Loading...
Search for: tehrani-matin--k
0.121 seconds

    Cost Based Comparing of Different Retrofitting Strategies for URM Schools and Choosing the Best Possible One

    , M.Sc. Thesis Sharif University of Technology Mirzai Matin, Danial (Author) ; Kazemi, Mohammad Taghi (Supervisor)
    Abstract
    Among different natural disasters, earthquake has always been known as one of the most effective ones on human lives, and this is only because we still cannot predict the exact time and place of its happening. So, giving special attention to the methods which can omit or minimize the damages of this natural event is needed for controlling the loss in the event of an earthquake. On the other hand schools are known as places which are full of people from younger ages for at least half of each day, and they are considered to be not well educated about how to react in an earthquake in comparison to older people and also considered vulnerable at the time of this natural event. According to what... 

    Hardware Implementation of Spiking Neural Networks

    , M.Sc. Thesis Sharif University of Technology Taji, Hossein (Author) ; Shabany, Mahdi (Supervisor) ; Hashemi, Matin (Co-Supervisor)
    Abstract
    Spiking neural networks (SNNs) are third generation of neural networks. Similar to traditional neural networks, SNNs are comprised neurons. However, not only structure but also information processing is inspired by animal neural systems. SNNs can be called the most similar networks to animal neural systems. In such networks, the information is processed based on propagation of spike signals through the network. The type of data flow in these networks leads to being low-power when they are implemented on hardware. Therefore,there has been a upward trend in hardware implementation of them, like their FPGA implementations, for applications such as Big Data and Machine Learning. In this thesis,... 

    , M.Sc. Thesis Sharif University of Technology Ahangarzadeh, Amir (Author) ; Shabani, Mahdi (Supervisor) ; Hashemi, Matin (Supervisor)
    Abstract
    The application of deep learning algorithms in the processing of telecommunication signals is increasing. One of the issues in this area is the automatic recognition of radio signal modulation. Recognizing the type of signal modulation as the first stage of baseband signal processing on the receiver side is a key issue in military and civilian applications. The problem with classical algorithms for solving this problem is their strong dependence on channel characteristics and factors resulting from the transmitter and receiver being non-ideal. However, modern algorithms based on deep neural networks have been able to make the model somewhat resistant to these factors. However, the detection... 

    Silver fiber fabric as the current collector for preparation of graphene- based supercapacitors

    , Article Electrochimica Acta ; Volume 227 , 2017 , Pages 246-254 ; 00134686 (ISSN) Mehrabi Matin, B ; Shahrokhian, S ; Iraji zad, A ; Sharif University of Technology
    Elsevier Ltd  2017
    Abstract
    During the past few years, a considerable attention has been devoted to the development of textile- based energy storage devices and wearable electronics applications. In this paper, for the first time, we report a flexible high performance graphene-based supercapacitor using silver fiber fabric as the current collector. The silver fiber fabric offers remarkable advantages such as light weight, mechanical flexibility and ease of integration with electronic textiles, which well-suited for wearable energy storage devices. A new hybrid material of graphene-silver fiber fabric (rGO/SFF) was prepared through a facile electrophoretic deposition of graphene and being used as a binder-free flexible... 

    Real-Time Hand Pose Estimation Using Camera Vision System

    , M.Sc. Thesis Sharif University of Technology Kiani, Mahmoud (Author) ; Hashemi, Matin (Supervisor) ; Namvar, Mehrzad (Supervisor)
    Abstract
    Hand pose estimation is something that has applications in many fields, including augmented and virtual reality systems, as well as mixed reality. Hand gesture recognition and classification applications including sign language recognition and non-handheld senarios (such as storefront contactless Survey systems) that have found special cases in the Qovid-19 pandemic period Shows the highest hand pose estimation importance. In our work, we target 2D and 3D estimation at the same time and also use RGB camera as a sensor to record input data. It becomes more economical to achieve Compared with using RGBD or depth sensors . There is only one RGB image in our input. Also there is no contract to... 

    Design of Multi-Object Tracking Algorithms Based on Transformer Models

    , M.Sc. Thesis Sharif University of Technology Ramezan Dehnavi, Mohammad Amin (Author) ; Hashemi, Matin (Supervisor)
    Abstract
    Nowadays, Multi-Object Tracking (MOT) plays a crucial role in various computer vision applications such as autonomous vehicles, surveillance, and robotics. Traditional MOT methods often struggle with challenges such as high errors when dealing with complex scenarios involving occlusion, scale variations, and object interactions. Recent advancements in deep learning, particularly Convolutional Neural Networks (CNNs) and Transformer models, have demonstrated significant capabilities in addressing these challenges. This thesis presents a study on the use of deep learning techniques, specifically CNNs and Transformer models, for solving the problem of Multi-Object Tracking. It begins by... 

