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    Quantum Walk Application in Search Algorithms

    , M.Sc. Thesis Sharif University of Technology Ghorban Fekr, Hossein (Author) ; Karimipour, Vahid (Supervisor)
    Abstract
    Providing an Algorithm whi? can solve the sear? problem using minimum resources(su? as time, memory and so on)has been ?allenged by computer science experts for many years. By discovering the quantum computer it can be asked that does the quantum algorithm provide a be?er solution to sear? problem? ?e answer is yes. In this thesis the grover’s algorithm, the quantum sear? algorithm using the quantum walk, probabilistic quantum sear? algorithm and finally the two-qubit grover sear? algorithm implementation in physical world will be discussed  

    Investigation of the Effect of Interleaved Memory on WCET in Real-Time Embedded System

    , M.Sc. Thesis Sharif University of Technology Hossein Ghorban, Ali (Author) ; Ejlali, Alireza (Supervisor)
    Abstract
    Worst case execution time (WCET) and energy consumption are two of the most important design constraints of real-time embedded systems and memory subsystem has a major impact on both of them. Therefore, many recent studies have tried to improve the memory subsystem of embedded systems by using emerging non-volatile memories instead of conventional memories such as SRAM and DRAM. Indeed, the low leakage power dissipation and improved density of emerging non-volatile memories, makes them prime candidates for replacing the conventional memories. However, accessing these memories imposes performance and energy overhead and using them as the code memory may increase the WCET.Furthermore, most... 

    A rewiring mechanism to improve synchronization in Kuramoto networks

    , Article Journal of Statistical Mechanics: Theory and Experiment ; Volume 2022, Issue 11 , 2022 ; 17425468 (ISSN) Hossein Ghorban, S ; Hesaam, B ; Sarbazi Azad, H ; Sharif University of Technology
    Institute of Physics  2022
    Abstract
    The emergence of synchronization among a set of individual oscillators that are coupled in a network is an amazing physical phenomenon that appears in many different systems, from natural sciences to even human behavior. The phenomenon has attracted the attention of many researchers in many fields of science and engineering by the science behind its unique collective behavior without some kind of external organization. One of the most popular models for the dynamical evolution of coupled phase oscillators is the Kuramoto model, which gives a simple yet powerful formalization together with a numerical measure called the degree of synchronization. The crucial role of structural properties of... 

    Dominating coloring number of claw-free graphs

    , Article Electronic Notes in Discrete Mathematics ; Vol. 45, issue , January , 2014 , pp. 91-97 ; ISSN: 15710653 Abdolghafurian, A ; Akbari, S ; Hossein Ghorban, S ; Qajar, S ; Sharif University of Technology
    2014
    Abstract
    Let G be a graph. It is well-known that G contains a proper vertex-coloring with χ(G) colors with the property that at least one color class of the coloring is a dominating set in G. Among all such proper vertex-coloring of the vertices of G, a coloring with the maximum number of color classes that are dominating sets in G is called a dominating-χ-coloring of G. The number of color classes that are dominating sets in a dominating-χ-coloring of G is defined to be the dominating-χ-color number of G and is denoted by dχ(G). In this paper, we prove that if G is a claw-free graph with minimum degree at least two, then dχ(G)≥2  

    Linearization error in synchronization of Kuramoto oscillators

    , Article Applied Mathematics and Computation ; Volume 411 , December , 2021 ; 00963003 (ISSN) Hossein Ghorban, S ; Baharifard, F ; Hesaam, B ; Zarei, M ; Sarbazi Azad, H ; Sharif University of Technology
    Elsevier Inc  2021
    Abstract
    Synchronization among a set of networked nodes has attracted much attention in different fields. This paper thoroughly investigates linear formulation of the Kuramoto model, with and without frustration, for an arbitrarily weighted undirected network where all nodes may have different intrinsic frequencies. We develop a mathematical framework to estimate errors of the linear approximation for globally and locally coupled networks. We mathematically prove that the eigenvector corresponding to the largest eigenvalue of the network's Laplacian matrix is enough for examining synchrony alignment and that the functionality of this vector depends on the corresponding eigenvalue. Moreover, we prove... 

