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shahmoradi--mohammad-reza
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Control of Hybrid Systems Using Tube-based MPC
, M.Sc. Thesis Sharif University of Technology ; Haeri, Mohammad (Supervisor)
Abstract
The focus of this thesis is on robust control of hybrid systems using tube-based model predictive control. Hybrid systems are systems that contain both continuous and discrete components. The hybrid nature of these systems can stem from inherent switching behavior that occurs in many dynamical or digitally controlled systems, or from approximation of nonlinear systems. The ability of these systems to model a vast amount of physical phenomena has been attracted a lot of attention from control society. Although much effort have been made on the control of “nominal” hybrid systems, robust stabilization of these systems still seems to be immature. One of the most successful approaches toward...
Pricing of Infrastructure as a Service in Cloud Computing
, M.Sc. Thesis Sharif University of Technology ; Sedghi, Nafiseh (Supervisor)
Abstract
The growing demand for scalable and cost-effective computing resources has led to the widespread adoption of the Infrastructure as a Service (IaaS) model in cloud computing. One of the pricing models for resources, or virtual machines, in this service is the Spot model, which allows customers to access unused cloud server capacity at significantly lower costs compared to other models. However, despite their affordability, these virtual machines do not come with a Service Level Agreement (SLA) and may experience interruptions during use. Such interruptions increase the time required for customers to complete their tasks. In this study, we utilize discrete-event system simulations to examine...
Antibiotic Delivery System for Dental Pulp
, M.Sc. Thesis Sharif University of Technology ; Abdekhodaie, Mohammad Jafari (Supervisor) ; Nekoofar, Mohammad Hossein (Supervisor)
Abstract
A triple antibiotic mixture (ciprofloxacin, metronidazole, and minocycline) has been used for dental root canal medicaments in pulp regeneration therapy. However, tooth discolorations, cervical root fractures, and inadequate pulp-dentin formation have been reported due to the triple antibiotic regimen. Therefore, antibiotic containing scaffold has been developed to minimize the clinical limitations and maximize a natural healing process in root canal infections. The ideal controlled release drug device should have the following characteristics. It should not degrade inside the root canal and it should be easily inserted into and removed from the root canal. In addition, the drug should be...
Study of Viscoelastic Properties of Biopolymer Solutions
, M.Sc. Thesis Sharif University of Technology ; Seyed Reihani, Nader (Supervisor)
Abstract
Properties of viscoelastic of biopolymers have important role in cells structure; for example: cell motility depends on viscoelastic propertie of Actin polymer. therefore according to its importance ,in this thesis we intend to examine the viscoelastic modulus using Optical tweezers and dissipation theorem.this method is benefits than methods of active microrheology. for example this method can be used for low concentrations; because in the low concentrations, the exerting force will cause changing in the state of matter that here we investigate destructive force effect. we investigate viscoelastic of water for method accuracy then obtain viscoelastic of Kelcogel
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...
A fuzzy sequential locomotion mode recognition system for lower limb prosthesis control
, Article 2017 25th Iranian Conference on Electrical Engineering, ICEE 2017, 2 May 2017 through 4 May 2017 ; 2017 , Pages 2153-2158 ; 9781509059638 (ISBN) ; Bagheri Shouraki, S ; Sharif University of Technology
2017
Abstract
Control of powered lower limb prostheses has a locomotion mode-dependent structure which demands a pattern recognizer that can classify the current locomotion mode and also detect transitions between them in an appropriate time. In order to achieve this goal, this paper presents a Fuzzy sequential locomotion mode recognition system to classify daily locomotion modes including level- walking, stair climbing, slope walking, standing and sitting using low-cost mechanical sensors. Since these signals have a quasi-periodic nature, using sequential pattern recognition tools, such as Hidden Markov Model(HMM) improves the recognition performance considering they use sequences of information to make...
Evaluation of a novel fuzzy sequential pattern recognition tool (fuzzy elastic matching machine) and its applications in speech and handwriting recognition
, Article Applied Soft Computing Journal ; Volume 62 , January , 2018 , Pages 315-327 ; 15684946 (ISSN) ; Bagheri Shouraki, S ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
Sequential pattern recognition has long been an important topic of soft computing research with a wide area of applications including speech and handwriting recognition. In this paper, the performance of a novel fuzzy sequential pattern recognition tool named “Fuzzy Elastic Matching Machine” has been investigated. This tool overcomes the shortcomings of the HMM including its inflexible mathematical structure and inconsistent mathematical assumptions with imprecise input data. To do so, “Fuzzy Elastic Pattern” was introduced as the basic element of FEMM. It models the elasticity property of input data using fuzzy vectors. A sequential pattern such as a word in speech or a piece of writing is...
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...
Fatigue status recognition in a post-stroke rehabilitation exercise with sEMG signal
, Article 2017 24th Iranian Conference on Biomedical Engineering and 2017 2nd International Iranian Conference on Biomedical Engineering, ICBME 2017, 30 November 2017 through 1 December 2017 ; 2018 ; 9781538636091 (ISBN) ; Zare, A ; Behzadipour, S ; Sharif University of Technology
2018
Abstract
Exercise therapy is considered as one of the main rehabilitation treatments for post-stroke patients, especially by utilizing modern technologies, such as virtual and/or augmented reality. However, in order to design an appropriate exercise program, which prolongs the exercise duration and maximize the patient's improvement, the fatigue status needs to be detected and used for the program adjustment. In the previous fatigue recognition works, only exercises for healthy and athlete subjects have been taken into account. In this paper, fatigue status classification has been accomplished in a rehabilitation exercise for poststroke patients. To do so, the reaching task, as a basic rehabilitation...
Design and Implementatioan of a Locomotion mode Recognition Algorithm for Powered Lower-Limb Prosthesis
, M.Sc. Thesis Sharif University of Technology ; Bagheri Shouraki, Saeed (Supervisor)
Abstract
Control of powered lower limb prostheses has a locomotion mode- ependent structure which demands a pattern recognizer that can classify the current locomotion mode and also detect transitions between them in an appropriate time. In the way to achieve this goal, this project presents a locomotion mode recognition system to classify daily locomotion modes consist of level- walking, stair climbing, slope walking, standing and sitting using low-cost mechanical sensors. Since these signals have a quasi-periodic nature, using sequential pattern recognition tools, such as Hidden Markov Model(HMM) improves the recognition performance,because they use sequences of information to make a decision. On...
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)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...
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...
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 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...
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...