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    Facilitating Data Exchange Between Streaming Processors in GPUs

    , Ph.D. Dissertation Sharif University of Technology Nematollahizadeh Mahani, Negin Sadat (Author) ; Sadrbazi Azad, Hamid (Supervisor)
    Abstract
    GPUs are used today to accelerate a wide range of general-purpose applications (e.g., regular stencil applications and irregular graph processing applications). Due to the significant growth of the Thread Level Parallelism (TLP) in GPGPU applications, the need for data sharing between different threads has become more apparent. There are a variety of solutions for reusing data in the GPU (e.g., on-chip caches and shuffle instructions), each with its own drawbacks and reduced comprehensiveness (e.g., limiting shared memory to a thread block and shuffle instructions to a warp). Among the standard general-purpose applications, L1 data cache is a major GPU solution for reusing data among... 

    Refining of Nanostructure of Polypropylene/Nanoclay Composite Via Optimization of Compatibilizer and Masterbatch

    , M.Sc. Thesis Sharif University of Technology Jalili, Negin Sadat (Author) ; Bagheri, Reza (Supervisor)
    Abstract
    Polypropylene (PP) is a fast growing polymer, particularly in automotive industry, where PP compounds have replaced many different parts made of conventional materials. In the first step, PP-g-MA, as compatibilizer, was synthesized. Two kinds of polypropylenes including a homo- and a block co-polymer were incorporated for this goal. Characterizations via titration and FTIR tests revealed higher degree of grafting reaction when homo-polymer was used for synthesizing PP-g-MA. In the next step, nanocomposites containing 3 wt% nanoclay with three different PP-g-MA/nanoclay ratios of 1:1, 2:1 and 3:1were made using a co-rotating twin screw extruder. Tensile, impact and XRD tests were performed to... 

    Oxidative coupling of methane on BaTiO3 perovskites partially substituted with germanium

    , Article 2008 AIChE Spring National Meeting, Conference, New Orleans, LA, 6 April 2008 through 10 April 2008 ; 2008 ; 9780816910236 (ISBN) Mohammadi Boghaee, D ; Hamidzadeh, M ; Negin, S ; Sharif University of Technology
    2008
    Abstract
    The perovskite oxide BaTiO3, doped with Ge oxides oxidized methane to C2 coupled hydrocarbons. The ultraviolet-visible spectra of pure barium titanate and Ge doped BaTi(1-x) GexO3 (x=0.05 ,0.1) were compared. The pure barium titanate exhibited an ultraviolet absorption effect. The addition of GeO2 resulted in an increase in absorption of wavelength. Therefore, small amount of Ge decreased band gap energy. Oxygen is inserted by nucleophilic attack which may be considered as an acid-base process. For promoted BaTiO3 catalysts with stable cation valance, electron donation ability of lattice oxygen is parallels to its ability of adsorb and active oxygen, and decrease the chance of deep oxidation... 

    Oxidative coupling of methane on BaTiO3 perovskites partially substituted with germanium

    , Article 2008 AIChE Spring National Meeting, Conference, New Orleans, LA, 6 April 2008 through 10 April 2008 ; 2008 ; 9780816910236 (ISBN); 9780816910236 (ISBN) Boghaee, D. M ; Hamidzadeh, M ; Negin, S ; Sharif University of Technology
    2008
    Abstract
    The perovskite oxide BaTiO3, doped with Ge oxides oxidized methane to C2 coupled hydrocarbons. The pure barium titanate exhibited an ultraviolet absorption effect. The addition of GeO2 resulted in an increase in absorption of wavelength. Small amount of Ge decreased band gap energy. For promoted BaTiO3 catalysts with stable cation valance, electron donation ability of lattice oxygen was parallel to its ability of adsorb and active oxygen, and decreased the chance of deep oxidation of methyl radicals and C2 hydrocarbons and thus will result in an increase of C2 yield. This is an abstract of a paper presented at the 42nd Loss Prevention Symposium (New Orleans, LA 4/6-10/2008)  

    Oxidative coupling of methane on BaTiO3 perovskites partially substituted with germanium

