Analysis of Firm-level Factors Fffects in Success of Financing with Credit Guarantee-Case Study of Iranian Technology Fund

, M.Sc. Thesis Sharif University of Technology Fatemi Khorasgani, Ali (Author) ; Souzanchi Kashani, Ebrahim (Supervisor)

Abstract

Financing is an important barrier in growth path of small and medium-sized technology-based firms. Using guarantee letters to ease access of such firms to credit, is one way to encounter this barrier. In this study, the pioneer research and technology fund in offering this service to technology-based firms in Iran have been considered. Credit guarantee issuance records of this fund illustrates that none of credit guarantee letters certified by this fund has been defaulted yet. Comparison of fund’s credit scoring model with Chandler’s framework for organizational capabilities reveals that the fund does not investigate marketing and managerial capabilities in its credit scoring model. So, the...

, M.Sc. Thesis Sharif University of Technology Fatemi, Reza (Author) ; Abedian, Ali (Supervisor)

Abstract

Retrofitting of old mechanical structures by composite materials is one of the most important issues of the world.High reproducing and replacement cost of structures leads to, researchers try to retrofitting old structures and increase their capabilities and so increase their service age. Their research results leads to decreasing cost in one hand and introduce new application of composites in aviation industry in the other hand.Retrofitting mechanical structures show us the important of elements with more stress than the others. The probability of failure is more in these element than the other that we call critical element.These elements in fact are critical parts of an aerial structures...

On-Line Energy Management for Fault-Tolerant Real-Time Embedded Systems

, M.Sc. Thesis Sharif University of Technology Aflaki Khorasgani, Mehdi (Author) ; Ejlali, Alireza (Supervisor)

Abstract

Providing low-power fault tolerance is usually an important requirement in real-time embedded systems. A faulty result in safety-critical systems and a failure to meet a deadline in hard real-time systems can cause catastrophic consequences for the system or environment. Therefore, these systems must be highly reliable and meet real-time constraints. Slack time in time redundancy techniques (e.g. roll-back recovery) can be used to increase system reliability and to save energy. Time redundancy techniques are suitable from an energy consumption point of view but may not be sufficiently reliable for tight real-time constraints. In the condition of tight timing constraints, the hardware...

Parametric Study and Numerical Simulation of Spiral Wound Heat Exchanger Performance at Cryogenic Temperatures

, M.Sc. Thesis Sharif University of Technology Hosseinian Khorasgani, Mohsen (Author) ; Afshin, Hossein (Supervisor)

Abstract

Cryogenic is the study of physical phenomena at temperatures below 123 Kelvin. One of the applications of cryogenic science is the liquefaction of gases. In the liquefaction cycles of gases, such as helium liquefaction, fluidization occurs in the pressure reducing valve but temperature of the gas should be greatly reduced before it enters the pressure reducing valve. For this purpose, high-performance heat exchangers should be used. Spiral Wound is one of the heat exchangers that has ability to achieve over 90% efficiency due to its structure. Researchs in the field of design and simulation of spiral heat exchangers are limited and are done with a lot of simple assumptions such as constant...

A lattice-based threshold secret sharing scheme

, Article 2014 11th International ISC Conference on Information Security and Cryptology, ISCISC 2014 ; Sept , 2014 , pp. 173-179 ; ISBN: 9781479953837 Khorasgani, H. A ; Asaad, S ; Eghlidos, T ; Aref, M ; Sharif University of Technology

2014

Abstract

In this paper, we introduce a method of threshold secret sharing scheme in which secret reconstruction is based on celebrated Babai lattice algorithm. In order to supply secure public channels for transmitting shares to parties, we need to ensure that there is no quantum threats to these channels. One solution for this problem can be utilization of lattice cryptosystems for these channels which requires designing lattice based secret sharing schemes. We indicate that our scheme is asymptotically correct. Moreover, we analyze the security of our scheme by giving a quantitative proof of security from the view point of information theory

Estimating Air Travel Demand in Iran’s Domestic Routes

, M.Sc. Thesis Sharif University of Technology Movaffagh Yami, Mostafa (Author) ; Fatemi Ardestati, Farshad (Supervisor) ; DadPay, Ali (Co-Advisor)

Synchronicity and Firm’s Network Structure

, M.Sc. Thesis Sharif University of Technology Farajpour Bibalan, Mohammad Reza (Author) ; Fatemi, Farshad (Supervisor) ; Ebrahimnejad, Ali (Supervisor)

Abstract

There are two viewpoints about pyramid shareholding and cross ownership; first, shareholders want to increase their control over firms. Second, by pyramidal structure and cross ownership, firms internalize weakness of financial market and lack of some financial institutions. In order to identify reason(s) of this issue, we must first recognize affiliated firms and their networks. In this study, we identify firms’ networks in Iran by three definitions: shareholder network, owner network and director network. Then we estimate any correlation between returns synchronicity and being in a same network. Our results show that more than 40% of studied firms are affiliated. Also there is positive...

