Loading...
Search for: rasti--soroush
0.153 seconds

    BRST quantization of noncommutative gauge theories

    , Article Physical Review D ; Volume 68, Issue 10 , 2003 ; 05562821 (ISSN) Soroush, M ; Sharif University of Technology
    American Physical Society  2003
    Abstract
    In this paper, the Becchi-Rouet-Stora-Tyutin (BRST) symmetry transformation is presented for the noncommutative U(N) gauge theory. The nilpotency of the charge associated with this symmetry is then proved. As a consequence of the spacelike noncommutativity parameter, the Hubert space of physical states is determined by the cohomology space of the BRST operator as in the commutative case. Further, the unitarity of the S-matrix elements projected onto the subspace of the physical states is deduced. © 2003 The American Physical Society  

    BRST quantization of noncommutative gauge theories

    , Article Physical Review D - Particles, Fields, Gravitation and Cosmology ; Volume 67, Issue 10 , 2003 ; 15507998 (ISSN) Soroush, M ; Sharif University of Technology
    2003
    Abstract
    In this paper, the Becchi-Rouet-Stora-Tyutin (BRST) symmetry transformation is presented for the noncommutative [Formula Presented] gauge theory. The nilpotency of the charge associated with this symmetry is then proved. As a consequence of the spacelike noncommutativity parameter, the Hilbert space of physical states is determined by the cohomology space of the BRST operator as in the commutative case. Further, the unitarity of the S-matrix elements projected onto the subspace of the physical states is deduced. © 2003 The American Physical Society  

    Workspace measurement of the surgeon's upper limb during an arthroscopy and three laparoscopy operations using inertial sensor systems

    , Article 2013 E-Health and Bioengineering Conference, EHB 2013 ; 2013 ; 9781479923731 (ISBN) Soroush, A ; Farahmand, F ; Sharif University of Technology
    2013
    Abstract
    The aim of this study was to determine the workspace of surgeon's body for designing more efficient surgical robots in the operation rooms. Five wearable inertial sensors were placed near the wrist and elbow joints and also on the thorax of surgeons to track the orientation of upper limb. Assuming that the lengths of five segments of an upper limb were known, measurements of the inertial sensors were used to determine the position of the wrist and elbow joints via an established kinematic model. subsequently, to assess the workspace of surgeon upper body, raw data were collected in the arthroscopy and laparoscopy operations. Experimental results demonstrated that the workspaces of surgeon's... 

    Effect of capillary tube's shape on capillary rising regime for viscos fluids

    , Article 2017 International Conference on Nanomaterials and Biomaterials, ICNB 2017, 11 December 2017 through 13 December 2017 ; Volume 350, Issue 1 , 2018 ; 17578981 (ISSN) Soroush, F ; Moosavi, A ; Sharif University of Technology
    Institute of Physics Publishing  2018
    Abstract
    When properties of the displacing fluid are considered, the rising profile of the penetrating fluid in a capillary tube deviates from its classical Lucas-Washburn profile. Also, shape of capillary tube can affect the rising profile in different aspects. In this article, effect of capillary tube's shape on the vertical capillary motion in presence of gravity is investigated by considering the properties of the displacing fluid. According to the fact that the differential equation of the capillary rising for a non-simple wall type is very difficult to solve analytically, a finite element simulation model is used for this study. After validation of the simulation model with an experiment that... 

    Unsteady Analysis of a Slinger Combustion Chamber by the Chemical Reactor Network Model

    , M.Sc. Thesis Sharif University of Technology Soroush, Fariborz (Author) ; Farshchi, Mohammad (Supervisor)
    Abstract
    Up to early seventies, Gas turbine combustor design was very time consuming and costly process including trial and errors through test rigs. Over the time analytical-experimental relationships take place as one of the key rules in the design processes. With the increasing power of computer calculations, computational fluid dynamics find its way in the procedure. Obtaining a deeper understanding of flow conditions and geometry inside the chamber, a great reduction in production time and cost of revisions to rigs and samples were achieved. Finding a precise prediction of polluting elements like NOx (less than 10 ppm) after many run hours and enormous computing resources, CFD methods must... 

