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    Load frequency control (LFC) strategies in renewable energy‐based hybrid power systems: a review

    , Article Energies ; Volume 15, Issue 10 , 2022 ; 19961073 (ISSN) Gulzar, M. M ; Iqbal, M ; Shahzad, S ; Muqeet, H. A ; Shahzad, M ; Hussain, M. M ; Sharif University of Technology
    MDPI  2022
    Abstract
    The hybrid power system is a combination of renewable energy power plants and conventional energy power plants. This integration causes power quality issues including poor settling times and higher transient contents. The main issue of such interconnection is the frequency variations caused in the hybrid power system. Load Frequency Controller (LFC) design ensures the reliable and efficient operation of the power system. The main function of LFC is to maintain the system frequency within safe limits, hence keeping power at a specific range. An LFC should be supported with modern and intelligent control structures for providing the adequate power to the system. This paper presents a... 

    Comparison between Lagrangian and Eulerian approaches in predicting motion of micron-sized particles in laminar flows

    , Article Atmospheric Environment ; Vol. 89, issue , 2014 , Pages 199-206 ; ISSN: 13522310 Saidi, M. S ; Rismanian, M ; Monjezi, M ; Zendehbad, M ; Fatehiboroujeni, S ; Sharif University of Technology
    2014
    Abstract
    Modeling the behavior of suspended particles in gaseous phase is important for diverse reasons; e.g. aerosol is usually the main subject of CFD simulations in clean rooms. Additionally, to determine the rate and sites of deposition of particles suspended in inhaled air, the motion of the particles should be predicted in lung airways. Meanwhile there are two basically different approaches to simulate the behavior of particles suspension, Lagrangian and Eulerian approaches. This study compares the results of these two approaches on simulating the same problem. An in-house particle tracking code was developed to simulate the motion of particles with Lagrangian approach. In order to simulate the... 

    The generalized MAC with partial state and message cooperation

    , Article IWCIT 2014 - Iran Workshop on Communication and Information Theory ; May , 2014 ; 978-1-4799-4878-9 Emadi, M. J ; Khormuji, M. N ; Skoglund, M ; Aref, M. R ; Sharif University of Technology
    2014
    Abstract
    We consider a two-user state-dependent generalized multiple access channel (GMAC) with correlated channel state information (CSI). It is assumed that the CSI is partially known at each encoder noncausally. We first present an achievable rate region using multi-layer Gelfand-Pinsker coding with partial state and message cooperation between the encoders. We then specialize our result to a Gaussian GMAC with additive interferences that are known partially at each encoder. We show that the proposed scheme can remove the common part known at both encoders and also mitigate a significant part of the independent interference via state cooperation when the feedback links are strong. Thus, the... 

    Numerical analysis (finite element method) of brace effects on the adolescent idiopathic scoliosis during 24 hours

    , Article Biomedical Engineering - Applications, Basis and Communications ; Vol. 26, issue. 3 , June , 2014 ; 10162372 Gohari, E ; Haghpanahi, M ; Parnianpour, M ; Ganjavian, M. S ; Kamyab, M ; Sharif University of Technology
    2014
    Abstract
    In the adolescent idiopathic scoliosis (AIS) treatment, a brace is prescribed to the patients who have 20 to 45° curves on their spines to prevent the disorder's advancement. For the analysis of Milwaukee brace effects during time, finite element models (FEMs) of the spine (the thoracolumbar region) and the ribcage (contained 10 pairs of the ribs and the sternum) were prepared for two patients. For modeling the spine part, a new element was used in which a disc (as viscoelastic 3D beam) and a vertebra (as rigid link) were modeled as an element and the ribs and the sternum modeled by 3D elastic beams. The gravity, Milwaukee brace constraints and the forces of the brace's different regions... 

    Multi-layer Gelfand-Pinsker strategies for the generalised multiple-access channel

    , Article IET Communications ; Vol. 8, issue. 8 , 2014 , p. 1296-1308 Emadi, M. J ; Khormuji, M. N ; Skoglund, M ; Aref, M. R ; Sharif University of Technology
    2014
    Abstract
    The authors study a two-user state-dependent generalised multiple-access channel (GMAC) with correlated states. It is assumed that each encoder has 'non-causal' access to channel state information (CSI). They develop an achievable rate region by employing rate-splitting, block Markov encoding, Gelfand-Pinsker multicoding, superposition coding and joint typicality decoding. In the proposed scheme, the encoders use a partial decoding strategy to collaborate in the next block, and the receiver uses a backward decoding strategy with joint unique decoding at each stage. The author's achievable rate region includes several previously known regions proposed in the literature for different scenarios... 

