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    Fault-Tolerant control of uncertain linear systems in the presence of L∞ disturbances and actuator saturation

    , Article 4th International Conference on Control, Instrumentation, and Automation, 27 January 2016 through 28 January 2016 ; 2016 , Pages 307-312 ; 9781467387040 (ISBN) Khatibi, M ; Haeri, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2016
    Abstract
    In this paper the fault-Tolerant control problem for uncertain linear systems in the presence of L, disturbances and actuator saturation is studied. The conflict between enlarging the domain of attraction and attenuating the effect of L, disturbances is tackled by proposing a non-constant state feedback controller. The feedback gains are calculated off-line by using linear matrix inequalities. In addition, the proposed method is capable of tolerating time-varying faults. The suggested approach is implemented on a sample model and the result is compared with other works  

    Fault Tolerant Control Considering Actuator Saturation and External Disturbances

    , Ph.D. Dissertation Sharif University of Technology Khatibi, Mahmood (Author) ; Haeri, Mohammad (Supervisor)
    Abstract
    A control system capable of tolerating system malfunctions while maintaining an acceptable level of performance is referred as fault tolerant control system. The constraints on the amplitude of input control signals limit the domain of attraction even for linear models. Ignoring this fact may lead to an unsatisfactory performance and even closed loop instability. Designing the controller such that the domain of attraction is maximized has been an attractive topic for researchers. On the other hand, persistent disturbances always play an essential role in the real word systems. Designing the controller in a way such that the effect of such disturbances is attenuated is another challenging... 

    Fault-tolerant control considering time-varying bounds on faults

    , Article Transactions of the Institute of Measurement and Control ; Volume 40, Issue 10 , 2018 , Pages 2982-2990 ; 01423312 (ISSN) Khatibi, M ; Haeri, M ; Sharif University of Technology
    SAGE Publications Ltd  2018
    Abstract
    This paper presents a novel fault-tolerant control strategy to compensate the time-varying loss of actuators’ effectiveness. It considers intermediate situations where the fault is not determined precisely (unlike active approaches) but overall estimations about its rate and final value are available through the previous experiences and/or experiments. Based on the estimations, two upper and lower time-varying bounds on the actuators’ effectiveness are established to be exploited in the procedure of controller design. In a special case, where these bounds are constant, the method will be reduced to the conventional passive approach. Also, actuator saturation and the effects of (Formula... 

    A unified framework for passive–active fault-tolerant control systems considering actuator saturation and L ∞ disturbances

    , Article International Journal of Control ; Volume 92, Issue 3 , 2019 , Pages 653-663 ; 00207179 (ISSN) Khatibi, M ; Haeri, M ; Sharif University of Technology
    Taylor and Francis Ltd  2019
    Abstract
    This paper presents a unified passive–active fault-tolerant control strategy to compensate the loss of actuators’ effectiveness. The proposed approach is capable of handling the system in pre- and post-fault diagnosis intervals by passive and active approaches, respectively. The stability of the designed system is independent of the accuracy of information provided by the fault detection and diagnosis unit, however, a precise estimation could improve the conservation. Actuator saturation and L ∞ disturbances effects are considered in the design stage. The trade-off between maximising the domain of attraction and minimising the effects of L ∞ disturbances is tackled by developing a... 

    A unified framework for passive–active fault-tolerant control systems considering actuator saturation and L∞ disturbances

    , Article International Journal of Control ; 2017 , Pages 1-11 ; 00207179 (ISSN) Khatibi, M ; Haeri, M ; Sharif University of Technology
    2017
    Abstract
    This paper presents a unified passive–active fault-tolerant control strategy to compensate the loss of actuators’ effectiveness. The proposed approach is capable of handling the system in pre- and post-fault diagnosis intervals by passive and active approaches, respectively. The stability of the designed system is independent of the accuracy of information provided by the fault detection and diagnosis unit, however, a precise estimation could improve the conservation. Actuator saturation and L∞ disturbances effects are considered in the design stage. The trade-off between maximising the domain of attraction and minimising the effects of L∞ disturbances is tackled by developing a non-constant... 