    Modeling and Simulation of Alcoholic Fermentation of Sugarcane Blackstrap Molasses

    , M.Sc. Thesis Sharif University of Technology Soroush, Mohammad (Author) ; Yaghmaee, Sohila (Supervisor)
    Abstract
    Fed-batch fermentation is a valuable and cost-effective method for bio-based production of various products such as ethanol, which has various applications in various industries.In recent years, bioethanol production has been given special attention in many countries. For this reason, the mathematical modeling of production of these products is very important for their optimal and cost-effective production. Given the transient and dynamic nature of fermentation and its specific complexity, mathematical modeling of fed-batch bioreactors is difficult and complicated. In this research, an unstructured model was used to predict the production of ethanol from blackstrap sugar cane molasses based... 

    Detection of change to SSVEPs using analysis of phase space topological : a novel approach

    , Article Neurophysiology ; Volume 51, Issue 3 , 2019 , Pages 180-190 ; 00902977 (ISSN) Soroush, M. Z ; Maghooli, K ; Pisheh, N. F ; Mohammadi, M ; Soroush, P. Z ; Tahvilian, P ; Sharif University of Technology
    Springer New York LLC  2019
    Abstract
    A novel method based on EEG nonlinear analysis and analysis of steady-state visual evoked potentials (SSVEPs) has been processed. The EEG phase space is reconstructed, and some new geometrical features are extracted. Statistical analysis is carried out based on ANOVA, and most significant features are selected and then fed into a multi-class support vector machine (MSVM). Both offline and online phases are considered to fully address SSVEP detection. In the offline mode, the whole design evaluation, feature selection, and classifier training are performed. In the online scenario, the proposed method is evaluated and the detection rate is reported for both phases. Subject-dependent and... 

    The semi-analytical modeling and simulation of the VAPEX process of ""Kuh-e-Mond"" heavy oil reservoir

    , Article Petroleum Science and Technology ; Vol. 29, issue. 5 , Oct , 2009 , p. 535-548 ; ISSN: 10916466 Rasti, F ; Masihi, M ; Kharrat, R ; Sharif University of Technology
    2009
    Abstract
    The vapor extraction process (or VAPEX) uses vaporized solvents injected into a horizontal well to form a vapor chamber within the reservoir. Vapor dissolves in the oil and enhances the oil production by decreasing the oil viscosity in heavy oil reservoirs. To evaluate the process we conduct a simulation study on an Iranian heavy oil reservoir called Kuh-e-Mond. In addition, a semi-analytical investigation of the VAPEX process has been performed. The idea is to perform VAPEX simulation for a laboratory model and find a methodology to compare the results of the simulator with the semi-analytical Butler's model. In particular, a semi-analytical dimensionless correlation for production rate... 

    The semi-analytical modeling and simulation of the VAPEX process of "Kuh-e-Mond" heavy oil reservoir

    , Article Petroleum Science and Technology ; Volume 29, Issue 5 , 2011 , Pages 535-548 ; 10916466 (ISSN) Rasti, F ; Masihi, M ; Kharrat, R ; Sharif University of Technology
    2011
    Abstract
    The vapor extraction process (or VAPEX) uses vaporized solvents injected into a horizontal well to form a vapor chamber within the reservoir. Vapor dissolves in the oil and enhances the oil production by decreasing the oil viscosity in heavy oil reservoirs. To evaluate the process we conduct a simulation study on an Iranian heavy oil reservoir called Kuh-e-Mond. In addition, a semi-analytical investigation of the VAPEX process has been performed. The idea is to perform VAPEX simulation for a laboratory model and find a methodology to compare the results of the simulator with the semi-analytical Butler's model. In particular, a semi-analytical dimensionless correlation for production rate... 

    Shaping of Laser Pulse for Molecular Dissociation

    , M.Sc. Thesis Sharif University of Technology Rasti, Soroush (Author) ; Saddighi Bonabi, Rasoul (Supervisor)
    Abstract
    In this project, ionization and dissociation of nitrogen, methane and formaldehyde molecules through interaction by intense femto-second lasers have been investigated. The optimum shape of laser pulses for dissociation of methane and formaldehyde molecules for controlling the dissociation paths into desired products are obtained. Based on time dependent density functional theory and quantum optimal control theory, the calculations are carried out in intensities at the range of 1014-1016 Wcm-2 with pulse durations of 4 -20fs. Octopus package is used as a powerful computational program. By using, quantum optimal control theory, optimum laser pulses with manipulation of amplitude, phase and... 

