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aghababaei-harandi--ali
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Deepfake Videos Detection through Deep Analysis of Artifacts of Images
, M.Sc. Thesis Sharif University of Technology ; Ghaemmaghami, Shahrokh (Supervisor) ; Eghlidos, Taraneh (Supervisor)
Abstract
DeepFake is a type of forgery that uses deep learning algorithms to make changes to audio and video content that the audience is unable to detect. Nowadays, due to the threats posed by the use of DeepFake to move people's faces in video, researchers' attention has been drawn to designing methods to detect this type of forgery. Detection methods are usually classified into two types. The first case is the extraction of features to detect forgery distortions, for example, the extraction of facial orientations to detect inconsistencies. The second case is the use of deep learning networks for feature extraction and classification, of which the EfficientNet network is an example. Despite the...
Designing an Emotion Capturing System Using Eeg Signals and Human-obot Interaction Platform Based on the Captured Emotion
, M.Sc. Thesis Sharif University of Technology ; Taheri, Alireza (Supervisor) ; Meghdari, Ali (Supervisor) ; Ghazizadeh, Ali (Co-Supervisor)
Abstract
Emotions are one of the most important issues which affects daily life and activities. On the other hand, robots play an increasing role in human life and play a fundamental role in meeting our needs. One of these basic roles is empathy and verbal interaction between the robot and human. In this research, participant's emotions were stimulated in two ways: by using OASIS and GAPED image data sets and by instructing the participants to remind about their good or bad memories. During emotional stimulation, EEG signals have been recorded for the training and testing process. The preprocessing of training data includes filtering, removing bad parts of data, removing bad channels and...
Detailed seismic risk analysis of buildings using structural reliability methods
, Article Probabilistic Engineering Mechanics ; Volume 53 , 2018 , Pages 23-38 ; 02668920 (ISSN) ; Mahsuli, M ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
This paper presents probabilistic models and methods for detailed seismic risk analysis of structures using structural reliability methods. This approach to risk analysis is an alternative to those that employ the theorem of total probability and conditional probability distributions. Detailed risk analysis entails probabilistic quantification of responses, the ensuing damage of individual structural and nonstructural components, and the resulting economic and social losses. Such an analysis requires a library of probabilistic models for hazards, responses, damage, repair cost, downtime, and casualty with a specific format as presented in this paper. Two analysis options are proposed: one...
Component damage models for detailed seismic risk analysis using structural reliability methods
, Article Structural Safety ; Volume 76 , 2019 , Pages 108-122 ; 01674730 (ISSN) ; Mahsuli, M ; Sharif University of Technology
Elsevier B.V
2019
Abstract
A probabilistic approach to modeling the seismic damage incurred by structural and nonstructural components is developed in this study. The resulting models are intended for use in detailed risk analysis of structures through structural reliability methods. The proposed modeling approach employs Bayesian linear regression to characterize the epistemic uncertainty in the model. In this approach, regressors are selected and constructed based on the mechanics of damage. In turn, the probability distributions of the model parameters and the model error are quantified by Bayesian linear regression using real-life data from laboratory experiments and/or post-earthquake inspections of damaged...
Component damage models for detailed seismic risk analysis using structural reliability methods
, Article Structural Safety ; Volume 76 , 2019 , Pages 108-122 ; 01674730 (ISSN) ; Mahsuli, M ; Sharif University of Technology
Elsevier B.V
2019
Abstract
A probabilistic approach to modeling the seismic damage incurred by structural and nonstructural components is developed in this study. The resulting models are intended for use in detailed risk analysis of structures through structural reliability methods. The proposed modeling approach employs Bayesian linear regression to characterize the epistemic uncertainty in the model. In this approach, regressors are selected and constructed based on the mechanics of damage. In turn, the probability distributions of the model parameters and the model error are quantified by Bayesian linear regression using real-life data from laboratory experiments and/or post-earthquake inspections of damaged...
