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    Modeling the Brain’s Probabilistic Prediction of Oddball Paradigm

    , Ph.D. Dissertation Sharif University of Technology Mousavi, Zahra (Author) ; Karbalai Aghajan, Hamid (Supervisor)
    Abstract
    The brain is constantly anticipating the future of sensory inputs based on past experiences. When new sensory data is different from predictions shaped by recent trends, neural signals are generated to report this surprise. Surprise leads to garnering attention, causes arousal, and motivates engagement. It motivates the formation of an explanation or updating of current models. Three models have been proposed for quantifying surprise as the Shannon, Bayesian, and confidence-corrected surprises. In this thesis, we analyze EEG and MEG signals recorded during oddball tasks to examine and statistically compare the value of temporal/ spatial components in decoding the brain’s surprise. We... 

    Surface Modification of UF Membrane by Cationic Polymers

    , M.Sc. Thesis Sharif University of Technology Abdolmaleki, Hamid Reza (Author) ; Mousavi, Abbas (Supervisor)
    Abstract
    One of the most efficient and effective methods of water and wastewater treatment is the use of membranes and can be a good alternative to traditional methods such as adsorption, chemical coagulation and .... One of the limitations of this method is membrane fouling, which limits its use in industry.In this study, ultrafiltration membrane made by phase inversion method from a combination of PVDF and SPES polymers and surface modified with hyperbranched polyethylene imine and its performance in cationic coating paint purification was investigated. Also, the performance of this membrane has been investigated by calculating the separation rate, pure water flux, contact angle and specifications... 

    Design of Local Rule for Cellular Automata Using Evolutionary Algorithms

    , M.Sc. Thesis Sharif University of Technology Mousavi, Samane Sadat (Author) ; Beigy, Hamid (Supervisor)
    Abstract
    Cellular automata is a model for physical systems that has homogenous and simple components. Simple components, which are called cells, have local interactions creating complicated global emergent of behaviour. In the field of cellular automata, there are two basic problems: forward and inverse problems. Characterizations of cellular automata rule are studied in forward problem, but in inverse problem, there exists a description of cellular automata and we should find a rule or a set of rules that satisfy the given description. This problem belongs to the class of NP problems and hence heuristic algorithms such as evolutionary algorithms have been used for solving it. Since rules space and... 

    Simulation of Droplet Sorting in Microfluidic Systems

    , M.Sc. Thesis Sharif University of Technology Fattahi, Hamid Reza (Author) ; Mousavi, Ali (Supervisor) ; Asghari, Mohsen (Supervisor)
    Abstract
    A new microfluidic device is introduced for sorting the particles based on the hydrodynamic resistance induced in a microchannel which is not needed for additional detection or sorting modules. Hydrodynamic resistance affects physical properties, such as size and deformability of the particle. This device could apply application in cell sorting for remedies, diagnostics, and industrial applications. The device design is performed using an equivalent resistance model, and also numerical simulations are performed. For validation of the results, they are compared with experimental results. Moreover, we will discuss threshold particle size and will introduce a way to approximate it to ... 

    Effect of Electromagnetic Field on Membrane Fouling in Filtration Process

    , M.Sc. Thesis Sharif University of Technology Rouina, Mohammad (Author) ; Kariminia, Hamid Reza (Supervisor) ; Mousavi, Abbas (Supervisor)
    Abstract
    Current research studies the effect of electromagnetic field on reducing precipitation on membrane surface in reverse osmosis. Reverse osmosis is one of the most widely applied methods for water desalinization. Despite its advantages over other desalinization techniques, suffers from shortcomings such as blockage of membrane surface. Use of magnetic fields for reducing precipitation in process equipment, the so-called magnetic treatment, has been studied and practiced for decades. This research intends to study the effect of electromagnetic field on water and its mineral content, and the possibility of its application as a method for reducing precipitation and blockage in reverse osmosis... 

