Sharif Digital Repository

This research has been surveyed the impact of intermediate skilled and high skilled human labor force on the productivity of manufacturing sectors by the Nelson & Phelps and also Lucas approaches. first model is related to the level of productivity and the second model is related to the growth of it. We has been prepared the needed statistics from the raw figures of iran statistics center. regression analysis has been done on the basis of panel data model by the use of stata software. the results show that not good efficiency to optimize technology factor of Cobb-Douglas model although it shows higher marginal labor productivity of high skilled human labor force. we has proposed some... 

The present research focuses on the simulation of the metallic powder compaction process with the Peridynamics theory. Various methods are exploited to simulate this process in literature. Studying the nonlinear behavior of powders includes different phenomena such as dislocation and grain boundary, making it complicated. However, numerous research has been shaped to consider these phenomena on the micro-scale. There is also another batch of nano-scale studies underway. In this class of simulations, considering atoms as rigid particles, interatomic potentials, and molecular dynamics methods are used. Because of atomic-scale precision, this approach has very high accuracy. The massive... 

Real estate section is an integral part of any economy whose cycles have considerable effects on other different markets. It attracts much attention by various economy agents for different reasons. However, some specific features of the market render it prone to consecutive boom-bust cycles. Some of these features are originated from fundamental traits and especially building process and production technology of housing. Also, taking into account that real estate is considered an important asset; it is vulnerable to another factor which even exacerbates the cycles. This factor -Information cascade- makes cycles more unstable by causing "Herd behavior" which is the subject of study in this... 

Neural field models with delays define a useful framework for modeling macroscopic parts of the cortex involving several populations of neurons. Nonlinear delayed integrodi fferential equations describe the spatio-temporal behavior of these fields. We also present a study of the numerical computation of these solutions in a special case. Another original contribution of ours is the definition of a Lyapunov functional and the result of stability it implies. We illustrate our work on a variety of examples that are relevant to modeling in neuroscience.
 

Commercial banks have got an important role in our lives and every one can mention veriety functions for them. The more benefits can bring the more risks can couse as the old tradeoff between risk and return. One of the important risks that can bring about lots of problem for banking system is liquidity risk. Being not able to respond customers’ liquidity demand is named the liquidity risk. Banks keep some reserve in cental bank to respond other banks’ liquidity demands in payment system. Shortage of this reserve will cause customer and central bank punishments and penalties. Excess reserve on the other hand has opportunity cost. Hence an optimum amount of liquidity resrve must be held in... 

Based on modern finance theory, valuation should not depend on nominal stock prices. However, evidence shows that the nominal price of stocks does matter in the U.S. stock market. In this paper, we examine the effect of nominal share prices on stock returns, using data between 2009 and 2017 form the Tehran Stock Exchange. Our results indicate that there is no significant relationship between nominal price and return on the Tehran Stock Exchange. By controlling for different important variables, the return differential between high price and low price stocks is insignificant and the results are robust to various specifications and tests. Furthermore, by using event study under the market... 

Since the classical continuum theory fails to deal with the problems associated with defects, stress concentrators, and relevant deformation phenomena in solids, alternative approaches that can detect the atomistic nature of materials' fracture are required. The deficiency of the capture the size effect which yields delusively high values for some components of the stress field right on the edge of the stress concentrators, and its weakness in describing the complex interaction between small inhomogeneities, cracks and the like when they are only a few nanometers apart, are among some of the disadvantages of the classical approach. In recent years, however, atomistic methods are emerging to... 

Aluminum Bronzes have many applications in marine environments. These alloys suffer from both hot cracking and cold cracking. In order to overcome the hot cracking and cold cracking, Semisolid Stir Joining method and a proper thermal cycle was used respectively. Effects of temperature, stirring rate, and tool type were investigated in Semisolid Stir joining method. In this method, butt joint design was used in order to place specimens, and the specimens were heated up to specific temperatures (920, 925, 930°C). A stirrer (Cylindrical and Grooved tool) with three rotational speeds (800, 1200, 1600 RPM) was introduced into the stir weld seam. Welded specimens were cooled to the 900°C... 

The low female labor force participation rate in the Iranian labor market relative to the global average and even to countries that do not differ significantly from the socio-economic characteristics of our country is one of the important questions of the Iranian labor market. In this study, we seek to answer the question of whether the economic participation rate of married women will increase if the gender gaps in wages, job findings and job losses among women and men are eliminated in the Iranian labor market. To answer this question using household expenditure and income data and labor force data, we show that between the two categories of occupations, in terms of the share of women's... 

Shot peening is a cold-working process commonly used in industry to improve the fatigue performance, stress corrosion resistance and surface nano-crystallization of metallic parts. This process extends fatigue life via two mechanisms: Preventing the crack growth due to compressive residual stresses and, preventing the crack initiation because of increased material hardness. These mechanisms are the results of the bombardment of the component's surface with small spherical particles. In this research, an analytical model is developed for estimating the residual stress distribution induced by shot peening process. The modifications of the developed analytical model are related to... 

Solid-State Drives (SSDs) provide high performance, low power consumption, and hence are widely used in the I/O cache of enterprise storage systems and high performance servers. Although employing high performance SSDs in the I/O cache of storage systems significantly improves system performance, it comes with significant reliability threats for write operations upon power failures. In order to provide high level of reliability, storage architectures employ SSDs in I/O cache with RAID-1 configuration, however, such configuration only partially mitigates the reliability issues of the SSDs. In this thesis, we analyze the reliability of SSD-based I/O caches against power outage and high...