    On the achievable rate region of a state-dependent MAC with cooperating encoders

    , Article 2012 Swedish Communication Technologies Workshop, Swe-CTW 2012 ; 2012 , Pages 48-52 ; 9781467347631 (ISBN) Emadi, M. J ; Khormuji, M. N ; Skoglund, M ; Aref, M. R ; Sharif University of Technology
    2012
    Abstract
    The two-user discrete memoryless state-dependent multiple-access channel with cooperating encoders is considered. It is assumed that the channel is controlled with two independent states such that each of the channel state information is noncausally available at one encoder. Moreover, based on the intrinsic characteristic of wireless networks, it is assumed that each encoder strictly causally receive a noisy version of the transmitted signal of the other encoder. Hence, the encoders can cooperate in transmitting the message to the receiver. An achievable rate region for the channel is derived by use of rate splitting, block Markov encoding and Gelfand-Pinsker multilevel encoding along with... 

    Transversal thermal transport in single-walled carbon nanotube bundles: Influence of axial stretching and intertube bonding

    , Article Journal of Chemical Physics ; Volume 139, Issue 18 , 2013 ; 00219606 (ISSN) Gharib Zahedi, M. R ; Tafazzoli, M ; Böhm, M. C ; Alaghemandi, M ; Sharif University of Technology
    2013
    Abstract
    Using reverse nonequilibrium molecular dynamics simulations the influence of intermolecular bridges on the thermal conductivity (λ) in carbon nanotube (CNT) bundles has been investigated. The chosen cross linkers (CH 2, O, CO) strengthen the transversal energy transport relative to the one in CNT bundles without bridges. The results showed that λ does not increase linearly with the linker density. The efficiency of the heat transport is determined by the number of linkers in the direction of the heat flux, the type of the linker, and their spatial ordering. The influence of a forced axial stress on the transversal λ has been also studied. The observed λ reduction with increasing axial... 

    A comparison of carbon coated and uncoated 316L stainless steel for using as bipolar plates in PEMFCs

    , Article Journal of Alloys and Compounds ; Volume 509, Issue 27 , July , 2011 , Pages 7400-7404 ; 09258388 (ISSN) Larijani, M. M ; Yari, M ; Afshar, A ; Jafarian, M ; Eshghabadi, M ; Sharif University of Technology
    2011
    Abstract
    Two kinds of carbon coated and uncoated 316L stainless steel are studied to use as bipolar plates in fuel cells. The results show that the conductive amorphous carbon film has a low corrosion rate in simulated PEMFC environment. Rather long term potentiostatic tests and SEM investigations indicate that carbon thin films can be a good candidate to use as bipolar plate  

    Synthesis of quinazolin-4(3H)-one derivatives using heteropolyacids as heterogeneous and recyclable catalysts

    , Article Asian Journal of Chemistry ; Volume 23, Issue 4 , 2011 , Pages 1588-1590 ; 09707077 (ISSN) Allameh, S ; Hashemi, M. M ; Heravi, M. M ; Bamoharram, F. F ; Sharif University of Technology
    2011
    Abstract
    A highly efficient and simple procedure for the synthesis of quinazolin-4(3H)-ones from the condensation of 2-aminobenzamide with triethylorthoesters in presence of a catalytic amounts of heteropolyacids in various solvents is reported  

    Geometrical optimization of half toroidal continuously variable transmission using particle swarm optimization

    , Article Scientia Iranica ; Volume 18, Issue 5 , 2011 , Pages 1126-1132 ; 10263098 (ISSN) Delkhosh, M ; Saadat Foumani, M ; Boroushaki, M ; Ekhtiari, M ; Dehghani, M ; Sharif University of Technology
    2011
    Abstract
    The objective of this research is geometrical optimization of half toroidal Continuously Variable Transmission (CVT) in order to achieve high power transmission efficiency. The dynamic analysis of CVT is implemented and contact between the disk and the roller is modeled viaelastohydrodynamic (EHL) lubrication principles. Computer model is created using geometrical, thermal and kinetic parameters to determine the efficiency of CVT. Results are compared by other models to confirm the model validity. Geometrical parameters are obtained by means of Particle Swarm Optimization (PSO) algorithm, while the optimization objective is to maximize the power transmission efficiency. Optimization was... 