    Facilitation of Transscleral Drug Delivery

    , M.Sc. Thesis Sharif University of Technology Mousavi Khamene, Zeynab (Author) ; Abdekhodaie, Mohammad Jafar (Supervisor) ; Seifkordi, Aliakbar (Supervisor) ; Ahmadieh, Hamid (Co-Supervisor)
    Abstract
    In the present research the methods and challenges to ocular drug delivery have been investigated with more emphasis on ocular diseases that do not have any approved treatment. Periocular route is a promising alternative to the common routes of ocular drug delivery especially for treatment of posterior eye diseases. Based on barriers for efficient drug delivery to the eye, magnetic drug targeting revealed to be influential to eliminate some obstacles of this route which has not been worked before. It is hypothesized that the particles can pulled into the eye or will be trapped inside the sclera tissue or even if it is not happened, they can stay behind the sclera and magnetic force can... 

    Chemical Adjustment of Membrane Surface to Reduce Fouling in Membrane Bioreactors

    , M.Sc. Thesis Sharif University of Technology Vaghar-Mousavi, Danial (Author) ; Bastani, Dariush (Supervisor) ; Mousavi, Abbas (Supervisor)
    Abstract
    In this study, modification of Polyvinylidene fluoride membrane in order to reduce membrane fouling in membrane bioreactors is investiged. To achieve this goal, chemical modification and grafting methods were used. Initially, by chemical modification, the reaction was made to make hydroxyl groups on the membrane surface. The hydroxyl functional groups were used as a site for connecting of subsequent monomers. Finally, the lysozyme enzyme was used as the main modifier to improve the hydrophilicity and antibacterial properties of the membrane surface. To evaluate the performance of the modified membrane in comparison with the pristine membrane, different tests, such as water contact angle... 

    Improvement of performance and fouling resistance of polyamide reverse osmosis membranes using acrylamide and TiO2 nanoparticles under UV irradiation for water desalination

    , Article Journal of Applied Polymer Science ; Volume 137, Issue 11 , 2020 Asadollahi, M ; Bastani, D ; Mousavi, S. A ; Heydari, H ; Vaghar Mousavi, D ; Sharif University of Technology
    John Wiley and Sons Inc  2020
    Abstract
    The purpose of this research is to explain the surface modification of fabricated polyamide reverse osmosis (RO) membranes using UV-initiated graft polymerization at different irradiation times (15, 30, 60, and 90 s) and various acrylamide concentrations (10, 20, and 30 g L−1). Also, coating of membranes surface with various concentrations of TiO2 nanoparticles (10, 20, 30, and 50 ppm) followed by the same UV irradiation times was investigated. After that, the membranes modification was done by grafting of acrylamide blended with TiO2 nanoparticles via UV irradiation. The characterization of membranes surface properties and their performance were systematically carried out. The results... 

    Optimizing Transmisson from Distant Wind Farms

    , M.Sc. Thesis Sharif University of Technology Abdollahi Mansourkhani, Hamid Reza (Author) ; Hosseini, Hamid (Supervisor)
    Abstract
    Wind power is site dependent and is by nature partially dispatchable. Furthermore, good wind sites are far from grid. Due to these problems, and along with the existing limitations in the transmission networks, a comprehensive analysis over an extended time is needed to properly explore all potential wind sites for wind capacity allocation. This problem is computationally expensive and decomposition methods are required to break down this problem. Here Benders decomposition approach is used, which is a popular technique for solving large-scale problems, to decompose the original problem into a master and a subproblem. The master problem is a linear problem, which allocates wind capacity to... 

    General noise considerations of amplified photons in lightwave systems with optically bistable elements

    , Article Proceedings - 10th International Conference on Laser and Fiber-Optical Networks Modeling, LFNM 2010, 12 September 2010 through 14 September 2010 ; 2010 , Pages 93-95 ; 9781424469970 (ISBN) Abediasl, H ; Naqavi, A ; Mehrany, K ; Mousavi, S. M ; Aliakbar, J ; Mousavi, S. M ; Sharif University of Technology
    2010
    Abstract
    An optical amplifier followed by a bistable element has been statistically analyzed before [1]. In this manuscript, output noise analysis represents, then signal to noise ratios (SNR) are calculated either for input or output. It will be shown that noise reduction, can be achieved by a proper selection of parameters  

