地板式三度网孔的性能分析

文章提出了一种新的互连网络模型,它可看作由普通网孔的每个结点删去一条边而产生。文中讨论了这种新式网孔的拓扑性能,并给出了有效的广播算法。     

一种新的交叉立方体最短路径路由算法

Efe提出的交叉立方体(crossed cube)是超立方体(hypercube)的一种变型.交叉立方体的某些性质优于超立方体,比如其直径几乎是超立方体的一半.Efe提出了时间复杂度为O(n2)的交叉立方体最短路径路由算法.Chang等人扩展了Efe的算法,时间复杂度为O(n),它在路由的每一步有更多条边作为最短路径可供寻路选择.但这些边并没有包含全部可进行最短路径路由的边.文中给出了结点各边可进行最短路径路由的充要条件,并在此基础上提出了一种时间复杂度为O(n2)的交叉立方体最短路径路由算法,它在路由的每一步都将所有的最短路径边作为候选边.理论分析和实例表明它可输出任意一条最短路径.     

Dijkstra的一种改进算法

在Dijkstra算法的基础上,该算法使用了一些独特的数据结构(如:前趋表和最短路径表);使用该算法能高效率地求出图中一个顶点到其它各顶点的所有最短路径。用C语言设计了相应程序验证了此算法。     

一种求解最短路径算法

在图论中，一个典型的问题就是路径问题。本文介绍一种求图的最短路径算法，该算法与［１］中的Ｄｉｊｋｓｔｒａ算法、Ｆｏｌｙｄ算法相比，有较大的改进，且直观清晰，略加修改可用来求图的关键路径。     

一种新型最短路径搜索算法的研究

在深入分析Dijksdtra算法的基础上,考虑到图节点之间的拓扑关系以及Dijksdtra算法在计算节点权值时,与已着色节点不相关节点权值存在∞（即该节点不可见）,文章提出了盲目区域最短路径搜索算法,由分析可知计算量大为减少,算法更优。     

单源点最短路径的一种新算法

本文介绍的求单源点最短路径算法是基于图的搜索思想,采用了优先队列技术,符合一般人们寻找最短路径的习惯,比经典方法容易理解,运算速度也较快。     

一种改进的Dijkstra算法的分析及程序实现

Dijkstra算法是求有向图中从某一源点到其余各点最短路径的算法。本文通过对传统的Dijkstra算法进行分析,提出一种改进算法,经理论分析,对于顶点数较多而边数较少的有向稀疏图来说,在求最短路径时能够大大提高算法的运行效率。     

一种改进的Dijkstra算法应用于嵌入式GIS系统

在实践中,Dijkstra算法是处理道路网络的最有效的算法之一.但Dijkstra算法每次都需要扫描节点集合中的所有节点,降低了算法效率.通过对前人的成果和嵌入式系统的性能进行研究和分析后,分两步来提高算法效率:第1步通过数据的预处理缩小算法的搜索范围;第2步为每个节点添加属性值、增加前趋表,以辅助算法快速找到一条最短路径.然后将此算法应用于嵌入式GIS系统中,并使用大量的数据进行测试,结果表明改进的算法明显提高了GIS系统的效率.     

一种优化Dijkstra算法的研究

阐述传统最短路径算法的优缺点,提出对传统寻路问题的优化算法,旨在解决节点较多网络的最短路径问题。比较优化算法与传统算法的搜索效率,以及优化算法之间的异同,测试表明,优化后的算法在效率方面具有明显的优越性。为了验证算法的有效性,最后给出鲁东大学的一个具体应用。     

一种基于仿生算法的传感器网络协议研究

为了降低无线传感器网络的能耗提出了将仿生算法应用于网络路由决策,生成节点之间的最优化路由.给出了仿生算法的基本原理与计算最小路径树的主要步骤.实验结果显示,该算法相对于PVCHI等协议来说,有较好的降低网络节点工作能耗的效果.     

