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mohebbi-kalkhoran--hamed
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Pain level estimation in video sequences of face using incorporation of statistical features of frames
, Article 9th Iranian Conference on Machine Vision and Image Processing, 18 November 2015 through 19 November 2015 ; Volume 2016-February , 2015 , Pages 172-175 ; 21666776 (ISSN) ; 9781467385398 (ISBN) ; Fatemizadeh, E ; Sharif University of Technology
IEEE Computer Society
2015
Abstract
Pain level estimation from videos of face has many benefits for clinical applications. Most of the previous works focused only on pain detection task. However, pain level estimation of video sequences has been discussed fewer. In this work, we have proposed a new regression-based approach to estimate the pain level of video sequences. As the first step, facial expression-related features were extracted from each frame, this task was done by reducing identity-related features using the robust principal component analysis decomposition. Then, we used the minimum, maximum, and mean of the features of frames in a sequence to represent that sequence by a fixed-length feature vector. After this,...
Pain Level Estimation Using Facial Expression
, M.Sc. Thesis Sharif University of Technology ; Fatemizadeh, Emad (Supervisor)
Abstract
In this study pain level estimation using facial expression is investigated. To do this, there are two approaches, one approach is sequence level pain estimation and the other one is frame level pain estimation. In sequence level, after feature extraction from all frames of sequence, each sequence is represented by a fixed length feature vector, this feature vector is constructed by concatenating min, max and mean of frame features of that specific sequence, then KLPP is applied in order to reduce feature vector dimension and in the end a linear regression is implemented to predict the pain labels of the sequence. In the frame level, two approaches are introduced, the first one is based on...
Speech Enhancement Using Deep Neural Networks
, M.Sc. Thesis Sharif University of Technology ; Sameti, Hossein (Supervisor)
Abstract
Quality and intelligibility are two aspects of speech that are affected by various factors, such as background noise and echo. The performance of many commercial and military speech-based systems depends on at least one of these aspects of speech. Therefore, this research aims to design an improvement model to remove background noise and reverberation from the speech signal. The model training framework is based on deep learning methods and has a supervised approach in the time domain. The input of this system is the raw waveform of the speech signal mixed with noise and reverberation, and the output is the enhanced waveform of this signal. An architecture is proposed in this thesis based on...
A robust FCM algorithm for image segmentation based on spatial information and total variation
, Article 9th Iranian Conference on Machine Vision and Image Processing, 18 November 2015 through 19 November 2015 ; Volume 2016-February , 2015 , Pages 180-184 ; 21666776 (ISSN) ; 9781467385398 (ISBN) ; Mohebbi Kalkhoran, H. M ; Fatemizadeh, E ; Sharif University of Technology
IEEE Computer Society
2015
Abstract
Image segmentation with clustering approach is widely used in biomedical application. Fuzzy c-means (FCM) clustering is able to preserve the information between tissues in image, but not taking spatial information into account, makes segmentation results of the standard FCM sensitive to noise. To overcome the above shortcoming, a modified FCM algorithm for MRI brain image segmentation is presented in this paper. The algorithm is realized by incorporating the spatial neighborhood information into the standard FCM algorithm and modifying the membership weighting of each cluster by smoothing it by Total Variation (TV) denoising. The proposed algorithm is evaluated with accuracy index in...
Preparation of Cobalt and Manganese Salts of Para-amino Benzoic Acid Supported on Graphene Oxide as an Oxidative Nanocatalysts
, M.Sc. Thesis Sharif University of Technology ; Mahmoodi Hashemi, Mohammad (Supervisor)
Abstract
In this thesis, a heterogeneous nanocatalyst based on graphene oxide was synthesized. To improve the graphene oxide, it was reacted with paraaminobenzoic acid and then metal salts (cobalt and manganese) were coated on it. The structure of the catalyst was confirmed by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), quantitative X-ray diffraction (EDS) and infrared (FT-IR) spectroscopy. Finally, the catalytic properties of the catalysts were evaluated in the oxidation reaction of different alcohols in the presence of oxygen. In the presence of benzyl alcohols with lethal electron groups, the oxidation conditions are stricter and the reaction efficiency is lower....
