIANG Nan; YANG Shu-qun; LI Ling-zhi; DING Qiu-lin
2008-01-01
By considering energy-efficient anycast routing in wireless sensor network (WSN), and combining small world characteristics of WSN with the properties of the ant algorithm, a power-aware anycast routing algorithm (SWPAR) with multi-sink nodes is proposed and evaluated. By SWPAR, the optimal sink node is found and the problem of routing path is effectively solved. Simulation results show that compared with the sink-based anycast routing protocol (SARP) and the hierarchy-based anycast routing protocol (HARP), the proposed algorithm improves network lifetime and reduces power consumption.
Optimal evacuation routes on cruise ship in fire based on equivalent length%基于当量长度的游船火灾人员最优疏散路径
Institute of Scientific and Technical Information of China (English)
刘红; 罗旋
2012-01-01
In order to select a reasonable evacuation route to avoid or reduce injuries and deaths when the fire breaks out on cruise ship, the equivalent length is introduced to establish the cruise ship emergency evacuation model in case of fire. Dijkstra algorithm is adopted to get multiple shortest evacuation routes between the disaster area and the emergency exits, and the solutions are obtained by MATLAB. Cruise ship "Ocean Oasis" is selected to do the empirical research. In the case that fire in passenger cabin is known, the influences of path occupation and the expanding of fire on the optimal evacuation routes are discussed. The result shows that the evacuation model is of reliability.%为能够在游船发生火灾时选择合理的疏散路径,避免和减少人员伤亡,引入当量长度,建立火灾时游船应急疏散模型,选用最短路径算法得到火灾区域至各逃生出口的多条最优疏散路径,并利用MATLAB编程实现.选取“海洋绿洲”号游船进行实证研究,在客舱着火点位置确定的情况下分别考虑游船通道阻塞和火灾扩散对最优疏散路径的影响.研究结果表明,所建立的疏散模型是可靠的.
An Efficient Data-Gathering Routing Protocol for Underwater Wireless Sensor Networks
Directory of Open Access Journals (Sweden)
Nadeem Javaid
2015-11-01
Full Text Available Most applications of underwater wireless sensor networks (UWSNs demand reliable data delivery over a longer period in an efficient and timely manner. However, the harsh and unpredictable underwater environment makes routing more challenging as compared to terrestrial WSNs. Most of the existing schemes deploy mobile sensors or a mobile sink (MS to maximize data gathering. However, the relatively high deployment cost prevents their usage in most applications. Thus, this paper presents an autonomous underwater vehicle (AUV-aided efficient data-gathering (AEDG routing protocol for reliable data delivery in UWSNs. To prolong the network lifetime, AEDG employs an AUV for data collection from gateways and uses a shortest path tree (SPT algorithm while associating sensor nodes with the gateways. The AEDG protocol also limits the number of associated nodes with the gateway nodes to minimize the network energy consumption and to prevent the gateways from overloading. Moreover, gateways are rotated with the passage of time to balance the energy consumption of the network. To prevent data loss, AEDG allows dynamic data collection at the AUV depending on the limited number of member nodes that are associated with each gateway. We also develop a sub-optimal elliptical trajectory of AUV by using a connected dominating set (CDS to further facilitate network throughput maximization. The performance of the AEDG is validated via simulations, which demonstrate the effectiveness of AEDG in comparison to two existing UWSN routing protocols in terms of the selected performance metrics.
An Efficient Data-Gathering Routing Protocol for Underwater Wireless Sensor Networks.
