Combination Services in A Cloud Manufacturing System With Regard to Quality as A Fuzzy Criteria

, M.Sc. Thesis Sharif University of Technology Nateghi, Mohammad (Author) ; Hooshmand, Mahmoud (Supervisor)

Abstract

Today, due to the development of information technology and fierce competition among manufacturers, the need to reduce the production costs and increase the variety are strongly felt. Each process in the cloud manufacturing is first considered as a service product development, and then, specializing each of these services, provides us a lower cost, along with a higher accuracy, and quality.The modern world is the world full of uncertainty. The uncertainty, which causes the manufacturers to develop products that consume a large quantity of, fixed costs. That is why utilizing such a perspective can reduce investment risk in a new product development. Combining the production services by...

UWB Channel Modeling Using Time-Domain Ray Tracing

, M.Sc. Thesis Sharif University of Technology Nateghi, Amirhossein (Author) ; Shishegar, Amir Ahmad (Supervisor)

Abstract

Nowadays, wireless communication plays a key role in everyday lives and has many different applications. Today’s communication systems require high bandwidths in order to transfer data with higher bitrates. Among these, modeling a wireless channel is one of the most important challenges in wireless communications. Modeling an indoor Ultra-Wide-Band (UWB) wireless channel has been involved in a great number of researches. In order to model a UWB channel, we need to correctly investigate electromagnetic waves inside the buildings. Amongst different methods that are used for this aim, ray tracing method is one of the most accurate and fast ones. In this thesis, time-domain reflection and...

Response-only modal identification of structures using limited sensors

, Article Structural Control and Health Monitoring ; Volume 20, Issue 6 , 2013 , Pages 987-1006 ; 15452255 (ISSN) Abazarsa, F ; Ghahari, S. F ; Nateghi, F ; Taciroglu, E ; Sharif University of Technology

2013

Abstract

Herein, we propose a method based on the existing second-order blind identification of underdetermined mixtures technique for identifying the modal characteristics - namely, natural frequencies, damping ratio, and real-valued partial mode shapes of all contributing modes - of structures with a limited number of sensors from recorded free/ambient vibration data. In the second-order blind identification approach, second-order statistics of recorded signals are used to recover modal coordinates and mode shapes. Conventional versions of this approach require the number of sensors to be equal to or greater than the number of active modes. In the present study, we first employ a parallel factor...

Estimation of Bank Loan Interest Rate and Determining its Correlated Factors: A Case Study of Listed Companies in Iran

, M.Sc. Thesis Sharif University of Technology Nateghi, Morteza (Author) ; Madanizadeh, Ali (Supervisor) ; Mahmoodzadeh, Amineh (Supervisor)

Abstract

Bank loans are one of the main sources of financing for enterprises and the most important source of financing for large enterprises in Iran. Uncertainty about future conditions and asymmetric information between the bank and the firm puts the provision of loans at risk. According to the principle of proportionality of risk and return, the interest rate of bank facilities should be proportional to the risk that the bank incurs in return for granting the loan. In general, the interest rate of bank loans can be affected by three types of risks: the credit risk of the applicant firm, the risk of the lender bank and the macroeconomic environment risk. In this study, we try to estimate the...

Radiation and convection heat transfer optimization with MHD analysis of a hybrid nanofluid within a wavy porous enclosure

, Article Journal of Magnetism and Magnetic Materials ; Volume 566 , 2023 ; 03048853 (ISSN) Hosseinzadeh, K ; Erfani Moghaddam, M. A ; Nateghi, S ; Behshad Shafii, M ; Ganji, D. D ; Sharif University of Technology

Elsevier B.V 2023

Abstract

Thermal performance maximization is a necessity in various systems that are dealing with any scale of heat flux. This requirement has been intensified due to introduction of more complex and highly crammed products, making heat dissipation a daunting task. Addressing this challenge, a curved porous star-shaped enclosure with a rounded cavity and occupied by hybrid nanoparticles of Fe3O4-Al2O3 scattered uniformly in 1-Hexanol has been simulated by Galerkin finite element method. The temperature difference between inner cavity and outer wavy surface stirred the heat flux within the bounded domain. The determinants of thermal evolution are classified by porosity alteration, radiation intensity,...

