Sharif Digital Repository

reparedness and emergency procedure be devised in the event of,and prior to,a disaster. One of these disastersoften accompanying byhuge damages, losses and casualtiesisanearthquake. After such a disaster, several governmental and non-governmental organizations usually start relief operations. They commonly pursue their own agendas and use their own facilities and capabilities to help the people affected without pursuing a central plan. These disintegrated behaviors of involved organizations generate contradictory responses and result in either wasted resources or preventing equitable service for all affected people. Due tothe abovefact, this dissertation proposes amodel for improving... 

In recent years, environmental issues has been gaining a great deal of attention in the field of Supply Chain and Supplier Selection. In this research, we first review the current literature and then we try to find the research gap in this area. According to the studies done in this area, no research on supplier selection and optimal order allocation to the suppliers have simultaneously investigated environmental issues, the possibility of storage, green routing of vehicles, purchasing discount, multi-product, and multi-period state in a green supply chain. Therefore, in this study, a multi-objective mathematical model is proposed for supplier selection and optimal order allocation in a... 

One of the most efficient techniques deployed for end-stage renal disease remedy is kidney transplantation, but in this case, we commonly encounter with the problem of gap between the demand of patients and supply of donors. In the majority of models has been proposed until now, either kidney exchange technique in a pool of incompatible pairs or kidney allocation system from deceased donors to waiting list is recommended. In this research, in order to enhance kidney transplantation plans, first, a hybrid conceptual model is proposed. Then, its mathematical model is discussed, in which some of the transplantations are selected from kidney allocation system before injecting to the pool of... 

Graceful and α-valuation are the first labeling methods which was introduce in the late 1960. α-Vaulation of a graph is a special cases of graceful labeling. Despite of the large number of papers published on this subject, in literature, there are few particular techniques to find labeling of graphs. There are still many open problems on this subject ,some of which are well-known in graph theory. In this research, a new mathematical integer model and two constraint programming models are presented for the graph valuation problem in the case of quadratic graphs. Then, a comparision between their results are discussed. The advantages of this model is linearity, independence from graph... 

Transportation services enable economic growth of countries and account as a major part of Gross National Product (GNP) but on the other hand have negative environmental impacts including Greenhouse Gas (GHG) emissions, noise pollution and toxic effects on the ecosystem such as acid rain. The traditional objective of distribution management is usually minimizing economic costs. Given the existing environmental problems, ecological and social effects of transportation should be considered in addition to the conventional economic costs. In this study, a special type of Vehicle Routing Problem (VRP) with a heterogeneous vehicle fleet that in which environmental and traffic considerations taken... 

An α-labeling of a graph is a special case of graceful labeling which was introduced in the late 1960’s. Despite the large number of papers published on this subject in literature, there are few particular techniques to find labeling of graphs. There are still many open problems on this subject, some of which are well-known in Graph Theory. In this thesis, first we present and solve several new mathematical and constraint programming models to find α-labeling of 2-regular graphs. Then, a comparison between their results is discussed. Since, proposed models can only label small size graphs; a tabu search algorithm for labeling the big size 2-regular graphs has been developed. By labeling... 

The occurrence of natural disasters and damages caused by them has greatly impacted humans' lives, which reveals need for us to prepare for confrontation with various disasters. For this purpose, in this research, we are seeking to develop a programming model to reduce damages caused by various disasters. This thesis includes 3 main sections. In first section, some major impacts of disasters are reviewed and studied during the past 118 years and some major lessons are summarized based on statistical data analysis. In second section, a 3-demontional probability density function has been developed to categorize different types of disasters. Furthermore, a scaling system is presented to... 

The following research considers the problem of maximum graph orientation aiming to maximize the total weight of satisfied origin-destination pairs for which the capacity of each edge is limited taking into account the distance and cost. the origin of this problem can be traced to biology literature and protein-protein interaction networks. since the problem is a combinatorial optimization one, in addition to deploying exact methods using mathematical programming, heuristic methods are also investigated. addressing the problem, we propose a two-step procedure. in the first stage are detected the paths between origin-destination pairs and in the second one, the solution to the problem is... 

Today, many organizations and companies are confronted with enormous competition and uncertainty as a result of factors such as political issues, demand fluctuations, technological change, and financial instability As well as increasing business competitiveness, organizations focus on their core activities and lead to the use of outsourcing strategies, These factors are the cause of the formation of the supply chain And the lack of planning and identifying the factors that cause instability in the supply chain leads to its inaccurate performance. World-class organizations today have found that unintegrated production and distribution processes and poor communication with suppliers and... 

In recent years, water issues have been the focus of increasing international concern and debate. Agriculture is not only the world's largest water user in terms of volume, it is also a relatively low-value, low-efficiency water user. These facts are forcing governments and donors to rethink the economic, social and environmental implications of irrigation projects. Population growth, increase in water demand, the extended drought and utilization of too much water for agricultural, have been made water conflicts over water resources. Due to the drought has a significant economic and social impact on the irrigated agricultural sector, Water markets based on transferable water rights developed... 

