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    Oseledets splitting and invariant manifolds on fields of banach spaces

    , Article Journal of Dynamics and Differential Equations ; 2021 ; 10407294 (ISSN) Ghani Varzaneh, M. M ; Riedel, S ; Sharif University of Technology
    Springer  2021
    Abstract
    We prove a semi-invertible Oseledets theorem for cocycles acting on measurable fields of Banach spaces, i.e. we only assume invertibility of the base, not of the operator. As an application, we prove an invariant manifold theorem for nonlinear cocycles acting on measurable fields of Banach spaces. © 2021, The Author(s)  

    A dynamical theory for singular stochastic delay differential equations i: linear equations and a multiplicative ergodic theorem on fields of banach spaces

    , Article SIAM Journal on Applied Dynamical Systems ; Volume 21, Issue 1 , 2022 , Pages 542-587 ; 15360040 (ISSN) Ghani Varzaneh, M ; Riedel, S ; Scheutzow, M ; Sharif University of Technology
    Society for Industrial and Applied Mathematics Publications  2022
    Abstract
    We investigate singular stochastic delay differential equations (SDDEs) in view of their long-time behavior. Using Lyons's rough path theory, we show that SDDEs can be solved pathwise and induce a continuous stochastic flow on the space of (Gubinelli's) controlled paths. In the language of random dynamical systems, this result shows that SDDEs induce a continuous cocycle on random fibers, or, more precisely, on a measurable field of Banach spaces. We furthermore prove a multiplicative ergodic theorem (MET) on measurable fields of Banach spaces that applies under significantly weaker structural and measurability assumptions than preceding METs. Applying it to linear SDDEs shows that the... 

    Correction to: Oseledets Splitting and Invariant Manifolds on Fields of Banach Spaces (Journal of Dynamics and Differential Equations, (2021), 10.1007/s10884-021-09969-1)

    , Article Journal of Dynamics and Differential Equations ; 2021 ; 10407294 (ISSN) Ghani Varzaneh, M ; Riedel, S ; Sharif University of Technology
    Springer  2021
    Abstract
    The original version of this article unfortunately contained a typo in co-author name. The author name is “Mazyar Ghani Varzaneh” instead it was published incorrectly as “M. Mazyar Ghani Varzaneh”. © 2021, Springer Science+Business Media, LLC, part of Springer Nature  

    Oseledets splitting and invariant manifolds on fields of banach spaces

    , Article Journal of Dynamics and Differential Equations ; Volume 35, Issue 1 , 2023 , Pages 103-133 ; 10407294 (ISSN) Ghani Varzaneh, M ; Riedel, S ; Sharif University of Technology
    Springer  2023
    Abstract
    We prove a semi-invertible Oseledets theorem for cocycles acting on measurable fields of Banach spaces, i.e. we only assume invertibility of the base, not of the operator. As an application, we prove an invariant manifold theorem for nonlinear cocycles acting on measurable fields of Banach spaces. © 2021, The Author(s)  

    Correction to: Oseledets splitting and invariant manifolds on fields of banach spaces (journal of dynamics and differential equations, (2023), 35, 1, (103-133), 10.1007/s10884-021-09969-1)

    , Article Journal of Dynamics and Differential Equations ; Volume 35, Issue 1 , 2023 , Pages 983- ; 10407294 (ISSN) Ghani Varzaneh, M ; Riedel, S ; Sharif University of Technology
    Springer  2023
    Abstract
    A correction to this paper has been published: https://doi.org/10.1007/s10884-021-09990-4 © 2021, Springer Science+Business Media, LLC, part of Springer Nature  

    Dynamical Properties of Rough Delay Equations

    , Ph.D. Dissertation Sharif University of Technology Ghani Varzaneh, Mazyar (Author) ; Zohuri Zangeneh, Bijan (Supervisor)
    Abstract
    In this monograph, we investigate the long-time behavior of stochastic delay equations. Our approach is random dynamical systems, and we solve our equation in the rough path point of view. Namely, we deal with the singular case, i.e., when the delay terms also are appearing in the diffusion part. Although we can solve the equation using the classical tools of stochastic analysis, the main obstacle is the lack of flow property. More precisely, the solution does not depend continuously on the initial value. To solve this problem, we define this property differently. We will show how we can generate a flow property on fields of Banach spaces using rough path theory. As a consequence, we prove... 

