2020-04-02T05:13:11Z http://ijm2c.iauctb.ac.ir/?_action=export&rf=summon&issue=112358
2012-12-21
International Journal of Mathematical Modelling & Computations 2228-6225 2228-6225 2012 2 1 (WINTER) DUAL BOUNDARY ELEMENT ANALYSIS OF CRACKED PLATES A. Portela The dual boundary element method is formulated for the analysis of linear elastic cracked plates. The dual boundary integral equations of the method are the displacement and the traction equations. When these equations are simultaneously applied along the crack boundaries, general crack problems can be solved in a single-region formulation, with both crack boundaries discretized with discontinuous boundary elements. The stress intensity factors evaluation is carried out by the J-integral decomposition method which is applied on a circular path, defined around each crack tip. Examples of geometries with edge, and embedded cracks are analyzed. The accuracy and e_ciency of the dual boundary element method and the J-integral make the present formulation ideal for the study of cracked plates.   Dual boundary integral equations Crack modelling Computation of 2012 12 21 1 19 http://ijm2c.iauctb.ac.ir/article_521781_1ffc6dc634575a075111fb4ef91c577d.pdf
2012-12-21
International Journal of Mathematical Modelling & Computations 2228-6225 2228-6225 2012 2 1 (WINTER) HALL AND LON-SLIP EFFECTS ON MAGNETO-MICROPOLAR FLUID WITH COMBINED FORCED AND FREE CONVECTION IN BOUNDARY LAYER FLOW OVER A HORIZONTAL PLATE WITH VISCOUS DISSIPATION G. Deepa N. Kishan In this paper, we study the effects of Hall and ion-slip currents on the steady magneto-micropolar of a viscous incompressible and electrically conducting fluid over a horizontal plate by taking in to account the viscous dissipation effects. By means of similarity solutions, deviation of fundamental equations on the assumption of small magnetic Reynolds number are solved numerically by using quasilinearised first and finite difference method. The effects of various parameters of the problem, e.g. the magnetic parameter, Hall parameter, ion- slip parameter, buoyancy parameter and material parameter and Eckert number are discussed and shown graphically.   Hall effects Ion-slip buoyancy parameter Eckert number finite difference method 2012 12 21 21 33 http://ijm2c.iauctb.ac.ir/article_521782_938833ac8f3c2bd1de05c93d78f5fe78.pdf
2012-12-21
International Journal of Mathematical Modelling & Computations 2228-6225 2228-6225 2012 2 1 (WINTER) APPLICATION OF KRIGING METHOD IN SURROGATE MANAGEMENT FRAMEWORK FOR OPTIMIZATION PROBLEMS B. Azarkhalili M. Rasouli P. Moghadas B. Mehri In this paper, Kriging has been chosen as the method for surrogate construction. The basic idea behind Kriging is to use a weighted linear combination of known function values to predict a function value at a place where it is not known. Kriging attempts to determine the best combination of weights in order to minimize the error in the estimated function value. Because the actual function value is not known, the error is modeled using probability theory and then minimized. The result is a linear system of equations that can be solved to ﬁnd a unique combination of weights for a given point at which interpolation is to be performed.   Surrogate Management Framework Kriging Computational Order convergence Gradient 2012 12 21 35 44 http://ijm2c.iauctb.ac.ir/article_521783_2dcfc23cecf6d197cca235f2805c8bff.pdf
2012-12-21
International Journal of Mathematical Modelling & Computations 2228-6225 2228-6225 2012 2 1 (WINTER) AN ITERATIVE METHOD WITH SIX-ORDER CONVERGENCE FOR SOLVING NONLINEAR EQUATIONS M. Matinfar M. Aminzadeh Modiﬁcation of Newtons method with higher-order convergence is presented. The modiﬁcation of Newtons method is based on Frontinis three-order method. The new method requires two-step per iteration. Analysis of convergence demonstrates that the order of convergence is 6. Some numerical examples illustrate that the algorithm is more efficient and performs better than classical Newtons method and other methods.   Nonline ar equation ite rative metho d Two- step Con- vergence orde r Eﬃc iency index 2012 12 21 45 51 http://ijm2c.iauctb.ac.ir/article_521784_d3e3d98af89b588ee86c9e8c7d45728d.pdf
