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 ...

Foam core sandwich composites are finding a wider breadth of use in aerospace, automotive, and construction applications. These structures present unique challenges in terms of material failure and interaction and are highly sensitive to damage and imperfections introduced during manufacturing. An emerging class of 3D Fiber Reinforced Foam Core (3DFRFC) aims to replace monolithic foams used in ...

Abstract A numerical analysis of the effect temperature on dynamics sandwich beam model with a viscoelastic core is presented. The under was described standard rheological model. This solution allows one to study material strength properties. Calculations were performed Finite Element Method in ANSYS software. results calculations showed significant influence properties test. confirmed damping ...

Sandwich plates with two thin stiff face-sheets and a soft center core have been used in many constructions for which the dominating load is transverse bending. Many theoretical/numerical analyses devoted to studying deformation mechanism of such structure. But relatively limited experimental investigations are present this field they often self-content little connection existing theoretical pu...