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Abstract: In this paper, the H ∞ analysis problem is studied for a general class of nonlinear stochastic systems with time-delay. The stochastic systems are described in terms of stochastic functional differential equations. The Razumikhin-type lemma is employed to establish sufficient conditions for the time-delay stochastic systems to be internally stable, and the H ∞ analysis problem is studied in order to quantify the disturbance rejection attenuation level of the nonlinear stochastic time-delay system. In particular, the paper obtains the general conditions under which the L 2 gain of the system is less than or equal to a given constant. Some easy-to-test criteria are also given so as to determine whether the nonlinear stochastic time-delay system under investigation is internally stable and whether it achieves certain H ∞ performance index. Finally, illustrative examples are provided to show the usefulness of the proposed theory. [Copyright &y& Elsevier]

Abstract: The economic dispatch problem (EDP) is an optimization problem useful in power systems operation. The objective of the EDP of electric power generation, whose characteristics are complex and highly non-linear, is to schedule the committed generating unit outputs so as to meet the required load demand at minimum operating cost while satisfying system constraints. Recently, as an alternative to the conventional mathematical approaches, modern heuristic optimization techniques have been given much attention by many researchers due to their ability to find an almost global optimal solution in EDPs. As special mechanism to avoid being trapped in local minimum, the ergodicity property of chaotic sequences has been used as optimization technique in EDPs. Based on the chaos theory, this paper discusses the design and validation of an optimization procedure based on a chaotic artificial immune network approach based on Zaslavsky’s map. The optimization approach based on chaotic artificial immune network is validated for a test system consisting of 13 thermal units whose incremental fuel cost function takes into account the valve-point loading effects. Simulation results and comparisons show that the chaotic artificial immune network approach is competitive in performance with other optimization approaches presented in literature and is also an attractive tool to be used on applications in the power systems field. [Copyright &y& Elsevier]

Abstract: This paper proposes a technique aiming to compute all global minimizers, while avoiding local minimizers, through chaotic ant swarm (CAS) optimization method. This technique incorporates the recently proposed deflection and repulsion techniques to alleviate local minimizers. Those approaches can be used in combination with CAS to detect all global minimizers effectively. The performance of the algorithm is illustrated on test problems of global optimization. Experimental results indicate the effectiveness of the proposed algorithm. [Copyright &y& Elsevier]

Abstract: This paper investigates the H ∞ non-fragile observer-based controls for continuous dynamical systems. Two types of uncertainties which perturb the gains of control and observer are studied. Linear matrix inequality (LMI) optimization approach is used to design the H ∞ non-fragile observer-based controls. The feedback control and observer gains are given from LMI optimization feasible solution. A numerical example is given to illustrate our method. [Copyright &y& Elsevier]

Abstract: This paper studies an optimization problem: multi-traveling salesman problem (MTSP), which is an extension of the well known TSP. A columnar competitive model (CCM) of neural networks incorporates with a winner-take-all learning rule is employed to solve the MTSP. Stability conditions of CCM for MTSP is exploited by mathematical analysis. Parameters settings of the network for guaranteeing the network converges to valid solutions are discussed in detail. Simulations are carried out to illustrate the performance of the columnar competitive model compare to the heuristic algorithms: Tabu Search. [Copyright &y& Elsevier]

Abstract: In this paper, a generalized periodic n-species Gilpin–Ayala competition systems with impulsive effect is investigated. The sufficient conditions are derived for the permanence of the system. We discuss the stabilities of trivial solution and bounded periodic solution. By using the method of coincidence degree, a set of sufficient conditions are derived for the existence of at least one strictly positive componentwise periodic solution, the example shows that our criteria are easily verifiable. [Copyright &y& Elsevier]

Abstract: In this paper it is presented a detailed numerical investigation of acoustic emission signals obtained from test samples of fibreglass reinforced polymeric matrix composites, when subjected to tensile and flexural tests. Various fractal indices, characteristic of the signals emitted at the different structural failures of the test samples and which satisfy non-stationary distributions, have been determined. From the results obtained for these indices, related to the Hurst analysis, detrended fluctuation analysis, minimal cover analysis and to the boxcounting dimension analysis, it has been shown they can discriminate the different failure mechanisms and, therefore, they constitute their signature. [Copyright &y& Elsevier]

Abstract: In this paper, (2+1)-dimensional Gardner equation is investigated using a sine-Gordon equation expansion method, which was presented via a generalized sine-Gordon reduction equation and a new transformation. As a consequence, it is shown that the method is more powerful to obtain many types of new doubly periodic solutions of (2+1)-dimensional Gardner equation. In particular, solitary wave solutions are also given as simple limits of doubly periodic solutions. [Copyright &y& Elsevier]

Abstract: The paper is written partially very informal with one formal section about hyper Kähler manifolds of the E-infinity fuzzy type. We discuss spinors and the particle content of minimally extended super-symmetric standard model. [Copyright &y& Elsevier]