    Optimal control of dissociation of nitrogen molecule with intense ultra-short laser pulse shaping

    , Article Journal of Molecular Structure ; Volume 1083 , March , 2015 , Pages 121-126 ; 00222860 (ISSN) Rasti, S ; Irani, E ; Sadighi Bonabi, R ; Sharif University of Technology
    Elsevier  2015
    Abstract
    (GraphPresented) The quantum optimal control theory in conjunction with time dependent density functional theory is used to optimize the laser pulse shape for dissociation of nitrogen molecule. For several initial peak intensities and frequency ranges, the optimum shapes are produced and compared to determine the most efficient pulse. Ehrenfest molecular dynamics model is also used to test the dissociation process. The corresponding snapshots of density and time dependent electron localization function are presented. It is noticed that when the frequency ranges of laser pulses are doubled, it leads to 60% faster dissociation of N2 molecule  

    Efficient photo-dissociation of CH4 and H2CO molecules with optimized ultra-short laser pulses

    , Article AIP Advances ; Volume 5, Issue 11 , 2015 ; 21583226 (ISSN) Rasti, S ; Irani, E ; Sadighi Bonabi, R ; Sharif University of Technology
    American Institute of Physics Inc  2015
    Abstract
    The fragmentation dynamics of CH4 and H2CO molecules have been studied with ultra-short pulses at laser intensityof up to 1015Wcm-2. Three dimensional molecular dynamics calculations for finding the optimized laser pulses are presented based on time-dependent density functional theory and quantum optimal control theory. A comparison of the results for orientation dependence in the ionization process shows that the electron distribution for CH4 is more isotropic than H2CO molecule. Total conversion yields of up to 70% at an orientation angle of 30o for CH4 and 65% at 900 for H2CO are achieved which lead to enhancement of dissociation probability  

    Context-Aware ontology-based security measurement model

    , Article Journal of Information Security and Applications ; Volume 67 , 2022 ; 22142134 (ISSN) Khaleghi, M ; Aref, M. R ; Rasti, M ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    Security measurement models (SMMs) and quantitative security metrics (QSMs) are crucial pillars of systematic security measurement. How to design the enhanced SMMs and effective QSMs has been seriously considered in recent years. However, to the best of our knowledge, a desirable SMM has not yet been provided to measure the security effectiveness of a national-level network (NLN) due to its specific attributes. NLN has three main attributes, including plurality and diversity of network components, continuous changes, and simultaneous functionalities. These attributes cause three major challenges to designing a desirable SMM for NLN, including complexity, dynamic measurement, and... 

    Comprehensive comparison of security measurement models

    , Article Journal of Applied Security Research ; 2022 ; 19361610 (ISSN) Khaleghi, M ; Aref, M. R ; Rasti, M ; Sharif University of Technology
    Routledge  2022
    Abstract
    Security measurement models (SMMs) and their corresponding derived metrics form the main pillars of a systematic security measurement. Providing a desirable SMM is very challenging and has been investigated over the past two decades, so that numerous SMMs have been proposed and several surveys on SMMs have been performed. However, to the best of our knowledge, neither a systematic taxonomy nor a comprehensive comparison has yet been proposed for SMMs. This paper focuses on the comprehensive comparison of SMMs relying on a feature-based approach. The plurality and diversity of the compared SMMs enable us to deduce all the open issues. © 2021 Taylor & Francis Group, LLC  

    Comprehensive Comparison of Security Measurement Models

    , Article Journal of Applied Security Research ; Volume 18, Issue 3 , 2023 , Pages 333-401 ; 19361610 (ISSN) Khaleghi, M ; Aref, M. R ; Rasti, M ; Sharif University of Technology
    Routledge  2023
    Abstract
    Security measurement models (SMMs) and their corresponding derived metrics form the main pillars of a systematic security measurement. Providing a desirable SMM is very challenging and has been investigated over the past two decades, so that numerous SMMs have been proposed and several surveys on SMMs have been performed. However, to the best of our knowledge, neither a systematic taxonomy nor a comprehensive comparison has yet been proposed for SMMs. This paper focuses on the comprehensive comparison of SMMs relying on a feature-based approach. The plurality and diversity of the compared SMMs enable us to deduce all the open issues. © 2021 Taylor & Francis Group, LLC  

