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    Modelling and Prediction of Water Quality of Dam Reservoir Using CE-QUAL-W2 Model and Machine Learning Methods (Case Study: Shahr Bijar Dam)

    , M.Sc. Thesis Sharif University of Technology Ebrahimi, Abolfazl (Author) ; Shamsai, Abolfazl (Supervisor) ; Ghaemian, Mohsen (Supervisor)
    Dams are constructed for various purposes, including flood control, drinking water supply, agriculture irrigation, electricity generation, etc. The dam converts the river's natural and dynamic flow into a stagnant artificial lake where humans control the outflow of water, reducing the velocity of water movement and increasing residence time, followed by the entry and accumulation of nutrients in the reservoir, resulting in phenomena such as thermal stratification and eutrophication. Due to the changing climatic conditions of Iran and sudden droughts and wet periods, the need to monitor the water level of dam reservoirs and their water quality to keep them in the best operational condition... 

    Pre-trained Model utilization Using Cross-lingual Methods

    , M.Sc. Thesis Sharif University of Technology Hosseini, Mohammad (Author) ; Sameti, Hossein (Supervisor) ; Motahari, Abolfazl (Supervisor)
    Following dramatic changes after using deep learning method as a solution for Natural Language Processing tasks, Transformer architecture get popular. Based on that, then BERT Language model presented and get state-of-the-art as a solution for a lot of language processing tasks. It was a turning point in Natural Language Processing field. Also, in cross-lingual methods research line motivated by developing a common space for representation of language units, e.g. words, sentences, in more that one language, get some remarkable improvements. However, for languages distant from English such as Persian or Arabic the methods' performance was not clear. In this work, we performed some innovative... 

    Investigating Sediment Transport in Deep Reservoirs Using the 3D Numerical Model MIKE3

    , M.Sc. Thesis Sharif University of Technology Eydpour, Danial (Author) ; Shamsai, Abolfazl (Supervisor) ; Ghaemial, Mohsen (Supervisor)
    Nowadays, in the world and our country, Iran, sediment transport and the phenomenon of sedimentation are of great importance. The entry of water flow with suspended sediments into the dam reservoir by floods with different return periods during the initial period of dam construction causes a considerable part of the helpful volume of the reservoir to be filled with sediments. As a result, the discharge of these sediments and the methods that exist in this field should be studied so that a large volume of reservoir water is not wasted during the discharge of these sediments. In this research, the opening time and extent of the bottom outlets of Qeshlaq Dam when the flood enters the reservoir... 

    Control over Fading Channels

    , M.Sc. Thesis Sharif University of Technology Sarmashghi, Shahabeddin (Author) ; Farhadi, Alireza (Supervisor) ; Motahari, Abolfazl (Supervisor)
    As latency reduction is a key objective of upcoming mobile standards such as 5G, control applications over such channels have become of high interest in recent years. In this thesis, we will consider the problem of control over fading channels modeled by finite-state Markov chains. We will combine communication and control theory aspects of the problem and study stability of linear discrete-time plants which communicate with the controller over such fading channels. Two different scenarios are assumed for channel state information availability at encoder side, and the sufficient condition of almost sure asymptotic stabilizability is derived for each scenario. We will then examine the... 

    Genome-Wide Association Study via Machine Learning Techniques

    , M.Sc. Thesis Sharif University of Technology Najafi, Amir (Author) ; Fatemizadeh, Emad (Supervisor) ; Motahari, Abolfazl ($item.subfieldsMap.e)
    Development of DNA sequencing technologies in the recent years magnifies the need for computational tools in genomic data processing, and thus has attracted inten- sive research interest to this area. Among them, Genome-Wide Association Study (GWAS) refers to discovering of causal relationships among genetic sequences of living organisms and the macroscopic phenotypes present in their physiological structure. Chosen phenotypes for genomic association studies are mostly vulnerability or im- munity to common genetic diseases. Conventional methods in GWAS consists of statistical hypothesis testing algorithms in case/control approaches; Most of which are based upon single-locus analysis and... 

