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davari--narges
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Synthesis and Characterization of Vanadium (IV)-SNO & ONO Tridentate Schiff-Base Complexes and Their Applications in Sulfide and Alcohol Oxidation in Ionic Liquid Media
, M.Sc. Thesis Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor)
Abstract
In recent years, application of transition metal biphasic catalytic systems for different reactions is an area of intense research activity. Among these reactions, oxidation of sulfides to sulfoxides and sulfones due to their importance as an intermediate in synthesis of organic compounds is a center of interest. Also, the catalytic conversion of alcohols to the corresponding aldehydes or ketones is a fundamental transformation in both laboratory and industrial synthetic chemistry. From environmental perspectives, the development of new catalytic oxidation systems with molecular oxygen as green oxidant is particularly attractive. In recent years, ionic liquids have been extensively studied...
Agent-based Programming and it's Application Using GOAL
,
M.Sc. Thesis
Sharif University of Technology
;
Ramezanian, Rasoul
(Supervisor)
Abstract
With the significant advances in software engineering and developing complicated systems, it’s important to investigate the interaction between systems. Agentoriented software engineering is a new paradigm for developing distributed intelligent systems. Agent technology currently plays an important role in complex software development. The underlying paradigm offers a large repertoire of original concepts, architectures, interaction protocols, and methodologies for the analysis and the specification of complex systems built as Multi-Agent Systems (MAS). Several efforts, originating from academia, industry, and several standardisation consortium, have been made in order to provide new tools,...
Auto-selection of space-time Interest Points for Action Recognition
Application in Fisherposes Method
,
M.Sc. Thesis
Sharif University of Technology
;
Mohammadzadeh, Narges Hoda
(Supervisor)
Abstract
In this project, a novel action recognition method, named Fisherposes, is proposed, which is improved by several space-time (spatio-temporal) methods afterwards. The proposed method utilizes skeleton data obtained from Kinect sensor. First, pre-processing is performed in which the scales of bodies are canceled and the skeletons become aligned in order to make the method robust to location, orientation, and scale of people. In Fisherposes method, every action is defined as a sequence of body poses. Using the training samples for the poses, a Fisher subspace is created which we name it Fisherposes. Moreover, a novel distance measuring function, named regularized Mahalanobis distance, is...
Temporal Analysis of Functional Brain Connectivity Using EEG Signals
, M.Sc. Thesis Sharif University of Technology ; Mohammadzadeh, Narges Hoda (Supervisor)
Abstract
Human has different emotions such as happiness, sadness, anger, etc. Recognizing these emotions plays an important role in human-machine interface. Emotion recognition can be divided into approaches, physiological and non-physiological signals. Non-physiological signals include facial expressions, body gesture, and voice, and physiological signals include electroencephalograph (EEG), electrocardiograph (ECG), and functional magnetic resonance imaging (fMRI). EEG signal has been absorbed a lot of attention in emotion recognition because recording of EEG signal is easy and it is non-invasive. Analysis of connectivity and interaction between different areas of the brain can provide useful...
Quantum Dot Infrared Photodetector
, M.Sc. Thesis Sharif University of Technology ; Faez, Rahim (Supervisor)
Abstract
Conventionally all objects radiate most of its energy in the from of infrared waves, therefore, infrared photodetectors for detecting objects is important and more study is done on improve the detecting parameters. The proposed structures are developed from bulk to quantum well and quantum dots in recently years. In this work at reason insensitivity to incident light polarization, flexible operation wavelength, high operation temperature, inherent photovoltaic effect, low capture probability we study the structure of quantum dot infrared photodetectors and then for improve the detecting parameters structure of two layers quantum dot separated with a layer thin barrier (bilayer). And then a...
