Solving Traveling Salesman Problem by Modified Intelligent Water Drop Algorithm

In this paper, a modification to the new problem solving algorithm called “Intelligent Water Drops” or simply IWD algorithm has been proposed. This algorithm is based on the dynamic of river systems and the actions that water drops do in the rivers. Based on the observation on the behavior of natural water drops, artificial water drops are developed which possesses some of the remarkable properties of the natural water drops. These ideas are embedded into the proposed algorithm for solving the Traveling Salesman Problem or the TSP. Here a local Heuristic function has been added to the original IWD algorithm, which measures the undesirability of an IWD to move from one node to another. Also it is suggested that, after a few number of iterations, the soils of all paths of the graph of the given TSP are reinitialized again with the initial soil except the paths of the total-best solution which are given less soil than initial soil. The modified IWD algorithm finds better tours and hopefully escapes local optimums.