Designing optimal tuned mass dampers for nonlinear frames by distributed genetic algorithms
, Article Structural Design of Tall and Special Buildings ; Volume 21, Issue 1 , 2012 , Pages 57-76 ; 15417794 (ISSN) ; Joghataie, A ; Sharif University of Technology
2012
Abstract
In this paper, the capabilities of tuned mass dampers (TMDs) for the mitigation of response of nonlinear frame structures subjected to earthquakes have been studied. To determine the optimal parameters of a TMD, including its mass, stiffness and damping, we developed an optimization algorithm based on the minimization of a performance index, defined as a function of the response of the nonlinear structure to be controlled. Distributed genetic algorithm has been used to solve the optimization problem. For illustration, the method has been applied to the design of a linear TMD for an eight-story nonlinear shear building with bilinear hysteretic material behavior subjected to earthquake. The...
Optimal TMDs for improving the seismic performance of historical buildings
, Article Scientia Iranica ; Volume 23, Issue 1 , 2016 , Pages 79-90 ; 10263098 (ISSN) ; Joghataie, A ; Sharif University of Technology
Sharif University of Technology
2016
Abstract
In this paper, optimal design and assessment of the capability of Tuned Mass Dampers (TMDs) in improving the seismic behavior of Confined masonry walls, as the main element of historical buildings, has been studied. For this purpose, the design parameters of TMDs have been determined through minimization of wall response using Genetic Algorithms (GAs). To simulate the behavior of Confined masonry wall under earthquake, the triple linear shear beam model has been used. For illustration, the method has been tested on Confined masonry walls equipped with linear TMDs. To study the effects of frequency content and Peak Ground Acceleration (PGA) of earthquake records on the performance of TMDs,...
Continual Learning Using Unsupervised Data
, M.Sc. Thesis Sharif University of Technology ; Soleymani Baghshah, Mahdieh (Supervisor)
Abstract
The existing continual learning methods are mainly focused on fully-supervised scenarios and are still not able to take advantage of unlabeled data available in the environment. Some recent works tried to investigate semi-supervised continual learning (SSCL) settings in which the unlabeled data are available, but it is only from the same distribution as the labeled data. This assumption is still not general enough for real-world applications and restricts the utilization of unsupervised data. In this work, we introduce Open-Set Semi-Supervised Continual Learning (OSSCL), a more realistic semi-supervised continual learning setting in which out-of-distribution (OoD) unlabeled samples in the...
Prediction of formability of tailor welded blanks by modification of MK model
, Article International Journal of Mechanical Sciences ; Volume 61, Issue 1 , 2012 , Pages 44-51 ; 00207403 (ISSN) ; Akbarzadeh, A ; Sharif University of Technology
2012
Abstract
A new model is proposed to predict the Forming Limit Diagrams (FLDs) of Tailor Welded Blanks (TWBs). This model is derived by modification of the Marciniak and Kuczynski (MK) analysis and imposing the weld constraints to deformation state of each blank at each strain increment. Based on this model, it is possible to predict the strains of both weaker and stronger blanks once necking occurs. By comparison to the experimental results of two laser welded TWBs, it is demonstrated that this model provides a close prediction of FLD of TWBs, when necking occurs far from the weld line at a region out of HAZ (Heat Affected Zone) and close to it so that it is affected by the weld line constraints
Fabrication of copper/aluminum composite tubes by spin-bonding process: Experiments and modeling
, Article International Journal of Advanced Manufacturing Technology ; Volume 54, Issue 9-12 , November , 2011 , Pages 1043-1055 ; 02683768 (ISSN) ; Akbarzadeh, A ; Sharif University of Technology
2011
Abstract
The aim of this work is to produce two layered thin-walled Cu/Al composite tube by the spin-bonding process. The process is utilized to bond the aluminum tube into the copper one at thickness reductions of 20-60% and process temperatures of 25°C, 130°C, and 230°C. The bond strength is measured by T-peeling test, and the bond interfaces are examined by metallography and scanning electron microscopy (SEM). The results show that after a threshold thickness reduction of about 30%, the bond strength increased with the amount of deformation. SEM fractography of the peel surfaces confirms that the copper oxide film is broken in a shear manner during deformation. Severe shear strains applied during...