Numerical and Experimental Investigation of Thermally Driven Exchange Flow and Wind set up in Canopy Steep Area
, M.Sc. Thesis Sharif University of Technology ; Jamali, Mirmosaddegh (Supervisor)
Abstract
Solar heating in aqautic systems, causes tempreture increasing.This temperature difference will promote an exchange flow between the vegetation and open water. The exchange flow generated by the differential heating and cooling associated with depth variation has also been studied through laboratory experiment and modelling. Differential solar heating can result from shading by rooted emergent aquatic plants, producing a temperature difference between vegetated and unvegetated regions of a surface water body. Horizontal density difference between shaded and open water regions drives currents that carry fluxes between biologically and chemically distinct regions of an aquatic system. Such...
, M.Sc. Thesis Sharif University of Technology ; Jamali, Mirmossadegh (Supervisor)
Abstract
Preservation and survival of ecological systems by vegetation is important. A study focusing on the hydrodynamics of these complex ecosystems could help to explain the filtering ability of vegetation in wetlands and estuaries. Wetlands assist in flood control, shoreline protection, and groundwater recharge. In addition, they play a purification role in removing sediments and contaminants from polluted waters, nutrient uptake, and oxygen production.
Laboratory experiments have been designed to study the influence of marsh vegetation on lateral dispersion in flexible vegetation that has been modelled with inclined cylinder. The flow through vegetation is modelled by a circulating flow...
Laboratory experiments have been designed to study the influence of marsh vegetation on lateral dispersion in flexible vegetation that has been modelled with inclined cylinder. The flow through vegetation is modelled by a circulating flow...
Coexistense of Dirac and Weyl Fermions in Topological Semimetals
, M.Sc. Thesis Sharif University of Technology ; Kargarian, Mehdi (Supervisor)
Abstract
Dirac-Weyl semimetals are new topological phases hosting the coexistence of Dirac and Weyl points in momentum space. Due to the different symmetry requirements of Weyl and Dirac semimetals, one may wonder whether these phases can coexist in real materials. Based on first principles calculations the noncentrosymmetric compounds SrHgPb and CaHgSn have band structure with the Dirac-Weyl crossings. In this thesis we introduce four band minimal lattice models which preserve n-fold rotation along z axis and break inversion symmetry. The obtained models use the minimum number of degrees of freedom, spin and orbital, and proper symmetries relevant to real materials yielding a four-band model where...
Mog cosmology without dark matter and the cosmological constant
, Article Monthly Notices of the Royal Astronomical Society ; Volume 507, Issue 3 , 2021 , Pages 3387-3399 ; 00358711 (ISSN) ; Rahvar, S ; Sharif University of Technology
Oxford University Press
2021
Abstract
In this work, we investigate the MOdified Gravity (MOG) theory for dynamics of the Universe and compare the results with the Lambda cold dark matter (ΛCDM) cosmology. We study the background cosmological properties of the MOG model and structure formation at the linear perturbation level. We compare the two models with the currently available cosmological data by using statistical Bayesian analyses. After obtaining updated constraints on the free parameters, we use some methods of model selection to assist in choosing the more consistent model such as the reduced chi-squared (χ 2red) and a number of the basic information criteria such as the Akaike Information Criterion (AIC), the Bayes...
Null Controllability and Stabilizability of Compressible Navier-stokes System in One Dimension
, M.Sc. Thesis Sharif University of Technology ; Hesaraki, Mahmoud (Supervisor)
Abstract
In this thesis we study the exponential stabilization of the one dimensional compressible Navier-Stokes system, in a bounded interval locally around a constant steady state by a localized distributed control acting only in the velocity equation. In fact this is an analysis of a paper that published by Shirshendu Chowdhury, Debayan Maity, Mithily Ramaswamy and Jean-Pierre Raymond in Journal of Differential Equations. We determine a linear feedback law able to stabilize a nonlinear transformed system. Coming back to the original nonlinear system, we obtain a nonlinear feedback law able to stabilize locally this nonlinear system. The result is providing feedback control laws stabilizing...
