Sustainable-Resilient Supplier Selection Through Fuzzy Multi-Criteria Decision Making Approaches

, M.Sc. Thesis Sharif University of Technology Varchandi, Sahar (Author) ; Akbari Jokar, Mohammad Resa (Supervisor) ; Memari, Ashkan (Co-Supervisor)

Abstract

Today, with the expansion of business relations at international levels, there are many organizations that operate in global supply chains. Activities at such levels face new types of challenges in various fields of "supply chain management" pillars, of which "supplier selection" is one of them. The possibility of unexpected events, the need to comply with environmental protection laws, as well as the need to take into account social considerations, are among the things that have increased by being in larger supply chains, making it challenging to provide the basic resources needed in such chains and forcing their managers to considering considerations other than what they have always...

Adaptive Teaching of the Iranian Sign Language Based on Continual Learning Algorithms

, M.Sc. Thesis Sharif University of Technology Memari, Morteza (Author) ; Taheri, Alireza (Supervisor)

Abstract

In addition to being their primary means of communication with the people around them, sign language for deaf children plays a significant role in shaping their intellectual and cognitive development. Research has shown that the use of robots in education has a substantial impact on the learning process of the learner. As the teaching process requires long-term interaction with different users, the use of adaptable techniques enables the creation of a social robot capable of productive interaction with users of varying performance levels. One of the objectives of this research is to use continual learning algorithms to enhance adaptability in the teaching process. Another goal is to design...

Mixed-convection flow of nanofluids and regular fluids in vertical porous media with viscous heating

, Article Industrial and Engineering Chemistry Research ; Volume 50, Issue 15 , 2011 , Pages 9403-9414 ; 08885885 (ISSN) Memari, M ; Golmakani, A ; Dehkordi, A. M ; Sharif University of Technology

2011

Abstract

In this article, the problem of combined forced and natural convection in a vertical porous channel for both regular fluids and nanofluids has been solved by perturbation and numerical methods, taking into account the influences of viscous heating and inertial force. In this regard, various types of viscous dissipation models, including the Darcy model, the power of drag force model, and the clear fluid compatible model, were considered to account for viscous heating. In addition, the mass flux of nanoparticles was also considered in terms of Brownian and thermophoresis mechanisms. The velocity and temperature distributions of both the regular fluid and nanofluid and the Nusselt number...

Liquid-Liquid equilibrium data, density, viscosity, and interfacial tension of ternary system (Toluene-Acetic Acid-Water) at 298.15 K: Experiment and correlation

, Article Journal of Chemical and Engineering Data ; Volume 62, Issue 12 , 2017 , Pages 4133-4143 ; 00219568 (ISSN) Memari, M ; Molaei Dehkordi, A ; Seifkordi, A. A ; Sharif University of Technology

2017

Abstract

Liquid-liquid equilibrium (LLE) data, density, viscosity, and interfacial tension for the ternary system of toluene-acetic acid-water were measured at 298.15 K and 101.7 kPa. The Othmer-Tobias and the Hand correlations were used to check the reliability of the experimental tie-lines. Moreover, the distribution coefficient and the separation factor were explored. It was found from the experimental results that a maximum separation factor value happens at an acetic acid mass fraction of 0.02 in the organic phase. Density, viscosity, and interfacial tension were correlated using the appropriate correlations such that the predicted results have excellent agreement with the experimental data. The...

An optimization study of a palm oil-based regional bio-energy supply chain under carbon pricing and trading policies

, Article Clean Technologies and Environmental Policy ; Volume 20, Issue 1 , 2018 , Pages 113-125 ; 1618954X (ISSN) Memari, A ; Ahmad, R ; Abdul Rahim, A. R ; Akbari Jokar, M. R ; Sharif University of Technology

Springer Verlag 2018

Abstract

Biomass residues due to their low bulk density typically require frequent transportation from biomass plantations in rural areas to conversion bio-energy power plants. This issue contrasts with environmental protection strategies, especially when power plants are facing different carbon reduction policies that enforce them to emit less than a given specific carbon amount. Although several researchers have investigated bio-energy supply chains concerning environmental policies, the majority of studies have been devoted to strategic decisions over a single planning period. This paper presents a multi-period bio-energy supply chain under carbon pricing (carbon tax) and carbon trading...

