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esmaeeli--siamak
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Reduced memory requirement in hardware implementation of SVM classifiers
, Article ICEE 2012 - 20th Iranian Conference on Electrical Engineering, 15 May 2012 through 17 May 2012 ; May , 2012 , Pages 46-50 ; 9781467311489 (ISBN) ; Gholampour, I ; Sharif University of Technology
2012
Abstract
Support Vector Machine (SVM) is a powerful machine-learning tool for pattern recognition, decision making and classification. SVM classifiers outperform other classification technologies in many applications. In this paper, two implementations of SVM classifiers are presented using Logarithmic Number System. In the basic classifier all operations (multiplication, addition and ...) are performed using logarithmic numbers. In the logarithmic domain, multiplication and division can be simply treated as addition or subtraction respectively. The main disadvantage of LNS is the large memory requirement for high precision addition and subtraction. In the improved classifier, multiplication...
American options with asymmetric information and reflected BSDE
, Article Bernoulli ; Volume 24, Issue 2 , May , 2018 , Pages 1394-1426 ; 13507265 (ISSN) ; Imkeller, P ; Sharif University of Technology
International Statistical Institute
2018
Abstract
We consider an American contingent claim on a financial market where the buyer has additional information. Both agents (seller and buyer) observe the same prices, while the information available to them may differ due to some extra exogenous knowledge the buyer has. The buyer's information flow is modeled by an initial enlargement of the reference filtration. It seems natural to investigate the value of the American contingent claim with asymmetric information. We provide a representation for the cost of the additional information relying on some results on reflected backward stochastic differential equations (RBSDE). This is done by using an interpretation of prices of American contingent...
Location and Scheduling Trucks at Cross Docking Systems
, M.Sc. Thesis Sharif University of Technology ; Hajji, Alireza (Supervisor)
Abstract
Given the increased competition in supply chains and enlargement of their scale along with increasingly significant role of distribution systems, design and optimization of novel systems with comprehensive approaches in a timely manner has become important more than ever. One of such modern, efficient systems is cross docking in which the distribution network is omitted and thus operations are carried out faster and the productivity is increased. In this system, processes like packaging is done in cross docking and the goods and products are directly sent to customers. This study investigates a long-term and a short-term approach to the design of in two distinct problems. In the first...
Storage of Information in Chemical Compounds
, M.Sc. Thesis Sharif University of Technology ; Shafiee, Afshin (Supervisor)
Abstract
Regarding the notable progress in communication and competition theories as well as natural sciences, the study of the concepts of information has displayed more attention in recent years.Information, entropy and energy are interrelated concepts. In one hand one can infer that entropy is a quantitation measure of information and on the other hand systems which carry information can accumulated energy.Here, we are going to survey the qualitation as well as quantitation aspects of information with concentration on the behavior of chemical agents as information processors
Electrodeposition and Characterization of Zn-Ni-Mn Coatings
, M.Sc. Thesis Sharif University of Technology ; Ghorbani, Mohammad (Supervisor)
Abstract
In this study, the electrochemical precipitation of three-component zinc-nickel-manganese coating on st37 steel substrate from chloride bath was investigated. Cyclic voltammetry results showed that the presence of ammonium thiocyanate complexer had a positive effect on the stability of precipitated manganese. Also, in order to evaluate the optimal coating conditions, the precipitation process at voltages of -1.4, -1.5 and VSCE -6.6, concentration of zinc 0.3 M, concentration of nickel 0.15 M and concentrations of manganese 0.15, 0.3 And 0.45 M and temperatures of 25, 40 and 55 .C. The results of X-ray energy diffraction spectroscopy, atomic absorption spectroscopy and X-ray diffraction of...
Dynkin game with asymmetric information
, Article Bulletin of the Iranian Mathematical Society ; Volume 45, Issue 1 , 2019 , Pages 283-301 ; 10186301 (ISSN) ; Imkeller, P ; Nzengang, V ; Sharif University of Technology
Springer International Publishing
2019
Abstract
We consider a Dynkin game where the seller possesses additional information compared to the buyer. The additional information is described by a random variable taking finitely many values. We show that the game possesses a value and we provide a necessary and sufficient condition for the existence of a Nash equilibrium. Results are illustrated with an explicit example. © 2018, Iranian Mathematical Society
A multi-bit error tolerant register file for a high reliable embedded processor
, Article 2011 18th IEEE International Conference on Electronics, Circuits, and Systems, ICECS 22011, 11 December 2011 through 14 December 2011 ; December , 2011 , Pages 532-537 ; 9781457718458 (ISBN) ; Hosseini, M ; Vahdat, B. V ; Rashidian, B ; Sharif University of Technology
2011
Abstract
The vulnerability of microprocessors to soft errors is increasing due to continuous shrinking in fabrication process. Recent studies show that 1-5% of the SEUs (single event upset) can cause MBUs (multiple bit upsets). The probability of MBU generation due to SEU is increasing because of the reduction in minimum energy required to flip a memory bit in modern technologies. Register file is the most sensitive component in a microprocessor. In this paper, we present an innovative way to protect registers in a 64-bit register file for a RISC processor using extended Hamming (8, 4) code (SEC-DED code) and narrow-width values. A narrow-width value can be represented by half number of bits of the...