2012-12-21
International Journal of Mathematical Modelling & Computations 2228-6225 2228-6225 2012 2 1 (WINTER) THE IDENTIFICATION OF EFFICIENCY BY USING FUZZY NUMBERS M. Sanei R. Dehghan A. Mahmoodi Rad In original Data Envelopment Analysis (DEA) models for measuring the relative efficiencies of a set of Decision Making Units (DMUs) using various inputs to produce various outputs are limited to crisp data. To deal with imprecise data, the notion of fuzziness has been introduced. this paper develops a procedure to measure the efficiencies of DMUs with fuzzy observations. The basic idea is to transform a fuzzy DEA model to family of conventional crisp DEA models by applying optimistic, intermediate and pessimistic concepts. A numerical example is given to show the efficiency.   Data envelopment analysis 2012 12 21 53 59 http://ijm2c.iauctb.ac.ir/article_521785_41b84f105f4149405f8bc12552f598e4.pdf
2012-12-21
International Journal of Mathematical Modelling & Computations 2228-6225 2228-6225 2012 2 1 (WINTER) ANALYTICAL-NUMERICAL SOLUTION FOR NONLINEAR INTEGRAL EQUATIONS OF HAMMERSTEIN TYPE J. Rashidinia A. Parsa Using the mean-value theorem for integrals we tried to solved the nonlinear integral equations of Hammerstein type . The mean approach is to obtain an initial guess with unknown coefficients for unknown function y(x). The procedure of this method is so fast and don't need high cpu and complicated programming. The advantages of this method are that we can applied for those integral equations which have not the unique solution too.   Nonlinear integral equations Hammerstein equations mean value 2012 12 21 61 69 http://ijm2c.iauctb.ac.ir/article_521786_239a280f7f33b556a7a21709cc4b1132.pdf
2012-12-21
International Journal of Mathematical Modelling & Computations 2228-6225 2228-6225 2012 2 1 (WINTER) THE RELATION BETWEEN TOPOLOGICAL ORDERING AND ADJACENCY MATRIX IN DIGRAPHS T. Rastad N. Delfan In this paper the properties of node-node adjacency matrix in acyclic digraphs are considered. It is shown that topological ordering and node-node adjacency matrix are closely related. In fact, first the one to one correspondence between upper triangularity of node-node adjacency matrix and existence of directed cycles in digraphs is proved and then with this correspondence other properties of adjacency matrix in acyclic digraphs are presented.   adjacency matrix topological ordering acyclic digraph 2012 12 21 71 75 http://ijm2c.iauctb.ac.ir/article_521787_1ec4d41012f01c65157099257d53db72.pdf
2012-12-21
International Journal of Mathematical Modelling & Computations 2228-6225 2228-6225 2012 2 1 (WINTER) ALTERNATIVE MIXED INTEGER PROGRAMMING FOR FINDING EFFICIENT BCC UNIT M. Toloo Z. Khoshhal Nakhjiry Data Envelopment Analysis (DEA) cannot provide adequate discrimination among efficient decision making units (DMUs). To discriminate these efficient DMUs is an interesting research subject. The purpose of this paper is to develop the mix integer linear model which was proposed by Foroughi (Foroughi A.A. A new mixed integer linear model for selecting the best decision making units in data envelopment analysis. Computers & Industrial Engineering 60 (2011) 550-554) to present new alternative mix integer programming DEA (MIP-DEA) models which can be used to improve discrimination power of DEA and select the most BCC-efficient decision making unit (DMU). We will demonstrate that proposed model is able to select DMU throughout the real data sets.   Data envelopment analysis Mixed Integer Programming eciency common 2012 12 21 77 85 http://ijm2c.iauctb.ac.ir/article_521788_2050f8a85231566500f06ee6053571a0.pdf