Transmitters and receivers are the basic elements of wireless networks and are characterized by a number of radio-electrical parameters. A general planning problem consists in establishing suitable values for these parameters so as to optimize some network performance indicator. In this paper we consider a version of the problem called the Power Assignment Problem (PAP), that is the problem of ...

This paper gives approximation algorithms for solving the following motion planning problem: Given a set of polyhedral obstacles and points s and t, find a shortest path from s to t that avoids the obstacles. The paths found by the algorithms are piecewise linear, and the length of a path is the sum of the lengths of the line segments making up the path. Approximation algorithms will be given f...

We focus on obtaining sparse representations of metrics: these are called spanners, and they have been studied extensively both for general and Euclidean metrics. Formally, a t-spanner for a metric M = (V, d) is an undirected graph G = (V,E) such that the distances according to dG (the shortest-path metric of G) are close to the distances in d: i.e., d(u, v) ≤ dG(u, v) ≤ t d(u, v). Clearly, one...

This paper studies the impact of pattern databases for solving shortest path planning problems with limited memory. It contributes a bucket implementation of Dijkstra’s algorithm for the construction of shortest path planning pattern databases and their use in symbolic A* search. For improved efficiency, the paper analyzes the locality for weighted problem graphs and shows that it matches the d...

In this paper, we consider tactical planning for a class of the multi-period vehicle routing problem (MPVRP). This problem involves optimizing daily product collections from several production locations over a given planning horizon. In this context, a single vehicle routing plan for the whole horizon must be prepared, and the seasonal variations in the producers' supplies must be taken into ac...

This paper presents a general approach to find the shortest path for a general moving object with rotation and forwardhackward movement among obstacles of ahitrary shapes. We call the object of finding a shortest path as path planning. By utilizing the cmcept of the critical transition point and adaptive path planning, finding a shortest path problem of car-like vehlcles becomes more practical....

This thesis introduces a new algorithm for quickly answering repetitive least-cost queries between pairs of points on the Earth's surface as represented by digital topographical maps. The algorithm uses a three-step process; preprocessing, geometrically modified Dijkstra search, and postprocessing. The preprocessing step computes and saves highly valuable global information that describes the u...

Simple Subgoal Graphs are constructed from grids by placing subgoals at the corners of obstacles and connecting them. They are analogous to visibility graphs for continuous terrain but have fewer edges and can be used to quickly find shortest paths on grids. The vertices of a Simple Subgoal Graph can be partitioned into different levels to create N-Level Subgoal Graphs, which can be used to fin...

Path planning contributes a very significant role in navigation of a mobile robot. The accuracy of path depends on mapping and localization of an indoor environment. A number of path planning approach are already in applications like A* Algorithms, D* Algorithm (Heuristic Approach), Dijkstra’s Algorithm (Deterministic approach), Cell Decomposition Technique etc. The conventional A* algorithm me...