    Comprehensive control framework for ensuring loading margin of power systems considering demand-side participation

    , Article IET Generation, Transmission and Distribution ; Volume 6, Issue 12 , 2012 , Pages 1189-1201 ; 17518687 (ISSN) Rabiee, A ; Parvania, M ; Vanouni, M ; Parniani, M ; Fotuhi Firuzabad, M ; Sharif University of Technology
    2012
    Abstract
    This study presents a comprehensive control framework to ensure desired loading margin (LM) while minimising the corresponding control cost. The proposed framework is divided into corrective control (CC) and preventive control (PC) subproblems. The CC subproblem deals with the condition that a power system encounters voltage instability as a result of severe contingencies. This control is merely devised to restore system stability. The PC subproblem is brought up when the system operates in a stable region but its LM is insufficient. In this manner, the system-operating point is changed such that the desired LM is achieved. One of the features of the proposed methodology is to consider... 

    Multi-layer Gelfand-Pinsker strategies for the generalized multiple-access channel

    , Article 2013 Iran Workshop on Communication and Information Theory ; 2013 ; 9781467350235 (ISBN) Emadi, M. J ; Khormuji, M. N ; Skoglund, M ; Aref, M. R ; Sharif University of Technology
    2013
    Abstract
    We study a two-user state-dependent generalized multiple-access channel (GMAC) with correlated states. It is assumed that each encoder noncausally knows partial channel state information. We develop an achievable rate region by employing rate-splitting, block Markov encoding, Gelfand-Pinsker multicoding, superposition coding and jointly typical decoding. In the proposed scheme, the encoders use a partial decoding strategy to collaborate in the next block, and the receiver uses a backward decoding strategy with a joint unique decoding at each stage. Our achievable rate region includes several previously known rate regions proposed in the literature for different scenarios of multiple-access... 

    Comprehensive study of non-uniform circular array interferometer in a real time broadband 3-dimensional direction finder (2-12GHZ)

    , Article Progress In Electromagnetics Research C ; Volume 24 , 2011 , Pages 69-81 ; 19378718 (ISSN) Ebrahimi Ganjeh, M. A ; Soltanian, M ; Salarpour, M ; Pezeshk, A. M ; Sharif University of Technology
    2011
    Abstract
    A comprehensive study is performed to investigate the performance of a non-uniform circular array interferometer in a real time 3-dimensional direction finder. The angular range of view is supposed to be 65 degrees vertically and 120 degrees horizontally, which is suitable for airborne applications. Interferometer is designed to work in the S, C and X bands. Regarding optimization process, the interferometer employs an eight element non-uniform circular array along with a phase reference antenna at the center of the array. Several quantities and parameters are studied, e.g., frequency behavior, origins of phase measurement errors, Signal to Noise Ratio (SNR) effect on phase measurement, and... 

    Investigation on a developed wearable assistive device (WAD) in reduction lumbar muscles activity

    , Article Biomedical Engineering - Applications, Basis and Communications ; Volume 25, Issue 3 , 2013 ; 10162372 (ISSN) Heydari, H ; Hoviattalab, M ; Azghani, M. R ; Ramezanzadehkoldeh, M ; Parnianpour, M ; Sharif University of Technology
    2013
    Abstract
    A new wearable assistive device (WAD) was developed to decrease required force on the lumbar spine in static holding tasks. In order to obtain moments on lumbar spine in two conditions, with and without WAD, a biomechanical static model was used for estimation of external moments on lumbar spine. The results of biomechanical models indicated that there was a reduction in the lumbar moment ranging from 20% to 43% using WAD depending on the load and flexion angle. A total of 15 male healthy subjects were tested to experimentally verify the predicted reduction of external moments on the spine by wearing WAD. Normalized electromyography (EMG) of the right and left lumbar and thoracic erector... 

    Computational and experimental investigations of boundary layer tripping

    , Article Journal of Applied Fluid Mechanics ; Volume 3, Issue 2 , 2010 , Pages 53-63 ; 17353572 (ISSN) Heidari, M. R ; Soltani, M. R ; Farahani, M ; Taeibi Rahni, M ; Sharif University of Technology
    2010
    Abstract
    Supersonic flow over a tapered body of revolution has been investigated both experimentally and numerically. The experimental study consisted of a series of wind tunnel tests on an ogive-cylinder body. Static pressure distributions on the body surfaces at several longitudinal cross sections, as well as the boundary layer profiles at various angles of attack have been measured. Further, the flow around the model was visualized using Schlieren technique. Tests with a natural development of the boundary layer and with tripping were also carried out. All tests were conducted in the trisonic wind tunnel of Qadr Research Center. Our results show that artificial boundary layer tripping has minor... 