Studying Instances of Conflict of Interest in Some Job Positions in Iran’s Ministry of Health, Treatment and Medical Education

, M.Sc. Thesis Sharif University of Technology Memari Beyraq, Behzad (Author) ; Talebian, Masoud (Supervisor) ; Fatemi Ardestani, Farshad (Co-Supervisor)

Abstract

This study investigates and enumerates instances of conflict of interests in some job positions in Iran’s Ministry of Health, Treatment and Medical Education. To achieve this goal, we interviewed people involved in the health field and reviewed job descriptions as well. By adopting the prevalent definition of conflict of interests regarding the duties, authorities, and responsibilities, instances of conflict of interests has been relatively identified in each position. The results show that the main reasons (determinants) for cases of conflict of interests can fall into three categories. First, duties of positions are in such a way that being a shareholder, CEO, and member of the board of...

Empathizing and systemizing skills influence risky decision making in children

, Article Learning and Individual Differences ; Volume 40 , 2015 , Pages 22-26 ; 10416080 (ISSN) Memari, A. H ; Shayestehfar, M ; Gharibzadeh, S ; Barzegary Banadkooki, E ; Hafizi, S ; Moshayedi, P ; Sharif University of Technology

Elsevier Ltd 2015

Abstract

Tow-mode theories explain that risky behaviors in young individuals may be the result of competition between an affective system (e.g., Empathizing system) and a deliberative system (e.g., Systemizing system). We aimed to investigate a total of 134 children aged 7-12. years old on scores of risky decision making and empathizing and systemizing measures. The primary analysis indicated that systemizers showed higher sensitivity to punishment than those in balanced or empathizer classes (F (2,130) = 14.8, p < 0.001). Furthermore empathizers indicated higher level of risk taking than balanced and empathizer children (F (2,130) = 5.027, p = 0.005). Providing further support for two-mode theories...

Experimental and Numerical Investigation on the Single Drop Liquid-liquid Mass Transfer in the Presence of Magnetic Nano-particles (Ferrofluids) and Magnetic Field

, Ph.D. Dissertation Sharif University of Technology Memari, Mohammad (Author) ; Molaie Dehkordi, Asghar (Supervisor) ; Seif Kordi, Ali Akbar (Co-Supervisor)

Abstract

The main objective of the present work was to improve the turbulence in single drops using ferrofluids (magnetic nanoparticles) in the presence of uniform and oscillating magnetic fields. In this regard, magnetite nanoparticles ($\mathrm{Fe_3O_4}$) were synthesized by co-precipitation method, characterized using DLS, FT-IR, XRD, VSM, and TEM, and their stability was checked by UV-Vis. The obtained results indicate the proper synthesis of nanoparticles with a mean diameter of about 20 nm and by coating their surfaces by silane that were well stabilized in the base fluid. In the numerical section, the governing equations of transport phenomena for a single drop containing magnetic fluids were...

Construction of an Experimental Device for Foaming Agent and an Experimental Study of the Properties of Foaming Agent

, M.Sc. Thesis Sharif University of Technology Mohammad Karami (Author) ; Bazargan, Mohammad (Supervisor)

Abstract

The primary purpose of acidizing operations in the oil and gas industry is to enhance hydrocarbon production. Acidizing has been a common and conventional method for years, especially when production engineers face issues like declining reservoir pressure leading to reduced production rates. Initially, the treatment solution is referred to as matrix acidizing. In acidizing operations, different additives are combined with the acid to control its behavior in the reservoir. These additives may include iron control agents, corrosion inhibitors, friction reducers, and more. Incompatibility among these additives, the acid, and reservoir fluids can lead to severe damage to the reservoir....