Experimental and CFD Study of Physical Properties Effect on Hydrodynamic and Mass Transfer Coefficient of Single Drops
, M.Sc. Thesis Sharif University of Technology ; Bastani, Daruoosh (Supervisor)
Abstract
In present study, it is tried to investigate the effect of physical properties on hydrodynamic and overall mass transfer coefficient of single drops using different experiments and then simulation of drop motion with OpenFOAM software version 1.7.1. the systems were choosen are toluene/acetone/water and n-butanol/succinic acid/water which their interfacial tensions are 36 and 1.6 mN/m respectively. Various type of nozzles have been used for produce of 1.5, 2, 3 and 4 millimeter drops. The results show that in absence of solute component, the rising velocity of toluene drops in each size is higher than rising velocity of butanol drops inside the water between 25 to 75 percent. But with...
Embodiment Approach Used by a Quadruped Robot to Learn How to Walk
, M.Sc. Thesis Sharif University of Technology ; Bagheri Shouraki, Saeed (Supervisor)
Abstract
The researches done on legged robots can be categorized in two main groups: based on analytical methods and intelligent methods. All researched done by intelligent methods are similar in adaptation of learning methods. Robots can improve their actions with learning and there is no need to do an exact modeling of environment and system. Also this is adaptive to changes in system and environment. There are different approaches for studying intelligence in cognitive science. Embodiment approach focuses on body, its properties and connection to environment. Controller, morphology and environment effect doing the tasks in embodiment. Morphology contains sensors, shapes of elements, actuators and...
On the relationship between unsteady forces and shock angles on a pitching airplane model
, Article Scientia Iranica ; Volume 17, Issue 2 B , 2010 , Pages 102-107 ; 10263098 (ISSN) ; Soltani, M. R ; Sharif University of Technology
2010
Abstract
A series of supersonic visualization tests were performed on an airplane model in both static and dynamic pitching cases. After image processing, the wave angles originating from different parts of the model were carefully measured and averaged over several oscillation cycles. These findings were then compared with the corresponding normal force under similar conditions. The results reveal a hysteresis loop in variations of the model shock angles with instantaneous angles of attack during upstroke and down-stroke motions. In comparison with the normal force hysteresis loop, it has been found that there is an interesting relationship between the shape of the hysteresis loop of the shock angle...
Cosmological constrains on minimally and non-minimally coupled scalar field models
, Article Monthly Notices of the Royal Astronomical Society ; Volume 491, Issue 2 , 2020 , Pages 1920-1933 ; Marra, V ; Malekjani, M ; Sharif University of Technology
Oxford University Press
2020
Abstract
We study the minimally and non-minimally coupled scalar field models as possible alternatives for dark energy (DE), the mysterious energy component that is driving the accelerated expansion of the universe. After discussing the dynamics at both the background and perturbation level, we confront the two models with the latest cosmological data. After obtaining updated constraints on their parameters, we perform model selection using the basic information criteria. We found that the ACDM model is strongly favoured when the local determination of the Hubble constant is not considered and that this statement is weakened once local H0 is included in the analysis. We calculate the parameter...
Effects of plunging motion on unsteady aerodynamic behavior of an aircraft model in compressible flow
, Article Iranian Journal of Science and Technology, Transaction B: Engineering ; Volume 31, Issue 1 , 2007 , Pages 49-63 ; 03601307 (ISSN) ; Soltani, M. R ; Sharif University of Technology
2007
Abstract
Aspects of pitching and plunging motions on unsteady aerodynamic behavior of an aircraft model were studied. Extensive wind tunnel tests were performed on a standard dynamics model, SDM, oscillating in both pitch and plunge modes. Up to now, there has been little or no result on the plunging behavior of an aircraft or missile as a whole and the present experiments can be considered as one of the first attempts to study the compressible flow field over a model undergoing both pitching and plunging motions. The experiments involved measuring normal force and pitching moment of the model at Mach numbers of 0.4, 0.6 and 1.5 and oscillation frequencies of 1.25, 2.77 and 6.00 Hz. The longitudinal...
