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    An efficient simulated annealing approach to the traveling tournament problem [electronic resource]

    , Article American Journal of Operations Research ; Vol.2 No.3, September 2012, 391-398 Nourollahi, S (Sevnaz) ; Eshghi, Kourosh ; Shokri Razaghi, Hooshmand ; Sharif University of Technology
    Abstract
    Scheduling sports leagues has drawn significant attention to itself in recent years, as it involves considerable revenue as well as challenging combinatorial optimization problems. A particular class of these problems is the Traveling Tournament Problem (TTP) which focuses on minimizing the total traveling distance for teams. In this paper, an efficient simulated annealing approach is presented for TTP which applies two simultaneous and disparate models for the problem in order to search the solutions space more effectively. Also, a computationally efficient modified greedy scheme is proposed for constructing a favorable initial solution for the simulated annealing algorithm. Our... 

    Transportation and Settling Distribution of Microparticles in Low-Reynolds-Number Poiseuille Flow in Microchannel

    , Article Journal of Dispersion Science and Technology ; Volume 37, Issue 4 , 2016 , Pages 582-594 ; 01932691 (ISSN) Razaghi, R ; Saidi, M. H ; Sharif University of Technology
    Taylor and Francis Inc  2016
    Abstract
    In this article, velocity field and settling distribution of microparticles in a dilute suspension in low-Reynolds-number Poiseuille flow in a microchannel is experimentally investigated using microscopic image analysis. An effective technique is applied to manipulate single-particle tracking in order to determine the controlling parameters on transportation and settling of microparticles in microchannels. The results show that the velocities of dispersed phase are affected by the hydrodynamic properties, and this velocity deviation can be significant when the hydrodynamic coupling between particles and channel walls is considerable. Increasing the Reynolds number would result in decrease in... 

    Experimental investigation of drag and lift forces on microparticles in low reynolds number poiseuille flow in microchannel

    , Article Journal of Dispersion Science and Technology ; Volume 37, Issue 12 , 2016 , Pages 1767-1777 ; 01932691 (ISSN) Razaghi, R ; Saidi, M. H ; Sharif University of Technology
    Taylor and Francis Inc  2016
    Abstract
    In this paper, the hydrodynamic drag and lift forces on microparticles in a dilute suspension in low Reynolds number Poiseuille flow in a microchannel is experimentally investigated using microscopic image analysis. An effective technique is applied to manipulate single-particle tracking in order to determine the velocity field and hydrodynamic forces on microparticles with diameter-to-channel height ratio of 0.1 (Formula presented.) in microchannels. The results show that there is a distance near the walls of the channel in which the hydrodynamic coupling between the particles and channel walls is considerable. Also, the magnitude of drag force that is imposed on the particles with... 

    A novel time-frequency receiver for unknown fast fading channels

    , Article 2004 IEEE Wireless Communications and Networking Conference, WCNC 2004, Atlanta, GA, 21 March 2004 through 25 March 2004 ; Volume 3 , 2004 , Pages 1572-1577 ; 0780383443 (ISBN) Razaghi, P ; Khalaj, B. H ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2004
    Abstract
    A new approach for data detection in fast fading channels is proposed. By using a combination of Rake receiver and sequential detection for fast fading channels, it is shown that system performance can be improved without prior knowledge of the channel. As will be shown in this paper, by combining spread spectrum signaling and sequential detection it is possible to exploit the time-frequency diversity of fast fading channels in a novel way. It is shown by simulation that combination of sequential detection and Rake receiver can effectively improve system performance, compared with equal gain combining  

    Linear decoupled and quasi-decoupled space-time codes

    , Article IEEE Transactions on Communications ; Volume 55, Issue 1 , 2007 , Pages 54-59 ; 00906778 (ISSN) Razaghi, P ; Khalaj, B. H ; Shamsi, M ; Sharif University of Technology
    2007
    Abstract
    Space-time transmit diversity results in coupling of transmitted symbols across different antennas, which increases the complexity of maximum-likelihood decoding. Symbol coupling can be completely or partially avoided if the space-time code (STC) satisfies specific decoupling conditions; examples of such codes are orthogonal space-time block codes and quasi-orthogonal codes. In this letter, we study decoupling conditions for a linear full-diversity STC. Quasi-decoupled codes are proposed as a partially decoupled full-diversity STC of any rate for any number of transmit antennas with minimum decoding delay. By optimizing the coding gain of quasi-decoupled codes, it is shown that... 

    Laboratory-Scale Investigation of Rock Mechanical Behavior under Reservoir Condition

    , M.Sc. Thesis Sharif University of Technology Razaghi, Negar (Author) ; Shad, Saeed (Supervisor) ; Pak, Ali (Co-Supervisor)
    Abstract
    Geomechanics has an immense impact on petroleum engineering and applies to the most aspects of petroleum extraction, from exploration and drilling to production and even reservoir abandonment. Studying the mechanical behavior of rocks in hydrocarbon reservoirs and overburden layers will lead to better characterization of mechanical state of the environment. Therefore, a solid understanding of rock mechanical behavior can play a crucial role in reducing operational issues of oil and gas extraction in different phases and prevent extra cost and time consumption. To illustrate, studies of wellbore stability and integrity, casing burst and collapse, drilling optimization, sand production,... 

    Coupled hydro-mechanical analysis of underground gas storage at Sarajeh field, Qom formation, Iran

    , Article Journal of Natural Gas Science and Engineering ; Volume 92 , 2021 ; 18755100 (ISSN) Bakhtiari, M ; Shad, S ; Zivar, D ; Razaghi, N ; Sharif University of Technology
    Elsevier B.V  2021
    Abstract
    Production or injection of fluids from/in an underground storage site causes variations of pore pressure and stress states. These fluctuations significantly affect implications for hydraulic fracturing, wellbore integrity, top surface subsidence and heave, fault-reactivation, and stability of reservoir and caprock. Therefore, in order to keep optimal conditions during the process of gas injection and production, it is of paramount importance to have accurate estimates of the pore pressure. In this investigation, coupled fluid flow and geomechanical simulations, as well as rock mechanical tests, are performed on the Sarajeh field, Iran to investigate the geomechanical behavior of the Sarajeh... 

    CytoGTA: a cytoscape plugin for identifying discriminative subnetwork markers using a game theoretic approach

    , Article PLoS ONE ; Volume 12, Issue 10 , 2017 ; 19326203 (ISSN) Farahmand, S ; Foroughmand Araabi, M. H ; Goliaei, S ; Razaghi Moghadam, Z ; Sharif University of Technology
    2017
    Abstract
    In recent years, analyzing genome-wide expression profiles to find genetic markers has received much attention as a challenging field of research aiming at unveiling biological mechanisms behind complex disorders. The identification of reliable and reproducible markers has lately been achieved by integrating genome-scale functional relationships and transcriptome datasets, and a number of algorithms have been developed to support this strategy. In this paper, we present a promising and easily applicable tool to accomplish this goal, namely CytoGTA, which is a Cytoscape plug-in that relies on an optimistic game theoretic approach (GTA) for identifying subnetwork markers. Given transcriptomic...