فهرست مطالب

بین المللی محاسبات و مدل سازی ریاضی - سال پنجم شماره 1 (Winter 2015)

مجله بین المللی محاسبات و مدل سازی ریاضی
سال پنجم شماره 1 (Winter 2015)

  • تاریخ انتشار: 1394/03/03
  • تعداد عناوین: 8
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  • Reza Jalilian, J. Rashidinia, K. Farjian, H. Jalilian Page 1
    A Class of new methods based on a septic non-polynomial spline function for the numerical solution of problems in calculus of variations is presented. The local truncation errors and the methods of order 2th، 4th، 6th، 8th، 10th، and 12th، are obtained. The inverse of some band matrixes are obtained which are required in proving the convergence analysis of the presented method. Convergence analysis of these methods is discussed. Numerical results are given to illustrate.
    Keywords: Two, point boundary value problem, Non, polynomial spline, Convergence analysis, Calculus of variation
  • Godwin Amechi Okeke, Johnson O. Olaleru Page 15
    We study the convergence of the modified Noor iterative scheme for the class of asymptotically pseudocontractive mappings in the intermediate sense which is not necessarily Lipschitzian. Our results improves, extends and unifies the results of Schu [23] and Qin {\it et al.} [25].
    Keywords: Asymptotically pseudocontractive mapping in the intermediate sense, weak, strong convergence theorems, the modified Noor iterative scheme
  • Veena Goswami, P. Vijaya Laxmi Page 29
    This paper analyzes a controllable discrete-time machine repair problem with L operating machines and two repairmen. The number of working servers can be adjusted depending on the number of failed machines in the system one at a time at machine''s failure or at service completion epochs. Analytical closed-form solutions of the stationary probabilities of the number of failed machines in the system are obtained. We develop the total expected cost function per machine per unit time and obtain the optimal operating policy and the optimal service rate at minimum cost using quadratic ¯t search method and simulated annealing method. Various performance measures along with numerical results to illustrate the in uence of various parameters on the bu®er behavior are also presented.
    Keywords: Discrete, time, Triadic policy, Machine, repair, Cost, Quadratic ¯t search method, Queue
  • Farhad Khaksar Haghani Page 41
    In this note, we propose a modification of Steffensen''s method with some free parameters. These parameters are then be used for further acceleration via the concept of with memorization. In this way, we derive a fast Steffensen-type method with memory for solving nonlinear equations. Numerical results are also given to support the underlying theory of the article.
    Keywords: Steffensen's method, root, order, with memory
  • G. Ayyappan, K. Sathiya Page 49
    A single server provides service to all arriving customers with service time following general distribution. After every service completion the server has the option to leave for phase one vacation of random length with probability p or continue to stay in the system with probability 1 􀀀 p. As soon as the completion of phase one vacation, the server may take phase two vacation with probability q or to remain in the system with probability 1􀀀q, after phase two vacation again the server has the option to take phase three vacation with probability r or to remain in the system with probability 1 􀀀 r. The vacation times are assumed to be general. The server is interrupted at random and the duration of attending interruption follows exponential distribution. Also we assume, the customer whose service is interrupted goes back to the head of the queue where the arrivals are Poisson. The time dependent probability generating functions have been obtained in terms of their Laplace transforms and the corresponding steady state results have been obtained explicitly. Also the mean number of customers in the queue and system and the waiting time in the queue and system are also derived. Particular cases and numerical results are discussed.
  • Amir Sadeghi Page 69
    The computation of the inverse roots of matrices arises in evaluating non-symmetric eigenvalue problems, solving nonlinear matrix equations, computing some matrix functions, control theory and several other areas of applications. It is possible to approximate the matrix inverse pth roots by exploiting a specialized version of New- ton''s method, but previous researchers have mentioned that some iterations have poor convergence and stability properties. In this work, a stable recursive technique to evaluate an inverse pth root of a given matrix is presented. The scheme is analyzed and its properties are investigated. Computational experiments are also performed to illustrate the strengths and weaknesses of the proposed method.
    Keywords: Inverse matrix pth roots, Coupled Newton's iterations, Convergency, Stability
  • Bahman Ghazanfari, Parvin Ebrahimi Page 81
    In this paper, the differential transformation method (DTM) was applied to solve fuzzy fractional heat equations. The elementary properties of this method were given. The approximate and exact solutions of these equations were calculated in the form of series with easily computable terms. The proposed method was also illustrated by some examples. The results revealed that DTM is a highly effective scheme for obtaining approximate analytical solutions of fuzzy fractional heat equations.
    Keywords: fuzzy fractional heat, differential transformation method, fuzzy Caputo's derivative
  • Mansour Saraj, Nima Safaei Page 91
    This paper presents a Taylor series approach for solving linear fractional de- centralized bi-level multi-objective decision-making (LFDBL-MODM) problems with a single decision maker at the upper level and multiple decision makers at the lower level. In the proposed approach, the membership functions associated with each objective(s) of the level(s) of LFDBL-MODM are transformed by using a Taylor series and then they are unified. On using the Kuhn-Tucker conditions, the problem is finally reduced to a single objective. Numerical example is given in order to illustrate the efficiency and superiority of the proposed approach.
    Keywords: Bilevel programming, Fractional programming, Fuzzy Programming, Kuhn, Tucker conditions, Taylor series