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Computational & Applied Mathematics, Volume: 29, Número: 1, Publicado: 2010
  • Analysis of an impulsive pest management SEI model with nonlinear incidence rate

    Wang, Xia; Song, Xinyu

    Resumo em Inglês:

    According to biological strategy for pest control, we investigate the dynamic behavior of a pest management SEI model with nonlinear incidence concerning impulsive strategy-periodic releasing infected pests at fixed times. We prove that all solutions of the system are uniformly ultimately bounded and there exists a globally asymptotically attractive pest-eradication periodic solution when the impulsive period satisfies A1. When the impulsive period satisfies A2, the stability of pest-eradication periodic solution is lost, the system is uniformly permanent. Thus, we can use the stability of the positive periodic solution and its period to control insect pests at acceptably low levels.
  • Some derivative free quadratic and cubic convergence iterative formulas for solving nonlinear equations

    Dehghan, Mehdi; Hajarian, Masoud

    Resumo em Inglês:

    Finding the zeros of a nonlinear equation ƒ (x) = 0, is a classical problem which has nice applications in various branches of science and engineering. In this paper, we introduce four iterative methods which is based on the central-difference and forward-difference approximations to derivatives. It is proved that three of the four methods have cubic convergence and another method has quadratic convergence. The best property of these methods are that do not need to calculate any derivative. In order to demonstrate convergence properties of the introduced methods, several numerical examples are given.
  • The rates in complete moment convergence for negatively associated sequences

    Zhao, Yuexu; Qiu, Zheyong; Zhang, Chunguo; Zhao, Yehua

    Resumo em Inglês:

    Let X1, X2,... be a strictly stationary and negatively associated sequence of random variables with mean zero and positive, finite variance, set Sn = X1+ ... + Xn, Mn = max1 < k < n |Sk|. Under appropriate moment conditions, we obtain precise rates in law of the logarithm for the moment convergence of Sn and Mn.
  • A kind of Bernoulli-type quasi-interpolation operator with univariate multiquadrics

    Wang, Ren-Hong; Xu, Min

    Resumo em Inglês:

    In this paper, a kind of Bernoulli-type operator is proposed by combining a univariate multiquadric quasi-interpolation operator with the generalized Taylor polynomial. With an assumption on the shape-preserving parameter c, the convergence rate of the new operator is derived, which indicates that it could produce the desired precision. Numerical comparisons show that this method offers a higher degree of accuracy. Moreover, the associated algorithm is easily implemented.
  • Preconditioners for higher order finite element discretizations of H(div)-elliptic problem

    Wang, Junxian; Zhong, Liuqiang; Shu, Shi

    Resumo em Inglês:

    In this paper, we are concerned with the fast solvers for higher order finite element discretizations of H(div)-elliptic problem. We present the preconditioners for the first family and second family of higher order divergence conforming element equations, respectively. By combining the stable decompositions of two kinds of finite element spaces with the abstract theory of auxiliary space preconditioning, we prove that the corresponding condition numbers of our preconditioners are uniformly bounded on quasi-uniform grids.
  • Partial sums of analytic functions of bounded turning with applications

    Darus, Maslina; Ibrahim, Rabha W.

    Resumo em Inglês:

    In this article, we determine certain conditions under which the partial sums of the multiplier integral operators of analytic univalent functions of bounded turning are also of bounded turning.
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