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Yu X.,Nanjing Southeast University | Xie X.-J.,Qufu Normal University
IEEE Transactions on Automatic Control | Year: 2010

This paper develops a unifying framework for output feedback regulation of stochastic nonlinear systems with more general stochastic inverse dynamics. The contributions of this work are characterized by the following novel features: 1) Motivated by the concept of integral input-to-state stability (iISS) in deterministic systems and stochastic input-to-state stability (SISS) using Lyapunov function in stochastic systems, a concept of stochastic integral input-to-state stability (SiISS) using Lyapunov function is first introduced, two important properties of SiISS are obtained: (i) SiISS is strictly weaker than SISS using Lyapunov function; (ii) SiISS is stronger than the minimum-phase property. However, only under the minimum-phase assumption, there is no dynamic output feedback control law for global stabilization in probability. 2) Almost sure boundedness, a reasonable and stronger concept than boundedness in probability, is introduced. The purpose of introducing the concept is to prove the boundedness and convergence of some signals in the closed-loop control system. 3) Some important mathematical tools which play an essential role in the boundedness and convergence analysis of the closed-loop system are established. 4) A unifying framework is proposed to design a dynamic output feedback control law, which drives the states to the origin almost surely while maintaining all the closed-loop signals bounded almost surely. © 2010 IEEE.


Xu Y.,Qufu Normal University
Computers and Industrial Engineering | Year: 2011

In this paper, a new approach is proposed to solve group decision making (GDM) problems where the preference information on alternatives provided by decision makers (DMs) is represented in four formats of incomplete preference relations, i.e.; incomplete multiplicative preference relations, incomplete fuzzy preference relations, incomplete additive linguistic preference relations, incomplete multiplicative linguistic preference relations. In order to make the collective opinion close each decision maker's opinion as near as possible, an optimization model is constructed to integrate the four different formats of incomplete preference relations and to compute the collective ranking values of the alternatives. The ranking of alternatives or selection of the most desirable alternative(s) is directly obtained from the derived collective ranking values. A numerical example is also used to illustrate the applicability of the proposed approach. © 2011 Elsevier Ltd. All rights reserved.


Xie X.-J.,Qufu Normal University | Liu L.,Qufu Normal University
Automatica | Year: 2012

This article further discusses the output feedback stabilization problem for stochastic high-order nonlinear systems with time-varying delay. Under the weaker conditions on nonlinearities in drift and diffusion vector fields, by using the idea of homogeneous domination approach, skillfully choosing an appropriate LyapunovKrasoviskii functional, and successfully solving several troublesome obstacles in the design and analysis procedure, an output feedback controller is constructed to render the closed-loop system globally asymptotically stable in probability. © 2012 Elsevier Ltd. All rights reserved.


Ma C.-Q.,Qufu Normal University | Zhang J.-F.,CAS Academy of Mathematics and Systems Science
IEEE Transactions on Automatic Control | Year: 2010

Consensusability of multi-agent systems (MASs) is a fundamental problem in the MAS research area, since when starting to design a consensus protocol, one should know whether or not there exists such a protocol that has the ability to make the MAS involved consensus. This technical note is aimed at studying the joint impact of the agent dynamic structure and the communication topology on consensusability. For the MASs with fixed topology and agents described by linear time-invariant systems, a necessary condition of consensusability with respect to a set of admissible consensus protocols is given, which is shown, under some mild conditions, to be necessary and sufficient. © 2010 IEEE.


A facile and fast microwave-assisted ionic liquid method has been developed to prepare PtRu nanoparticles onto multi-walled carbon nanotubes (MWCNTs). This novel method has some advantages, such as the high electrocatalytic activity of the catalysts for the methanol oxidation, simple preparation procedures, and recycle of the ionic liquids. Transmission electron micrograph shows that PtRu nanoparticles with diameter of 2-5 nm are uniformly deposited along the length of the MWCNTs (PtRu/MWCNTs). The structure and nature of the resulting PtRu/MWCNT catalysts are also characterized by X-ray diffraction. Electrochemical measurements show that the electrocatalytic oxidation of methanol shows very high catalytic efficiency compared with commercial E-TEK Pt/C (20 wt%Pt) catalysts, which is crucial for anode electrocatalysis in direct methanol fuel cells. © 2010 Elsevier B.V.


