Loading...
Search for: naz-taher--f
0.115 seconds

    Design and optimization of reliable hardware accelerators: leveraging the advantages of high-level synthesis

    , Article 2018 IEEE 24th International Symposium on On-Line Testing and Robust System Design, IOLTS 2018, 2 July 2018 through 4 July 2018 ; 2018 , Pages 232-235 ; 9781538659922 (ISBN) Naz Taher, F ; Kishani, M ; Carrion Schafer, B ; Sharif University of Technology
    2018
    Abstract
    This work proposes an automatic method to generate opti- mized redundant hardware accelerator with maximum reliabil- ity given a single behavioral description for High-Level Syn- thesis (HLS). For this purpose, this work exploits one of the main advantages of C-based VLSI design over traditional RT- level design: The ability to generate micro-architectures with unique characteristics from the same behavioral description. This is typically done by setting different synthesis options to determine how to synthesize loops, arrays and functions and to specify the number and type of Functional Units (FUs) to be instantiated. The proposed method is composed of two main phases. The first phase... 

    Emergence of molecular chirality by vibrational Raman scattering

    , Article Physical Review A - Atomic, Molecular, and Optical Physics ; Volume 88, Issue 3 , 2013 ; 10502947 (ISSN) Taher Ghahramani, F ; Shafiee, A ; Sharif University of Technology
    2013
    Abstract
    In this study, we apply the monitoring master equation describing decoherence of internal states to an optically active molecule prepared in a coherent superposition of nondegenerate internal states interacting with thermal photons at low temperatures. We use vibrational Raman scattering theory up to the first chiral-sensitive contribution, i.e., the mixed electric-magnetic interaction, to obtain scattering amplitudes in terms of molecular polarizability tensors. The resulting density matrix is used to obtain elastic decoherence rates  

    Fundamental Study of Entanglement and its Application in Chirality Problem

    , Ph.D. Dissertation Sharif University of Technology Taher Ghahramani, Farhad (Author) ; Shafiee, Afshin (Supervisor)
    Abstract
    The origin of life is one of the fundamental problems of the science, which is not yet answered appositely. The building blocks of life’s molecules, including nucleic acids (DNA and RNA) and proteins, are composed of carbohydrates and amino acids. At the chemical level, these building blocks have definite chirality. This phenomenon is known as biological homochirality. Due to the fact that this phenomenon has taken place in the early stages of life, it is believed that the life’s origin is to a great extent connected to the origin of biological homochirality. Like every other system, at the microscopic level, life’s molecules are composed of atoms which are governed by the lows of quantum... 

    Comparing the Performance of Centrifuge, Membrane Filter and Filter Press for Clarification of Lipase Enzyme

    , M.Sc. Thesis Sharif University of Technology Taheraslani, Ahmad Reza (Author) ; Rousta Azad, Reza (Supervisor)
    Abstract
    Lipases (Triacyl Glycerol Acyl Hydrolase, EC.3.1.1.3) are multidimensional biocatalysts which have many applications in food industrials, dairy, fats and oils processing, detergents, synthesis of pure chemical and pharmaceutical materials, paper industrial and cosmetics. Generally, industrial enzymes are produced extracellularly, so their separation from a low-cost complex medium (usually used for production) is one of the cost stages in their production process. Filtration is the most economical method of separation in the production of enzymes, but due to the small size of colloidal particles and cell masses present in the fermentation environment, its use is subject to limitations. In... 

    Design and Development of a Space Solar Panel Electronic Simulator

    , M.Sc. Thesis Sharif University of Technology Mahmoudi, Hiwa (Author) ; Faez, Rahim (Supervisor) ; Taher Bane, Mohsen (Co-Advisor)
    Abstract
    The main power source of many space systems, are solar panels which are mainly affected from irradiance, temperature and particles radiation and an electronic solar panel simulator is a power-supply system that simulates the output of the solar panel. This system by processing of input data such as environment conditions, panel specifications and etc, simulate panel behavior and it can set the IV curve of the panel in different conditions. In this thesis, after introducing electronic solar panel simulators (chapter one), photovoltaic cells (chapter two) and space environment and its effects on space systems (chapter three), modeling solar panel based on the equivalent circuit of a solar... 