The water and energy demand increase as the population grows. Increased usage of energy leads to scarcity of available resources and limited absorption capacity of environment. Development of efficient and environmentally compatible energy conversion technologies are conceived as an important option for resolving pressing challenges. Compatibility with environment requires considerable reduction in the share of fossil fuels and efficient utilization of renewable energy sources. Hence, development of high-efficiency solar energy systems is becoming an important challenge in the energy sector. The present study is involved with development an integrated solar system based on the application of... 

This Thesis was an effort to write and quantify an agricultural economic model for Urmia Lake Basin and evaluate the change in water consumption in reaction to a policy change. Aggregated form of the data gathered from 33 counties located in Urmia Lake Basin was used in this research. This data includes the quantity used of each input and their costs, in addition to crop yield and their selling price. In our model, the representative farmer takes into account the price of various inputs, crops and the condition of the farm and its limitations and decides on the profit-maximizing crop pattern. In this model, water is one of the most important inputs and its price and availability, effects the... 

Structural changes in the energy sector, including the need to diversify sources of energy supply, security of supply, energy consumption growth in developing countries, rising oil prices and the exhaustibility of fossil fuel reserves, environmental issues, increased consumption of petrochemical products etc., has led to increased share of natural gas in primary energy supply. Iran has a wide range of options to use natural gas endowment. The present research aims to develop a model for optimal allocation of natural gas to various applications.The gas distribution system is modeled in the present study. Technical onstraints together with economic characteristics are considered in the model.... 

Increase in electricity demands and expansion cost of the power system as well as raising more concerns on environmental issues have led to increasing attraction towards Distributed Generation (DG) application in power systems. DG is generally defined as small generation units, ranging from several KW to several MW, that are installed on the distribution network. In Iran, the energy generated by DG units is purchased by Tavanir or distribution companies through guaranteed fixed-price purchase contract. The contract price imposes substantial effects on the cost and benefit of DG owners as well as those of the distribution company (DisCo). A logical and fair pricing model can provide more... 

Presently, numerous patients die each day while they are awaiting life-saving organ transplant. Despite advances in medicine and technology, and increased awareness of organ donation and transplantation, the gap between supply and demand continues to widen. Therefore, appropriate utilization of donated organs under organ allocation process is vital, and can save several patients’ life. Due to this cause, this study presents a mixed integer multi-period mathematical model to optimize allocation system in an organ transplantation network. The considered network includes donors, hospitals, procurement centers, transplant centers, and patients. The proposed model strives to minimize the overall... 

Increasing of public transit market share in urban transportation is one of the major policies of urban system improvement. Lessening emission and fuel consumption are outstanding achievements of designing and operating effective public transit systems. As rapid transit systems play a major role in urban transit network, feeder bus lines can play as their complementary role in the urban transit scene. Feeder bus network provide a better accessibility and coverage for passengers. In spite of its important role, feeder bus network design is studied in a small number of publications in transit network design. In this study, a mathematical program model is presented to state feeder bus network... 

Cloud computing has brought about many changes in the new business arena. These changes do not only include technological changes, but have penetrated the business models of many companies. For example, in recent years, many companies have migrated from their former systems to cloud computing for reasons such as easy and low-cost access to high-performance hardware and software systems, and to avoid maintenance and repair costs and security costs.Due to the economic conditions in recent years and the high cost of electronic items, the criterion of purchase price has become much more important than in the past among people when buying such goods. Now in the Iranian electronics market,... 

This study offers a framework to manage mass vaccination programs in response to an outbreak in a city. Compared to previous studies, we consider more operational challenges in the vaccination process; for example, transshipment between vaccinations units and availability of second doses. Our objective function is based on the risk of unvaccinated individuals. Therefore, the model aims at favoring those places in the city where the risk of unvaccinated people is high. Using different kinds of vaccines is another factor that our mathematical model includes. Vaccines are categorized into single-dose and double-dose classes. In this regard, the balanced access to different vaccine types is of... 

According to the World Bank, nearly 154 billion cubic meters of gas is flared in the world every year. Iran is known as the third gas flaring country by burning about 11.4 bcm (approximately 8% of the total amount). Flared gas is a rich gas and has a high heating value. Therefore flaring it equals to waste of a valuable source of energy. In addition, serious concerns about its environmental effects due to emission of considerable amounts of CO2, SOx, NOx and other pollutants, makes it necessary to find a solution to reduce gas flaring. There are several ways for flared gas utilization including electricity generation, injecting into oil wells for enhanced oil recovery, gas processing and... 

Continuous increase of energy demand, scarcity of resources, as well as environmental limitations have led to the need to reduce carbon emissions. In this research, an MINLP model based on the mathematical optimization formulation is proposed to reach this issue in a large cogeneration unit. Advantage of the hierarchical approach for carbon management are avoiding individual carbon reduction policies, and embedding emission control techniques in a hierarchical mathematical model that helps us to select the most appropriate policies and prioritize each other. In the carbon management hierarchy, the optimization of the base cycle is done at the first stage. Then, the use of renewable energies...