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Efficient hardware implementations of legendre symbol suitable for Mpc applications
, Article IEEE Transactions on Circuits and Systems I: Regular Papers ; Volume 69, Issue 3 , 2022 , Pages 1231-1239 ; 15498328 (ISSN) ; Bayat Sarmadi, S ; Ebrahimi, S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
Multi-party computation (MPC) allows each peer to take part in the execution of a common function with their private share of data without the need to expose it to other participants. The Legendre symbol is a pseudo-random function (PRF) that is suitable for MPC protocols due to their efficient evaluation process compared to other symmetric primitives. Recently, Legendre-based PRFs have also been employed in the construction of a post-quantum signature scheme, namely LegRoast. In this paper, we propose, to the best of our knowledge, the first hardware implementations for the Legendre symbol by three approaches: 1) low-area, 2) high-speed, and 3) high-frequency. The high-speed architecture...
Quaternion based linear time-varying model predictive attitude control for satellites with two reaction wheels
, Article Aerospace Science and Technology ; Volume 98 , March , 2020 ; ISSN: 12709638 ; Nejat Pishkenari, H ; Salarieh, H ; Abdollahi, T ; Sharif University of Technology
Elsevier Masson SAS
2020
Abstract
Attitude control of a satellite having only two reaction wheels is a challenging issue. To address this problem, previously published researches considered some simplifying assumptions on the satellites such as diagonality of the moment of the inertia matrix. On the other hand, in some works, the total angular momentum of the satellite is assumed to be zero. In this paper, a linear time-variant model predictive control (LTV MPC) is designed to control a satellite with two reaction wheels. This control method can be applied to a satellite with a non-diagonal inertial matrix in the presence of external torques, to rotate the satellite toward the desired directions in the space and orbit. The...
Coded Secure multi-party computation for massive matrices with adversarial nodes
, Article 2020 Iran Workshop on Communication and Information Theory, IWCIT 2020, 26 May 2020 through 28 May 2020 ; 2020 ; Maddah Ali, M. A ; Aref, M. R ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
In this work1, we consider the problem of secure multi-party computation (MPC), consisting of F sources, each has access to a large private matrix, N processing nodes or workers, and one master. The master is interested in the result of a polynomial function of the input matrices. Each source sends a randomized functions of its matrix, called as its share, to each server. The workers process their shares in interaction with each other, and send some results to the master such that it can derive the final results. There are several constraints: (1) each worker has a constraint on its storage, such that it can store equivalent of displaystyle rac{1}{m} fraction of size of each input matrices...
Intelligent trajectory tracking of an aircraft in the presence of internal and external disturbances
, Article International Journal of Robust and Nonlinear Control ; Volume 29, Issue 16 , 2019 , Pages 5820-5844 ; 10498923 (ISSN) ; Banazadeh, A ; Sharif University of Technology
John Wiley and Sons Ltd
2019
Abstract
This research deals with developing an intelligent trajectory tracking control approach for an aircraft in the presence of internal and external disturbances. Internal disturbances including actuators faults, unmodeled dynamics, and model uncertainties as well as the external disturbances such as wind turbulence significantly affect the performance of the common trajectory tracking control approaches. There are several fault-tolerant control approaches in the literature to overcome the effects of specific actuator or sensor faults during the flight. However, trajectory tracking control of an air vehicle in the presence of unexpected faults and simultaneous presence of wind turbulence is...
Enhanced hybrid modular multilevel converter with improved reliability and performance characteristics
, Article IEEE Transactions on Power Electronics ; Volume 34, Issue 4 , 2019 , Pages 3139-3149 ; 08858993 (ISSN) ; Ravanji, M. H ; Parniani, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
This paper proposes an enhanced hybrid modular multilevel converter (MMC), which utilizes a combination of half-bridge submodules (HBSM) and at least one full-bridge submodule (FBSM). In the proposed structure, FBSMs work with half of the HBSMs nominal voltage in each arm. Due to the presence of FBSMs, HBSMs switching frequency drops significantly, which reduces the converter power loss compared to half-bridge based MMCs. Furthermore, because of redundant FBSMs, (2N + 1)-modulation can be employed to generate the output voltage without increasing the circulating current, thus, the converter performance is improved notably. Besides, with the redundant FBSMs, the converter can continue its...
