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al-taha-motahar--narges-khatoon
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Modeling of Fischer-Tropsch Synthesis Reactor for GTL Process
, M.Sc. Thesis Sharif University of Technology ; Khorasheh, Farhad (Supervisor) ; Taghikhani, Vahid (Supervisor)
Abstract
There is a need from the natural gas and energy industries to seek for an economically attractive way of converting remote gas reserves into transportable products, such as high quality fuels or petrochemicals. A possible way for the conversion of natural gas to middle distillates is based on a three-step process. Firstly, production of syngas from natural gas. Secondly,catalytic conversion of syngas into hydrocarbons, mostly parafins from C5 to C100. (Fischer-Tropsch (F-T) synthesis). Thirdly, hydrocracking of the heavy paraffinic hydrocarbons to middle distillates. The F-T synthesis step is highly exothermic. In order to control the temperature within the reactor, when considering high...
Vibrational analysis of wavy carbon nanotube-reinforced composites
, Article Proceedings of the ASME Design Engineering Technical Conference, 28 August 2011 through 31 August 2011, Washington, DC ; Volume 7 , August , 2011 , Pages 371-377 ; 9780791854846 (ISBN) ; Ahmadian, M. T ; Sharif University of Technology
2011
Abstract
Characterization and simulation of carbon nanotubereinforced composites at large scale have been a concern of researchers in the past decade. This is due to the computational complication of considering many embedded carbon nanotubes (CNTs). However a simple meshing of organized CNT distribution in the matrix can ease this obstacle. In this study, a finite element approach is employed to investigate the elastodynamic behavior of a wavy CNTreinforced composite structure. A three dimensional structure with up to 6400 uniformly distributed wavy CNTs is embedded in a polymer matrix. Each wavy nanotube is represented by a set of beam elements. The effect of nanotube waviness and volume fraction...
Diverse Video Captioning Using Recurrent Neural Networks and Part of Speech
, M.Sc. Thesis Sharif University of Technology ; Mohammadzadeh, Narges Al Hoda (Supervisor) ; Behroozi, Hamid (Co-Supervisor)
Abstract
In recent years, the simultaneous analysis of image and text by artificial intelligence has gained much attention. Video description is one of the topics used to help the blind, automate video content analysis, and more. This issue is usually examined in the context of supervised learning and is very similar to image description and machine translation.The proposed solutions to this problem are mainly in the framework of encoder-decoder and attention-based neural networks. Selection of various pre-trained networks to extract 2D and 3D visual features (description of objects and actions in the image), various hierarchical structures and different teaching methods (based on reinforcement...
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...
Optimization of the machinability of powder extruded Al-SiC MM composite using ANN analysis and genetic algorithm
, Article Proceedings of the World Powder Metallurgy Congress and Exhibition, World PM 2010, 10 October 2010 through 14 October 2010 ; Volume 2 , 2010 ; 9781899072194 (ISBN) ; Shafiee Motahar, M ; Faghani, H ; Boroushaki, M ; Sharif University of Technology
European Powder Metallurgy Association (EPMA)
2010
Abstract
Metal matrix composites (MMCs) have received considerable attention due to their excellent engineering properties, but their poor machinability has been the main deterrent to their substitution for metal parts. Optimization of machining parameters such as cutting speed, feed rate and depth of cut will improve the machinability of this material. This paper represents application of artificial neural network (ANN) model and genetic algorithm to study the machinability aspects of Al/SiC-15% produced by powder metallurgy process and to obtain optimum machining conditions. A multilayer feed forward ANN has been employed to study the effect of machining parameters on three aspects of machinablity,...
Study the Books of Science and Physics Education in Iran from the Perspective of Current Philosophy of Science
, M.Sc. Thesis Sharif University of Technology ; Golshani, Mahdi (Supervisor)
Abstract
In this research, I intend to case study formal education textbook in Iran that responsible for educate science in elementary school or educate physics in high school that to study the situation of education in this field of knowledge in Iran. The method of this research is study the text of textbook and find instance that somehow build philosophy of science assumption in students’ minds. In the following, I categorize these founded phrase that find in all related books, following the current philosophy of science theories. In the end of this research, I present an explanation of these authors textbook’s assumption
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...