Javaid, Nadeem; Ilyas, Naveed; Ahmad, Ashfaq; Alrajeh, Nabil; Qasim, Umar; Khan, Zahoor Ali; Liaqat, Tayyaba; Khan, Majid Iqbal
2015-11-17
Most applications of underwater wireless sensor networks (UWSNs) demand reliable data delivery over a longer period in an efficient and timely manner. However, the harsh and unpredictable underwater environment makes routing more challenging as compared to terrestrial WSNs. Most of the existing schemes deploy mobile sensors or a mobile sink (MS) to maximize data gathering. However, the relatively high deployment cost prevents their usage in most applications. Thus, this paper presents an autonomous underwater vehicle (AUV)-aided efficient data-gathering (AEDG) routing protocol for reliable data delivery in UWSNs. To prolong the network lifetime, AEDG employs an AUV for data collection from gateways and uses a shortest path tree (SPT) algorithm while associating sensor nodes with the gateways. The AEDG protocol also limits the number of associated nodes with the gateway nodes to minimize the network energy consumption and to prevent the gateways from overloading. Moreover, gateways are rotated with the passage of time to balance the energy consumption of the network. To prevent data loss, AEDG allows dynamic data collection at the AUV depending on the limited number of member nodes that are associated with each gateway. We also develop a sub-optimal elliptical trajectory of AUV by using a connected dominating set (CDS) to further facilitate network throughput maximization. The performance of the AEDG is validated via simulations, which demonstrate the effectiveness of AEDG in comparison to two existing UWSN routing protocols in terms of the selected performance metrics.
Vehicle Routing Optimization in Logistics Distribution Using Hybrid Ant Colony Algorithm
Directory of Open Access Journals (Sweden)
Chengming Qi
2013-09-01
Full Text Available The Vehicle Routing Problem (VRP is an important management problem in the field of physical distribution and logistics. Good vehicle routing can not only increase the profit of logistics but also make logistics management more scientific. The Capacitated Vehicle Routing Problem (CVRP constrained by the capacity of a vehicle is the extension of VRP. Our research applies a two-phase algorithm to address CVRP. It takes the advantages of Simulated Annealing (SA and ant colony optimization for solving the capacitated vehicle routing problem. In the first phase of proposed algorithm, simulated annealing provides a good initial solution for ant colony optimization. In the second phase, Iterative Local Search (ILS method is employed to seeking the close-to-optimal solution in local scope based on the capacity of the vehicle. Experimental results show that the proposed algorithm is superior to original ant colony optimization and simulated annealing separately reported on partial benchmark problems.
2011-09-01
reconfigurations. Proposals that optimize OSPF or IS-IS link weights with failures in mind, such as [34] and [72], must rely on shortest path IGP routing...tolerant layer 2 data center network fabric. In Proc. of ACM SIGCOMM, pages 39–50, 2009. [72] A. Nucci, S. Bhattacharyya, N. Taft, and C. Diot. IGP link
Optimal Routing for Decode-and-Forward based Cooperation in Wireless Networks
Ong, Lawrence
2007-01-01
We investigate cooperative wireless relay networks in which the nodes can help each other in data transmission. We study different coding strategies in the single-source single-destination network with many relay nodes. Given the myriad of ways in which nodes can cooperate, there is a natural routing problem, i.e., determining an ordered set of nodes to relay the data from the source to the destination. We find that for a given route, the decode-and-forward strategy, which is an information theoretic cooperative coding strategy, achieves rates significantly higher than that achievable by the usual multi-hop coding strategy, which is a point-to-point non-cooperative coding strategy. We construct an algorithm to find an optimal route (in terms of rate maximizing) for the decode-and-forward strategy. Since the algorithm runs in factorial time in the worst case, we propose a heuristic algorithm that runs in polynomial time. The heuristic algorithm outputs an optimal route when the nodes transmit independent codew...
基于业务感知和策略选择的认知路由算法%Cognitive network routing algorithm based on service awareness and policy choice
Institute of Scientific and Technical Information of China (English)
顾成杰; 张顺颐; 孙雁飞
2011-01-01
A cognitive network routing (CNR) algorithm based on service awareness and policy choice oriented to cognitive network was proposed. This algorithm takes network resource, flow, policy choice into account and obtains the flow characteristics and network resources condition in advance. CNR algorithm fulfills the distribution of resources through offline network allocation and gets the optimal path of each flow by online path computation. Simulation verified the effectiveness of cognitive network routing algorithm and showed that compared with the traditional routing algorithms, the cognitive network routing algorithm can improve the cognitive utilization of network resources, avoid network congestion coursed by resources allocation and optimize network performance at different levels.%提出了一种基于业务感知和策略选择的认知路由(cognitive network routing)算法.该算法面向认知网络环境综合考虑了网络资源、业务流、策略选择等要素,在获知网络中业务流的宏观特征和需求的前提下,首先通过离线资源分配将网络资源按照业务流的固有分配特征预先配置给不同类型的业务流,然后通过在线路径计算实时得出各个业务流的最优路径.仿真实验验证了认知路由算法的有效性,对比于MIRA、SWP路由算法,CNR算法可以提高网络资源利用率,避免因资源不均衡产生的网络拥塞,能够在业务流和资源2个层面优化网络性能.