Numerical Analysis of An Annular Gas Turbine Combustor

, M.Sc. Thesis Sharif University of Technology Gandomi, Mohammad Hossein (Author) ; Farshchi, Mohammad (Supervisor)

Abstract

The goal of this research is the simulation of the annular combustion chamber of the turbine engine utilized by liquid fuel. The achievement to this goal will lead to create numerical tools for parametric study, analysis and combustion chamber designing.For this reason simple geometry has been considered. This simplicity of geometry causes to facilitate in parametric study and decrease in saving time for modeling and meshing. This combustion chamber is a simplified model of engine CF6. In recent study, the k – ε realizable model has been used for turbulence modeling. For non-adiabatic condition, chemical reaction is dissolved by utilizing probability density function along with laminar...

A misbehavior‐tolerant multipath routing protocol for wireless Ad hoc networks [electronic resource]

, Article International Journal of Research in Wireless Systems (IJRWS) ; Vol. 2, Issue 9, pp. , Sep. 2013 Sedghi, H. (Haniyeh) ; Pakravan, Mohammad Reza ; Aref, Mohammad Reza ; Sharif University of Technology

Abstract

Secure routing is a major key to service maintenance in ad hoc networks. Ad hoc nature exposes the network to several types of node misbehavior or attacks. As a result of the resource limitations in such networks nodes may have a tendency to behave selfishly. Selfish behavior can have drastic impacts on network performance. We have proposed a Misbehavior-Tolerant Multipath Routing protocol (MTMR) which detects and punishes all types of misbehavior such as selfish behavior, wormhole, sinkhole and grey-hole attacks. The protocol utilizes a proactive approach to enforce cooperation. In addition, it uses a novel data redirection method to mitigate the impact of node misbehavior on network...

Theoretical and Experimental Study to Conversion of AUC to UO2 by Microwave Heating

, Ph.D. Dissertation Sharif University of Technology Labbaf, Mohammad Hossein (Author) ; Otukesh, Mohammad (Supervisor) ; Ghannadi Maragheh, Mohammad (Co-Advisor) ; Ghasemi, Mohammad Reza (Co-Advisor)

Estimating Possible Effects of Subsidies in Competition and Development of Fixed Broadband Internet

, M.Sc. Thesis Sharif University of Technology Mohammadi, Mohammad Ali (Author) ; Vesal, Mohammad (Supervisor) ; Rahmati, Mohammad Hossein (Supervisor)

Abstract

In this work, the dynamic competition between firms providing internet services is studied. The framework is Markov equilibrium whereby structural parameters are obtained using two-step estimations, allowing for analyzing the situation in case of subsidies for service upgrade. The results show that such subsidy has little effect on the number of firms while increasing the number of fast firms

SAR Imaging Using the TomoSAR Technique to Resolve Multiple Scatterers

, M.Sc. Thesis Sharif University of Technology Omati, Mohammad Mahdi (Author) ; Bastani, Mohammad Hassan (Supervisor) ; Karbasi, Mohammad (Co-Supervisor)

Abstract

During the last few years, the study of urban environment structures is considered as a research field of interest in remote sensing. In satellite observations of the earth's surface, continuous imaging in terms of time and space has caused the remote sensing technique to be proposed as a useful and efficient tool for the analysis of urban areas. Obtaining quantitative spatial information from the urban environment in fields such as determining the height of buildings plays an essential role in urban planning, monitoring damage to buildings, establishing communication bases and digital cities. During the last two decades, the use of Tomosar approach in order to reconstruct the structures of...

Joint Optimization of Computation Offloading and Resource Allocation in Mobile Edge Computing Networks

, M.Sc. Thesis Sharif University of Technology Shokouhi, Mohammad Hossein (Author) ; Pakravan, Mohammad Reza (Supervisor) ; Hadi, Mohammad (Co-Supervisor)

Abstract

Mobile edge computing (MEC) is a promising technology that aims to resolve cloud computing’s issues by deploying computation resources at the edge of mobile network and in the proximity of users. The advantages of MEC include reduced latency, energy consumption, and load on access and mobile core networks, to name but a few. Despite all the aforementioned advantages, the mobility of mobile network users causes the traditional MEC architecture to suffer from several issues, such as decreased efficiency and frequent service interruption. One of the methods to manage users’ mobility is virtual machine (VM) migration, where the VM containing the user’s task is migrated to somewhere closer to...

