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    A Critical Review of the Social Construction of Technology Thesis: Do Society Constructs Technology?

    , M.Sc. Thesis Sharif University of Technology Shafi Khani, Mohamad Amin (Author) ; Taqavi, Mostafa (Supervisor)
    Abstract
    However “The Social Construction of Technology (SCOT)” is the title of a thesis in the domain of Science and Technology Studies (STS), it has an important effect on the philosophy of technology. In this paper I try to elaborate and criticize SCOT’s approach. For this purpose we need to answer the question “what is Technology exactly?”. So in the first chapter, I defined Technology. After reviewing some of it’s famous definitions, I defined the joint of technologies based on the “Dual nature of technical artefacts” thesis. Because of the wide range of technologies, I have concentrated on “Technical Artefacts”, although I was not inattentive to other meanings of technology, especially... 

    Developing a Simulator for Concurrent Execution of Multiple Workflows in Fog Computing Environment

    , M.Sc. Thesis Sharif University of Technology Rayej, Mohamad Amin (Author) ; Izadi, Mohamad (Supervisor)
    Abstract
    Fog computing environment consists of several devices which distribute across an arbitrary topology. Each of these devices is capable of carrying out a designated computation simultaneously with other devices. One of the common ways of describing a computation is through the usage of workflows. Workflow is a flexible and formal way of modeling tasks and their requirements for execution. A workflow is essentially a DAG. Therefore, it can model the data dependency between tasks quite accurately. The complex structure of a workflow in conjunction with the homogenous nature of devices in a fog environment makes it difficult to find a resource management algorithm to minimize execution time, used... 

    Investigation of the Drop Tank Influence on Range and Optimization of Its Geometry

    , M.Sc. Thesis Sharif University of Technology Nasiri Khansari, Mohamad Tagi (Author) ; Durali, Mohamad (Supervisor)
    Abstract
    This project focuses on the design of fuel drop tanks for airplanes that add minimal drag and positive lift to the flying object. This will obviously effect the stability and dynamic performance of the airplane. To reduce adverse dynamic effects the tank was divided to several segment with a special emptying sequence. The add-on tank has to have no interference with the object existing systems and require minimum structural changes in the object. Several designs were proposed and the one gaining highest marks was selected. The flow field and the dynamic behavior of combined vehicle and drop tanks were studied using FE simulations. The result shows that adding a drop tank with optimized... 

    Transfer optimization in transit networks: Headway and departure time coordination

    , Article IEEE Conference on Intelligent Transportation Systems, Proceedings, ITSC ; 2011 , Pages 1531-1536 ; 9781457721984 (ISBN) Khani, A ; Shafahi, Y ; Sharif University of Technology
    2011
    Abstract
    This paper studies the scheduling problem in transit networks in order to decrease transfer waiting time. Transfer waiting time is calculated based on headway and departure time of intersecting routes and is divided into two parts. The first part can be reduced by changing departure times and was studied by the authors previously. The focus of the present research, however, is to minimize the second part of the transfer waiting time, dependent on the headways. The proposed optimization model in this paper includes both parts and is a nonlinear mathematical programming model. The model is decomposed to the departure time setting model (DSM) and the headway setting model (HSM). A solution... 

    Robust model predictive control of nonlinear processes represented by Wiener or Hammerstein models

    , Article Chemical Engineering Science ; Volume 129 , 2015 , Pages 223-231 ; 00092509 (ISSN) Khani, F ; Haeri, M ; Sharif University of Technology
    Elsevier Ltd  2015
    Abstract
    Representing nonlinear systems by linear models along with structured or unstructured uncertainties and applying robust control strategies could reduce the computational complexity in comparison with implementing the nonlinear model predictive controllers. In this paper design of robust model predictive controllers which are based on special classes of nonlinear systems representations called Wiener and Hammerstein are presented. The proposed algorithms approximate the nonlinear systems by uncertain linear models and reduce online the computational demands in the control implementation. The advantages of the proposed approaches are illustrated by two examples  