The d-edge shortest-path problem for a Monge graph
Energy Technology Data Exchange (ETDEWEB)
Bein, W.W. [New Mexico Univ., Albuquerque, NM (United States). Dept. of Computer Science; Larmore, L.L. [California Univ., Riverside, CA (United States). Dept. of Computer Science; Park, J.K. [Sandia National Labs.,Albuquerque, NM (United States)
1992-07-14
A complete edge-weighted directed graph on vertices 1,2,...,n that assigns cost c(i,j) to the edge (i,j) is called Monge if its edge costs form a Monge array, i.e., for all i < k and j < l, c[i, j]+c[k,l]{le} < c[i,l]+c[k,j]. One reason Monge graphs are interesting is that shortest paths can be computed quite quickly in such graphs. In particular, Wilber showed that the shortest path from vertex 1 to vertex n of a Monge graph can be computed in O(n) time, and Aggarwal, Klawe, Moran, Shor, and Wilber showed that the shortest d-edge 1-to-n path (i.e., the shortest path among all 1-to-n paths with exactly d edges) can be computed in O(dn) time. This paper`s contribution is a new algorithm for the latter problem. Assuming 0 {le} c[i,j] {le} U and c[i,j + 1] + c[i + 1,j] {minus} c[i,j] {minus} c[i + 1, j + 1] {ge} L > 0 for all i and j, our algorithm runs in O(n(1 + 1g(U/L))) time. Thus, when d {much_gt} 1 + 1g(U/L), our algorithm represents a significant improvement over Aggarwal et al.`s O(dn)-time algorithm. We also present several applications of our algorithm; they include length-limited Huffman coding, finding the maximum-perimeter d-gon inscribed in a given convex n-gon, and a digital-signal-compression problem.
Structural parcellation of the thalamus using shortest-path tractography
DEFF Research Database (Denmark)
Kasenburg, Niklas; Darkner, Sune; Hahn, Ute;
2016-01-01
that parcellation of the thalamus results in p-value maps that are spatially coherent across subjects. Comparing to the state-of-the-art parcellation of Behrens et al. [1], we observe some agreement, but the soft segmentation exhibits better stability for voxels connected to multiple target regions....... to each cortical target region. Calculation of these statistical measures is derived from a rank-based test on the histogram of tract-based scores from all the shortest paths found between the source voxel and each voxel within the target region. Using data from the Human Connectome Project, we show...
Multicost Routing Approach in Wireless Ad hoc Networks
Directory of Open Access Journals (Sweden)
P. Ramamoorthy
2012-01-01
Full Text Available Problem statement: A Wireless ad hoc network is a collection of autonomous movable nodes that communicate with each other over wireless links without any static infrastructure. In these networks there is no fixed topology because of the mobility of nodes, interference, multipath propagation and path loss. A variety of routing protocols and algorithm with varying network settings are analyzed to link between the nodes and communicate packets to their destinations. Most of these algorithms are single cost, in the logic that they consign a scalar cost parameter to every link and compute the path that has minimum cost. Although multicost routing, a vector of cost parameters is consigned to each link and the cost vector of a path is well-defined based on the cost vectors of the links that embrace it. Adjustable transmission power control of the nodes with multi cost routing algorithm can support optimizeto acquire the reduced interference and improve the ad hoc network performance. Approach: The link and path of the wireless network is consigned with several cost parameters. Hop count, total interference, node link delay, residual energy of a node and the node transmission power are the cost parameters assigned for link and path of the ad hoc networks. Multicost parameters are combined in different optimization function with respect to various routing algorithm. Results: Simulation and optimization shows multicost SUM/MIN Energy-Interference algorithm with variable transmission power can lead to decrease the interference and improves the overall network performance. Conclusion: The function optimized for wireless ad hoc networks that the Multicost SUM/MIN Energy-Interference algorithm achieves improved performance over than the single cost algorithm.