    Source Tracing of the Dust Storms to the Country Using the Nuclear Techniques

    , M.Sc. Thesis Sharif University of Technology Bagri, Mohammad (Author) ; Sohrabpour, Mostafa (Supervisor) ; Hosseini, Abolfazl (Co-Advisor)
    Dust phenomenon is a combination of tiny particle with urban pollution that it is harmful for respiratory disease. But this phenomenon has been prevalent in our country recently. We utilized NASA satellite pictures to observe dust storms in the present project. We have collected images of possible sources of dust on the days when we are faced with the dust storm phenomenon. Then by processing of NASA satellite pictures (recognition of distribution of optical and particle density in the dust particle arising and comparing results through analysis of these images to estimate the main characteristics of the sampling locations). we have find the desired location for taking samples of soil... 

    Private shotgun and sequencing

    , Article 2019 IEEE International Symposium on Information Theory, ISIT 2019, 7 July 2019 through 12 July 2019 ; Volume 2019-July , 2019 , Pages 171-175 ; 21578095 (ISSN); 9781538692912 (ISBN) Gholami, A ; Maddah Ali, M. A ; Abolfazl Motahari, S ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2019
    Current techniques in sequencing a genome allow a service provider (e.g. a sequencing company) to have full access to the genome information, and thus the privacy of individuals regarding their lifetime secret is violated. In this paper, we introduce the problem of private DNA sequencing, where the goal is to keep the DNA sequence private to the sequencer. We propose an architecture, where the task of reading fragments of DNA and the task of DNA assembly are separated, the former is done at the sequencer(s), and the later is completed at a local trusted data collector. To satisfy the privacy constraint at the sequencer and reconstruction condition at the data collector, we create an... 

    Inferring the Demographic History of Iranian Populations from Whole Exome Sequencing Data

    , M.Sc. Thesis Sharif University of Technology Heidari, Jalal (Author) ; Motahari, Abolfazl (Supervisor) ; Khalaj, Babak (Supervisor)
    One of the cornerstones of population genetics is finding ancestral relations between people of a population. Mutations and recombinations are two major signals that can be exploited to infer the population ancestral relationships. Next Generation Sequencing (NGS) has paved the way for achieving this endeavor by providing massive data including single nucleotide polymorphisms, insertions, and deletions as well as structural variations between individuals. In this thesis, the goal is to infer the ancestral structure of a given gene from thousands of NGS datasets. We also attempt to decode times of important events including mutations and recombinations. To this end, we first split a gene into... 

    Investigation of Ocular Tumor Dose Enhancement in Proton Therapy in the Presence of Nanoparticles of Different Materials

    , M.Sc. Thesis Sharif University of Technology Alamgir, Jafar (Author) ; Hosseini, Abolfazl (Supervisor) ; Salimi, Ehsan (Supervisor)
    In recent years, the effect of the presence of nanoparticles in the tumor in order to increase the benefit of the treatment in radiation therapy has been the focus of many researchers. Although for photon irradiation, a significant dose increase due to the presence of nanoparticles has been observed, in the case of proton irradiation, due to the different nature of the beam and the lower cross-section of protons with metals compared to photons, scattered and in some cases contradictory findings have been published in the articles, and more studies are needed in this field. Due to laboratory limitations, Monte Carlo simulation is an appropriate tool for simulating difficult real-world... 

    Simulation and Optimization of Neutron Activation Analysis Using the K0- IAEA Software and Comparison with the Experimental Results

    , M.Sc. Thesis Sharif University of Technology Sattari Heris, Aghil (Author) ; Vossoughi, Naser (Supervisor) ; Hosseini, Abolfazl (Supervisor)
    Neutron activation is a nuclear method for determination of elements in each sample. In this method, the samples are exposed to neutron irradiation by neutrons which are usually produced by research reactor, and then the core becomes unstable due to capturing the neutron and emits gamma rays. The emitted gamma rays can be detected by a detector like a HPGe semiconductor which has a high resolution. All nucleuses have a probability of neutron absorption, expressed by the absorption cross section area. The radioactive nuclei value depends on the nuclear half-life and the number of unstable nuclei. The only Windows environment commercial software for neutron activation analysis was K0 for... 