    A comprehensive architecture platform for smarter universities

    , Article 2023 28th International Computer Conference, Computer Society of Iran, CSICC 2023 ; 2023 ; 979-835033819-5 (ISBN) Saberi Varzaneh, A ; Merikhi, B ; Saberi Varzaneh, M ; Alam Varzaneh Isfahani, M. H ; Habibi Kalahroodi, H ; Fatemipour Sharabiany, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2023
    Abstract
    One of the most crucial infrastructure requirements of integrated systems is designing and providing a comprehensive architecture for implementation, support and improvement of their smart services or platforms. And without exception, smart University would also require a responsive architecture for the integration and consolidation of its current and future systems and services. Providing higher level of academic services, integration and consolidation support, and cost accounting (including 'cloud storage', 'computing', 'network communication and bandwidth' and energy consumption) can be placed as pivotal issues among smart university services. In this article, a basic definition of a... 

    The most optimal barrier height of InGaN light-emitting diodes

    , Article Applied Physics A: Materials Science and Processing ; Volume 127, Issue 2 , 2021 ; 09478396 (ISSN) Alam Varzaneh Isfahani, M. H ; Faez, R ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2021
    Abstract
    In this paper, a novel structure is presented in order to decrease the polarization charges of quantum wells. The main purpose of this design is to make electron and hole wavefunctions closer to each other and to increase overlap integral following an increase of radiative recombination rates and internal quantum efficiency. Furthermore, carriers will be increased and become more balanced and identical which leads to an increase in efficiency of light-emitting diodes. The improvement of radiative recombination rates is studied in new structures. Energy bands diagram, carriers density, current density–voltage, and power density–current density are used to demonstrate the superior performance... 

    The most optimal barrier height of InGaN light-emitting diodes

    , Article Applied Physics A: Materials Science and Processing ; Volume 127, Issue 2 , 2021 ; 09478396 (ISSN) Alam Varzaneh Isfahani, M. H ; Faez, R ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2021
    Abstract
    In this paper, a novel structure is presented in order to decrease the polarization charges of quantum wells. The main purpose of this design is to make electron and hole wavefunctions closer to each other and to increase overlap integral following an increase of radiative recombination rates and internal quantum efficiency. Furthermore, carriers will be increased and become more balanced and identical which leads to an increase in efficiency of light-emitting diodes. The improvement of radiative recombination rates is studied in new structures. Energy bands diagram, carriers density, current density–voltage, and power density–current density are used to demonstrate the superior performance... 

    Distributed algorithms for power saving optimization in sensor network

    , Article Proceedings of the 8th WSEAS International Conference on Data Networks, Communications, Computers, DNCOCO '09, 7 November 2009 through 9 November 2009 ; 2009 , Pages 109-115 ; 9789604741342 (ISBN) Ghani, S ; Mousavi, M ; Movaghar, A ; Sharif University of Technology
    2009
    Abstract
    Sensor networks have a wide range of potential and practical application. A sensor network consists of a large number of tiny, low power and short-living sensors. Some sensor network applications require k-coverage to ensure the quality of surveillance. Meanwhile, energy is another primary concern for sensor networks. In this dissertation, an algorithm proposed which groups sensors in to disjoint subsets. Every subset cans k-cover the whole area. The subsets are scheduled to work successively. Therefore, the network lifetime is prolonged. Furthermore, sensing range is fixed. Also another algorithm, proposed which constructs some non-disjoint subsets, and in each active subset, each sensor... 

    An internally coded time-hopping spread-time CDMA scheme for UWB systems and its performance analysis

    , Article 2007 IEEE Radio and Wireless Symposium, RWS, Long Beach, CA, 9 January 2007 through 11 January 2007 ; 2007 , Pages 511-514 ; 9781424404452(ISBN) Ghani Shayesteh, M ; Nasiri Kenari, M ; Sharif University of Technology
    2007
    Abstract
    We consider an internally coded multiple access technique for Ultra Wide-Band systems which combines time-hopping (TH) and spread-time (ST) techniques using a super-orthogonal encoder. In this method, the duration of each bit is divided into Ns frames. The outputs of a superorthogonal encoder and a PN sequence specify the frame number, in which the data is transmitted in spread-time CDMA form using the second PN sequence. We consider soft decision before Viterbi decoding at the receiver. We obtain the performance of the proposed method. We also consider the uncoded ST-CDMA system and compare its performance with our method. The results indicate that our method has much more better... 

