Sharif Digital Repository

Economic aspects of power systems in their new structures, have been the subject of most of new publications in the area of electrical engineering after the era of restructuring. Nowadays, the power generation business is totally market driven in most of countries all around the world and the system operators are responsible for maintaining a high level of system security as well as the economic operation of the power systems. The development of wind power generation has rapidly progressed over the last decade. With the advancement in wind turbine technology, wind energy has become competitive with other fuel-based resources. The fluctuation of wind, however, makes it difficult to optimize the... 

Location-allocation problem is known as one of the classical problems in industrial engineering. The goals of these problems are finding optimal location of facilities and assigning these facilities to service demands from a given set of point. Location-allocation decisions are widespread through all organization in the world concerning private and public businesses. Therefore, in this study, a practical mathematical model is formulated and solved.In this paper we present a new approach for a budgeted constraint capacitated location-allocation problem integrated with cellular layout approach containing cell formation and group scheduling. Main decisions are composed of formation of... 

Designing a rapid transit network which is capable of providing a convenient coverage for passengers is studied in thisdoctoral thesis. First, a mathematical model of rapid transit network design which is a mixed integer program is presented (C_RTND). Objective function of the model is maximization of acceptable transit coverage and the model is capable of considering different rapid transit technologies. Furthermore, for each technology capacity constraint is considered in the model. Second, a heuristic algorithm is developed and used to solve the proposed model. The algorithm consists of 3 main parts: candidate line generation, network evaluation and a search algorithm for selecting a good... 

When increased emissions are combined with a carbon tax or emissions trading system, the result is a supply chain with increased costs attributable to the emission generated on the different parts of supply chain. Most traditional supply chain design models do not take emissions and carbon costs into account. Hence, there is a need to incorporate emission costs into a supply chain optimization model to see how the optimal supply chain configuration may be affected by the additional expenses. This thesis presents a mathematical programming model for the design of green supply chains. The costs of carbon dioxide equivalent emissions were incorporated in the objective function, along with the... 

Considerable developments in demand-side real-time telemetry systems allow ISOs to use demand-side provided reserves in ancillary service markets. Presently, many ISOs designed programs to utilize the reserve provided by demand response resources in their market, and deploy them in emergency conditions. These programs are called ancillary service demand response (ASDR) programs. This thesis presents a stochastic programming model to schedule reserve provided by demand response resources in load buses of system. The demand-side reserve resources are modeled by demand response providers (DRP) which have the responsibility of aggregating and managing responses of customers. The reserve provided... 

Operating rooms has always been considered as one of the most expensive, yet most profitable part of a hospital. Since many units in the hospitals are related to the operating room, improving efficiency in the operating room will result in increased efficiency in other units, so offering proper solutions in this area is very important. Suitable Planning and scheduling has a great impact on increasing the level of service and efficiency of the hospital. in this thesis, a mixed integer programming model for scheduling weekly elective patients in the surgical theater with the objective of maximizing the number of elective patients for the surgery and also the workload of the operating room... 

Facility layout problem (FLP) is one of the classical problems that concern with planning for the placement of facilities. Two dimensional layout problem is one of the special layout problems that involves with the arrangement of facilities in non predefined shape. For solving the FLP, a number of information such as dimensions of facilities, relations between facilities, governing constrains etc., are required. But in the most research works, it has been assumed that the required information is precisely known. In this thesis, we challenge this assumption considering the size (length and width) of facilities as bounded variable parameters. In order to make the problem solvable in the sense... 

Reviewing the literature on air traffic flow management shows that reducing flight delay is one of the main challenges facing air transportation systems. This is due to the high cost of incurring delays. At the first stage, two mixed integer-programming model is presented here that aims to minimize delay cost of air traffic. The first presented model seeks to minimize flights delay costs by choosing an optimal airport configuration and balancing departure and arrival flights and the second presented model solve this problem with the new approach with categorizing the airplane by types and prioritizing them. Numerical examples are solved in CPLEX 12.6 to evaluate models performance. Numeric... 

This study aims to solve weekly Flight Frequency Determination and Aircraft Maintenance Routing Problem (AMRP) simultaneously. The objective function here is to maximize the total net profit of an assumptive airline with predetermined airfare and origin-destination market demand. All the needed constraints regarding AMRP is added to the modified version of original model which proposed by Ghafoori in 2011. On the other hand, while this kind of model is based on travelling salesman problem, the occurrence of sub-tours is inevitable. Thus, the model will be, secondly, restricted with more constraints which help eliminate infeasible solutions. The proposed model, then, is tested for three... 

