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A Framework for Identification of Dynamic Capabilities
, M.Sc. Thesis Sharif University of Technology ; Mashayekhi, Alinaghi (Supervisor) ; Arasti, Mohammad Reza (Co-Advisor)
Abstract
The strategic importance of Dynamic Capability (DC) has been a central theme in Strategic Management literature since Teece article released in 1997. But, relatively little attention has been given to the operationalization of the concept in organizations. In this paper we propose a framework based on Pavlo and Daneel researches to identify DC in an organization. Through a in-depth case study in dairy industry we explore the detail component of our framework. With a series of interviews with managers and experts of an Iranian dairy producing company, we first confirmed the framework as a whole and then we conclude that the process of DC introduced by Pavlo can have different interpretation...
Generation of Endurance Time Functions Compatible with Near-Field Ground Motions
, M.Sc. Thesis Sharif University of Technology ; Esmail Pourestekanchi, Homayoon (Supervisor) ; Mashayekhi, Mohammad Reza (Co-Supervisor)
Abstract
In the last few decades, the severe damages caused by near-field earthquakes have made researchers to investigate and study more of these types of earthquakes. The effect of forward directivity, which causes pulses with strong amplitude and long period in the velocity time history, is the main cause of severe damages of these types of earthquakes. The endurance time method is a dynamic analysis method in which the structure is subjected to increasing excitation functions. The purpose of this research is to investigate the effects of near-field earthquakes on structures and also to determine the accuracy of estimating responses caused by near-field earthquakes by the existing endurance time...
Measuring the Extent of Usage of Different Levers of Control in Three Iranian Companies with Different Value Creation Logics
, M.Sc. Thesis Sharif University of Technology ; Mashayekhi, Alinaghi (Supervisor)
Abstract
The purpose of this research has been measuring how much studied companies use different levers of controls. Management control system has been described as the system which ensures the organization about implementing its strategy (Antony, 2004; Simons, 1995). In this research we chose Levers of Control framework (Simons, 1995) as the proper model to describe management control systems in organizations. Using related literatures, we developed a questionnaire to measure how much different organizations use each levers of control. The proposed questionnaire was distributed in three businesses with different Value Creation Logics (Stabell & Fjeldstad, 1998), to provide a ...
A misbehavior‐tolerant multipath routing protocol for wireless Ad hoc networks [electronic resource]
, Article International Journal of Research in Wireless Systems (IJRWS) ; Vol. 2, Issue 9, pp. , Sep. 2013 ; Pakravan, Mohammad Reza ; Aref, Mohammad Reza ; Sharif University of Technology
Abstract
Secure routing is a major key to service maintenance in ad hoc networks. Ad hoc nature exposes the network to several types of node misbehavior or attacks. As a result of the resource limitations in such networks nodes may have a tendency to behave selfishly. Selfish behavior can have drastic impacts on network performance. We have proposed a Misbehavior-Tolerant Multipath Routing protocol (MTMR) which detects and punishes all types of misbehavior such as selfish behavior, wormhole, sinkhole and grey-hole attacks. The protocol utilizes a proactive approach to enforce cooperation. In addition, it uses a novel data redirection method to mitigate the impact of node misbehavior on network...
Investigation of the Influence of Strong-Motion Duration on Endurance Time Analysis
, M.Sc. Thesis Sharif University of Technology ; Esmaeil Pourestekanchi, Homayoon (Supervisor)
Abstract
Endurance Time Method (ET) is a dynamic analysis in which structures are subjected to intensifying accelerograms and performance of them are assessed based on their response at different excitation levels. Duration consistency of current ET accelerograms has not been directly considered. Strong motion duration can strongly influence the response of structures and foundations especially when they encounter degrading characteristics in their materials. In this study, duration related properties of ET accelerograms and ground motions are compared. These properties consist of strong motion duration, cycles number of motion and number of nonlinear cycles which a structure should sustain when it...
Analyzing Mechanisms Which Create Instability in Attention to Care vs. Health in National Health System and Their Effects
, M.Sc. Thesis Sharif University of Technology ; Mashayekhi, Alinaghi (Supervisor) ; Malaek, Mohammad Bagher (Co-Advisor)
Abstract
Each National Health System has to choose a combination of health and treatment programs, as the health policy to keep people healthy. As a result of shared resources, the more concentration on treatment, make health program weaker and so thegreater rate of prevalence of diseases and the more burden on treatment programs. At this situation, the problem of lack of ability to pay for health services and products will seriously threaten the health of society. Based on statistics of health status, Iran is going to face this state. So here at this thesis, in order to simulate and study the behaviors of key state variables during the time, the model of national health system developed by system...
Analysis and Improvement of Intrusion Detection Methods in Data Network Routers
, M.Sc. Thesis Sharif University of Technology ; Aref, Mohammad Reza (Supervisor) ; Pakravan, Mohammad Reza (Co-Advisor)
Abstract
High-quality online services demand reliable and fast packet delivery at the network layer. However, clear evidence documents the existence of compromised routers in the ISP and enterprise networks, threatening network availability and reliability. A compromised router can stealthily drop, modify, inject, or delay packets in the forwarding path to launch Denial-of-Service, surveillance, man-in-the-middle attacks, etc. So researches tried to create intrusion detection methods to identify adversarial routers and switches. To this end, data-plane fault localization (FL) aims to identify faulty links and is an effective means of achieving high network availability. FL protocols use...