    Statistical performance analysis of MDL source enumeration in array processing

    , Article IEEE Transactions on Signal Processing ; Volume 58, Issue 1 , 2010 , Pages 452-457 ; 1053587X (ISSN) Haddadi, F ; Malek Mohammadi, M ; Nayebi, M. M ; Aref, M. R ; Sharif University of Technology
    2010
    Abstract
    In this correspondence, we focus on the performance analysis of the widely-used minimum description length (MDL) source enumeration technique in array processing. Unfortunately, available theoretical analysis exhibit deviation from the simulation results. We present an accurate and insightful performance analysis for the probability of missed detection.We also show that the statistical performance of the MDL is approximately the same under both deterministic and stochastic signal models. Simulation results show the superiority of the proposed analysis over available results  

    Interfacial thermal transport and structural preferences in carbon nanotube-polyamide-6,6 nanocomposites: How important are chemical functionalization effects?

    , Article Physical Chemistry Chemical Physics ; Volume 17, Issue 22 , 2015 , Pages 14502-14512 ; 14639076 (ISSN) Gharib Zahedi, M. R ; Tafazzoli, M ; Böhm, M. C ; Alaghemandi, M ; Sharif University of Technology
    Royal Society of Chemistry  2015
    Abstract
    We employ reverse nonequilibrium molecular dynamics simulations to investigate the interfacial heat transfer in composites formed by an ungrafted or a grafted carbon nanotube which is surrounded by oligomeric polyamide-6,6 chains. The structural properties of the polymer matrix and the grafted chains are also studied. The influence of the grafting density, the length of the grafted chains as well as their chemical composition on the interfacial thermal conductivity (λi) are in the focus of our computational study. For the considered grafted polyethylene and polyamide chains we do not find a sizeable difference in the observed λi values. In contrast to this... 

    RETRACTED: First principles study of the I-V characteristics of the alkane-thiols nano-molecular wires (9(2) (2009) 367-373) (DOI:10.1016/j.cap.2008.03.014)

    , Article Current Applied Physics ; Volume 9, Issue 5 , 2009 , Pages 1180- ; 15671739 (ISSN) Aghaie, H ; Gholami, M. R ; Ganji, M. D ; Taghavi, M. M ; Sharif University of Technology
    Elsevier  2009

    More details on analysis of fractional-order Van der Pol oscillator

    , Article JVC/Journal of Vibration and Control ; Volume 15, Issue 6 , 2009 , Pages 803-819 ; 10775463 (ISSN) Tavazoei, M. S ; Haeri, M ; Attari, M ; Bolouki, S ; Siami, M ; Sharif University of Technology
    2009
    Abstract
    This paper is devoted to the analysis of fractional order Van der Pol system studied in the literature. Based on the existing theorems on the stability of incommensurate fractional order systems, we determine parametric range for which a fractional order Van der Pol system with a specific order can perform as an undamped oscillator. Numerical simulations are presented to support the given analytical results. These results also illuminate a main difference between oscillations in a fractional order Van der Pol oscillator and its integer order counterpart. We show that contrary to integer order case, trajectories in a fractional Van der Pol oscillator do not converge to a unique cycle. © 2009... 

    First principles study of the I-V characteristics of the alkane-thiols nano-molecular wires

    , Article Current Applied Physics ; Volume 9, Issue 2 , 2009 , Pages 367-373 ; 15671739 (ISSN) Aghaie, H ; Gholami, M. R ; Darvish Ganji, M ; Taghavi, M. M ; Sharif University of Technology
    2009
    Abstract
    We report a density functional non-equilibrium Green's function study of electrical transport in a single molecular conductor consisting of an ethane-dithiolate (C2H4S2) molecular wire with two sulfur end groups bonded to the Au(1 1 1) electrodes. We show that the current was increased by increasing the external voltage biases. The projected density of states (PDOS) and transmission coefficients T(E) under various external voltage biases are analyzed, and it suggests that the variation of the coupling between the molecule and the electrodes with external bias leads to the increase of the current. Furthermore, the investigation of the transport properties of the pentane-dithiolate (C5H10S2)...