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zamani--atefeh
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Dynamics of Protein-Embedded Vesicles in Simple Shear Flow
, M.Sc. Thesis Sharif University of Technology ; Jalali, Mir Abbas (Supervisor) ; Khoshnood, Atefeh (Co-Advisor)
Abstract
Studying the dynamics of vesicles in simple shear flow is the first step to decipher the dynamics of cells in flows or the motion of vesicle-based nanoparticles in vessels for drug delivery. The deformation of vesicle in shear flow changes the permeability of its membrane and may lead to its rupture, both of which correlate with the transportation of vesicle cargos to their environment, especially important in drug delivery. The deformation of vesicles in shear flow not only depends on the physical properties of the whole system, such as temperature, but also on the mechanical properties of three media: vesicle membrane plus vesicle’s inner and outer fluid. The effect of the mechanical...
Effects of Graphene Nanopores and Temperature on DNA Sequencing Using Molecular Dynamics
, M.Sc. Thesis Sharif University of Technology ; Meghdari, Ali (Supervisor) ; Khoshnood, Atefeh (Co-Advisor)
Abstract
Distinguishing the structure of DNA is of outmost importance in the medicine and agriculture industry nowadays. Various methods have been suggested so far; however, high costs, incorrect results, and time-taking process are among main defects of them. Scientists try to find new ways for recognizing DNA structure and system in order to overcome such problems. One of these new methods is absorbing and passing DNA through Nano-pores in an electrolyte solution under the influence of an electrical field. The basis of this method is the ionized currents which occur due to the passing of DNA through Nano-pores. Because each DNA base pairs can form a barrier corresponding to a unique measured value,...
Oxidation of Sulfides and Olefins in the Presence of Nanocluster Polyoxotungstate–intercalated Layered Double Hydroxide Nanoparticles as a Catalyst
, M.Sc. Thesis Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor)
Abstract
In this study, polyoxometalate (POM) intercalated in the layered double hydroxide (LDH) was synthesized by a selective ion-exchange method. For this purpose, the nanocluster [VW12O40]3- was immobilized on the Mg2+/A13+/Cl–LDH support. The heterogeneous catalyst was characterized by FT-IR, XRD, SEM and analysis of ICP. The LDH-POM was applied as a catalyst in efficient oxidation of sulfides to sulfoxides using UHP as oxidant and CH3OH/ CH¬2¬Cl¬2 ¬as a solvent at room temperature, as well as epoxidation of olefins using TBHP as an oxidants and C¬2H4Cl2 as a solvent in 84°C. This catalyst showed excellent catalytic activities for a substrate/catalyst ratio (200:1). For example, this catalytic...
Long Period Variable Stars in the Local Group Galaxies
, M.Sc. Thesis Sharif University of Technology ; Rahvar, Sohrab (Supervisor) ; Javadi, Atefeh (Co-Supervisor)
Abstract
In this thesis, the star formation history and evolution of IC 1613 dwarf galaxy and NGC 5128 giant elliptical galaxy has been studied. About IC 1613, our result shows that the star formation history of the galaxy is roughly constant in 5 Gyr ago and this support that the galaxy had been isolated at least in 5 Gyr ago. About NGC 5128, we can see that the star formation rate has suddenly increased in 700 Myr and 3.5 Gyr ago. This results in very good agreement with literature support that the galaxy has experienced some mergers with smaller gas rich galaxies
Study and Comparison the Incidence of Dutch Disease in Iranian Economy in Two Periods of Oil Shock
, M.Sc. Thesis Sharif University of Technology ; nili, Masoud (Supervisor) ; Madanizadeh, Ali (Supervisor)
Abstract
This paper studies and compares the effect of "Dutch disease" in Iranian economy in two periods of rising oil price (1973-1978) and (2004-2010). The study presents a DSGE model to analysis the behavior of economic variable in both periods and to address this question that whether or not policy maker has learning behavior. The model consists of households, final goods producers who divided in tradable goods and non-tradable goods sector and the government. I use calibration methods to estimate models parameters.Comparison of simulated results and the actual macroeconomic variables in Iran during 1338-1390 indicates that, first of all Dutch disease effect occur in both periods of oil shock so...
Reaction-diffusion equations with polynomial drifts driven by fractional brownian motions
, Article Stochastic Analysis and Applications ; Volume 28, Issue 6 , Oct , 2010 , Pages 1020-1039 ; 07362994 (ISSN) ; Sharif University of Technology
2010
Abstract
A reaction-diffusion equation on [0, 1]d with the heat conductivity k > 0, a polynomial drift term and an additive noise, fractional in time with H > 1/2, and colored in space, is considered. We have shown the existence, uniqueness and uniform boundedness of solution with respect to k Also we show that if k tends to infinity, then the corresponding solutions of the equation converge to a process satisfying a stochastic ordinary differential equation
New method of determination for pressure and shear frictions in the ring rolling process as analytical function
, Article Journal of Solid Mechanics ; Vol. 6, issue. 3 , 2014 , pp. 322-333 ; ISSN: 20083505 ; Sharif University of Technology
2014
Abstract
Ring rolling is one of the most significant methods for producing rings with highly precise dimensions and superior qualities such as high strength uniformity, all accomplished without wasting any materials. In this article, we have achieved analytical formulas for calculating the pressure and shear friction over the contact arcs between the rollers and ring in the ring rolling process for the material in general nonlinear hardening property. We have also asserted the best mathematical model to predict friction for rolling processes. The method we use is based on calculating the analytical stress distribution. In other words, by using of Saint-Venan principal the stress components are...
