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khademi--ehsan
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Investigating the Relation of Individualistic/Collectivistic Culture on Constructive thougt Patterns Strategies
, M.Sc. Thesis Sharif University of Technology ; Khademi, Mahshid (Supervisor)
Abstract
Self-leadership” is a process through which individuals control their performance and lead themselves by using specific behavioral and cognitive strategies (Manz, 1986; Manz and Neck, 2004). This concept includes a toolkit of behavioral activities borrowed from social cognitive theory and goal setting. It also includes constructive thought processes that have been extensively studied in sports psychology. Scholars have categorized the SL (self-leadership) strategies into three main categories; behavioral, natural reward and constructive thought Strategies. (Neck and Houghton, 2006) Given the growing importance of self-leadership in contemporary organizations operating in an increasingly...
A Study of Trade and Transportation Trends in Asia
, M.Sc. Thesis Sharif University of Technology ; Vaziri, Manouchehr (Supervisor)
Abstract
Considering the extensive developments achieved up to now in the fields of trade and international transportation, as well as the key role of the freight transportation in the economical development of a zone or a country, the present research, titled “A Study of the Trade and Transportation Trends”, was planned. The available data concerning the trade of six types of the goods according to The United Nations Classification (SITC), within the period 1965-2005, have been analyzed in this research. The study has been focused on the Asian Multimodal Network constituted of 31 countries. Trading centre of each country in the selected network is assumed to be located in its capital town. The...
Synthesis, Characterization and Field Emission Study of Molybdenum Oxide (MoOx)Nanostructures
, M.Sc. Thesis Sharif University of Technology ; Moshfegh, Alireza (Supervisor)
Abstract
Different molybdenum oxide nano/micro structure thin films were synthesized by thermal evaporation method under various growth conditions such as deposition time, temperature and evaporation source-substrate distance. Molybdenum oxide nanostructures grown on Si(100) such as nanowalls, nanostars and nanowires were characterized with scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), atomic force microscopy (AFM) and high resolution transmission electron microscopy (HRTEM). Shape and type of nanostructures were determined with SEM, AFM and HRTEM analysis. XPS analysis showed that the synthesized nanostructures contained Mo6+, Mo5+, Mo4+ and...
Recommender Systems Based on Community Structure among Users and Items
, M.Sc. Thesis Sharif University of Technology ; Jalili, Mahdi (Supervisor)
Abstract
Mankind with it’s finite resources (Time, Energy, …) cannot make use of every accessible option in daily activities (such as buying items, listening to music and reading news), and is restricted to decide on a handful of them. Available options are increasing on a daily basis and these surplus of available options had an adverse effect; Thus, leading us to more baffling situations. As a result, need for external assistance appeared in decision situations. Considering exceptional computation power available to computers, a framework named Recommender Systems were developed. Recommender systems try to use their accessible data in order to make fitting suggestions to users. Personalization and...
Network Design Problem to Prevent Chaotic Flow
, M.Sc. Thesis Sharif University of Technology ; Pourzahedi, Hossein (Supervisor)
Abstract
Two significant features of a transportation network, uncertainty and complexity, might cause some irregular behaviors. One example of such behaviors is chaotic flow in which the transportation system fails to reach equilibrium and people experience different daily travel times. These uncertainties are not controllable in any transportation system and, if not taken into consideration, will result to low levels of service and poor reliability. In this study, an evolutionary traffic assignmet model is used to illustrate when the network reaches bifurcation and chaos. Later, the effects of uncertainty in the parameters of supply and demand is tested on the evolutionary traffic assignment model....
Investigating the Effects of the Length of Yielding Area In Buckling-Restrained Braces
, M.Sc. Thesis Sharif University of Technology ; Mofid, Masood (Supervisor)
Abstract
Structures having buckling restrained braces (BRB) as earthquake resisting system, have the qualities of high lateral stiffness and the ability to damp the energy coming from earthquake, at the same time.In addition to new structures, these braces can also be used in rehabilitating old steel or concrete buildings. By using this kind of resisting system, smaller sections are needed in design of buildings and also the cost of repair after earthquake can be highly reduced.The most important advantage of buckling restrained braces is their equal behavior and capacity in both tention and compression, that causes high energy absorption as a result of symmetric and stable cyclic behavior. All these...
