Browsing by Subject "Facility Location"

Now showing 1 - 6 of 6

Open Access
Concepts and analysis in facility location under uncertainty : applications to 1-median problem
(2001-08) Demir, Muhittin Hakan
Open Access
Facility location, capacity acquisition and technology selection models for manufacturing strategy planning
(1993) Verter, Vedat
The primary aim of this dissertation research is to contribute to the manufacturing strategy planning process. The firm is perceived as a value chain which can be represented by a production-distribution network. Structural decisions regarding the value chain of a firm are the means to implement the firm’s manufacturing strategy. Thus, development of analytical methods to aid the design of production-distribution sytems constitutes the essence of this study. The differentiating features of the manufacturing strategy planning process within the multinational companies are especially taken into account due to the significance of the globalization in product, factor, and capital markets. A review of the state-of-the-art in production-distribution system design reveals that although the evaluation of strategy alternatives received much attention, the existing analytical methods are lacking the capability to produce manufacturing strategy options. Further, it is shown that the facility location, capacity acquisition, and technology selection decisions have been dealt with separately in the literature. Whereas, the interdependencies among these structural decisions are pronounced within the international context, and hence global manufacturing strategy planning requires their simultaneous optimization. Thus, an analytical method is developed for the integration of the facility location and sizing decisions in producing a single commodity. Then, presence of product-dedicated technology alternatives in acquiring the required production capacity at each facility is incorporated. The analytical method is further extended to the multicommodity problem where product- flexible technology is also available as a technology alternative. Not only the arising models facilitate analysis of the trade-offs associated with the scale and scope economies in capacity/technology acquisition on the basis of alternative facility locations, but they also provide valuable insights regarding the presence of some dominance properties in manufacturing strategy design.
Open Access
The hazardous waste location-routing problem
(2003) Alumur, Sibel
As a result of high industrialization and technology hazardous waste management problem has now become an unavoidable problem of the world. Hazardous waste management involves collection, transportation, treatment and disposal of hazardous wastes. In this thesis, the existing models in the literature are analyzed in terms of applicability. A new multiobjective location-routing model is proposed by combining the applicable aspects from different models. Our model also includes the constraints that reflect certain requirements that have been observed in the literature but could not been incorporated into the models correctly together with the additional constraints that we propose. The aim of the model is to decide on the following questions: where to open treatment centers with which technologies, where to open disposal centers, how to route different types of hazardous wastes to which of the compatible treatment technologies, and how to route waste residues to disposal centers. The model has two objectives of minimizing total cost and minimizing transportation risk. A large scale implementation of the model in the Central Anatolian Region of Turkey is presented.
Open Access
Location of natural disasters search and rescue (SAR) units in sectors
(2003) Uluğ, Murat
Disasters are extreme events that cause great loss of life and property and create severe disruption to human activities. After August 17, 1999 Earthquake, Turkish Armed Forces decided to improve its capabilities on specialized search and rescue missions in order to better cope with large scale natural disasters. After a study conducted at Turkish General Staff Level, it has been decided to form a battalion size search and rescue unit subordinate to special forces command. The battalion is designed to conduct search and rescue perations in cases of flood, earthquake, fire, avalance, chemical and biological disasters. In this study, in addition to the one Natural Disasters SAR unit in Ankara to serve all the population of Turkey, we aim to locate four new SAR facilities for each sector in an optimum way. Our objective is to maximize the number of people who get served by these new units. Naturally, location of new facilities decreases the travel time or travel distance which is very important in natural disasters missions. We build the model, named Basic Model, for the location of new SAR facilities in each sector. By changing constraints and parameter values of the Basic Model, alternative solutions are also presented.
Open Access
Optimization of locating logistic supply coordination centers (LSCC) of Turkish land forces in an earthquake region
(2003) Karaca, Murat
This research aims at finding the optimum location of Military Logistic Supply Coordination Centers (LSCC) that are established by Turkish Land Forces for gathering and distributing the logistic supply materials among citizens in an area of a county damaged by a natural disaster, i.e. earthquake. The problem of finding the optimum locations of LSCCs in disaster regions is modeled as a Maximal Covering Location Problem. Coverage distances are defined based on the capacity of LSCCs that can be located within the area of counties in the damaged regions. Then, candidate points representing potential sites and demand points representing the provinces having high expected damage estimation due to a probable future earthquake that may occur at the vicinity of Ankara Metropolitan area, are defined. In order to set the standarts on various issues regarding the selection of candidate points, additional constraints are defined. Furthermore, weights, determined by considering the earthquake damage hazard expected for each region are assigned to the demand points. The seismicity of Ankara has been investigated by using the statistics of earthquakes equal or larger than Magnitude>4 that occurred in a region with a 140 km radius for the time interval 1900-1997. Two different scenarios are developed for this model. Optimal solutions are found using mathematical programming software LINGO. Finally, the changes in the optimal solutions are analyzed by altering the problem parameters.
Open Access
Terrain visibility optimization problems
(2001) Düger, İbrahim
The Art Gallery Problem is the problem of determining the number of observers necessary to cover an art gallery such that every point is seen by at least one observer. This problem is well known and has a linear time solution for the 2 dimensional case, but little is known about 3-D case. In this thesis, the dominance relationship between vertex guards and point guards is searched and found that a convex polyhedron can be constructed such that it can be covered by some number of point guards which is one third of the number of the vertex guards needed. A new algorithm which tests the visibility of two vertices is constructed for the discrete case. How to compute the visible region of a vertex is shown for the continuous case. Finally, several potential applications of geometric terrain visibility in geographic information systems and coverage problems related with visibility are presented.