## Search

Now showing items 1-10 of 209

#### Maximum Stable Set Formulations and Heuristics Based on Continuous Optimization

(2000-12)

The stability number for a given graph G is the size of a maximum stable set in G. The Lovasz theta number provides an upper bound on the stability number and can be computed as the optimal value of the Lovasz semidefinite ...

#### The Steepest Descent Minimization of Double-Well Stored Energies Does Not Yield Vectorial Microstructures

(2001-03)

We prove that the Steepest Descent algorithm applied to the minimization of total stored energies with rank-one related rotationally symmetric energy wells does not produce relaxing vectorial microstructures with non-trivial ...

#### Rank-Two Relaxation Heuristics for Max-Cut and Other Binary Quadratic Programs

(2000-11)

Semidefinite relaxation for certain discrete optimization problems involves replacing a vector-valued variable by a matrix-valued one, producing a convex program while increasing the number of variables by an order of ...

#### Imaging Complex Structures With Semi-recursive Kirchhoff Migration

(2000-05)

Attempting to image the subsurface in areas of complex geology and rapid lateral velocity variation is a challenging problem. In particular, using prestack Kirchhoff migration in conjunction with first arrival travel times ...

#### On Eliminating Square Paths in a Square Lattice

(2000-04)

Removing the minimum number of vertices or points from a square lattice such that no square path exists is known as the square path problem. Finding this number as the size of the lattice increases is not so trivial. Results ...

#### Simultaneous Structure Factor and Contrast Transfer Function Parameter Determination in Transmission Electron Microscopy

(2000-08)

We present a new method that allows a fully automated simultaneous determination of the structure factor and the parameters of the Contrast Transfer Function (CTF) and noise function. No previous knowledge of the structure ...

#### On Characterizing Graphs with Branchwidth at Most Four

(2001-04)

There are several ways in which we can characterize classes of graphs. One such way of classifying graphs is by their brachwidth. In working to characterize the class of graphs with brachwidth at most four beta4 we have ...

#### Restricted 2-factors in Bipartite Graphs

(2000-10)

The k-restricted 2-factor problem is that of finding a spanning subgraph consisting of disjoint cycles with no cycle of length less than or equal to k. It is a generalization of the well known Hamilton cycle problem and ...

#### An Efficient Algorithm for Calculating the Heat Capacity of a Large-scale Molecular System

(2001-02)

We present an efficient algorithm for computing the heat capacity of a large-scale molecular system. The new algorithm is based on a special Gaussian quadrature whose abscissas and weights are obtained by a simple Lanczos ...

#### Surrogate Modelling and Space Mapping for Engineering Optimization: A Summary of the Danish Technical University November 2000 Workshop

(2000-12)

This is intended to be an outline of the topics presented in the November 16-18, 2000 workshop held at the Danish Technical University in Lyngby outside Copenhagen. The focus of this workshop was on the construction of ...