http://www.hindawi.comThe latest articles from Hindawi Publishing Corporation© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/527106We obtain new characterizations of open maps in terms of closures, of closed maps in terms of interiors, and of continuous maps in terms of interiors. Further open (closed) onto maps f:X→Y are described in terms of images under f of certain closed (open) sets in X. Continuity of (onto) maps is also characterized in terms of saturated sets.Navpreet Singh Noorie and Rajni Bala© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/651910This paper concerns the Stokes flow of an incompressible viscous fluid past a swarm of porous nanocylindrical particles enclosing a solid cylindrical core with Kuwabara boundary condition. An aggregate of porous nanocylindrical particles is considered as a hydro-dynamically equivalent to a solid cylindrical core with concentric porous cylindrical shell. The Brinkman equation inside the porous cylindrical shell and the Stokes equation outside the porous cylindrical shell in their stream function formulations are used. Explicit expressions for the stream functions in both regions have been investigated. The drag force acting at each nanoporous cylindrical particle in a cell is evaluated. Also, we solved the same problem by using Happel boundary condition on the hypothetical cell. In certain limiting cases, drag force converges to pre-existing analytical results, such as the drag on a porous circular cylinder and the drag on a solid cylinder in Kuwabara's cell or Happel's cell. Representative results are then discussed and compared for both cases and presented in graphical form by using Mathematica software.Satya Deo and Pramod Kumar Yadav© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/753632Suffcient conditions, necessary conditions for faster convergent infinite series, faster τ-convergent infinite series are studied. The faster convergence of infinite series of Kummer's type is proved.Dušan Holý, Ladislav Matejíčka, and Ľudovít Pinda© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/196326We study the farthest point mapping in a p-normed space X in virtue of subdifferential of r(x)=sup{‖x−z‖p:z∈M}, where M is a weakly sequentially compact subset of X. We show that the set of all points in X which have farthest point in M contains a dense Gδ subset of X.S. Hejazian, A. Niknam, and S. Shadkam© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/165089This study shows that a refinement of the Hilbert inequality for double series can be established by introducing a real function u(x) and a parameter λ. In particular, some sharp results of the classical Hilbert inequality are obtained by means of a sharpening of the Cauchy inequality. As applications, some refinements of both the Fejer-Riesz inequality and Hardy inequality in Hp function are given.Zhou Yu and Gao Mingzhe© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/496720In this article, we study the relationship between left (right) zip property of R and skew polynomial extension over R, using the skew versions of Armendariz rings.Wagner Cortes© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/783041We associate a covering relation to the usual order relation defined in the set of all idempotent endomorphisms (projections) of a finite-dimensional vector space. A characterization is given of it. This characterization makes this order an order verifying the Jordan-Dedekind chain condition. We give also a property for certain finite families of this order. More precisely, the family of parts intervening in the linear representation of diagonalizable endomorphism, that is, the orthogonal families forming a decomposition of the identity endomorphism.M. Yazi© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/362409We prove that if A and B∗ are subnormal operators and X is a bounded linear operator such that AX−XB is a Hilbert-Schmidt operator, then f(A)X−Xf(B) is also a Hilbert-Schmidt operator and ‖f(A)X−Xf(B)‖2≤L‖AX−XB‖2 for f belongs to a certain class of functions. Furthermore, we investigate the similar problem in the case that S, T are hyponormal operators and X∈ℒ(ℋ) is such that SX−XT belongs to a norm ideal (J,‖⋅‖J), and we prove that f(S)X−Xf(T)∈J and ‖f(S)X−Xf(T)‖J≤C‖SX−XT‖J for f being in a certain class of functions.Vasile Lauric© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/794181We investigate the integral representation of infinite sums involving the reciprocals of triple binomial coefficients. We also recover some wellknown properties of ζ(3) and extend the range of results given by other authors.A. Sofo© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/630589We establish the convergence of Krasnoselskij iteration for various classes of non-Lipschitzian operators.