Topological Defects in Confined Nematics by Planar Anchoring
, M.Sc. Thesis Sharif University of Technology ; Ejtehadi, Mohammad Reza (Supervisor) ; Mozaffari, Mohammad Reza (Supervisor)
Abstract
Confining nematic liquid crystal between two curved boundary conditions while the nematic molecules have a degenerate planar anchoring leads to complex and beautiful textures of molecular disparagement(defect) in the bulk and on the surfaces. Such the liquid crystal shells are made with double-emulsion techniques in microfluidic devices have provided applications for micro-scale colloidal linkers.In this work, we have numerically minimized the elastic energy in one-constant approximation in present of Fournier’s degenerate surface potential with finite element method. The nematic shell is confined between two spherical surfaces that we have studied the final energies and their related...
Improvement of Routing Security in Ad Hoc Networks Against Several Attacks
, M.Sc. Thesis Sharif University of Technology ; Aref, Mohammad Reza (Supervisor) ; Pakravan, Mohammad Reza (Supervisor)
Abstract
Secure routing is a major key to service maintenance in wireless ad hoc networks. Ad hoc nature exposes the network to several types of node misbehavior or attacks. Wormhole attack is one of the most severe active attacks to mobile ad hoc networks. Noting the resource limitations in such networks, nodes may have a tendency to behave selfishly. Selfish behavior can have drastic impacts on network performance. We have proposed a Misbehavior-Tolerant Multipath Routing protocol (MTMR) which detects and punishes all types of misbehavior such as selfish behavior, wormhole, sinkhole and grey-hole attacks. The protocol utilizes a proactive approach to enforce cooperation. In addition, it uses a...
Solving Symmetric Nonlinear Equations System Using BFGS Trust Region Quadratic Method
, M.Sc. Thesis Sharif University of Technology ; Razvan, Mohammad Reza (Supervisor) ; Peyghami, Mohammad Reza (Supervisor)Design and Implementation of 2.5 Gbps Circuit Switching Fabric
, M.Sc. Thesis Sharif University of Technology ; Pakravan, Mohammad Reza (Supervisor) ; Movahhedy, Mohammad Reza (Supervisor)
Abstract
Providing high bandwidth network infrastructures for ever increasing need of data transport is of great importance. The underling infrastructure for many communication services such as GSM/3G/4G mobile networks and Internet services is Synchronous Digital Hierarchy (SDH) optical transport systems. SDH are standardized protocols that multiplex multiple lower rate digital bit streams, such as E1 and Ethernet, and transfer them synchronously over optical fiber using lasers or LEDs. In addition to high data transfer rates, flexible network management and protection mechanisms have great importance, hence are part of SDH standards. In order to obtain flexible network architecture and protected...
Preserving Privacy in Smart Grid
, M.Sc. Thesis Sharif University of Technology ; Aref, Mohammad Reza (Supervisor) ; Pakravan, Mohammad Reza (Co-Advisor)
Abstract
Development of Smart Grid and deployment of smart meters in large scale has raised a lot of concerns regarding customers’ privacy. Consequently, several schemes have been proposed to overcome the above mentioned issue. These schemes mainly rely on data aggregation as a method of protecting users’ privacy from the grid operators. However, the main problem with most of these schemes is the fact that they require a large amount of processing power at the meter side. This, together with the fact that smart meters don’t usually have a powerful processor, can cause the unavailability of smart meter data at the required time for operators of the grid, and at the same time disables smart meters from...
Effect of the Geometry of Colloidal Particles on Nematic Liquid Crystals
, Ph.D. Dissertation Sharif University of Technology ; Ejtehadi, Mohammad Reza (Supervisor) ; Mozaffari, Mohammad Reza (Co-Advisor)
Abstract
A liquid crystal is a state of matter composed of highly anisotropic building blocks. When liquid crystals are exposed to surfaces with given shapes and anchoring conditions, the orientation of their molecules gets spatially disordered and topological defects may form in the system. The interplay between liquid crystals and the geometry and topology of the colloidal particles has motivated extensive recent studies.In this thesis, we present the numerical modeling results for two faceted colloidal particles in a thermotropic nematic liquid crystal. To obtain the equilibrium nematic field with a finiteelement method, we numerically minimize the free energy of the system that based on the...