    Modeling and Simulation of Vacuum Assisted Resin Transfer Molding Process with Flexible Tooling

    , M.Sc. Thesis Sharif University of Technology Ghorban Nia Hassankiadeh, Arash (Author) ; Abedian, Ali (Supervisor)
    Abstract
    Resin Transfer Molding (RTM) which is one of the categories of Liquid Composite Molding (LCM) process, is considered as one of the most important process in polymer composite manufacturing. To improve this manufacturing method and reaching higher qualities, numerous modified methods has been developed. One of these modified methods is Vaccum Assisted Resin Trasnfer Molding with Flexible Tooling which is considerably applicable in manufacturing parts with high quality, large and complex geometry. Although, this manufacturing method has variety of advantages, there are some problems such as void formation making production difficult and dependent to experimental trial and error. So numerical... 

    Experimental Study of the Performance of Fuel System of Single-Tube Pulse Detonation Engine

    , M.Sc. Thesis Sharif University of Technology Ghorban Hosseini, Mostafa (Author) ; Farshchi, Mohammad (Supervisor) ; Durali, Mohammad (Co-Advisor)
    Abstract
    Fuel system is one of the most important parts of pulse detonation engine which has the responsibility of fuel, oxidizer and also purge gas in the different operational frequencies of engine. Although pulse detonation engines are sort of air breathing engines and purge gas and oxidizer one in the same unit in their structure, due to existence idea in the pulse detonation rocket engines coverage of functional condition, fuel, oxidizer and purge gas, will study it in three different structures.
    In this study purpose is improvement of the pulse detonation engine of Sharif University which will provide as the possibility of safe functional condition and high operational frequency in... 

    Quantitative Assessment of Parkinson Patient’s Health Improvement Using Kinect for Telerehabilitation

    , M.Sc. Thesis Sharif University of Technology Alavian, Mostafa (Author) ; Behzadipour, Saeed (Supervisor) ; Taghizade, Ghorban (Co-Supervisor)
    Abstract
    Parkinson's disease is the most common progressive neurological disorder after Alzheimer, which is associated with motor disabilities. One of the most effective ways to improve patient’s condition with this disease, is rehabilitation.Assessment of the patient during rehabilitation is very important in order to give a better understanding of patient's status to the specialist, but qualitative assessment methods in traditional rehabilitation are ineffective in fast and accurate evaluation of the patient's condition; and because of their need for patient’s attendance in clinic, they will incur huge medical costs. Therefore, the purpose of the present study is to present a quantitative method to... 

    Balance Assessment in Parkinson Disease based on a Combination of Posturographic Indices

    , M.Sc. Thesis Sharif University of Technology Zahedi, Amir (Author) ; Behzadipour, Saeed (Supervisor) ; Taghizadeh, Ghorban (Supervisor)
    Abstract
    Parkinson's disease is a progressive neurodegenerative disease in which balance disorders are a common symptom. Clinical and non-clinical methods have been developed to evaluate the quality of maintaining balance. Clinical methods include questionnaires and tests that are scored by the therapist and therefore depend on the examiner's skill. On the other hand, there are biomechanical methods that do not depend on the therapist's skill. Posturography -based methods are among the biomechanical tests used today to assess balance. In these methods, some indicators are extracted from the patient's foot center of pressure that can measure the quality of balance. These studies usually examine the... 

    Classification of Pd Patients Based on the Quality of the Upper Extremity Movements Using a Combination of the Kinematic Indices

    , M.Sc. Thesis Sharif University of Technology Abouei Mehrizi, Mojtaba (Author) ; Behzadipour, Saeed (Supervisor) ; Taghizadeh, Ghorban (Supervisor)
    Abstract
    Parkinson's disease, after Alzheimer's, is the most important and common progressive neurodegenerative disorders. There are various methods for assessing the quality of patients’ movements. One of them is biomechanical methods. The application of these methods in telerehabilitation has been considered by many researchers. Telerehabilitation improves the efficiency of the therapists and reduces problems such as commute costs, traffic stress, and patient fatigue.In the present study, 21 Parkinson patients were treated and evaluated remotely using SANA system. This study aimed to investigate the effects of the therapist absence during the tele-assessment and its impact on the validity and... 

