371,715 research outputs found
Fault tolerant quantum key distribution protocol with collective random unitary noise
We propose an easy implementable prepare-and-measure protocol for robust
quantum key distribution with photon polarization. The protocol is fault
tolerant against collective random unitary channel noise. The protocol does not
need any collective quantum measurement or quantum memory. A security proof and
a specific linear optical realization using spontaneous parametric down
conversion are given.Comment: Accepted by PRA as a Rapid Communicatio
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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)
Biodegradable Polylactic Acid (PLA) Microstructures for Scaffold Applications
In this research, we present a simple and cost effective soft lithographic
process to fabricate PLA scaffolds for tissue engineering. In which, the
negative photoresist JSR THB-120N was spun on a glass subtract followed by
conventional UV lithographic processes to fabricate the master to cast the PDMS
elastomeric mold. A thin poly(vinyl alcohol) (PVA) layer was used as a mode
release such that the PLA scaffold can be easily peeled off. The PLA precursor
solution was then cast onto the PDMS mold to form the PLA microstructures.
After evaporating the solvent, the PLA microstructures can be easily peeled off
from the PDMS mold. Experimental results show that the desired microvessels
scaffold can be successfully transferred to the biodegradable polymer PLA.Comment: Submitted on behalf of EDA Publishing Association
(http://irevues.inist.fr/EDA-Publishing
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
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