    FEM Analysis of the Effects of Geometric Parameters on the Superplastic Forming of Metal Matrix Composit

    , M.Sc. Thesis Sharif University of Technology Tehrani, Mehdi (Author) ; Abedian, Ali (Supervisor)
    Abstract
    In aerospace applications, the weight of structures is considered as a major performance parameter. One of the most effective ways for weight reduction is then attributed to the structurally continuous manufacturing of mechanical components. In this way, not only the weight, but also the stress concentration, the cost, joints and fasteners applications, and the time of manufacturing are noticeably reduced. With this method, components with complicated shapes could be formed in a single manufacturing step. Special specification of whisker reinforced Metal Matrix Composites (MMC’s) has made these materials very attractive for the aerospace applications.That is why the superplastic forming of... 

    Investigation of particle dispersion and deposition in a channel with elliptic obstructions using lattice Boltzmann method

    , Article 2012 7th IEEE International Conference on Nano/Micro Engineered and Molecular Systems, NEMS 2012, 5 March 2012 through 8 March 2012 ; March , 2012 , Pages 523-528 ; 9781467311243 (ISBN) Tehrani, A ; Moosavi, A ; Sharif University of Technology
    2012
    Abstract
    Particle transport and deposition in a channel flow with elliptic obstruction is studied. Numerical simulation of fluid flow is performed using two-dimensional lattice Boltzmann method, while one-way coupling Lagrangian method for particle tracking is used. Standard particles are injected in the inlet of the channel. Gravity, Drag force, Brownian forces, and the Saffman lift are considered in equation of particle motion. The influence of geometrical parameter, ellipse aspect ratio, is studied on dispersion and deposition of particles as well as the flow parameters, such as Reynolds number. In addition, the effect of particles size -particles of 0.01-10μm in diameter- on dispersion and... 

    A fem study of the overlapping ratio effect on superplastic formation of metal matrix composites

    , Article 27th Congress of the International Council of the Aeronautical Sciences 2010, ICAS 2010, 19 September 2010 through 24 September 2010, Nice ; Volume 3 , 2010 , Pages 1836-1843 ; 9781617820496 (ISBN) Tehrani, M ; Abedian, A ; Sharif University of Technology
    2010
    Abstract
    In aerospace applications structures weight is considered as a major performance parameter. One of the most effective manufacturing methods for weight reduction is superplastic forming. By this technique, not only the weight, but also the stress concentration, the cost, and the manufacturing time are noticeably reduced. Additionally, the components with complicated shapes could be formed in a single manufacturing step. Due to the wide demand for whiskers reinforced metal matrix composites (MMCs) in aerospace industries, many research works have been designed to extend the borders of superplastic forming to MMCs materials. In the present study, a 3-D symmetric micromechanical finite element... 

    Integrating constrained random waves in endurance time analysis of offshore structures subjected to sea waves

    , Article Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE, 1 July 2012 through 6 July 2012 ; Volume 2 , July , 2012 , Pages 677-684 ; 9780791844892 (ISBN) Matin Nikoo, H ; Estekanchi, H ; Zeinoddini, M ; Golestani, M ; Sharif University of Technology
    2012
    Abstract
    This paper introduces a novel methodology for design and assessment of offshore structures exposed to irregular sea waves. For this, Constrained NewWave (CNW) is integrated with the Endurance Time Analysis (ETA) methodology, which is basically developed for the performance based analysis of onshore structures to earthquake loads. In this approach, the offshore structure is simulated in time-domain under a set of calibrated intensifying wave functions. They are devised to represent a gradually increasing roughness of the sea state by time. A performance index such as base shear, drift or stress in a critical structural members are monitored until they reach to a predefined maximum value. A... 

    Design and Hardware Implementation of Real-Time Simulator for Electrical Machines

    , M.Sc. Thesis Sharif University of Technology Hadizadeh, Ali (Author) ; Hashemi, Matin (Supervisor) ; Parniani, Mostafa (Co-Advisor)
    Abstract
    Real-time simulators are important in design and test of power systems. Real-time simulators with hardware-in-loop capabilities are used in design of new elements in order to achieve maximum compatibility between subsystems, or in diagnosis and maintenance.The purpose of this dissertation is to design a real-time simulator for electrical machines. For this purpose, a three-phase induction machine is chosen and its model is extracted and discretized. This procedure results in a system of differential equations in form of AX = B. The extracted equations needs to be solved in real-time at every time-step. The real-time algorithms are imple-mented on FPGA. The implemented real-time simulator... 