Application of Intensifying Wind Analysis in Time History Analysis of Tall Buildings
, M.Sc. Thesis Sharif University of Technology ; Esmail Pourestekanchi, Homayoon (Supervisor)
Abstract
The wind phenomenon has always caused significant damage to structures. Suffering from extensive damage and loss over the years has led researchers to establish the novel science of wind engineering. Wind engineering references introduce wind as an intricate dynamic and random phenomenon and encourage engineers to familiarize themselves with its exact effects on structures by utilizing the latest methods of structural analysis, such as time history analysis. In this research, the idea of a new method for time history analysis of tall buildings against the wind is proposed. In this method, the purpose is to determine the responses of the structure against any wind of any intensity and return...
On wind tunnel wall pressure fluctuations during an unsteady test of a fighter model
, Article 35th AIAA Fluid Dynamics Conference and Exhibit, Toronto, ON, 6 June 2005 through 9 June 2005 ; 2005 ; 9781624100598 (ISBN) ; Soltani, M. R ; Sharif University of Technology
2005
Abstract
An intensive experimental work was conducted to investigate variations of the wall pressure time history at different locations during the test of a fighter aircraft model in a sinusoidal pitching motion. The model used in this research was a standard dynamics model known as SDM. Dynamic data were taken at various combinations of reduced frequencies, mean angles of attack and oscillation amplitudes. Time variations of the static pressure at several locations on the wind tunnel wall have been recorded using sensitive pressure transducers. The results show that the wall pressure oscillation is highly affected by the model motion and varies with the free stream Mach number, oscillation...
Force and moment measurements on a fighter model in heaving motion
, Article 43rd AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, 10 January 2005 through 13 January 2005 ; 2005 , Pages 6197-6206 ; Soltani, M. R ; Sharif University of Technology
American Institute of Aeronautics and Astronautics Inc
2005
Abstract
Extensive wind tunnel tests have been conducted to study the unsteady aerodynamic behavior of a standard dynamics model, SDM, oscillating in plunge mode. The unsteady aerodynamic behavior of various missile and aircraft configurations under pitching motion has been studied so far. However up to now, there is little or no result on the plunging behavior of an aircraft or missile as a whole and the present experiments can be considered as one of the first attempts to study the compressible flowfield over an aircraft undergoing plunging motion. The experiments involved measuring the normal force and pitching moment of the model oscillating in plunge at Mach numbers of 0.4, 0.6 and 1.5 and...
Analysis of People Appearance Variation in Multi-Camera Networks
, M.Sc. Thesis Sharif University of Technology ; Behroozi, Hamid (Supervisor) ; Mohammadzadeh, Narges Hoda (Co-Supervisor)
Abstract
Analysis of people appearance variation in multi-camera networks for person re-identification or person retrieval is a very challenging problem due to the many intra-class variations between different cameras. Like any problem in the field of machine vision, it is generally divided into two parts. The first part is feature extraction and the second part is feature matching for person retrieval. So far, various methods have been proposed for the extraction of discriminative features, which are generally divided into three categories: stripe-based, patch-based, and body-based methods. However, methods based on stripes, although simpler, have performed better due to their greater compatibility...
Software Product Line Testing Optimization Based on Regression Test Techniques
, M.Sc. Thesis Sharif University of Technology ; Mirian Hosseinabadi, Hassan (Supervisor)
Abstract
A software product line is a set of products with common features. The design of this set is such that the core assets that are common features between products are implemented only once. All products in the product line use the core assets to reduce development costs. The number of products that can be produced in a software product line is exponential to the number of capabilities in the core assets and the set is very large, so the cost of testing the software product line will be very high. In the software product line testing, various methods have been provided to reduce costs, among which we can mention product prioritization and regression test techniques. In prioritization, the...