    , Article Catalysis and Reaction Engineering Division Conference, Presentations at the 2008 AIChE Spring National Meeting, 6 April 2008 through 10 April 2008 ; 2008 , Pages 89-94 ; 9781605602233 (ISBN) Boghaee, D. M ; Hamidzadeh, M ; Negin, S ; Sharif University of Technology
    AIChE  2008
    Abstract
    The perovskite oxide BaTiO3, doped with Ge oxides oxidized methane to C2 coupled hydrocarbons. The ultraviolet-visible spectra of pure barium titanate and Ge doped BaTi(1-x)GexO3(x=0.05,0.1) were compared. The pure barium titanate exhibited an ultraviolet absorption effect. The addition of GeO2 resulted in an increase in absorption of wavelength. Therefore, small amount of Ge decreased band gap energy. Oxygen is inserted by nucleophilic attack which may be considered as an acid-base process. For promoted BaTiO3catalysts with stable cation valance, electron donation ability of lattice oxygen is parallels to its ability of adsorb and active oxygen, and decrease the chance of deep oxidation of... 

    Cluster-based adaptive SVM: a latent subdomains discovery method for domain adaptation problems

    , Article Computer Vision and Image Understanding ; Volume 162 , 2017 , Pages 116-134 ; 10773142 (ISSN) Sadat Mozafari, A ; Jamzad, M ; Sharif University of Technology
    2017
    Abstract
    Machine learning algorithms often suffer from good generalization in testing domains especially when the training (source) and test (target) domains do not have similar distributions. To address this problem, several domain adaptation techniques have been proposed to improve the performance of the learning algorithms when they face accuracy degradation caused by the domain shift problem. In this paper, we focus on the non-homogeneous distributed target domains and propose a new latent subdomain discovery model to divide the target domain into subdomains while adapting them. It is expected that applying adaptation on subdomains increase the rate of detection in comparing with the situation... 

    Experimental Investigation of Formation Damage Caused by Wellbore Fluids Using Glass Micromodel

    , M.Sc. Thesis Sharif University of Technology Mohammadi, Mostafa (Author) ; Mahani, Hassan (Supervisor)
    Abstract
    During all operations in oil and gas reservoirs, it is possible to cause formation damage. These damages can greatly reduce the rate of production. One of the major damages that can seriously affect the performance of a reservoir is the damage caused by drilling fluid. The main purpose of this thesis is to study the main mechanisms of formation damage caused by water-based drilling fluid using a glass micromodel for the first time. An accurate understanding of the mechanisms of formation damage can provide a good understanding of the selection of the type and concentration of materials used, as well as appropriate methods to control and eliminate damages. for controlling the drilling fluid... 

    Investigation of Formation Damage and its Remediation Caused by Wellbore Fluids by Using Micromodel

    , M.Sc. Thesis Sharif University of Technology Khanzadeh, Ahmad (Author) ; Mahani, Hassan (Supervisor)
    Abstract
    Various methods have been developed to improve the production capacity of hydrocarbon wells, one of the most successful method is hydraulic fracture. This method, despite improving well production and increasing production levels in a reservoir, causes secondary damages such as water blockage, which is a result of the leakage of fracturing fluid into the fracture matrix and the deformation of the reservoir. This damage can reduce the production rate of a well. Studies prior to this study have mainly examined the damages caused by the leakage of fracturing fluids on a core scale. In most of these studies, damages has been studied only by measuring the pressure and changes in the permeability... 

    Treatment of diatomaceous earth to obtain its catalyst support

    , Article Scientia Iranica ; Volume 10, Issue 3 , 2003 , Pages 350-356 ; 10263098 (ISSN) Mahani, H ; Kazemeini, M ; Sharif University of Technology
    Sharif University of Technology  2003
    Abstract
    Treatment of diatomaceous earth with sulfuric acid reduces mineral and organic impurities, such as Fe2O3, Al2O3 and alkali metal oxides (CaO, MgO and Na2O). In addition, wettability and porosity of the acid-treated diatomite are greatly enhanced. Acid-treated diatomite is suitable to be used as a siliceous support for catalysts, due to high silica content (> 90%), amorphous structure with low cristobalite and quartz phases, appropriate Brunauer-Emmett-Teller surface area, high absorptive capacity, good mechanical strength after calcinations and low cost of production. In the first part of this study, the influence of temperature, sulfuric acid concentration, acid-diatomite mass ratio and... 