    Development of Regional Rainfall-Runoff Models

    , M.Sc. Thesis Sharif University of Technology Khatibi, Sahar (Author) ; Abrishamchi, Ahmad (Supervisor)
    Abstract
    Hydrological models are suitable tools for reduction of hydrological uncertainty in stream flow estimation. There are different historical approaches for the development of rainfall-runoff models, with regard to the choice of model structure and the calibration of the parameters, but the most attention has been focused on gauged catchments where sufficient data, in particular stream flow data, are available. So new modeling strategies for ungauged or pseudo ungauged catchments have been developed. This work was aimed to develop a methodology for the regionalization of some parameters of a conceptual rainfall-runoff model based on measurable physiographic, meteorological and even land... 

    Boundary-induced coherence in the staggered quantum walk on different topologies

    , Article Physical Review A ; Volume 98, Issue 1 , July , 2018 ; 24699926 (ISSN) Khatibi Moqadam, J ; Tayefeh Rezakhani, A ; Sharif University of Technology
    American Physical Society  2018
    Abstract
    The staggered quantum walk is a type of discrete-time quantum-walk model without a coin which can be generated on a graph using particular partitions of the graph nodes. We design Hamiltonians for potential realization of the staggered dynamics on a two-dimensional lattice composed of superconducting microwave resonators connected with tunable couplings. The naive generalization of the one-dimensional staggered dynamics generates two uncoupled one-dimensional quantum walks; thus more complex partitions need to be employed. However, by analyzing the coherence of the dynamics, we show that the quantumness of the evolution corresponding to two independent one-dimensional quantum walks can be... 

    Aerodynamic Optimization of Axial Transonic Compressor Blade by Adjoint Method Using Bump/ Local Blowing

    , Ph.D. Dissertation Sharif University of Technology Khatibi Rad, Saeedeh (Author) ; Mazaheri, Karim (Supervisor)
    Abstract
    Transonic flow compressors are widely used today. In these systems, the occurrence of shock waves, interaction of the shock and the boundary layer, thickening of the boundary layer and separation are some challenges which can severely affect the aerodynamic performance. Here we use a numerical analysis and an optimization algorithm to optimize the aerodynamic shape of a transonic axial compressor blade section. The total pressure loss through a cascade of blade sections is selected as the cost function. A continuous adjoint optimization method is used along with a RANS solver to find the new blade section shape. Application of three different geometric modelling of a compressor blade section... 

    Biodiesel production via transesterification of canola oil in the presence of Na–K doped CaO derived from calcined eggshell

    , Article Renewable Energy ; Volume 163 , 2021 , Pages 1626-1636 ; 09601481 (ISSN) Khatibi, M ; Khorasheh, F ; Larimi, A ; Sharif University of Technology
    Elsevier Ltd  2021
    Abstract
    CaO derived from calcined eggshell was doped with Na–K by wet impregnation method and the effect of different Na/K molar ratios was investigated on biodiesel production from canola oil. The catalysts were characterized by X-ray Powder Diffraction (XRD), Brunauer–Emmett–Teller (BET), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), and Thermogravimetric (TGA) analyses. FAME yields were determined by Gas Chromatography-Mass Spectrometry (GC-MS). The Na–K/CaO catalyst with Na/K molar ratio of 1 showed the highest FAME yield of 97.6% at optimum reaction conditions. Structural investigation of materials revealed that FAME yield was proportional to the number of basic sites on... 

    Mimicking the Hadamard discrete-time quantum walk with a time-independent Hamiltonian

    , Article Quantum Information Processing ; Volume 18, Issue 5 , 2019 ; 15700755 (ISSN) Khatibi Moqadam, J ; de Oliveira, M. C ; Sharif University of Technology
    Springer New York LLC  2019
    Abstract
    The discrete-time quantum walk dynamics can be generated by a time-dependent Hamiltonian, repeatedly switching between the coin and the shift generators. We change the model and consider the case where the Hamiltonian is time-independent, including both the coin and the shift terms in all times. The eigenvalues and the related Bloch vectors for the time-independent Hamiltonian are then compared with the corresponding quantities for the effective Hamiltonian generating the quantum walk dynamics. Restricted to the non-localized initial quantum walk states, we optimize the parameters in the time-independent Hamiltonian such that it generates a dynamics similar to the Hadamard quantum walk. We... 

