Sharif Digital Repository

Inequality and the feeling of injustice governing in the work environment place is one of the important and influential factors on employees'affecting productivity. If Should the employees believe that they are getting lower wages despite having the same productivity as their colleagues, they receive less wage than those co-workers, they might find the firm's behavior unfair and thus, they would loweradjust their performance accordingly. This problem is of great importance, hence the numerous related studies in the literature. This study investigates the effect of inequal unequal payment and promotion on the productivity of the employees by designing and implementing a natural work... 

Fog computing environment consists of several devices which distribute across an arbitrary topology. Each of these devices is capable of carrying out a designated computation simultaneously with other devices. One of the common ways of describing a computation is through the usage of workflows. Workflow is a flexible and formal way of modeling tasks and their requirements for execution. A workflow is essentially a DAG. Therefore, it can model the data dependency between tasks quite accurately. The complex structure of a workflow in conjunction with the homogenous nature of devices in a fog environment makes it difficult to find a resource management algorithm to minimize execution time, used... 

This project focuses on the design of fuel drop tanks for airplanes that add minimal drag and positive lift to the flying object. This will obviously effect the stability and dynamic performance of the airplane. To reduce adverse dynamic effects the tank was divided to several segment with a special emptying sequence. The add-on tank has to have no interference with the object existing systems and require minimum structural changes in the object. Several designs were proposed and the one gaining highest marks was selected. The flow field and the dynamic behavior of combined vehicle and drop tanks were studied using FE simulations. The result shows that adding a drop tank with optimized... 

This study investigates consumers’ response to changing the household electricity meter from single stroke case to three stroke case. Existence of different prices in different hours during the day is the advantage of three stroke electricity meters compared to single stroke ones. Electricity bill data of 19,742 subscribers, in Tehran Interior Region 2, during the period 1387 to 1393, has been used to evaluate this policy. Subscribers who always use only single stroke electricity meters or three stroke ones are considered as the control group; and subscribers who have experienced electricity meter change during the period are considered as the experimental group. Changing electricity meters... 

In this paper we determine “Tax Incidence” of value added tax (VAT). Incidence Tax represents tax burden that is imposed to each tax-payers: consumers or producers. Value added tax was first implemented in Iran in Mehr 1387. Providing a natural experiment condition, it made it possible to measure tax incidence by using difference-in-difference method. Therefore, data of monthly consumer price index of 23 tax-exempt commodities, and 23 taxable commodities, have been used from Farvardin 1384 till Esfand 1393. According to the results, from 1387 to 1390, no tax incidence regarding value added tax was found. It seems, in the first years of implementation, it is the result of its resemblance with... 

Export subsidy is one of the important issues among the various trade policies in developing countries. For more than a century, various effects of export subsidies have been studied in literature and different results have been presented. In this study, the effect of export subsidy of several agricultural products on their weight and export price has been investigated. In 2015 and 2016, respectively, potatoes and five groups of dairy products were subject to cash subsidies. The results of the research show that the growth of potato’s weight has been affected by the subsidy and has increased. Also, according to the results, the effects of the decrease in export price growth can be seen, and... 

Traffic accidents are one of the main causes of death in Iran. Between 2005 to 2019, 20,000 people were killed and 300,000 were injured on average annually. About 65 percent of all traffic fatalities over the past seven years has been on intercity roads. Finding patterns of accidents on specific days, such as holidays, would help the planners prevent traffic accidents. In this study, using police accident data, traffic counts of Road Maintenance and Transportation Organization, and meteorological data of Iran Meteorological Organization during 2011 to 2018, we study the effect of official holidays, and the days before, after and between two holidays on the rate and severity of road accidents... 

The government in special schools tries to offer a higher quality of education than public schools, and get less tuition than private schools. If the achievements of these schools are positive, it can be expanded as a supportive policy for low-income families in order to raise the educational skills of deprived students. This study conducted on the basis of data from an internet-based survey, in which 130,000 volunteers, which were enrolled in the National university entrance examinations in 1389, answered the questionnaire. By using the propensity score matching method, assumed that the unobservable variables for the two groups, one is enrolled in a special school and the other is enrolled... 

Destruction of green lands, especially forests, is one of the most common forms of environmental degradation. Meanwhile, political institutions can play an important role in protecting or destroying the environment, especially forests. The creation of town and village councils as a change in political institutions and decentralization can have an impact on the environment. Land use change, implementation of development projects and the task of overseeing the implementation of environmental protection laws are among the duties and powers of councils that affect the coverage of various areas. At different eras, town and village councils’ elections have been annulled or dissolved in a... 

The Iran-Iraq war between 1980 to 1988 involved Iran's western borders and inflicted heavy casualties. This war was also spread to the central provinces of Iran in several periods as a result of Iraqi missile attacks, known as the War of Cities. The attacks were mainly intended to intimidate people, leaving relatively few deaths and injuries. In this study, we seek to estimate part of the hidden and long run impacts of these attacks. Using a two-percent sample of Iran’s 1990 census and the information of the location and timing of missile attacks, and by incorporating the difference in difference method, we estimate the causal impact of missile attacks on the years of education of those who... 