Design and simulation of new soft-switched three-port half bridge converter with extended zvs range
, Article 27th Iranian Conference on Electrical Engineering, ICEE 2019, 30 April 2019 through 2 May 2019 ; 2019 , Pages 602-608 ; 9781728115085 (ISBN) ; Jahani, M ; Oraee, H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
Multi-port converters (MPC), used in multi-input/multi-output power electronic systems have low cost, low weight and low mass integrated control system. Besides these converters offer bidirectional and isolated ports, which are inevitable in some applications. Three-Port Half Bridge Converters (TPHBC) are the ones which have the lowest component count. But these converters suffer from a low Zero Voltage Switching (ZVS) range that is lost in medium to low load powers. Low ZVS range cause low efficiency, especially in low output powers. In this paper a modified Pulse Width Modulation (PWM) technique is introduced to increase the ZVS range of main switches which results higher efficiency and...
An enhanced hybrid modular multilevel converter for improved performance
, Article IEEE Transactions on Power Electronics ; 2018 ; 08858993 (ISSN) ; Ravanji, M. H ; Parniani, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
This paper proposes an enhanced hybrid modular multilevel converter (MMC), which utilizes a combination of halfbridge submodules (HBSM) and at least one full-bridge submodule (FBSM). In the proposed structure, FBSMs work with half of the HBSMs nominal voltage in each arm. Due to the presence of FBSMs, HBSMs switching frequency drops significantly, which reduces the converter power loss compared to half-bridge based MMCs. Furthermore, because of redundant FBSMs, (2N+1)-modulation can be employed to generate the output voltage without increasing the circulating current, thus the converter performance is improved notably. Besides, with the redundant FBSMs the converter can continue its...
Role of outage management strategy in reliability performance of multi-microgrid distribution systems
, Article IEEE Transactions on Power Systems ; Volume 33, Issue 3 , May , 2018 , Pages 2359-2369 ; 08858950 (ISSN) ; Fotuhi Firuzabad, M ; Moeini Aghtaie, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
This paper develops a general framework for reliability assessment of multi-microgrid (MMG) distribution systems. It also investigates reliability impacts of coordinated outage management strategies in a MMG distribution network. According to the proposed reliability evaluation framework, which is based on sequential Monte Carlo simulation method, distribution system is divided into smaller sections/microgrids based on protection system configuration and operating measures are efficiently simulated considering different operation modes. In order to demonstrate the role of outage management strategy in reliability performance of MMG distribution systems, at first, the required features of an...
Predictive fault-tolerant control of an all-thruster satellite in 6-DOF motion via neural network model updating
, Article Advances in Space Research ; Volume 61, Issue 6 , March , 2018 , Pages 1588-1599 ; 02731177 (ISSN) ; Assadian, N ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
The problem of controlling an all-thruster spacecraft in the coupled translational-rotational motion in presence of actuators fault and/or failure is investigated in this paper. the nonlinear model predictive control approach is used because of its ability to predict the future behavior of the system. The fault/failure of the thrusters changes the mapping between the commanded forces to the thrusters and actual force/torque generated by the thruster system. Thus, the basic six degree-of-freedom kinetic equations are separated from this mapping and a set of neural networks are trained off-line to learn the kinetic equations. Then, two neural networks are attached to these trained networks in...
A hierarchical scheme for outage management in multi-microgrids
, Article International Transactions on Electrical Energy Systems ; Volume 26, Issue 9 , 2016 , Pages 2023-2037 ; 20507038 (ISSN) ; Moeini Aghtaie, M ; Fotuhi Firuzabad, M ; Sharif University of Technology
John Wiley and Sons Ltd
2016
Abstract
This paper investigates the operation of a smart distribution system comprised of multiple microgrids during emergency conditions. It proposes a two-stage hierarchical scheme for outage management in such a system to enhance the security of supply during contingencies. This goal is achieved through sharing the available generation and storage capacities among different microgrids. In doing so, a well-organized framework is devised in order to introduce the roles and tasks of each player in operation stage of a multi-microgrids system. Based on this framework, the general optimization model that needs to be evaluated at each stage of the proposed outage management scheme is formulated. In...
