Sharif Digital Repository

Iran has one of the lowest rates of female participation in the labor market among countries. In 2015, for every 100 men over 10 years old, only 21 women’s labor force participation was confirmed. This paper attemps to determine factors which cause low participation rate of women, particularly married ones. For this purpose, using structural estimation method, a dynamic discrete choice model was built, and estimated with means of simulated method of moments (SSM). The results indicated that the most important factor for low participation rate of married woman is children cost. Elimination of this cost would increase participation rate of married women about 30 percantage points  

This study investigates the price elasticity of gasoline smuggling demand in Iran. For this purpose, a panel data of monthly gasoline consumption has been used that contains data for 160 regions of distribution for Iran's Oil Production Company between 2005 and 2014. The results of estimating the monthly elasticity of gasoline smuggling demand in each region show a significant impact of the gasoline price differential between Iran and its neighboring countries, as well as the distance of each region with the neighboring countries on the demand. The results of this study show that whenever gasoline prices increase inside the country, the inclination to smuggling has been decreased due to a... 

This research is aimed at analyzing the effects of forming relationships between oil and gas companies and drilling rigs owned by drilling companies. For this purpose, panel data on 13240 contracts signed between 2000-2010 worldwide are used through employing a model with fixed effects and an instrumental variable for day-rate. Results show that repeated interaction between oil and gas companies and drilling rigs, does on one hand increase the number of contracted projects in future contracts, and on the other hand, improves their drilling performance. Moreover, it is seen that such effects are only captured by the first few interactions, and that they subside and vanish after the firms have... 

In this thesis, at first upstream transient error propagation and amplification phenomenon is introduced. Then, the previous methods to attenuate this phenomenon are presented. To overcome this drawback, a new method that is based on feed-forward and off-take disturbance estimation and lost data reconstruction in wireless communication is presented. In this thesis, an estimation of unknown off-take disturbance at the present time is approximated or in fact predicted using the last data. Also, in the presented method, the lost data is reconstructed using two different methods. At the end, the satisfactory performance of the proposed control method is illustrated by many computer simulations  

The paper aims to investigate the importance of firms’ financial constraints for pricing equity in Iran. We study the impact of financial constraints of non-financial firms on their stock returns using a sample of 241 manufacturing firms listed in Tehran Stock Exchange (TSE) for the period of 2007 to 2014. We use a similar index as in Kaplan and Zingales (1997), KZ, to measure financial constraint. We examine whether financial constraint influences stock returns and can improve the explanatory power of the Fama and French three-factor asset pricing model. Our findings indicate that financial constraints can be considered as an important factor affecting asset returns. Cross-sectional... 

The case for boosting the share of children benefiting from early childhood development (ECD) programs is strong, but expenditure has to be well-aimed. Not every program adopted under the name of ECD will provide the positive impacts that currently anchor ECD discussions among policy makers. In this report, we present results from an experimental evaluation of Cash Grant for Child Care program implemented in Sistan & Baluchestan province of Iran as a government subsidized ECD. The program provides monthly grants to ECD centers, as well as in-kind food quota per every child attending the center. At the end of school year, we did not find any significant differences in cognitive and... 

On May 5, 2014, Iran began the Health Transformation Plan in public hospitals to promote vaginal delivery by increasing physician fees and by freeing payment of natural labor. About five month later part of the plan extended to non-public hospitals, and the fee of vaginal delivery increased there as well. These consequent exogenous policies provide an ideal environment to examine how Ob/Gyn physicians and pregnant mothers respond to financial incentives using difference-in-difference identification. We find that after the first reform caesarean rates declined by 4.92 percent in public hospitals without any health deterioration, a significant but modest drop. Our results suggest that in the... 

In spite of developments in microwave mixers, reducing its noise figure is still a designers’ challenge in receiver applications. Due to generating intermodulations and saturating the following stages, the low noise amplifier cannot have a so much gain to decrease the noise of the following stages in a typical receiver. This problem is intensified in special applications because of low dynamic range of low noise amplifiers. Accordingly, the low noise amplifier is replaced sometimes by the mixer. Therefore, the design of a low noise mixer is an important issue in improving the noise performance of a total receiver.To this end, it is required to accurately analyse the nonlinear and noise... 

Gasoline consumption resulting from vehicular traffic is one of the most significant factors influencing the emission levels of pollutants. Since the sold gasoline at fuel stations does not necessarily translate into vehicular traffic, tracing the final consumer becomes challenging. hence, estimating the impact of gasoline consumption on air pollution is accompanied by biased results. Moreover, the COVID-19 outbreak, acting as an exogenous shock, has provided an opportunity to use data such as COVID-19 and intercity travel as instrumental variables, gasoline consumption, and emission levels, between 2018 and 2020, show unbiased estimates of the effect of gasoline consumption on air... 

With the recent developments in power electronics and electrical drives, there is a need for precise position sensors today more than ever. Having high precision and high reliability in harsh environments, resolvers are the most preferred position sensors among other types of prevalent position detectors. In order to control linear machines, which are widely used in different industries, linear resolvers are employed. This project aims to propose a structure for tubular variable reluctance resolvers, formulate an analytical model for and optimize the proposed structure. In addition to having an acceptable precision, the proposed model should be less time-consuming compared with finite... 

Linear motors are mostly used in industrial applications and linear position sensors are one of the main components of their motion-control systems. The most common position sensors are optical encoders and resolvers. The optical encoders are not suitable for use in high temperature and high-vibration environments. In addition, their mechanical installation is difficult. In contrast, the resolvers are capable of generating absolute position signals with high precision, and low cost. Resolvers can be used in the polluted environments with the wide range of frequency, temperature and vibration. Among different linear sensors, linear resolvers are appropriate choice for harsh environments.... 

One of the main challenges of resolver as a position sensor is using at high speeds. Because in a situation where the speed of moving part is close to the frequency of the resolver excitation voltage, the speed-dependent part in the resolver output signals will be significant and cannot be ignored. In this project, the aim is to provide a method to solve the problem of using a variable reluctance linear resolver with a sinusoidal cross section in a wide speed range. This method is based on the hybrid use of AC and DC excitation in such a way that AC excitation is used at low speeds and DC excitation at high speeds. Considering that determining the threshold speed requires a large number of... 

In this reaserch by comparing some of the recent litreture on indentification production Function,we estimate total factor productivity. We focous on parametric methods, especially Blundell and Bond (2000), Ollay and Pakes (1996), Levinsohn and Petrin (2003) and OLS.Using panel data on plant-level of 4-digits isic in Iran from 1380 to 1390. We choose Levinsohn and Petrin (2003) as the most appropriate estimator then we use that estimator for estimating productivity of plants. At the end we investigate the relation between firm size and productivity, also its ownership and productivity