Semnan UniversityInternational Journal of Nonlinear Analysis and Applications2008-682251 (Special Issue)20140101Arens-irregularity of tensor product of Banach algebras1811010.22075/ijnaa.2014.110ENT.YazdanpanahDepartment of Mathematics, Persian Gulf University, Boushehr, 75168, IranR.GharibiDepartment of Mathematics, Persian Gulf University, Boushehr, 75168, IranJournal Article20140217We introduce Banach algebras arising from tensor norms. By these Banach algebras, we make Arens regular Banach algebras such that $alpha$ the tensor product becomes irregular, where $alpha$ is tensor norm. We illustrate injective tensor product, does not preserve bounded approximate identity and it is not algebra norm.Semnan UniversityInternational Journal of Nonlinear Analysis and Applications2008-682251 (Special Issue)20140101Certain subalgebras of Lipschitz algebras of infinitely differentiable functions and their maximal ideal spaces92211110.22075/ijnaa.2014.111END.AlimohammadiDepartment of Mathematics, Faculty of Science, Arak University, P. O. Box: 38156-8-8349, Arak, Iran.F.NezamabadiDepartment of Mathematics, Faculty of Science, Arak University, P. O. Box: 38156-8-8349, Arak, Iran.Journal Article20140217We study an interesting class of Banach function algebras of infinitely differentiable functions on perfect, compact plane sets. These algebras were introduced by Honary and Mahyar in 1999, called Lipschitz algebras of infinitely differentiable functions and denoted by $Lip(X,M, alpha)$, where $X$ is a perfect, compact plane set, $M ={M_n}_{n=0}^infty$ is a sequence of positive numbers such that $M_0 = 1$ and $frac{(m+n)!}{M_{m+n}}leq(frac{m!}{M_m})(frac{n!}{M_n})$, for $m, n inmathbb{N} cup{0}$ and $alphain (0, 1]$. Let $d =lim sup(frac{n!}{M_n})^{frac{1}{n}}$ and $X_d ={z inmathbb{C} : dist(z,X)leq d}$. Let $Lip_{P,d}(X,M, alpha)$ [$Lip_{R,d}(X,M alpha)$] be the subalgebra of all $f in Lip(X,M,alpha)$ that can be approximated by the restriction to $X_d$ of polynomials [rational functions with poles $X_d$]. We show that the maximal ideal space of $Lip_{P,d}(X,M, alpha)$ is $widehat{X_d}$, the polynomially convex hull of $X_d$, and the maximal ideal space of $Lip_{R,d}(X,M alpha)$ is $X_d$, for certain compact plane sets. Using some formulae from combinatorial analysis, we find the maximal ideal space of certain subalgebras of Lipschitz algebras of infinitely differentiable functions.Semnan UniversityInternational Journal of Nonlinear Analysis and Applications2008-682251 (Special Issue)20140101Ternary $(sigma,tau,xi)$-derivations on Banach ternary algebras233511210.22075/ijnaa.2014.112ENM.Eshaghi GordjiDepartment of Mathematics, Semnan University, P. O. Box 35195-363, Semnan, Iran.F.FarrokhzadDepartment of Mathematics, Shahid Beheshti University, Tehran, Iran.S.A.R.HosseiniounDepartment of Mathematical Sciences, University of Arkansas, Fayetteville, Arkansas 72701, USAJournal Article20140219Let $A$ be a Banach ternary algebra over a scalar field $mathbb{R}$ or $mathbb{C}$ and $X$ be a Banach ternary $A$-module. Let $sigma, tau$ and $xi$ be linear mappings on $A$, a linear mapping $D : (A,[ ]_A) to (X, [ ]_X)$ is called a ternary $(sigma,tau,xi)$-derivation, if<br />$$D([xyz]_A) = [D(x)tau(y)xi(z)]_X + [sigma(x)D(y)xi(z)]_X + [sigma(x)tau(y)D(z)]_X$$<br />for all $x,y, z in A$. In this paper, we investigate ternary $(sigma,tau,xi)$-derivation on Banach ternary algebras, associated with the following functional equation<br />$$f(frac{x + y + z}{4}) + f(frac{3x - y - 4z}{4}) + f(frac{4x + 3z}{4}) = 2f(x).