特种军用车辆最短路径算法研究

本文介绍了在战时情况下,能使特种军用车辆顺利、安全、高效通过城市,进入到某一作战区域三种最优路径算法并进行了比较。得出在确定的前提下,A*算法和限定区域算法的运算时间比Dijkstra算法的运算时间短的结论。可通过对此方案的学习研究,进一步提高我部队的作战效率。     

特种军用车辆最短路径算法研究

本文介绍了在战时情况下，能使特种军用车辆顺利、安全、高效通过城市，进入到某一作战区域三种最优路径算法并进行了比较。得出在确定的前提下，A^＊算法扣限定区域算法的运算时间比Dijkstra算法的运算时间短的结论。可通过对此方案的学习研究。进一步提高我部队的作战效率。     

Dijkstra最短路径算法分析与改进

Dijkstra算法是计算最短路径的经典算法,在对该算法分析的基础上,对其进行了优化和改进。其一是对数据存储方式进行了改进,其二是对辅助向量采用堆排序改进。通过优化降低了内存消耗,搜索效率明显提高。     

Approximating Shortest Paths on Weighted Polyhedral Surfaces

One common problem in computational geometry is that of computing shortest paths between two points in a constrained domain. In the context of Geographical Information Systems (GIS), terrains are often modeled as Triangular Irregular Networks (TIN) which are a special class on non-convex polyhedra. It is often necessary to compute shortest paths on the TIN surface which takes into account various weights according to the terrain features. We have developed algorithms to compute approximations of shortest paths on non-convex polyhedra in both the unweighted and weighted domain. The algorithms are based on placing Steiner points along the TIN edges and then creating a graph in which we apply Dijkstra's shortest path algorithm. For two points s and t on a non-convex polyhedral surface P , our analysis bounds the approximate weighted shortest path cost as || Π'(s,t)|| ≤ ||Π(s,t)|| + W |L| , where L denotes the longest edge length of \cal P and W denotes the largest weight of any face of P . The worst case time complexity is bounded by O(n ⁵ ) . An alternate algorithm, based on geometric spanners, is also provided and it ensures that ||Π' (s,t)|| ≤β(||Π(s,t)|| + W|L|) for some fixed constant β >1 , and it runs in O(n ³ log n) worst case time. We also present detailed experimental results which show that the algorithms perform much better in practice and the accuracy is near-optimal. Received April 15, 1998; revised February 15, 1999.     

An Algorithm for Computing a Convex and Simple Path of Bounded Curvature in a Simple Polygon

Abstract. In this paper we study the collision-free path planning problem for a point robot, whose path is of bounded curvature (i.e., constrained to have curvature at most 1), moving in the plane inside an n -sided simple polygon P . Given two points s and t inside P and two directions of travel, one at s and one at t , the problem is to compute a convex and simple path of bounded curvature inside P from s to t consisting of straight-line segments and circular arcs such that (i) the radius of each circular arc is at least 1, (ii) each segment on the path is the tangent between the two consecutive circular arcs on the path, (iii) the given initial direction at s is tangent to the path at s and (iv) the given final direction at t is tangent to the path at t . We propose an O(n ⁴ ) time algorithm for this problem. Using the notion of complete visibility, P is pruned to another polygon P' such that any convex and simple path from s to t inside P also remains inside P' . Then our algorithm constructs the locus of center of a circle of unit radius translating along the boundary of P' and, using this locus, the algorithm constructs a convex and simple path of bounded curvature. Our algorithm is based on the relationship between the Euclidean shortest path, link paths and paths of bounded curvature, and uses several properties derived here on convex and simple paths of bounded curvature. We also show that the path computed by our algorithm can be transformed in O(n) time to a minimal convex and simple path of bounded curvature. Using this transformation and two necessary conditions proposed here for the shortest convex and simple path of bounded curvature, a minimal bounded curvature path is located in O(n ⁴ ) time whose length, except in special situations involving arcs of length greater than π , is at most twice the length of a shortest convex and simple path of bounded curvature.     

一个求解k短路径实用算法

求解k短路径问题在决策支持系统和咨询系统中具有广泛的用途,文章基于Dijkstra算法,给出了一个求解k短路径实用算法,并且分析了算法的时间复杂度和空间复杂度。     

Dijkstra算法在GIS中的优化实现

地理信息系统（GIS）的应用经常涉及最短路径搜索问题。1959年迪杰斯特拉（Dijkstra）提出的Dijkstra算法是最适合网络拓扑中两结点间最短路径搜索的算法之一。本文讨论一般公路交通网络中两结点间的最短路径搜索问题，从核心算法方面对Dijkstra算法进行改进。     

GIS中最短路径搜索算法

文章讨论了一种在GIS环境下的最短路径规划算法,它根据用户给出的起始结点与目标结点以及必经结点序列和避开结点序列在建立的搜索图基础上分段查找最短路径,最后生成满足用户约束条件的最短路径。