In this paper we consider contact metric R-harmonic manifolds M with ξ belonging to (κ, μ)-nullity distribution. In this context we have κ ≤ 1. If κ < 1, then M is either locally isometric to the product E × S(4), or locally isometric to E(2) (the group of the rigid motions of the Euclidean 2-space). If κ = 1, then M is an Einstein-Sasakian manifold. Mathematics Subject Classification: 53C05, 5...

In the present paper, we proposed a new efficient rank updating methodology for evaluating the rank (or equivalently the nullity) of a sequence of block diagonal Toeplitz matrices. The results are applied to a variation of the partial realization problem. Characteristically, this sequence of block matrices is a basis for the computation of the Weierstrass canonical form of a matrix pencil that ...

The Colin de Verdière parameters, μ and ν, are defined to be the maximum nullity of certain real symmetric matrices associated with a given graph. In this work, both of these parameters are calculated for all chordal graphs. For ν the calculation is based solely on maximal cliques, while for μ the calculation depends on split subgraphs. For the case of μ our work extends some recent work on com...

unequal bargaining power of parties to a franchise contract and their unequal access to information that may be effective in determining the consideration of a contract; has caused different legal systems impose obligations to franchisor to poise the contractual balancing. commitment to expose accurate and comprehensive pre-contractual information about all aspects related to franchise is the m...

The problem of finding contained rewritings of queries using views is of great importance in mediated data integration systems. In this paper, we first present a general approach for finding contained rewritings of unions of conjunctive queries with arbitrary built-in predicates. Our approach is based on an improved method for testing conjunctive query containment in this context. Although conc...

Explicit expressions of UMVUE for variance components are obtained for a class of models that include balanced cross nested random models. These estimators are used to derive tests for the nullity of variance components. Besides the usual F tests, generalized F tests will be introduced. The separation between both types of tests will be based on a general theorem that holds even for mixed model...

We study almost Kähler manifolds whose curvature tensor satisfies the second curvature condition of Gray (shortly AK 2). This condition is interpreted in terms of the first canonical Hermitian connection. It turns out that this condition forces the torsion of this connection to be parallel in directions orthogonal to the Kähler nullity of the almost complex structure. We prove a local structure...