Dynamic and Vibration Analysis of Wavy Carbon Nanotube-Reinforced Composites
, M.Sc. Thesis Sharif University of Technology ; Ahmadiyan, Mohammad Taghi (Supervisor) ; Asghari, Mohsen (Supervisor)
Abstract
Characterization and simulation of carbon nanotube-reinforced composites at large scale have been a concern of researchers in the past decade. This is due to the computational complication of considering many embedded carbon nanotubes (CNTs). However a simple meshing of organized CNT distribution in the matrix can ease this obstacle. In this study, a finite element approach is employed to investigate the elastodynamic behavior of a wavy CNT-reinforced composite structure. A three dimensional structure with up to 6400 uniformly distributed wavy CNTs is embedded in a polymer matrix. Each wavy nanotube is represented by a set of beam elements. The effect of nanotube waviness and volume fraction...
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...
Deformation Analysis of Magnetic Elastomers using Finite Element Method
, M.Sc. Thesis Sharif University of Technology ; Naghdabadi, Reza (Supervisor) ; Sohrabpour, Saeed (Supervisor) ; Goudarzi, Taha (Co-Advisor)
Abstract
Magnetic elastomers are smart materials that consist of a combination of elastomeric matrix and magnetic particles. The mechanical and magnetic properties of this materials are changed by Applying an external magnetic field. The presence of an external magnetic field can cause these elastomers deform largely.Significant deformations of the magnetic elastomers, has made them suitable for a wide range of applications. The aim of this project is to solve the governing equations of magnetic elastomers with finite element method. Since there are no suitable models for the behavior of these elastomers in the commercial softwares, magnetic field module and solid mechanics module should be coupled...
Studying the Wisdom of Crowd Through Large-Scale Experiment & Statistical Simulations
, M.Sc. Thesis Sharif University of Technology ; Ejtehadi, Mohammad Reza (Supervisor) ; Yaseri, Taha (Co-Supervisor)
Abstract
In this thesis, we have tried to study one of the most well known collective behavior phenomena known as the Wisdom of the crowd, from the perspective of statistical physics. In recent decades with the appearance of Social Networks and mass media, collective social phenomena have become a critical topic in the life of every human being. In the Wisdom of crowd phenomenon, the overall process is to ask the crowd’s opinion regarding a special topic and after aggregating the predicted values, the aggregated quantity is declared as the wisdom of the crowd. It has been observed that in some polls and elections, the result of the wisdom of crowd outperforms every individual of the group and in some...
Multiscale Multiphysics Analysis of Deformable Microwave Metasurfaces Under Large Deformations and Prototype Fabrication
, Ph.D. Dissertation Sharif University of Technology ; Naghdabadi, Reza (Supervisor) ; Sohrabpour, Saeed (Supervisor) ; Goudarzi, Taha (Co-Supervisor)
Abstract
Electromagnetic metamaterials are designed artificial materials with sub-wavelength resonant inclusions. They can exhibit extraordinary properties such as negative permittivity, negative permeability, and anomalous reflection/refraction. Metasurfaces are 2D counterparts of metamaterials. Here, we proposed a framework for the multiscale multiphysics analysis of deformable metasurfaces. Nonlinear mechanical analysis (Geometry and material behavior), periodic boundary conditions, homogenization, multiscale analysis, and electromagnetic analysis are implemented in this framework. Benefiting from the framework, we proposed a multifunctional hyperelastic structured surface that can generate...
Time-course investigation of postural sway variability: Does anxiety exacerbate the sensory reweighting impairment in chronic stroke survivors?
, Article Neuropsychologia ; Volume 127 , 2019 , Pages 185-194 ; 00283932 (ISSN) ; Azad, A ; Mehdizadeh, H ; Doostdar, A ; Hoseinpour, F ; Mehdizadeh, M ; Niazi Khatoon, J ; Shokouhyan, M. R ; Parnianpour, M ; Taghizadeh, G ; Khalaf, K ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Although anxiety is one of the most prevalent psychological disorders in stroke survivors, its effect on sensory reweighting has not yet been fully studied. The aim of this work was to investigate how anticipation of collision avoidance events affects sensory reweighting in chronic stroke survivors with low and high levels of anxiety (LA-stroke and HA-stroke, respectively), as compared with healthy controls (HC), under the condition of perturbed proprioception. Eighteen LA-stroke and 18 HA-stroke survivors, as well as 18 gender- and age-matched HC, participated in this study. Postural sway variability (i.e. Root Mean Square (RMS) of the COP velocity) was measured for a duration of 180 s...