    The Development of a Postural Control Model for People with Parkinson’s disease to Predict Rehabilitation Exercises Effects

    , Ph.D. Dissertation Sharif University of Technology Rahmati, Zahra (Author) ; Behzadipour, Saeed (Supervisor) ; Firoozbakhsh, Keikhosrow (Supervisor) ; Taghizadeh, Ghorban (Co-Supervisor)
    Abstract
    Background: Parkinson’s disease (PD) patients seriously suffer from instability and impaired postural control. Rehabilitation exercises help them to recover their ability through long-term practical sessions. For designing optimal tasks in each session, and in agreement with each patient’s state, it is essential to employ computational models and approaches.Objective: The goal of this study is to develop a computational postural control model of Parkinson’s disease in order to provide new understanding of the postural control in PD, and to gain insight on the effect of balance trainings on PD (the learning dynamics), from the view of this model.Methods: In the first phase of this study, the... 

    Calculation of the Energy Release Rate of Nano-Cracks in FCC Materials Via the Many Body Atomic Scale FEM

    , M.Sc. Thesis Sharif University of Technology Ostad Hossein, Alireza (Author) ; Mohammadi Shodja, Hossein (Supervisor)
    Abstract
    Since the classical continuum theory fails to deal with the problems associated with defects, stress concentrators, and relevant deformation phenomena in solids, alternative approaches that can detect the atomistic nature of materials' fracture are required. The deficiency of the capture the size effect which yields delusively high values for some components of the stress field right on the edge of the stress concentrators, and its weakness in describing the complex interaction between small inhomogeneities, cracks and the like when they are only a few nanometers apart, are among some of the disadvantages of the classical approach. In recent years, however, atomistic methods are emerging to... 

    Semisolid Stir Joining of As-Cast Silicon-Aluminum Bronze

    , M.Sc. Thesis Sharif University of Technology Ferasat, Keyvan (Author) ; Kokabi, Amir Hossein (Supervisor) ; Ashuri, Hossein (Supervisor)
    Abstract
    Aluminum Bronzes have many applications in marine environments. These alloys suffer from both hot cracking and cold cracking. In order to overcome the hot cracking and cold cracking, Semisolid Stir Joining method and a proper thermal cycle was used respectively. Effects of temperature, stirring rate, and tool type were investigated in Semisolid Stir joining method. In this method, butt joint design was used in order to place specimens, and the specimens were heated up to specific temperatures (920, 925, 930°C). A stirrer (Cylindrical and Grooved tool) with three rotational speeds (800, 1200, 1600 RPM) was introduced into the stir weld seam. Welded specimens were cooled to the 900°C... 

    The Study of Eliminating Gender Gap in Iran Labor Market on Participation Rate of Married Urban Women

    , M.Sc. Thesis Sharif University of Technology Asghari, Fatemeh (Author) ; Rahmati, Mohammad Hossein (Supervisor) ; Joshaghani, Hossein (Supervisor)
    Abstract
    The low female labor force participation rate in the Iranian labor market relative to the global average and even to countries that do not differ significantly from the socio-economic characteristics of our country is one of the important questions of the Iranian labor market. In this study, we seek to answer the question of whether the economic participation rate of married women will increase if the gender gaps in wages, job findings and job losses among women and men are eliminated in the Iranian labor market. To answer this question using household expenditure and income data and labor force data, we show that between the two categories of occupations, in terms of the share of women's... 

    Graph homomorphisms through random walks [electronic resource]

    , Article Journal of Graph Theory ; 2003, Volume 44, Issue 1, pages 15–38 Daneshgar, A. (Amir) ; Hajiabolhassan, Hossein ; Sharif University of Technology
    Abstract
    In this paper we introduce some general necessary conditions for the existence of graph homomorphisms, which hold in both directed and undirected cases. Our method is a combination of Diaconis and Saloff–Coste comparison technique for Markov chains and a generalization of Haemers interlacing theorem. As some applications, we obtain a necessary condition for the spanning subgraph problem, which also provides a generalization of a theorem of Mohar (1992) as a necessary condition for Hamiltonicity. In particular, in the case that the range is a Cayley graph or an edge-transitive graph, we obtain theorems with a corollary about the existence of homomorphisms to cycles. This, specially, provides... 

