ACECR at Tarbiat Modares University
Iranian Journal of Mathematical Sciences and Informatics
1735-4463
5
2
2010
11
1
The System of Vector Variational-like Inequalities with Weakly Relaxed ${eta_gamma-alpha_gamma}_{gamma inGamma}$ Pseudomonotone Mappings in Banach Spaces
1
11
EN
M.
Abbasi
Kh.
Pourbarat
In this paper, we introduce two concepts of weakly relaxed ${eta_gamma-alpha_gamma}_{gamma in Gamma}$ pseudomonotone and demipseudomonotone mappings in Banach spaces. Then we obtain some results of the solutions existence for a system of vector variational-like inequalities with weakly relaxed ${eta_gamma-alpha_gamma}_{gamma in Gamma}$ pseudomonotone and demipseudomonotone mappings in reflexive Banach spaces. Finally we show that our results improve and extend some corresponding results of Ref [6].
ACECR at Tarbiat Modares University
Iranian Journal of Mathematical Sciences and Informatics
1735-4463
5
2
2010
11
1
Quotient BCI-algebras induced by pseudo-valuations
13
24
EN
Shokoofeh
Ghorbani
In this paper, we study pseudo-valuations on a BCI-algebra and obtain some related results. The relation between pseudo-valuations and ideals is investigated. We use a pseudo-metric induced by a pseudovaluation to introduce a congruence relation on a BCI-algebra. We define the quotient algebra induced by this relation and prove that it is also a BCI-algebra and study its properties.
ACECR at Tarbiat Modares University
Iranian Journal of Mathematical Sciences and Informatics
1735-4463
5
2
2010
11
1
Fixed Point of $T_{F}$ − contractive Single-valued Mappings
25
32
EN
Sirous
Moradi
Arezoo
Beiranvand
In this paper, we study the existence of fixed points for mappings defined on complete metric space (X, d) satisfying a general contractive inequality depended on another function. This conditions is analogous of Banach conditions and general contraction condition of integral type.
ACECR at Tarbiat Modares University
Iranian Journal of Mathematical Sciences and Informatics
1735-4463
5
2
2010
11
1
On Conditional Applications of Matrix Variate Normal Distribution
33
43
EN
Anis
Iranmanesh
M.
Arashi
S. M. M.
Tabatabaey
In this paper, by conditioning on the matrix variate normal distribution (MVND) the construction of the matrix t-type family is considered, thus providing a new perspective of this family. Some important statistical characteristics are given. The presented t-type family is an extension to the work of Dickey [8]. A Bayes estimator for the column covariance matrix ;Sigma of MVND is derived under Kullback Leibler divergence loss (KLDL). Further an application of the proposed result is given in the Bayesian context of the multivariate linear model. It is illustrated that the Bayes estimators of coefficient matrix under both SEL and KLDL are identical.
ACECR at Tarbiat Modares University
Iranian Journal of Mathematical Sciences and Informatics
1735-4463
5
2
2010
11
1
On the Pixel Expansion of Hypergraph Access Structures in Visual Cryptography Schemes
45
54
EN
Abbas
Cheraghi
In a visual cryptography scheme, a secret image is encoded into n shares, in the form of transparencies. The shares are then distributed to n participants. Qualified subsets of participants can recover the secret image by superimposing their transparencies, but non-qualified subsets of participants have no information about the secret image. Pixel expansion, which represents the number of subpixels in the encoding of the secret image, should be as small as possible. Optimal schemes are those that have the minimum pixel expansion. In this paper we study the pixel expansion of hypergraph access structures and introduce a number of upper bounds on the pixel expansion of special kinds of access structures. Also we demonstrate the minimum pixel expansion of induced matching hypergraph is sharp when every qualified subset is exactly one edge with odd size. Furthermore we explain that the minimum pixel expansion of every graph access structure $P_{n}$ is exactly $lceil frac{ n+1}{2}rceil$. It indicates the lower bound mentioned in [4] is sharp.
ACECR at Tarbiat Modares University
Iranian Journal of Mathematical Sciences and Informatics
1735-4463
5
2
2010
11
1
Energy of Graphs, Matroids and Fibonacci Numbers
55
60
EN
Saeid
Alikhani
Mohammad A.
Iranmanesh
The energy E(G) of a graph G is the sum of the absolute values of the eigenvalues of G. In this article we consider the problem whether generalized Fibonacci constants $varphi_n$ $(ngeq 2)$ can be the energy of graphs. We show that $varphi_n$ cannot be the energy of graphs. Also we prove that all natural powers of $varphi_{2n}$ cannot be the energy of a matroid.
ACECR at Tarbiat Modares University
Iranian Journal of Mathematical Sciences and Informatics
1735-4463
5
2
2010
11
1
Notes on some Distance-Based Invariants for 2-Dimensional Square and Comb Lattices
61
68
EN
Tomislav
Doslic
Ante
Graovac
Franco
Cataldo
Ottorino
Ori
We present explicit formulae for the eccentric connectivity index and Wiener index of 2-dimensional square and comb lattices with open ends. The formulae for these indices of 2-dimensional square lattices with ends closed at themselves are also derived. The index for closed ends case divided by the same index for open ends case in the limit N →;infin defines a novel quantity we call compression factor. This factor was calculated for both eccentric connectivity and Wiener index for 2- dimensional square lattice.