Browsing by Subject "Logistics."

Filter results by typing the first few letters
Now showing 1 - 5 of 5
  • Thumbnail Image
    ItemOpen Access
    Debris removal during disaster response phase : a case for Turkey
    (2013) Şahin, Halenur
    In this study, a methodology to provide emergency relief supplies to the disaster affected regions is developed. As a result of destructive effects of disasters, debris, which is the ruin and wreckage of the structures, occurs. Proper removal of debris has significant importance since it blocks the roads and prohibits emergency aid teams to access the disaster affected regions. Wrong disaster management, lack of efficiency and delays in debris removal cause disruptions in providing sheltering, nutrition, healthcare and communication services to the disaster victims, and more importantly they result in loss of lives. Due to the importance of a systematic and efficient way of debris removal from the point of improving disaster victims’ life quality and its contributions to transportation of emergency relief materials to the disaster affected regions, the focus of this study is providing emergency relief supplies to the disaster affected regions as soon as possible, by considering unblocking operations of roads through removing the accumulated debris. To come up with a scientific solution methodology to the problem, mathematical models that select the paths in order to transport emergency aid materials in the presence of debris to the pre-determined disaster affected regions are developed. The performances of the models are tested on two distinct data sets from İstanbul. Since it is crucial to act quickly in an emergency case, a constructive and an improvement heuristic are also proposed.
  • Thumbnail Image
    ItemOpen Access
    Determination of shelter locations and evacuation routes for a possible earthquake in the city of Istanbul
    (2012) Kırıkçı, Ceyda
    In this study, the location of disaster response and relief facilities in Istanbul is investigated in view of a possible earthquake. Our objective is to determine and analyze the assignments of demand nodes to shelter nodes. We propose two mathematical models for this purpose. Model 1 is a path based model, in which the possible paths are determined by preprocessing the network data to assign demands to shelters while obeying path capacities. Model 2 is an arc based model that uses the network data directly and creates the paths as a byproduct of the solution. Both of the models ensure that each demand node is served by at least a shelter node in accordance with road and shelter capacities. We examine the effect of the shelter capacity, the number of shelters, and the road capacities on the results in different cases. In these cases, we find out that the shelter capacity, number of shelters, and road capacities influence the shelters to be opened, the assignment of the demand nodes to these shelters and the used arcs/paths in this assignment.
  • Thumbnail Image
    ItemOpen Access
    Evaluation of Army Corps artillery ammunition supply system via simulation
    (2000) Utku, Durdu Hakan
    Since the use of enhanced technology by the opposing forces, Turkish Armed Forces must adopt new tactics, employ appropriately upgraded delivery equipment to deliver rations, fuel, ammunition, personnel, repair parts to forces in forward areas to be able to react in time. Within the budget limits, the opportunity to explore new tactics and to test and evaluate new logistics material delivery equipment is correspondingly difficult and sometimes impossible. However, by the use of simulation, which is inexpensive, new supply distribution techniques employing different equipment combinations both currently existing and experimental can be tested. In this study, we evaluate the performance of the existing and new systems of army corps artillery ammunition supply systems. The objective is to see whether the systems operate properly and to select the system design.
  • Thumbnail Image
    ItemOpen Access
    A mobile ammunition distribution system design on the battlefield
    (2010) Toyoğlu, Hünkar
    Ammunition has been the most prominent factor in determining the outcome of combat. In this dissertation we study a military logistics problem in which ammunition requirements of the combat units, which are located on the battle- field, are to be satisfied in the right amount when and where they are needed. Our main objective is to provide a decision support tool that can help plan ammunition distribution on the battlefield. We demonstrate through an extensive literature review that the existing models are not capable of handling the specifics of our problem. Hence, we propose a mathematical programming model considering arc-based product-flow with O(n 4 ) decision variables and constraints. The model is a three-layer commodity-flow location routing formulation that distributes multiple products, respects hard time windows, allows demand points to be supplied by more than one vehicle or depot, and locates facilities at two different layers. We then develop a new mathematical programming model with only O(n 3 ) decision variables and constraints by considering node-based product-flow. We derive several valid inequalities to speed up the solution time of our models, illustrate the performance of the models in several realistically sized scenarios, and report encouraging results. Based on these mathematical models we propose two three-phase heuristic methods: a routing-first location-second and a location- first routing-second heuristic. The computational results show that complex real world problems can effectively be solved in reasonable times with the proposed heuristics. Finally, we introduce a dynamic model that designs the distribution system in consecutive time periods for the entire combat duration, and show how the static model can be utilized in dynamic environments.
  • Thumbnail Image
    ItemOpen Access
    Mobile health services for rubal areas in Turkey : a case study for Burdur
    (2013) Kurugöl, Damla
    Currently, healthcare services in urban areas are provided by family health centers coordinated by community health centers. By the application of family physician based system, it is planned to provide mobile healthcare services (MHS) for the people living in the rural areas which have difficulties to reach those health centers in urban areas. In the scope of these ongoing studies, family physicians procure primary health services to the determined villages in between defined time periods. The aim of this project is to schedule a working plan by using family physicians’ mobile healthcare service times effectively. In this context, when the problem was examined, we realized that it has similarities with the periodic vehicle routing problem (PVRP). We proposed several different solution approaches to the PVRP in the context of the mobile healthcare services application that we are interested in. We tested the implementation of our proposed solution approaches using both simulated data and extended data obtained from the villages of Burdur city