Robust model predictive control of nonlinear processes represented by Wiener or Hammerstein models
, Article Chemical Engineering Science ; Volume 129 , 2015 , Pages 223-231 ; 00092509 (ISSN) ; Haeri, M ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
Representing nonlinear systems by linear models along with structured or unstructured uncertainties and applying robust control strategies could reduce the computational complexity in comparison with implementing the nonlinear model predictive controllers. In this paper design of robust model predictive controllers which are based on special classes of nonlinear systems representations called Wiener and Hammerstein are presented. The proposed algorithms approximate the nonlinear systems by uncertain linear models and reduce online the computational demands in the control implementation. The advantages of the proposed approaches are illustrated by two examples
Robustness investigation of a ducted-fan aerial vehicle control, using linear, adaptive, and model predictive controllers
, Article International Journal of Advanced Mechatronic Systems ; Volume 6, Issue 2-3 , 2015 , Pages 108-117 ; 17568412 (ISSN) ; Banazadeh, A ; Sharif University of Technology
Inderscience Publishers
2015
Abstract
A comparison of three common controllers for stabilising a vertical take-off and landing air vehicle is presented. RMIT is a small sized tail-sitter ducted fan air vehicle with a particular configuration layout, multiple control surfaces, low weight, and high-speed flight capability. The main problem here is control effectiveness at low flight speeds and transition manoeuvres because of the inherent instability. In the current study, a comprehensive nonlinear model is firstly developed for RMIT, followed by a validation process. Subsequently, linear, adaptive and model predictive controllers are designed in vertical flight. Based on the simulation results, it is shown that the linear...
Robust multivariable predictive based load frequency control considering generation rate constraint
, Article International Journal of Electrical Power and Energy Systems ; Volume 46, Issue 1 , March , 2013 , Pages 405-413 ; 01420615 (ISSN) ; Toulabi, M. R ; Ranjbar, A. M ; Sharif University of Technology
2013
Abstract
In this paper, a robust multivariable Model based Predictive Control (MPC) is proposed for the solution of load frequency control (LFC) in a multi-area power system. The proposed control scheme is designed to consider multivariable nature of LFC, system uncertainty and generation rate constraint, simultaneously. A constrained MPC is employed to calculate optimal control input including generation rate constraints. Economic allocation of generation is further ensured by modification of the predictive control objective function. To achieve robustness against system uncertainty and variation of parameters, a linear matrix inequality (LMI) based approach is employed. To validate the...
A new method to control heat and mass transfer to work piece in a GMAW process
, Article Journal of Process Control ; Volume 22, Issue 6 , 2012 , Pages 1087-1102 ; 09591524 (ISSN) ; Haeri, M ; Sharif University of Technology
2012
Abstract
It is proposed to employ melting rate, heat input, and detaching droplet diameter as controlled variables to control heat and mass transfer to work piece in a gas metal arc welding process. A two-layer architecture with cascade configuration of PI and MPC controllers is implemented to incorporate existing constraints on the process variables, improve transient behavior of the closed-loop responses and reduce interaction level. Computer simulation results are presented to indicate usefulness of the proposed controlled variables selection and applying two-layer control architecture to control heat and mass transfer to work piece
Global hybrid modeling and control of a buck converter: a novel concept
, Article International Journal of Circuit Theory and Applications ; Volume 37, Issue 9 , 2009 , Pages 968-986 ; 00989886 (ISSN) ; Mokhtari, H ; Sharif University of Technology
2009
Abstract
Several attempts have been made to design suitable controllers for DC-DC converters. However, these designs suffer from model inaccuracy or their inability to desirably function in both continuous and discontinuous current modes. This paper presents a novel switching scheme based on hybrid modeling to control a buck converter using mixed logical dynamical (MLD) methodologies. The proposed method is capable of globally controlling the converter in both continuous and discontinuous current modes of operation by considering all constraints in the physical plant such as maximum inductor current and capacitor voltage limits. Different loads and input voltage disturbances are simulated in MATLAB...