Design of a Fault Tolerant ARM-Based Processor on FPGA
, M.Sc. Thesis Sharif University of Technology ; Rashidian, Bijan (Supervisor) ; Vosughi Vahdat, Bijan (Supervisor)
Abstract
The charged particles in space strike the silicon surface of an embedded system in a satellite and cause fault occurrence in its operation. So some methods should be employed to reduce the effects of the faults. The methods that are implemented in system level are widely used because of their low cost and high reliability. The processors are responsible for performing main processes in embedded systems. On the other hand, the ARM processors are good choices for utilizing in satellites because of their low size, low power consumption and high performance. Also, FPGAs have made a major improvement in embedded system design. So with implementing ...
Structural and transport properties of polydimethylsiloxane based polyurethane/silica particles mixed matrix membranes for gas separation
, Article Korean Journal of Chemical Engineering ; Volume 31, Issue 5 , 2014 , Pages 841-848 ; ISSN: 02561115 ; Ghalei, B ; Fardi, M ; Esmaeeli, M ; Vakili, E ; Sharif University of Technology
2014
Abstract
Mixed matrix membranes of synthesized polyurethane (PU) based on toluene diisocyanate (TDI), polydimethylsiloxane (PDMS) and polytetramethylene glycol (PTMG) with polyvinyl alcohol based polar silica particles were prepared by solution casting technique. The homogeneity and thermal properties of the prepared PDMS-PU/silica membranes were characterized using scanning electron microscope (SEM), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The SEM micrographs confirmed the distribution of silica particles in the polymer matrix without agglomerations. Gas permeation properties of membranes with different silica contents were studied for pure CO2, CH4, O2, He...
American and Game Contingent Claims with Asymmetric Information and Reflected BSDE
, Ph.D. Dissertation Sharif University of Technology ; Zohouri Zangeneh, Bijan (Supervisor) ; Foroush-Bastani, Ali (Co-Advisor)
Abstract
In the past decades, an extensive mathematical theory has been developed for the problems of derivative pricing. One of the salient features of this theory is its assumption of a common information flow on which the portfolio decisions of all economic agents are based. In this thesis, we attempt to widen the scope of the pricing financial derivatives by studying two important classes of contingent claims in a financial market with two types of investors on different information levels. Following the well-known link between optimal stopping problems and reflected backward stochastic differential equations (RBSDE) in El Karoui et al. [31], we also investigate the problem of information...
A study on Warm Rolling Behavior of an Austenitic Stainless Steel and the Mechanical Properties of the Rolled Product
, M.Sc. Thesis Sharif University of Technology ; Serajzade, Siamak (Supervisor)
Abstract
In this study, thermo-mechanical behavior of an austenitic stainless steel AISI316L was investigated using mathematical modeling and experimental analysis during warm rolling process. First, the thermo-mechanical analysis was carried out employing the finite element software, Abaqus CAE, to assess temperature, strain, velocity and stress distribution during rolling. Then, rolling operations on 316L austenitic steel were performed under different working conditions while mechanical testing as well as microstructural observations were made on the rolled steels. Using simulation results and practical data, microstructural events and mechanical properties after warm rolling of stainless steel...
Prediction of Temperature and Strain Distribution in the Warm Rolling of Austenite Stainless Steel
, M.Sc. Thesis Sharif University of Technology ; Serajzadeh, Siamak (Supervisor)
Abstract
In this research, the hot and warm rolling of stainless steel 304 was studied. First the rolling process was simulated using Finite Element Method software ABAQUS and the distribution of temperature and strain in the process under discontinuous conditions were predicted. Next, hot and warm rolling of stainless steel 304 under different conditions was carried out. Specimens were cut and subject to mechanical testing, metallography and electron microscopic studies. Data obtained from these experiments and the predicted trends from ABAQUS were compared, therefore studying the effect of different parameters on the microstructure and mechanical properties of the rolled specimen. Results indicate...
Theoretical and Experimental Investigation of Warm Rolling of Al Alloy 2017
, M.Sc. Thesis Sharif University of Technology ; Serajzadeh, Siamak (Supervisor)
Abstract
A mathematical model was developed to assess thermomechanical behavior of work rolls during warm rolling processes of AA2017. A combined finite element analysis-slab method was first developed to determine thermal and mechanical responses of the strip being rolled under steady-state conditions; Then, the calculated roll pressure and temperature field were utilized as the governing boundary conditions for the thermomechanical problem of the work roll. Finally, the thermomechanical stresses within the work rolls were predicted by a thermoelastic finite element approach. The results indicate that, in warm strip rolling, thermal and mechanical stresses developed in the work rolls are comparable....
