Sharif Digital Repository

When heart failure occurred, revascularization to body’s organs and consequently covering the metabolic demands of different sections faces with problem. Chronic heart failure is the first reason of mortality all over the world. Traditional treatment for CHF at end stage is heart transplantation. But some of patients don’t have the opportunity to benefit from heart transplantation because of aging, health conditions and lack of donors. On the other hand, Left Ventricular Assist Devices that are using for supporting a ventricle suffering from failure face with basic chalanges for example, backflow in lower speeds and suction in higher speed. These constrictions necessitate maximum and minimum... 

This study investigates and enumerates instances of conflict of interests in some job positions in Iran’s Ministry of Health, Treatment and Medical Education. To achieve this goal, we interviewed people involved in the health field and reviewed job descriptions as well. By adopting the prevalent definition of conflict of interests regarding the duties, authorities, and responsibilities, instances of conflict of interests has been relatively identified in each position. The results show that the main reasons (determinants) for cases of conflict of interests can fall into three categories. First, duties of positions are in such a way that being a shareholder, CEO, and member of the board of... 

The value added service industry as in emergent and profitable industry has gained mane attentions by corporate owners especially in the segment of telecommunication and information technology. For launching value added services, communication infrastructure must combined with attractive and high quality contents. For this purpose, mobile network operators have collaborated with content providers to launch services, cooperative advertisements and shared the earned revenue. Interaction between operators and content providers has many complex stages that starts before contract assignment and ends at the revenue sharing stage. For analysis this problem, first, we investigated this interactions... 

In the last decade, emergency department (ED) overcrowding has become a national crisis for the US healthcare system. Increasing mortality rates, decreasing quality of care, financial losses due to walkouts, and ambulance diversion are some of the consequences of ED overcrowding. Given the increasing demand in terms of ambulance utilization which we can see an instance of it in the COVID-19 pandemic, being able to allocate service requests to EDs efficiently, becomes a key function of emergency medical services. in this investigation, an algorithm of deep reinforcement learning called deep Q-learning is used to address this problem and to assign ambulances to ED's appropriately. under... 

With the implementation of the targeted subsidy plan in Iran and as a result, the allocation of cash subsidy to individuals, the effect of this policy on labor supply behavior can be studied. In most of the researches, the degree of the effects of implementing such policies on the working behaviors is studied.
In this research, after discussing some proposed models of labor supply and the effects of nonwage income on that, we reviewed the history of implementing such policies and their outcomes in different countries. Then, the possible methods of studying this issue in Iran were discussed. Finally, using a part of the household budget data in years 1389 and 1390, a panel data was... 

In the early 21st century, Iran established its wholesale electricity market as part of the restructuring of the power industry. Currently, the majority of electricity trades occur in this market. The simultaneous production and consumption of electricity, along with constraints for new companies to enter the market, make exercising market power a significant consideration in the economics literature. The market mechanism is based on auctions and is supported by a rich-data environment that allows for monitoring of production firms' behavior. This research measures the exercise of unilateral market power in Iran's wholesale electricity market using three months' worth of data for each year... 

With the advancement of technology, the volume of network traffic has also increased dramatically. The optical network, as the main part of the backbone communication system, plays a significant role in the transmission of network traffic. Due to the limited network resources, an efficient resource allocation in optical networks is required to increase network performance and reduce costs. To solve resource allocation optimization problems, an effective tool is needed to provide a suitable solution in a reasonable time. Resource allocation problems are usually developed on a graph, which is derived from network topology or other properties of the network. As a result, graph-based tools seem to... 

In this research, direct synthesis of dimethyl ether (DME) from CO2 hydrogenation in three phase slurry reactor was investigated. Bifunctional catalysts composed of Cu- ZnO-Al2O3-ZrO2 as hydrogenation component and zeolite Na-Mordenite as dehydration component, with different Al2O3 and ZrO2 contents were synthesized by coprecipitating sedimentation and influences of Al2O3 and ZrO2 on CO2 conversion and DME selectivity were evaluated. Results show, both Al2O3 and ZrO2 enhanced conversion, but Al2O3 markedly increase selectivity of DME. However, when the total contents of Al2O3 and ZrO2 was increased up to 16 wt% , CO2 conversion and DME selectivity remarkably decreased. BET and XRD analyzes... 

In this study, we intend to examine the effect of physicians’ leisure and parents’ preferences on the choice of the date of C-section. According to the literature, the comfort and convenience of the physician is one of the main factors contributing to the fact that less C-sections are scheduled on weekends compared to other days. On the other hand, avoidance of C-section on the 13th of the month as well as increase of C-section on certain special dates has been observed in different counties. In this study, we use national birth data in Iran from 2013 through 2017. During this period, cesarean rate was about 50% nationwide. According to the results, C-section is reduced by 72%, 42% and 12%... 