    Experimental study of flow field on stepped airfoil at very low Reynolds number

    , Article Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering ; Volume 231, Issue 9 , 2017 , Pages 1706-1717 ; 09544100 (ISSN) Kamyab Matin, R ; Ghassemi, H ; Ebrahimi, A ; Ghasemi, B ; Sharif University of Technology
    2017
    Abstract
    In this article, the flow field around NACA0024 airfoil with step at lower and upper surfaces is experimentally investigated. For this purpose, particle image velocimetry technique based on the instantaneous flow structures is used to investigate the flow field around the airfoil at different times. All the experimental measurements in current study are conducted at very low Reynolds number condition based on the chord of the airfoil (Re=2000) and at angles of attack at 0° and 5° where the flow around airfoils is separated. The differences between vortical structures, mean streamlines, sizes of the wake regions, and vortex shedding of the stepped airfoils compared to unmodified airfoil are... 

    Novel dual-loop bi-evaporator vapor compression refrigeration cycles for freezing and air-conditioning applications

    , Article Applied Thermal Engineering ; Volume 138 , 25 June , 2018 , Pages 563-582 ; 13594311 (ISSN) Rostamzadeh, H ; Rostamzadeh, J ; Matin, P. S ; Ghaebi, H ; Sharif University of Technology
    Elsevier Ltd  2018
    Abstract
    Cooling production at different temperature levels for various applications has been highlighted in recent years since the produced cooling capacity must be used for different applications to meet all subjects’ demands. For this purpose, a novel dual-loop bi-evaporator vapor compression refrigeration cycle is proposed to meet these demands for freezing and air-conditioning applications which can be employed in building sectors. Later, ejector expander is used in place of the expansion valve in the proposed refrigeration system to enhance the performance of this basic system based on the thermodynamics and thermoeconomics viewpoints. Four working fluids of R717, R290, R600a, and R134a are... 

    Deep Learning Algorithms for Solving Graph Problems

    , M.Sc. Thesis Sharif University of Technology Bozorg, Mahdi (Author) ; Salehkaleybar, Saber (Supervisor) ; Hashemi, Matin (Co-Supervisor)
    Abstract
    Nowadays, thanks to improvement of processing hardware and plenty of data available, artificial intelligence and specifically Deep Learning are being one of the powerful tools for solving different problems. Also graph is one of the powerful tools for modeling different data structures. Graph matching is one of the problems in the field of graph problems.In this thesis we consider the problem of graph matching in Erdos-Renyi graphs. The graph matching problem refers to recovering the node-to-node correspondence between two correlated graphs. Previous works theoretically showed that recovering is feasible in sparse Erdos-R´enyi graphs if and only if the probability of having an edge between a... 

    Feasibility of imperialist competitive algorithm to predict the surface settlement induced by tunneling

    , Article Engineering with Computers ; 2018 ; 01770667 (ISSN) Tashayo, B ; Behzadafshar, K ; Soltani Tehrani, M ; Afkhami Banayem, H ; Hashemi, M. H ; Taghavi Nezhad, S. S ; Sharif University of Technology
    Springer London  2018
    Abstract
    Surface settlement is considered as an adverse effect induced by tunneling in the civil projects. This paper proposes the use of the imperialist competitive algorithm (ICA) for predicting the maximum surface settlement (MMS) resulting from the tunneling. For this work, three forms of equations, i.e., linear, quadratic and power are developed and their weights are then optimized/updated with the ICA. The requirement datasets were collected from the line No. 2 of Karaj urban railway, in Iran. In the ICA models, vertical to horizontal stress ratio, cohesion and Young’s modulus, as the effective parameters on the MSS, are adopted as the inputs. The statistical performance parameters such as root... 

    Feasibility of imperialist competitive algorithm to predict the surface settlement induced by tunneling

    , Article Engineering with Computers ; Volume 35, Issue 3 , 2019 , Pages 917-923 ; 01770667 (ISSN) Tashayo, B ; Behzadafshar, K ; Soltani Tehrani, M ; Afkhami Banayem, H ; Hashemi, M. H ; Taghavi Nezhad, S. S ; Sharif University of Technology
    Springer London  2019
    Abstract
    Surface settlement is considered as an adverse effect induced by tunneling in the civil projects. This paper proposes the use of the imperialist competitive algorithm (ICA) for predicting the maximum surface settlement (MMS) resulting from the tunneling. For this work, three forms of equations, i.e., linear, quadratic and power are developed and their weights are then optimized/updated with the ICA. The requirement datasets were collected from the line No. 2 of Karaj urban railway, in Iran. In the ICA models, vertical to horizontal stress ratio, cohesion and Young’s modulus, as the effective parameters on the MSS, are adopted as the inputs. The statistical performance parameters such as root... 