Hybrid Swarm Intelligence Energy Efficient Clustered Routing Algorithm for Wireless Sensor Networks
Directory of Open Access Journals (Sweden)
Rajeev Kumar
2016-01-01
Full Text Available Currently, wireless sensor networks (WSNs are used in many applications, namely, environment monitoring, disaster management, industrial automation, and medical electronics. Sensor nodes carry many limitations like low battery life, small memory space, and limited computing capability. To create a wireless sensor network more energy efficient, swarm intelligence technique has been applied to resolve many optimization issues in WSNs. In many existing clustering techniques an artificial bee colony (ABC algorithm is utilized to collect information from the field periodically. Nevertheless, in the event based applications, an ant colony optimization (ACO is a good solution to enhance the network lifespan. In this paper, we combine both algorithms (i.e., ABC and ACO and propose a new hybrid ABCACO algorithm to solve a Nondeterministic Polynomial (NP hard and finite problem of WSNs. ABCACO algorithm is divided into three main parts: (i selection of optimal number of subregions and further subregion parts, (ii cluster head selection using ABC algorithm, and (iii efficient data transmission using ACO algorithm. We use a hierarchical clustering technique for data transmission; the data is transmitted from member nodes to the subcluster heads and then from subcluster heads to the elected cluster heads based on some threshold value. Cluster heads use an ACO algorithm to discover the best route for data transmission to the base station (BS. The proposed approach is very useful in designing the framework for forest fire detection and monitoring. The simulation results show that the ABCACO algorithm enhances the stability period by 60% and also improves the goodput by 31% against LEACH and WSNCABC, respectively.
Characterizing Deficiencies of Path-Based Routing for Wireless Multi-Hop Networks
2017-05-01
A number of novel techniques for data- dissemination are being considered, such as efficient flooding [39, 40] or opportunistic routing [41... route data across. This technique for routing in wireless networks is an extension of those initially developed for wired networks. In this paper, we...a route to another user only when it has data destined for that user. To find a route , a control packet is flooded across the network that identifies
Hu, Yifan; Ding, Yongsheng; Hao, Kuangrong; Ren, Lihong; Han, Hua
2014-03-01
The growth of mobile handheld devices promotes sink mobility in an increasing number of wireless sensor networks (WSNs) applications. The movement of the sink may lead to the breakage of existing routes of WSNs, thus the routing recovery problem is a critical challenge. In order to maintain the available route from each source node to the sink, we propose an immune orthogonal learning particle swarm optimisation algorithm (IOLPSOA) to provide fast routing recovery from path failure due to the sink movement, and construct the efficient alternative path to repair the route. Due to its efficient bio-heuristic routing recovery mechanism in the algorithm, the orthogonal learning strategy can guide particles to fly on better directions by constructing a much promising and efficient exemplar, and the immune mechanism can maintain the diversity of the particles. We discuss the implementation of the IOLPSOA-based routing protocol and present the performance evaluation through several simulation experiments. The results demonstrate that the IOLPSOA-based protocol outperforms the other three protocols, which can efficiently repair the routing topology changed by the sink movement, reduce the communication overhead and prolong the lifetime of WSNs with mobile sink.
A Survey on Position-Based Routing Algorithms in Wireless Sensor Networks
Directory of Open Access Journals (Sweden)
Lin Ya-Ping
2009-02-01
Full Text Available Wireless sensor networks (WSN have attracted much attention in recent years for its unique characteristics and wide use in many different applications. Routing protocol is one of key technologies in WSN. In this paper, the position-based routing protocols are surveyed and classified into four categories: flooding-based, curve-based, grid-based and ant algorithm-based intelligent. To each category, the main contribution of related routing protocols is shown including the relationship among the routing protocols. The different routing algorithms in the same category and the different categories are compared based on popular metrics. Moreover, some open research directions in WSN are also discussed.