Producer-level data for Iranian manufacturing firms shows a large amount of dispersion and concentration in producer level sectoral shares, as well as a very strong relashionship between sectoral shares and markups. We Study the pro-competitive gain from trade in the Iran’s manufacturing sector. Domestic firms in Iranian manufacturing sector are protected via tarfiff and non-tariff barriers enforced by the government. In many sections of manufacturing sector, domestic firms feel little competition and charge high markups. The market power of domestic firms could be reduced by the reduction of tariff rate and increase in import share. As a result of foreign competition pressure, they would be... 

The relationship between the environment and human life has long been considered by researchers. Technological growth in the last century, by the intensification of natural resources usage, led to environmental degradation, and thus the importance of recognizing the relationship between human life and the environment has doubled. The present dissertation is organized in three chapters, in each of which we investigate the impacts of a dimension of environmental degradation on human well-being.In the first chapter, we investigate the effect of drought on expenditure and income per capita of Iranian households. To do this, we combine the expenditure and income data of more than 600,000 urban... 

Planning as one of the most important management tasks in all organizations is necessary and essential. Strategic planning is at the top of every organization’s decision-making, and it is important and crucial. Universities like other organizations cannot survive or thrive without a clear strategy. This study has done considering the importance of planning in universities and higher education institutions and discussing one of the challenges in this field. This challenge is analyzing the paradox of top-down planning and collective decision-making and the authority of faculty members in universities. It is an exploration research with the qualitative method and according to a case study of... 

This thesis develops a multi-market equilibrium framework for analyzing retail electricity markets, with a focus on the interaction between the forward and spot markets under conditions of network uncertainty and renewable integration. We explore `the role of retailers’ hedging strategies, forward contract demand, and their impact on market efficiency. By modeling the forward price and the retailer’s optimal forward position under mean-variance preferences, we derive key equilibrium conditions for the spot, forward, and retail markets. Our results show that an increase in uncertainty leads to lower hedge ratios, even in the face of higher price variance. Numerical simulations using Monte... 

The origin of life is one of the fundamental problems of the science, which is not yet answered appositely. The building blocks of life’s molecules, including nucleic acids (DNA and RNA) and proteins, are composed of carbohydrates and amino acids. At the chemical level, these building blocks have definite chirality. This phenomenon is known as biological homochirality. Due to the fact that this phenomenon has taken place in the early stages of life, it is believed that the life’s origin is to a great extent connected to the origin of biological homochirality. Like every other system, at the microscopic level, life’s molecules are composed of atoms which are governed by the lows of quantum... 

The rate of cesarean section delivery in Iran is high and during the past 14 years, leading up to 2014, kept rising. In this regard, decreasing cesarean section rate was targeted through the healthcare reform plan, which was offered by Ministry of Health and Medical Education. This plan kicked off on May4, 2014. One of the most important proceedings of this plan was making natural childbirth to be free in all hospitals, which are under the auspices of the medical universities. According to healthcare utilization models, lower prices of healthcare services, more health centers and more accessibility to them, increase the probability of using health care services. Current study evaluated the... 

In this thesis, consider three important questions in the Iranian Wholesale Electricity Market (IWEM) and answer its. The first one is whether the bidding behavior of the firms in the IWEM has been ex-post optimal? The results of the research show that, on average, the firm’s bidding behavior didn’t optimal in the IWEM, and therefore the bidding strategy of them could be improved. This issue is importance from the regulatory viewpoint in terms of assessing market efficiency and market power of firms, as well as from the firm’s point of view to improve the bidding strategy and increase its profits. The second issue is the assessment of the firm’s ability to exercise unilateral market power by... 

Cryptocurrencies (cryptos), as a new type of money, are considered a medium of exchange, an investment asset, and a hedging tool in today's world. In 2008, bitcoin as the first cryptocurrency was introduced, which has survived through recent years and has gained more and more popularity every day. Cryptos are one of the first applications of blockchain, the technology that many expect to revolutionize the future world in different ways. We aim to investigate what affects the bitcoin price, based on artificial intelligence and, in particular, machine learning. First, we find features impacting bitcoin price via a thorough investigation of the literature. Then, applying machine learning and... 

In this research, we investigated the relationship between the percentage of institutional investors and two components of idiosyncratic volatility. We show a negative relationship between the percentage of institutional investors and the firm-specific volatility in the next month which lasts for six months. Regarding the industry-specific volatility, there is also a negative relationship, but it lasts only for one month