With anodized titanium in fluoride-containing perchloric acid solution as an example in the present Article, the physical origin of the faradaic pseudocapacitance C 0 frequently observed in electrochemical impedance spectroscopy (EIS) spectra at low frequencies was interpreted for the first time by the incorporation/insertion of some electrolyte anions (i.e., F-ions in this work) into the oxide film under the electric field during film growth. It was shown that the emergence of the faradaic pseudocapacitive behavior not only indicates a significant incorporation of anions into the oxide films but also reflects the arrival of them at the metal/oxide interface. The anion incorporation/transfer process was depicted with a modified point-defect model and simulated by a blocking, restricted finite-length diffusion impedance model (which has been widely used for studying the ion-insertion electrodes). The fast inward migration of the incorporated electrolyte species, along with the accumulation of them at the metal/film interface (due to the blocking effect of this interface), is responsible for the low-frequency capacitance behavior revealed by a vertical capacitive line in EIS spectra at low frequencies for anodically growing oxide films on valve metals. Many related published results for anodized valve metals (such as Ti, Bi, Ta, Al, etc.) are in good accordance with the model predictions. This work also suggests that the electrochemical method for the preparation of F --doped TiO 2 thin film materials should be an easy, low-cost, and even more effective one to be used. © 2010 American Chemical Society.


We synthesize the new Pt based catalyst for direct ethanol fuel cells using novel multi-walled carbon nanotubes supported platinum-antimony tin oxide (Pt-ATO/MWCNT) nanoparticle as new catalyst support for the first time. The structure of Pt-ATO/MWCNT catalyst is characterized by transmission electron micrograph (TEM) and X-ray diffraction (XRD). The electrocatalytic properties of Pt-ATO/MWCNT catalyst for ethanol electrooxidation reactions are investigated by cyclic voltammetry (CV) and chronoamperometric experiments in acidic medium. The electrocatalytic activity for ethanol electrooxidation reaction shows that high carbon monoxide tolerance and good stability of Pt-ATO/MWCNT catalyst compared with Pt-SnO 2/MWCNT and commercial Pt/C are observed. These results imply that Pt-ATO/MWCNT catalyst has promising potential applications in direct alcohol fuel cells. © 2010 Elsevier B.V.


Liu L.,Qufu Normal University | Xie X.-J.,Qufu Normal University
Automatica | Year: 2011

This paper investigates output-feedback control for a class of stochastic high-order nonlinear systems with time-varying delay for the first time. By introducing the adding a power integrator technique in the stochastic systems and a rescaling transformation, and choosing an appropriate Lyapunov-Krasoviskii functional, an output-feedback controller is constructed to render the closed-loop system globally asymptotically stable in probability and the output can be regulated to the origin almost surely. A simulation example is provided to show the effectiveness of the designed controller. © 2011 Elsevier Ltd. All rights reserved.


Li G.,Qufu Normal University | Wang W.,University of Bonn
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2014

In this paper, we study radiative decays of X b, the counterpart of the famous X(3872) in the bottomonium-sector as a candidate for meson-meson molecule, into the γΥ{hooked}(n S) (n = 1, 2, 3). Since it is likely that the X b is below the BB-* threshold and the mass difference between the neutral and charged bottom meson is small compared to the binding energy of the X b, the isospin violating decay mode X b→Υ{hooked}(n S)π +π - would be greatly suppressed. This will promote the importance of the radiative decays. We use the effective Lagrangian based on the heavy quark symmetry to explore the rescattering mechanism and calculate the partial widths. Our results show that the partial widths into γΥ{hooked}(n S) are about 1 keV, and thus the branching fractions may be sizeable, considering the fact the total width may also be smaller than a few MeV like the X(3872). These radiative decay modes are of great importance in the experimental search for the X b particularly at hadron collider. An observation of the X b will provide a deeper insight into the exotic hadron spectroscopy and is helpful to unravel the nature of the states connected by the heavy quark symmetry. © 2014 The Authors.


Xie X.-J.,Qufu Normal University | Liu L.,Qufu Normal University
IEEE Transactions on Automatic Control | Year: 2013

The homogeneous domination approach is introduced to solve the state feedback stabilization problem for stochastic high-order nonlinear systems with time-varying delay. Under the weaker conditions on the drift and diffusion terms, by using the homogeneous domination approach and solving several troublesome obstacles in the design and analysis procedure, a state feedback controller is constructed to render the closed-loop system globally asymptotically stable in probability. © 2012 IEEE.

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