Clock and Data Recovery based on Phase Shifting and Accordion Oscillator

, M.Sc. Thesis Sharif University of Technology Fatemi Mofrad, Ali (Author) ; Fotowat Ahmady, Ali (Supervisor) ; Akbar, Fatemeh (Supervisor)

Abstract

The continuous growth of network traffic and people's demand for higher data rates, have driven wireline communication systems towards higher data rates. In these systems, the power consumption of these transmitters and receivers is a crucial and influential factor. This paper presents two different solutions to reduce the power consumption and area of these systems. In the first solution, a low-power phase shifter with variable phase and amplitude control is introduced. The changes in these parameters are mutually orthogonal, ensuring that a change in one characteristic does not affect the others. This phase shifter can be used to generate clock pulses with different phases in wireline...

Design of an UWB Analogue Detector Receiver for Biomedical Applications

, M.Sc. Thesis Sharif University of Technology Fatemi, Mohammad Reza (Author) ; Sharifkhani, Mohammad (Supervisor) ; Fotowat-Ahmady, Ali (Co-Advisor)

Abstract

Emergence of the implantable biomedical microsystems and personal area networks in recent years result in a new class of biomedical systems that requires data transmition in short range at various data rates. Performing with ultra low power consumption and long battery life are crucial in these systems. Therefore, designing low power radios for these systems is still an active research area. Ultera wideband systems are specially considered for implementations because of their potential characteristics.
In this dissertation, different biomedical applications and data communication approaches are surveyed. Then, Different architectures of UWB receivers are reviewed. To implement a low...

The Impact of Financial Constraints on Firm Exports: A Case Study of Manufacturing Firms in Iran

, M.Sc. Thesis Sharif University of Technology Fakhr Fatemi, Mahdi (Author) ; Madani Zadeh, Ali (Supervisor) ; Mahmoud Zadeh, Amineh (Supervisor)

Abstract

Exporting firms face a range of challenges when entering international markets, among which financial constraints are particularly significant. Financial constraints can impair a firm’s cash flow, making it difficult to finance the fixed costs associated with export market entry. This study constructs a firm-level index to measure the degree of financial constraint and examines its impact first on the probability of export participation, and then on the volume of exports. The analysis is based on data from Iran’s industrial firms between 2008 and 2019 (1387–1398 in the Iranian calendar). The effect of financial constraints on the probability of exporting is estimated using logit and linear...

A Lattice based Secret Sharing Scheme with Changeable Threshold

, M.Sc. Thesis Sharif University of Technology Amini Khorasgani, Hamidreza (Author) ; Aref, Mohammad Reza (Supervisor) ; Eghlidos, Taraneh (Co-Advisor)

Abstract

The need to protect the key in cryptosystems has been a motivation of studying secret sharing schemes. A secret sharing scheme is a method for sharing a secret data (key) by distributing some values, called shares, to a number of participants in such a way that only some authorized subset of them can recover the secret. In a threshold secret sharing scheme, authorized subsets are those whose size are at least a given value called threshold of the scheme. Increasing the attacker capabilities in achieving the participants’ shares, requires an increase in the threshold parameter. In a changeable threshold secret sharing scheme, participants ate able to compute new shares from their old shares...

The regulated market for kidneys in Iran

, Article Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering, 22 August 2011 through 23 August 2011 ; Volume 80 LNICST , August , 2012 , Pages 62-75 ; 18678211 (ISSN) ; 9783642309120 (ISBN) Fatemi, F ; Sharif University of Technology

2012

Abstract

We study the kidney market in Iran. The most effective treatment for end-stage renal disease is a kidney transplant. While the supply of cadaveric kidneys is limited, the debate has been focused on the effects of the existence of a free market for human organs. Economists as well as medical and legal researchers are divided over the issue. Iran has a unique kidney market which has been in place for over 20 years, frequently reporting surprising success in reducing the waiting list for kidneys. This paper demonstrates how the Iranian system works

The effect of geometrical properties of reservoir shale barriers on the performance of Steam-assisted Gravity Drainage (SAGD)

, Article Energy Sources, Part A: Recovery, Utilization and Environmental Effects ; Volume 34, Issue 23 , 2012 , Pages 2178-2191 ; 15567036 (ISSN) Fatemi, S. M ; Sharif University of Technology

2012

Abstract

Many bitumen reservoirs contain shale layers of varying thickness, lateral extent, and frequency. These shale layers, depending on their size, vertical and horizontal locations, and continuity throughout the reservoir, may act as a flow barrier and severely reduce vertical permeability of the pay zone and slow down the steam-assisted gravity drainage steam chamber development. Therefore, to improve productivity in these reservoirs, understanding of the effects of reservoir heterogeneities has become necessary. This work presents numerical investigation of the effects of shale barriers on steam-assisted gravity drainage performance when applied to produce mobile heavy oil. The most concern of...

