On two theorems about operators in Banach lattices
Author: B. Aqzzouz / R. Nouira / L. Zraoula
Abstract: We give another original and easy proof of a theorem of Aliprantis and Burkhinshaw about domination problem of compact operators and a short proof of a theorem of Zaanen about the duality problem of AM-compact operators.
Abstract: Considering the bivariate Schurer-Stancu approximation formula, a new cubature formula is established, that will be called the Schurer-Stancu cubature formula. Its coefficients are determined and an upper bound estimation for the remainder term is established. As particular cases follow the cubature formulas of Schurer, Stancu and respectively Bernstein.
On a family of first order difference inequalities used in the iterative approximation of fixed points
Author: Vasile Berinde
Abstract: Several first order difference inequalities which are intensively used in proving convergence theorems for various fixed point iteration procedures are unified and detailedly demonstrated. In terms of the difference equations terminology, the obtained results basically show that the zero solution of these difference inequalities is globally asymptotically stable. Some new more general conditions under which the zero solution
of these difference inequalities is globally asymptotically stable, which extends and includes corresponding related results obtained in recent literature, are also given.
The efficiency of the image subband coding algorithms based on zerotrees
Author: Ovidiu Cosma
Abstract: EZW (Embedded image coding using Zerotrees of Wavelet coef?cients) and SPIHT (Set Partitioning in Hierarchical Trees) are two of the best known progressive coding algorithms for the subbands of images. A progressive image-coding algorithm has to include at each pass, information about the magnitude of the significant coefficients, and their position in the two-dimensional array of the transform. This article evaluates the efficiency of those algorithms, expressed through the compactness of the position information.
Self-dual designs and their binary codes obtained from the group PSL2(13)
Author: R. Kahkeshani / M. R. Darafsheh / A. Iranmanesh
Abstract: We examine self-dual designs and their binary codes constructed from the primitive permutation representations of the group PSL2(13) of degrees 78 and 91. We show that all of these designs and codes have PSL2(13) or PSL2(13) : 2 as the full automorphism group.
A possible visual image of the extended monogenous function
Author: Lidia Elena Kozma / Gheorghe Ardelean
Abstract: Themonogenous functions defined on R4 ! R4 were introduced by G.C.Moisil. Ifwe start frommonogenous functions on a quaternion, through
particularization we only find the monogenity condition @w
@z = 0 for a functionw = f(z) : C ! C: In this article the notion of monogenity is
extended from the common complex analysis over to the quaternion functions of two variables, of the following aspect:
K = x + iy + ju(x; y) + kv(x; y) = z + jw(x; y) (0.1)
and we have visualized the surfaces (S) attached to this quaternion
(S) r = iy + ju(x; y) + kv(x; y) (0.2)
in monogenity conditions. A few surfaces attached to some elementary monogenous functions have been visualized.
Abstract: We consider a selfmap T on union of p subsets (p 1), fAigp
i=1 of ametric space into itself, such that T(Ai) Ai+1; i = 1; 2; : : : ; p(Ap+1 = A1),
where the contractive assumptions are restricted to pairs (x; y) 2 Ai Ai+1. We give fixed point theorems for Ciric-Reich-Rus mappings under
cyclical considerations and fixed point results for some generalizations of this contractive type mappings.
On partially ordered n-semigroups and (n;m)-semirings
Author: Adina Pop / Maria Sânziana Pop
Abstract: In this paper we generalize for n- semigroups and (n;m)-presemirings the notions of partially ordered and positively ordered semigroups and semirings. We note that the partially ordered n-groups and (n;m)-rings are introduced by G. Crombez, Abh. Math. Sem. Univ. Hamburg, 39 (1973), 141-146.
Simple considerations on the deflection angle of light in General Relativity
Author: Cristian Eduard Rusu
Abstract: The purpose of this paper is to provide an easy to approach yet complete discussion on the relativistic de?ection of light. First, we obtain the formula for the deflection of light in the Friedmann-Roberson-Walker metric. We then show this result is equivalent to the equation for the path of a light ray in a medium with a certain effective index of refraction. Finally we compare the angle of deflection in the potential of a point-like mass with the one that might be obtained via simple classical-limit considerations.
RESTful multilayer architectures for Web-based learning systems
Author: Cezar Toader
Abstract: This paper refers to important aspects of the evolution of Web-based Learning Systems architecture, according to the evolution of the Web itself. The Web developed through creation of new levels of abstracting, while a special importance to scalability and adaptability was given. Due to a growing importance given to resource-orientedWeb services, in the last years, we bring into discussion the principle of organizing the algorithmic resources in multi-level hierarchy and the principle of uniform access to resources. Finally, in order to implement these principles, the author promotes an architectural model of Web applications, called here RESTful Multilayer Architecture.