    Design and assessment of variable-structure LQG PID multivariable controllers

    , Article Optimal Control Applications and Methods ; 2016 ; 01432087 (ISSN) Mousavi, H ; Nobakhti, A ; Sharif University of Technology
    John Wiley and Sons Ltd  2016
    Abstract
    Control Performance Assessment (CPA) and tuning of PID controllers are studied in this paper. We propose a framework for systematic analysis of the tradeoff between the structural complexity of the controller and its performance. As the measure of the controller performance, an LQG based index is used. The problem is augmented with an additional term which forces sparsity on the complexity of a decentralized PID controller. The desired complexity is controlled via a weighting parameter which determines the cost of each additional element (i.e., P, I, and D terms). The result is a decentralized multivariable PID controller in which the complexity of each loop controller is optimized such that... 

    Design and assessment of variable-structure LQG PID multivariable controllers

    , Article Optimal Control Applications and Methods ; Volume 38, Issue 4 , 2017 , Pages 634-652 ; 01432087 (ISSN) Mousavi, H ; Nobakhti, A ; Sharif University of Technology
    John Wiley and Sons Ltd  2017
    Abstract
    Control Performance Assessment (CPA) and tuning of PID controllers are studied in this paper. We propose a framework for systematic analysis of the tradeoff between the structural complexity of the controller and its performance. As the measure of the controller performance, an LQG based index is used. The problem is augmented with an additional term which forces sparsity on the complexity of a decentralized PID controller. The desired complexity is controlled via a weighting parameter which determines the cost of each additional element (i.e., P, I, and D terms). The result is a decentralized multivariable PID controller in which the complexity of each loop controller is optimized such that... 

    Challenges in using peer-to-peer structures in order to design a large-scale web search engine

    , Article 13th International Computer Society of Iran Computer Conference on Advances in Computer Science and Engineering, CSICC 2008, Kish Island, 9 March 2008 through 11 March 2008 ; Volume 6 CCIS , 2008 , Pages 461-468 ; 18650929 (ISSN); 3540899847 (ISBN); 9783540899846 (ISBN) Mousavi, H ; Movaghar, A ; Sharif University of Technology
    2008
    Abstract
    One of the distributed solutions for scaling Web Search Engines (WSEs) may be peer-to-peer (P2P) structures. P2P structures are successfully being used in many systems with lower cost than ordinary distributed solutions. However, the fact that they can also be beneficial for large-scale WSEs is still a controversial subject. In this paper, we introduce challenges in using P2P structures to design a large-scale WSE. Considering different types of P2P systems, we introduce possible P2P models for this purpose. Using some quantitative evaluation, we compare these models from different aspects to find out which one is the best in order to construct a large-scale WSE. Our studies indicate that... 

    Optimized U-shape convolutional neural network with a novel training strategy for segmentation of concrete cracks

    , Article Structural Health Monitoring ; 2022 ; 14759217 (ISSN) Mousavi, M ; Bakhshi, A ; Sharif University of Technology
    SAGE Publications Ltd  2022
    Abstract
    Crack detection is a vital component of structural health monitoring. Several computer vision-based studies have been proposed to conduct crack detection on concrete surfaces, but most cases have difficulties in detecting fine cracks. This study proposes a deep learning-based model for automatic crack detection on the concrete surface. Our proposed model is an encoder–decoder model which uses EfficientNet-B7 as the encoder and U-Net’s modified expansion path as the decoder. To overcome the challenges in the detection of fine cracks, we trained our model with a new training strategy on images extracted from an open-access dataset and achieved a 96.98% F1 score for unseen test data. Moreover,... 

    Optimized U-shape convolutional neural network with a novel training strategy for segmentation of concrete cracks

    , Article Structural Health Monitoring ; Volume 22, Issue 2 , 2023 , Pages 1211-1224 ; 14759217 (ISSN) Mousavi, M ; Bakhshi, A ; Sharif University of Technology
    SAGE Publications Ltd  2023
    Abstract
    Crack detection is a vital component of structural health monitoring. Several computer vision-based studies have been proposed to conduct crack detection on concrete surfaces, but most cases have difficulties in detecting fine cracks. This study proposes a deep learning-based model for automatic crack detection on the concrete surface. Our proposed model is an encoder–decoder model which uses EfficientNet-B7 as the encoder and U-Net’s modified expansion path as the decoder. To overcome the challenges in the detection of fine cracks, we trained our model with a new training strategy on images extracted from an open-access dataset and achieved a 96.98% F1 score for unseen test data. Moreover,... 