New dynamic routing algorithm based on MANET in LEO/MEO satellite network
Institute of Scientific and Technical Information of China (English)
LI Zhe; LI Dong-ni; WANG Guang-xing
2006-01-01
The features of low earth orbit/medium earth orbit (LEO/MEO) satellite networks routing algorithm based on inter-satellite link are analyzed and the similarities between satellite networks and mobile Ad Hoc network (MANET) are pointed out.The similar parts in MANET routing protocol are used in the satellite network for reference.A new dynamic routing algorithm based on MANET in LEO/MEO satellite networks,which fits for the LEO/MEO satellite communication system,is proposed.At the same time,the model of the algorithm is simulated and features are analyzed.It is shown that the algorithm has strong adaptability.It can give the network high autonomy,perfect function,low system overhead and great compatibility.
Identifying vital edges in Chinese air route network via memetic algorithm
Du, Wen-Bo; Yan, Gang; Lordan, Oriol; Cao, Xian-Bin
2016-01-01
Due to its rapid development in the past decade, air transportation system has attracted considerable research attention from diverse communities. While most of the previous studies focused on airline networks, here we systematically explore the robustness of the Chinese air route network, and identify the vital edges which form the backbone of Chinese air transportation system. Specifically, we employ a memetic algorithm to minimize the network robustness after removing certain edges hence the solution of this model is the set of vital edges. Counterintuitively, our results show that the most vital edges are not necessarily the edges of highest topological importance, for which we provide an extensive explanation from the microscope of view. Our findings also offer new insights to understanding and optimizing other real-world network systems.
Identifying vital edges in Chinese air route network via memetic algorithm
Directory of Open Access Journals (Sweden)
Wenbo Du
2017-02-01
Full Text Available Due to rapid development in the past decade, air transportation system has attracted considerable research attention from diverse communities. While most of the previous studies focused on airline networks, here we systematically explore the robustness of the Chinese air route network, and identify the vital edges which form the backbone of Chinese air transportation system. Specifically, we employ a memetic algorithm to minimize the network robustness after removing certain edges, and hence the solution of this model is the set of vital edges. Counterintuitively, our results show that the most vital edges are not necessarily the edges of the highest topological importance, for which we provide an extensive explanation from the microscope view. Our findings also offer new insights to understanding and optimizing other real-world network systems.
Institute of Scientific and Technical Information of China (English)
Wang Ke; Wang Qianping; Jiang Dong; Xu Qin
2011-01-01
Deployment of nodes based on K-barrier coverage in an underground wireless sensor network is described.The network has automatic routing recovery by using a basic information table (BIT) for each node.An RSSI positioning algorithm based on a path loss model in the coal mine is used to calculate the path loss in real time within the actual lane way environment.Simulation results show that the packet loss can be controlled to less than 15％ by the routing recovery algorithm under special recovery circumstances.The location precision is within 5 m,which greatly enhances performance compared to traditional frequency location systems.This approach can meet the needs for accurate location underground.
Immune Algorithm for Solving the Optimization Problems of Computer Communication Networks
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
The basic problem in optimizing communication networks is to assign a proper circuit for each origindestination pair in networks so as to minimize the average network delay, and the network optimal route selection model is a multi-constrained 0-1 nonlinear programming problem. In this paper, a new stochastic optimization algorithm, Immune Algorithm, is applied to solve the optimization problem in communication networks. And the backbone network vBNS is chosen to illustrate the technique of evaluating delay in a virtual network. At last, IA is compared with the optimization method in communication networks based on Genetic Algorithm, and the result shows that IA is better than GA in global optimum finding.
A Multi-QoS Constraints Based Routing Algorithm for IP and ATM Networks%一种IP与ATM网络基于多服务质量约束的路由算法
Institute of Scientific and Technical Information of China (English)
邓亚平; 吴慧莲
2001-01-01
In this paper we introduce a routing algorithm for commuication networks with multiple QoS metrics. This algorithm can be used for QoS-based route computaion for ATM PNNI and Internet protocols such as QoS OSPF. Acommunication network containing links with multiple QoS metrics is modeled as a graph with multiple weights associated with its edges. This method takes a metric(e. g. cost)as the optmization target and another metric(e. g. delay)as a constraint. This algorithm is guaranteed to find a nearly optimal path satisfying the given comstraint if such a path exists. The algorithm is very efficient and its computational complexity is O(n2).
Dessing, D.; Vries, S.I. (Sanne); Hegeman, G.; Mechelen, W. van; Pierik, F.H.
