we prove a strong convergence theorem for the modified noor iterations‎ ‎in the framework of cat(0) spaces‎. ‎our results extend and improve the corresponding results of‎ ‎x‎. ‎qin‎, ‎y‎. ‎su and m‎. ‎shang‎, ‎t‎. ‎h‎. ‎kim and h‎. ‎k‎. ‎xu and s‎. ‎saejung‎ ‎and some others‎.

In this paper, we present new preconditioned modified accelerated overrelaxation (MAOR) method for solving linear systems. We compare the spectral radii of the iteration matrices of the preconditioned and the original methods. The comparison results show that the preconditioned MAOR method converges faster than the MAOR method whenever the MAOR method is convergent. Finally, we give one numeric...

In this paper we discuss λ-policy iteration, a method for exact and approximate dynamic programming. It is intermediate between the classical value iteration (VI) and policy iteration (PI) methods, and it is closely related to optimistic (also known as modified) PI, whereby each policy evaluation is done approximately, using a finite number of VI. We review the theory of the method and associat...

in this paper, the multistage variational iteration method is implemented to solve a general form of the system of first-order differential equations. the convergence of the proposed method is given. to illustrate the proposed method, it is applied to a model for hiv infection of cd4+ t cells and the numerical results are compared with those of a recently proposed method.

This paper introduces an efficient modified derivative-free method for bound constrained optimization problems. It is based on the coordinate search method. During the running of the algorithm, it incorporates the progressive obtained local information into the current iteration. Actually, after we find two different suitable descent directions, we introduce the composite expansion step. By doi...

In this paper, we suggest and analyze a new family of iterative methods for finding zeros of multiplicity of nonlinear equations by using the variational iteration technique. These new methods include the Halley method and its variants forms as special cases. We also give several examples to illustrate the efficiency of these methods. Comparison with modified Newton method is also given. These ...

In this paper, we propose a discrepancy rule-based method to automatically choose the regularization parameters for total variation image restoration problems. The regularization parameters are adjusted dynamically in each iteration. Numerical results are shown to illustrate the performance of the proposed method. AMS subject classifications: 65K10, 68U10

We consider the infinite-horizon γ-discounted optimal control problem formalized by Markov Decision Processes. Running any instance of Modified Policy Iteration—a family of algorithms that can interpolate between Value and Policy Iteration—with an error at each iteration is known to lead to stationary policies that are at least 2γ (1−γ)2 -optimal. Variations of Value and Policy Iteration, that ...

In this paper we study the solution of large sparse augmented linear systems. The generalized modified extrapolated SOR (GMESOR) method is considered. We find sufficient conditions for GMESOR to converge and determine its optimal iteration parameters and the corresponding minimum value of its convergence factor. Under the assumption that the eigenvalues of a key matrix are real it is shown that...

The nonlinear coupled system of diffusion equations are solved analytically for the transport and kinetics of electrons and reactant in the layer of a modified electrode. Analytical expressions of concentrations of substrate and mediator are presented using He’s variational iteration method. The approximate expression of current for microheterogeneous catalysis at isonomer or redox polymer modi...