    An Application of Deep Reinforcement Learning for Ambulance Allocation to Emergency Departments under Overcrowding Situation

    , M.Sc. Thesis Sharif University of Technology Taher Gandomabadi, Mohammad Mahdi (Author) ; Akhavan Niaki, Taghi (Supervisor)
    Abstract
    In the last decade, emergency department (ED) overcrowding has become a national crisis for the US healthcare system. Increasing mortality rates, decreasing quality of care, financial losses due to walkouts, and ambulance diversion are some of the consequences of ED overcrowding. Given the increasing demand in terms of ambulance utilization which we can see an instance of it in the COVID-19 pandemic, being able to allocate service requests to EDs efficiently, becomes a key function of emergency medical services. in this investigation, an algorithm of deep reinforcement learning called deep Q-learning is used to address this problem and to assign ambulances to ED's appropriately. under... 

    An integrated lot-sizing policy for the inventory management of constrained multi-level supply chains: null-space method

    , Article International Journal of Systems Science: Operations and Logistics ; 2022 ; 23302674 (ISSN) Gharaei, A ; Amjadian, A ; Amjadian, A ; Shavandi, A ; Hashemi, A ; Taher, M ; Mohamadi, N ; Sharif University of Technology
    Taylor and Francis Ltd  2022
    Abstract
    The null-space method (NSM) for solving the nonlinear programming (NLP) is used to transform an indefinite system into a symmetric positive definite one of a smaller dimension. In this paper, an NSM optimises the constrained NLP model of the inventories in multi-level supply chains (SCs). The presented NSM can give a direct method with a predictable level of fill without pivoting, decreasing the number of taken iterations to find the optimum solution. We transform the nonlinear equations into an NLP model, which NSM can solved. We also investigate the suitability of using null-space-based factorisations to derive sparse direct methods. Accordingly, an integrated lot-sizing model of the... 

    Direct Synthesis of Dimethyl Ether from Carbon Dioxide

    , M.Sc. Thesis Sharif University of Technology Taheraslani, Mohammad Reza (Author) ; Kazemeini, Mohammad (Supervisor) ; Aghaziarati, Mahmoud ($item.subfieldsMap.e) ; Kazemian, Masoud ($item.subfieldsMap.e)
    Abstract
    In this research, direct synthesis of dimethyl ether (DME) from CO2 hydrogenation in three phase slurry reactor was investigated. Bifunctional catalysts composed of Cu- ZnO-Al2O3-ZrO2 as hydrogenation component and zeolite Na-Mordenite as dehydration component, with different Al2O3 and ZrO2 contents were synthesized by coprecipitating sedimentation and influences of Al2O3 and ZrO2 on CO2 conversion and DME selectivity were evaluated. Results show, both Al2O3 and ZrO2 enhanced conversion, but Al2O3 markedly increase selectivity of DME. However, when the total contents of Al2O3 and ZrO2 was increased up to 16 wt% , CO2 conversion and DME selectivity remarkably decreased. BET and XRD analyzes... 

    A thorough analysis of renewable hydrogen projects development in Uzbekistan using MCDM methods

    , Article International Journal of Hydrogen Energy ; Volume 46, Issue 61 , 2021 , Pages 31174-31190 ; 03603199 (ISSN) Mostafaeipour, A ; Hosseini Dehshiri, S. S ; Hosseini Dehshiri, S. J ; Almutairi, K ; Taher, R ; Issakhov, A ; Techato, K ; Sharif University of Technology
    Elsevier Ltd  2021
    Abstract
    The energy supply system of Uzbekistan is not well positioned to meet the rapidly rising domestic energy demand of this country. Uzbekistan's current energy supply system is outdated and has very low diversity, as most of its energy comes from natural gas. In addition to producing immense amounts of greenhouse gas and environmental pollution, this situation is untenable considering the eventual depletion of fossil fuel reserves of this country. Uzbekistan's renewable energy sector is highly undeveloped, a situation that can be attributed to the lack of coherent policies for the advancement of renewable power and the low price of natural gas. However, this country has significant untapped... 