    3d Design of a Microfluidic Chip for Anticancer Drugs Screening

    , M.Sc. Thesis Sharif University of Technology Hashemi, Maryam Sadat (Author) ; Mashayekhan, Shohreh (Supervisor) ; Saadatmand, Maryam (Supervisor)
    Abstract
    Nowadays, advanced and inexpensive pre-clinical methods for investigating the effects of anti-cancer drugs are expanding. One of the latest three-dimensional laboratory modeling for evaluating the effects of drugs is the use of tumor-on-chip technology, which actually models the physiological system of the body through three-dimensional scaffolds, multicellular cultures, and shaped vascular systems. In this study, three-dimensional culture of cancer cells was performed in the form of spheroids. A chip of U-shaped microstructures with and without gaps was used to trap cells and form cancer spheroids. We simulated the simultaneous effect of drug and oxygen concentration distribution inside the... 

    Production of Biodiesel Using Eggshell as Catalyst

    , M.Sc. Thesis Sharif University of Technology Khatibi, Maryam (Author) ; Khorasheh, Farhad (Supervisor) ; Larimi, Afsaneh Sadat (Supervisor)
    Abstract
    The aim of this project is to investigate and synthesize CaO-based nanocatalysts derived from chicken eggshell calcination with alkali metals and sodium-potassium compounds promoters used in the transesterification reaction of canola oil and methanol. Sections of this thesis include the synthesis of nanocatalysts, catalyst characterization tests, and investigation of reaction under optimal conditions. Two groups of catalysts containing different weight percentages of alkali metals based on CaO and 1 %wt sodium-potassium based on CaO with different weight percentages of these two elements were synthesized by wet impregnation method and used in the reaction under optimum condition. Catalyst... 

    Model Checking of Stochastic Activity Networks

    , M.Sc. Thesis Sharif University of Technology Maryam Bagheri (Author) ; Movaghar, Ali (Supervisor)
    Abstract
    Modeling and performance evaluation of the real time distributed systems is a significant problem. Stochastic activity network is one of the high level models used for this purpose. This network is an extension of generalized stochastic Petri net which is more powerful and flexible than other Petri net extensions. Checking the satisfiability of properties such as performance, dependability and user's expected properties is considerable in these models. Thus, using the approaches and generating modeling and model checking tools with the mentioned purpose is attractive. A model checker automatically checks the correctness of the system behaviors as properties against the model by getting the... 

    Fabrication of Thick Scaffold with Microfluidic Channels by Bioprinter

    , M.Sc. Thesis Sharif University of Technology Khalighi, Sadaf (Author) ; Saadatmand, Maryam (Supervisor)
    Abstract
    Cardiovascular diseases are among the leading causes of death worldwide. For instance, in 2015, almost 31% of the world’s mortality rate was due to these causes. One of these diseases is cardiac coronary vessels’ occlusion which leads to the insufficient blood supply to the heart tissue and cardiomyocytes death after Myocardial Infarction (MI). After MI, a hierarchy of events in the heart tissue changes heart muscle and forms cardiac fibrosis. This fibrotic tissue does not have the native one’s properties and function, so it will cause cardiac arrest and patient death. Therefore, it is obvious that vascular network plays a crucial role in the heart function. The importance of cardiac... 

    Robust Estimation and Control of a Planet Lander

    , M.Sc. Thesis Sharif University of Technology Ahmadvand, Reza (Author) ; Kiani, Maryam (Supervisor)
    Abstract
    This study has focused on the important problem of landing on a planet as an important current and future space mission. In this regard, dynamics modeling and integrated state estimation and control problems have been investigated in different views. To this aim, first a novel concurrent representation for translational and rotational kinematics has been developed based on the extension of modified Rodrigues parameters to dual space. This parameter set, called dual modified Rodrigues parameters (DMRP), is then utilized to establish an integrated roto-translational dynamic. The proposed DMRP-based kinematics and dynamics have been verified via comparison to traditional methods of... 

