International Journal of Computer Mathematics (INT J COMPUT MATH )

Publisher: Taylor & Francis

Description

Section A: Computer Systems: Programming Languages. This section contains work concerning research and development in computer systems and the theory of programming languages. Papers relating directly or indirectly to aspects of these fields are welcome. Of great interest is work in computer systems architectures and organisation, computer software and data structures, mathematical logic, formal languages, automata, artificial intelligence, parallelism and concurrency, analysis of algorithms, computational complexity, combinatorial algorithms, and symbol manipulation. The journal is intended to provide a forum for the expression of new ideas, as well as a place for exposition of these areas of knowledge. Section B: Computational Methods: Application. This section contains work concerning mathematical techniques that are of interest to computer users in the fields of numerical analysis, mathematical software, discrete mathematics, computational geometry and graphics, image processing, pattern recognition, simulation and modelling, operations research and applied mathematics in general.

  • Impact factor
    0.54
    Show impact factor history
     
    Impact factor
  • 5-year impact
    0.56
  • Cited half-life
    5.00
  • Immediacy index
    0.37
  • Eigenfactor
    0.00
  • Article influence
    0.23
  • Website
    International Journal of Computer Mathematics website
  • Other titles
    International journal of computer mathematics (Online)
  • ISSN
    0020-7160
  • OCLC
    50166329
  • Material type
    Document, Periodical, Internet resource
  • Document type
    Internet Resource, Computer File, Journal / Magazine / Newspaper

Publisher details

Taylor & Francis

  • Pre-print
    • Author can archive a pre-print version
  • Post-print
    • Author cannot archive a post-print version
  • Restrictions
    • 12 month embargo for STM, Behavioural Science and Public Health Journals
    • 18 month embargo for SSH journals
  • Conditions
    • Some individual journals may have policies prohibiting pre-print archiving
    • Pre-print on authors own website, Institutional or Subject Repository
    • Post-print on authors own website, Institutional or Subject Repository
    • Publisher's version/PDF cannot be used
    • On a non-profit server
    • Published source must be acknowledged
    • Must link to publisher version
    • Set statements to accompany deposits (see policy)
    • Publisher will deposit to PMC on behalf of NIH authors.
    • STM: Science, Technology and Medicine
    • SSH: Social Science and Humanities
    • 'Taylor & Francis (Psychology Press)' is an imprint of 'Taylor & Francis'
  • Classification
    ​ yellow