Accumulative spin-bonding (ASB) as a novel SPD process for fabrication of nanostructured tubes
, Article Materials Science and Engineering A ; Volume 528, Issue 1 , November , 2010 , Pages 180-188 ; 09215093 (ISSN) ; Akbarzadeh, A ; Sharif University of Technology
2010
Abstract
A novel SPD process for manufacturing of high strength tubes and cylinders by accumulative spin-bonding (ASB) is proposed. It is demonstrated that due to incremental deformation in this process, high strain rate without considerable temperature rise is achieved. This is accompanied with a high value of Zener-Hollomon parameter as a characteristic of this SPD process. ASB was applied to a commercially pure aluminum up to four cycles and its effects on the microstructure and mechanical properties were examined by optical microscopy, TEM, EBSD, microhardness and tension tests. The results show that ultra-fine grains are developed during the process by formation of subgrains at early stages...
A novel spin-bonding process for manufacturing multilayered clad tubes
, Article Journal of Materials Processing Technology ; Volume 210, Issue 3 , 2010 , Pages 510-517 ; 09240136 (ISSN) ; Akbarzadeh, A ; Sharif University of Technology
2010
Abstract
Utilizing the so-called tube spinning, a cold-bonding process entitled as "spin-bonding" is developed to produce seamless thin-walled clad tubes and cylinders. By this method, two layers of AA 1050 tubes were successfully bonded together to form a clad tube at room temperature. Based on mechanical aspects of the tube spinning process, the mechanism of spin-bonding is explained in two stages: surface preparation before occurrence of a stable bond and bond strengthening thereafter. The effects of process temperature, thickness reduction, feed rate and roller attack angle as the parameters of tube spinning on the bond strength are studied. It is shown that the bond strength increases by...
Constitutive equation and FEM analysis of incremental cryo-rolling of UFG AA 1050 and AA 5052
, Article Journal of Materials Processing Technology ; Volume 255 , 2018 , Pages 35-46 ; 09240136 (ISSN) ; Akbarzadeh, A ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
In this study, ultrafine grained aluminum sheets AA1050 and AA5052 are incrementally cryo-rolled after precooling in liquid nitrogen. Cryogenic deformation is considered as an effective approach to postpone saturation of the grain refinement by conventional severe plastic deformation. However, for a quantitative understanding of the resulted microstructure and mechanical properties, accurate values of the deformation parameters (strain, strain rate and temperature) are needed. The aim of this study is, therefore, to find values of the applied cryo-rolling parameters. As the experimental measurements of parameters such as temperature are infeasible in the thin specimens, a FEM simulation is...
Development of equations for strain rate sensitivity of UFG aluminum as a function of strain rate
, Article International Journal of Plasticity ; Volume 90 , 2017 , Pages 167-176 ; 07496419 (ISSN) ; Akbarzadeh, A ; Sharif University of Technology
2017
Abstract
Strain rate sensitivity (m-value) of ultrafine grain (UFG) AA 1050 and AA 5052 sheets processed by accumulative roll-bonding is investigated versus strain rate by stress relaxation (SR) test at ambient temperature. The results show a weak viscous nature of deformation for AA 5052 specimens as compared to AA 1050 ones. So that much less stress relaxation and negligible strain rate sensitivity are obtained for this material due to dislocation and grain boundary mobility limitation caused by Mg solute atoms. In order to formulate strain rate sensitivity of UFG aluminum as a function of strain rate, three phenomenological and two empirical models are developed and assessed by the experimental...