Thermo-mechanical Simulation of Warm Rolling of 6061 Al Alloy Using Finite Element and Upper Bound Methods
, M.Sc. Thesis Sharif University of Technology ; Serajzadeh, Siamak (Supervisor)
Abstract
In this research, temperature distribution and roll force during steady state warm and hot rolling of 6061 Al alloy strip have been simulated, using finite element method and upper bound solution. At first, the velocity field and deformation zone shape have been determined, by means of upper bound solution, then using 2D finite element method, the temperature distribution within rolling and considering rate of heat of deformation, has been calculated. This model generalized for two pass steady state warm and hot rolling. Also, in order to evaluate the predictions, the experimental recorded of temperature variation, during hot rolling and temperature variation predicted by model has been...
Simulation of Non-isothermal Austenite to Ferrite Transformation by Using Cellular Automaton Method
, M.Sc. Thesis Sharif University of Technology ; Serajzadeh, Siamak (Supervisor)
Abstract
In this study, transformation of austenite to ferrite under continuous cooling condition of a low carbon steel was investigated. In the first step, a heat transfer model was employedconsidering governing heat transfer boundary conditions and a microstructure model based on Cellular Automaton method was used simultaneouslyto predict austenite to ferrite transformation progress. The influence of pre-heating temperature and primary austenite grain size on the final ferrite grain size and distribution were perdected. To verify the simulation results, experimental processes were utilized. The microstructure distribution was determined by means of Clemex Pro software then, these results were...
Study of Microstructure and Mechanical Properties of Austenitic Stainless Steel after Sheet Rolling Process
, M.Sc. Thesis Sharif University of Technology ; Serajzadeh, Siamak (Supervisor)
Abstract
Austenite in the 300 stainless steels is not a table phase in deformation processing during which martensite phase forms. This causes significant changes in the microstructures as well as the mechanical properties of deformed steel. In this work, the effects of rolling speed, reduction, temperature and strain pass on the strain-induced martensite during strip rolling operation of stainless steel 304L are studied. Cold rolling experiments under different speeds, reduction and temperature are conducted and then, the microstructural events and mechanical properties of the rolled steel are evaluated. For doing so, different testing techniques including tensile test, hardness measurement, optical...
Softening Kinetics Prediction of Cold Worked Aluminum Alloy
, M.Sc. Thesis Sharif University of Technology ; Serajzadeh, Siamak (Supervisor)
Abstract
In this work, annealing procedure of cold-deformed AA5052-SiC composite has been simulated by using cellular automata approach and the effect of SiC second phase on softening kinetics has been studied. To do so, site saturated nucleation has been employed to establish initial microstructure. In addition, topological changing due to deformation has been implemented on the microstructure. During annealing, recovery and recrystallization phenomena occur simultaneously, and it has strong effect on the annealed microstructure. Therefore, during annealing, recrystallization and recovery has been considered simultaneously and decreasing in the stored energy, which has developed during deformation...
Investigation on Thermo-mechanical Behavior of AA5086 During Warm and Hot Rolling Operation
, M.Sc. Thesis Sharif University of Technology ; Serajzadeh, Siamak (Supervisor)
Abstract
A mathematical model has been proposed to estimate the deformation pattern and the required power in cold plate rolling using the stream function method and upper bound theorem. In the first place admissible velocity distributions as well as the geometry of deformation zone were derived from the proposed stream functions. Then, the optimum velocity field was obtained by minimization of the power function computed based on the upper bound theorem. Then a steady state heat transfer equation has been solved in whole model using finite element method. In order to verify the predictions, rolling experiments on aluminum plates were conducted and also, a finite element analysis performed employing...
Theoretical and Experimental Investigations of Deformation Behavior from Stainless Steel 304L During Rolling at Evelated Temperatures
, M.Sc. Thesis Sharif University of Technology ; Serajzadeh, Siamak (Supervisor)Effect of Strain Path on Static Recrystallization Behavior of a Steel
, M.Sc. Thesis Sharif University of Technology ; Serajzadeh, Siamak (Supervisor)
Abstract
Static recrystllization in low carbon steel after two type of deformation –sidepress as an inhomogeneous deformation and rolling as a common industrial process - has been simulated using Cellular Automata (CA). The finite element method was utilized to compute the strain and stored energy distribution due to deformation. The initial microstructures were created by simulation of recrystallization with homogeneous site-saturated nucleation and topologic deformation was also considered in model. Subsequently using the result of FEM, stored energy of deformation was calculated and transferred into a two dimensional CA lattice. Nucleation rate and grain boundary velocity were considered...