Time filter

Source Type

Jinzhou, China

Bohai University established in 1950, is a university in Jinzhou, Liaoning province, northeast China. Wikipedia.

Li H.,Bohai University | Jing X.,Hong Kong Polytechnic University | Karimi H.R.,University of Agder
IEEE Transactions on Industrial Electronics | Year: 2014

This paper deals with the problem of output-feedback H∞ control for a class of active quarter-car suspension systems with control delay. The dynamic system of the suspension systems is first formed in terms of the control objectives, i.e., ride comfort, road holding, suspension deflection, and maximum actuator control force. Then, the objective is to the design of the dynamic output-feedback H∞ controller in order to ensure asymptotic stability of the closed-loop system with H∞ disturbance attenuation level and the output constraints. Furthermore, using Lyapnov theory and linear matrix inequality (LMI) approach, the existence of admissible controllers is formulated in terms of LMIs. With these satisfied conditions, a desired dynamic output-feedback controller can be readily constructed. Finally, a quarter-vehicle model is exploited to demonstrate the effectiveness of the proposed method. © 1982-2012 IEEE. Source

Wu J.-P.,Bohai University
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2013

We investigate the low energy behaviors around the Fermi surface at the non-relativistic fixed points and give some clear and direct numerical results on the structure of the Fermi surface in the presence of a holographic flat band. Compared with the case of the dual relativistic fermionic system, the Fermi momentum is suppressed by the presence of the holographic flat band. In particular, we give an analytical understanding of the low energy behaviors of the dual non-relativistic fermionic system. One finds that due to AdS2×R2 background geometry in the near horizon limit, the scaling behaviors of the spectral function at the non-relativistic fixed points is as same as that at the relativistic fixed points, which controlled by the IR Green's function GI(k,ω). As a check, we also give a comparison about the scaling exponents δ of the dispersion relation between the numerical and analytical results. One finds that the numerical result is agree well with the analytical that. © 2013 Elsevier B.V. Source

Wu J.-P.,Bohai University
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2014

We study the fermionic response including the bulk dipole coupling on the charged Lifshitz black brane from Einstein-Dilaton-Maxwell model. For fixed Lifshitz dynamical critical exponent z, by tuning the dipole coupling parameter p, we can realize the phase transitions from Fermi liquid, to marginal Fermi liquid, to non-Fermi liquid and finally to Mott insulator. The Lifshitz dynamical critical exponent z plays the role of making the phase transition point from Fermi liquid to non-Fermi liquid or to Mott insulator decrease with the increase of z for fixed dipole coupling p. © 2013 The Author. Source

Li X.,Harbin Institute of Technology | Gao H.,Bohai University
Automatica | Year: 2013

This paper is concerned with the problem of robust finite frequency (FF) H∞ filtering for uncertain twodimensional (2-D) discrete-time systems in the Fornasini-Marchesini local state-space (FM LSS) model with polytopic uncertain parameters. The goal of the paper is to design filters such that the FF H∞ norm of the filtering error system has a specified upper bound for all uncertainties. In light of a recently developed generalized bounded real lemma, a linear matrix inequality-based approach is proposed for robust FF H∞ filter analysis and design. It is demonstrated that the presented approach to robust FF H∞ filter design covers the latest standard H∞ filtering result. Moreover, it is shown that the existing results specialized for the Roesser model, when applied to the FM LSS model through a model transformation, are much more restrictive than the proposed results in the paper, further justifying this work. © 2013 Elsevier Ltd. All rights reserved. Source

Chang X.-H.,Bohai University
IEEE Transactions on Fuzzy Systems | Year: 2012

This paper is concerned with the H∞ filtering problem for continuous-time Takagi-Sugeno (T-S) fuzzy systems. Different from existing results for fuzzy H∞ filtering, the proposed ones are toward uncertain fuzzy systems with linear fractional parametric uncertainties. Attention is focused on the design of a fuzzy filter such that the filtering error system preserves a prescribed H∞ performance, where the filter to be designed is assumed to have gain variations. By a descriptor representation approach, two sufficient conditions for the H∞ filter design are proposed in terms of linear matrix inequalities (LMIs). When these LMIs are feasible, an explicit expression of the desired filter is given. A simulation example will be given to show the efficiency of the proposed methods. © 2012 IEEE. Source

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