    Metabolic profiling of seminal plasma from teratozoospermia patients

    , Article Journal of Pharmaceutical and Biomedical Analysis ; Volume 178 , January , 2020 Mehrparvar, B ; Chashmniam, S ; Nobakht, F ; Amini, M ; Javidi, A ; Minai Tehrani, A ; Arjmand, B ; Gilany, K ; Sharif University of Technology
    Elsevier B. V  2020
    Abstract
    Teratozoospermia is one of conditions that can cause male infertility. The mechanism of teratozoospermia remains unclear. The knowledge of the metabolites in human seminal plasma (HSP) is meaningful for the pathological study of teratozoospermia. Analysis of changed metabolites in HSP can help understand the cellular mechanism, find the novel biomarkers and subsequently design a diagnosis test. In this study, the analysis of samples performed by proton nuclear magnetic resonance spectroscopy (1H NMR spectroscopy) to identify the various metabolites, with the aim of finding metabolic profiles and biomarkers related to male infertility. Eighteen de-regulated metabolites were identified in... 

    Comparison of gas phase intrinsic properties of cytosine and thymine nucleobases with their O-alkyl adducts: Different hydrogen bonding preferences for thymine versus O-alkyl thymine

    , Article Journal of Molecular Modeling ; Volume 19, Issue 8 , 2013 , Pages 2993-3005 ; 16102940 (ISSN) Aliakbar Tehrani, Z ; Fattahi, A ; Sharif University of Technology
    2013
    Abstract
    In recent years, there has been increasing interest in damaged DNA and RNA nucleobases. These damaged nucleobases can cause DNA mutation, resulting in various diseases such as cancer. Alkylating agents are mutagenic and carcinogenic in a variety of prokaryotic and eukaryotic organisms. The present study employs density functional theory (DFT/B3LYP) with the 6-311++G(d,p) basis set to investigate the effect of chemical damage in O-alkyl pyrimidines such as O4-methylthymine, O2-methylcytosine and O 2-methylthymine. We compared the intrinsic properties, such as proton affinities, gas phase acidities, equilibrium tautomerization and nucleobase pair's hydrogen bonding properties, of these... 

    Conformational aspects of glutathione tripeptide: Electron density topological & natural bond orbital analyses

    , Article Structural Chemistry ; Volume 24, Issue 1 , 2013 , Pages 147-158 ; 10400400 (ISSN) Aliakbar Tehrani, Z ; Fattahi, A ; Sharif University of Technology
    2013
    Abstract
    Glutathione tripeptide (γ-glutamyl-cysteinyl-glycine) is a flexible molecule and its conformational energy landscape is strongly influenced by forming intramolecular hydrogen bond, its charge and the environment. This study employs DFT-B3LYP method with the 6-31+G (d,p) basis set to carry out conformational analysis of neutral, zwitterionic, cationic, and anionic forms of glutathione. In analyzing the structural characteristics of these structures, intramolecular hydrogen bonds were identified and characterized in details by topological parameters such as electron density ρ(r) and Laplacian of electron density Δ2 ρ(r) from Bader's atom in molecules theory. Charge transfer energies based on... 

    Bifurcation structure of two coupled FHN neurons with delay

    , Article Mathematical Biosciences ; Volume 270 , 2015 , Pages 41-56 ; 00255564 (ISSN) Farajzadeh Tehrani, N ; Razvan, M ; Sharif University of Technology
    Elsevier Inc  2015
    Abstract
    This paper presents an investigation of the dynamics of two coupled non-identical FitzHugh-Nagumo neurons with delayed synaptic connection. We consider coupling strength and time delay as bifurcation parameters, and try to classify all possible dynamics which is fairly rich. The neural system exhibits a unique rest point or three ones for the different values of coupling strength by employing the pitchfork bifurcation of non-trivial rest point. The asymptotic stability and possible Hopf bifurcations of the trivial rest point are studied by analyzing the corresponding characteristic equation. Homoclinic, fold, and pitchfork bifurcations of limit cycles are found. The delay-dependent stability...