    Smooth switching in a scheduled robust model predictive controller

    , Article Journal of Process Control ; Volume 31 , 2015 , Pages 55-63 ; 09591524 (ISSN) Khani, F ; Haeri, M ; Sharif University of Technology
    Elsevier Ltd  2015
    Abstract
    Abstract This paper proposes a bumpless transfer method to overcome the problem of switching jumps in a scheduled robust model predictive control approach. A scheduled robust model predictive controller implements a set of local robust model predictive controllers based on an on-line switching strategy. This method could enlarge the domain of attraction efficiently but the transient response might be hampered by spikes appearing at the moment of switching between adjacent local controllers. The proposed algorithm could enhance the transient response by implementing some intermediate controllers augmented to the main control scheme to solve the problem without needing more computation. The... 

    Constrained tracking control for nonlinear systems

    , Article ISA Transactions ; Volume 70 , 2017 , Pages 64-72 ; 00190578 (ISSN) Khani, F ; Haeri, M ; Sharif University of Technology
    2017
    Abstract
    This paper proposes a tracking control strategy for nonlinear systems without needing a prior knowledge of the reference trajectory. The proposed method consists of a set of local controllers with appropriate overlaps in their stability regions and an on-line switching strategy which implements these controllers and uses some augmented intermediate controllers to ensure steering the system states to the desired set points without needing to redesign the controller for each value of set point changes. The proposed approach provides smooth transient responses despite switching among the local controllers. It should be mentioned that the stability regions of the proposed controllers could be... 

    Effect of sectionalizing switches malfunction probability on optimal switches placement in distribution networks

    , Article International Journal of Electrical Power and Energy Systems ; Volume 119 , July , 2020 Khani, M ; Safdarian, A ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    Sectionalizing switches (SSs) are installed in distribution networks to provide ring and maneuver points, thereby increasing service reliability. These switches are either manual switches (MSs) or remote controlled switches (RCSs). The switches are usually assumed to be fully reliable. However, in practice, their performance is not always ideal. Actually, the switches may sometimes experience malfunction, which reduces their ability to enhance system reliability. The present study proposes a model to consider the malfunction possibility of the switches in their optimal placement problem. The model helps to minimize the total costs of SSs as well as the interruption costs incurred by... 

    A novel multi-access scheme for UWB-PPM communication systems

    , Article European Transactions on Telecommunications ; Volume 18, Issue 4 , 2007 , Pages 389-401 ; 1124318X (ISSN) Khani, H ; Azmi, P ; Sharif University of Technology
    2007
    Abstract
    In this paper, it is shown that some spikes exist in power spectral density (PSD) of ultra-wideband-time-hopping-pulse-position-modulation (UWB-TH-PPM) transmitted signal. Analytical and numerical simulation results show that these spikes severely degrade UWB-TH-PPM system bit-error-rate performance and must be properly removed. This paper proposes a novel multi-access scheme that uses both direct-sequence (DS) and time-hopping (TH) multi-access schemes to remove these harmful spikes. Analytical and numerical simulation results show that the proposed scheme removes the spikes from the PSD of the UWB-TH-PPM transmitted signal and yields better performance. In this paper, the performance of... 

    Enlarging the region of stability in robust model predictive controller based on dual-mode control

    , Article Transactions of the Institute of Measurement and Control ; Volume 43, Issue 14 , 2021 , Pages 3085-3092 ; 01423312 (ISSN) Khani, F ; Haeri, M ; Sharif University of Technology
    SAGE Publications Ltd  2021
    Abstract
    Industrial processes are inherently nonlinear with input, state, and output constraints. A proper control system should handle these challenging control problems over a large operating region. The robust model predictive controller (RMPC) could be an linear matrix inequality (LMI)-based method that estimates stability region of the closed-loop system as an ellipsoid. This presentation, however, restricts confident application of the controller on systems with large operating regions. In this paper, a dual-mode control strategy is employed to enlarge the stability region in first place and then, trajectory reversing method (TRM) is employed to approximate the stability region more accurately.... 

