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sadeghian--mohammad
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Named Entity Recognition and Linking: A Hadith Narration Chain Study
, M.Sc. Thesis Sharif University of Technology ; Izadi, Mohammad (Supervisor)
Abstract
Recognizing people mentioned in the text of narrations, is of the main importance in validating narrations in narration analysis. The problem naturally reduces to two sub-problems: Firstly, named entities related to narrators in the text should be determined. Secondly, if they are ambigous, the purpose of each should be clearified. In this resaerch, it is tried to apply pre-trained language models in soultion of the first sub-problem. For the purpose of entity linking with entities in a KB, graph-based model is suggested
Fabrication and Characterization of Hybrid NanoComposites Based on Epoxy/NanoDiamond/CarbonFiber
, M.Sc. Thesis Sharif University of Technology ;
Abstract
Polymer composites, due to its exclusive properties, has a special place in industry. Epoxy resin with high adhesion property, low density, thermal stability and high chemical resistance has a special place as matrix in fabrication of high technology hybrid composites. Hybrid composites, due to its high strength and long fatigue life, used to reinforcing building structures and manufacturing fuselage. Layer and reactive structure near the firm core and wear-resistant of NDs, used to improvement of epoxy reisn and hybrid NanoComposite interphase properties. In this study, for improvement of the properties of hybrid NanoComposites, used the NDs in 0.25, 0.5 and 1 %wt with amine and carboxyl...
Experimental investigation of Pressure Distribution over Delta Wing in
Sub/supersonic Speed
,
M.Sc. Thesis
Sharif University of Technology
;
Soltani, Mohammad Reza
(Supervisor)
Abstract
Flow characteristics analysis over a wing, is one of the pioneer challenges in super and sub-sonic flow near flying objects. Taking into account of growing rate of low aspect ratio utilization, usually called Delta wings, investigation of vortex behavior over this wings is highly noticeable. In addition, the lack of research in this branch of Aerodynamics inside the country, considering it’s critical application, has doubled the importance of doing research in this filled. Experimental researches on super-sonic flow over a Delta wing is limited and there are not much accurate researches about vortexes in this category of wings. In this work, the main effort is to investigate the phenomena in...
Algebra of Operators and Observables in the Algebraic Theory of Quantum Fields and Their Generalization in the Presence of Gravity
, M.Sc. Thesis Sharif University of Technology ; Faraji Astaneh, Amin (Supervisor)
Abstract
In recent years, a series of deep connections have been found between the ideas that used to be in the Algebraic Theory of Quantum Fields and the important problems of High Energy and Fundamental Physics. In the 1960s and later, some people who were mostly closer to mathematicians were trying to formulate the basics and principles of Quantum Field Theory in mathematically precise way. Many and various efforts have been made in this direction. One of these important efforts has been the Algebraic Theory of Quantum Fields. The main motivation in the Algebraic Theory of Quantum Fields is to focus on the operators and observables of the theory and study the algebraic structure between them instead...
Investigation on Photocatalytic and Corrosion Properties of Titania-Graphene Nanocomposite Coated by Electrophoretic Method
, M.Sc. Thesis Sharif University of Technology ; Nemati, Ali (Supervisor) ; Sadeghian, Zahra (Supervisor)
Abstract
The main purpose of this research was functionalizing graphene, in order to achieve higher hydrophobicity, and producing nanocomposite of functionalized graphene and titanium dioxide by hydrothermal method, and sequently invastigation on photocatalytic properties of the powders and corrosion properties of EPD coated samples. Graphene oxide was synthesized by improved Hummers method and reduced and sequently was functionalized through the chemical process with hydrazine and octadecylamine respectively. Then the nanocomposite of functionalized graphene-titania was synthesized by use of titanium isopropoxide precursor and its photocatalytic properties were measured. The analysis of the...
Identification and Abnormal Condition Detection of a Cement Rotary Kiln
, M.Sc. Thesis Sharif University of Technology ; Fatehi, Alireza (Supervisor)
Abstract
One of the most important parts of a cement factory is the cement rotary kiln which plays a key role in quality and quantity of produced cement. In this part, the physical exertion and bilateral movement of air and materials, together with chemical reactions take place. Thus, this system has immensely complex and nonlinear dynamic equations. These equations have not worked out yet. Only in exceptional case; however, a large number of the involved parameters were crossed out and an approximation model was presented instead. This issue caused many problems for designing a cement rotary kiln controller. In this thesis, we employed a nonlinear system identification method for identification,...