An efficient tabu search algorithm for the single row facility location problem [electronic resource]
, Article European Journal Of Operational Research ; Vol. 205, No. 1, pp. 98-105 ; Eshghi, Kourosh ; Sharif University of Technology
Abstract
The general goal of the facility layout problem is to arrange a given number of facilities to minimize the total cost associated with the known or projected interactions between them. One of the special classes of the facility layout problem is the Single Row Facility Layout Problem (SRFLP), which consists of finding an optimal linear placement of rectangular facilities with varying dimensions on a straight line. This paper first presents and proves a theorem to find the optimal solution of a special case of SRFLP. The results obtained by this theorem prove to be very useful in reducing the computational efforts when a new algorithm based on tabu search for the SRFLP is proposed in this...
Sensitivity analysis of matching pennies game [electronic resource]
, Article Mathematical and Computer Modelling ; Volume 51, Issues 5–6, March 2010, Pages 722–735 ; Eshghi, Kourosh ; Sharif University of Technology
Abstract
In this paper, we have discussed the results of sensitivity analysis in a payoff matrix of the Matching Pennies game. After representing the game as a LP model, the sensitivity analysis of the elements of the payoff matrix is presented. The game value and the optimal strategies for different values of parameters are determined and compared
Kinetic Study of Partial Oxidation of Methane in Non-Catalytic Porous Media
, M.Sc. Thesis Sharif University of Technology ; Fotovat, Farzam (Supervisor) ; Soltanieh, Mohammad (Supervisor)
Abstract
Partial oxidation of methane (POX) is one of the most common processes to produce synthesis gas. In this study the kinetics of this process is examined and some reduced mechanisms are introduced to model it in this study. The experimental data from Research Institute of Petroleum Industry are used as reference experimental data. Inlets of this reactor are oxygen and methane with equivalence ratio between 2.53 and 2.9. Moreover, the experimental results of previous studies with the air as the oxidant in equivalence ration between 2.4 and 2.6 are used as basis for comparison of simulation results. During the first step, partial oxidation of methane in non-catalytic porous media is simulated by...
Higher prevalence of asymptomatic or mild COVID-19 in children, claims and clues
, Article Journal of Medical Virology ; Volume 92, Issue 11 , May , 2020 , Pages 2257-2259 ; Noorbakhsh, F ; Mohebbi, S. R ; Ghaemi, A
John Wiley and Sons Inc
2020
Hysteretic response of confined masonry walls by Prandtl neural networks
, Article 1st International Conference on Advances and Trends in Engineering Materials and their Applications, AES-ATEMA'2007, Montreal, QC, 6 August 2007 through 10 August 2007 ; 2007 , Pages 525-533 ; 19243642 (ISSN) ; 0978047907 (ISBN); 9780978047900 (ISBN) ; Farrokh, M ; Mohebbi, M ; Sharif University of Technology
2007
Abstract
In this paper a new method of modeling shear force-displacement relationship for confined masonry walls by neural networks has been presented. Although the mathematical models have been very useful in the simulations so far, however developing more accurate models is necessary. While developing precise mathematical models for highly hysteretic materials is itself challenging and practically cumbersome, the use of learning algorithms is an attractive alternative. The issue of material modeling by neural networks has been a challenging one itself, noticing available neural networks have some limitations in the learning of non-linearity. In this paper a new type neural network, called Prandtl...
Peak Temperature Recduction in 3D NoCs using Task Migration
, M.Sc. Thesis Sharif University of Technology ; Hessabi, Shaahin (Supervisor)
Abstract
Combination of 3D stacking and network-on-chip (NoC), known as 3D NoC, has some advantages such as reduced propagation delay, chip area and interconnect, and power consumption, and bandwidth increase. Despite these advantages, the increased power density per chip area due to area decrease causes thermal problems in 3D NoCs to be more critical than 2D NoCs. Therefore, design of temperature management algorithms is essential for these systems. One of the dynamic thermal management techniques is task migration that balances generated thermal among cores.In this thesis, we propose a task migration scheme using feedback control for 3D NoCs. The main purpose of this scheme is to decrease the peak...