Time Accurate 3D Analysis of Liquid Jet Breakup Dynamics Using the Image Analysis Techniques
, M.Sc. Thesis Sharif University of Technology ; Farshchi, Mohammad (Supervisor)
Abstract
The liquid breakup analysis and spray characteristics measurement of atomizer are very essential for the numerical modeling of the primary atomization in combustion chambers. The atomization process is irregular and random nature and is a chaotic phenomenon. This study was motivated by the lack of temporal analysis of the breakup process especially for the first and second wind-induced breakup regimes and the atomization regime. The aim of this study was to determine the location, velocity and structures of breakup liquid jet at different outlet pressures from 0.3 bar to 50 bar. The results indicate that the breakup length, ligament size, and the breakup time period are randomly varied in...
HPASC – OPCC bi-surface Shear Strength Prediction Model Using Deep Learning
, M.Sc. Thesis Sharif University of Technology ; Toufigh, Vahab (Supervisor)
Abstract
Selecting a suitable material is crucial for repairing the old concrete structures and joining precast panels of bridges, especially the bond strength between the substrate concrete and the overlay material. In this regard, this research focused on high-performance alkali-activated slag concrete (HPASC) as a new concrete used as an overlay on ordinary Portland cement concrete (OPCC) as a block of old concrete. Approximately four hundred bi-surface shear (BSS) tests were performed to evaluate the interface properties of OPCC and HPASC. HPASC specimens were designed with different NaOH molarity, silica fume (SF) content, steel fiber content, age of repair material, and proportion of grooved...
Examining the Effect of Patent Registration on the Attraction of Venture Capital: the Moderating Role of Collaborative Patents In the Field of Artificial Intelligence
,
M.Sc. Thesis
Sharif University of Technology
;
Miremadi, Iman
(Supervisor)
Abstract
Artificial intelligence is a field that has made another revolution in the Fourth Industrial Revolution and has become one of the most widely used emerging technologies in the present era. Further investigation of the trends in this field shows that it has shown increasing growth in recent years. Also, in the future, this trend will continue and fundamental changes will occur in societies. For this reason, countries must definitely pay the necessary and sufficient attention to this field in their growth and development path. To achieve this growth path, it is intended to evaluate the status of leading countries in the field of artificial intelligence using two key variables in technological...
Single-quantum interferometry: Which-way versus which-phase information stored in an ancillary quantum system
, Article Journal of Physics A: Mathematical and Theoretical ; Volume 52, Issue 40 , 2019 ; 17518113 (ISSN) ; Bahrampour, A. R ; Sharif University of Technology
Institute of Physics Publishing
2019
Abstract
In interferometers, the more information about a quantum's path that is available in an ancillary quantum system (AQS), the less visibility the interference has. By use of Shannon entropy, we try to compare the amount of which-phase information with the amount of which-way information stored in the AQS of two-path interferometers with symmetric beam merging. We show that the former is less than or equal to the latter if the bipartite system of the single quantum and the AQS is initially prepared in a pure state and the interaction between the two parts is unitary. The equality holds when symmetry exists. No which-way information is obtained by the measurement that we use for extracting the...
Facial Expression Recognition Using Soft Computing
,
M.Sc. Thesis
Sharif University of Technology
;
Manzuri, Mohammad Taghi
(Supervisor)
Abstract
Human face-to-face communication is an ideal model for designing a multimodal/media human-computer interface (HCI). Recent advances in image analysis and pattern recognition open up the possibility of automatic detection and classification of emotional and conversational facial signals. Automating facial expression analysis could bring facial expressions into man-machine interaction as a new modality and make the interaction tighter and more efficient. In this research an accurate real-time sequence-based system for representation, recognition and analysis of low-intensity facial expressions and facial action uints (FAUs) is presented. The feature extraction is done using facial feature...
