Robertson and Seymour prove that a set of graphs of bounded tree-width is wellquasi-ordered by the graph minor relation. By extending their methods to matroids, Geelen, Gerards, and Whittle prove that a set of matroids representable over a fixed finite field are well-quasi-ordered if it has bounded branch-width. More recently, it is shown that a set of graphs of bounded rank-width (or clique-wi...

This paper is intended as a first step in a program for a full algorithmic enumeration of lattice 3-polytopes. The program is based in the following two facts, that we prove: • For each n there is only a finite number of (equivalence classes of) 3polytopes of lattice width larger than one, where n is the number of lattice points. Polytopes of width one are infinitely many, but easy to classify....

A great number of wheel tests are required in designing and manufacturing of wheels to meet satisfactory requirements. The impact performance of a wheel is the major concern. Numerical implementation of impact test is essential to shorten the design time, improve the mechanical performance and lower development cost. Project includes the “Topology Optimization of Cast Aluminium Alloy wheel” usi...

in this paper, the temperature distribution around a moving heat source had been investigated including the phase change and non phase change . in non-phase change state, the governing equation was converted to finite difference equation by finite volume method and the equation was solved by alternating direction implicit method. this method was unconditionally stable . in phase change state, t...

three dimensioned finite element analysis were conducted on concrete block paving. in order to verify the calculated results, an experimental case study was analyzed. good agreement was observed between the measured and the calculated results. based on the finite element analysis results and available failure models, comprehensive design charts were developed for port and industrial pavement wh...

For a finite poset P let EXT(P ) denote the following decision problem. Given a finite poset Q and a partial map f from Q to P , decide whether f extends to a monotone total map from Q to P . It is easy to see that EXT(P ) is in the complexity class NP. In [SIAM J. Comput., 28 (1998), pp. 57–104], Feder and Vardi define the classes of width 1 and of bounded strict width constraint satisfaction ...

Let A be finite relational structure of finite type, and let CSP (A) denote the following decision problem: if I is a given structure of the same type as A, is there a homomorphism from I to A ? To each relational structure A is associated naturally an algebra A whose structure determines the complexity of the associated decision problem. We investigate those finite algebras arising from CSP’s ...

Path-width of matroids naturally generalizes better known path-width of graphs, and is NP-hard by a reduction from the graph case. While the term matroid path-width was formally introduced by Geelen–Gerards–Whittle [JCTB 2006] in pure matroid theory, it was soon recognized by Kashyap [SIDMA 2008] that it is the same concept as long-studied so called trellis complexity in coding theory, later na...

Let p be a prime. It is proved that a non-trivial word w from a free group F has finite width in every finitely generated pro-p group if and only if w 6∈ (F ′)pF ′′. Also it is shown that any word w has finite width in a compact p-adic group.