A subset S of nodes in a graph G is k-connected m-dominating set ((k , m)-cds) if the subgraph G[S] induced by and every $$v \in V {\setminus } S$$ has at least m neighbors S. In k -Connected -Dominating Set m)-CDS) problem, goal to find minimum weight (k, m)-cds node-weighted graph. For $$m \ge k$$ we obtain following approximation ratios. unit disk graphs improve ratio $$O(k \ln k)$$ Nutov (I...

The new type of paranormal operators that have been defined in this study on the Hilbert space, is operators. In paper we introduce and discuss some properties concept such as: sum product two paranormal, power paranormal. Further, relationships between other kinds studied.

conclusions the results indicate that the rates of esbls are high in urine e. coli and k. pneumoniae isolates from tehran hospitals. also this study indicates that the urine isolates from male patients are significantly more resistant than the female isolates. materials and methods a total of 190 e. coli and k. pneumoniae isolates were collected from patients’ urine samples in hospitals from te...

ABSTRACT. Suppose G is a graph, A(G) its adjacency matrix and f(G, x)=x^n+a_(n-1)x^(n-1)+... is the characteristic polynomial of G. The matching polynomial of G is defined as M(G, x) = x^n-m(G,1)x^(n-2) + ... where m(G,k) is the number of k-matchings in G. In this paper, we determine the relationship between 2k-th coefficient of characteristic polynomial, a_(2k), and k-th coefficient of matchin...