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: A novel variational model for removing multiplicative noise is proposed in this paper. In the model, a novel regularization term is elaborately designed which is inherently equivalent to a combination of the classical total variation regularizer and a nonconvex regularizer. The proposed regularization term, on the one hand, can better remove the noise in homogeneous regions of a noisy image and, on the other hand, can preserve edge details of the image during the denoising process. In order to solve the model efficiently, we design an alternating iteration process in which two coupling minimization problems are solved. For each of the two minimization problems, the existence and uniqueness of their solutions are proved under some necessary assumptions. Numerical results are reported to demonstrate the effectiveness of the proposed regularization term for multiplicative noise removal.
    International Journal of Computer Mathematics 10/2014; 91(10).
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    ABSTRACT: In this paper, we give some new properties of edge chromatic critical graphs, and give new lower bounds for the average degree of Δ-critical graphs with Δ=11, 12 by the use of these properties.
    International Journal of Computer Mathematics 10/2014; 91(10).
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    ABSTRACT: A subset F of vertices of a graph G is called a vertex cover P k set if every path of order k in G contains at least one vertex from F. Denote by ψk (G) the minimum cardinality of a vertex cover P k set in G. The vertex cover P k (VCP k ) problem is to find a minimum vertex cover P k set. It is easy to see that the VCP 2 problem corresponds to the well-known vertex cover problem. In this paper, we restrict our attention to the VCP 4 problem in cubic graphs. The paper proves that the VCP 4 problem is NP-hard for cubic graphs. Further, we give sharp lower and upper bounds on ψ4(G) for cubic graphs and propose a 2-approximation algorithm for the VCP 4 problem in cubic graphs.
    International Journal of Computer Mathematics 10/2014; 91(10).
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    ABSTRACT: The classical composite mid-point rectangle rule for the computation of Cauchy principal value integrals is discussed. When the singular point coincides with some priori known point, the convergence rate of the mid-point rectangle rule is higher than the globally one the same as the Riemann integral which is called as superconvergence phenomenon. The superconvergence phenomenon of the composite mid-rectangle rule occurs at certain local coordinate of each subinterval and the corresponding superconvergence error estimate is obtained. At last,some numerical examples are provided to validate the theoretical analysis.
    International Journal of Computer Mathematics 10/2014; 91(10).
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    ABSTRACT: In this paper, a numerical algorithm is proposed based on the method of fundamental solutions (MFS) for the Cauchy problem connected with the Laplace equation in ℝ2. The major advantage of the modified MFS is to keep a very basic natural property, i.e. the invariance under trivial coordinate changes in the problem description. The method combines Newton's method and classic Tikhonov regularization to solve an inverse problem. The numerical convergence, accuracy, and stability of the method with respect to increasing the number of source points, and decreasing the amount of noise added into the input data, respectively, are also analysed with some examples, even for high noise levels.
    International Journal of Computer Mathematics 10/2014; 91(10):2185-2198.
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    ABSTRACT: In this paper, we first prove the strong convergence of the split-step theta methods for non-autonomous stochastic differential equations under a linear growth condition on the diffusion coefficient and a one-sided Lipschitz condition on the drift coefficient. Then, if the drift coefficient satisfies a polynomial growth condition, we further get the rate of convergence. Finally, the obtained results are supported by numerical experiments.
    International Journal of Computer Mathematics 10/2014; 91(10).
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    ABSTRACT: A strongly connected digraph D is hyper-λ if the removal of any minimum arc cut of D results in exactly two strong components, one of which is a singleton. We define a hyper-λ digraph D to be m-hyper-λ if D−S is still hyper-λ for any arc set S with ∣S∣≤m. The maximum integer of such m, denoted by H λ(D), is said to be the arc fault tolerance of D on the hyper-λ property. H λ(D) is an index to measure the reliability of networks. In this paper, we study H λ(D) for the cartesian product digraph D=D 1×D 2. We give a necessary and sufficient condition for D 1×D 2 to be hyper-λ and give the lower and upper bounds on H λ(D 1×D 2). An example shows that the lower and upper bounds are best possible. In particular, exact values of H λ(D 1×D 2) are obtained in special cases. These results are also generalized to the cartesian product of n strongly connected digraphs.
    International Journal of Computer Mathematics 10/2014; 91(10).
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    ABSTRACT: Let D be a digraph with vertex set V(D) and arc set A(D) and let f=(f −, f +) be a pair of functions defined on V(D). Let H be a km-subdigraph of D. In this paper, it is proved that every (0, mf−m+1)-digraph has a (0, f)-factorization k-orthogonal to H if f(x)≥3k−2 for each x∈V(D).
    International Journal of Computer Mathematics 10/2014; 91(10).
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    ABSTRACT: An implicit second-order finite difference scheme, which is unconditionally stable, is employed to discretize fractional advection–diffusion equations with constant coefficients. The resulting systems are full, unsymmetric, and possess Toeplitz structure. Circulant and skew-circulant splitting iteration is employed for solving the Toeplitz system. The method is proved to be convergent unconditionally to the solution of the linear system. Numerical examples show that the convergence rate of the method is fast.
    International Journal of Computer Mathematics 10/2014; 91(10).
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    ABSTRACT: A graph is clique-perfect if the maximum size of a clique-independent set (a set of pairwise disjoint maximal cliques) and the minimum size of a clique-transversal set (a set of vertices meeting every maximal clique) coincide for each induced subgraph. A graph is balanced if its clique-matrix contains no square submatrix of odd size with exactly two ones per row and column. In this work, we give linear-time recognition algorithms and minimal forbidden induced subgraph characterizations of clique-perfectness and balancedness of P 4-tidy graphs and a linear-time algorithm for computing a maximum clique-independent set and a minimum clique-transversal set for any P 4-tidy graph. We also give a minimal forbidden induced subgraph characterization and a linear-time recognition algorithm for balancedness of paw-free graphs. Finally, we show that clique-perfectness of diamond-free graphs can be decided in polynomial time by showing that a diamond-free graph is clique-perfect if and only if it is balanced.