Separation of Xylene Isomers
, M.Sc. Thesis Sharif University of Technology ; Molaei Dehkordi, Asghar (Supervisor)
Abstract
Xylene isomers have similar boiling points and, therefore, their separation by conventional distillation is not practical. The industrial separation of these isomers is generally performed by adsorption or crystallization processes, which are very energy consuming. In this work, the various methods of the separation of these isomers have been reviewed and the equilibrium adsorption of these components in liquid phase using two commercial types of zeolite including Z-700 and Na-BETA as adsorbent at 15, 25, and 35 oC and an initial concentration range of up to 50 wt% as well as in single and binary solutions was investigated. It was found that Z-700 adsorbent has no selectivity for the binary...
Sustainable ammonia production from steam reforming of biomass-derived glycerol in a heat-integrated intensified process: Modeling and feasibility study
, Article Journal of Cleaner Production ; Volume 324 , 2021 ; 09596526 (ISSN) ; Lotfi Varnoosfaderani, M ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Currently, ammonia, as a clean and sustainable energy carrier, is intensively synthesized from its elements during the Haber-Bosch technology. This process requires a large amount of energy and emits numerous amounts of carbon dioxide, because hydrogen is dominantly produced from fossil fuels through reforming processes. Biomass-derived glycerol steam reforming is an attractive alternative to traditional reforming for reducing the dependence on hydrocarbon resources and mitigating climate change. This research aims to intensify a heat-integrated process for the co-production of ammonia and syngas from glycerol valorization. In this process, glycerol reforming continuously provides hydrogen...
Use of biomass-derived glycerol as an alternative to fossil fuels for aniline production: Energy saving and environmental aspects
, Article Fuel ; Volume 310 , 2022 ; 00162361 (ISSN) ; Lotfi-Varnoosfaderani, M ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Catalytic reduction of nitrobenzene is the leading technological step in aniline production. The hydrogen required for this stage, is dominantly produced from fossil fuels through reforming processes, which take much energy and emit large amounts of CO2. Biomass-derived glycerol steam reforming is an attractive alternative to traditional reforming to reduce the dependence on hydrocarbon resources and mitigate climate change. This research aims to analyze a mass- and heat-integrated multi-tubular membrane reactor, containing nitrobenzene hydrogenation (exothermic-side) and glycerol steam reforming (endothermic-side) for co-production of aniline and syngas. In this process, hydrogenation...
Numerical study to optimize the melting process of phase change material coupled with extra fluid
, Article AIAA Scitech Forum, 2020, 6 January 2020 through 10 January 2020 ; Volume 1 PartF , 2020 ; Darbandi, M ; Schneider, G. E ; Sharif University of Technology
American Institute of Aeronautics and Astronautics Inc, AIAA
2020
Abstract
Several methods have been proposed and explored to improve the performance of the energy storage unit. This work numerically investigates the melting process of a phase change material in a rectangular enclosure in presence of an auxiliary fluid considering different volume ratios. This investigation aims to obtain the volume ratio at which the amount of energy storage in the system becomes optimized for a specified time period. Oleic acid with a melting point of 13.5 °C is selected as the phase change material and water as a fluid with a higher density than oleic acid is chosen as the auxiliary fluid. Imposing the auxiliary fluid on top of the oleic acid, a displacement occurs between the...
