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Abstract: In this paper we consider constructing some higher-order modifications of Newton’s method for solving nonlinear equations which increase the order of convergence of existing iterative methods by one or two or three units. This construction can be applied to any iteration formula, and per iteration the resulting methods add only one additional function evaluation to increase the order. Some illustrative examples are provided and several numerical results are given to show the performance of the presented methods. [Copyright &y& Elsevier]

Abstract: Modern codes for the numerical solution of Initial Value Problems (IVPs) in ODEs are based in adaptive methods that, for a user supplied tolerance , attempt to advance the integration selecting the size of each step so that some measure of the local error is . Although this policy does not ensure that the global errors are under the prescribed tolerance, after the early studies of Stetter [Considerations concerning a theory for ODE-solvers, in: R. Burlisch, R.D. Grigorieff, J. Schröder (Eds.), Numerical Treatment of Differential Equations, Proceedings of Oberwolfach, 1976, Lecture Notes in Mathematics, vol. 631, Springer, Berlin, 1978, pp. 188–200; Tolerance proportionality in ODE codes, in: R. März (Ed.), Proceedings of the Second Conference on Numerical Treatment of Ordinary Differential Equations, Humbold University, Berlin, 1980, pp. 109–123] and the extensions of Higham [Global error versus tolerance for explicit Runge–Kutta methods, IMA J. Numer. Anal. 11 (1991) 457–480; The tolerance proportionality of adaptive ODE solvers, J. Comput. Appl. Math. 45 (1993) 227–236; The reliability of standard local error control algorithms for initial value ordinary differential equations, in: Proceedings: The Quality of Numerical Software: Assessment and Enhancement, IFIP Series, Springer, Berlin, 1997], it has been proved that in many existing explicit Runge–Kutta codes the global errors behave asymptotically as some rational power of . This step-size policy, for a given IVP, determines at each grid point a new step-size so that is a continuous function of . In this paper a study of the tolerance proportionality property under a discontinuous step-size policy that does not allow to change the size of the step if the step-size ratio between two consecutive steps is close to unity is carried out. This theory is applied to obtain global error estimations in a few problems that have been solved with the code Gauss2 [S. Gonzalez-Pinto, R. Rojas-Bello, Gauss2, a Fortran 90 code for second order initial value problems, http://www.netlib.org/ode/ ], based on an adaptive two stage Runge–Kutta–Gauss method with this discontinuous step-size policy. [Copyright &y& Elsevier]

Abstract: In this paper, variational iteration method (VIM) is used to obtain numerical and analytical solutions for the Zakharov–Kuznetsov equations with fully nonlinear dispersion. Comparisons with exact solution show that the VIM is a powerful method for the solution of nonlinear equations. [Copyright &y& Elsevier]

Abstract: This paper deals with the approximate solution of multi-pantograph equation with nonhomogenous term in terms of Taylor polynomials. The technique we have used is based on a Taylor matrix method. In addition, some numerical examples are presented to show the properties of the given method and the results are discussed. [Copyright &y& Elsevier]

Abstract: In this paper we investigate the convergence of subdivision schemes associated with masks being polynomially decay sequences. Two-scale vector refinement equations are the formwhere the vector of functions is in and is polynomially decay sequence of matrices called refinement mask. Associated with the mask a is a linear operator on given byBy using same methods in [B. Han, R. Q. Jia, Characterization of Riesz bases of wavelets generated from multiresolution analysis, manuscript]; [B. Han, Refinable functions and cascade algorithms in weighted spaces with infinitely supported masks, manuscript]; [R.Q. Jia, Q.T. Jiang, Z.W. Shen, Convergence of cascade algorithms associated with nonhomogeneous refinement equations, Proc. Amer. Math. Soc. 129 (2001) 415–427]; [R.Q. Jia, Convergence of vector subdivision schemes and construction of biorthogonal multiple wavelets, in: Advances in Wavelet, Hong Kong,1997, Springer, Singapore, 1998, pp. 199–227], a characterization of convergence of the sequences in the -norm is given, which extends the main results in [R.Q. Jia, S.D. Riemenschneider, D.X. Zhou, Vector subdivision schemes and multiple wavelets, Math. Comp. 67 (1998) 1533–1563] on convergence of the subdivision schemes associated with a finitely supported mask to the case in which mask a is polynomially decay sequence. As an application, we also obtain a characterization of smoothness of solutions of the refinement equation mentioned above for the case . [Copyright &y& Elsevier]

Abstract: By using a new type of smoothing function, we first reformulate the generalized nonlinear complementarity problem over a polyhedral cone as a smoothing system of equations, and then develop a smoothing Newton-type method for solving it. For the proposed method, we obtain its global convergence under milder conditions, and we further establish its local superlinear (quadratic) convergence rate under the BD-regular assumption. Preliminary numerical experiments are also reported in this paper. [Copyright &y& Elsevier]

Abstract: In this paper, a special lattice Boltzmann model is proposed to simulate two-dimensional unsteady Burgers’ equation. The maximum principle and the stability are proved. The model has been verified by several test examples. Excellent agreement is obtained between numerical predictions and exact solutions. The cases of steep oblique shock waves are solved and compared with the two-point compact scheme results. The study indicates that lattice Boltzmann model is highly stable and efficient even for the problems with severe gradients. [Copyright &y& Elsevier]