$$<br />Moreover, we prove the generalized Ulam-Hyers stability of ternary $(sigma,tau,xi)$-derivations on Banach ternary algebras.Semnan UniversityInternational Journal of Nonlinear Analysis and Applications2008-682251 (Special Issue)20140101Contractive maps in Mustafa-Sims metric spaces365311310.22075/ijnaa.2014.113ENM.Turinici"A. Myller" Mathematical Seminar, "A. I. Cuza" University, 700506 Iasi, RomaniaJournal Article20140219The fixed point results in Mustafa-Sims metrical structures obtained by Karapinar and Agarwal [Fixed Point Th. Appl., 2013, 2013:154] is deductible from a corresponding one stated in terms of anticipative contractions over the associated (standard) metric space.Semnan UniversityInternational Journal of Nonlinear Analysis and Applications2008-682251 (Special Issue)20140101Tripled partially ordered sets546311410.22075/ijnaa.2014.114ENM.EshaghiDepartment of Mathematics, Semnan University, P. O. Box 35195-363, Semnan, IranA.JabbariDepartment of Mathematics, Ardabil Branch, Islamic Azad University, Ardabil, IranS.MohseniDepartment of Mathematics, Faculty of Mathematical Sciences, University of Mazandaran, Babolsar, Iran.Journal Article20140219In this paper, we introduce tripled partially ordered sets and monotone functions on tripled partially ordered sets. Some basic properties on these new defined sets are studied and some examples for clarifying are given.Semnan UniversityInternational Journal of Nonlinear Analysis and Applications2008-682251 (Special Issue)20140101A fixed point result for a new class of set-valued contractions647011510.22075/ijnaa.2014.115ENA.Sadeghi HafjejaniDepartment of Mathematics, University of Shahrekord,
Shahrekord, 88186-34141, Iran.A.Amini HarandiDepartment of Mathematics, University of Shahrekord,
Shahrekord, 88186-34141, Iran.Journal Article20140220In this paper, we introduce a new class of set-valued contractions and obtain a fixed point theorem for such mappings in complete metric spaces. Our main result generalizes and improves many well-known fixed point theorems in the literature.Semnan UniversityInternational Journal of Nonlinear Analysis and Applications2008-682251 (Special Issue)20140101On a more accurate multiple Hilbert-type inequality717911610.22075/ijnaa.2014.116ENQ.HuangDepartment of Mathematics, Guangdong University of Education, Guangzhou, Guangdong 510303, P. R. ChinaB.YangDepartment of Mathematics, Guangdong University of Education, Guangzhou, Guangdong 510303, P. R. ChinaJournal Article20140220By using Euler-Maclaurin's summation formula and the way of real analysis, a more accurate multiple Hilbert-type inequality and the equivalent form are given. We also prove that the same constant factor in the equivalent inequalities is the best possible.Semnan UniversityInternational Journal of Nonlinear Analysis and Applications2008-682251 (Special Issue)20140101A multidimensional discrete Hilbert-type inequality808811710.22075/ijnaa.2014.117ENB.YangDepartment of Mathematics, Guangdong University of Education, Guangzhou, Guangdong 510303, P. R. China.Journal Article20140220In this paper, by using the way of weight coefficients and technique of real analysis, a multidimensional discrete Hilbert-type inequality with the best possible constant factor is given. The equivalent form, the operator expression with the norm are considered.Semnan UniversityInternational Journal of Nonlinear Analysis and Applications2008-682251 (Special Issue)20140101A companion of Ostrowski's inequality for functions of bounded variation and applications899711810.22075/ijnaa.2014.118ENS.S.DragomirSchool of Computational & Applied Mathematics, University of the Witwatersrand, Private Bag 3, Johannesburg 2050,
South Africa.Journal Article20140220A companion of Ostrowski's inequality for functions of bounded variation and applications are given.Semnan UniversityInternational Journal of Nonlinear Analysis and Applications2008-682251 (Special Issue)20140101Some new extensions of Hardy`s inequality9810911910.22075/ijnaa.2014.119ENA.R.MoazzenDepartment of Mathematics, Velayat University, Iranshahr, Iran.R.LashkaripourDepartment of Mathematics, University of Sistan and Baluchestan, Zahedan, Iran.Journal Article20140220In this study, by a non-negative homogeneous kernel k we prove some extensions of Hardy's inequality in two and three dimensions