A defensive k-alliance in a graph G = (V, E) is a set of vertices A ⊆ V such that for every vertex v ∈ A, the number of neighbors v has in A is at least k more than the number of neighbors it has in V − A (k is a measure of the strength of alliance). In this paper, we deal with two types of sets associated with defensive k-alliances; maximum defensive k-alliance free and minimum defensive k-all...

A nonempty set S ⊂ V is a defensive k-alliance in G = (V,E), k ∈ [−Δ,Δ] ∪ Z, if for every v ∈ S, dS(v) ≥ dS̄(v) + k. A defensive k-alliance S is called exact, if S is defensive k-alliance but is no defensive (k+1)-alliance in G. In this paper we study the mathematical properties of exact defensive k-alliances in graphs. In particular, we obtain several bounds for defensive k-alliance of a graph....

.....................................................................................xii CHAPTER ONE: INTRODUCTION....................................................... 1 The Problem in Perspective.............................................................3 Corrective Feedback............................................................4 Barriers to accepting corrective feedback received........

This study investigated differences between Mexican- and Anglo-American college students on the Psychological Screening Inventory (PSI; Lanyon, 1970, 1973)-a brief personality instrument designed to detect persons who might benefit from more extensive evaluations in mental health settings. Further, this study controlled for the Mexican Americans' acculturation level, age, and socioeconomic stat...

A nonempty set S ⊆ V is a defensive k-alliance in Γ = (V,E), k ∈ [−Δ,Δ] ∩ Z, if for every v ∈ S, δS(v) ≥ δS̄(v) + k. An defensive kalliance S is called critical if no proper subset of S is an defensive k-alliances in Γ = (V,E). The upper defensive k-alliance number of Γ, denoted by Ak(Γ), is defined as the maximum cardinality of a critical defensive k-alliance in Γ. In this paper we study the ma...

A defensive (offensive) k-alliance in Γ = (V,E) is a set S ⊆ V such that for every v ∈ S (v ∈ ∂S), the number of neighbors v has in S is at least k more than the number of neighbors it has in V \ S. A set X ⊆ V is defensive (offensive) k-alliance free, if for all defensive (offensive) k-alliance S, S \ X 6= ∅, i.e., X do not contain any defensive (offensive) k-alliance as a subset. A set Y ⊆ V ...