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    Continual Learning Using Unsupervised Data

    , M.Sc. Thesis Sharif University of Technology Ameli Kalkhoran, Amir Hossein (Author) ; 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... 

    Secure deep-JSCC against multiple eavesdroppers

    , Article Proceedings - IEEE Global Communications Conference, GLOBECOM ; 2023 , Pages 3433-3438 ; 23340983 (ISSN); 979-835031090-0 (ISBN) Ameli Kalkhoran, S. A ; Letafati, M ; Erdemir, E ; Khalaj, B. H ; Behroozi, H ; Gündüz, D ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2023
    Abstract
    In this paper, a generalization of deep learning-aided joint source channel coding (Deep-JSCC) approach to secure communications is studied. We propose an end-to-end (E2E) learning-based approach for secure communication against multiple eavesdroppers over complex-valued fading channels. Both scenarios of colluding and non-colluding eavesdroppers are studied. For the colluding strategy, eavesdroppers share their logits to collaboratively infer private attributes based on ensemble learning method, while for the non-colluding setup they act alone. The goal is to prevent eavesdroppers from inferring private (sensitive) information about the transmitted images, while delivering the images to a... 

    Modeling interfacial tension of normal alkane-supercritical CO2 systems: Application to gas injection processes

    , Article Fuel ; Volume 253 , 2019 , Pages 1436-1445 ; 00162361 (ISSN) Ameli, F ; Hemmati Sarapardeh, A ; Tatar, A ; Zanganeh, A ; Ayatollahi, S ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    To study the gas injection scenario for successful implementation of enhanced oil recovery (EOR)processes, the prediction of interfacial tension (IFT)between injected gas and the crude oil is of paramount significance. In the present study, some intelligent methods were developed for determining IFT values between supercritical CO2 and normal alkanes. IFT was considered as a function of temperature, pressure, and molecular weight of normal alkanes. The developed methods were Multilayer perceptron (MLP), Genetic Algorithm Radial Basis Function (GA-RBF), and Conjugate Hybrid-PSO ANFIS (CHPSO-ANFIS). The average absolute percent relative errors (AAREs)for the stated techniques were found to be... 

    Iranian national olympiad in informatics

    , Article International Conference Joint with the 29th International Olympiad in Informatics, IOI 2017, 28 July 2017 through 4 August 2017 ; Volume 11, Issue Special Issue , 2017 , Pages 25-33 ; 18227732 (ISSN) Abam, M. A ; Asadi, A ; Jabal Ameli, A ; Seddighin, S. R ; Shahmohammadi, F ; Sharif University of Technology
    Vilnius University  2017

    Designing an Automated and Smart Electric Power Distribution System

    , M.Sc. Thesis Sharif University of Technology Ameli, Amir (Author) ; Vakilian, Mehdi (Supervisor)
    Abstract
    Feeder reconfiguration is one of the most prominent tasks for loss reduction, reliability improvement and also congestion alleviation in distribution networks. Besides improving abovementioned operational issues, during a long period of time, proper switching in appropriate times can causes a lot of economic savings. Furthermore, it can be intensified when capacitors are implemented and controlled in the network. To reach this purpose, most of the previous literature focuses merely on the power grid reconfiguration. Few of these researches have considered this problem as a dynamic one and studied that in a period of time, e.g. one day, considering fixed level of loads despite the others that... 

    Proposing a Control Strategy for Treatment of Hepatitis C Disease

    , M.Sc. Thesis Sharif University of Technology Ameli, Mahyar (Author) ; Shahrokhi, Mohammad (Supervisor)
    Abstract
    Due to the importance of hepatitis disease, especially hepatitis C, from public health view point, this research aims to investigate and suggest an efficient medical therapy for this disease. First, available models are analyzed and the suitable one is chosen. Three controllers namely, fixed PI, adaptive PI and exact linearization control (GLC) are designed to control the hepatitis C disease using the drug efficacy as the manipulated variabel. Controller parameters are determined by the Genetic Algorithm (GA) and their performances are evaluated using the selected model. Uncertainties have been considerd in both model structure and parameters and controllers performances are investigated in... 

