This paper considers the problem of robust mixed H 2/H ∞ delayed state feedback control for a class of uncertain neutral systems with time-varying discrete and distributed delays. Based on the Lyapunov-Krasovskii functional theory, new required sufficient conditions are established in terms of delay-range-dependent linear matrix inequalities (LMIs) for the stability and stabilization of the considered system using some free matrices. The desired robust mixed H 2/H ∞ delayed control is derived based on a convex optimization method such that the resulting closed-loop system is asymptotically stable and satisfies H 2 performance with a guaranteed cost and a prescribed level of H ∞ performance, simultaneously. Finally, a numerical example is given to illustrate the effectiveness of our approach.
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In this paper, a control strategy to reduce the vibrational response of adjacent buildings under seismic excitation is presented. The proposed strategy combines passive linking elements with an active decentralized control system. The overall active-passive control system admits decentralized design and operation, and achieves an excellent vibrational reduction when the active control system works; in case of a full or partial failure of the active control system, a remarkable reduction in the vibrational response is guaranteed by the passive linking elements. For adjacent buildings that require different levels of seismic protection, the implementation of an active H ∞ control system in just one of the buildings is also considered. The main ideas are presented by means of a simplified two-building model. Numerical simulations have been carried out to assess the performance of the proposed methodology with promising results.
There are various real-world applications such as video ads, airport screenings, courtroom trials, and job interviews where deception detection can play a crucial role. Hence, there are immense demands on deception detection in videos. Videos contain rich information including acoustic, visual, temporal, and/or linguistic information, which provides great opportunities for advanced deception detection. However, videos are inherently complex; moreover, they lack detective labels in many real-world applications, which poses tremendous challenges to traditional deception detection. In this manuscript, I present my Ph.D. research on the problem of deception detection in videos. In particular, I provide a principled way to capture rich information into a coherent model and propose an end-to-end framework DEV to detect DEceptive Videos automatically. Preliminary results on real-world videos demonstrate the effectiveness of the proposed framework.
In this paper, we contribute to the further development of delay-range-dependent state-feedback aspect of robust control for vibration reduction in a building structure with limited wireless communication capacity subjected to measurement quantization, signal transmission delay and data packet dropout, which appear typically in a network environment. The feedback loop is subjected to a time-varying bounded delay within the sensors and the structure. By using an appropriate Lyapunov-Krasovskii functional and some free weighting matrices, new sufficient conditions in terms of some linear matrix inequalities are established for the existence of desired controllers such that the resulting closed-loop system is asymptotically stable and kept within a prescribed level of H1 performance bound. Finally, simulation results are given to illustrate the usefulness of the proposed control methodology.
In this paper a practical modelling methodology is presented for a series of aero- servo- elastic- coupled numerical analyses of small wind turbine operation, with particular emphasis on variable speed generator modelling in various wind speed conditions. The following characteristics are determined using the available computer tools: the tip speed ratio as a function of the generator constant (under the assumption of constant wind speed), the turbine coefficient of power as a function of the tip speed ratio (the torque curve is modified accordingly and generator speed and power curves are plotted), turbine power curves and coefficient of power curve as functions of the incoming wind speed. The last stage is to determine forces and torques acting on rotor blades and turbine tower for specific incoming wind speeds in order to examine the impact of the stall phenomena on these values (beyond the rated power of the turbine). It is shown that the obtained results demonstrate a valuable guideline for small wind turbines design process.
In this paper, an approach for designing an adaptive fuzzy model predictive control (AFMPC) based on the Ant Colony Optimization (ACO) is studied. On-line adaptive fuzzy identification is used to identify the system parameters. These parameters are used to calculate the objective function based on predictive approach and structure of RST control. The optimization problem is solved based on an ACO algorithm, used at the optimization process in AFMPC to calculate a sequence of future RST control actions. The obtained simulation results show that proposed approach provides better results compared with Proportional Integral-Ant Colony Optimization (PI-ACO) controller and adaptive fuzzy model predictive control (AFMPC).
Focusing on the amplifier performance evaluation demand, a novel evaluation strategy based on<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mrow><mml:mi>δ</mml:mi></mml:mrow></mml:math>-support vector regression (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mrow><mml:mi>δ</mml:mi></mml:mrow></mml:math>-SVR) is proposed in this paper. Lower computer calculation demand is considered firstly. And this is dealt with by the superiority of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mrow><mml:mi>δ</mml:mi></mml:mrow></mml:math>-SVR which can be significantly improved on the number of support vectors. Moreover, the function of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M4"><mml:mrow><mml:mi>δ</mml:mi></mml:mrow></mml:math>-SVR employs the modified RBF kernel function which is constructed from an original kernel by removing the last coordinate and adding the linear term with the last coordinate. Experiment adopted the typical circuit Sallen-Key low pass filter to prove the proposed evaluation strategy via the eight performance indexes. Simulation results reveal that the need of the number of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M5"><mml:mrow><mml:mi>δ</mml:mi></mml:mrow></mml:math>-SVR support vectors is the lowest among the other two methods LSSVR and ε -SVR under obtaining nearly the same evaluation result. And this is also suitable for promotion computational speed.
In this paper, we investigate the stability problem for some Markovian switching reaction–diffusion coupled systems on networks (MSRDCSNs). By using the Lyapunov function, we establish some novel stability principles for stochastic stability, asymptotically stochastic stability, globally asymptotically stochastic stability and almost surely exponential stability of the MSRDCSNs. These stability principles have a close relation to the topology property of the network. We also provide a systematic method for constructing global Lyapunov function for these MSRDCSNs by using graph theory. The new method can help analyze the dynamics of complex networks.
Learning-
This study focuses on stochastic stability and H ∞ control of two-dimensional (2-D) continuous delayed Markovian jump systems (MJSs) with partial information on transition probability. At first, a sufficient condition for the stochastic stability of 2-D MJSs is proposed by choosing an appropriate Lyapunov–Krasovskii functional. Then, the results are developed by designing a state feedback controller that guarantees the stochastic stability of the resultant closed-loop system with a prescribed H ∞ performance level γ. Finally, the proposed results are validated with the help of examples.
