Sharif Digital Repository

Location-routing problems are a class of well-known supply chain problems. the purpose of these problems are to locate depots, assign customers to the located depots, and to determine the routes in a way to minimize the costs of the supply chain.In the past two decades, with a rise in environmental problems including air pollution, green location-routing problems have been introduced and studied, problems in which environmental aspects such as air pollution have been considered.In this study, first, we model a two-stage stochastic green location routing problem; this problem includes a certain number of cities that each represent a customer. the locations of the cities are known and each... 

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... 

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... 

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... 

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... 

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... 

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... 

Infectious diseases have always threatened the health of human beings. One of the most important causes of mortality in human societies is infectious diseases. The spread of these diseases in society, even if does not lead to death, can have devastating effects on society. Influenza is one of the infectious diseases that has attracted much attention today. It can be mild or severe and even cause hospitalization and death. Therefore, controlling and preventing the epidemic of this disease is very important. Epidemic models are commonly used to simulate the spread of infectious diseases. In this study to identify the influenza outbreak, a stochastic multigroup SEIR model with the migration... 

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... 

Nowadays, chemotherapy is one of the common ways to treat cancer. Although, chemotherapy is used to kill cancer cells , chemotherapy drugs also target healthy cells and tissues of the body. In practice, it is difficult to strike a balance between injectable doses of drugs and toxicity in the body, and physicians are always looking for an effective treatment plan. One of the most common drugs that physicians use in chemotherapy is cell-cycle-specific drugs. These types of chemotherapy drugs affect only a certain phase of cell cycle and to a certain extent. Since the lifetime of the cancer cells is uncertain, the effective use of these drugs depends on the correct injection time of the drugs... 

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 recent two decades, occurrence of unexpected disruptions, made supply chains more vulnerable and caused huge damages to them. As a result, in recent researches, the concept of supply chain resilience that concentrates on supply chain vulnerability and disruptions has been focused more. In this thesis, a new framework for resilient suppliers characteristics would be presented that can be used for evaluating resilience level of suppliers and resilient supplier selection. By utilizing scenario-based two-stage stochastic approach, a multi-objective mixed integer nonlinear model is proposed for designing a resilient four echelon supply. In the proposed model, the possibility of partial... 

Demand forecasting has always been a concern for business owners as one of the main activities in supply chain management. Unlike the past that forecasting was carried out by means of limited amount of information, today, forecasting is performed using machine learning algorithms and data-driven methods with the advent of new technologies and data explosion. Patterns and trends of demand, customer information and preferences, comments and suggestions, post-consumption feedbacks are some types of data which are used in these approaches. Considering the all mentioned changes, traditional statistical methods and techniques such as time series analysis have bias in predicting these kind of data... 

In this study, a smart grid algorithm based on pricing and by considering a model in the electricity market is presenting, which is focused on reducing the cost of production for the supplier as well as increase the utility for the electricity consumer. The algorithm has been also modeling by considering multiple suppliers. The model has been designing by taking the home subscribers in to account and to increase their social welfare. The difference between the following developing model compared to the other ones, which are presented so far, is the consideration of the competition between suppliers and the real-time pricing conditions. In fact, in this model, the price of electricity has... 

Recommending routes to city taxis in order to improve their performance in finding passengers can reduce traffic, pollution and waiting time for passengers, as well as this, increasing the efficiency of taxis can increase their income. In this study, by analyzing trajectory data obtained from 536 taxis in San Francisco over a period of one month, we generated networks of cells, each of which has time-dependent characteristics such as the probability of finding a passenger, the capacity of each cell, or the amount of demand exists is in the cell and the average speed of passing through that cell. also, the connections between these cells in order to make more use of the experiences of taxi... 

The purpose of the present study is to develop neural network estimation method for hybrid or panel data which have a combination of two cross-sectional and time series structures and because of the features of both structures, their use in different sciences offers many advantages; and the analytical methods for this data structure are also different from other one-dimensional structures, so different and specific regression models are presented for this data structure. However, in the artificial neural network method, modeling the development for this data structure is neglected, so in the present study, using the concepts of panel regression methods and their application to the... 

User-generated data in TripAdvisor.com consists of considerable amount of useful information that can help managers to provide better services to their customers. In this study reviews to all hotels of Tehran, Iran and Auckland, New Zealand on TripAdvisor.com as real data are selected and scraped by Java programming language. In addition, information about hotels (e.g. name of hotel, overall rating, hotel’s class, total reviews, and hotel’s amenities) and information about the reviews and reviewers (e.g. date of review, country of the reviewer, contribution rate, rate to the hotel, text of review, date of stay, trip type, and years in TripAdvisor) are extracted as well. 64 and 190 hotels of... 

Hospital inpatient units are critical resources because of limited space and large construction investment and operating costs. The essential criteria of hospital capacity are the number of hospital beds. Inpatient beds are shared among different types of care units with different arrival rate, length of stays and needs. Hospitals face many challenges and problems in management of inpatient units, especially in advanced societies that have been increasingly faced in demand in medical units and the need for proper use of limited and scarce hospital resources is strongly felt, including existing challenges, lack of balance in the performance of inpatient units. In this project, we investigate... 

Policies affect supply chain management in oil, gas and petrochemical industries. In this study, structural equation modeling was used to evaluate the relationship between variables in AMOS software. The findings also indicated that international policies affect different aspects of supply chain management in the following order: product realization management (coordination), customer delivery management (partnership), planning management (planning) and resource management (implementation). Finally, suggestions were made on how to find financing such as bank loans, prioritizing payments in the light of their criticality, as well as on the creation. This study aimed to investigate the impact... 

Risk management is the systematic application of management policies, procedures and processes related to risk analysis, assessment and control activities. Risk management is the process of documenting the final decisions made and identifying and applying criteria that can be used to bring risk to an acceptable level. Costs have been studied separately as less attention has been paid to the combination of these two factors. In this study, the combined effect of these two factors on projects in the first place and then on construction, operation and transfer projects has been investigated. The statistical population of the present study consists of 250 contractors and employers of...