Robust stability criteria for uncertain neutral type stochastic system with Takagi–Sugeno fuzzy model and Markovian jumping parameters

In this paper, the robust stability for uncertain neutral stochastic system with Takagi–Sugeno (T–S) fuzzy model and Markovian jumping parameters (MJPs) are investigated. The jumping parameters considered here are generated from a continuous-time discrete-state homogeneous Markov process, which are governed by a Markov process with discrete and finite-state space. Some novel sufficient conditions are derived to guarantee the asymptotic stability of the equilibrium point in the mean square. By utilizing the Lyapunov–Krasovskii functional, stochastic analysis theory, some free weighting matrices and linear matrix inequality (LMI) technique, the upper bound of time-varying delay is obtained by using Matlab® control toolbox. Finally, some numerical examples are given to show the effectiveness of the obtained results.     

Antigen-responsive, microfluidic valves for single use diagnostics

The growing need for medical diagnostics in resource limited settings is driving the development of simple, standalone immunoassay devices. A capillary flow device using polymerization based amplification is capable of blocking a microfluidic channel in response to target biomaterials, enabling multiple modes of detection that require little or no supplemental instrumentation.     

Linear matrix inequality approach for synchronization control of fuzzy cellular neural networks with mixed time delays

Fuzzy cellular neural networks (FCNNs) are special kinds of cellular neural networks (CNNs). Each cell in an FCNN contains fuzzy operating abilities. The entire network is governed by cellular computing laws. The design of FCNNs is based on fuzzy local rules. In this paper, a linear matrix inequality (LMI) approach for synchronization control of FCNNs with mixed delays is investigated. Mixed delays include discrete time-varying delays and unbounded distributed delays. A dynamic control scheme is proposed to achieve the synchronization between a drive network and a response network. By constructing the Lyapunov–Krasovskii functional which contains a triple-integral term and the free-weighting matrices method an improved delay-dependent stability criterion is derived in terms of LMIs. The controller can be easily obtained by solving the derived LMIs. A numerical example and its simulations are presented to illustrate the effectiveness of the proposed method.     

Some results on abstract commutative ideal theory

Conditions are given for a multiplicative lattice to be a finite Boolean algebra. Multiplicative lattices in which semiprimary elements are primary or in which prime elements are weak meet principal are studied. The lattice of filters of a bounded commutative semilattice are investigated. Finally, we study compactly packed lattices.     

Thermo-mechanical measurement of elasto-plastic transitions during cyclic loading

The surface temperature of stainless steel SS304 low cycle fatigue specimens subjected to cyclic loading was studied using infrared thermography technique. The thermal data mapped onto the various stages of cyclic stress-strain curve shows the ability of these measurements to identify the yield points in both the compression and tension loading. Based on the results of this study, it is possible to identify the state of stress for materials such as elastic tension, plastic tension, elastic compression, plastic compression during cyclic loading using infrared thermographic data. The thermo-elastic slope and thermo-plastic slope was observed to be dependent on the prior loading cycles.     

Delay dependent stability analysis of neutral systems with mixed time-varying delays and nonlinear perturbations

This paper is concerned with the problem of stability of neutral systems with interval time-varying delays and nonlinear perturbations. The uncertainties under consideration are nonlinear time-varying parameter perturbations and norm-bounded uncertainties. A new delay-dependent stability condition is derived in terms of linear matrix inequality by constructing a new Lyapunov functional and using some integral inequalities without introducing any free-weighting matrices. Numerical examples are given to demonstrate the effectiveness and less conservativeness of the proposed methods.     

Interaction of Lamb mode (A(o)) with structural discontinuity and generation of "Turning modes" in a T-joint

In the present work, the interaction of the fundamental anti-symmetric guided Lamb mode (A_o) with a structural discontinuity in a composite structure was studied through Finite Element numerical simulations and experiments. The structural component selected for this study was a T-joint section made from glass/epoxy material. This co-cured composite structure is made-up of an upper shell (skin) and a spar as the sub-components. It was observed that when A_o mode interacts with the junction (structural discontinuity) of these sub-components, a mode-converted S_o mode is generated. Experiments were conducted using air-coupled ultrasound to validate the numerical simulations. The back-propagating “Turning modes”, which propagate from the thin region to the spar web and vice versa, were also numerically simulated and experimentally verified.     

Study a class of Hilfer fractional stochastic integrodifferential equations with Poisson jumps

Abstract

In this article, we derive the sufficient conditions for the existence of mild solutions of Hilfer fractional stochastic integrodifferential equations with nonlocal conditions and Poisson jumps in Hilbert spaces. Results will be obtained in the pth mean square sense by using the fractional calculus, semigroup theory and stochastic analysis techniques. The article generalizes many of the existing results in the literature in terms of (1) Riemann–Liouville and Caputo derivatives are the special cases. (2) In the sense of pth mean square norm. (3) Stochastic integrodifferential with nonlocal conditions and Poisson jumps. A numerical example is provided to validate the obtained theoretical results.     

\mathcal {H}_{\infty } filtering for sample data systems with stochastic sampling and Markovian jumping parameters

This paper deals with the problem of \(\mathcal {H}_{\infty }\) filtering for sample data systems that possess random jumping parameters described by a finite-state Markov process with stochastic sampling. Multiple stochastic sampling periods are considered in which each sampling period is assumed to be time varying that switches between two different values in a random way with given probability. The aim of this paper is to design a filter such that the filtering error system is stochastically stable with a prescribed \(\mathcal {H}_{\infty }\) disturbance attenuation level. Sufficient conditions for the existence of \(\mathcal {H}_{\infty }\) filters are expressed in terms of linear matrix inequalities (LMIs), which can be solved by using Matlab LMI toolbox. Numerical examples are given to illustrate the effectiveness of the proposed result including a realistic Transmission Control Protocol network model.