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The Bi-objective Capacitated Facility Location-Network Design Problem with Multi-type of Links and Facilities
, M.Sc. Thesis Sharif University of Technology ; Eshghi, Kourosh (Supervisor)
Abstract
One of the primary concerns on many traditional capacitated facility location-network design problems is to consider costs of transportation and establishing of facilities in one single objective function. Considering a single objective in these problems may lead to misleading solutions due to the fact that the transportation costs should be considered in a short-term period of time, and therefore, the higher cost of establishing the facilities may unfairly dilute the role of the transportation cost. In this thesis, we introduce the capacitated facility location-network design problem with two separate objective functions. Moreover, in this problem, it is assumed that for connecting two...
The type e simple assembly line balancing problem: A mixed integer linear programming formulation
, Article Computers and Operations Research ; Volume 64 , 2015 , Pages 168-177 ; 03050548 (ISSN) ; Naderi, B ; Charkhgard, P ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
Although the simple assembly line balancing problem (SALBP) is the topic of many studies, typically they either consider minimizing the number of stations for a given cycle time (called type one), or minimizing the cycle time for a given number of stations (called type two). Rarely, type E of the problem has been considered. In the type E, cycle time and number of stations are both decision variables, and the objective is to maximize the line efficiency. This paper presents a mixed integer linear programming formulation for the type E simple assembly line balancing problem. Moreover, to further strengthen the presented formulation, two enhancement techniques in the form of valid inequalities...
Nondominated nash points: application of biobjective mixed integer programming
, Article 4OR ; Volume 16, Issue 2 , 2018 , Pages 151-171 ; 16194500 (ISSN) ; Savelsbergh, M ; Talebian, M ; Sharif University of Technology
Springer Verlag
2018
Abstract
We study the connection between biobjective mixed integer linear programming and normal form games with two players. We first investigate computing Nash equilibria of normal form games with two players using single-objective mixed integer linear programming. Then, we define the concept of efficient (Pareto optimal) Nash equilibria. This concept is precisely equivalent to the concept of efficient solutions in multi-objective optimization, where the solutions are Nash equilibria. We prove that the set of all points in the payoff (or objective) space of a normal form game with two players corresponding to the utilities of players in an efficient Nash equilibrium, the so-called nondominated Nash...
A linear programming based algorithm to solve a class of optimization problems with a multi-linear objective function and affine constraints
, Article Computers and Operations Research ; Volume 89 , 2018 , Pages 17-30 ; 03050548 (ISSN) ; Savelsbergh, M ; Talebian, M ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
We present a linear programming based algorithm for a class of optimization problems with a multi-linear objective function and affine constraints. This class of optimization problems has only one objective function, but it can also be viewed as a class of multi-objective optimization problems by decomposing its objective function. The proposed algorithm exploits this idea and solves this class of optimization problems from the viewpoint of multi-objective optimization. The algorithm computes an optimal solution when the number of variables in the multi-linear objective function is two, and an approximate solution when the number of variables is greater than two. A computational study...
Nondominated nash points: application of biobjective mixed integer programming
, Article 4OR ; 2017 , Pages 1-21 ; 16194500 (ISSN) ; Savelsbergh, M ; Talebian, M ; Sharif University of Technology
2017
Abstract
We study the connection between biobjective mixed integer linear programming and normal form games with two players. We first investigate computing Nash equilibria of normal form games with two players using single-objective mixed integer linear programming. Then, we define the concept of efficient (Pareto optimal) Nash equilibria. This concept is precisely equivalent to the concept of efficient solutions in multi-objective optimization, where the solutions are Nash equilibria. We prove that the set of all points in the payoff (or objective) space of a normal form game with two players corresponding to the utilities of players in an efficient Nash equilibrium, the so-called nondominated Nash...
Locating Wireless Transmitters by Using Maximal Covering Location Problem and Hata Model
, M.Sc. Thesis Sharif University of Technology ; Akbari Jokar, Mohammad Reza (Supervisor)
Abstract
Locating wireless transmitters is one of the most important issues. That’s why many researchers have worked in this subject recently. Communication Engineers always want to optimize the productivity of wireless transmitters. They prefer to cover a region completely by minimum cost, so they use analytical tools for solving this kind of problems. This type of optimization is very useful for cellular Networks. There is a different kind of wireless services such as high-speed Internet services; their goal is maximizing the covered demand points by minimum cost not covering all of them. Experts use maximal covering location problem for modeling this kind of problems. At first, an extension of one...
