Optimal trajectory tracking solution: Fractional order viewpoint     

Abolhassan Razminia  Mehdi Asadizadehshiraz  Hamid Reza Shaker 《Journal of The Franklin Institute》2019,356(3):1590-1603

In this paper, a generalized trajectory tracking problem for a closed-loop control system is formulated in the optimal control context. A linear time varying plant is considered to track a closed-loop desired trajectory generated by a given mechanism. The theoretical results are obtained based on the Hamilton-Jacobi-Bellman theory in which some generalized semiquadratic value functions are employed as the Lagrangian. In addition, we employ a non-integer order integral of Riemann-Liouville type as the cost functional, so that the trajectory tracking process can be evaluated in an extended optimum manner wherein the fractionality plays the main role. By selecting a suitable fractional order of the integral, a satisfactory optimal control system can be deduced in which least concentration on selecting the weighting matrices is needed. To show the effectiveness of the results, some numerical examples illustrate the potentials.  相似文献   

Anti-disturbance control based on disturbance observer for nonlinear systems with bounded disturbances     

Huifeng Zhang  Xinjiang Wei  Hamid Reza Karimi  Jian Han 《Journal of The Franklin Institute》2018,355(12):4916-4930

A composite anti-disturbance control problem for a class of nonlinear systems is studied in this paper. There are two types of disturbances in the systems, one is the matched disturbance with bounded variation rate, the other is the unmatched time-varying disturbances. A nonlinear disturbance observer is designed to estimate the matched disturbances, which can be presented separately from the controller design. By integrating DOBC with back-stepping method, a composite DOBC and back-stepping controller is proposed, and the disturbance estimations are introduced into the design of virtual control laws to compensate the unmatched disturbances. In addition, it is proved that all the states in the closed-loop system are uniformly ultimate bounded (UUB). Finally, a numerical example is given to demonstrate the feasibility and effectiveness of the proposed method.  相似文献   

New approaches to positive observer design for discrete-time positive linear systems     

Li-Juan Liu  Hamid Reza Karimi  Xudong Zhao 《Journal of The Franklin Institute》2018,355(10):4336-4350

This paper aims at providing new design approaches for positive observers of discrete-time positive linear systems based on a construction method of linear copositive Lyapunov function for positive systems. First, an efficient positive observer design approach is proposed by using linear programming such that the observer error system is exponentially stable. Furthermore, an interval observer design is proposed for uncertain positive systems. Then, the results are extended to positive time delay systems. In contrast with the previous design approaches, the new design method provides a general observer design with lower computational burden. Finally, three comparison examples are given to show the merit of the new design approach.  相似文献   

An examination of constructivist educational technologies: Key affordances and conditions     

Reza Feyzi Behnagh  Sepideh Yasrebi 《British journal of educational technology : journal of the Council for Educational Technology》2020,51(6):1907-1919

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A sliding mode approach to H∞ synchronization of master–slave time-delay systems with Markovian jumping parameters and nonlinear uncertainties     

Hamid Reza Karimi 《Journal of The Franklin Institute》2012,349(4):1480-1496

In this paper, a sliding-mode approach is proposed for exponential H_∞ synchronization problem of a class of master–slave time-delay systems with both discrete and distributed time-delays, norm-bounded nonlinear uncertainties and Markovian switching parameters. Using an appropriate Lyapunov–Krasovskii functional, some delay-dependent sufficient conditions and a synchronization law, which include the master–slave parameters are established for designing a delay-dependent mode-dependent sliding mode exponential H_∞ synchronization control law in terms of linear matrix inequalities. The controller guarantees the H_∞ synchronization of the two coupled master and slave systems regardless of their initial states. Two numerical examples are given to show the effectiveness of the method.  相似文献   

Development of a magnetic immunosorbent for on-chip preconcentration of amyloid �� isoforms: Representatives of Alzheimer��s disease biomarkers     

Zuzana Svobodova  Mohamad Reza Mohamadi  Barbora Jankovicova  Hermann Esselmann  Romain Verpillot  Markus Otto  Myriam Taverna  Jens Wiltfang  Jean-Louis Viovy  Zuzana Bilkova 《Biomicrofluidics》2012,6(2):024126-024126-12

Determination of amyloid β (Aβ) isoforms and in particular the proportion of the Aβ 1-42 isoform in cerebrospinal fluid (CSF) of patients suspected of Alzheimer’s disease might help in early diagnosis and treatment of that illness. Due to the low concentration of Aβ peptides in biological fluids, a preconcentration step prior to the detection step is often necessary. This study utilized on-chip immunoprecipitation, known as micro-immunoprecipitation (μIP). The technique uses an immunosorbent (IS) consisting of magnetic beads coated with specific anti-Aβ antibodies organized into an affinity microcolumn by a magnetic field. Our goal was to thoroughly describe the critical steps in developing the IS, such as selecting the proper beads and anti-Aβ antibodies, as well as optimizing the immobilization technique and μIP protocol. The latter includes selecting optimal elution conditions. Furthermore, we demonstrate the efficiency of anti-Aβ IS for μIP and specific capture of 5 Aβ peptides under optimized conditions using various subsequent analytical methods, including matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), capillary electrophoresis, microchip electrophoresis, and immunoblotting. Synthetic Aβ peptides samples prepared in buffer and spiked in human CSF were analyzed. Finally, on-chip immunoprecipitation of Aβ peptides in human CSF sample was performed.  相似文献   