Ştefan M. Şoltuz and B. E. Rhoades© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/576061Let R be a commutative ring and S a finite locally inverse semigroup. It is proved that the semigroup algebra R[S] is isomorphic to the direct product of Munn algebras ℳ(R[GJ],mJ,nJ;PJ) with J∈S/𝒥, where mJ is the number of ℛ-classes in J, nJ the number of ℒ-classes in J, and GJ a maximum subgroup of J. As applications, we obtain the sufficient and necessary conditions for the semigroup algebra of a finite locally inverse semigroup to be semisimple.Xiaojiang Guo© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/318582We use the familiar convolution structure of analytic functions to introduce two new subclasses of multivalently analytic functions of complex order, and prove several inclusion relationships associated with the (n,δ)-neighborhoods for these subclasses. Some interesting consequences of these results are also pointed out.J. K. Prajapat and R. K. Raina© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/436570We introduce definitions of fuzzy inverse compactness, fuzzy inverse countable compactness, and fuzzy inverse Lindelöfness on arbitrary L-fuzzy sets in L-fuzzy topological spaces. We prove that the proposed definitions are good extensions of the corresponding concepts in ordinary topology and obtain different characterizations of fuzzy inverse compactness.Halis Aygün, A. Arzu Bural, and S. R. T. Kudri© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/520698For λ>−1 and μ≥0, we consider a liner operator Iλμ on the class 𝒜 of analytic functions in the unit disk defined by the convolution (fμ)(−1)∗f(z), where fμ=(1−μ)z2F1(a,b,c;z)+μz(z2F1(a,b,c;z))', and introduce a certain new subclass of 𝒜 using this operator. Several interesting properties of these classes are obtained.K. Al-Shaqsi and M. Darus© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/495075 We obtain two theorems to determine the error bound between input periodic signals and processed output signals, whenever signals belong to Hω-space and as a processor we have taken (C,1)(E,1)-mean and generalized an early result of Lal and Yadav in (2001).Tikam Singh and Pravin Mahajan© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/283846We completely solve the generalized Fermat problem: given a triangle P1, P2, P3 and three positive numbers λ1, λ2, λ3, find a point P for which the sum λ1P1P+λ2P2P+λ3P3P is minimal. We show that the point always exists and is unique, and indicate necessary and sufficient conditions for the point to lie inside the triangle. We provide geometric interpretations of the conditions and briefly indicate a connection with dynamical systems.Yujin Shen and Juan Tolosa© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/423596 A KKM space is an abstract convex space satisfying the KKM principle. We obtain variants of the KKM principle for KKM spaces related to weakly KKM maps and indicate some applications of them. These results properly generalize the corresponding ones in G-convex spaces and ϕA-spaces (X,D;{ϕA}A∈〈D〉). Consequently, results by Balaj 2004, Liu 1991, and Tang et al. 2007 can be properly generalized and unified.Sehie Park© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/145683We characterize π-images of locally separable metric spaces by means of covers having π-property. As its application, we obtain characterizations of compact-covering (sequence-covering, pseudo-sequence-covering, and sequentially quotient) π-images of locally sparable metric spaces.Tran Van An and Nguyen Van Dung© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/153280By making use of the fractional differential operator Ωzλ due to Owa and Srivastava, a class of analytic functions ℛλ(α,ρ)    (0≤ρ≤1,  0≤λ<1,    |α|<π/2) is introduced. The sharp bound for the nonlinear functional |a2a4−a32| is found. Several basic properties such as inclusion, subordination, integral transform, Hadamard product are also studied.A. K. Mishra and P. Gochhayat© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/490316Let N be a 3-prime 2-torsion-free zero-symmetric left near-ring with multiplicative center Z. We prove that if N admits a nonzero generalized derivation f such that f(N)⊆Z, then N is a commutative ring. We also discuss some related properties.Howard E. Bell© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/297508It is shown that some new extensions of Hilbert's integral inequality with parameter λ(λ>1/2) can be established by introducing a proper weight function. In particular, when λ=1, a refinement of Hilbert's integral inequality is obtained. As applications, some new extensions of Widder's inequality and Hardy-Littlewood's inequality are given.He Leping, Gao Mingzhe, and Zhou Yu© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/362068There are five equivalence relations known as Green's relations definable on any semigroup or monoid, that is, on any algebra with a binary operation which is associative. In this paper, we examine whether Green's relations can be defined on algebras of any type τ. Some sort of (super-)associativity is needed for such definitions to work, and we consider algebras which are clones of terms of type τ, where the clone axioms including superassociativity hold. This allows us to define for any variety V of type τ two Green's-like relations ℒV and ℛV on the term clone of type τ. We prove a number of properties of these two relations, and describe their behaviour when V is a variety of semigroups.K. Denecke and