    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) Mohebbi Kalkhoran, H ; 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,... 

    A parametric study on residual stresses and forging load in cold radial forging process

    , Article International Journal of Advanced Manufacturing Technology ; Volume 33, Issue 1-2 , 2007 , Pages 7-17 ; 02683768 (ISSN) Ameli, A ; Movahhedy, M. R ; Sharif University of Technology
    2007
    Abstract
    In this work, a comprehensive study of radial forging process is presented through 2-D axisymmetric and 3-D finite element simulations while considering internal tube profile. The tube used in this investigation has four internal helical grooves along its length. The material is modeled with the elastic-plastic behavior, and sliding-sticking friction model is utilized to model the die-workpiece and mandrel-workpiece contacts. The numerical results in the 2-D case are compared with available experimental data. Residual stresses in the forged product, stress concentration around the grooves, pressure distribution on the hammers and mandrel and maximum forging load are studied. The effects of... 

    Speech Enhancement Using Deep Neural Networks

    , M.Sc. Thesis Sharif University of Technology Mohammadian Kalkhoran, Parisa (Author) ; 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 Lightweight Deep Learning Model for Online Network Traffic

    , M.Sc. Thesis Sharif University of Technology Ameli, Ahmad Reza (Author) ; Jalili, Rasool (Supervisor)
    Abstract
    Traffic classification is crucial for the execution of many security and managerial tasks in a network, such as identifying malicious data, detecting disruptive users, and preventing the passage of traffic from certain applications. Nowadays, a significant portion of traffic in computer networks is encrypted. Therefore, the classification of encrypted traffic requires the use of solutions for analyzing encrypted traffic. In recent years, many solutions based on machine learning and deep learning have been proposed for analyzing encrypted traffic. While most of these solutions focus on improving the accuracy of network traffic classification, less attention has been paid to their... 

    Pain Level Estimation Using Facial Expression

    , M.Sc. Thesis Sharif University of Technology Mohebbi Kalkhoran, Hamed (Author) ; 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... 

    A dynamic method for feeder reconfiguration and capacitor switching in smart distribution systems

    , Article International Journal of Electrical Power and Energy Systems ; Volume 85 , 2017 , Pages 200-211 ; 01420615 (ISSN) Ameli, A ; Ahmadifar, A ; Shariatkhah, M. H ; Vakilian, M ; Haghifam, M. R ; Sharif University of Technology
    Elsevier Ltd  2017
    Abstract
    In distribution systems, feeder reconfiguration (FR) can lead to loss reduction, reliability improvement and some other economic savings. These advantages can be intensified by proper control and switching of Capacitor Banks (CBs). In this paper, using Ant Colony Optimization (ACO) technique, a novel method is proposed for simultaneous dynamic scheduling of FR and CB switching in the presence of DG units having uncertain and variant generations over time. This method is applicable to both smart and classic distribution systems. While for the latter, state estimation method should be used to estimate the loads at different buses by employing a limited number of measurements. The objective of... 

    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) Akbari, H ; 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 Nasiri Kalkhoran, Shahrokh (Author) ; 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.... 

    Kinetic Study of Partial Oxidation of Methane in Non-Catalytic Porous Media

    , M.Sc. Thesis Sharif University of Technology Rahimpour Kalkhoran, Mehrnaz (Author) ; 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... 

    Application of population balance equation in modeling of asphaltene particle size distribution and characterization of aggregation mechanisms under miscible gas Injection

    , Article Journal of Molecular Liquids ; Volume 232 , 2017 , Pages 207-213 ; 01677322 (ISSN) Moradi, S ; Hamed Mahvelati, E ; Ameli, F ; Dabir, B ; Rashtchian, D ; Sharif University of Technology
    Elsevier B.V  2017
    Abstract
    Particle size distribution (PSD) is an important factor that determines how asphaltene instability can damage porous media during natural depletion and enhanced oil recovery processes. In this work, aggregate size distribution under natural depletion and miscible nitrogen injection processes are determined via image analysis techniques and the results are modelled by population balance equation. Unimodal distribution curves in natural depletion show the dominance of particle-particle aggregation mechanism and the clustering is detected only around crude oil bubble point pressure. It is also observed that miscible nitrogen injection considerably increases the number and size of asphaltene... 