Sparse array design for millimeter-wave imaging
, Article 2016 IEEE Antennas and Propagation Society International Symposium, APSURSI 2016 - Proceedings, 26 June 2016 through 1 July 2016 ; 2016 , Pages 1039-1040 ; 9781509028863 (ISBN) ; Fakharzadeh, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
In this paper, the design of an efficient sparse array, used to reconstruct the image from millimeter-wave signals, is presented. The proposed array takes advantage of the sparsity concept of the image in the spatial Fourier domain to reduce the number of array elements such that the beam pattern of the designed array meets the desired beamwidth and sidelobe level. Simulation and measured results confirm the effectiveness of the proposed design on high-quality reconstruction of the image, while 85% reduction in the number of elements is achieved as well as the reduction in scan time and system complexity
A feature fusion based localized multiple kernel learning system for real world image classification
, Article Eurasip Journal on Image and Video Processing ; Volume 2017, Issue 1 , 2017 ; 16875176 (ISSN) ; Jamzad, M ; Sharif University of Technology
2017
Abstract
Real-world image classification, which aims to determine the semantic class of un-labeled images, is a challenging task. In this paper, we focus on two challenges of image classification and propose a method to address both of them simultaneously. The first challenge is that representing images by heterogeneous features, such as color, shape and texture, helps to provide better classification accuracy. The second challenge comes from dissimilarities in the visual appearance of images from the same class (intra class variance) and similarities between images from different classes (inter class relationship). In addition to these two challenges, we should note that the feature space of...
1.5-D sparse array for millimeter-wave imaging based on compressive sensing techniques
, Article IEEE Transactions on Antennas and Propagation ; Volume 66, Issue 4 , April , 2018 , Pages 2008-2015 ; 0018926X (ISSN) ; Fakharzadeh, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
The goal of this paper is to reduce the antenna count in a millimeter (mm)-wave imaging system by proposing both hardware and software solutions. The concept of image sparsity in the transform domain is utilized to present the compressive sensing (CS) formulation for both mono-static and multistatic imaging at mm-wave frequencies. To reduce the complexity of the imaging system and reconstruction process, we introduce 1.5-D array structure, which is a random sparse array with orthogonal element locations. It is shown that the peak signal-to-noise ratio (PSNR) of the reconstructed image obtained by a 1.5-D array with 65% sparsity is very close to the PSNR of a uniform 2-D array for mono-static...
An efficient strategy to overproduce glutamic acid in Corynebacterium glutamicum fermentation
, Article Scientia Iranica ; Volume 8, Issue 3 , 2001 , Pages 203-206 ; 10263098 (ISSN) ; Roostaazad, R ; Sharif University of Technology
Sharif University of Technology
2001
Abstract
In this paper, effect of penicillin addition in enhancing the secretion of glutamic acid by Corynebacterium glutamicum was studied. The proper time of adding penicillin to maximize glutamic acid production was found to drift at repeated trials. In contrast, maximum acid productivity was obtained when penicillin was injected at a proper biomass concentration of about 7.7 gram dry weight per lit (gdw/l). Moreover, rate of consumption of sugar and ammonia through the course of glutamic acid fermentation was monitored. In production phase, these two rates were correlated properly with a ratio of 3.2:1 which is comparable to the theoretical stoichiometric value of 5:1. Therefore, through feeding...
Credit Risk Analysis of a Bank's Loan Portfolio
, M.Sc. Thesis Sharif University of Technology ; Zamani, Shiva (Supervisor)
Abstract
Risk management is one of the most important topics in banking. Risk management in banking is divided to several categories including credit risk. Credit risk is also divided to individual credit risk and portfolio credit risk. In Iran many of banks have worked on individual credit risk models, but few of them have worked on portfolio models because these models have developed only in recent years. In our project we present three categories of credit risk models and then analyze the data of a private bank in Iran with CreditPortfolioView model. In CreditPortfolioView model, macroeconomic parameters are used to analyze the correlated behavior of individuals as a benchmark in different...
Project Finance and Motivations and Optimum Approach of Using it in LNG Industry of Iran
, M.Sc. Thesis Sharif University of Technology ; Zamani, Shiva (Supervisor)
Abstract
Project Finance is a novel approach in financing big projects. High debt ratio, independency to promoter credit and establishing a special purpose company, are some of project finance characteristics that could be very beneficial in some projects. Liquid Natural Gas (LNG) is a solution for exporting natural gas to far destination. As economical and environmental benefits of using natural gas have been increased in recent years, LNG industry has been experienced rapid growth. In this project we analyze project finance and then describe economical motivation of using this method in LNG industry of Iran.