    Effect of heating profile on desorption curve in temperature programmed desorption analysis: Case study of acid sites distribution of SAPO-34

    , Article Journal of Porous Materials ; Volume 16, Issue 5 , 2009 , Pages 599-603 ; 13802224 (ISSN) Izadbakhsh, A ; Farhadi, F ; Khorasheh, F ; Yan, Z. F ; Sharif University of Technology
    2009
    Abstract
    Comparison of the traditional linear heating method of TPD with an original stepwise heating scheme was reported for the first time. Stepwise heating TPD was carried out by keeping the temperature constant as soon as ammonia desorption signal rises until the signal returns to the baseline. More ammonia desorption peaks on a SAPO-34 catalyst were identified using TPD with stepwise heating. The effect of temperature ramp on desorption peak broadening in TPD curve was also addressed. The more distinct ammonia desorption peaks in stepwise TPD indicates that ammonia adsorbs in about five or six different ways on SAPO-34, and attribution of different adsorptions may be explained considering some... 

    Theoretical and experimental study of cascade solar stills

    , Article Solar Energy ; Volume 90 , April , 2013 , Pages 205-211 ; 0038092X (ISSN) Ziabari, F. B ; Sharak, A. Z ; Moghadam, H ; Tabrizi, F. F ; Sharif University of Technology
    2013
    Abstract
    Most part of Iran is dominated by arid and semi-arid areas due to low annual rainfall. The need for production of fresh water from brackish water is considerably high, especially in dry regions. In this study 1 month daily-based experimental data from a solar still site has been reported. The technical and operational problems of this site which finally contributed to the total cease of the site are described. Then a detailed analysis is investigated on progress of a prototype which constructed in order to solve the site's problems. The results of 1 month of experimental data of the final design showed that the last prototype could be used to solve the current problems of the site. The... 

    Application of a continuous kinetic model for the hydrocracking of vacuum gas oil

    , Article Petroleum Science and Technology ; Vol. 32, Issue. 18 , 2014 , Pages 2245-2252 ; ISSN: 10916466 Arefi, A ; Khorasheh, F ; Farhadi, F ; Sharif University of Technology
    2014
    Abstract
    Hydrocracking is one of the most versatile petroleum refining processes for production of valuable products including gasoline, gas oil, and jet fuel. In this paper, a five-parameter continuous lumping model was used for kinetic modeling of hydrocracking of vacuum gas oil (VGO). The model parameters were estimated from industrial data obtained from a fixed bed reactor operating at an average temperature of 400°C and residence time of 0.3 h. Product distributions were obtained in terms of the weight fraction of various boiling point cuts. The model parameters were estimated using the Nelder-Mead optimization procedure and were correlated with temperature. Comparison of experimental and... 

    An improved methodology for design of custom-made hip prostheses to be fabricated using additive manufacturing technologies

    , Article Rapid Prototyping Journal ; Volume 18, Issue 5 , 2012 , Pages 389-400 ; 13552546 (ISSN) Rahmati, S ; Abbaszadeh, F ; Farahmand, F ; Sharif University of Technology
    Emerald  2012
    Abstract
    Purpose - The purpose of this paper is to present an improved methodology for design of custom-made hip prostheses, through integration of advanced image processing, computer aided design (CAD) and additive manufacturing (AM) technologies. Design/methodology/approach - The proposed methodology for design of custom-made hip prostheses is based on an independent design criterion for each of the intra-medullary and extra-medullary portions of the prosthesis. The intra-medullar part of the prosthesis is designed using a more accurate and detailed description of the 3D geometry of the femoral intra-medullary cavity, including the septum calcar ridge, so that an improved fill and fit performance... 

    Evaluation and enhancing of operational performance and training objective in accordance with Line Operations Safety Audit (LOSA)

    , Article International Air Safety Seminar Proceedings, 1 November 2011 through 3 November 2011 ; November , 2011 , Pages 78-99 ; 02705176 (ISSN) ; 9781618393975 (ISBN) Khoshkhoo, R ; Goodarzi, F ; Sharafbafi, F ; Sharif University of Technology
    2011

    Real-time impulse noise suppression from images using an efficient weighted-average filtering