Experimental Study of Drying and Calcination of Simulated High-Level Waste (HLW)
, M.Sc. Thesis Sharif University of Technology ; Samadfam, Mohammad (Supervisor) ; Zahakifar, Fazel (Supervisor) ; Zaheri, Parisa (Co-Supervisor)
Abstract
One of the novel methods of stabilization of nuclear waste is the use of vitrification technology. In order to stabilize high level wastes (HLLW) in glass, it is required that the elements are in their oxide form. Therefore, it is necessary to evaporate the waste and turn it into a solid form so that the elements can be converted into oxide form in the calcination furnace. Hence, one of the challenges of stabilization is the optimization of evaporation and calcination conditions. In this research, the parameters affecting evaporation were first investigated. Using laboratory measurements of application: temperature (110 to 180 °C), presence of nitric acid (0.5 to 4 mol/L), ratio of zirconium...
The Study of Effective Parameters on Thorium Extraction by Cyanex 272 in an Emulsion Liquid Membrane System
, M.Sc. Thesis Sharif University of Technology ; Samadfam, Mohammad (Supervisor) ; Zaheri, Parisa (Supervisor) ; Zahakifar, Fazel (Co-Supervisor)
Abstract
This study used the emulsion liquid membrane method to investigate the extraction and separation of thorium from nitrate solution. According to the results obtained from the studies, Cyanex 272 was a suitable option for selectively extracting thorium. For simultaneous extraction and stripping of thorium from dilute aqueous solutions, an emulsion liquid membrane system consisting of Cyanex 272 as an extractant, Span 80 as a surfactant and sulfuric acid solution as a receiving phase (internal phase) was used. Emulsion liquid membrane method has high mass transfer flux due to high surface to volume ratio, which causes high extraction efficiency and fast transfer of thorium ions from its low...
Planar maximal covering location problem with inclined ellipses
, Article Applied Mechanics and Materials, 29 July 2011 through 31 July 2011 ; Volume 110-116 , July , 2012 , Pages 4861-4866 ; 16609336 (ISSN) ; 9783037852620 (ISBN) ; Jokar, M. R. A ; Int. Assoc. Comput. Sci. Inf. Technol. (IACSIT) ; Sharif University of Technology
2012
Abstract
Aximum coverage location problem is considered in this study. Extension of this problem is investigated for situations that coverage areas are elliptical; these ellipses can locate anywhere on the plane with any angle. Mixed integer nonlinear programming (MINLP) is applied for formulation. This problem can be used in many practical situations such as locating wireless transmitter towers. A heuristic algorithm named MCLPEA for solving this problem was designed. This algorithm can produce very good results in efficient running time. Finally, the comparison of the results for this study was carried done
Fabrication Patient-Specific Drill Guide Templates for Cervical Pedicle Screw Placement
, M.Sc. Thesis Sharif University of Technology ; Arjmand, Navid (Supervisor) ; Parnianpour, Mohammad (Supervisor) ; Azimi, Parisa (Co-Supervisor)
Abstract
One of the most common spinal surgeries involves spinal fusion or vertebral fixation, which is used to treat various conditions such as intervertebral disc disease, scoliosis (lateral deviation of the spinal column), fractures, infections, or the presence of tumors in the spinal column. In this surgical procedure, the use of pedicle screws and titanium rods prevents motion and friction between two vertebrae. Screws may enter the vertebrae in the wrong position and angle, causing bone weakening, rupture of nerve roots or blood vessels, weakness or lack of sensation in some parts of the body, spinal cord injury, and in severe cases, paralysis of the patient. For this reason, fusion surgery is...
Investigation of Mass Transfer Coefficients in Lithium Liquid-Liquid Extraction Process in Batch and Continuous Modes (Microchannel)
, M.Sc. Thesis Sharif University of Technology ; Otokesh, Mohammad (Supervisor) ; Amari Allahyari, Sareh (Supervisor) ; Zaheri, Parisa (Co-Supervisor)
Abstract
Lithium is a soft, silvery-white alkali metal that is recognized as the lightest metal and the least dense solid element. The increasing demand for lithium, driven by the global shift towards electrification and sustainable energy solutions, has transformed this material into a crucial resource in the modern economy. Lithium has applications in various industries, including the nuclear industry. 6Li is used for the production of tritium, and 7Li, in the form of 7LiOH, is used to adjust the pH in light water reactors and as an anti-corrosion compound in fission reactors. In this study, the extraction of lithium from the aqueous phase using a Y-shaped microchannel was carried out, and the mass...