Optimizing Commercial Scheduling on TV Channels: Mathematical Model and Metaheuristic Algorithms
, M.Sc. Thesis Sharif University of Technology ; Varmazyar, Mohsen (Supervisor)
Abstract
This thesis investigates the scheduling of television advertisements, which is critical for optimizing the efficiency and profitability of marketing campaigns for TV networks. Since its inception in the 1930s, television has been a cornerstone of advertising, enabling businesses to reach broad and diverse audiences. The evolution of TV advertising strategies, particularly with the rise of digital media competition, underscores the importance of effective advertisement scheduling to maintain relevance and effectiveness. To address this challenge, a comprehensive mixed-integer linear programming (MILP) model was developed. This model incorporates various hypotheses to manage real-world...
Probabilistic Damage Models for Detailed Risk Analysis of Buildings with Reliability Methods
, M.Sc. Thesis Sharif University of Technology ; Mahsuli, Mojtaba (Supervisor)
Abstract
A probabilistic approach to modeling the seismic damage incurred by structural and nonstructural components is developed in this study. For this purpose, Bayesian linear regression is employed to characterize the epistemic uncertainty in the model. In this approach, regressors are constructed based on the mechanics of damage. In turn, the probability distributions of the model parameters and the model error are quantified by Bayesian regression using real-life data from laboratory experiments and/or post-earthquake inspections of damaged components. The study presents the stepwise procedure of collecting the observations, quantifying the repair costs, developing model forms, performing model...
Design and Implementation of Nonsmooth Controller for Mechanical Systems under Nonholonomic Constraint
, M.Sc. Thesis Sharif University of Technology ; Namvar, Mehrzad (Supervisor)
Abstract
This thesis works on certain type of underactuated mechanical systems with nonholonomic constrain, namely wheeled robots.Since this robots has different types, this work focuses specifically on three-wheeled robot. At first we know kinematic characteristics of robot system and equations of motion.To control this system, at first we will change equations to chain form, then control it by using known methods. It will be shown that between the known methods for convergence to a fixed point,irregular transformation is the best way for control systems in chain form.Also, with dynamic feedback linearization we can control robot on a trajectory that has a continuous third order derivatives. Then...
Rigidity of Minimal Submanifolds in Hyperbolic Space
, M.Sc. Thesis Sharif University of Technology ; Ranjbar Motlagh, Alireza (Supervisor)
Abstract
We prove that if an n-dimensional complete minimal submanifold M in hyperbolic space has sufficiently small total scalar curvature then M has only one end. We also prove that for such M there exist no nontrivial L^2 harmonic 1-forms on M
Antimicrobial wound dressing containing silver sulfadiazine with high biocompatibility: In vitro study
, Article Artificial Organs ; Volume 40, Issue 8 , 2016 , Pages 765-773 ; 0160564X (ISSN) ; Shamloo, A ; Aghababaei, Z ; Vossoughi, M ; Moravvej, H ; Sharif University of Technology
Blackwell Publishing Inc
2016
Abstract
Many patients all over the world suffer from acute wounds caused by traumas or burns. In most crucial cases, skin regeneration cannot be promoted spontaneously, and skin grafts are applied as the main treatment. However, this therapy has some drawbacks which motivate researchers to develop wound dressings. In this study, electrospun mats consisting of polycaprolactone (PCL) and polyvinyl alcohol (PVA) incorporated with silver sulfadiazine (SSD) are proposed to be used as antimicrobial wound dressings with the capability of cell seeding. Various amounts of SSD were loaded into PVA nanofibers, and the effects of SSD particles on the morphological characteristics of nanofibers, mechanical...
Stabilization of robots with actuator constraints via interconnection and damping assignment
, Article IEEE Transactions on Control Systems Technology ; Volume 31, Issue 6 , 2023 , Pages 2945-2952 ; 10636536 (ISSN) ; Namvar, M ; Dokht Taghirad, H. R ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2023
Abstract
Actuator limitations hinder high-performance control of robotic manipulators. The problem is particularly challenging in case of underactuated robots where the issue has received less attention. In this brief, we investigate stabilization of manipulators under input constraints via total energy shaping. For this purpose, we use interconnection and damping assignment passivity-based control (IDA-PBC) together with an optimization technique to keep actuator torque close to allowable limits. Using a subsequent technique, the actuator torques are ensured to stay within the specified bounds for special classes of manipulators. The results are verified through simulations on a 2 degree-of-freedom...
