Sharif Digital Repository

Sports scheduling with its interesting theory and application has been the subject of many research recently. Different problems arise from different league structures with different objectives. Inspired by the structure of soccer leagues in Britain and Netherlands, we study structures in which a different permutation of first half-season rounds is played during second half-season. Some leagues like Premier league in addition to this structure have a special property in which two teams may do not play against each other in the first half-season and play twice in the second half-season. Therefore, we study both structures separately. We present a mathematical model to cover both structures.... 

In season 1, we introduce a mathematical model of the in vivo progression of Alzheimer’s disease with focus on the role of prions in memory impairment. Our model consists of differential equations that describe the dynamic formation of Aβ -amyloid plaques based on the concentrations of Aβ oligomers, PrPC proteins, and the Aβ-×-PrPC complex, which are hypothesized to be responsible for synaptic tox- icity. We prove the well posedness of the model and provided stability results for its unique equilibrium, when the polymerization rate of β-amyloid is constant and also when it is described by a power law. In seson 2, We consider the existence and uniqueness of solutions of an initial-boundary... 

This research considers coordination of pricing and scheduling decisions in a make-to-order environment. We consider a two machine flowshop environment. The objective is to maximize the total net profit, i.e. revenue minus scheduling cost resulting from pricing and scheduling decisions. Prices of orders are set by the manufacturer and demand is a non-increasing function of price. Two mixed integer linear programming models have been developed for the research problem. As the problem is shown to be NP-Hard, a Metaheuristic algorithm is developed which is combination of two tabu search sub algorithms, one for pricing and the other for scheduling. And to evaluate performance, results from... 

As an abrupt epidemic takes place, most healthcare systems are shocked by the surge in the number of susceptible patients’ demands, and decision-makers mostly rely on their frame of reference to deal with the emergency situation as soon as possible. This paper aims to provide a mathematical model as a reliable support for pharmaceutical supply chain planning for the case of the COVID-19 epidemic. Additionally, it aims to integrate cold and non-cold chains is to take into account various pharmaceuticals and vaccines. To propose a model for planning the pharmaceutical supply chains, a mixed-integer linear programming (MILP) model is used for a four-echelon supply chain design. This model aims... 

Prediction and identifying of negative stimulus which affect cost and time of project with analyzing them and conducting appropriate response are implemented in project management risk. In risk management process, planning and conducting the project is done by considering the uncertainty and continuous tracking that requires preventing the occurrence of changes with negative outcome and effective response to risks. True decision making is desirable for project oriented organizations and project managers in order to implementation the verity kind of actions in apposite of risk events and also for project planning in as though least negative outcomes arise.
In current dissertation a... 

The traditional point of view on the scheduling of the healthcare systems, which is in common with the scheduling of other service and manufacturing systems, has contributed to inattention to patients’ psychological status and has given rise to many negative effects not only on them, but also on hospitals. However, this perspective has not been modified yet with respect to the features of healthcare systems, in which patients, rather that machines, are the main entities of the system. In this study, to address this draw back, a new concept, psyche-based optimization, as well as a new scheduling problem, anxiety-based scheduling of operating rooms, as the advent of this concept, have been... 

Human blood is a valuable and scarce product which is only produced by human body. There is no replaceable material for our blood and there has always been a constant need to donors and blood products in societies. Like every other product, blood has to be transfused to patients after it is donated and this process requires a complete and effective blood supply chain. Considering all properties, complexities and uncertainties of a blood supply chain, we need to develop stable methodologies in order to simplify decision making in blood supply chain. In this research, we develop a novel blood distribution system from a regional blood center (RBC) to its nearby hospitals. It helps RBCs plan the... 

The growing amounts of generation of electronic wastes (e-waste) and their increasing environmental impacts require a special optimal waste management strategy. Many different methods have been developed to managing e-waste. To make the best choices according to the conditions of each system, having an adequate knowledge of all methods and comparing them is the most important point. This research aims to design a system for managing e-waste by selecting mobile phones as an example of electronic waste and find the optimal condition of the system to increase economic benefits and reduce environmental impact. Recycling and landfill are selected as the main methods in this project. Four lines... 

This research investigates permutation flow shop scheduling problems with sequence-dependent setup times with minimizing the number of tardy jobs as criterion (Fm|prmu, Sijk|ΣUj). A mixed integer linear programming model has been developed for the research problem. As the problem is shown to be NP-hard, several meta-heuristic algorithms based on tabu search (TS) and imperialist competitive algorithm are developed to heuristically solve the problem. In order to find the best meta-heuristic algorithm, random test problems, ranging in size from small, medium, to large are created and solved by the meta-heuristic algorithms. Then, a detailed statistical experiment, based on split-plot design is... 

Nowadays, with respect to environmental pollution and energy supply, producing gasoline from methanol or syngas is one of the most interesting research subjects. Gasoline production from methanol is a catalytic process that produces high-quality gasoline with minimum unwanted compounds. So this gasoline is a clean fuel and it can be replaced to petroleum gasoline. Because of that, it can be a valuable process in the petrochemical industry. One of the most important aspects of this process is catalyst deactivation with respect to time on stream. Catalyst deactivation is usually caused by poisoning, sintering, blocking pores, and coking. In this research, material and energy balance equations... 