    Distributed Cardiovascular System Modeling

    , M.Sc. Thesis Sharif University of Technology Khani, Mehrdad (Author) ; Jahed, Mehran (Supervisor)
    Abstract
    Simulation of cardiovascular system functionality during various physiological conditions is essential at different diagnostic and clinical levels. A first step in studying the roots of cardiovascular diseases and abnormal activity is to study a practical yet complete model of the cardiovascular system. In this thesis we introduced a new approach for defining the distributed model of the cardiovascular system. Initially, we chose an appropriate subsystem, namely Arch of Aorta, and proposed a distributed model for it. The elements of the proposed model were nonlinear RLC elements that simulate resistance, blood viscosity and vessel elasticity respectively. To minimize the system complexity,... 

    Coordinated Scheduling in Public Transportation by Aim of Transfer Time Reduce

    , M.Sc. Thesis Sharif University of Technology Khani, Alireza (Author) ; Shafahi, Yusof (Supervisor)
    Abstract
    The thesis is about transit network scheduling problem and aims to minimize waiting time at transfer stations. The problem is formulated as a mixed integer programing model that gives departure times of vehicles in lines so that passengers can transfer between lines at transfer stations with minimum waiting time. The model is expanded to another model by considering an extra stoping time of vehicles at transfer stations as a new variable set. By calculationg the optimal value for these variables, transfers could be done in a better condition. The sizes of the models are small enough that the models can be solved for small and medium size networks using regular MIP solvers. Moreover, a... 

    Analysis and Enhancement of Distributed Timely Computations Regarding Age of Information

    , M.Sc. Thesis Sharif University of Technology Khani, Zeynab (Author) ; Ashtiani, Farid (Supervisor)
    Abstract
    Edge computing networks are ideal for emerging applications that require computation-intensive and timely processing, as they enable complex computation tasks to be offloaded and computed in parallel and distributed manner. However, for many applications that the calculations are of one type, such as determining the location of an object, it is crucial to insure the freshness of the information. Age of Information (AoI) metric is employed to measure freshness. This research focuses on identifying an appropriate model for calculating the average AoI in distributed computing systems and determining the optimal decision-making policy to enhance it. In essence, the primary objective is to... 

    A Stochastic Model for Cancer Tumor Growth

    , M.Sc. Thesis Sharif University of Technology Miraboutalebi, Mohamad Hosein (Author) ; Foroughmand Arabi, Mohamad Hadi (Supervisor) ; Alishahi, Kasra (Co-Supervisor)
    Abstract
    Cancer can be defined as a stochastic phenomenon. Thus, the tumor growth can be defined as a stochastic process. A Cancer tumor can be analyzed by its geometric shape. Furthermore, computing fractal dimension of shapes is a useful technique to analyze chaosity and complexity of shapes. This approach can be used to compare results from laboratory with simulated results of a mathematical model. A stochastic model of tumor growth will be presented. And some geometrical properties will be analyzed through computer simulation of the model  

    Modeling of the mutual effect of dynamic precipitation and dislocation density in age hardenable aluminum alloys

    , Article Journal of Alloys and Compounds ; Volume 683 , 2016 , Pages 527-532 ; 09258388 (ISSN) Khani Moghanaki, S ; Kazeminezhad, M ; Sharif University of Technology
    Elsevier Ltd  2016
    Abstract
    A model has been proposed to capture the complex strain rate effect on dynamic precipitation of GP zones in an age-hardenable aluminum alloy. The contributions of vacancies and dislocations to dynamically formed GP zones have been specified in the model. It has been demonstrated that the proposed model is capable for predicting the contribution of each dynamic precipitation mechanisms, accurately, which are acting during deformation. Furthermore, the vacancy and dislocation evolutions during deformation have been considered in this modeling. The effect of strain rate by considering different mechanisms of dynamic precipitation of GP zones has been studied and confirmed by experimental data... 