Due to the prominence of the evaluation of the consequences of rising temperatures, this paper examines the effects of temperature variation on mortality across different demographic groups in Iran. I use a rich weekly data set from 2009 to 2017 across different demographic groups to understand the potential health impacts of climate change in a developing country. Using several fixed effect regressions, I discover that for an additional day with a mean temperature over 25°C, mortality rate increases by 2.56% relative to the effects of an extra day in 0-5 °C, in the weekly temperature exposure horizon. I test for the harvesting effect by comparing the estimates at weekly and monthly... 

Cancer can be defined as a stochastic phenomenon. Thus, the tumor growth can be defined as a stochastic process. A Cancer tumor can be analyzed by its geometric shape. Furthermore, computing fractal dimension of shapes is a useful technique to analyze chaosity and complexity of shapes. This approach can be used to compare results from laboratory with simulated results of a mathematical model. A stochastic model of tumor growth will be presented. And some geometrical properties will be analyzed through computer simulation of the model  

Emphasis on the expansion of education in Iran's development strategy and increasing demand for higher education in the 2000s required the country to develop higher educational institutes. Unprecedented growth of these institutes in the second half of 2000s was so vast that in 2008 all the counties in Iran had at least one institute. These institutes were established even in the smallest counties in order to solve the problem of transportation for its settlers, and on the other hand, developing higher education institutes in larger cities resulted in an increase in the acceptance rate of these institutes and their accessibility for the people. Moreover, lower accessibility to higher... 

The effects of combined task demands on the way muscles are recruited to balance external loads during posture and movement is of great importance in quantitative analysis of upper arm function. Pain and disability of shoulder joint is becoming more important as population spends more often interacting with computers in seated position and carrying repetitive tasks using upper extremities. Shoulder joint that is more dependent on the muscles for its normal function than other joints such as hip due to its small articular surface and large range motion has been used here to study its coordination during isometric exertions. Since, the numbers of tasks that could be performed are enormous. In... 

The economic effects of large dams that were constructed during 1370-1393 in Iran are explored in this thesis and their effects on agriculture and welfare of their own district and downstream districts are analyzed. Ordinary Least Squares (OLS) method is used to investigate these effects and for more accurate results, we control for geographical variables and rainfall. The results of this study show that dam construction leads to higher agricultural yield, production value and irrigated area in the dam’s own district; but it doesn’t affect yield, production and irrigated area of downstream districts. Also dam construction results in planting more water-intensive crops in their own district... 

Openings and development of subway system have occurred since 1998 in Tehran, and 115 stations have been constructed from then until 2019. This could have various effects on urban characteristics and passenger behaviors, which air pollution could be one of the consequences. In this research, we want to investigate it`s effect on Tehran air pollution as well as heterogenous effects on different distances. For this, we use air pollution data of monitoring stations and meteorological data as well as location and construction time of metro stations. We use difference in difference and OLS regressions to estimate these causal effects. We see that air pollution has been decreased 2-3% as a result... 

Considering the fact that human capital is a crucial element in explaining the differences in income per capita and economic growth among countries, this research focuses on the effect of initial endowments of individuals on the process of human capital accumulation. One of the most important questions one can ask in this regard is whether individuals that are born in households with a low level of endowments, cannot develop their level of human capital due to a lack in the ability to obtain the factors required for their educational attainment. To answer this question, and considering the limitations of obtaining educational data, we aim to answer this question using district-level data.... 

Inadequate nutrition is perhaps the most important problem facing the poor. Being hungry lowers productivity and decreases individuals’ income. All of these factors conspire to help the poor stay poor. Raising the income of the poor is one solution for this problem if the elasticity of calorie and macronutrients with respect to income is greater than zero. This study employs both nonparametric and parametric methods to obtain the elasticity of per capita calorie and macronutrients with respect to household per capita expenditure. The case presented is for urban areas of Islamic republic of Iran, 2008-2016. Under each estimation strategy we employ, we find a strongly significant and positive... 

Considering that the agricultural sector is the largest consumer of water in the basin of Lake Urmia, it seems necessary to provide comprehensive methods of water resources management and formulate appropriate policies to increase water productivity in this sector. For this reason, in this research, we examine the effects of creating a water market in the basin of Lake Urmia. For this purpose, models of agricultural economics and positive mathematical programming techniques at the regional level have been used for modeling to analyze the various effects of water market creation. According to the model, the farmer chooses his cultivation pattern according to the price of the crop and the... 

In this paper we seek to find the contribution of groundwater in irrigation agriculture in Iran. We use nationwide panel data of agricultural production in the period of 1993-2013. The results show us differences in productivity of agricultural outputs due to availability of groundwater. Panel data allows us to control regional factors like soil fertility affecting the productivity. We are looking for the main contributors to groundwater usage. Population growth in demand side and groundwater availability in supply side seem to be the most important factors