Showing papers by "Paul Morris published in 1993"
Proceedings Article•
11 Jul 1993TL;DR: This paper describes an iterative improvement algorithm, called Breakout, that can escape from local minima, and proves that an idealized (but less efficient) version of the algorithm is complete.
Abstract: A number of algorithms have recently been proposed that use iterative improvement (a form of hill-climbing) to solve constraint satisfaction problems. These techniques have had dramatic success on certain problems. However, one factor limiting their wider application is the possibility of getting stuck at non-solution local minima. In this paper we describe an iterative improvement algorithm, called Breakout, that can escape from local minima. We present empirical evidence that this method is very effective in cases where previous approaches have difficulty. Although Breakout is not theoretically complete, in practice it appears to almost always find solutions, for solvable problems. We prove that an idealized (but less efficient) version of the algorithm is complete.
384 citations
TL;DR: This paper provides a precise formalization of the consequences entailed by a defeasible knowledge base, develops the computational machinery necessary for deriving these consequences, and compares the behavior of the maximum entropy approach to those of Ɛ-semantics and rational closure.
Abstract: An approach to nonmonotonic reasoning that combines the principle of infinitesimal probabilities with that of maximum entropy, thus extending the inferential power of the probabilistic interpretation of defaults, is proposed. A precise formalization of the consequences entailed by a conditional knowledge base is provided, the computational machinery necessary for drawing these consequences is developed, and the behavior of the maximum entropy approach is compared to related work in default reasoning. The resulting formalism offers a compromise between two extremes: the cautious approach based on the conditional interpretations of defaults and the bold approach based on minimizing abnormalities. >
178 citations
TL;DR: Following the time-course of changes in concentrations of glyceollin and abscisic acid in inoculated metalaxyl-treated and untreated plants provides additional evidence that the resistance phenotype induced byMetalaxyl treatment duplicates in detail the resistance response that follows recognition of an incompatible race of P. sojae.
10 citations
TL;DR: It was concluded that smoking did have bidirectional effects as a function of task demand, but there was no evidence that these physiological changes were functional and the smoking behavior data gave no indication as to the cause of these changes.
7 citations