Solving Nonlinear Systems of Mixed Iqualities and Inequalities Via Trust Region Quadratic Methods
, M.Sc. Thesis Sharif University of Technology ; Razvan, Mohammad Reza (Supervisor) ; Payghami, Mohammad Reza (Supervisor)Jamming Resilient Algorithms for Rendezvous in Cognitive Radio Networks
, M.Sc. Thesis Sharif University of Technology ; Aref, Mohammad Reza (Supervisor) ; Pakravan, Mohammad Reza (Co-Advisor)
Abstract
Dynamic spectrum access with the aid of cognitive radio (CR) technology is a viable solution to spectrum scarcity. There are many military and emergency applications that require the use of cognitive radio ad-hoc networks (CRAHNs). In these net- works, nodes must first find each other in a wide spectrum and then exchange their desired data. The process of finding each other in a multichannel environment is a challenging task and is usually known as rendezvous. Since rendezvous is the first step in communication, disrupting will disable the nodes from establishing proper communication sessions. That results in a drastic degrade in the performance of the network. Therefore, it is important to...
Numerical Study of Spray Impingement to Solid Wall
, M.Sc. Thesis Sharif University of Technology ; Morad, Mohammad Reza (Supervisor) ; Jahannama, Mohammad Reza (Co-Supervisor)
Abstract
Spray-wall impingement is one of the phenomenon that associated in different subject such as spray cooling, combustion chamber and gas turbine. With the impingement of spray to the wall, liquid film begins to form. Wall film characteristics is still an important subject to study. Due to the various stages of liquid film formation from injection of spray till spray-wall impingement, the investigation of this phenomenon is far more complicated. This paper is meant to provide detailed data on spray-wall impingement and wall film formation physics with the help of computational analysis of OpenFOAM . A Lagrangian-Eulerian method based on discrete phase model (DPM) was employed to model...
Generation of Endurance Time Excitation Functions using Wavelet Transform and Heuristic Optimization Methods
, Ph.D. Dissertation Sharif University of Technology ; Vafai, Abolhassan (Supervisor) ; Esmaeil Purestekanchi, Homayoon (Supervisor)
Abstract
Endurance Time (ET) method is a dynamic analysis in which structures are subjected to intensifying acceleration time histories. These excitations are also called Endurance Time Excitation Functions (ETEF). The reliability and accuracy of the ET method heavily depends on the accuracy of ETEFs. ETEFs are generated so that ETEFs dynamic characteristics must be consistent with dynamic characteristics of real ground motions. Since the number of ETEFs equations are considerably more than variables noninear optimization is used to generate ETEFs. In order to improve the accuracy of ETEFs two approaches can be used. First, modifying the objective function equations by considering more dynamic...
Factors influencing adoption of e-payment systems: an empirical study on Iranian customers
, Article Information Systems and e-Business Management ; Volume 15, Issue 1 , 2017 , Pages 89-116 ; 16179846 (ISSN) ; Nourollah, Z ; Mashayekhi, H ; Mashayekhi, Y ; Ahangar, M. S ; Sharif University of Technology
Springer Verlag
2017
Abstract
Internet technology has influenced the banking systems because of its capability to enhance performance of financial operations. A major concern of Internet banking systems is the customers’ perception of security and trust. This study presents an experimental investigation on important factors influencing trust in e-payments systems in Iran. A set of potentially determinant factors of trust is developed and organized in three major groups: technical and transaction procedures, access to security guidelines, and usability. The direct effect of the factors on perceived trust, along with their indirect effect through perceived security, is evaluated in an empirical study. The data are...
Assessing and Improving Algorithms to Control the Propagation of Light through Scattering Media
, M.Sc. Thesis Sharif University of Technology ; Rahimitabar, Mohammad Reza (Supervisor) ; Nasiriavanaki, Mohammad Reza (Supervisor)
Abstract
Light propagation through turbid media, such as biological tissues, experience scattering due to inhomogeneous distribution of refractive indices of their microscopic structure. Scattering and diffusion of light not only limit many optical imaging techniques, but are also big challenges for telecommunication, spectroscopy, and other optical techniques. Recently many new imaging methods are developed that work in strongly scattering media such as optical coherence tomography, diffusion tomography, and laser speckle velocimetry. In this thesis, we have studied how wavefront shaping techniques can tackle the problem of scattering. By spatially shaping the wavefront of the incident beam, using...
Investigations on the Effect of Biosurfactants on the Wettability of Carbonate Rocks via Interactions with Rock and Fluid in Ex-Sito MEOR
, Ph.D. Dissertation Sharif University of Technology ; Roosta Azad, Reza (Supervisor) ; Kamali, Mohammad Reza (Supervisor) ; Shadizadeh, Reza (Co-Advisor)
Abstract
The effects of biosurfactants on sandstone rocks are known in the literature. However, there are few examples of experimental works in Iranian carbonate reservoirs dealing with the effects of biosurfactants under reservoir conditions. This thesis discusses the effect of an efficient biosurfactant produced from Pseudomonas aeroginosa MRo1, a bacterial strain isolated from oil excavation areas in southern Iran, on the recovery of residual oil trapped within carbonate rocks was investigated. The MRO1 could reduce surface tension from 72 to 28 dyne/cm. It also could reduce Interfacial tension from 18.382 to 5.646 dyne/cm.
In a core holder set-up bearing four limestone- and...
In a core holder set-up bearing four limestone- and...