Transition Flight Control of a Tilt Tri-Rotor UAV Using Robust Model Predictive Control
, M.Sc. Thesis Sharif University of Technology ; Nobahari, Hadi (Supervisor) ; Emami, Ali (Co-Supervisor)
Abstract
The purpose of this thesis is to control altitude and attitude of a Tilt Tri-Rotor UAV in rotorcraft mode and control of altitude, attitude and forward velocity in transition mode (from rotorcraft mode to cruise) by using model predictive control. First, the detailed mathematical model is obtained by the Newton-Euler equations of motion, in both rotorcraft and transition modes. In the next step, a MIMO model predictive controller has been designed, considering input constraints. Then, since, robustness of the model-based control approach is an important challenge, the performance of the controller is presented in the presence of model uncertainties and wind disturbances. The results indicate...
Blood Glucose Control for Type 1 Diabetes Patients with Explicit Model Predictive Control (MPC)
, M.Sc. Thesis Sharif University of Technology ; Alasty, Aria (Supervisor) ; Vahidi, Omid (Co-Supervisor)
Abstract
Blood glucose regulation in type 1 diabetes patients requires the delivery of the proper amount of insulin from an external source. The literature of Blood Glucose Control signifies the superiority of model-based controllers over the other ones. Regarding its lack of need to complicated on-line calculations and the simplicity of its implementation on a micro-chip, the explicit Model Predictive Controller is preferred over the implicit MPC. Currently proposed explicit MPC controllers have employed relatively simple models representing human glucose-insulin dynamics. In this thesis, an explicit MPC controller is designed using mp-QP based on Sorensen’s 19-state comprehensive model which has...
Model Predictive Control Applications in Turbocompressor Control System
, Ph.D. Dissertation Sharif University of Technology ; Alasty, Aria (Supervisor) ; Vossoughi, Gholamreza (Supervisor)
Abstract
The purpose of this study is to develop model predictive control approach to control a turbocompressor. The turbocompressor which is consisted of a gas turbine and a centrifugal compressor is manufactured for providing the necessary pressure for gas transport via the gas transmission network. The turbocompressor control system regulates the compressor outlet pressure by controlling the rotational speed of the gas turbine, while preventing the surge phenomenon in the compressor. Surge is a serious instability in the compressor that is associated with periodic fluctuations in system variables and can cause heavy damage to expensive machine parts.In this research, model predictive control has...
Design, Modeling and Control of Multi-Port Converters
, M.Sc. Thesis Sharif University of Technology ; Oraee Mirzamani, Hashem (Supervisor)
Abstract
Because of environmental problems of fossil fuel energies and the rise in petroleum products, the tendencies to the renewable sources like wind power and solar power have been increased. In some particular applications like electric vehicles, satellites power system and all stand-alone unites that are using solar and wind powers are the only solutions. On the other hand, because of intermittent behavior of renewable sources, use of back-up supplies e.g. batteries are necessary to make a balance in power consumptions and productions. To interface between different ports some independent two port converters are used in traditional techniques. Multiport converters, used in...
Control effectiveness investigation of a ducted-fan aerial vehicle using model predictive controller
, Article International Conference on Advanced Mechatronic Systems, ICAMechS ; 2014 , pp. 532-537 ; Emami, S. A ; Sharif University of Technology
Abstract
Special attention is given to vertical takeoff and landing air vehicles due to their unique capabilities and versatile missions. The main problem here is control effectiveness at low flight speeds and transition maneuvers because of the inherent instability. RMIT is a small sized tail-sitter ducted fan air vehicle with a particular configuration layout, multiple control surfaces, low weight, and high-speed flight capability. In the current study, a comprehensive nonlinear model is firstly developed for RMIT, followed by a validation process. This model consists of all parts including aerodynamic forces and moments, control surfaces term together with the gravity and driving fan forces....