The reconstruction of evolutionary trees is a major problem in biology, and many evolutionary trees are estimated using heuristics for the NP-hard optimization problem Maximum Parsimony. The current heuristics for searching through tree space use a particular technique, called “tree-bisection and reconnection”, or TBR, to transform one tree into another tree; other less-frequently used transfor...

This paper introduces a new and very simple search methodology called Late Acceptance Hill-Climbing (LAHC). It is a one-point iterative search algorithm, which accepts non-improving moves when a candidate cost function is better (or equal) than it was a number of iterations before. This value appears as a single algorithmic input parameter which determines the total processing time of the searc...

Block and stream ciphers are made from Boolean functions that usually require a compromise between several conflicting cryptographic criteria. Although some constructions exist to generate Boolean functions satisfying one or more criteria, such as balance and high nonlinearity, there are often drawbacks to them such as low nonlinear order. In this paper we present a new algorithm for simple mod...

Many learning systems search through a space of possible performance elements, seeking an element whose expected utility, over the distribution of problems, is high. As the task of nding the globally optimal element is often intractable, many practical learning systems instead hill-climb to a local optimum. Unfortunately, even this is problematic as the learner typically does not know the under...

Résumé en anglais Hill-climbing constitutes one of the simplest way to produce approximate solutions of a combinatorial optimization problem, and is a central component of most advanced metaheuristics. This paper focuses on evaluating climbing techniques in a context where deteriorating moves are not allowed, in order to isolate the intensification aspect of metaheuristics. We aim at providing ...

We hypothesize that evolutionary algorithms can effectively schedule coordinated fleets of Earth observing satellites. The constraints are complex and the bottlenecks are not well understood, a condition where evolutionary algorithms are often effective. This is, in part, because evolutionary algorithms require only that one can represent solutions, modify solutions, and evaluate solution fitne...

A new approach to drug discovery is based on the generation of high diversity libraries of DNA, RNA, peptides or small molecules. Search of such libraries for useful molecules is an optimization problem on high-dimensional molecular fitness landscapes. We utilize a spin-glass-like model, the NK model, to analyze search strategies based on pooling, mutation, recombination and selective hill-clim...

............................................................................................................. iv Introduction ........................................................................................................ 1 Background ........................................................................................................ 6 Proposed Methodology ............................

This paper presents techniques to integrate boundary overlap into concept assignment using Plausible Reasoning. Heuristic search techniques such as Hill climbing and Genetic Algorithms are investigated. A new fitness measure appropriate for overlapping concept assignment is introduced. The new algorithms are compared to randomly generated results and the Genetic Algorithm is shown to be the bes...