A novel technique for audio signals watermarking in the wavelet and Walsh transform domains
, Article 2006 International Symposium on Intelligent Signal Processing and Communications, ISPACS'06, Yonago, 12 December 2006 through 15 December 2006 ; 2006 , Pages 171-174 ; 0780397339 (ISBN); 9780780397330 (ISBN) ; Ghaemmaghami, S ; Khademi, N ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2006
Abstract
This paper presents a novel approach to audio signals watermarking in the wavelet or the Walsh transform domain. The idea is to embed watermark data in the coefficients of some scales of the transform domain. The overall bit rate of this method is about 90 bps. Due to low computational complexity of the suggested approach, particularly in the Walsh domain, this algorithm can be implemented in real time. Experimental results show robustness of the proposed method in low SNRs and also against some typical attacks, such as MP3 compression, echo, filtering, etc. Subjective evaluation confirms transparency of the watermarked audio signals. © 2006 IEEE
Design and Implementation of a Distributed Planning System Prototype
, M.Sc. Thesis Sharif University of Technology ; Ghassem-Sani, Gholamreza (Supervisor)
Abstract
Planning is one of the most important branches of artificial intelligence. The goal of planning is automated production of sequence of actions (plans) for some specified tasks. However the computation done by planners is very time consuming and complicated. Distributing computation is one solution to overcome such difficulties. Distribution divides the load of process between a number of agents and increases robustness. The purpose of this project is to reduce the computational overhead of planning by the means of distributing the planning process between a numbers of planners. In the proposed method, we first divide a classical planning problem to two separate subproblems by decomposition...
Design algorithm evaluation of swirler-injector systems in liquid-burning combustion chambers
, Article 7th International Conference on Fluid Flow, Heat and Mass Transfer, FFHMT 2020, 15 November 2020 through 17 November 2020 ; 2020 , Pages 194-1-194-10 ; Mosadegh, S ; Khademi, A ; Sorrentino, G ; Sharif University of Technology
Avestia Publishing
2020
Abstract
Liquid-burning combustion chambers have a wide range of applications in propulsion systems and energy conversion processes. The growing need for reliable and low-NOx combustion systems highlights the role of high-performance burners, where the main design criticalities are related to injectors and swirlers. In the current study, an algorithm for coupling the design procedure of pressure-swirl injectors and axial swirlers is introduced. Also, this algorithm emphasizes the interrelation between the design parameters of these two components via employing the length of the recirculation zone as the coupling parameter for building a relationship between the design characteristics of the injector...
Extended two-dimensional PCA for efficient face representation and recognition
, Article 2008 IEEE 4th International Conference on Intelligent Computer Communication and Processing, ICCP 2008, Cluj-Napoca, 28 August 2008 through 30 August 2008 ; October , 2008 , Pages 295-298 ; 9781424426737 (ISBN) ; Manzuri Shalmani, M. T ; Khademi, M ; Sharif University of Technology
2008
Abstract
In this paper a novel method called Extended Two-Dimensional PCA (E2DPCA) is proposed which is an extension to the original 2DPCA. We state that the covariance matrix of 2DPCA is equivalent to the average of the main diagonal of the covariance matrix of PCA. This implies that 2DPCA eliminates some covariance information that can be useful for recognition. E2DPCA instead of just using the main diagonal considers a radius of r diagonals around it and expands the averaging so as to include the covariance information within those diagonals. The parameter r unifies PCA and 2DPCA. r=1 produces the covariance of 2DPCA, r=n that of PCA. Hence, by controlling r it is possible to control the...
Catalytic conversion of bio-renewable glycerol to pure hydrogen and syngas: Energy management and mitigation of environmental pollution
, Article Energy Conversion and Management ; Volume 247 , 2021 ; 01968904 (ISSN) ; Lotfi Varnoosfaderani, M ; Moghadasin, M. H ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Hydrogen and syngas, as two effective clean fuels, have a considerable stake in the global fuel market. These are dominantly produced from fossil fuels through reforming processes, which lose a large amount of energy and emit numerous amounts of CO2. Bio-renewable glycerol steam reforming is an attractive alternative to traditional reforming for reducing the dependence on hydrocarbon resources and mitigating climate change. This research aims to manage a heat-integrated reactor with three concentric cylinders, containing exothermic-side (methane tri-reforming), endothermic-side (glycerol steam reforming), and permeation-side for co-production of pure hydrogen and syngas. In this process,...