Bulletin of the International Mathematical Virtual Institute

123-131

Authors: Vanja Stepanović

Here we treat the problem of representability of an algebraic lat- tice by the weak congruence lattice of an algebra, i.e. the lattice of all sym- metric and transitive relations compatible with algebra. We prove that some suborders of the representable lattices are representable, and give conditions under which these suborders are also sublattices of the initial lattices. We also prove that the direct product of a set of representable lattices, slightly extended, is representable itself.

141-152

Authors: R. A. Rashwan and S. I. Moustafa

In this paper we prove a common xed point theorem for six compatible self mappings of type (A) in a complete non-Archimedean Menger PM-space.

163-166

Authors: Daniel A. Romano

Each quasi-antiorder  on anti-ordered semigroup S induces anti- congruence q on S such that S=q is an ordered semigroup under anti-order induced by . In this note we prove that the converse of this statement also holds: Each anti-congruence q on a semigroup (S;=; ̸=; ·) such that S=q is an anti-ordered semigroup induces a quasi-antiorder on S.

173-184

Authors: D. Lakshmanaraj and V. Swaminathan

Let G = (V;E) be a simple graph. A partition of V (G) into in- dependent,externally equitable sets is called externally equitable proper color partition of G or externally equitable proper coloring of G. The minimum cardinality of an externally equitable proper coloring of G is called exter- nally equitable chromatic number of G and is denoted by ee(G). Since  = ffu1g; fu2g;


; fungg where V (G) = fu1; u2;


; ung is an externally equitable proper coloring of G, externally equitable proper color partition ex- ists in any graph G . In this paper, this new parameter is introduced and studied.

195-204

Authors: A. S. Saluja, R.A.Rashwan and Pankaj Kumar Jhade

The aim of this paper is to study the strong convergence of an implicit iteration process to a common xed point for a nite family of asymp- totically nonexpansive nonself mappings in a uniformly convex Banach spaces.

219-221

Authors: József Sándor

We offer a new proof of a logarithmic inequality used in the theory of quasiconformal mappings and norm inequalities for vector functions [1].

235-237

Authors: Ramiz Vugdalić and Fatih Destović

We analyse continuously differentiable functions f : Rr{0} → R, that are the solutions of functional equation f(st) = f(s) + f(t): We prove that f ≡ 0; and logarithmic functions f(t) = loga |t|, (0 < a ̸= 1) are the only solutions of the equation above.

1-7

Authors: I. H. Nagaraja Rao, G. Venkata Rao and S. Rajesh

The aim of this paper is to show that the comment of Rashwan and Maustafa [5] on a result of Sharma and Deshpande [8] is not true by pointing out the inconsistency in their claimed example. Further the results of the former authors are generalised and are supported by examples.

17-27

Authors: Aysun Ayatac and Tufan Turaci

In communication networks, "vulnerability" indicates the resistance of a network to disruptions in communication after a breakdown of some pro- cessors or communication links. We may use graphs to model networks, as graph theoretical parameters can be used to describe the stability and reliability of communication networks If we think of a graph as model- ing a network, the average lower independence number of a graph is one measure of graph vulnerability. For a vertex v of a graph G = (V;E), the lower independence number iv(G) of G relative to v is the minimum cardinality of a maximal independent set of G that contains v. The av- erage lower independence number of G, denoted by iav(G), is the value iav(G) = 1 jV (G)j P v²V (G) iv(G). In this paper, we de¯ned and examined this parameter and considered the average lower independence number of special graphs and theirs total graphs.

43-46

Authors: Ivan D. Aranđelović and D. Krtinić

In 1920 H. Steinhaus [Sur les distances des points de mesure posi- tive, Fundamenta Mathematicae 1 (1920) 93-104.] proved the following result: "Let A be a Lebesgue measurable set of positive measure. Then there exist at least two points in A such that the distance between them is a rational number". In this paper we shall prove that there exists a sequence (xn)n>1 of di®erent points in A such that the distance between any two of them is a rational number. Further, we shall extend our result to the case when A is a set with the Baire property (non-necessarily Lebesgue measurable).

59-67

Authors: I. H. Nagaraja Rao, S. Rajesh and G. Venkata Rao

In this paper, we claim that the comment of Sastry et.al[2] on a result of Servet Kutukcu and Sushil Sharma[5] is not true by pointing out their non observation of a condition in the hypothesis of the result. Further, the results of [5] are generalized and supported by examples.

77-86

Authors: R. A. Rashwan and S. M. Altwqi

In this paper, we introduce a new one-step iterative scheme to approximate a common ¯xed point of three multivalued nonexpansive map- pings in a uniformly convex real Banach space and establish strong and weak convergence theorems for the proposed process. Our results extend important results.

93-100

Authors: R. Sundareswaran and V. Swaminathan

C.A. Barefoot, et. al. introduced the concept of the integrity of a graph. It is an useful measure of vulnerability and it is de¯ned as follows I(G) = minfjSj +m(G ¡ S) : S ½ V (G)g, where m(G ¡ S) denotes the order of the largest component in G ¡ S. The integrity of the set S is de¯ned as jSj + m(G ¡ S) and is denoted by IS, where m(G ¡ S) denotes the order of maximum component in G¡S. A partition of V (G) into subsets V1; V2; ¢ ¢ ¢ ; Vt such that IVi ; 1 6 i 6 t is a constant is called equi-integrity partition of G. The maximum cardinality of such a partition is called equi-integrity partition number of G and is denoted by EI(G). Since V (G) itself is an equi-integrity partition of G, the existence of EI-partition is guaranteed. In this paper, a study of this new parameter is initiated.

109-116

Authors: Kuppusamy Markandar Dharmalingam

Let G = (V;E) be a simple graph. Let H be the graph constructed from G as follows: V (H) = V (G), two points u and v are adjacent in H if and only if u and v are adjacent and degree equitable in G. H is called the adjacency inherent equitable graph of G or equitable associate of G and is denoted by e(G). This Paper aims at the study of a new concept called equitable associate graph of a graph. In this paper we show that there is relation between e(G) and e¡(G). Further results on the new parameter e(G),e¡(G) and complexity of equitable dominating set are discussed.