    International Journal of Computer Mathematics 10/2014; 91(10).
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    ABSTRACT: Recently, there has been a considerable amount of interest and practice in solving many problems of several applied fields by fuzzy polynomials. In this paper, we have designed an artificial fuzzified feed-back neural network. With this design, we are able to find a solution of fully fuzzy polynomial (FFP) with degree n. This neural network can get a fuzzy vector as an input, and calculates its corresponding fuzzy output. It is clear that the input-output relation for each unit of fuzzy neural network (FNN) is defined by the extension principle of Zadeh. In this work, a cost function is also defined for the level sets of fuzzy output and fuzzy target. Next a learning algorithm based on the gradient descent method will be defined that can adjust the fuzzy connection weights. Finally, our approach is illustrated by computer simulations on numerical examples. It is worthwhile to mention that application of this method in fluid mechanics has been shown by an example.
    International Journal of Computer Mathematics 09/2014;
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    ABSTRACT: In this paper, we address several open problems concerning pure grammar systems (pGSs) and their controlled versions. More specifically, we prove the following four results. (I) Regular-controlled pGSs having a single component define the family of regular languages. (II) pGSs having two components controlled by infinite regular languages define the family of recursively enumerable languages. (III) Regular-controlled pGSs without any erasing rules define the family of regular languages not containing the empty string. (IV) pGSs define a proper subfamily of the family of regular languages.
    International Journal of Computer Mathematics 08/2014; 91(6):2014.
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    ABSTRACT: In this paper, we consider an optimal control problem of switched systems with a continuous-time inequality constraint. Because of the complexity of this constraint, it is difficult to solve this problem by standard optimization techniques. To overcome this difficulty, the problem is divided into a bi-level optimization problem involving a combination of a continuous-time optimal control problem and a discrete optimization problem. Then, a modified Broyden-Fletcher-Goldfarb-Shanno algorithm and a discrete filled function method is first proposed to solve this bi-level optimization problem. Finally, a numerical example is presented to illustrate the efficiency of our method.
    International Journal of Computer Mathematics 08/2014; 91(8).
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    ABSTRACT: Some localized numerical methods, such as finite element and finite difference methods (FDMs), have encountered difficulties when solving fourth or higher order differential equations. Localized methods, which use radial basis functions, are considered the generalized FDMs and, thus, inherit the similar difficulties when solving higher order differential equations. In this paper, we deal with the use of the localized method of approximate particular solutions (LMAPS), a recently developed localized radial basis function collocation method, in solving two-dimensional biharmonic equation in a bounded region. The technique is based on decoupling the biharmonic problem into two Poisson equations, and then the LMAPS is applied to each Poisson's problem to compute numerical solutions. Furthermore, the influence of the shape parameter and different radial basis functions on the numerical solution is discussed. The effectiveness of the proposed method is demonstrated by solving three examples in both regular and irregular domains.
    International Journal of Computer Mathematics 08/2014; 91(8).
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    ABSTRACT: The conjugate gradient method is one of the most effective methods to solve the unconstrained optimization problems. In this paper, we develop a new three-term conjugate gradient (TTCG) method by applying the Powell symmetrical technique to the Hestenes–Stiefel method. The proposed method satisfies both the sufficient descent property and the conjugacy condition [Inline formula], which do not rely on any line search. Under the standard Wolfe line search, the global convergence of the proposed method is also established. The numerical results also show that the proposed method is very effective and interesting by comparing with other TTCG methods using a classical set of test problems.
    International Journal of Computer Mathematics 08/2014; 91(8).
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    ABSTRACT: In this paper, we propose a trust-region algorithm in association with line search filter technique for solving nonlinear equality constrained programming. At current iteration, a trial step is formed as the sum of a normal step and a tangential step which is generated by trust-region subproblem and the step size is decided by interior backtracking line search together with filter methods. Then, the next iteration is determined. This is different from general trust-region methods in which the next iteration is determined by the ratio of the actual reduction to the predicted reduction. The global convergence analysis for this algorithm is presented under some reasonable assumptions and the preliminary numerical results are reported.
    International Journal of Computer Mathematics 08/2014; 91(8).
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper focuses on a multistep splitting method for a class of nonlinear viscous equations in two spaces, which uses second-order backward differentiation formula (BDF2) combined with approximation factorization for time integration, and second-order centred difference approximation to second derivatives for spatial discretization. By the discrete energy method, it is shown that this splitting method can attain second-order accuracy in both time and space with respect to the discrete L 2- and H 1-norms. Moreover, for improving computational efficiency, we introduce a Richardson extrapolation method and obtain extrapolation solution of order four in both time and space. Numerical experiments illustrate the accuracy and performance of our algorithms.
    International Journal of Computer Mathematics 08/2014; 91(8).
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    ABSTRACT: We consider the problem of interpolating a multivariable function defined on a bounded domain using its traces on parametric hypersurfaces. Our approach is based on the theory of operator polynomial interpolation. We construct the corresponding operator interpolation polynomial for a given function and analyse in detail particular two- and three-dimensional cases. Numerical examples presented in the paper show the flexibility of the proposed approach.
    International Journal of Computer Mathematics 08/2014; 91(8).