, M.Sc. Thesis Sharif University of Technology ; Shojaei, Akbar (Supervisor) ; Bagheri, Reza (Supervisor)
Abstract
Taghizadeh Manzari, M. (MehrdadThe main goals of this project are studding the effect of carbon nanotube on the properties of PA6/PA66 matrix and miscibility of PA6/PA66 blend. So PA6/PA66/CNT nanocomposites were compounded by melt mixing method and samples were prepared by injection molding. Due to study miscibility of PA6 and PA66, we used DMTA test and found that PA6 and PA66 are miscible because of existing one pick on DMTA graph. Also DSC test results confirmed that PA6 and PA66 are miscible. Moreover, according to DMTA results, modulus will be rose by increasing CNT content. Mechanical test showed same results in this case. Adding 1%CNT to matrix caused 10% improvement in modulus and...
Analysis and Design of Analog Operators Based on Photonic Metasurfaces
, M.Sc. Thesis Sharif University of Technology ; Khavasi, Amin (Supervisor) ; Rejaei, Behzad (Co-Advisor)
Abstract
Optical computing has emerged as a promising candidate for real-ime and parallel continuous data processing. Optical devices that perform spatial and spatiotemporal transformations of optical signals are of great interest for a wide range of applications including ultrafast all-optical information processing and analog optical computations. Although plasmonic metasurfaces(for analog computing applications) was investigated in the past, they are not realizable. Consequently the silicon photonics is a good alternative for realizing these applications.Firstly, the optical computing and its important features explained and a common architecture was introduced. in addition, another two structures...
Morphological and mechanical properties of styrene butadiene rubber/nano copper nanocomposites
, Article Results in Physics ; Volume 7 , 2017 , Pages 338-344 ; 22113797 (ISSN) ; Alimoradi, F ; Rowshan, G ; Faghihi, M ; Keivani, M ; Abadyan, M ; Sharif University of Technology
Elsevier B.V
2017
Abstract
In this research, rubber based nanocomposites with presence of nanoparticle has been studied. Styrene butadiene rubber (SBR)/nanocopper (NC) composites were prepared using two-roll mill method. Transmission electron microscope (TEM) and scanning electron microscope (SEM) images showed proper dispersion of NC in the SBR matrix without substantial agglomeration of nanoparticles. To evaluate the curing properties of nanocomposite samples, swelling and cure rheometric tests were conducted. Moreover, the rheological studies were carried out over a range of shear rates. The effect of NC particles was examined on the thermal behavior of the SBR using thermal gravimetric analysis (TGA). Furthermore,...
Effects of soft marine fouling on wave-induced forces in floating aquaculture cages: Physical model testing under regular waves
, Article Ocean Engineering ; Volume 238 , 2021 ; 00298018 (ISSN) ; Zeinoddini, M ; Aalami Harandi, M. M ; Abi, F. A ; Jadidi, P ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Previous experiments on the fouling/current and fouling/wave interactions were mostly limited to two dimensional (2D) net panels or isolated twines. The current paper deals with the wave-induced forces/moments in three dimensional (3D) physical models of a gravity net-cage. The colonial hydroid Ectopleura larynx, a common fouling organism in the aquaculture industry, was artificially modelled and considered in the current experiments. A clean cage and cages with different fouling lengths were tested under deep-water regular wave trains. The time series of the wave-induced forces/moments in the surge, sway, roll and pitch degrees of freedom were recorded and analysed. The experimental results...