Bacterial biopolymers in tissue engineering and regenerative medicine; current applications and future perspective

, Article Biocatalysis and Agricultural Biotechnology ; Volume 54 , 2023 ; 18788181 (ISSN) Bakhshandeh, B ; Mohammadipanah, F ; Sadat Mirtaleb, M ; Maddah Gazani, M ; Nateghi, S ; Abbasi, P ; Sharif University of Technology

Elsevier Ltd 2023

Abstract

Tissue engineering (TE), a fast-growing field of regenerative medicine, has been designed to replace diseased or damaged tissues. As cellular factories, microbes produce a wide range of intracellular and extracellular biopolymers using energy resources. Bacterial biopolymers play an essential role in the competition of microorganisms with competitors. With the detailed knowledge of these bacterial metabolites, extensive applications have been provided in the medicine, food, and drug industry. Bacterial biopolymers, including polysaccharides, polyamides, polyphosphates, polyesters, and enzymes, with vast diversity and desirable properties, are the most frequently used products in TE. Herein...

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)

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...

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

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

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...

Non-Scratch, Antibacterial And Self-cleaning SiO2/TiO2 Nano Composite Coating on Surgical Tools By Sol-Gel

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

Abstract

In this study TiO2/SiO2 thin films were prepared by sol-gel method from Tetra isopropylortho Titanate(TIPT) as the principle of TiO2 material with Tera ethoxysilane(TEOS) as the principle of SiO2 material to achieve high scratch-resistant , antibacterial and self-cleaning surface area under the effect of various percentage of SiO2 . Film deposition was carried out using a dip-coating technique and heat-treatment was used at 700ºC to achieve crystalline of films with excellent adherence the of substrate.
The surface morphology of the films has been observed by Scanning Electron Microscope (SEM) and the tribological properties of the surface were investigated by Atomic Force Microscope...

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 the Effects of Parking Pricing and Improving Public Transportation Policies on Private Car Use Reduction in Central Business District

, M.Sc. Thesis Sharif University of Technology Salavati, Mohammad Ali (Author) ; Kermanshah, Mohammad (Supervisor)

Abstract

Nowadays, with population growth and vehicle traffic increase, only providing transportation supply couldn’t answer the transportation demand. One of the most important solutions to reduce traffic is transportation demand management (TDM). In this research, the effects of parking pricing and improving public transportation services on private car demand reduction in city center are examined. The data are collected from private cars users in the city center of Isfahan through interviews. By stated preference method, the impacts of parking price and public transit travel time and other related factors were investigated. For this purpose, binary logit, multinomial logit and nested logit models...

Iran’s Air Quality Modeling Using CMAQ-WRF Coupled Model

, M.Sc. Thesis Sharif University of Technology Mohegh, Mohammad Hassan (Author) ; Arhami, Mohammad (Supervisor)

Abstract

Industrialization has brought about air pollution which is one of the most important factors threatening human health. The most efficient method to improve air quality include preventing the emission of pollutants by making laws and regulations. In order to set appropriate regulations, there needs to be a correct understanding of the problem. The purpose of this research is to identify such factors and create a correct understnding of the problem in Iran by constructing a Model of Iranian air qulity. The model used in this research, CMAQ is one of the most comprehensive and state of the art models in transport of pollutnts and chemical reactions in the atmosphere. The inputs into CMAQ...

H.264 Decoder for Portable Application

, M.Sc. Thesis Sharif University of Technology Alizadeh, Mohammad Sadegh (Author) ; Sharifkhani, Mohammad (Supervisor)

Abstract

As mobile multimedia services become popular, it is expected that mobile devices provide more multimedia functions such as real-time video playback, TV watching, and video games. However, real-time video applications running on mobile devices are heavily constrained by their limited computing power, compared to high-end consumer devices. In order to playback a high resolution video on mobile devices, a typical approach would be to fully decode video bitstream into the pixel-domain, and then spatially downscale the decoded frames at a desired resolution. However, due to large computation and memory required for decoding followed by downscaling, this approach is unsuitable for real-time video...