    , Article IEEE Signal Processing Letters ; Volume 22, Issue 8 , 2015 , Pages 1050-1054 ; 10709908 (ISSN) Hosseini, H ; Hessar, F ; Marvasti, F ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2015
    Abstract
    In this letter, we propose a method for real-time high density impulse noise suppression from images. In our method, we first apply an impulse detector to identify the corrupted pixels and then employ an innovative weighted-average filter to restore them. The filter takes the nearest neighboring interpolated image as the initial image and computes the weights according to the relative positions of the corrupted and uncorrupted pixels. Experimental results show that the proposed method outperforms the best existing methods in both PSNR measure and visual quality and is quite suitable for real-time applications  

    Kinetic modeling of pyrolysis of scrap tires

    , Article Journal of Analytical and Applied Pyrolysis ; Volume 84, Issue 2 , 2009 , Pages 157-164 ; 01652370 (ISSN) Mazloom, G ; Farhadi, F ; Khorasheh, F ; Sharif University of Technology
    2009
    Abstract
    The disposal of used tires is a major environmental problem. With increasing interest on recovery of wastes, pyrolysis is considered as an alternative process for recovering some of the value in scrap tires. An accurate kinetic model is required to predict product yields during thermal or catalytic pyrolysis of scrap tires. Pyrolysis products contain a variety of hydrocarbons over a wide boiling range. A common approach for kinetic modeling of such complex systems is lumping where each lump is defined by a boiling point range. Available experimental data for thermal and catalytic pyrolysis of scrap tires from the literature were used to evaluate two types of lumping models; discrete and... 

    Determine oil content in petroleum waxes

    , Article Hydrocarbon Processing ; Volume 85, Issue 6 , 2006 , Pages 95-97 ; 00188190 (ISSN) Mafi, M ; Yazdani, F ; Farhadi, F ; Sharif University of Technology
    2006

    Analytical modeling of variable-reluctance tubular resolver based on magnetic equivalent circuit and conformal mapping

    , Article IEEE Transactions on Instrumentation and Measurement ; Volume 70 , 2021 ; 00189456 (ISSN) Keyvannia, A ; Zare, F ; Tootoonchian, F ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2021
    Abstract
    Compared with flat linear structures, tubular linear machines do not face edge effects, making their performance better than their flat counterparts. In this article, a novel linear variable-reluctance resolver with tubular configuration is proposed. To optimize the design of an electromagnetic structure, modeling methods are used. Thus, in this article, an analytical model for the proposed resolver is presented. This model is based on the magnetic equivalent circuit (MEC) method and is considerably less time-consuming than finite element analysis (FEA), yet provides accurate results. A conformal mapping is employed to compute the permeance of the air-gap. The proposed model is then utilized... 

    Information and the Brukner-Zeilinger interpretation of quantum mechanics: A critical investigation

    , Article Foundations of Physics Letters ; Volume 19, Issue 1 , 2006 , Pages 1-20 ; 08949875 (ISSN) Shafiee, A ; Safinejad, F ; Naqsh, F ; Sharif University of Technology
    2006
    Abstract
    In Brukner and Zeilinger's interpretation of quantum mechanics, information is introduced as the most fundamental notion and the finiteness of information is considered as an essential feature of quantum systems. They also define a new measure of information which is inherently different from the Shannon information and try to show that the latter is not useful in defining the information content in a quantum object. Here, we show that there are serious problems in their approach which make their efforts unsatisfactory. The finiteness of information does not explain how objective results appear in experiments and what an instantaneous change in the so-called information vector (or catalog of... 

    Key parameters in hydrothermal synthesis and characterization of low silicon content SAPO-34 molecular sieve

    , Article Microporous and Mesoporous Materials ; Volume 126, Issue 1-2 , 2009 , Pages 1-7 ; 13871811 (ISSN) Izadbakhsh, A ; Farhadi, F ; Khorasheh, F ; Sahebdelfar, S ; Asadi, M ; Yan, Z. F ; Sharif University of Technology
    2009
    Abstract
    Low silicon content SAPO-34 was successfully synthesized using the conventional hydrothermal crystallization in the static condition. Effects of different synthesis conditions including crystallization temperature and the silicon source were investigated through X-ray diffraction patterns. It was concluded that the silicon source had a significant effect on silicon incorporation into the alumino-phosphate building blocks in the course of crystallization. Using precipitated silica instead of silica sol resulted in the formation of impurities of alumino-phosphates phases whose crystalline structures collapse at the high temperature of calcination. For the low silicon SAPO-34 synthesis, the...