Quasi-communities: rethinking learning in formal adult and vocational education     

Gholam Reza Emad  Wolff-Michael Roth 《Instructional Science》2016,44(6):583-600

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Characterization of low viscosity polymer solutions for microchip electrophoresis of non-denatured proteins on plastic chips     

Yasui T  Reza Mohamadi M  Kaji N  Okamoto Y  Tokeshi M  Baba Y 《Biomicrofluidics》2011,5(4):44114-441149

In this paper, we study characteristics of polymers (methylcellulose, hypromellose ((hydroxypropyl)methyl cellulose), poly(vinylpyrrolidone), and poly(vinyl alcohol)) with different chemical structures for microchip electrophoresis of non-denatured protein samples in a plastic microchip made of poly(methyl methacrylate) (PMMA). Coating efficiency of these polymers for controlling protein adsorption onto the channel surface of the plastic microchip, wettability of the PMMA surface, and electroosmotic flow in the PMMA microchannels in the presence of these polymers were compared. Also relative electrophoretic mobility of protein samples in solutions of these polymers was studied. We showed that when using low polymer concentrations (lower than the polymer entanglement point) where the sieving effect is substantially negligible, the interaction of the samples with the polymer affected the electrophoretic mobility of the samples. This effect can be used for achieving better resolution in microchip electrophoresis of protein samples.  相似文献   

A novel technique for optimal placement of piezoelectric actuators on smart structures   总被引：3，自引：0，他引：3  

Ali Reza Mehrabian  Aghil Yousefi-Koma 《Journal of The Franklin Institute》2011,348(1):12-23

The problem of positioning of actuators and sensors on smart materials has been a point of interest in recent years. This is due to the fact that in many practical applications there are limitations in space, weight, etc. of the smart structures, which make the problem of positioning more complex. In addition, it is required that the actuators/sensors have the best possible performance. The development of smart structures technology in recent years has provided numerous opportunities for vibration control applications. The use of piezoelectric ceramics or polymers has shown great promise in the development of this technology. The employment of piezoelectric material as actuators in vibration control is beneficial because these actuators only excite the elastic modes of the structures without exciting the rigid-body modes. This is important since very often only elastic motions of the structures are needed to be controlled. The purpose of this paper is to introduce a novel approach developed for optimizing the location of piezoelectric actuators for vibration suppression of flexible structures. A flexible fin with bonded piezoelectric actuators is considered in this study. The frequency response function (FRF) of the system is then recorded and maximization of the FRF peaks is considered as the objective function of the optimization algorithm to find the optimal placement of the piezoelectric actuators on the smart fin. Three multi-layer perceptron neural networks are employed to perform surface fitting to the discrete data generated by the finite element method (FEM). Invasive weed optimization (IWO), a novel numerical stochastic optimization algorithm, is then employed to maximize the weighted summation of FRF peaks. Results indicate an accurate surface fitting for the FRF peak data and an optimal placement of the piezoelectric actuators for vibration suppression is achieved.  相似文献   

Production and Purification of Rabbit’s Polyclonal Antibody Against Factor VIII     

Simin Sohrabi  Azim Akbarzadeh  Dariush Norouzian  Ali Farhangi  Mehri Mortazavi  Mohammad Reza Mehrabi  Mohsen Chiani  Zahra Saffari  Soheil Ghassemi 《Indian journal of clinical biochemistry : IJCB》2011,26(4):354-359

The attempt is made to produce recombinant factor VIII but the first step in producing such product is production and purification of rabbit’s polyclonal antibody against factor VIII. The second and third steps involve monoclonal antibody and recombinant factor VIII production. Factor VIII is one of the most important coagulating factor where its deficiency leads to diseases like hemophilia type A or classic. It is an inherited disease. Previously, it was obtained through fractionation of blood plasma of blood donors. After processing, factor VIII could be used to manage such patients. Due to transfer of viral disease like hepatitis and HIV through factor VIII obtained by fractionation, high cost of production, insufficiency of the donors and the process of virus removal, thus production of factor VIII through recombinant technology can be useful and helpful. The reaction between antibody and antigen is one the most specific reaction; therefore, such reaction can be employed to identify factor VIII. Thereby, rabbits were injected several times with adjuvant-linked antigen to produce antibody. The antibody was separated from the blood sample, purified and used to identify factor VIII in the research.  相似文献