    Performance analysis of an internally coded MC-FH-CDMA system

    , Article 2007 IEEE International Conference on Telecommunications and Malaysia International Conference on Communications, ICT-MICC 2007, Penang, 14 May 2007 through 17 May 2007 ; February , 2007 , Pages 23-28 ; 1424410940 (ISBN); 9781424410941 (ISBN) Ghani Shayesteh, M ; Nasiri Kenari, M ; Sharif University of Technology
    2007
    Abstract
    We consider an internally coded scheme for multicarrier frequency-hopping CDMA (MC-FH-CDMA) communication systems. In this method, the total bandwidth is partitioned into Ns1 disjoint bands and each band is also segmented into Ns2 subbands. Based on the super-orthogonal encoder output and a pseudorandom (PN) sequence, one of the Ns1 bands is selected. Then, the data is transmitted in that band in the form of multicarrier frequency-hopping technique using BPSK modulation. At the receiver front end, we use soft detector, then we apply Viterbi decoding algorithm. We evaluate the performance of the proposed method. The results indicate that our method outperforms the previously presented uncoded... 

    Attitude and Deformation Estimation of Flexible Satellite Using Magnetometer and Sun Sensor

    , M.Sc. Thesis Sharif University of Technology Ghani, Marzieh (Author) ; Asadian, Nima (Supervisor)
    Abstract
    The estimation of attitude and deformation of a flexible satellite using magnetometer and sun sensor data are studied in this thesis. To this end, the dynamical differential equations of the flexible satellite have been derived using Lagrange’s equation. These equations of motion are then utilized for the purpose of simulation and verification. After introducing the measurements equations, the observability of the satellite with flexible panels has been evaluated. Afterward, the attitude of the satellite body and deformation of the flexible panels have been estimated by EKF (Extended Kalman Filter) as well as UKF (Unscented Kalman Filter). The results show that the estimations using UKF are... 

    Study of structural, electrical, and electrochemical properties of Sr3-xPrxFe1.8Co0.2O7-δ cathode for IT-SOFCs

    , Article Solid State Ionics ; Volume 404 , 2024 ; 01672738 (ISSN) Ghani Harzand, A ; Golmohammad, M ; Zargar, A ; Khachatourian, A. M ; Nemati, A ; Sharif University of Technology
    2024
    Abstract
    Developing new cathode materials for intermediate-temperature solid oxide fuel cells (IT-SOFCs) is still challenging. In this study, co-doped Sr3Fe2O7-δ Ruddlesden-Popper (R-P) (Sr3-xPrxFe1.8Co0.2O7-δ x = (0–0.3)) cathode is synthesized by the polymer complex technique as a cathode for IT-SOFCs. The synthesized powders show a desired tetragonal structure of Sr3-xPrxFe1.8Co0.2O7-δ with an I4/mmm space group. The effect of Pr and Co on the physical, thermal, electrical, and electrochemical properties of the cathodes is investigated. The results reveal that Pr/Co co-doping improves electrochemical properties while increasing the electrical resistivity and average thermal expansion coefficients... 

    An Introduction to Langlands Program

    , M.Sc. Thesis Sharif University of Technology Hatami Varzaneh, Omid (Author) ; Pournaki, Mohammadreza (Supervisor)
    Abstract
    The Weil group WF is assigne to every local field F. Langlands Correspondence is a bijetion between semisimple two-dimensional Deligne representations of Weil Group WF and irreducible representations of GL2(F) which fixes assigned L-functions and local constants. In this thesis we have classified an important class of irreducible representations of GL(2) over local fields called Principal Series. We also tried to give a taste of Langlands Correspondence to the reader. First we explain preliminaries and introduce locally profinite groups and their smooth representations. Then we classify representations of GL2(F) when F is finite. Then we study GL2(F) when F is a local field. Finally we... 

