Distance Weighted Ant System for Solving the Traveling Salesman Problem

• Main Authors: Meng-Chieh Kang, 康孟傑
• Other Authors: Chung-Yu Pan
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/36221882753112255484

碩士 === 東海大學 === 工業工程與經營資訊學系 === 102 === Because modern society have demand on the time and cost as well as the popularity of computers, in order to effectively use time and reduce costs, so makes the real-life problems simply into mathematical models that can be calculated, such as traveling salesman problem (TSP), vehicle routing problem (VRP), quadratic assignment problem (QAP), and so on. TSP is an optimization problem for salesman to obtain the minimum distance, its wide range of applications, such as scheduling, transportation, chemical engineering, electronic engineering and other issues, all can be transformed to TSP. Since the first ant algorithm, Ant System (AS) was developed, there were many scholars devoted to improve ant algorithm. Ant algorithm has been applied to solve many Combinatorial Optimization Problems, such as TSP, VRP, QAP, and so on. This paper present the Distance Weighted Ant System (DWAS), an ant algorithm improved for pheromone evaporation. DWAS differs from other ant algorithms in pheromone evaporation, whose makes evaporation rate along with the length of distance will vary. This paper used three TSP instances from TSPLIB to test, and the TSP instances were eil51, kroA100, d198, afterwards, compared with AS, Ant Colony System (ACS) and MAX-MIN Ant System (MMAS). The compared results show that: on the same number of tour constructions, DWAS only slightly better than AS in d198, the other results are worse; DWAS’s number of tour constructions was double, DWAS are better than AS, but still worse than ACS and MMAS.