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Filtering for uncertain 2-D discrete systems with state delays
This is the post print version of the article. The official published version can be obtained from the link below - Copyright 2007 Elsevier Ltd.This paper is concerned with the problem of robust H∞ filtering for two-dimensional (2-D) discrete systems with time-delays in states. The 2-D systems under consideration are described in terms of the well-known Fornasini–Marchesini local state-space (FMLSS) models with time-delays. Our attention is focused on the design of a full-order filter such that the filtering error system is guaranteed to be asymptotically stable with a prescribed H∞ disturbance attenuation performance. Sufficient conditions for the existence of desired filters are established by using a linear matrix inequality (LMI) approach, and the corresponding filter design problem is then cast into a convex optimization problem that can be efficiently solved by resorting to some standard numerical software. Furthermore, the obtained results are extended to more general cases where the system matrices contain either polytopic or norm-bounded parameter uncertainties. A simulation example is provided to illustrate the effectiveness of the proposed design method.This work was partially supported by the National Natural Science Foundation of China (60504008), Program for New Century Excellent Talents in University of China and the Postdoctoral Science Foundation of China (20060390231)
Application of NASTRAN for stress analysis of left ventricle of the heart
Knowing the stress and strain distributions in the left ventricular wall of the heart is a prerequisite for the determination of the muscle elasticity and contractility in the process of assessing the functional status of the heart. NASTRAN was applied for the calculation of these stresses and strains and to help in verifying the results obtained by the computer program FEAMPS which was specifically designed for the plane-strain finite-element analysis of the left ventricular cross sections. Adopted for the analysis are the true shape and dimensions of the cross sections reconstructed from multiplanar X-ray views of a left ventricle which was surgically isolated from a dog's heart but metabolically supported to sustain its beating. A preprocessor was prepared to accommodate both FEAMPS and NASTRAN, and it has also facilitated the application of both the triangular element and isoparameteric quadrilateral element versions of NASTRAN. The stresses in several crucial regions of the left ventricular wall calculated by these two independently developed computer programs are found to be in good agreement. Such confirmation of the results is essential in the development of a method which assesses the heart performance
Research on digital transducer principles. Volume 8 - Electrical conduction mechanisms in metal-semiconductor-polymer thin film structures, 1 July - 30 June 1968
Charge transport mechanism in metal semiconductor polymer thin film
Determinations of upper critical field in continuous Ginzburg-Landau model
Novel procedures to determine the upper critical field have been
proposed within a continuous Ginzburg-Landau model. Unlike conventional
methods, where is obtained through the determination of the smallest
eigenvalue of an appropriate eigen equation, the square of the magnetic field
is treated as eigenvalue problems so that the upper critical field can be
directly deduced. The calculated from the two procedures are
consistent with each other and in reasonably good agreement with existing
theories and experiments. The profile of the order parameter associated with
is found to be Gaussian-like, further validating the methodology
proposed. The convergences of the two procedures are also studied.Comment: Revtex4, 8 pages, 4 figures, references modified, figures and table
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Analytic Expression for Exact Ground State Energy Based on an Operator Method for a Class of Anharmonic Potentials
A general procedure based on shift operators is formulated to deal with
anharmonic potentials. It is possible to extract the ground state energy
analytically using our method provided certain consistency relations are
satisfied. Analytic expressions for the exact ground state energy have also
been derived specifically for a large class of the one-dimensional oscillator
with cubic-quartic anharmonic terms. Our analytical results can be used to
check the accuracy of existing numerical methods, for instance the method of
state-dependent diagonalization. Our results also agree with the asymptotic
behavior in the divergent pertubative expansion of quartic harmonic oscillator.Comment: LaTeX with six figure (gif) files; Submitted to Phys. Rev.
Influence of damping and mass-stiffness discontinuities upon the dynamic stability of a free-free beam under a gimballed thrust of periodically-varying magnitude Technical memorandum no. 103
Damping and mass stiffness discontinuity effects on dynamic stability of free-free beam under gimballed pulsating end thrus
Hysteresis and Anisotropic Magnetoresistance in Antiferromagnetic
The out-of-plane resistivity () and magnetoresistivity (MR) are
studied in antiferromangetic (AF) single crystals, which
have three types of noncollinear antiferromangetic spin structures. The
apparent signatures are observed in measured at the zero-field and
14 T at the spin structure transitions, giving a definite evidence for the
itinerant electrons directly coupled to the localized spins. One of striking
feature is an anisotropy of the MR with a fourfold symmetry upon rotating the
external field (B) within ab plane in the different phases, while twofold
symmetry at spin reorientation transition temperatures. The intriguing thermal
hysteresis in and magnetic hysteresis in MR are observed at spin
reorientation transition temperatures.Comment: 4 pages, 4 figure
Topology of Entanglement in Multipartite States with Translational Invariance
The topology of entanglement in multipartite states with translational
invariance is discussed in this article. Two global features are foundby which
one can distinguish distinct states. These are the cyclic unit and the
quantised geometric phase. Furthermore the topology is indicated by the
fractional spin. Finally a scheme is presented for preparation of these types
of states in spin chain systems, in which the degeneracy of the energy levels
characterises the robustness of the states with translational invariance.Comment: major revision. accepted by EPJ
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