The current study was attributed to uranium uptake by Varion-AP resin from Saghand, Iran Uranium Mine, ore leach liquor. A suitable high-efficiency system was designed for continuous ion exchange at the bench scale and the uranium uptake parameters were optimized. In this system, 1 reactors was used with a volume of 3 liters in stage with the same height difference. A leach liquor containing uranium with a concentration of between 200 and 300 mg/l was flowed from the feed storage by gravity between reactor 1 to 10 at a flow rate of 30 lit/h and Varion-AP resin was transferred in counter-current flow from stage 10 to 1 by a pneumatic pump. The output of each reactor had a screener that... 

The most important sources in container terminals are berth and quay cranes. The main purpose in the container terminals is reducing delay times of vessels. This will be obtained with planning of terminal sources. This research addresses simultaneous berth and quay crane scheduling problem. A mixed integer linear mathematical model is proposed to minimize sum of completion time of vessels. Since the proposed research problem is NP-hard, two methahuristic algorithms based on Tabu Search (TS) and Particle Swarm Optimization (PSO) are presented to heuristically solve the problem. After parameter tuning, PSO and TS algorithms are compared with experimental design methods. The results indicate... 

This project investigates the simulation of osteochondral defect repair using cell therapy. The osteochondral defect is a common defect among people, where accident, age, and osteoporosis are the main causes of this defect. There are many treatment methods in clinics, which include the using bone allografts, drug treatments, and cell therapy. Cell therapy has been used in this project. For this purpose, firstly, the mathematical equations of the system are written and then the system is simulated using Python. In these equations, ten variables including chondrocyte cells, chondrocyte hypertrophy, osteoblast, different production matrices, and nutrients are used, which are written... 

Loop heat pipe (LHP) is a two phase heat transfer device that is mostly used in cooling spacecrafts facilities. In this research a novel LHP is studied analytically and its steady state operating characteristics is analyzed in a one dimensional approach with heat transfer and pressure drop correlations. The novel LHP has a new arrangement in evaporator and reservoir configuration in comparison with conventional LHPs, which results in a different energy and fluid flow. In addition, the novel LHP has a new mechanism for acive control of working temperature. In modeling the proposed LHP the fluid and energy flows are first determined, then proper correltaions for calculationg each energy flow... 

Soft computing consists of a set of powerful methods that have been successfully applied to many different application domains, including business, engineering, and bioinformatics. In this research we propose an innovative approach that uses genetic algorithms to mine a set of behavior data output by a biological system in order to determine the kinetic parameters of the system. In our approach, the machine learning method is integrated with the framework of existent biological information in a wiring diagram so that its findings are expressed in a form of system dynamic behavior. An application of the method to the cell division cycle model has shown that the method can discover optimum... 

Polymer membrane fuel cell is a rich source of renewable energy. Two problems of short life and low reliability in fuel cells are the main problems of this system. The difference in partial pressure of hydrogen and oxygen causes serious damage to the fuel cell and inefficiency of the electricity production capacity. On the other hand, the life and optimal performance of the fuel cell depends on the moisture content of the membrane because the membrane needs sufficient moisture to pass ions. Transparent fuel cells can be used to study the water in the fuel cell. With direct imaging of this type of fuel cells, the phenomenon of water creation in the fuel cell can be studied with the help of... 

Transport phenomena i.e. momentum, heat and mass transfer are occurring inside the eye constantly. Any disturbance in each of these could lead to diseases or ocular problems. Konwledge of transport phenomena can help surgeons and specialists to identify problems more easily and cure the problems effectively. Further more, these phenomena have a great impact on drug delivery inside the eye. Therefore deep understanding of them makes investigation of different therapies easy and convenient. Consequently this understanding could lead to choose the best method and route of administration available. A precise model which is in consistence with the real human eye has been developed and the ocular... 

Wound healing is a complex biological process dependent on multiple variables: tissue oxygenation, wound size, contamination, etc. Many of these factors depend on multiple factors themselves. Mechanisms for some interactions between these factors are still unknown. In this resarch we try to simulate and control wound healing process with focusing on remodeling phase by neural networks as an intelligence technique. For these purposes some materials like mathematical modeling, finite elements method, and effect of external forces on the scar tissue are used here  

A major medical revolution that is helping us overcome some of the worst diseases, including cancer, is angiogenesis, which is based on the processes our bodies use to develop blood vessels. Most human cancers have acquired six essential capabilities: self-sufficiency in growth signals, insensitivity to growth-inhibitory signals, programmed cell death escape, unlimited replication potential, persistent angiogenesis, and tissue invasion that can induce metastasis. In other words, the defense mechanism that prevents any of these acquired capabilities must be neutralized before the cells become malignant and invasive tumors. In fact, tumors in the non-vascular growth stage can only grow up to... 

The main purpose of this research is to consider the operational machine cost in the shop floor scheduling, which is not considered in the literature thoroughly. To this end, four types of problems in the parallel machine environment are studied with the objectives of minimizing makespan and total cost. Accordingly, the problems are as type of multi-objective optimization, so we choose the approach of finding Pareto optimal solutions to solve them. In these problems we have considered unrelated parallel machines, uniform parallel machines, and the cases of existence or non-existence of sequence dependent setup times and costs. In order to solve the problems, various approaches, with respect...