Abstract: In this paper we shall consider the following nonlinear impulsive delay population model:where m is a positive integer, , and are positive periodic continuous functions with period . In the nondelay case (), we show that (0.1) has a unique positive periodic solution which is globally asymptotically stable. In the delay case, we present sufficient conditions for the global attractivity of . Our results imply that under the appropriate linear periodic impulsive perturbations, the impulsive delay equation (0.1) preserves the original periodic property of the nonimpulsive delay equation. In particular, our work extends and improves some known results. [Copyright &y& Elsevier]

Abstract: Exclusion algorithms have been used recently to find all solutions of a system of nonlinear equations or to find the global minimum of a function over a compact domain. These algorithms are based on a minimization condition that can be applied to each cell in the domain. In this paper, we consider Lipschitz functions of order and give a new minimization condition for the exclusion algorithm. Furthermore, convergence and complexity results are presented for such algorithm. [Copyright &y& Elsevier]

Abstract: Inexact Newton method is one of the effective tools for solving systems of nonlinear equations. In each iteration step of the method, a forcing term, which is used to control the accuracy when solving the Newton equations, is required. The choice of the forcing terms is of great importance due to their strong influence on the behavior of the inexact Newton method, including its convergence, efficiency, and even robustness. To improve the efficiency and robustness of the inexact Newton method, a new strategy to determine the forcing terms is given in this paper. With the new forcing terms, the inexact Newton method is locally Q-superlinearly convergent. Numerical results are presented to support the effectiveness of the new forcing terms. [Copyright &y& Elsevier]

Abstract: Jackiewicz and Tracogna [SIAM J. Numer. Anal. 32 (1995) 1390–1427] proposed a general formulation of two step Runge–Kutta (TSRK) methods. Using formulas for two-step pairs of TSRK methods constructed in [Japan JIAM 19 (2002) 227–248], Jackiewicz and Verner obtain results for order 8 pairs that fail to show this designated order. Hairer and Wanner [SIAM J. Numer. Anal. 34 (1997) 2087–2089] identify the problem by using B-series to formulate a complete set of order conditions for TSRK methods, and emphasize that special starting methods are necessary for the first step of implementation. They observe that for methods with stage order at least , and design order , starting methods of order at least are sufficient. In this paper, the more general challenge to provide correct starting values for methods of low stage-order is met by showing how perturbed starting values should be selected for methods of order 6 and stage-order 3. The approach is sufficiently general that it may (and later will) be provided for such methods of higher orders. Evidence of the accompanying improvement in the implementation of TSRK methods illustrates that carefully designed starting methods are essential for efficient production codes based on methods of low stage-order. [Copyright &y& Elsevier]

Abstract: In this paper, the dynamics of the forced Burgers equation: subject to both Neumann boundary conditions and periodic boundary conditions using boundary and distributed control is analyzed. For the boundary control problem, we show that the controlled unforced Burgers equation (i.e., the closed loop system) is exponentially stable when the viscosity is known, and globally asymptotically stable when is unknown. As for the distributed control problem, we apply Karhunen–Loéve decomposition on the dynamics of the forced Burgers equation to generate a low dimensional dynamical system whose dynamics is similar to that of Burgers equation. Then, a feedback linearization control is used on the reduced system to exponentially stabilize the dynamics of the equation. Numerical simulations for the boundary and distributed controls are presented to support the analytical results. [Copyright &y& Elsevier]

Abstract: Periodical stabilization problems for switched linear systems are investigated in this paper. For autonomous switched systems, if there exists a stable convex combination of the subsystems, then a periodically switching signal can be constructed such that the overall system is asymptotically stable. Based on this fact, for switched control systems, corresponding sufficient conditions are presented under which constant/switching direct/observer-based state feedback controller can be designed such that the corresponding closed-loop systems are asymptotically stable under some periodically switching signal. Some numerical examples are given to illustrate our results. [Copyright &y& Elsevier]

Abstract: For any conforming mesh, the application of a skeleton-regular partition over each element in the mesh, produces a conforming mesh such that all the topological elements of the same dimension are subdivided into the same number of child-elements. Every skeleton-regular partition has associated special constitutive (recurrence) equations. In this paper the average adjacencies associated with the skeleton-regular partitions in 3D are studied. In three-dimensions different values for the asymptotic number of average adjacencies are obtained depending on the considered partition, in contrast with the two-dimensional case [J. Comput. Appl. Math. 140 (2002) 673]. In addition, a priori formulae for the average asymptotic adjacency relations for any skeleton-regular partition in 3D are provided. [Copyright &y& Elsevier]

Abstract: This paper is devoted to the study of the stability of the solutions of the first order implicit difference periodic equationWe prove that if there exist a pair of lower and upper solutions respectively of this problem together with a suitable condition on the function and it has at most two solutions in the sector , then one of such solutions is asymptotically stable. Moreover, it is proved the optimality of the given results, both in the conditions imposed on and in the number of the periodic solutions. [Copyright &y& Elsevier]

By using the exponential dichotomy theory, this paper investigated the existence of almost periodic solutions of forced Lie´nard-type equations with time delays. A sufficient condition on the existence of almost periodic solutions for this class equation is obtained. [Copyright &y& Elsevier]