Collapsible Behavior of Gorgan Loess Using Odeometer
, M.Sc. Thesis Sharif University of Technology ; Haeri, Mohsen (Supervisor)
Abstract
In nature, there are types of soils that when goinging under stress at constant moisture, or increase of moisture at constant stress, or change of both characters, they show a sudden and high level decrease in their volume. These type of soils are named as Collapsible soils. Iran is one of the countries that at some parts of its land collapsible soils are found. In this research by using of laboratory equipments, the volume change behavior of collapsible loess soils of Gorgan plain (North of Iran) is evaluated under increase of water content and inundation stress. In these experiments, the usual odeometer cell has been used for exploring the behaviour of collapsibility and volume change of...
Modeling of Corporate Default Risk with Considering Latent Factors
, M.Sc. Thesis Sharif University of Technology ; Zamani, Shiva (Supervisor)
Abstract
Credit risk is one important type of various types of financial risks that banks and financial institutions are exposed to it. Therefore credit risk management for banks and other financial institutions that finance corporations and individuals, has special importance. To make decision about financing clients of the bank and managing credit risk, it is essential to measure credit risk of these clients. In recent decades there are many efforts to measure credit risk and therefore various models have been created for assessing it. In this research, we study the effects of Macroeconomic, firm specific and latent variables on clients default risk, in the context of reduced-form models. The...
Evaluation of GARCH Forecasting Performance Under Different Error Term Distributions
, M.Sc. Thesis Sharif University of Technology ; Zamani, Shiva (Supervisor)
Abstract
Volatility is the most important components in numerous finance applications. So, the methods of volatility forecast with reasonable accuracy require a deep attention.In this thesis with considering several distributions for error term, GARCH forecasting performance is evaluated on the intra- day data of "Foolad" stock returns by two loss functions of "MAE" and "HMAE". This evaluation is done in three forecast horizons, 1 day, 5 days and 20 days. Finally, the result of this study is as follows. GARCH (1, 1) forecast model with skewed t- student error distribution has the minimum value in the both loss functions for 1 day and 5 day forecast horizons. Also GARCH (1, 1) forecast model with t-...
Credit Scoring for Maskan Bank Customers
, M.Sc. Thesis Sharif University of Technology ; Zamani, Shiva (Supervisor)
Abstract
Credit scoring is a mechanism used to quantify the risk factors relevant for an obligor’s ability and willingness to pay. Credit scoring has become the norm in modern banking, due to the large number of applications received on a daily basis and the increased regulatory requirements for banks. The meaning of credit scoring is to assign scores to the characteristics of debt and borrowers, historical default, and other loss experienced as an indication of the risk level of the borrower. The aim of the credit score model is to build a single aggregate risk indicator for a set of risk factors.
In this study, current method in which Maskan bank will give a loan is explained. We developed a...
In this study, current method in which Maskan bank will give a loan is explained. We developed a...
Evaluation of The Informational Efficiency of Tehran Securities Market
, M.Sc. Thesis Sharif University of Technology ; Zamani, Shiva (Supervisor)
Abstract
In the present research, the weak level efficiency of securitise market is reviewed and examined .Therefore the “Random Walk Hypothesis” has been examined on the time series of daily efficiency index of TEHRAN SECURITISE MARKET. The main difference between this research and the previous researches which have been performed previously in Iran, is the method of Hypothesis Test. The” Variance Ratio Test” has been used as a method of Hypothesis’ Test. In the second chapter, the theoretical and experimental literatures of this research has been described in detail. In parallel with the ” Variance Ratio Test”, the impact of the Day of week and the “HETROSCEDASITY TEST” also has been...
Evaluating Overconfidence in Tehran Trade Market
, M.Sc. Thesis Sharif University of Technology ; Zamani, Shiva (Supervisor)
Abstract
Behavioral finance researchers have introduced behavioral biases, derived from psychology, to financial models in order to make them more realistic and to increase their explanatory power.One of the best known of these biases, considered in behavioral finance literature, is overconfidence, which means investors overestimate their own knowledge and ability to evaluate securities. Several theoretical models have studied the effects of this bias on financial markets and many empirical models have examined their assumptions, looking for whether investors are overconfident or not. Explained by these models, price overreaction to private information arrival and underreaction to public signal, is...
Day of The Week Effect on Tehran Stock Exchange
, M.Sc. Thesis Sharif University of Technology ; Zamani, Shiva (Supervisor)
Abstract
The present study investigated day of the week effect on stock market returns and the stock market returns and volatility relationship in Tehran Stock Exchange. In this part two regression models is been used and theory that effect of days are meaningful on return and also the theory of meaningfulness and being equal of relation between return and volatility in different days of the week has been examined on index return of all market and on industry indexes in separately. Therefore we have utilized information from time series of total index week days categorized into 8 industries during 2008-2013. The results obtained on weekdays effect on the index of the first model and second model...