    Unique list-colourability and the fixing chromatic number of graphs [electronic resource]

    , Article Discrete Applied Mathematics ; Volume 152, Issues 1–3, 1 November 2005, Pages 123–138 Daneshgar, A. (Amir) ; Hajiabolhassan, Hossein ; Sharif University of Technology
    Abstract
    In this paper we introduce a chromatic parameter, called the fixing chromatic number, which is related to unique colourability of graphs, in the sense that it measures how one can embed the given graph G in G∪Kt by adding edges between G and Kt to make the whole graph uniquely t-colourable. We study some basic properties of this parameter as well as its relationships to some other well-known chromatic numbers as the acyclic chromatic number. We compute the fixing chromatic number of some graph products by applying a modified version of the exponential graph construction  

    Circular colouring and algebraic no-homomorphism theorems

    , Article European Journal of Combinatorics ; Volume 28, Issue 6, August 2007, Pages 1843–1853 Daneshgar, A. (Amir) ; Hajiabolhassan, Hossein ; Sharif University of Technology
    Abstract
    In this paper, we apply some new algebraic no-homomorphism theorems in conjunction with some new chromatic parameters to estimate the circular chromatic number of graphs. To show the applicability of the general results, as a couple of examples, we generalize a well known inequality for the fractional chromatic number of graphs and we also show that the circular chromatic number of the graph obtained from the Petersen graph by excluding one vertex is equal to 3. Also, we focus on the Johnson–Holroyd–Stahl conjecture about the circular chromatic number of Kneser graphs and we propose an approach to this conjecture. In this regard, we introduce a new related conjecture on Kneser graphs and we... 

    Density and power graphs in graph homomorphism problem

    , Article Discrete Mathematics ; Volume 308, Issue 17, 6 September 2008, Pages 4027–4030 Daneshgar, A. (Amir) ; Hajiabolhassan, Hossein ; Sharif University of Technology
    Abstract
    We introduce two necessary conditions for the existence of graph homomorphisms based on the concepts of density and power graph. As corollaries, we obtain a lower bound for the fractional chromatic number, and we set forward elementary proofs of the facts that the circular chromatic number of the Petersen graph is equal to three and the fact that the Coxeter graph is a core  

    Temperature dependence study of nonocontact AFM images using molecular dynamics simulations [electronic resource]

    , Article Int. Journal of Modern Physics ; 2012, Vol. 5, pp. 418-432 Nejat Pishkenari, H. (Hossein) ; Meghdar, Ali ; Sharif University of Technology
    Abstract
    The effect of temperature on the noncontact atomic force microscopy (NC-AFM) surface imaging is investigated with the aid of molecular dynamics (MD) analysis based on the Sutton-Chen (SC) interatomic potential. Particular attention is devoted to the tip and sample flexibility at different temperatures. When a gold coated probe is brought close to the Au (001) surface at high temperatures, the tip and surface atoms are pulled together and their distance becomes smaller. The tip and sample atoms displacement varies in the different environment temperatures and this leads to the different interaction forces. Along this line, to study the effect of temperature on the resulting images, we have... 

    Developing an Analytical Model for Predicting the Residual Stresses Induced by Shot Peening with Considering the Effect of Initial Surface Treatment

    , Ph.D. Dissertation Sharif University of Technology Sherafatnia, Khalil (Author) ; Farrahi, Gholam Hossein (Supervisor) ; Mahmoudi, Amir Hossein (Co-Supervisor)
    Abstract
    Shot peening is a cold-working process commonly used in industry to improve the fatigue performance, stress corrosion resistance and surface nano-crystallization of metallic parts. This process extends fatigue life via two mechanisms: Preventing the crack growth due to compressive residual stresses and, preventing the crack initiation because of increased material hardness. These mechanisms are the results of the bombardment of the component's surface with small spherical particles. In this research, an analytical model is developed for estimating the residual stress distribution induced by shot peening process. The modifications of the developed analytical model are related to...