The use of Geographic Information Systems has increased considerably since the eighties and nineties. As one of their most demanding applications we can mention shortestpaths search. Several studies about shortest pa...
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The use of Geographic Information Systems has increased considerably since the eighties and nineties. As one of their most demanding applications we can mention shortestpaths search. Several studies about shortestpathsearch show the feasibility of using graphs for this purpose. Dijkstra's algorithm is one of the classic shortest path search algorithms. This algorithm is not well suited for shortestpathsearch in large graphs. This is the reason why various modifications to Dijkstra's algorithm have been proposed by several authors using heuristics to reduce the run time of shortestpathsearch. One of the most used heuristic algorithms is the A* algorithm, the main goal is to reduce the run time by reducing the search space. This article proposes a modification of Dijkstra's shortest path search algorithm in reduced graphs. It shows that the cost of the path found in this work, is equal to the cost of the path found using Dijkstra's algorithm in the original graph. The results of finding the shortestpath, applying the proposed algorithm, Dijkstra's algorithm and A* algorithm, are compared. This comparison shows that, by applying the approach proposed, it is possible to obtain the optimal path in a similar or even in less time than when using heuristic algorithms.
This article proposes a modified ant colony system algorithm for finding the shortestpath with preferred links. Most of the shortest path search algorithms focus on finding the distance or time shortestpaths. Howeve...
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This article proposes a modified ant colony system algorithm for finding the shortestpath with preferred links. Most of the shortest path search algorithms focus on finding the distance or time shortestpaths. However, these shortestpaths may not necessarily be the optimum path for drivers who prefer choosing a less short, yet more reliable or flexible path. Accordingly, a preference-based shortest path search algorithm is proposed that uses the properties of the links in a map, as specified by a set of data provided by the user of the car navigation system. The proposed algorithm is implemented in C and experiments are performed using maps that include 64, 128, 192, and 256 nodes with 118, 242, 362, and 484 links, respectively. The simulation results with various parameter sets confirm that the proposed algorithm is effective for finding the preference-based shortestpath.
In Printed Circuit Board (PCB) drilling machines, the location of the drill holes are fed into the machine and the PCB will be drilled at the corresponding coordinates. Some machines do not choose the optimal route wh...
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In Printed Circuit Board (PCB) drilling machines, the location of the drill holes are fed into the machine and the PCB will be drilled at the corresponding coordinates. Some machines do not choose the optimal route when completing their tasks. Hence, this paper proposes an approach, which is based on the algorithmshortest path search algorithm (SPSA), for finding the optimal route in PCB holes drilling process. In SPSA, when the robotic arm at the initial position, the algorithm calculates the nearest point to the initial position from all points that the wires start or ends with. If the nearest point is a start-of-wire point, it will use SPS algorithm 1. If the nearest point is an end-of-wire point, it will use SPS algorithm 2. This process is repeated until drilling all the lines. Then, the robotic arm will drill all the holes according to the proposed Simulated Annealing algorithm (AS) in order to determine the optimal machining parameters for milling operations. The results of the different optimization algorithms Genetic algorithm (GA) and AS are compared and conclusions are presented. The proposed Computer Numerical Control (CNC) machine consists of a driver, drill, three stepper motors, cables and microcontroller PIC16f877A to control the movement of the machine. The SPSA algorithm optimizes the use of the motors and other mechanical paths involved in the process while reducing total time taken to traverse all the drill holes. This paper also explains the detailed problem of interest and the mathematical formulation of the problem is defined. Experimental result indicates that the proposed SPSA-based approach is capable to efficiently find the optimal route for PCB holes drilling process.
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