2016-01-01
Background: The purpose of this study is to increase our understanding of environmental correlates that are associated with route choice during active transportation to school (ATS) by comparing characteristics of actual walking and cycling routes between home and school with the shortest possible r
Enhanced Contact Graph Routing (ECGR) MACHETE Simulation Model
Segui, John S.; Jennings, Esther H.; Clare, Loren P.
2013-01-01
Contact Graph Routing (CGR) for Delay/Disruption Tolerant Networking (DTN) space-based networks makes use of the predictable nature of node contacts to make real-time routing decisions given unpredictable traffic patterns. The contact graph will have been disseminated to all nodes before the start of route computation. CGR was designed for space-based networking environments where future contact plans are known or are independently computable (e.g., using known orbital dynamics). For each data item (known as a bundle in DTN), a node independently performs route selection by examining possible paths to the destination. Route computation could conceivably run thousands of times a second, so computational load is important. This work refers to the simulation software model of Enhanced Contact Graph Routing (ECGR) for DTN Bundle Protocol in JPL's MACHETE simulation tool. The simulation model was used for performance analysis of CGR and led to several performance enhancements. The simulation model was used to demonstrate the improvements of ECGR over CGR as well as other routing methods in space network scenarios. ECGR moved to using earliest arrival time because it is a global monotonically increasing metric that guarantees the safety properties needed for the solution's correctness since route re-computation occurs at each node to accommodate unpredicted changes (e.g., traffic pattern, link quality). Furthermore, using earliest arrival time enabled the use of the standard Dijkstra algorithm for path selection. The Dijkstra algorithm for path selection has a well-known inexpensive computational cost. These enhancements have been integrated into the open source CGR implementation. The ECGR model is also useful for route metric experimentation and comparisons with other DTN routing protocols particularly when combined with MACHETE's space networking models and Delay Tolerant Link State Routing (DTLSR) model.
A Flow-Partitioned Unequal Clustering Routing Algorithm for Wireless Sensor Networks
Jian Peng; Xiaohai Chen; Tang Liu
2014-01-01
Energy efficiency and energy balance are two important issues for wireless sensor networks. In previous clustering routing algorithms, multihop transmission, sleep scheduling, and unequal clustering are always used to improve energy efficiency and energy balance. In these algorithms, only the cluster heads share the burden of data forwarding in each round. In this paper, we propose a flow-partitioned unequal clustering routing (FPUC) algorithm to achieve better energy efficiency and energy ba...
Automatic theory generation from analyst text files using coherence networks
Shaffer, Steven C.
2014-05-01
This paper describes a three-phase process of extracting knowledge from analyst textual reports. Phase 1 involves performing natural language processing on the source text to extract subject-predicate-object triples. In phase 2, these triples are then fed into a coherence network analysis process, using a genetic algorithm optimization. Finally, the highest-value sub networks are processed into a semantic network graph for display. Initial work on a well- known data set (a Wikipedia article on Abraham Lincoln) has shown excellent results without any specific tuning. Next, we ran the process on the SYNthetic Counter-INsurgency (SYNCOIN) data set, developed at Penn State, yielding interesting and potentially useful results.
Genetic algorithm for neural networks optimization
Setyawati, Bina R.; Creese, Robert C.; Sahirman, Sidharta
2004-11-01
This paper examines the forecasting performance of multi-layer feed forward neural networks in modeling a particular foreign exchange rates, i.e. Japanese Yen/US Dollar. The effects of two learning methods, Back Propagation and Genetic Algorithm, in which the neural network topology and other parameters fixed, were investigated. The early results indicate that the application of this hybrid system seems to be well suited for the forecasting of foreign exchange rates. The Neural Networks and Genetic Algorithm were programmed using MATLAB«.