The Kinetic Term of the Effective Action in the NJL Model in Background Magnetic Field at Finite Temperature and Chemical Potential
, M.Sc. Thesis Sharif University of Technology ; Sadooghi, Neda (Supervisor)
Abstract
Kinetic terms of effective action including derivative of classical field become significant, when we have a dynamical field.These terms have been calculated as a function of the fermionic propagator in NJL model, which is an effective model of QCD. In this thesis, after briefly reviewing
the effect of constant background magnetic field on the propagator considered by Ritus method, we explicitly determine the kinetic terms in terms of Ritus eigenfunctions. Finally, we numerically calculate these terms at finite temperature and chemical potential according to the imaginary time method
the effect of constant background magnetic field on the propagator considered by Ritus method, we explicitly determine the kinetic terms in terms of Ritus eigenfunctions. Finally, we numerically calculate these terms at finite temperature and chemical potential according to the imaginary time method
Separation of Oxygen from Gas Mixture of Carbon Dioxide and Oxygen with Cyclohexanol and Triethylene Glycol Liquid Membrane in the Presence of Metal Oxide Nanoparticles
, M.Sc. Thesis Sharif University of Technology ; Bastani, Daruoosh (Supervisor)
Abstract
In this research, the effect of feed flow concentration on the separation of gas mixture of carbon dioxide and oxygen was investigated by using supported liquid membrane in the presence of nano particles. In order to achieve this purpose, supported liquid membranes were prepared by impregnating a porous hydrophilic PVDF support with TEG, cyclohexanol, TEG/Fe3O4 nano particles and cyclohexanol/ Fe3O4 nano particles. Permeability and selectivity of mixed gases CO2 and O2 were examined at five different CO2 concentrations in feed flow, constant feed flow rate and constant total pressure difference.
In all tests, the permeance of carbon dioxide through cyclohexanol and TEG membranes was...
In all tests, the permeance of carbon dioxide through cyclohexanol and TEG membranes was...
Dynamics Modelingand Decentralized Control of Scalable Multi Agent Holonomic Systems
, M.Sc. Thesis Sharif University of Technology ; Sayyaadi, Hassan (Supervisor)
Abstract
Today, a new approach in the use of robots and the division of task between them to accomplish a specific mission or doing group exercises, has emerged. In fact, the main idea is that the multi agent robotic systems, soon is the most economically advantageous and will take variety of tasks that require distribution understanding of the environment (eg, search and rescue, surveillance, environmental monitoring and military operations). In recent years, the autonomous wheeled mobile robots, OMR, have special significance. This type of robots for independent control of translational and rotational motion, have the holonomic behavior dynamic that this means unlike other nonholonomic robots, be...
Identification, prediction and detection of the process fault in a cement rotary kiln by locally linear neuro-fuzzy technique
, Article 2009 International Conference on Computer and Electrical Engineering, ICCEE 2009, 28 December 2009 through 30 December 2009 ; Volume 1 , 2009 , Pages 174-178 ; 9780769539256 (ISBN) ; Fatehi, A ; Sharif University of Technology
2009
Abstract
In this paper, we use nonlinear system identification method to predict and detect process fault of a cement rotary kiln. After selecting proper inputs and output, an input-output model is identified for the plant. To identify the various operation points in the kiln, Locally Linear Neuro-Fuzzy (LLNF) model is used. This model is trained by LOLIMOT algorithm which is an incremental tree-structure algorithm. Then, by using this method, we obtained 3 distinct models for the normal and faulty situations in the kiln. One of the models is for normal condition of the kiln with 15 minutes prediction horizon. The other two models are for the two faulty situations in the kiln with 7 minutes...
Identification of nonlinear predictor and simulator models of a cement rotary kiln by locally linear neuro-fuzzy technique
, Article 2009 International Conference on Computer and Electrical Engineering, ICCEE 2009, 28 December 2009 through 30 December 2009, Dubai ; Volume 1 , 2009 , Pages 168-173 ; 9780769539256 (ISBN) ; Fatehi, A ; Sharif University of Technology
2009
Abstract
One of the most important parts of a cement factory is the cement rotary kiln which plays a key role in quality and quantity of produced cement. In this part, the physical exertion and bilateral movement of air and materials, together with chemical reactions take place. Thus, this system has immensely complex and nonlinear dynamic equations. These equations have not worked out yet. Only in exceptional case; however, a large number of the involved parameters were crossed out and an approximation model was presented instead. This issue caused many problems for designing a cement rotary kiln controller. In this paper, we presented nonlinear predictor and simulator models for a real cement...