    Investigation of Formation Damage with Oil-Based Mud (Invert Emulsion) Using Microfluidic Method

    , M.Sc. Thesis Sharif University of Technology Madanchi, Parham (Author) ; Mahani, Hassan (Supervisor)
    Abstract
    Formation damage is one of the most important challneges in hydrocarbon production; drilling mud invasion is one of its common types. This damage is caused by the penetration of the drilling fluid into the porous media, which its filtrate and solid pareticles block the pores and cause permeability reduction. The main purpose of this thesis is to investigate the pore-scale mechanisms of the formation damage induced by invert-emulsion drilling fluid and to investigate the effect of adding nanoparticles to the drilling fluid on the severity of the damage using microfluidic technique. According to the latest published articles, there has not been any research conducted at the pore-scale with... 

    Core-scale Mechanistic Simulation of Engineered Salinity Waterflooding Using Bond-Product-Sum Method

    , M.Sc. Thesis Sharif University of Technology Almasian, Pourya (Author) ; Mahani, Hassan (Supervisor)
    Abstract
    Considering the world's diminishing oil reserves, as well as the growing demand for oil and energy consumption, Enhanced Oil Recovery (EOR) techniques are becoming increasingly important in the attempt to improve oil production. Engineering salinity waterflooding has gained widespread attention and popularity in the last two decades due to its environmental friendliness, lack of expensive additives, low operating costs, and ease of use as an oil extraction process. The goal of this study is to use an innovative method to develop a mechanistic approach model that simulates and forecasts the mechanism and performance of the engineered water flooding process. Wettability alteration, the most... 

    The Effect of Travel Time Reliability on Morning Peak Travellers route choice in Large Metropolitan Area

    , M.Sc. Thesis Sharif University of Technology Sadat Mirjafari, Parisa (Author) ; Poorzahedy, Hossein (Supervisor)
    Abstract
    Data collected from street networks show that travel time in urban street networks is a stochastic variable, whose range of variation increases with the congestion level. Work and school trips comprise the major part of morning peak volumes, whose common characteristic is that they need to be made on time. For this reason, these travelers are pessimistic in their route choice, and try to choose routes which are more reliable. Travel time standard deviation is one of the common measures for estimating travel time reliability that is related to properties of day-to-day travel time distribution on a particular route. Based on the empirical data collected from Tehran street network, this paper... 

    Indoor Noise Pollution Modeling: A Case Study on Resalat Tunnel

    , M.Sc. Thesis Sharif University of Technology Sadat Mortazavi, Mandana (Author) ; Vaziri, Manouchehr (Supervisor)
    Abstract
    Noise or noise pollution, is defined as an unwanted sound, produced mostly by motor vehicles in urban areas. If the noise exceeds its limit, adverse effects on users and citizens are expected. Thus the assessment of the noise level and its comparison with allowable values is mandatory. Traffic induced noise depends upon different factors such as traffic, weather, and, sound barriers. Noise pollution study has a long history all over the world. Many studies, mostly representing the outdoor noise pollution models, have been done in recent years. This paper presents an assessment of traffic-induced noise in a heavily traveled tunnel, locally referred to as Resalat tunnel, which is located in... 

    Using Information Beyond Text to Generate Language Embedding Vectors

    , M.Sc. Thesis Sharif University of Technology Zeinab Sadat Taghavi (Author) ; Sameti, Hossein (Supervisor)
    Abstract
    In this thesis, we introduce a novel Artificial Intelligence (AI) system inspired by the philosophical and psychoanalytical concept of imagination as a ``Re-construction of Experiences". Our AI system is equipped with an imagination-inspired module that bridges the gap between textual inputs and other modalities, enriching the derived information based on previously learned experiences. A unique feature of our system is its ability to formulate independent perceptions of inputs. This leads to unique interpretations of a concept that may differ from human interpretations but are equally valid, a phenomenon we term as ``Interpretable Misunderstanding". We employ large-scale models,... 

    Design and Implementation of a FlexRay Transceiver

    , M.Sc. Thesis Sharif University of Technology Sadat Mansoury, Hamid (Author) ; Atarodi, Mojtaba (Supervisor)
    Abstract
    With the advancement of automotive industry, the number of electronic systems that need to communicate with each other has increased. An effective strategy to meet these growing demands is using bus-based protocols, which can establish safe communication among numerous nodes with reasonable cost, weight, and space requirements. The objective of this thesis is the design and implementation of a transceiver based on the FlexRay protocol. The significance of this protocol lies in its ability to provide higher data transmission rates compared to other protocols like CAN and LIN, and its role as the foundational communication medium among various domains in modern vehicle architectures. In this... 