    Improvement Compton Imaging System Based on Semiconductor Detectors

    , M.Sc. Thesis Sharif University of Technology Niknami, Mostafa (Author) ; Hosseini, Abolfazl (Supervisor) ; Ebrahimi Loushab, Mahdi (Co-Supervisor)
    Compton imaging is an imaging technique in which Compton scattering is used to produce images from a gamma-ray source. Compton imaging systems are also known as Compton cameras. The basic design of Compton imaging systems consists of two-position detectors that are sensitive to the position and energy scattered from gamma rays. The gamma rays collide with the Compton scatterer detector and the scattered photons are absorbed in the absorber detector. Compton imaging performs well the ground radiation during the scattering processes through the separation of energy. The quality of images produced by Compton imaging depends on a variety of factors including detector energy resolution,... 

    Movement of Entrapped Air-Pockets in the Bottom Outlet of Dams and Solutions to Related Problems

    , M.Sc. Thesis Sharif University of Technology Nayeb Pashaie, Kiarash (Author) ; Shamsaei, Abolfazl (Supervisor) ; Ghaemian, Mohsen (Supervisor)
    The purpose of this study is to investigate the entrapment and movement of air pockets in the bottom outlet of dams and numerical simulation of the process of entrapment and entrainment of air pockets. One of the most common problems with bottom outlets is the air-water mixture flow. The main purpose of this study is to investigate the causes of air pockets in pressurized tunnels before service and emergency gates in the bottom outlets and to provide effective solutions to prevent the occurrence of unwanted air entrapment and many problems resulting from it. To do this, using FLOW-3D flow simulator, the way of entraping air pockets in the Bottom outlet of Darian Dam has been investigated and... 

    Simulation of Bushehr Nuclear Power Plant Hot Channel Using ANSYS CFX 18.0 Software

    , M.Sc. Thesis Sharif University of Technology Asadi, Ali Asghar (Author) ; Ghafari, Mohsen (Supervisor) ; Hosseini, Abolfazl (Co-Supervisor)
    In nuclear power plants, the fission reaction takes place inside the fuel rods, and the heat generated inside the fuel rods is transferred through the clad wall to the cooling fluid, which is single-phase, subcooled and in the turbulence zone. In the hot channel of the reactor core, where the axial and radial heat flux reaches its maximum state, the fluid leaves the single-phase state and some steam is formed in the area close to the clad wall.Therefore, in some cases, in the hot channel, the steam near the clad wall may reach a point that reduces the heat transfer coefficient, rapidly increases the wall temperature and thus destroys or melts the sheath surface. If this happens, it means... 

    Numerical Simulation of Hydrodynamics of Flow over Gabion Stepped Weir

    , M.Sc. Thesis Sharif University of Technology Mousavi Khomeyrani, Zahra (Author) ; Shamsai, Abolfazl (Supervisor) ; Ghaemian, Mohsen (Co-Supervisor)
    The use of stepped weirs dates back at least 3500 years. In this research, the hydrodynamics of gabion stepped weirs have been investigated as a three-dimensional simulation of two-phase flow air-water using Flow3D software and the method of computational fluid dynamics (CFD) analysis. In order to solve the Reynolds-Averaged Navier-Stokes (RANS) equations, the RNG turbulence model (k-ε) was used and the free surface elevation of fluid was determined by the volume of fluid (VOF) method. The experimental results of Wutrish and Chanson (2014) over gabion stepped weirs are used to validate the numerical model simulations. Gabion stepped weirs with steps of 3, 7.5, and 10 cm in height, as well as... 

    Neutron Noise Reconstruction Based on Neuro-Fuzzy Computing for VVER-1000 Reactor Core

    , M.Sc. Thesis Sharif University of Technology Pouyani Rad, Armin (Author) ; Vosoughi, Naser (Supervisor) ; Hosseini, Abolfazl (Co-Supervisor)
    In this study, the reconstruction of the neutron noise source in the core of the VVER-1000 reactor was carried out using fuzzy neural network and parallel processing of parallel process circuit design. The noise of power reactors is derived from neutron fluctuations. Which are affected by fluctuations in reactor characteristics. These oscillations can be caused by the displacement of the elements forming the core or due to changes in temperature or density and so on. It is clear that any change in the elements of a reactor will make itself a change in the corresponding to cross-section of material. These changes called as pertubation. In this project, by using neuro-fuzzy network... 

