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...

, 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...

Delay Analysis and Improving in Distributed Computing

, M.Sc. Thesis Sharif University of Technology Doudi, Fatemeh (Author) ; Ashtiani Mofrad Tehrani, Farid (Supervisor) ; Maddah Ali, Mohammad Ali (Supervisor)

Abstract

In this contemporary era, distributed computing is a vital solution for many applications. The traditional computing scheme based on allocating one complete computation to only one server is not efficient anymore. Delay has a very important role in computation’s performance especially for the computation at the edge of the network. To alleviate the effect of big data and complex algorithms, distributed computing is a very promising solution. In this structure, all computations are divided into some small tasks or coded, based on the system's status and will be executed in parallel. In fully parallelized distributed computing, a task is broken into N smaller tasks and whenever all N subtasks...

Aerodynamic Design Methodology for Changing Axial Compressor Capacity

, M.Sc. Thesis Sharif University of Technology Mofrad, Ehsan (Author) ; Ghorbanian, Kaveh (Supervisor)

Abstract

Axial compressor design is a very complex and expensive process. In general, for design and development of a new axial compressor, manufacturing companies usually intend to employ an existing and successful axial compressor as an starting point and modify and upgrade it. In this regard, dimensional scaling is a common method for derivative axial compressors. The goal of dimensional scaling is to get a different capacitywhile minimizing the development time and cost. In this thesis, theNASA eight stage transonic axial flow compressor is chosen as the base model for dimensional scaling to lower and upper size of its original dimension. The scaled compressor is analyzed with a quasi 2-D code....

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...

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 effect of conductive aligned fibers in an injectable hydrogel on nerve tissue regeneration

, Article International Journal of Pharmaceutics ; Volume 645 , 2023 ; 03785173 (ISSN) Mozhdehbakhsh Mofrad, Y ; Shamloo, A ; Sharif University of Technology

Elsevier B.V 2023

Abstract

Injectable hydrogels are a promising treatment option for nervous system injuries due to the difficulty to replace lost cells and nervous factors but research on injectable conductive hydrogels is limited and these scaffolds have poor electromechanical properties. This study developed a chitosan/beta-glycerophosphate/salt hydrogel and added conductive aligned nanofibers (polycaprolactone/gelatin/single-wall carbon nanotube (SWCNT)) for the first time and inspired by natural nerve tissue to improve their biochemical and biophysical properties. The results showed that the degradation rate of hydrogels is proportional to the regrowth of axons and these hydrogels’ mechanical (hydrogels without...

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

Simulation of the effects of oxygen carriers and scaffold geometry on oxygen distribution and cell growth in a channeled scaffold for engineering myocardium

, Article Mathematical Biosciences ; Volume 294 , 2017 , Pages 160-171 ; 00255564 (ISSN) Zehi Mofrad, A ; Mashayekhan, S ; Bastani, D ; Sharif University of Technology

2017

Abstract

This study proposes a mathematical model to evaluate the impact of oxygen carriers and scaffold geometry on oxygen distribution and cell growth in a 3D cardiac construct using computational fluid dynamics (CFD). Flow equations, oxygen balance equation and cell balance equation were solved using special initial and boundary conditions. The modeling results revealed that 55% increase in cardiac cell density occurred by using 6.4% perfluorocarbon oxygen carrier (PFC) compared to pure culture medium without PFC supplementation. Moreover, the effects of the scaffold geometry on cell density were examined by changing the channel numbers and the construct length. A 30% increase in the average cells...

Design of Injectable Hydrogel Scaffold based on Smart Polymer in Tissue Engineering

, M.Sc. Thesis Sharif University of Technology Mozhdehbakhsh Mofrad, Yasaman (Author) ; Shamloo, Amir (Supervisor)

Abstract

Nerve damage is one of the factors affecting the quality of life of patients. The nervous system does not have the ability to repair large injuries, and autologous transplantation, which is the standard treatment method for nerve injuries, is faced with a shortage of donors and a decrease in the function of the donor site. Tissue engineering hydrogels, due to their similarity to the natural tissue of the stomatal body, are a hope for the repair of nerve tissue. In this research, an injectable, minimally invasive and temperature-sensitive hydrogel based on chitosan-etaglycerophosphate-sodium hydrogen carbonate salt or trisodium phosphate salt containing aligned nanofibers made of gelatin and...

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...

Directional migration and differentiation of neural stem cells within three-dimensional microenvironments

, Article Integrative Biology (United Kingdom) ; Volume 7, Issue 3 , Jan , 2015 , Pages 335-344 ; 17579694 (ISSN) Shamloo, A ; Heibatollahi, M ; Mofrad, M. R. K ; Sharif University of Technology

Royal Society of Chemistry 2015

Abstract

Harnessing neural stem cells to repair neuronal damage is a promising potential treatment for neuronal diseases. To enable future therapeutic efficacy, the survival, proliferation, migration and differentiation of neural stem/progenitor cells (NPCs) should be accurately studied and optimized in in vitro platforms before transplanting these cells into the body for treatment purposes. Such studies can determine the appropriate quantities of the biochemical and biomechanical factors needed to control and optimize NPC behavior in vivo. In this study, NPCs were cultured within a microfluidic device while being encapsulated within the collagen matrix. The migration and differentiation of NPCs were...

A Ring Selection Platform for Treatment of Keratoconus

, M.Sc. Thesis Sharif University of Technology Khademi Mofrad, Amir Hossein (Author) ; Asghari, Mohsen (Supervisor)

Abstract

Corneal keratoconus is one of the common eye diseases that usually occurs in the teenage years or the beginning of the third decade of life. In this disease, the cornea thins and loses its original shape and becomes conical. To treat this disease, ophthalmologists use different methods such as using glasses, contact lenses (hard and soft), corneal transplantation, and also corneal cross-linking, each of these methods has limitations, on the other hand, considering that The disease progresses and its severity increases, Ophthalmologists use corneal rings to treat this disease in more advanced stages, implanting a suitable ring in the patient's cornea both increases the strength of the...

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...