• 대한안전경영과학회지
• /
• 제13권3호
• /
• pp.107-114
• /
• 2011

Traveling salesman problem is to minimize the total cost for a traveling salesman who wants to make a tour given finite number of cities along with the cost of travel between each pair them, visiting each cities exactly once before returning home. Traveling salesman problem is known to be NP-hard, and it needs a lot of computing time to get the optimal solution, so that heuristics are more frequently developed than optimal algorithms. This study suggests a hybrid parallel genetic algorithm(HPGA) for traveling salesman problem The suggested algorithm combines parallel genetic algorithm, nearest neighbor search, and 2-opt. The suggested algorithm has been tested on 7 problems in TSPLIB and compared the results of existing methods(heuristics, meta-heuristics, hybrid, and parallel). Experimental results shows that HPGA could obtain good solution in total travel distance minimization.

• 한국경영과학회지
• /
• 제33권2호
• /
• pp.17-26
• /
• 2008

The traveling salesman problem is to find tours through all cities at minimum cost ; simply visiting the cities only once that a salesman wants to visit. As such, the traveling salesman problem is a NP-complete problem ; an heuristic algorithm is preferred to an exact algorithm. In this paper, we suggest an effective cost relaxation using a candidate arc set which is obtained from a regression function for the traveling salesman problem. The proposed method sufficiently consider the characteristics of cost of arcs compared to existing methods that randomly choose the arcs for relaxation. For test beds, we used 31 instances over 100 cities existing from TSPLIB and randomly generated 100 instances from well-known instance generators. For almost every instances, the proposed method has found efficiently better solutions than the existing method.

• International Journal of Computer Science & Network Security
• /
• 제23권2호
• /
• pp.55-64
• /
• 2023

The travelling salesman problem (TSP) is an important combinatorial optimization problem that is used in several engineering science branches and has drawn interest to several researchers and scientists. In this problem, a salesman from an arbitrary node, called the warehouse, starts moving and returns to the warehouse after visiting n clients, given that each client is visited only once. The objective in this problem is to find the route with the least cost to the salesman. In this study, a meta-based ant colony system algorithm (ACSA) is suggested to find solution to the TSP that does not use local pheromone update. This algorithm uses the global pheromone update and new heuristic information. Further, pheromone evaporation coefficients are used in search space of the problem as diversification. This modification allows the algorithm to escape local optimization points as much as possible. In addition, 3-opt local search is used as an intensification mechanism for more quality. The effectiveness of the suggested algorithm is assessed on a several standard problem instances. The results show the power of the suggested algorithm which could find quality solutions with a small gap, between obtained solution and optimal solution, of 1%. Additionally, the results in contrast with other algorithms show the appropriate quality of competitiveness of our proposed ACSA.

• International Journal of Computer Science & Network Security
• /
• 제23권6호
• /
• pp.193-201
• /
• 2023

In this paper, we consider the maximum scatter traveling salesman problem (MSTSP), a travelling salesman problem (TSP) variant. The problem aims to maximize the minimum length edge in a salesman's tour that travels each city only once in a network. It is a very complicated NP-hard problem, and hence, exact solutions can be found for small sized problems only. For large-sized problems, heuristic algorithms must be applied, and genetic algorithms (GAs) are found to be very successfully to deal with such problems. So, this paper develops a hybrid GA (HGA) for solving the problem. Our proposed HGA uses sequential sampling algorithm along with 2-opt search for initial population generation, sequential constructive crossover, adaptive mutation, randomly selected one of three local search approaches, and the partially mapped crossover along with swap mutation for perturbation procedure to find better quality solution to the MSTSP. Finally, the suggested HGA is compared with a state-of-art algorithm by solving some TSPLIB symmetric instances of many sizes. Our computational experience reveals that the suggested HGA is better. Further, we provide solutions to some asymmetric TSPLIB instances of many sizes.

• Management Science and Financial Engineering
• /
• 제20권1호
• /
• pp.17-19
• /
• 2014

In this paper, we consider an interesting variant of the inverse minimum traveling salesman problem. Given an instance (G, w) of the minimum traveling salesman problem defined on a metric space, we fix a specified Hamiltonian cycle $HC_0$. The task is then to adjust the edge cost vector w to w' so that the new cost vector w' satisfies the triangle inequality condition and $HC_0$ can be returned by the minimum spanning tree algorithm in the TSP-instance defined with w'. The objective is to minimize the total deviation between the original and the new cost vectors with respect to the $L_1$-norm. We call this problem the inverse metric traveling salesman problem against the minimum spanning tree algorithm and show that it is closely related to the inverse metric spanning tree problem.