Identification of nonlinear predictor and simulator models of a cement rotary kiln by Locally Linear Neuro-Fuzzy technique
, Article World Academy of Science, Engineering and Technology ; Volume 58 , 2009 , Pages 1121-1127 ; 2010376X (ISSN) ; Fatehi, A ; Sharif University of Technology
2009
Abstract
One of the most important parts of a cement factory is the cement rotary kiln which plays a key role in quality and quantity of produced cement. In this part, the physical exertion and bilateral movement of air and materials, together with chemical reactions take place. Thus, this system has immensely complex and nonlinear dynamic equations. These equations have not worked out yet. Only in exceptional case; however, a large number of the involved parameters were crossed out and an approximation model was presented instead. This issue caused many problems for designing a cement rotary kiln controller. In this paper, we presented nonlinear predictor and simulator models for a real cement...
Identification, prediction and detection of the process fault in a cement rotary kiln by Locally Linear Neuro-Fuzzy technique
, Article World Academy of Science, Engineering and Technology ; Volume 58 , 2009 , Pages 1128-1134 ; 2010376X (ISSN) ; Fatehi, A ; Sharif University of Technology
2009
Abstract
In this paper, we use nonlinear system identification method to predict and detect process fault of a cement rotary kiln. After selecting proper inputs and output, an input-output model is identified for the plant. To identify the various operation points in the kiln, Locally Linear Neuro-Fuzzy (LLNF) model is used. This model is trained by LOLIMOT algorithm which is an incremental tree-structure algorithm. Then, by using this method, we obtained 3 distinct models for the normal and faulty situations in the kiln. One of the models is for normal condition of the kiln with 15 minutes prediction horizon. The other two models are for the two faulty situations in the kiln with 7 minutes...
Chaos control in continuous mode of T-AFM systems using nonlinear delayed feedback via sliding mode control
, Article ASME International Mechanical Engineering Congress and Exposition, Proceedings ; Volume 11 PART A , 2008 , Pages 201-208 ; ISBN: 079184305X ; Salaried, H ; Alasty, A ; Sharif University of Technology
2008
Abstract
The taping mode Atomic Force Microscopic (T-AFM) can be assumed as a cantilever beam which its base is excited by a sinusoidal force and nonlinear potential interaction with sample. Thus the cantilever may cause chaotic behavior which decreases the performance of the sample topography. In order to modeling, using the galerkin method, the PDE equation is reduced to a single ODE equation which properly describing the continuous beam. In this paper a nonlinear delayed feedback control.is proposed to control.chaos in T-AFM system. Assuming model parameters uncertainties, the first order Unstable Periodic Orbits (UPOs) of the system is stabilized using the sliding nonlinear delayed feedback...
Microstructure-mechanical Properties Relationship of Transient Liquid Phase Bonded 304 Stainless Steel With a Co-based Interlayer
, M.Sc. Thesis Sharif University of Technology ; Ekrami, Ali Akbar (Supervisor)
Abstract
Stainless steels have many applications in different industries like chemistry, medicine and food production. So for using these alloys it is necessary to join them with appropriate method. In this research, microstructure-mechanical properties relationship of 304LC austenitic stainless steel transient liquid phase bonded using a Co-based interlayer was investigated. For this purpose, bonding was conducted at 1180 ℃ for different holding times. Microstructure of the joints was evaluated by optical microscopy (OM) and Scanning Electron Microscopy (SEM). The results showed that isothermal solidification (IS) was completed within 1800s and no intermetallic compound was formed in the joint area...
Crystallisation kinetics of hydroxyapatite thin films prepared by sol-gel process
, Article Advances in Applied Ceramics ; Volume 109, Issue 6 , Jul , 2010 , Pages 313-317 ; 17436753 (ISSN) ; Nemati, A ; Sadeghian, Z ; Sharif University of Technology
2010
Abstract
In this study, the crystallisation of nano hydroxyapatite (HA) films on stainless steel 316L was studied. The film was prepared by sol-gel technique. The process was started with preparation of an HA sol. After aging of the sol at room temperature, a stainless steel 316L substrate was dip coated and then was heat treated from 350 to 450°C at different periods of time in air. The crystallisation behaviour and the transformation-temperature-time diagram of HA films were achieved and analysed using the avrami equation. The results showed that the crystallisation of HA began at 250°C and was increased up to 450°C. The obtained HA film showed a nanostructure character with a suitable crystalinity...