Recently, the multi-level and multi-facility industrial problem in supply chain management (SCM) has been widely investigated. Supply chain network design (SCND) is one of the most important strategic decisions in supply chain management. The problem is an important management problem in SCM and aggregates the strategic and tactical and operational level of supply chain planning. The supply networks comprise a number of manufacturing sites, a number of warehouses and distribution centers of unknown locations to be selected from a set of potential locations, and finally a number of customer zones at fixed locations. The system is modeled mathematically as a mixed-integer linear programming... 

external radiation therapy is a methods of cancer treatment or improvement of cancer-related complications. various techniques have been developed for external beam radiation therapy. Among which, Intensity Modulated Radiation Therapy (IMRT), due to its ability to adjust the intensity of radiation beams, has a higher capacity to generate appropriate dose distribution based on tumor size and volume. Intensity Modulated Radiation Therapy is one of the most commonly used procedures of delivering radiation to cancerous tissues, with the aim of reaching the prescripted dose in the target volume while minimizing damage to nearby healthy organs. Two decisions are of fundamental importance: to... 

In many regions of Iran, arid and semiarid climate and increase of water consumption, lead water managers to use optimal operating of water resources systems. During periods of drought, when inflows to the reservoir are low, it may not be possible to satisfy the target delivery (planned demand), and shortage occurs. Also, During periods of drought, the underground water resource’s pollution and inordinate consumption of underground water resources, increase density of water pollution. These reasons always appoint water resource planner to develop models for determine optimal surface water resource operating rules. Using of hedging rules that are attended by many researchers in these... 

Real-world decision-making problems usually have several criteria for evaluating the performance of alternatives. On the other hand, mathematical programming is a very practical tool for modeling and solving decision-making problems and multi-objective mathematical programming has high importance among researchers and managers in this field of study. However, the field of multi-objective integer programming is considered a rigorous category. Methods for solving these types of problems can be divided into three different approaches. There are few approaches and methods for solving multi-objective mixed-integer optimization problems in litreture.In this research, an extension of benders... 

Peoples need financial resources to improve their quality of life, and companies need them to progress and increase their comparative advantage. Borrowing is one of the most popular methods of financing. Peer-to-peer lending, also known as "marketplace" or "social" lending, is a novel form of intermediation that expunges the role of financial institutions (like banks) as an intermediary and allows entities (individuals or businesses) to raise loans directly from other entities. This lending platform can provide better quality services to borrowers (by quickly providing a simple loan application process through a transparent and flexible portal) and lenders (by managing their funding and live... 

Cancer is one of the leading causes of death in the world accounting for 7.6 million deaths (around 13% of all deaths) in 2008. Deaths from cancer worldwide are projected to continue rising, with an estimated 13.1 million deaths in 2030 according to WHO. Cancer is a disease caused by normal cells changing so that they grow in an uncontrolled way. There are over 200 different types of cancer because there are over 200 different types of body cells. Various types of treatments are available among them surgery, radiotherapy and chemotherapy are the three major ones. Mathematical models and control theories can be employed to improve the quality of treatment and obtain systematic strategies of... 

A hierarchical production system in make-to-order environment is presented in this thesis. This production system is consisted of three different decision making levels. Maximum acceptance for production within customer specified time interval was done in the first stage, which is called order arriving stage, based on different client criteria, type of demanded product, and production system constraints. A new hierarchical decision making structure for accepting or rejecting arriving orders is proposed in this level. The output of this acceptance level is orders having maximum production system defined criteria, and minimum production cost along with order delivery time with minimum delay is... 

Blood is a very valuable material for the life of human beings and should be transfused to the patient as soon as possible in case of necessity. It is s perishable product and different blood products have different shelf lives. Therefore, it is important to manage properly blood product inventories in hospitals to avoid shortage and outdate as much as possible. In this research, a bi-objective mixed-integer programming model is developed which aims to simultaneously minimize the total cost of the supply chain network and the total environmental impacts of the activities of the supply chain network. Since the nature of the problem is uncertain, a robust possibilistic programming approach is... 

In recent years, having an efficient supply chain has become an important element in the success of organizations. Attention to different aspects of the supply chain can have a significant impact on gaining a competitive advantage in the market. With the development of global markets, designing resilient supply chains has become a critical issue among businesses. The importance of this topic has prompted researchers and decision-makers to develop quantitative and qualitative models to reduce the damages caused by disruptions to supply chain systems. Various factors, including human and natural elements, can jeopardize the efficiency of supply chain systems. Therefore, supply chain systems... 

This research deals with a realistic cyclic three-stage supply chin consisting of one supplier, one manufacturer and one or more retailers, in FMCG environment. Orders from retailers are supposed to iterate over cycles and parallel machines are available to process perishable jobs with given release dates, due dates and deadlines. To start process of he jobs, perishable raw material, supplied by an external supplier, is required. Jobs are subject to post-production shelf life limitation and must be delivered to retailers during the corresponding time window bounded by due dates and deadlines. Both early and tardy jobs are penalized by partial weighted earliness/tardiness functions and the... 

In the present study by subject optimal structure design of a polygeneration process, has been trying to obtain an optimal structure of a simultaneous production of methanol and power with the approach of green design based on economic and environmental criteria, discussed and examined. In fact, a new approach to green design solution removes environmental pollutants, not just the final refinement rather tried from the beginning to the process, which is designed to produce less pollution. This period coincides took the idea that design engineers concluded that in order to achieve an optimum design, putting together the correct process equipment is effective as design of the individual...