    Simulation and Implementation of Active Energy Management Algorithm on Residential Photovoltaic System with Storage

    , M.Sc. Thesis Sharif University of Technology Ghafouri Varzaneh, Saeed (Author) ; Abbaspour, Ali (Supervisor)
    Abstract
    In majority of the (standalone or grid-connected) PV Systems, predefined rule-based algorithms are utilized in order to manage and control the flow of power. The function of these algorithms is to send the generated energy from solar panels either to load for consumption, or to battery for storage, or to the grid for sale. Their performance is based on predefined instructions and regardless of load change and consumption patterns. Therefore the total efficiency of these systems depend greately upon individual user’s load type and consumption pattern. In current research, an optimum and dynamic energy management algorithm is proposed using dynamic programming (DP) method, in order to increase... 

    Attitude and deformation coupled estimation of flexible satellite using low-cost sensors

    , Article Advances in Space Research ; Volume 69, Issue 1 , 2022 , Pages 677-689 ; 02731177 (ISSN) Ghani, M ; Assadian, N ; Varatharajoo, R ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    Solar panel flexibility plays an important role in the attitude control of satellites. Therefore, traditionally the deformations of flexible solar panels are measured with a series of sensors along the panels itself. This paper presents a novel maiden attempt to simultaneously estimate the attitude and deformation of a flexible satellite using only 2 low-cost attitude sensors namely the sun sensor and magnetometer measurements. The flexible satellite is considered as a central rigid body with two attached flexible panels in order to derive the governing dynamic equations based on the Lagrange's equation. Both Extended Kalman filter (EKF) and Unscented Kalman Filter (UKF) are employed for the... 

    Analysis of Specular and Off-Specular Scattering in Millimeter-Wave and Terahertz Applications

    , Ph.D. Dissertation Sharif University of Technology Ghani, Hossein (Author) ; Ahmadi Boroujenir, Mehdi (Supervisor)
    Abstract
    In this dissertation, the problem of wave propagation and scattering modeling in multilayer structures with rough interfaces in the terahertz and millimeter-wave frequency bands is investigated. Due to the short wavelengths in these bands, the surface roughness of materials attenuates the specular component and generates extensive off-specular scattering, which poses challenges for the design of sixth-generation communication systems and non-destructive testing. In the first part of this research, two matrix frameworks are developed to predict the specular component. First, the Rough-Surface Transfer Matrix Method is presented, which directly embeds Gaussian roughness statistics into... 

    Approximation Algorithms for Clustering Points in the Data Stream Model

    , M.Sc. Thesis Sharif University of Technology Hatami Varzaneh, Behnam (Author) ; Zarrabi Zadeh, Hamid (Supervisor)
    Abstract
    The k-center problem—covering a set of points using k congruent balls with minimum radius—is a well-known clustering model in computer science with a wide range of applications. The k-center is a well known NP-Hard problem. In this thesis, we focus on the k-center problem with outliers in high dimensional data streams. Due to increase in data size, we focus on the data stream model of the problem. Moreover, in real-world applications, where input points are noisy, it is very important to consider outliers. In this thesis, we study 1-center and 2-center with outliers in high dimensional data streams in Euclidean space. We provide a 1:7-approximation streaming algorithm for 1-center with z... 

    The Role of Green HRM on Environmental Performance: Mediating Role of Green Ambidexterity and Green Behavior and Moderating Role of Responsible Leadership

    , Article Journal of Chinese Human Resources Management ; Volume 15, Issue 2 , 2024 , Pages 70-90 ; 20408005 (ISSN) Jabeen, R ; Mehmood, S ; Ahmed, M ; Ghani, T ; Javaid, Z. K ; Popp, J ; Sharif University of Technology
    2024
    Abstract
    The purpose of this research is to explore the influence of Green HRM (GHRM) on environmental performance (EP). There has been a noticeable lack of focus on concurrently examining green ambidexterity (GA), GHRM, green behavior (GB), and their combined impact on EP in the lens of Human Capital theory. The purpose of this study is to investigate the interrelationship between GHRM and EP through serial mediation of GA and GB with a moderating role of responsible leadership (RL) in the relationship of GHRM and GA. A variance-based structural equation modeling (PLS-SEM) was applied to 570 sample of hotels. The results indicate that GHRM facilitates the development of green ambidexterity, and...