Transient liquid phase bonding of 304 stainless steel using a co-based interlayer
, Article Science and Technology of Welding and Joining ; Volume 22, Issue 8 , 2017 , Pages 666-672 ; 13621718 (ISSN) ; Ekrami, A ; Jamshidi, R ; Sharif University of Technology
2017
Abstract
Transient liquid phase bonding of AISI 304 austenitic stainless steel was carried out using a Co-based interlayer with 40 μm thickness. The effect of bonding time and solid-state homogenisation time on the microstructure and mechanical properties of samples was investigated. The results showed that isothermal solidification was completed within 30 min at a constant temperature of 1180°C. With increasing homogenisation time, at 1000°C, a more uniform distribution of alloying elements and hardness profile across the joint region was achieved. The average shear strength of homogenised samples was about 72% that of the base metal at the same heat treatment cycle. © 2017 Institute of Materials,...
Chaos control in continuous mode of T-AFM systems using nonlinear delayed feedback via sliding mode control
, Article ASME International Mechanical Engineering Congress and Exposition, IMECE 2007, Seattle, WA, 11 November 2007 through 15 November 2007 ; Volume 11 PART A , 2008 , Pages 201-208 ; 079184305X (ISBN); 9780791843055 (ISBN) ; Salaried, H ; Alasty, A ; Sharif University of Technology
2008
Abstract
The taping mode Atomic Force Microscopic (T-AFM) can be assumed as a cantilever beam which its base is excited by a sinusoidal force and nonlinear potential interaction with sample. Thus the cantilever may cause chaotic behavior which decreases the performance of the sample topography. In order to modeling, using the galerkin method, the PDE equation is reduced to a single ODE equation which properly describing the continuous beam. In this paper a nonlinear delayed feedback control is proposed to control chaos in T-AFM system. Assuming model parameters uncertainties, the first order Unstable Periodic Orbits (UPOs) of the system is stabilized using the sliding nonlinear delayed feedback...
In vitro characterization of carbon-nanotube-reinforced hydroxyapatite composite coating on 316L stainless steel
, Article Journal of Ceramic Science and Technology ; Volume 4, Issue 3 , August , 2013 , Pages 163-168 ; 21909385 (ISSN) ; Nemati, A ; Sadeghian, Z ; Sharif University of Technology
2013
Abstract
This investigation focused on a comparison between hydroxyapatite (HA) and carbon-nanotube-reinforced hydroxyapatite composite (CNTs/HA) coatings. The HA and CNTs/HA composite (with 5wt% CNTs) coatings were prepared with the sol-gel method on 316L stainless steel. Phase evaluation by means of XRD and Raman spectroscopy was performed on the HA and CNTs/HA composite coatings. The coatings were immersed in simulated body fluid (SBF) in order to evaluate the biological properties of the coatings. During the first week of immersion, the increase in the amount of Ca2+ precipitation in the SBF when CNTs/HA was used was lower than for the HA coatings. This behavior can be related to the difference...
Inclusion of carbon nanotubes in a hydroxyapatite sol-gel matrix
, Article Ceramics International ; Volume 35, Issue 7 , 2009 , Pages 2987-2991 ; 02728842 (ISSN) ; Nemati, Z. A ; Sadeghian, Z ; Sharif University of Technology
2009
Abstract
In this study, the inclusion of multi-walled carbon nanotubes as the second phase in the hydroxyapatite matrix, in order to improve the mechanical strength, has been performed via the sol-gel process. The stability of carbon nanotube sol with the changes of pH and dispersant values (sodium dodecyl sulfate) was evaluated by zeta potential analysis. The results indicated that synthesis of hydroxyapatite particles in the presence of the carbon nanotubes had the best result in homogenization of the carbon nanotube dispersion and faster crystallization of hydroxyapatite. The crystallization of hydroxyapatite phase was investigated with differential scanning calorimetry (DSC) and X-ray diffraction...