Estimating Price Elasticity of Natural Gas Demand in Iran's Residential Sector: A Regression Discontinuity Approach

, M.Sc. Thesis Sharif University of Technology Makhsousi, Mohammad Hossein (Author) ; Rahmati, Mohammad Hossein (Supervisor) ; Vesal, Mohammad (Supervisor)

Abstract

Estimating the price elasticity of gas demand involves complexities depending on the gas market structure and pricing mechanisms in different countries. Distinguishing between supply and demand shocks and block pricing are among the main challenges that can cause endogeneity in elasticity estimates. Iran's domestic gas network, one of the largest and most extensive household gas markets, is divided into five climatic zones based on weather conditions. The pricing steps for these five climates during the five cold months are such that a customer in a warmer climate pays higher prices. Conversely, the pricing steps for the seven warm months are the same for all climates. This policy creates a...

Estimate the Effect of Religiosity on Voter Turnout

, M.Sc. Thesis Sharif University of Technology Jarrahi, Mohammad Mahdi (Author) ; Rahmati, Mohammad Hossein (Supervisor) ; Vesal, Mohammad (Supervisor)

Abstract

The correlation between religious adherence and voter turnout is widely studied. However, whether the relation is causal is an open question. We use Household Expenditures and Income Survey (HEIS) data in Iran, which encompasses nine distinct religious expenditures. These expenditures have low correlation with each other and represent different aspects of religious adherence. We use Imamzadeh (some historical holy shrines) as Instruments to estimate the causal effect of religious expenditures on voter turnout. The results reveal that religious expenditures influence both presidential and parliamentary voter turnout, with a notably stronger impact on presidential elections

Simulation and Control of an Aromatic Extractive Distillation Column

, M.Sc. Thesis Sharif University of Technology Karima, Mohammad Mahdi (Author) ; Shahrokhi, Mohammad (Supervisor)

Abstract

In this study steady state and dynamic simulation of an NFM extractive distillation unit for seperation of aromatics and non-aromatic components has been carried out. Column output composition obtained with experimental binary coefficients is compared with those obtainded by UNIFAC equation. The results indicate that using UNIFAC for all binrary coefficients results in an unacceptable error in concentration of benzene. If the experimental binary coefficents of benzene with NFM are used and the rest are calculated by UNIFAC equation, the simulation results will be very close to those obtained via experimental binary coefficients. Also it is shown that considering a constant efficiency for all...

Investigation of Transport Phenomena in Clarification of Beer by Membrane Using CFD Method

, M.Sc. Thesis Sharif University of Technology Kazemi, Mohammad Amin (Author) ; Soltanieh, Mohammad (Supervisor)

Abstract

During the brewing process, beer alternately goes through different chemical and biochemical reactions and solid–liquid separation stages. The clarification at the final step of brewing is a highly critical stage when it comes to producing a clear and bright beer. Recently, membrane technology has been successfully used in beer clarification, wherein Kieselguhr (diatomaceous earth) filtration is replaced by cross-flow microfiltration. The most important disadvantages of using microfiltration in clarification of beer is the fouling and flux decline during the process. The phenomenology of fouling mechanisms is still undefined and selection of an appropriate technique for flux enhancement in...

Design and Manufacture of a Burner for Transforming Natural Gas to Reduction Gas

, M.Sc. Thesis Sharif University of Technology Ershad, Mohammad Saleh (Author) ; Halali, Mohammad (Supervisor)

Abstract

Different methods can be used to produce reduction gas. One example is using coal. But today there’s a tendency to use natural gas. One way of transforming natural gas to reduction gas is to burn it with gases produced by combustion, such as or vapor; usually a catalyst is used in this method. Another method is burning natural gas directly with oxygen or air. The recent method is of benefit especially in Iran, because of available natural gas resources and avoiding catalyst problems. Designing a burner for this purpose is an important step in reaching this goal. In this project such a burner is designed and manufactured. The burner manufactured in this project burns natural gas with...