    Optimal Control of Unknown Interconnected Systems via Distributed Learning

    , M.Sc. Thesis Sharif University of Technology Farjadnasab, Milad (Author) ; Babazadeh, Maryam (Supervisor)
    Abstract
    This thesis addresses the problem of optimal distributed control of unknown interconnected systems. In order to deal with this problem, a data-driven learning framework for finding the optimal centralized and the suboptimal distributed controllers has been developed via convex optimization.First of all, the linear quadratic regulation (LQR) problem is formulated into a nonconvex optimization problem. Using Lagrangian duality theories, a semidefinite program is then developed that requires information about the system dynamics. It is shown that the optimal solution to this problem is independent of the initial conditions and represents the Q-function, an important concept in reinforcement... 

    Utilizing Gaussian Processes to Learn Dynamics of Unknown Torques Acting on a Spacecraft

    , M.Sc. Thesis Sharif University of Technology Baradaran, Behdad (Author) ; Kiani, Maryam (Supervisor)
    Abstract
    Accurate and fast attitude estimation of a rigid body plays an essential role in the performance of a vehicle’s control system, especially aerospace vehicles. Ample works have been done to increase the accuracy and speed of the attitude estimation process, but all have been developed according to a model-based approach. This approach assumes that the torques acting on the body have a known dynamical model that is used for the attitude estimation. The purpose of the present research is to estimate the attitude via a model-free approach, i. e. dynamics of the torques acting on the body are no longer assumed to be known, and its learning is the next step. Thus, the problem formulation of this... 

    Stabilization and Pole-Placement by Structurally-Constrained Controllers: A Graph-Theoretic Approach

    , M.Sc. Thesis Sharif University of Technology Moushaee, Pegah (Author) ; Babazadeh, Maryam (Supervisor)
    Abstract
    This thesis presents a new approach to design structural output feedback controllers with stabilization and pole-placement at desired points on the S plane. It is assumed that the linear time-invariant system has no fixed mode corresponding to the specified control structure, outside the desired region of the closed-loop poles, such that the structural controller design problem is theoretically feasible. To this end, the structural output controller design problem is first transformed into a structurally equivalent problem based on the solution of a set of discrete linear programs. Then, by using the resultant structure, a new method is proposed for designing static and dynamic control loops... 

    Fabrication the Hydrogel Microfibers Using Bioprinter with Application in Cardiovascular Model

    , M.Sc. Thesis Sharif University of Technology Heidari, Faranak (Author) ; Saadatmand, Maryam (Supervisor)
    Abstract
    Cardiovascular disease (CVD) currently remains a considerable challenge for clinical treatments. CVDs account for N17.5 million deaths per year and will predictably increase to 23.6 million by 2030. The main purpose is to create human model systems to study the effect of disease mutations or drug treatment on the heart. In addition, engineered cardiac tissues are considered promising candidates to be transplanted to improve the function of diseased hearts. For engineered active tissues/organs, 3D bioprinting can fabricate complex tissue architecture with a spatiotemporal distribution of bioactive substances (cells, growth factors, and others) to better guide tissue regeneration. However,... 

    Design of Microfluidic Chip for 3D Cell Culture

    , M.Sc. Thesis Sharif University of Technology Ghobadi, Faezeh (Author) ; Saadatmand, Maryam (Supervisor)
    Abstract
    Understanding biological systems requires extensive knowledge of individual parameters, and to study the processes of cell differentiation and cell behavior, a suitable environment must be created with the physiological conditions of the human body. For this purpose, with the knowledge of microfluidics, a microenvironment can be provided to study the behavior of cells on a small scale. The use of bone tissue model microfluidic chips is an alternative and new method in which it is possible to study the behavior of cells to differentiate into bone and to examine the toxicity of drugs, which in itself can help in the effective and successful treatment of these cases show. Therefore, in this...