    Feasibility And Study(CNG Cylinder Production Plant)

    , M.Sc. Thesis Sharif University of Technology Mousavi, Mohammad (Author) ; Haji, Alireza (Supervisor)
    Abstract
    Nowadays best using of fossil fuels sources of the country (and) importance of comparison against lack of capacity in petrol production make determined the programmers and the directors to foresee and design expanded programs of the goals, to use natural gas for car fuels. To reach fulfillment of these programs, the confirmed needs of the natural gas cylinders are improved and make it essential to invest on producing compressive natural gas cylinders. In this way economical and technical change researches has been done in order to construct on department to produce 200,000 compressive natural gas cylinders in a year during two sets.(shifts) According to the results of technical researches... 

    Numerical Simulation of Forced Impregnation in a Thick Capillary Tube

    , M.Sc. Thesis Sharif University of Technology Safavi, Mohammad (Author) ; Mousavi, Ali (Supervisor)
    Abstract
    Drop penetration into the capillary tube, as a classical problem, has been studied over 100 years. But there are a few studies that investigate forced impregnation of capillary tubes, which has major application in coating, inkjet printing and rain drop penetration into the soil, have been made. A comprehensive numerical investigation on millimeter droplet impact dynamics on a thick capillary tube with micrometer sized pore is conducted and validated against experimental data. This work is extended to oblique impact of drops into pores and normal impact on nanoscaled pores. We apply the finite volume numerical method to solve the time-dependent governing equations of continuity, momentum in... 

    Investigation of Dynamic Response of Shallow Foundations on Layered Soil Medium by Physical Modeling

    , M.Sc. Thesis Sharif University of Technology Mousavi, Mohammad (Author) ; Jafarzadeh, Fardin (Supervisor)
    Abstract
    Dynamic impedance functions method is most recent approach in the analysis of soil-foundation dynamic interaction, and presented for massless rigid foundations. Impedance functions are frequency dependent functions, and used to obtain dynamic response of foundation with arbitrary mass subjected to dynamic loading of any frequency and magnitude. The important assumptions for appropriate useof mentioned method are rigidity of foundation and visco-elastic behavior of the soil beneath the foundation. In this study, experimental vertical impedance functions of square and circular foundations have been investigated,using physical modeling tests. A granular soil layer with finite thickness... 

    Optimal Investment Strategies in Discrete-Time With Access to Derivatives

    , M.Sc. Thesis Sharif University of Technology Mousavi, Reza (Author) ; Kianfar, Farhad (Supervisor)
    Abstract
    Optimal investment strategies are often derived in continuous time models, but have to be implemented in discrete time. It has been shown that in models with stochastic volatility or jumps; this could lead to significant utility loss, for an investor who utilizes ‘Derivatives’ in his/her portfolio. In this study, we determine the optimal investment strategies with discrete trading explicitly taken into account, through ‘Stochastic Dynamic Programming’. These strategies are in the form of optimal factor exposures for portfolio. The investor, then, needs to use sufficient non-redundant Derivatives in addition to the ‘Stock’ to gain the desired exposures in each point of state space he meet.... 

    Design and Implementation of 7-10 GHz CMOS Phase Shifter

    , M.Sc. Thesis Sharif University of Technology Mousavi, Naser (Author) ; Medi, Ali (Supervisor)
    Abstract
    Phased array systems which are used for sending and receiving electromagnetic signals in mandatory directions are widely used in today’s wireless communication, satellite communication, and radar systems. Phased array systems are composed of units called transmitter/ receiver (TR) modules. These units are connected to antennas in one end and to the combiner/divider at the other end and are playing a major role in determining the quality of phased arrays. Transmitter/Receiver units include a phase shifting circuit for controlling the phase and an attenuator circuit for amplitude control of the signal being sent or received, solid state switches and a number of amplifiers. The aim of this...