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Baocang Ding - One of the best experts on this subject based on the ideXlab platform.

  • homogeneous polynomially nonquadratic stabilization of discrete time takagi sugeno systems via nonparallel distributed Compensation Law
    IEEE Transactions on Fuzzy Systems, 2010
    Co-Authors: Baocang Ding
    Abstract:

    This paper considers stability of discrete-time nonlinear systems in Takagi-Sugeno (T-S) form. This problem has been studied for more than 20 years with many sufficient conditions, and the asymptotically necessary and sufficient (ANS) conditions with respect to the common-quadratic Lyapunov, function, having being obtained. This paper considers general forms of homogeneous polynomially nonquadratic Lyapunov (HPNQL) function and homogeneous polynomially parameterized nonparallel distributed Compensation (HPP-non-PDC) Law. By generalization of the procedure based on Polya's theorem and techniques used for parameter-dependent linear matrix inequality (PD-LMI) which have been studied previously in different contexts, ANS stability conditions with respect to the general HPNQL function are obtained.

  • stabilization of takagi sugeno model via non parallel distributed Compensation Law
    World Congress on Intelligent Control and Automation, 2008
    Co-Authors: Baocang Ding, Biao Huang
    Abstract:

    This paper addresses the stabilization of nonlinear systems, which is represented by a Takagi-Sugeno (T-S) model. Based on the extended nonquadratic Lyapunov function and the nonparallel distributed Compensation Law, three new results are obtained by using appropriate slack matrices, collection matrices, and the higher dimensional collection matrix. The first two results are less conservative, and computationally less expensive, than some of the existing results. The third result combines the procedures of the first two results, and is less conservative, but is computationally more expensive than the first two results. The effectiveness of the new results is validated by two numerical examples.

Howard M Branz - One of the best experts on this subject based on the ideXlab platform.

  • origin and consequences of the Compensation meyer neldel Law
    Physical Review B, 1992
    Co-Authors: A Yelon, B Movaghar, Howard M Branz
    Abstract:

    We have recently demonstrated that the Meyer-Neldel (MN) rule (Compensation Law) may be understood as arising naturally when the activation energy for a process is significantly larger than both the typical excitations available and kT. This conclusion was supported by the results of two microscopic models, related to special cases. In the present paper we present arguments, based on general results from statistical physics, which lead to the same conclusion. We show that this simple explanation also leads to the solution of a number of puzzles which have been associated with Meyer-Neldel behavior

  • origin and consequences of the Compensation meyer neldel Law
    Physical Review B, 1992
    Co-Authors: A Yelon, B Movaghar, Howard M Branz
    Abstract:

    We have recently demonstrated that the Meyer-Neldel (MN) rule (Compensation Law) may be understood as arising naturally when the activation energy for a process is significantly larger than both the typical excitations available and kT. This conclusion was supported by the results of two microscopic models, related to special cases. In the present paper we present arguments, based on general results from statistical physics, which lead to the same conclusion. We show that this simple explanation also leads to the solution of a number of puzzles which have been associated with Meyer-Neldel behavior. We show that phenomena in groups of similar materials yield similar MN slopes. Finally, we show that the values of the slope for semiconductors with gaps in the 1--2-eV range are consistent with the suggestion that optical phonons are the source of the excitation energy in such processes.

Baohua Zhang - One of the best experts on this subject based on the ideXlab platform.

  • calculation of oxygen self diffusion coefficients in mg2sio4 polymorphs and mgsio3 perovskite based on the Compensation Law
    Solid State Ionics, 2011
    Co-Authors: Baohua Zhang, Rulong Zhou
    Abstract:

    Abstract Without using any adjustable parameter, the temperature and pressure dependences of oxygen self-diffusion coefficients in Mg 2 SiO 4 polymorphs (forsterite, wadsleyite and ringwoodite) and MgSiO 3 perovskite have been successfully reproduced from the cBΩ model that interconnects point defect parameters with bulk properties under the corresponding P – T conditions of the lower mantle. In addition, an alternative method is proposed to calculate the pre-exponential factor of oxygen diffusion coefficients from the measurements of the electrical conductivity through the Nernst–Einstein equation, which is based on an observed Compensation Law between activation energies and pre-exponential factors for the electrical conductivity of forsterite and MgSiO 3 perovskite. In most cases, our results show the cBΩ model does better than the latter approach, and the self-diffusion coefficients values derived from the cBΩ model agree fairly well with the experimental ones if the relevant uncertainties are considered. Furthermore, the cBΩ model is also found to give a correct estimation of the activation enthalpy and volume for MgSiO 3 perovskite. However, the calculated activation enthalpies and activation volumes of O diffusion in Mg 2 SiO 4 polymorphs are shown to differ substantially between our empirical estimates and the theoretical calculations.

Alan G. Jones - One of the best experts on this subject based on the ideXlab platform.

  • Compensation of the Meyer-Neldel Compensation Law for H diffusion in minerals
    Geochemistry Geophysics Geosystems, 2014
    Co-Authors: Alan G. Jones
    Abstract:

    The Meyer-Neldel Rule (MNR), or Compensation Law, linearly relates the preexponent term to the logarithm of the excitation enthalpy for any process that is thermally driven in an Arrhenian manner, and MNR fits can be used to calibrate and validate laboratory experimental results. Both robust least squares linear regressions and nonrobust regressions on selected subsets for individual minerals with sufficient experimental data demonstrate that hydrogen diffusion in minerals obeys the MNR with differing MNR intercepts and gradients depending on the mineral. In particular, nominally anhydrous mantle minerals have very distinct and different MNR parameters compared to hydrous and crustal minerals, with garnet proving to be an outlier lying in between the two. Furthermore, the variations of the estimated intercepts and gradients of the various MNRs are not random, but remarkably they themselves fall on a striking linear trend. This observation, if more broadly true, has profound implications for materials sciences and understanding of solid-state physics, as it implies that the Compensation rule is itself compensated.

A. Kumar - One of the best experts on this subject based on the ideXlab platform.