    Deformation and Annealing Behavior of an Austenitic Stainless Steel

    , M.Sc. Thesis Sharif University of Technology Sadat Alavi, Parisa (Author) ; Serajzadeh, Siamak (Supervisor)
    Abstract
    In this research, non-isothermal annealing process at temperatures ranging between 400°C to 830 °C was investigated in warm and cold-rolled austenitic stainless steel 304L. First, the wide variety of austenitic to martensitic structure was produced by the multi-pass rolling process at room temperature -8 °C, 200 °C, and 280°C. The n exponent in Olson-Cohen equation was governed 2.83 after non-linear curve fitting to assess the fraction of deformation-induced martensite as a function of strain. Afterward, Abaqus/Explicit method was utilized to achieve the stored energy and plastic strains distribution through the thickness. Then, Cellular automata and Galerkin-finite element models were... 

    A fast and accurate gate model for small field scattering proton beam therapy

    , Article 15th IEEE International Symposium on Medical Measurements and Applications, MeMeA 2020, 1 June 2020 through 3 June 2020 ; 2020 Piruzan, E ; Vosoughi, N ; Mahani, H ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2020
    Abstract
    Proton beam therapy (PBT) is a modern external beam radiation therapy characterized by superior dose distribution. Small field PBT refers to the treatment of tumor sizes less than 7 cm in diameter. In this study, a fast and accurate GATE model was developed and then validated for a small field scattering PBT delivery. To this aim, a fixed single scattering nozzle was modeled in the GATE platform. To accelerate the GATE simulations, a variance reduction technique (VRT) was also incorporated by ignoring the tracking of the secondary particles having a range below a predefined cutoff. In addition, the influence of collimator material on the model performance was evaluated. Beam uniformity,... 

    Development and validation of an optimal GATE model for double scattering proton beam delivery

    , Article Journal of Instrumentation ; Volume 16, Issue 2 , 2021 ; 17480221 (ISSN) Piruzan, E ; Vosoughi, N ; Mahani, H ; Sharif University of Technology
    IOP Publishing Ltd  2021
    Abstract
    Proton therapy (PT) is an emerging external beam radiation therapy characterized by superior dose distribution compared to conventional modalities. In the present study, an optimal GATE model was developed and then validated for a double scattering proton nozzle based on the previously constructed model. To this aim, a double scattering treatment nozzle was modeled in the GATE platform. To accelerate the GATE simulations, a virtual range modulation wheel (vRMW) and a variance reduction technique (VRT) were implemented. Proton beam flatness, symmetry, and delivery efficiency, secondary neutron dose, and dosimetric performance were characterized through a set of GATE simulations. The findings... 

    A comprehensive survey of proton beam therapy research and development in Iran

    , Article Frontiers in Biomedical Technologies ; Volume 8, Issue 1 , 2021 , Pages 9-19 ; 23455829 (ISSN) Piruzan, E ; Vosoughi, N ; Mahani, H ; Sharif University of Technology
    Tehran University of Medical Sciences  2021
    Abstract
    Purpose: Proton Beam Therapy (PBT) is an emerging radiotherapy technique using beams of proton to treat cancer. As the first report addressing the topic, the principal aim is to highlight the present status of PBT research and development in Iran as a developing country. Materials and Methods: To do so, the demand for PBT in Iran and Iran National Ion Therapy Center (IRNitc) was investigated and introduced. Then, Scopus and PubMed were searched for studies that dealt with PBT research in Iran and subsequently 6 major subfields of interest were identified. Furthermore, international collaborations were extracted from the bibliographic data. To combine both research and development sides, a... 

    Modeling and optimization of respiratory-gated partial breast irradiation with proton beams - A Monte Carlo study

    , Article Computers in Biology and Medicine ; Volume 147 , 2022 ; 00104825 (ISSN) Piruzan, E ; Vosoughi, N ; Mahani, H ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    The selection of a suitable duty factor (DF) remains a major challenge in respiratory-gated treatments. Therefore, this study aims at presenting a new methodology for fast optimizing the gating window width (duty factor (DF)) in respiratory-gated proton partial breast irradiation (PBI). To do so, GATE Monte Carlo simulations were performed for various target sizes and locations in supine and prone positions. Three different duty factors of 20, 25, and 33% were considered. Sparing factors (SF) for four organs-at-risk (OARs) were then assessed. The weighted-sum method was employed to search for an optimal DF. The results indicate that an SF higher than unity was obtained for all plans. The SF...