There have been interesting recent developments in methods for solving optimization problems without making use of derivative (sensitivity) information. While calculus based methods that employ derivative information can be extremely eecient and very eeec-tive, they are not applicable to all MDO problems, for instance, when the function to be optimized is nondiierentiable, when sensitivity info...

In recent years Rayleigh waves have been used increasingly as a nondestructive tool to obtain near-surface S-wave velocity, one of the key parameters in environmental and engineering applications (Miller et al., 1999a, 1999b; Park et al., 1998, 1999; Xia et al., 1999, 2003; Foti et al., 2002; Beaty and Schmitt, 2003; Tian et al., 2003; Zhang and Chan, 2003; Lin and Chang, 2004; O’Neill et al., ...

We present a new method to compute depth-three threshold circuits for pattern classi cation problems. The rst layer of the circuits is calculated from a sample set S of the classi cation problem by a local search strategy that minimises the error on S for each individual gate. The local search is based on simulated annealing with the logarithmic cooling schedule c(k) = = ln (k + 2). The paramet...

A pattern database abstraction (PDB) is a heuristic function in a form of a lookup table. A PDB stores the cost of optimal solutions for instances of abstract problems (subproblems). These costs are used as admissible heuristics for the original problem. Perimeter search (PS) is a form of bidirectional search. First, a breadth-first search is performed backwards from the goal state. Then, a for...

Abstract: Previous analyses of pattern search algorithms for unconstrained and linearly constrained minimization have focused on proving convergence of a subsequence of iterates to a limit point satisfying either directional or first-order necessary conditions for optimality, depending on the smoothness of the objective function in a neighborhood of the limit point. Even though pattern search m...

Pattern databases are dictionaries for heuristic estimates storing state-to-goal distances in state space abstractions. Their effectiveness is sensitive to the selection of the underlying patterns. Especially for multiple and additive pattern databases, the manual selection of patterns that leads to good exploration results is involved. For automating the selection process, greedy bin-packing h...

Previous analyses of pattern search algorithms for unconstrained and linearly constrained minimization have focused on proving convergence of a subsequence of iterates to a limit point satisfying either directional or first-order necessary conditions for optimality, depending on the smoothness of the objective function in a neighborhood of the limit point. Even though pattern search methods req...

We introduce a new asynchronous parallel pattern search (APPS). Parallel pattern search can be quite useful for engineering optimization problems characterized by a small number of variables (say, fifty or less) and by objective functions that are expensive to evaluate, such as those defined by complex simulations that can take anywhere from a few seconds to many hours to run. The target platfo...

This paper addresses the search problem for lost floating targets on sea surface. Given the expected search region, we analyze spiral search patterns for finding the target. Specifically, we consider two search patterns: outward spiral and inward spiral. The outward spiral pattern is a greedy strategy which initializes from the mean of the search region and expands outwards to cover the entire ...

Ramasubramanian, V. and K.K. Paliwal, An efficient approximation-elimination algorithm for fast nearest-neighbour search based on a spherical distance coordinate formulation, Pattern Recognition Letters 13 (1992) 471-480. An efficient approximation-elimination search algorithm for fast nearest-neighbour search is proposed based on a spherical distance coordinate formuTation, where a vector in K...