    Learning of Statistical Mixture Models in High Dimensions

    , Ph.D. Dissertation Sharif University of Technology Najafi, Amir (Author) ; Motahari, Abolfazl (Supervisor) ; Rabiee, Hamid Reza (Supervisor)

    Using statistical tools in machine learning and artificial intelligence to infer knowledge from high-dimensional data, namely data science, has attracted a siginificant research interest over the past two decades. The number of real databases around the world continues to grow with an increasing pace, which are used to store huge amounts of high-dimensional data points of various types. However, applying machine learning tools to high-dimensional data has also raised potential concerns, specially with respect to the fundamental capability of such tools to be useful in practical situations. In fact, the large dimension of a data could eventually damage the outcome of any statistical... 

    Proposing a Hybrid Method for Reducing the Artifact of the Computed Tomography (CT) Images

    , M.Sc. Thesis Sharif University of Technology Ghorbanzadeh, Mohammad (Author) ; Hosseini, Abolfazl (Supervisor) ; Vosoughi Vahdat, Bijan (Supervisor)
    Over the past few decades, computed tomography (CT) has been introduced as one of the leading cross-sectional imaging techniques in a wide range of clinical applications in diagnostic radiology, oncology, and multimodal molecular imaging. Despite the recognized value of this imaging technique, the quality and accuracy of CT images can be compromised by a number of physical destructive factors. The presence of metal objects such as dental fillings, hip or knee prostheses, heart pacemakers, war fragments and spinal cages can cause and intensify image artifacts. These types of artifacts appear as black and white lines in the image, obscuring the structures and textures around the metal implant... 

    Development of a Balance Assessment Method in Dynamic Tasks (LOS) Using a Sway Control Model in Parkinson's Disease

    , M.Sc. Thesis Sharif University of Technology Jasimi Zindashti, Niromand (Author) ; Behzadipour, Saeed (Supervisor) ; Mohebbi, Abolfazl (Co-Supervisor)
    Parkinson's disease impairs the patients' balance with the degeneration of the neurons related to their postural control. There are many rehabilitation methods to preclude the disease or weaken its effects. To assess the influence of these methods and their outcome, there are two main evaluation methods, including clinical (qualitative and dependent on the presence of a therapist) and quantitative, such as posturography. Using control models is one of the quantitative methods researchers have been used for more than three decades. Considering this and what have been done in the literature, the purpose of this research is to develop a balance assessment method in dynamic tasks, such as the... 

    Experimental Investigation of Mobility and Reactivity of Iron Nanoparticles in Porous Media and Application for in-Situ Groundwater Remediation

    , Ph.D. Dissertation Sharif University of Technology Fadaei Tehrani, Mohammad Reza (Author) ; Shamsaei, Abolfazl (Supervisor) ; Vosoughi, Manoochehr (Supervisor)
    In the present study, synthesis, preparation, and application of bimetallic iron/nickel nano-particles were experimentally investigated with the aim of groundwater remediation. Firstly, iron/nickel nano-particles were synthesized according to chemical reduction and stabilization with starch biopolymer, and then characterized. Results confirmed the formation of bimetallic iron/nickel nano-particles with mean size of 75 nm that starch placed around of them. The more stability characteristic and also enough mobility ensure their diffusion through porous media. Secondly, reactivity of synthesized nano-particles for removal of various contaminants including nitrate, chromium, and lead were... 

    Learning of Alternative Splicing from RNA-seq Data

    , M.Sc. Thesis Sharif University of Technology Rashidi Mehrabadi, Farid (Author) ; Rabiee, Hamid Reza (Supervisor) ; Motahari, Abolfazl (Co-Advisor)
    We construct and analyse a computational model that predicts the outcome of alternative splicing by recognizing features in RNA sequences. The computational model can be viewed as a “splicing simulator” for a range of healthy human tissues. It takes as input a pre-mRNA sequence surrounding a possibly alternatively spliced exon and estimates the inclusion level of that exon in mature RNA, after splicing occurs. The model is trained using a supervised machine learning framework where the training examples are the alternatively spliced exons, the feature vectors are derived RNA sequences near these exons, and the targets are their corresponding splicing outcomes in healthy individuals. The...