Sharif Digital Repository

Nowadays, radiation therapy is one of the most common methods for the cancer treatment. Intensity Modulated Radiation Therapy(IMRT) is a novel technique of radiation therapy that aims to delivere sufficient dose to cancerous tissues while sparing healthy organs. There are various uncertainties in radiation therapy problems, including uncertainty about device setup, device errors, interfraction and intrafraction motions. One of the most important uncertainties is the movement of the tumor during the treatment process(intrafraction motion), as this displacement may cause the cancer tissue to not receive sufficient dose and also to damage the healthy tissue due to a violation of their dose... 

Today, estimating housing prices is very important in different societies. The reason for this growing importance can be considered the role of housing in the economic decisions and policies of any society. This estimate is made using the quantitative and qualitative characteristics of each housing and in different ways. In the past, housing prices were estimated using traditional models, but in the present century, due to easier and more access to the Internet and the development of organizations and businesses in this context, which produces a huge amount of data, the use of traditional models for this purpose is not possible. Therefore, today the use of other methods such as machine... 

Profile Monitoring is a new research topics in the field of statistical process control. In many applications of statistical quality control, sometimes quality of a process or product described by a relationship between a response variable and one or more independent variables.The researchers call this relationship profile. The study seeks to demonstrate that monitoring profiles In addition, the industry can be effective in medical field and improves control of the patient's condition by a doctor. Profiles are usually modeled with a linear regression equation, non-linear or polynomial. finally, the results of this study, using actual data, models and methods to predict and control... 

Markets are becoming more saturated every day and competition between different businesses is increasing. The importance of managing Customer churn in various businesses has become increasingly important because the cost of attracting a new customer is many times greater than retaining an existing customer. With the development of data mining and its increasing expansion and the other side, the increase of stored information related to various organizations and businesses has accelerated the operations of extracting knowledge from data. Today, businesses are moving towards the use of intelligent knowledge extraction systems, of which Customer churn prediction systems are one of the most... 

Nowadays, electrical energy is one of the crucial requirements in human beings’ lives. Since the majority of the world’s energy is met by fossil fuel, the problems such as global warming, the reduction of fossil fuel resources, and unpredictable oscillation of the prices of such fuels have led to a serious crisis for the people of the world. Furthermore, due to the increasing energy demand, the economic development of most countries has a strong correlation with fossil fuel prices. The abovementioned problems have made a lot of countries take alternative policies in terms of generating energy, one of which is using renewable energy resources. This approach is reported to be clean and... 

Recently, data scientists have been paying much attention to sports. Many researches have been done in this field, using data mining and machine learning techniques. The following research aims to predict the results of football matches, which consists of two general approaches. For the first and second approaches, we used video game data and match statistics, respectively. In both approaches, it was tried to predict not only the final result (win, draw, or loss) but also the final goal difference. In the first approach, the home team victory was predicted by 73% accuracy, the draw by 75.4%, and the home team defeat by 73.7%. Nevertheless, in the second approach, the home team victory was... 

Predicting the trend of stock prices is always one of the concerns that stock market analysts and investors face with, which plays a critical role in maximizing the profit from investing in stocks. Past stock price charts, raw material prices, the value of the company's assets, the impact of global markets, the company's products, the organization's development plans, and the same other factors influencing the stock price. News reports are an important source of information for people. Recently, a lot of research has been done to examine the impact of news on stock price trends. This research has two research phases. In the first phase, a text mining method is presented which is using... 

This research examines the importance and implementation of incident management and problem management processes in the field of software development systems. In the fast-paced and dynamic world of software development, incidents and problems can arise that disrupt system performance and impact customer satisfaction. Incident management provides a structured approach to quickly identify, prioritize, and resolve unexpected events, while problem management focuses on identifying root causes and preventing the recurrence of incidents. By addressing the key stages of these processes and their benefits, the research emphasizes the importance of proactive incident resolution, software quality... 

The aim of Emergency Medical Services (EMS) is to provide fast medical care and to transport patients to hospitals at the earliest possible time, so as to reduce injury and fatality rate. Healthcare managers try to improve healthcare systems by reducing the response time to demands. In this thesis, we present mathematical models for the problem of location and relocation of emergency vehicles after the end of their service time or after they have returned to a hospital. We believe that implementing these models can help managers improve the performance of emergency medical services. In the first part of this study, we present a two-level deterministic optimization model considering demand... 

Home health care is one of the newest methods of providing services to patients in developed societies that can respond to the individual lifestyle of the modern age and increase of life expectancy. In this study, a new mathematical model is developed taking into account the flexibility of starting and ending locations of each nurse, according to the specific requirements of each service. In this context, there are some special services that require the picking of materials and health equipment from laboratory or force the nurse to return to laboratory to deliver the specimens and equipment. In the next step, this model is expanded to downgrading aspects by adding the objective of minimizing... 