    A novel simultaneous reconfiguration and capacitor switching method to improve distribution networks operation

    , Article 2014 14th International Conference on Environment and Electrical Engineering, EEEIC 2014 - Conference Proceedings ; May , 2014 , pp. 295-300 ; ISBN: 9781479946617 Ameli, A ; Davari-Nejad, E ; Kamyab, F ; Vakilian, M ; Haghifam, M. R ; Sharif University of Technology
    2014
    Abstract
    Due to the important role that distribution systems play in quality of power delivered to the customers, there has always been a great deal of interest in investigating different methods of efficiency enhancement for these networks. Two of these methods are Feeder Reconfiguration (FR) and Capacitor Allocation (CA); both have been widely employed to reduce losses and improve several other operational characteristics in electrical power distribution systems. As in FR process the topology of the network changes, it is necessary to change some previous settings; for instance: the capacity of capacitor banks in service in each bus, after each reconfiguration process. This is due to the fact that... 

    Mathematical study of probe arrangement and nanoparticle injection effects on heat transfer during cryosurgery

    , Article Computers in Biology and Medicine ; Volume 66 , Nov , 2015 , Pages 113-119 ; 00104825 (ISSN) Mirkhalili, S. M ; Ramazani S. A. A ; Nazemidashtarjandi, S ; Sharif University of Technology
    Elsevier Ltd  2015
    Abstract
    Blood vessels, especially large vessels have a greater thermal effect on freezing tissue during cryosurgery. Vascular networks act as heat sources in tissue, and cause failure in cryosurgery and reappearance of cancer. The aim of this study is to numerically simulate the effect of probe location and multiprobe on heat transfer distribution. Furthermore, the effect of nanoparticles injection is studied. It is shown that the small probes location near large blood vessels could help to reduce the necessary time for tissue freezing. Nanoparticles injection shows that the thermal effect of blood vessel in tissue is improved. Using Au, Ag and diamond nanoparticles have the most growth of ice ball... 

    Mechanical, rheological and oxygen barrier properties of ethylene vinyl acetate/diamond nanocomposites for packaging applications

    , Article Diamond and Related Materials ; Volume 99 , 2019 ; 09259635 (ISSN) Amini, M ; Ramazani S. A., A ; Haddadi, S. A ; Kheradmand, A ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    In this work, the effects of the surface-modified nanodiamond particles (NDs) on the barrier, rheological, mechanical and thermal properties of ethylene vinyl acetate (EVA) composites for the packaging applications were investigated. Fourier transform infrared spectroscopy, as well as thermal gravimetric analysis were employed to study the grafting of vinyltriethoxy silane (VTS) on the surface of NDs. Afterwards, EVA samples containing 0, 0.1, 0.5, 1, 1.5 and 2 wt% of surface-modified NDs were prepared by a two-stage process including the solution and injection processes. In order to evaluate the physicochemical, rheological, mechanical and thermal properties of the EVA/NDs samples, field... 

    Effect of bonding parameters on microstructure development during TGTLP bonding of Al7075 alloy

    , Article Philosophical Magazine ; Vol. 94, issue. 11 , Mar , 2014 , pp. 1166-1176 ; ISSN: 14786435 Afghahi, S. S. S ; Ekrami, A ; Farahany, S ; Jahangiri, A ; Sharif University of Technology
    2014
    Abstract
    The effect of temperature, pressure and bonding time on microstructure of temperature gradient transient liquid phase (TGTLP) diffusion bonded Al7075 alloy using liquid gallium interlayer was investigated. The selected bonding method relies on using the minimum amount of liquid gallium on faying surfaces, using a very fast heating rate to reach the joining temperature and imposing a temperature gradient across the bond region. The microstructure of the diffusion bonded joints was evaluated by light optical microscopy, scanning electron microscopy and energy dispersive spectroscopy (EDS). Results show that by increasing the temperature, pressure and time of joining, a more uniform...