The applicability of expanding solvent steam-assisted gravity drainage (ES-SAGD) in fractured systems

, Article Petroleum Science and Technology ; Volume 28, Issue 18 , Oct , 2010 , Pages 1906-1918 ; 10916466 (ISSN) Fatemi, S. M ; Sharif University of Technology

2010

Abstract

The aim of this contribution is to evaluate the performance of an expanding solvent steam assisted gravity drainage (ES-SAGD) process in naturally fractured systems. Steam-assisted gravity drainage (SAGD) and ES-SAGD processes have been investigated in both conventional and fractured reservoir models and the effect of networked fractures on the recovery mechanism and performance of ES-SAGD has been investigated. Operational parameters such as steam quality, vertical distances between wells, and steam injection temperature have been also evaluated. Finally, to study the effect of a well's horizontal offset, a staggered ES-SAGD well configuration has been compared to a stacked ES-SAGD

Simulation study of Steam Assisted Gravity Drainage (SAGD) in fractured systems

, Article Oil and Gas Science and Technology ; Volume 64, Issue 4 , 2009 , Pages 477-487 ; 12944475 (ISSN) Fatemi, S. M ; Sharif University of Technology

2009

Abstract

The Steam Assisted Gravity Drainage (SAGD) process, a developed Enhanced Oil Recovery (EOR) process to recover oil and bitumen, has been studied theoretically and experimentally in conventional reservoirs and models and is found a promising EOR method for certain heavy oil reservoirs. In this work simulation studies of the SAGD process were made on different fractured models consisting of fractures in both Near Well Region (NWR) and Above Well Region (AWR) and even in the presence of networked fractures. At early stage of the SAGD process in fractured system, steam moves through the fractures first and then the matrix blocks are heated primarily by conduction and possibly some steam...

Effective Permeability of Isotropic Overlapping Sandbodies in 2D Using Percolation Theory

, M.Sc. Thesis Sharif University of Technology Fatemi, Amin (Author) ; Masihi, Mohsen (Supervisor)

Abstract

Permeability is an essential parameter used for reservoir evaluation, simulation and management to optimize oil recovery. The conventional approach to estimate reservoir connectivity, conductivity, sweep efficiency and other critical information for decision-making is to build detailed geological models, which are then upscaled to a coarser grid where flow simulations are run. However, this takes many hours to be carried out even for a single realization practically. In practice, a very small number of realizations are considered and consequently the true uncertainty in the results is very poorly estimated. In this study, a statistical model of isotropic overlying sandbodies is used to...

Analysing the Effects of Monetizing Energy Carriers Subsidy on Expenditures and Welfare Criteria of Iranian Households

, M.Sc. Thesis Sharif University of Technology Einian, Majid (Author) ; Fatemi, Farshad (Supervisor)

Abstract

In this thesis, with a review on policy simulation and economic reform analysis literature, we design a suitable method to analyze the effects of monetizing energy carriers subsidy on welfare criteria of Iranian households. The selected method is limited general equilibrium that needs demand estimates of goods, services and energy. In firs step,based on 13 years of data on “Iranian Households’ Expenditures and Income” surveys, data are provided as a pseudo-panel. Demand equations are estimated using “Seemingly Unrelated Regressions” for panel data, and elasticities are calculated. In the next step, we evaluated the equivalent variation and equivalent gain measures in each price scenarios....

Adverse Selection in Iranian Life Insurance Market

, M.Sc. Thesis Sharif University of Technology Mirtaher, Abdolkarim (Author) ; Fatemi, Farshad (Supervisor)

Abstract

This thesis finds evidence for the presence of adverse selection in the Iranian life insurance market. We use a unique dataset including more than one million policyholders’ profile information alongside their chosen life insurance coverage from the largest Iranian insurance company. Our results not only find evidence in support of adverse selection in this market, but also consider the magnitude of adverse selection relatively notable. Moreover, we found that in addition to the coverage, the other dimensions of contract could be the potential source of adverse selection. Particularly, we focused on the insurance duration and the payment method (monthly, annually, all-in-advance)....

Examining Evolution of Technology Performance in the Global Smartphone Industry

, M.Sc. Thesis Sharif University of Technology Fatemi, Arman (Author) ; Kiamehr, Mehdi (Supervisor)

Abstract

In this research we have studied the changes in the technology performance in the smartphone industry, and by using theoretical models in technology management literature, we have compared this performance with coustomer’s required level of performance. The study shows that after 2011, the level of customer satisfactions depends less on the technology performance and more on the price. This observation is consistent with Christiensen’s suggested model for technology performance, in which after a certain point technology’s performance surpasses the customer’s need. In addition, we have studied the effect of modular design for smartphones on the customer’s satisfaction. We found that...

Living with Uncertainty

, M.Sc. Thesis Sharif University of Technology Fatemi, Arvin (Author) ; Azadegan, Ebrahim (Supervisor)

Abstract

Michael Zimmerman in his book Living with Uncertainty has objected to two views of moral obligation, namely objective and subjective view. Two overcome these problems he suggests a third view which he calls prospective view and tells us that our moral obligation is determined by the prospection that each of our choices give us. In this thesis first I review Zimmerman’s objections to objective and subjective view. Then I try to suggest a solution for the objective view