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Probability-dependent gain-scheduled filtering for stochastic systems with missing measurements
Copyright @ 2011 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.This brief addresses the gain-scheduled filtering problem for a class of discrete-time systems with missing measurements, nonlinear disturbances, and external stochastic noise. The missing-measurement phenomenon is assumed to occur in a random way, and the missing probability is time-varying with securable upper and lower bounds that can be measured in real time. The multiplicative noise is a state-dependent scalar Gaussian white-noise sequence with known variance. The addressed gain-scheduled filtering problem is concerned with the design of a filter such that, for the admissible random missing measurements, nonlinear parameters, and external noise disturbances, the error dynamics is exponentially mean-square stable. The desired filter is equipped with time-varying gains based primarily on the time-varying missing probability and is therefore less conservative than the traditional filter with fixed gains. It is shown that the filter parameters can be derived in terms of the measurable probability via the semidefinite program method.This work was supported in part by the Leverhulme Trust of the U.K., the Engineering and Physical Sciences Research Council (EPSRC) of the U.K. under Grant GR/S27658/01, the National Natural Science Foundation of China under Grants 61028008, 61074016 and 60974030, the Shanghai Natural
Science Foundation of China under Grant 10ZR1421200, and the Alexander von Humboldt Foundation of Germany
Probing the momentum dependence of medium modifications of the nucleon-nucleon elastic cross sections
The momentum dependence of the medium modifications on nucleon-nucleon
elastic cross sections is discussed with microscopic transport theories and
numerically investigated with an updated UrQMD microscopic transport model. The
semi-peripheral Au+Au reaction at beam energy MeV is adopted as an
example. It is found that the uncertainties of the momentum dependence on
medium modifications of cross sections influence the yields of free nucleons
and their collective flows as functions of their transverse momentum and
rapidity. Among these observables, the elliptic flow is sensitively dependent
on detailed forms of the momentum dependence and more attention should be paid.
The elliptic flow is hardly influenced by the probable splitting effect of the
neutron-neutron and proton-proton cross sections so that one might pin down the
mass splitting effect of the mean-field level at high beam energies and high
nuclear densities by exploring the elliptic flow of nucleons or light clusters.Comment: 13 pages, 6 figures, 1 tabl
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