ACECR at Tarbiat Modares University Iranian Journal of Mathematical Sciences and Informatics 1735-4463 2008-9473 4 2 2009 11 1 A topology on BCK-algebras via left and right stabilizers 1 8 EN T. Roudabri Y L. Torkzadeh N 10.7508/ijmsi.2009.02.001 In this paper, we use the left(right) stabilizers of a BCKalgebra (X, ;lowast, 0) and produce two basis for two different topologies. Then we show that the generated topological spaces by these basis are Bair, connected, locally connected and separable. Also we study the other properties of these topological spaces. BCK-algebra , basis topological, stabilizers, Bair space, connected space, locally connected and separable space. http://ijmsi.ir/article-1-91-en.html http://ijmsi.ir/article-1-91-en.pdf

ACECR at Tarbiat Modares University Iranian Journal of Mathematical Sciences and Informatics 1735-4463 2008-9473 4 2 2009 11 1 Redefined fuzzy subalgebra (with thresholds) of BCK/BCI-algebras 9 24 EN Arsham Borumand Saeid Y 10.7508/ijmsi.2009.02.002 Using the notion of anti fuzzy points and its besideness to and non-quasi-coincidence with a fuzzy set, new concepts of an anti fuzzy subalgebras in BCK/BCI-algebras are introduced and their inter-relations and related properties are investigated in [3]. The notion of the new fuzzy subalgebra with thresholds are introduced and relationship between this notion and the new fuzzy subalgebra of a BCK/BCI-algebra of [3] are studied. besides to, non-quasi coincident with, (α, β)∗-fuzzy subalgebra, fuzzy subalgebra with thresholds, fuzzifying subalgebra, t-implication-based subalgebra. http://ijmsi.ir/article-1-98-en.html http://ijmsi.ir/article-1-98-en.pdf

ACECR at Tarbiat Modares University Iranian Journal of Mathematical Sciences and Informatics 1735-4463 2008-9473 4 2 2009 11 1 A K-Theoritic Approach to Some C*-Algebras 25 31 EN B. Tabatabaie Shourijeh Y M. Farjood N 10.7508/ijmsi.2009.02.003 In this paper we look at the K-theory of a specific C*-algebra closely related to the irrational rotation algebra. Also it is shown that any automorphism of a C*-algebra A induces group automorphisms of K_{1}(A) amd K_{0}(A) in an obvious way. An interesting problem for any C*-algebra A is to find out whether, given an automorphism of K_{0}(A) and an automorphism of K_{1}(A), we can lift them to an automorphism of A or M_{n}(A) for some positive integer n. C*-algebra, K-theory, Exact group, Crossed Product, and Representation. http://ijmsi.ir/article-1-87-en.html http://ijmsi.ir/article-1-87-en.pdf

ACECR at Tarbiat Modares University Iranian Journal of Mathematical Sciences and Informatics 1735-4463 2008-9473 4 2 2009 11 1 Bank efficiency evaluation using a neural network-DEA method 33 48 EN G. Aslani Y S. H. Momeni-Masuleh N A. Malek N F. Ghorbani N 10.7508/ijmsi.2009.02.004 In the present time, evaluating the performance of banks is one of the important subjects for societies and the bank managers who want to expand the scope of their operation. One of the non-parametric approaches for evaluating efficiency is data envelopment analysis(DEA). By a mathematical programming model, DEA provides an estimation of efficiency surfaces. A major problem faced by DEA is that the frontier calculated by DEA may be slightly distorted if the data is affected by statistical noises. In recent years, using the neural networks is a powerful non-parametric approach for modeling the nonlinear relations in a wide variety of decision making applications. The radial basis function neural networks (RBFNN) have proved significantly beneficial in the evaluation and assessment of complex systems. Clustering is a method by which a large set of data is grouped into clusters of smaller sets of similar data. In this paper, we proposed RBFNN with the K-means clustering method for the efficiency evaluation of a large set of branches for an Iranian bank. This approach leads to an appropriate classification of branches. The results are compared with the conventional DEA results. It is shown that, using the hybrid learning method, the weights of the neural network are convergent. Data envelopment analysis, Neural networks, Efficiency, Multilayered perceptron, Radial basis function, K-means clustering method. http://ijmsi.ir/article-1-89-en.html http://ijmsi.ir/article-1-89-en.pdf

ACECR at Tarbiat Modares University Iranian Journal of Mathematical Sciences and Informatics 1735-4463 2008-9473 4 2 2009 11 1 A study of Nilpotent groups through right transversals 49 54 EN A. M. Tripathi Y Nirbhay Mathur N Swapnil Srivastava N 10.7508/ijmsi.2009.02.005 In group theory nilpotency of a group has a great importance. In this paper we have studied some concept of nilpotency through right transversals. We have also studied prime power groups and frattini subgroups through right transversals. Nilpotent group, Right transversal, Frattini subgroup, C-groupoid. http://ijmsi.ir/article-1-86-en.html http://ijmsi.ir/article-1-86-en.pdf

ACECR at Tarbiat Modares University Iranian Journal of Mathematical Sciences and Informatics 1735-4463 2008-9473 4 2 2009 11 1 Generalized Jacobian and Discrete Logarithm Problem on Elliptic Curves 55 64 EN H. Daghigh Y M. Bahramian N 10.7508/ijmsi.2009.02.006 Let E be an elliptic curve over the finite field F_{q}, P a point in E(F_{q}) of order n, and Q a point in the group generated by P. The discrete logarithm problem on E is to find the number k such that Q = kP. In this paper we reduce the discrete logarithm problem on E[n] to the discrete logarithm on the group F*_{q} , the multiplicative group of nonzero elements of Fq, in the case where n | q ;minus 1, using generalized jacobian of E. Elliptic Curve, Discrete Logarithm Problem, Generalized Jacobian. http://ijmsi.ir/article-1-88-en.html http://ijmsi.ir/article-1-88-en.pdf

ACECR at Tarbiat Modares University Iranian Journal of Mathematical Sciences and Informatics 1735-4463 2008-9473 4 2 2009 11 1 Qualitative Properties and Existence of Solutions for a Generalized Fisher-like Equation 65 81 EN Smail Djebali Y Otared Kavian N Toufik Moussaoui N 10.7508/ijmsi.2009.02.007 This paper is devoted to the study of an eigenvalue second order differential equation, supplied with homogenous Dirichlet conditions and set on the real line. In the linear case, the equation arises in the study of a reaction-diffusion system involved in disease propagation throughout a given population. Under some relations upon the real parameters and coefficients, we present some existence and nonexistence results. We use a variational method and fixed point arguments. Linear and sub-linear ODEs, Variational Method, Fixed point Theorems, Compactness Criterion. http://ijmsi.ir/article-1-90-en.html http://ijmsi.ir/article-1-90-en.pdf