    Effects of non-isothermal annealing on microstructure and mechanical properties of severely deformed 2024 aluminum alloy

    , Article Transactions of Nonferrous Metals Society of China (English Edition) ; Volume 27, Issue 1 , 2017 , Pages 1-9 ; 10036326 (ISSN) Khani Moghanaki, S ; Kazeminezhad, M ; Sharif University of Technology
    Nonferrous Metals Society of China  2017
    Abstract
    Microstructure and mechanical properties of AA2024 after severe plastic deformation (SPD) and non-isothermal annealing were investigated. The non-isothermal treatment was carried out on the severely deformed AA2024, and the interaction between restoration and precipitation phenomena was investigated. Differential scanning calorimetry, hardness and shear punch tests illustrate that static recovery and dissolution of GPB zones/Cu–Mg co-clusters occur concurrently through non-isothermal annealing. Scanning electron microscope and electron backscatter diffraction illustrate that non-isothermal annealing of deformed AA2024 up to 250 °C promotes the particle-free regions and also particle... 

    A Biomechanical Model for Evaluation of Shoulder Function: Detecting the
    Relationship Between Muscles Activation Patterns and Shoulder Joint Torques Using Synergy Concept

    , M.Sc. Thesis Sharif University of Technology Nassajian Moghadam, Mohamad Reza (Author) ; Parnianpour, Mohamad (Supervisor) ; Asghari, Mohsen (Supervisor)
    Abstract
    The effects of combined task demands on the way muscles are recruited to balance external loads during posture and movement is of great importance in quantitative analysis of upper arm function. Pain and disability of shoulder joint is becoming more important as population spends more often interacting with computers in seated position and carrying repetitive tasks using upper extremities. Shoulder joint that is more dependent on the muscles for its normal function than other joints such as hip due to its small articular surface and large range motion has been used here to study its coordination during isometric exertions. Since, the numbers of tasks that could be performed are enormous. In... 

    Introducing a Simulation-Based Model to Improve the Design and Layout of Workstations Inside Airport Terminals in Iran

    , M.Sc. Thesis Sharif University of Technology Amini Esfidvajani, Amin Mohammad (Author) ; Alvanchi, Amin (Supervisor)
    Abstract
    The airport terminal is difficult to plan and design due to the different components and the intricate complexity of its parts. At the airport terminal, we face a queue system which simulation is always a good way to analyze. In addition, computer simulation using modern softwares with the capability to model different types of systems, including the airport terminal, while being less realistic than analytical models, is less costly than operational Exercise.In this study, a supportive approach for better and specific management of Iranian airport terminal buildings with discrete-event simulation is proposed, considering the need for managing the airport terminals building in the country and... 

    Design and Implementation of a Multi-Standard Crypto-Processor

    , M.Sc. Thesis Sharif University of Technology Bahadori, Milad (Author) ; Sharif Khani, Mohammad (Supervisor)
    Abstract
    The crypto-processors are used for encryption and decryption of the sensitive and important information. A crypto-processor converts input plaintext to ciphertext by an input key using a particular cryptographic algorithm. It also converts ciphertext to plaintext by the same or another key. Cryptographic standards are divided in two types: symmetric key algorithms (private key) and asymmetric key algorithms (public key). Current processors generally support only one or a few number of cryptographic algorithms. The motivation of this project is design and implementation of a multi-standard crypto-processor which supports the most of symmetric and asymmetric cryptographic algorithms, such as... 

    Physician Induced Demand Case Study of Caesarean Section in Iran

    , M.Sc. Thesis Sharif University of Technology Khani, Mohammad (Author) ; Fatemi Ardestani, Farshad (Supervisor)
    Abstract
    In standard models, the demand function is considered to be independent from the supply function and the intersection of these curves is considered to determine the price and quantity in the market. The alternative model, called “inducement hypothesis”, describes how the supply side can persuade consumers through particular advices, induce demand for the provided services and though shift the demand curve; i.e. demand is not independent from supply. For the case of physicians, this hypothesis is known as “physician induced demand”. In fact, this theory describes the supply-side moral hazard in the production market. This hypothesis may have vast applications which are different from...