Conditional Injective Flows for Bayesian Imaging
, Article IEEE Transactions on Computational Imaging ; Volume 9 , 2023 , Pages 224-237 ; 25730436 (ISSN) ; Kothari, K ; Salsi, L ; Harandi, A. A ; De Hoop, M ; Dokmanic, I ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2023
Abstract
Most deep learning models for computational imaging regress a single reconstructed image. In practice, however, ill-posedness, nonlinearity, model mismatch, and noise often conspire to make such point estimates misleading or insufficient. The Bayesian approach models images and (noisy) measurements as jointly distributed random vectors and aims to approximate the posterior distribution of unknowns. Recent variational inference methods based on conditional normalizing flows are a promising alternative to traditional MCMC methods, but they come with drawbacks: excessive memory and compute demands for moderate to high resolution images and underwhelming performance on hard nonlinear problems....
Technical English for mechanical engineers
, Book ; Meghdari,Ali
Sharif University Press
2014
Abstract
Local educational institutions produce in-house English for Specific Purpose (ESP) materials according to the curriculum policies designated and developed by the Ministry of Higher Education In Iran. To this end, this book aims to be used in the Iranian setting at the tertiary level for undergraduate students majoring in Mechanical Engineering. Moreover, the style of English usage in this ESP textbook is American.
Regarding the content of the textbook, it has both thematic organizations in which the topics are relevant and includes sufficient treatment of the target language areas necessary for the students. The principle organizing approach of this textbook is theme-based. In addition,...
Regarding the content of the textbook, it has both thematic organizations in which the topics are relevant and includes sufficient treatment of the target language areas necessary for the students. The principle organizing approach of this textbook is theme-based. In addition,...
EEG artifact removal using sub-space decomposition, nonlinear dynamics, stationary wavelet transform and machine learning algorithms
, Article Frontiers in Physiology ; Volume 13 , 2022 ; 1664042X (ISSN) ; Tahvilian, P ; Nasirpour, M. H ; Maghooli, K ; Sadeghniiat Haghighi, K ; Vahid Harandi, S ; Abdollahi, Z ; Ghazizadeh, A ; Jafarnia Dabanloo, N ; Sharif University of Technology
Frontiers Media S.A
2022
Abstract
Blind source separation (BSS) methods have received a great deal of attention in electroencephalogram (EEG) artifact elimination as they are routine and standard signal processing tools to remove artifacts and reserve desired neural information. On the other hand, a classifier should follow BSS methods to automatically identify artifactual sources and remove them in the following steps. In addition, removing all detected artifactual components leads to loss of information since some desired information related to neural activity leaks to these sources. So, an approach should be employed to detect and suppress the artifacts and reserve neural activity. This study introduces a novel method...
Feedback control of the neuro-musculoskeletal system in a forward dynamics simulation of stair locomotion [electronic resource]
, Article Proc. of IMechE Part H: Journal of Engineering in Medicine ; 2009, Vol. 223, No. 6, pp. 663-675 Journal of NeuroEngineering and Rehabilitation ; Volume 11, Issue 1, 30 April 2014, Article number 78 ; Meghdari, Ali ; Vossough, Gholam Reza ; Sharif University of Technology
Abstract
The aim of this study is to employ feedback control loops to provide a stable forward dynamics simulation of human movement under repeated position constraint conditions in the environment, particularly during stair climbing. A ten-degrees-of-freedom skeletal model containing 18 Hill-type musculotendon actuators per leg was employed to simulate the model in the sagittal plane. The postural tracking and obstacle avoidance were provided by the proportional—integral—derivative controller according to the modulation of the time rate change of the joint kinematics. The stability of the model was maintained by controlling the velocity of the body's centre of mass according to the desired centre of...
Design and Construction of a Soft Actuated Exoskeleton for Hand Rehabilitation of Stroke Patients
, M.Sc. Thesis Sharif University of Technology ; Ghafari, Ali (Supervisor) ; Meghdari, Ali (Supervisor)
Abstract
The main goal of this thesis is the design and development of a rehabilitation device for helping patients “to improve blood circulation” & retain and recover their abilities if possible that were lost during the stroke or a accident like that (my research in karaj/iran shows that it is possible by just movement of the specific body part). The focus is on hand in this thesis because Injuries to the hand are common and can be very debilitating since our hands are our primary means for interacting with our world. For rehabilitation in case of human hand there are several practices that should be done for patients either in home or in a rehabilitation center, time and money that is supposed to...