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This paper deals with the problems of ℋ∞ performance and stability analysis for linear systems with interval time-varying delays. It is assumed that the parameter uncertainties are of stochastic properties to represent random change of various environments. By constructing a newly augmented Lyapunov-Krasovskii functional, less conservative criteria of the concerned systems are introduced with the framework of linear matrix inequalities (LMIs). Four numerical examples are given to show the improvements over the existing ones and the effectiveness of the proposed methods. [ABSTRACT FROM AUTHOR]

The problem of stability analysis and H∞ output tracking control for linear systems with time-varying delays is studied. First, by construction of a newly augmented Lyapunov-Krasovskii functional, a delay-dependent stability criterion for nominal systems with time-varying delays is established in terms of linear matrix inequalities (LMIs). Second, based on the H∞ sense, the proposed method is extended to solve the problem of designing an H∞ output tracking controller to track the output of a given reference model. Finally, three examples are included to show the validity and effectiveness of the presented delay-dependent stability and the H∞ output tracking controller design. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the problem of ℋ∞ synchronization for chaotic neural networks with time-varying delays. A new model of the networks with disturbances in both master and slave systems is presented. By constructing a suitable Lyapunov—Krasovskii functional and using a reciprocally convex approach, a novel ℋ∞ synchronization criterion for the networks concerned is established in terms of linear matrix inequalities (LMIs) which can be easily solved by various effective optimization algorithms. Two numerical examples are given to illustrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

In this study, a fibre-optic dosemeter (FOD) using an organic scintillator with a diameter of 0.5 mm for photon-beam therapy dosimetry was fabricated. The fabricated dosemeter has many advantages, including water equivalence, high spatial resolution, remote sensing and real-time measurement. The scintillating light generated from an organic-dosemeter probe embedded in a solid-water stack phantom is guided to a photomultiplier tube and an electrometer via 20 m of plastic optical fibre. Using this FOD, the skin dose and the percentage depth dose in the build-up region according to the depths of a solid-water stack phantom are measured with 6- and 15-MV photon-beam energies with field sizes of 10×10 and 20×20 cm2, respectively. The results are compared with those measured using conventional dosimetry films. It is expected that the proposed FOD can be effectively used in radiotherapy dosimetry for accurate measurement of the skin dose and the depth dose distribution in the build-up region due to its high spatial resolution. [ABSTRACT FROM PUBLISHER]

This study is concerned with the stability problem for uncertain discrete-time systems with interval time-varying delays. By construction of an augmented Lyapunov-Krasovskii's functional and utilisation of new zero equalities, improved delay-dependent criteria for the stability of the systems are derived for guaranteeing the asymptotic stability of the concerned systems. The effectiveness and the reduced conservatism of the derived results are demonstrated by three illustrative examples. [ABSTRACT FROM AUTHOR]