Deciding whether a collection of unrooted trees is compatible is a fundamental problem in phylogenetics. Two different graph-theoretic characterizations of tree compatibility have recently been proposed. In one of these, tree compatibility is characterized in terms of the existence of a specific kind of triangulation in a structure known as the display graph. An alternative characterization exp...

The P4-sparse Graph Sandwich Problem asks, given two graphs G 1 = (V, E1) and G2 = (V, E2), whether there exists a graph G = (V, E) such that E1 ⊆ E ⊆ E2 and G is P4-sparse. In this paper we present a polynomial-time algorithm for solving the Graph Sandwich Problem for P4-sparse graphs. c © 2008 Elsevier B.V. All rights reserved.

In this paper we introduce the simultaneous membership problem, defined for any graph class C characterized in terms of representations, e.g. any class of intersection graphs. Two graphs G1 and G2, sharing some vertices X (and the corresponding induced edges), are said to be simultaneous members of graph class C, if there exist representations R1 and R2 of G1 and G2 that are “consistent” on X ....

A graph is a 1-join composition if its vertex set can be partitioned into four nonempty sets AL; AR ; SL and SR such that: every vertex of AL is adjacent to every vertex of AR; no vertex of SL is adjacent to vertex of AR∪SR; no vertex of SR is adjacent to a vertex of AL∪SL. The graph sandwich problem for 1-join composition is de9ned as follows: Given a vertex set V , a forced edge set E, and a ...

It is well known that in misspecified parametric models, the maximum likelihood estimator (MLE) is consistent for the pseudo-true value and has an asymptotically normal sampling distribution with "sandwich" covariance matrix. Also, posteriors are asymptotically centered at the MLE, normal and of asymptotic variance that is in general different than the sandwich matrix. It is shown that due to t...

The task of accurately classifying marine fish species is great importance to ecosystem investigations, but previously used methods were extremely labor-intensive. Computer vision approaches have the advantages being long-term, non-destructive, non-contact and low-cost, making them ideal for this task. Due unique nature environment, data difficult collect often poor quality, learning how identi...

The main purpose of the present paper is to investigate some subordination-preserving and superordination-preserving properties of a certain family of integral operators. Several sandwich-type results associated with this family of integral operators are also derived. 2000 Mathematics Subject Classification. Primary 30C45; Secondary 30C80.

The purpose of the present paper is to obtain subordinationand superordinationpreserving properties for a class of integral operators defined on the space of normalized analytic functions in the open unit disk. We also consider the sandwich-type theorems for these integral operators. 2000 Mathematics Subject Classification. Primary 30C80; Secondary 30C25, 30C45.

In the present paper, we obtain sandwich results involving Hadamard product for certain normalized analytic functions associated with Dziok-Srivastava operator in the open unit disk. Our results extend corresponding previously known results. 2000 Mathematics Subject Classification: Primary 30C45; Secondary 30C80.

Using the methods of differential subordination and superordination, sufficient conditions are determined on the Liu-Srivastava linear operator of meromorphic functions in the punctured unit disk to obtain respectively the best dominant and the best subordinant. New sandwich-type results are also obtained. 2000 Mathematics Subject Classification: Primary 30C80; Secondary 30C45