Hat üzerinde yer seçimi ve dinamik p-medyana genelleştirilmesi.

This study deals with four location problems. The first problem is a brand new location problem on a line and considers the location decisions for depots and quarries in a highway construction project. We develop optimal solution properties of the problem. Using these properties, a dynamic programming algorithm is proposed. The second problem is also a brand new dynamic location problem on a line and locates concrete batching mobile and immobile facilities for a railroad construction project. We develop two mixed integer models to solve the problem. For solving large size problems, we propose a heuristic. Performances of models and the heuristic are tested on randomly generated instances plus a case study data and results are presented. The third problem is a generalization of the second problem to network locations. It is a dynamic version of the well known p-median problem and incorporates mobile facilities. The problem is to locate predetermined number of mobile and immobile facilities over a planning horizon such that sum of facility movement and allocation costs is minimized. Three constructive heuristics and a branch-and-price algorithm are proposed. Performances of these solution procedures are tested on randomly generated instances and results are presented. In the fourth problem we consider a special case of the third problem, allowing only conventional facilities. The algorithm for the third problem is improved so that generating columns and solving a mixed integer model are used repetitively. Performance of the algorithm is tested on randomly generated instances and results are presentedPh.D. - Doctoral Progra

Montaj hattı dengelemesi için bir uyarlanabilir tavlama benzetimi yöntemi ve bir örnek çalışma.

Assembly line balancing problem is one of the most studied NP-Hard problems. NP-Hardness leads us to search for a good solution instead of the optimal solution especially for the big-size problems. Meta-heuristic algorithms are the search methods which are developed to find good solutions to the big-size and combinatorial problems. In this study, it is aimed at solving the multi-objective multi-model assembly line balancing problem of a company. A meta-heuristic algorithm is developed to solve the deterministic assembly line balancing problems. The algorithm developed is tested using the test problems in the literature and the the real life problem of the company as well. The results are analyzed and found to be promising and a solution is proposed for the firm.M.S. - Master of Scienc

INTER-CITY BUS SCHEDULING WITH CENTRAL CITY LOCATION AND TRIP SELECTION

This study considers a real-life inter-city bus scheduling problem that incorporates central city locations and trip selection sub-problems. We seek to determine the size of the bus fleet, the cities to be served, the central cities, and the routes and schedules of buses in the fleet. For this purpose, we developed a number of investment scenarios, and for each scenario, we determined possible trip alternatives between cities and resulting expected profits. We then developed an integer linear programming model and a decomposition-based heuristic, which attempt to solve the problem with the objective of profit maximization. Finally, we compare the performance of both solution approaches in terms of the solution quality and computation time for each of the scenarios. The results show that both methods are capable of achieving satisfactory performance for small and medium-size instances, whereas the heuristic outperforms the exact method significantly on large instances