    Plug and play augmented HQS: Convergence analysis and its application in MRI reconstruction

    , Article Neurocomputing ; Volume 518 , 2023 , Pages 1-14 ; 09252312 (ISSN) Rasti Meymandi, A ; Ghaffari, A ; Fatemizadeh, E ; Sharif University of Technology
    Elsevier B.V  2023
    Abstract
    Sparse recovery in the context of the inverse problem has become an enormously popular technique in reconstructing various degraded images in various applications. One of the well-known techniques in modularizing these particular inverse problems is the Plug and Play Half-Quadratic-Splitting (PnP-HQS). This method has been demonstrated to achieve good results in the literature; however, it is still too plain to be fully exploited for reconstruction. In this regard, we introduce an augmented version of this technique dubbed “PnP-AugHQS” to efficiently utilize its capabilities in image reconstruction. We provide a comprehensive convergence analysis of the proposed algorithm to ensure its... 

    How to synchronize and register an optical-inertial tracking system

    , Article Applied Mechanics and Materials ; Volume 332 , 2013 , Pages 130-136 ; 16609336 (ISSN) ; 9783037857335 (ISBN) Soroush, A ; Akbar, M ; Farahmand, F ; Sharif University of Technology
    2013
    Abstract
    Multi-sensor tracking is widely used for augmentation of tracking accuracy using data fusion. A basic requirement for such applications is the real time temporal synchronization and spatial registration of two sensory data. In this study a new method for time and space coordination of two tracking sensor measurements has been presented. For spatial registration we used a body coordinate system and then applied the effect of the level arm. The time synchronization was done based on least mean square (LMS) error method. This method was implemented to synchronize the position and orientation of an object using Inertial (1IMU) and Optical (Optotrak) tracking systems. The results of synchronized... 

    Design and implementation of an improved real-time tracking system for navigation surgery by fusion of optical and inertial tracking methods

    , Article Applied Mechanics and Materials ; Volume 186 , 2012 , Pages 273-279 ; 16609336 (ISSN) ; 9783037854440 (ISBN) Soroush, A ; Farahmand, F ; Salarieh, H ; Sharif University of Technology
    2012
    Abstract
    The fusion of the optical and inertial tracking systems seems an attractive solution to solve the shadowing problem of the optical tracking systems, and remove the time integration troubles of the inertial sensors. We developed a fusion algorithm for this purpose, based on the Kalman filter, and examined its efficacy to improve the position and orientation data, obtained by each individual system. Experimental results indicated that the proposed fusion algorithm could effectively estimate the 2 seconds missing data of the optical tracker  

    A non-user-based BCI application for robot control

    , Article 2018 IEEE EMBS Conference on Biomedical Engineering and Sciences, IECBES 2018, 3 December 2018 through 6 December 2018 ; 2019 , Pages 36-41 ; 9781538624715 (ISBN) Zanganeh Soroush, P ; Shamsollahi, M. B ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2019
    Abstract
    Steady State Visual Evoked Potential (SSVEP) based Brain Computer Interfaces (BCI) can be great assistance for people suffering from physical disabilities due to their high accuracy, high speed, an acceptable number of possible targets, etc. Many researchers have managed to design such systems. Most of these BCIs utilize methods for frequency detection which cause the system to need a training phase for each new user, making the system a user-based one. That is why our goal was to design a BCI that not only has accuracy and speed comparable to similar systems, but also does not need any training phase and thus can be used by new users right away. Our final design got a mean accuracy of... 

    Synthesis of Metal-Organic Framework/Graphene Oxide Hybrid as an Efficient Electrode Material in Micro-Supercapacitors

    , M.Sc. Thesis Sharif University of Technology Soroush, Elham (Author) ; Khachatourian, Adrine Malek (Supervisor)
    Abstract
    The rapid development of portable and wearable electronic devices has necessitated the creation of micro-sized energy storage devices, including micro-supercapacitors. Micro-supercapacitors are ideal energy storage sources for these devices due to their lifetime and optimal power density. Consequently, selecting the appropriate electrode material and developing a simple, low-cost manufacturing method for micro-supercapacitors present significant challenges. Graphene oxide, a key material for these applications, often underperforms due to its porosity and low specific surface area. However, its performance can be enhanced by integrating it with a new class of highly porous materials with a...