S. L. Wismath© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/741609By a near-ring we mean a right near-ring. J0r, the right Jacobson radical of type 0, was introduced for near-rings by the first and second authors. In this paper properties of the radical J0r are studied. It is shown that J0r is a Kurosh-Amitsur radical (KA-radical) in the variety of all near-rings R, in which the constant part Rc of R is an ideal of R. So unlike the left Jacobson radicals of types 0 and 1 of near-rings, J0r is a KA-radical in the class of all zero-symmetric near-rings. J0r is not s-hereditary and hence not an ideal-hereditary radical in the class of all zero-symmetric near-rings.Ravi Srinivasa Rao, K. Siva Prasad, and T. Srinivas© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/756834We introduce the space Sω1,ω2 of all C∞ functions ϕ such that sup|α|≤m‖ekω1∂αϕ‖∞ and sup|α|≤m‖ekω2∂αϕ^‖∞ are finite for all k∈ℕ0, α∈ℕ0n, where ω1 and ω2 are two weights satisfying the classical Beurling conditions. Moreover, we give a topological characterization of the space Sω1,ω2 without conditions on the derivatives. For functionals in the dual space Sω1,ω2′, we prove a structure theorem by using the classical Riesz representation thoerem.Hamed M. Obiedat, Wasfi A. Shatanawi, and Mohd M. Yasein© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/632518We give the explicit multiplication law of the Lie supergroups for which the base manifold is a 3-dimensional Lie group and whose underlying Lie superalgebra g=g0⊕g1which satisfies g1=g0, g0 acts on g1 via the adjoint representation and g0 has a 2-dimensional derived ideal.I. Hernández and R. Peniche© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/638251The purpose of the present paper is to derive a subordination result for functions in the class Hn*(α,λ,b) of normalized analytic functions in the open unit disk U. A number of interesting applications of the subordination result are also considered.A. A. Attiya, Nak Eun Cho, and M. A. Kutbi© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/468583We provide a process to extend any bipartite diametrical graph of diameter 4 to an S-graph of the same diameter and partite sets. For a bipartite diametrical graph of diameter 4 and partite sets U and W, where 2m=|U|≤|W|, we prove that 2m is a sharp upper bound of |W| and construct an S-graph G(2m,2m) in which this upper bound is attained, this graph can be viewed as a generalization of the Rhombic Dodecahedron. Then we show that for any m≥2, the graph G(2m,2m) is the unique (up to isomorphism) bipartite diametrical graph of diameter 4 and partite sets of cardinalities 2m and 2m, and hence in particular, for m=3, the graph G(6,8) which is just the Rhombic Dodecahedron is the unique (up to isomorphism) bipartite diametrical graph of such a diameter and cardinalities of partite sets. Thus we complete a characterization of S-graphs of diameter 4 and cardinality of the smaller partite set not exceeding 6. We prove that the neighborhoods of vertices of the larger partite set of G(2m,2m) form a matroid whose basis graph is the hypercube Qm. We prove that any S-graph of diameter 4 is bipartite self complementary, thus in particular G(2m,2m). Finally, we study some additional properties of G(2m,2m) concerning the order of its automorphism group, girth, domination number, and when being Eulerian.Salah Al-Addasi and Hasan Al-Ezeh© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/163580The purpose of this paper is to ensure the existence of fixed points for multivalued nonexpansive weakly inward nonself-mappings in uniformly convex metric spaces. This extends a result of Lim (1980) in Banach spaces. All results of Dhompongsa et al. (2005) and Chaoha and Phon-on (2006) are also extended.A. Kaewcharoen and B. Panyanak© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/798317The purpose of this paper is to study some submanifolds and Riemannian submersions on an f-Kenmotsu manifold. The stability of a ϕ-holomorphic map from a compact f-Kenmotsu manifold to a Kählerian manifold is proven.Vittorio Mangione© 2008, Hindawi Publishing Corporation. All rights reserved.http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/386468Our main purpose is to develop the theory of existence of pseudo-superinvolutions of the first kind on finite dimensional central simple associative superalgebras over K, where K is a field of characteristic not 2. We try to show which kind of finite dimensional central simple associative superalgebras have a pseudo-superinvolution of the first kind. We will show that a division superalgebra 𝒟 over a field K of characteristic not 2 of even type has pseudo-superinvolution (i.e., K-antiautomorphism J such that (dδ)J2=(−1)δdδ) of the first kind if and only if 𝒟 is of order 2 in the Brauer-Wall group BW(K). We will also show that a division superalgebra 𝒟 of odd type over a field K of characteristic not 2 has a pseudo-superinvolution of the first kind if and only if −1∈K, and 𝒟 is of order 2 in the Brauer-Wall group BW(K). Finally, we study the existence of pseudo-superinvolutions on central simple superalgebras 𝒜=Mp+q(𝒟0).Ameer Jaber© 2008, Hindawi Publishing Corporation. All rights reserved.