The asymmetric traveling salesman problem (ATSP) is one of the most fundamental problems in combinatorial optimization. An instance of ATSP is a directed complete graph G = (V,E) with edge weights w : E → N that satisfy the triangle inequality, i. e., w(a, c) ≤ w(a, b) +w(b, c) for all distinct vertices a, b, c ∈ V . The goal is to find a Hamiltonian cycle of minimum weight. The weight of a Ham...

This paper analyzes the elastic net approach (Durbin and Willshaw 1987) to the traveling salesman problem of finding the shortest path through a set of cities. The elastic net approach jointly minimizes the length of an arbitrary path in the plane and the distance between the path points and the cities. The tradeoff between these two require­ ments is controlled by a scale parameter K. A global...

This paper mainly investigates the traveling salesman problem under uncertain environment, in which not all the edge weights are deterministically present, but are present with uncertain variables. As a result, five types optimal route models for the uncertain traveling salesman problem, i.e., expected optimal route, α-optimal route, distribution optimal route, expected approximation optimal ro...

Since the computation of an exact solution is very expensive (under the assumption that P 6= NP ), we are interested in approximate solutions – at least for special cases. Particularly, we look for an Polynomial Time Approximation Scheme (PTAS), i.e., for any fixed error parameter ε > 0, the running time is bounded by a polynomial in n and the costs of the computed tour does not exceed (1+ε) ·O...

The goal of this paper is to develop a Decision Support System (DSS) as a journey planner in complex and large multimodal urban network called Rahyar. Rahyar attempts to identify the most desirable itinerary among all feasible alternatives. The desirability of an itinerary is measured by a disutility function, which is defined as a weighted sum of some criteria. The weight...

Several works indicate the relationship between well-solved combinatorial optimization problems and the core non-emptiness of cooperative games associated with them. In this paper, we consider the core of symmetric traveling salesman games and relate it with well-solved cases of traveling salesman problems. We show that the core of a traveling salesman game in which the distance matrix is a sym...

Crossover operator plays a crucial role in the efficiency of genetic algorithm (GA). Several crossover operators have been proposed for solving the travelling salesman problem (TSP) in the literature. These operators have paid less attention to the characteristics of the traveling salesman problem, and majority of these operators can only generate feasible solutions. In this paper, a crossover ...

the multiple traveling salesman problem (mtsp) involves scheduling m > 1 salesmen to visit a set of n > m nodes so that each node is visited exactly once. the objective is to minimize the total distance traveled by all the salesmen. the mtsp is an example of combinatorial optimization problems, and has a multiplicity of applications, mostly in the areas of routing and scheduling. in this paper,...

In today’s competitive transportation systems, passengers search to find traveling agencies that are able to serve them efficiently considering both traveling time and transportation costs. In this paper, we present a new model for the traveling salesman problem with multiple transporters (TSPMT). In the proposed model, which is more applicable than the traditional versions, each city has diffe...

the traveling salesman problem (tsp) is a well-known combinatorial optimization problem and holds a central place in logistics management. the tsp has received much attention because of its practical applications in industrial problems. many exact, heuristic and metaheuristic approaches have been proposed to solve tsp in recent years. in this paper, a modified ant colony optimization (maco) is ...