Wireless network cooperative routing algorithm based on location information%基于位置信息的无线网络协作路由算法
Institute of Scientific and Technical Information of China (English)
周雷; 苏红; 唐昊; 韩江洪
2015-01-01
Lifetime is one of the important performance parameter for energy-constrained wireless network, and how to extend the lifetime is a critical issue in practical applications of wireless network .Saving energy or optimizing the transmission power is one of the most common methods.For direct and cooperative transmission link, a lifetime maxi-mizing cooperative routing algorithm is proposed based on node’s location information, in which cooperative commu-nication is associated with routing mechanism.While guaranteeing the outage rate at a certain level, nonlinear pro-gramming problem is specified to obtain the optimal transmission power.Then, the link costs formula is given, which is constructed by representing transmission energy with optimal transmission power, receiving energy and node’s re-sidual energy.On the basis of the Dijkstra’s shortest path, the link costs formula is used to construct the route from source node to destination node.The simulation results show that this algorithm can reduce the transmission power and save energy consumption of nodes to extend network lifetime effectively.%网络生命周期是评价能量受限无线网络性能的重要指标之一，如何有效延长网络生命周期是影响该类无线网络实际应用的重要问题，优化发射功率或节约能耗是比较常见的解决方法之一。针对直接和协作2种传输链路，将协作通信技术与路由机制相结合，并基于节点的位置信息，提出一种最大化网络生命周期的协作路由算法。该算法在保证一定中断率的前提下，运用非线性规划方法求解最优发射功率，进而构建由节点发射能耗、接收能耗和剩余能量组成的权值代价公式。然后，基于Dijkstra’ s最短路径，依据权值代价公式建立从源节点到目的节点的协作路由。仿真实验结果表明，该算法可以降低节点的发射功率，减少节点的能量消耗，从而有效的延长网络生命周期。
Route Optimization of Stacker in Automatic Warehouse Based on Genetic Algorithm
Cui Changqing; Wang Yiqiang
2013-01-01
Today, automatic warehouse system gradually replaced manual labor, and played an important role in the production work, especially in the cargo handling work. It was important to research the time-consuming and efficiency of stacker in the automated warehouse system. This paper researched the path of stacker in automated warehouse and calculated the operation time of stacker working path according to actual working condition, and then put forward a route optimization method of stacker based o...
Directory of Open Access Journals (Sweden)
Longxiang Li
Full Text Available Effective assessments of air-pollution exposure depend on the ability to accurately predict pollutant concentrations at unmonitored locations, which can be achieved through spatial interpolation. However, most interpolation approaches currently in use are based on the Euclidean distance, which cannot account for the complex nonlinear features displayed by air-pollution distributions in the wind-field. In this study, an interpolation method based on the shortest path distance is developed to characterize the impact of complex urban wind-field on the distribution of the particulate matter concentration. In this method, the wind-field is incorporated by first interpolating the observed wind-field from a meteorological-station network, then using this continuous wind-field to construct a cost surface based on Gaussian dispersion model and calculating the shortest wind-field path distances between locations, and finally replacing the Euclidean distances typically used in Inverse Distance Weighting (IDW with the shortest wind-field path distances. This proposed methodology is used to generate daily and hourly estimation surfaces for the particulate matter concentration in the urban area of Beijing in May 2013. This study demonstrates that wind-fields can be incorporated into an interpolation framework using the shortest wind-field path distance, which leads to a remarkable improvement in both the prediction accuracy and the visual reproduction of the wind-flow effect, both of which are of great importance for the assessment of the effects of pollutants on human health.
Li, Longxiang; Gong, Jianhua; Zhou, Jieping
2014-01-01
Effective assessments of air-pollution exposure depend on the ability to accurately predict pollutant concentrations at unmonitored locations, which can be achieved through spatial interpolation. However, most interpolation approaches currently in use are based on the Euclidean distance, which cannot account for the complex nonlinear features displayed by air-pollution distributions in the wind-field. In this study, an interpolation method based on the shortest path distance is developed to characterize the impact of complex urban wind-field on the distribution of the particulate matter concentration. In this method, the wind-field is incorporated by first interpolating the observed wind-field from a meteorological-station network, then using this continuous wind-field to construct a cost surface based on Gaussian dispersion model and calculating the shortest wind-field path distances between locations, and finally replacing the Euclidean distances typically used in Inverse Distance Weighting (IDW) with the shortest wind-field path distances. This proposed methodology is used to generate daily and hourly estimation surfaces for the particulate matter concentration in the urban area of Beijing in May 2013. This study demonstrates that wind-fields can be incorporated into an interpolation framework using the shortest wind-field path distance, which leads to a remarkable improvement in both the prediction accuracy and the visual reproduction of the win