In summary, this thesis presents a new mathematical model for Home Health Care (HHC) services during the Corona era, which aims to increase the efficiency and quality of services provided by these organizations while ensuring compliance with quarantine protocols. The model is an extension of the VRPPDTW formulation and considers relevant features such as patient classification, caregiver classification, work and break regulations, workload balancing, and multi-depot capabilities. The optimization can be performed with two separate objective functions, one to minimize traveling and idle costs and the other to minimize the total working time of caregivers. The contradictions between two... 

The Multi-Depot Traveling Purchaser Problem under Shared Resources (MDTPPSR) is a new variant of the Traveling Purchaser Problem (TPP). In this problem, each depot can purchase its products using the shared resources of other depots, and vehicles do not have to return to their starting depots. The routing of this problem is a Multi-Trip, Open Vehicle Routing Problem. A tailored integer programming model is formulated to minimize the total purchasers’ costs. Considering the complexity of the model, we have presented a decomposition-based algorithm that breaks down the problem into two phases. In the first phase, tactical decisions regarding supplier selection and the type of collaboration are... 

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... 

In recent years, the cosmetics industry has dramatically grown in e-commerce. In e-commerce platforms, where multiple choices are available, an efficient recommender system is required to sort, order, and effectively transfer relevant content or product information to users. Recommender systems have attracted a lot of attention from retailers because they provide consumers with a personalized shopping experience. With technological advancements, this branch of artificial intelligence exhibits great potential in imaging, analysis, classification, and segmentation. Despite the great potential, the academic articles in this field are limited. Therefore, we conducted research in this context, in... 

The design of an indicator for "quality rate measurement" has been done in many countries around the world, and the quality rate, like other economic indicators, is subject to public judgment. Prerequisite for the formation of this index is the existence of a "comprehensive system" for quality management in the country, in which the duties and powers of various institutions in the issue of quality are specified and responsible for each process. With this excellent system, quality management is done in an integrated manner and quality can be managed efficiently by providing indicators.Quality assessment, in addition to hearing the customer's voice, requires other aspects, including examining... 

Inside an airport, proper Ground Handling Operations (GHO) plays a significant role in timely airplane departures as well as reducing operating costs. These operations consist of numerous processes that follow standard precedence to avoid delays. In this research, the issue of scheduling and allocation of resources for ground operations of the airport has been investigated. For this purpose, using a mathematical programming approach, a two-objective model was proposed to reduce delays and costs. In this model, all ground operation equipment were considered integrally under the standard operational precedence. Moreover, due to the uncertainty factor in the problem under study, an interval... 

People's lives have been affected by the spread of the Covid-19 virus. Due to the high infectivity, governments have screened people, imposed curfews, mandated the use of masks, and so on to reduce the rate of transmission of the disease among people. Meanwhile, infected people are getting treatments: people who are slightly affected are quarantined at home, and those who are heavily affected are treated in hospitals. Hence there is an excessive increase in the hospital workload. On the one hand, this increased workload leads to physical fatigue and, on the other hand, to psychological problems, stress, etc. for the healthcare professionals. Therefore, it is very important to take care of... 

In this thesis we will focus on operating room scheduling considering open strategy and uncertainty in the duration of operations for elective patients. A mixed integer programming model will be proposed having the expected list of patients that are going to be scheduled in the specific time horizon and working hours of doctors with the purpose of maximizing the number of scheduled elective patients in the determined time horizon. We aim to assign each patient to an operating room and a start time regarding operating rooms and surgeons working hours, care units capacity constraints and sequencing constraints. We will define three possible ways for each patient after their operations, naming... 

In today's world, decision-making has become one of the main problems and challenges for managers, despite the conflicting goals and the different scenarios. On the other hand, most existing decision-making methods are not applicable to all issues in different decision-making environments. Therefore, in this study, by presenting a new algorithm, these concerns have been reduced and a new method has been proposed using the concept of stratification recently introduced by Lotfi Zadeh. In the present study, a single system multi stratification and multi-system multi stratification are presented, which provide managers with an easier understanding and analysis of each system so that they can... 

Reliability-centered maintenance (RCM) is one of the main maintenance methodologies that ensures the continuity of the organization's physical assets in order to meet the expectations of its stakeholders. Despite the widespread use of artificial intelligence in maintenance, the use of these tools to improve the RCM implementation process is a new issue. To this end, in this dissertation, using artificial intelligence and soft computing tools, an upgraded RCM system is introduced so that in addition to increasing the accuracy in the implementation of RCM processes, the time and cost required to implement these processes has reduced, and made it possible to record and store the knowledge of...