Analyzing Dermatological Data for Disease Detection Using Interpretable Deep Learning
, M.Sc. Thesis Sharif University of Technology ; Rabiee, Hamid Reza (Supervisor) ; Sharifi Zarchi, Ali (Supervisor) ; Ghandi, Narges (Co-Supervisor)
Abstract
We present a deep neural network to classify dermatological disease from patient images. Using self-supervised learning method we have utilized large amount of unlabeled data. We have pre-trained our model on 27000 dermoscopic images gathered from razi hospital, the best dermatological hospital in Iran, along with 33000 images from ISIC 2020 dataset. We have evaluated our model performance in semi-supervised and transfer learning approaches. Our experiments show that using this approach can improve model accuracy and PRC up to 20 percent on semi-supervised setting. The results also show that pretraining can improve classification PRC up to 20 percent on transfer learning task on HAM10000...
Cytochrome 4z1 expression is correlated with poor prognosis in patients with cervical cancer
, Article Current Oncology ; Volume 28, Issue 5 , 2021 , Pages 3573-3584 ; 17187729 (ISSN) ; Alshammari, F. O. F. O ; Youssef, A. M. M ; Al Sarayra, Y. M ; Al Saraireh, R. A ; Al Muhaisen, G. H ; Al Mahdy, Y. S ; Al Kharabsheh, A. M ; Abufraijeh, S. M ; Al Rawashdeh, H. M ; Sharif University of Technology
MDPI
2021
Abstract
Background: cervical cancer is one of the most common malignancies in women worldwide and its management remains challenging and complex. As Cytochrome4Z1 (CYP4Z1) is overex-pressed in many tumours, its expression in cervical cancer is unknown. Therefore, the present study aimed to evaluate CYP4Z1 expression in cervical cancers. Methods: CYP4Z1 expression was immunohistochemically assessed in 100 cases of cervical cancers along with ten normal cervix tissues, and the enzyme’s relationship to several clinicopathological features and survival was explored. Results: CYP4Z1 was strongly expressed in 55% of cervical cancer patients. Normal cervix samples were negative for CYP4Z1 expression....
Experimental study of the effects of IFT and hysteresis on resistivity and capillary pressure of carbonate rocks
, Article Energy Sources, Part A: Recovery, Utilization and Environmental Effects ; Volume 37, Issue 12 , May , 2015 , Pages 1346-1353 ; 15567036 (ISSN) ; Masihi, M ; Al Ajmi, A ; Al Wahaibi, T ; Al Wahaibi, Y ; Sharif University of Technology
Taylor and Francis Inc
2015
Abstract
Characterizing the electrical resistance of the formation rock is of great importance in, for example, interpreting the well log data, calculating the porosity, and water saturation for the formation rocks. The relation between the resistivity factor and porosity and also between the resistivity index and water saturation (Archie equation) in the formation rock uses the parameters, such as the cementation factor and saturation exponent. However, the direct application of Archie equation to carbonate rocks that are very heterogeneous and mostly oil-wet needs further investigation. In this experimental work, the effects of overburden pressure, temperature, and interfacial tension on the...
Effect of nanofluid treatment on water sensitive formation to investigate water shock phenomenon, an experimental study
, Article Journal of Dispersion Science and Technology ; Volume 35, Issue 7 , 21 May 2014 , Pages 889-897 ; Heidari, M. A ; Al-Hadrami, H ; Al-Ajmi, A ; Al-Wahaibi, Y ; Ayatollahi, S ; Sharif University of Technology
21 May 2014
Abstract
Permeability reduction in porous media as a result of frail and tenuous fine particles migration would decrease the productivity index in the subterranean reservoirs. During reservoir stimulation by injecting fluids into the reservoir, as the salinity condition of the formation brine changes, fine particles initiate the triggering process. In this study, MgO-based nanofluid as a fines fixation agent was stably prepared based on the particle size distribution and characterized through transmission electron microscopy analysis. Afterward, several core flooding tests were performed using Berea sandstone cores to study the effect of nanofluid injection on fines fixation in the water shock...