• 대한산업공학회지
• /
• 제11권2호
• /
• pp.155-163
• /
• 1985

This paper presents a heuristic algorithm for a multidepot aircraft scheduling and crew scheduling with deal-head flights. This algorithm is extended from a Greedy heuristic algorithm for a multi-depot multi-salesman traveling salesman problem. We first transform a given flight schedule into a multi-depot multi-traveling salesman problem, considering aircraft flight policies and crew management constraints. Then we solve this problem by applying a modified Greedy heuristic algorithm.

• 한국콘텐츠학회논문지
• /
• 제20권11호
• /
• pp.636-643
• /
• 2020

차분 진화 알고리즘은 연속적인 문제 공간인 실수 최적화 문제를 해결하기 위해 개발된 메타휴리스틱 기법 중에 하나이다. 본 연구에서는 차분 진화 알고리즘을 불연속적인 문제 공간인 외판원 문제 해결에 사용하기 위하여 차분 진화 알고리즘에 난수 키 표현법을 적용하였다. 차분 진화 알고리즘은 실수 공간을 탐색하고 오름 차순으로 정렬된 해의 인덱스의 순서를 도시 방문 순서로 하여 적합도를 구한다. TSPLIB에서 제공하는 표준 외판원 문제에 적용하여 실험한 결과 제안한 난수 키 표현법 기반 차분 진화 알고리즘이 외판원 문제 해결에 가능성을 가지고 있음을 확인하였다.

• 한국지능시스템학회논문지
• /
• 제16권2호
• /
• pp.222-227
• /
• 2006

현재 막대한 병렬성을 갖는 DNA 컴퓨팅을 이용하여 Traveling Salesman Problem (TSP)를 해결하기 위한 연구가 진행되고 있다. 하지만 기존의 방법은 그래프 문제의 표현에서 DNA의 특성을 고려하지 않아, 실제 생물학적 실험 결과와의 차이가 발생하고 있다. 따라서 DNA의 특성을 반영하고 생물학적 실험 오류를 줄일 수 있는 DNA 서열 생성 알고리즘이 필요하다. 본 논문에서는 DNA 컴퓨팅에 진화 모델의 하나인 DNA 코딩 방법을 적용한 DNA 서열 생성 알고리즘을 제안한다. 제안한 알고리즘은 TSP에 적용하여 기존에 단순 유전자 알고리즘과 비교하였다. 그 결과 제안한 알고리즘은 오류를 최소화한 우수한 서열을 생성하고 생물학적 실험 오류율도 줄일 수 있었다.

• 한국경영과학회:학술대회논문집
• /
• 대한산업공학회/한국경영과학회 2000년도 춘계공동학술대회 논문집
• /
• pp.48-51
• /
• 2000

The traveling salesman problem with precedence relations (TSPPR) is harder than general traveling salesman problem. In this paper we propose an efficient genetic algorithm (GA) to solve the TSPPR. The key concept of the proposed genetic algorithm is a topological sort (TS). The results of numerical experiments show that the proposed GA approach produces an optimal solution for the TSPPR.

• 한국지능시스템학회논문지
• /
• 제14권1호
• /
• pp.105-111
• /
• 2004

Traveling Salesman Problem(TSP)을 해결하기 위해 DNA 컴퓨팅이 사용되고 있다. 그러나 현재의 DNA 컴퓨팅을, TSP에 적용하였을 때, 정점과 정점사이의 가중치를 효율적으로 표현할 수 없다. 본 논문에서는 TSP의 정점과 정점 사이의 가중치를 효율적으로 표현하기 위해 DNA 컴퓨팅 기법에 DNA 코딩방법을 적용한 ACO(Algorithm for Code Optimization)를 제안한다. 우리는 ACO를 TSP에 적용하였고, 그 결과 ACO 는 Adleman의 DNA 컴퓨팅 알고리즘보다 가변길이의 DNA 코드와 간선의 가중치를 효율적으로 표현할 수 있었다. 또한 ACO 는 Adleman의 DNA 컴퓨팅 알고리즘 보다 탐색 시간과 생물학적 오류율을 50% 정도 줄일 수 있었으며, 빠른 시간 내에 최단경로를 탐색할 수 있었다.