Here we describe an approach, based upon a notion of problem similarity, that can be used when attempting to devise a heuristic for a given search problem (of a sort represented by graphs). The proposed approach relies on a change in perspective: instead of seeking a heuristic directly for a given problem PI, one seeks instead a rolp___21gm P2 easier to solve than PI and related to PI in a cert...

A problem with A* is that it fails to guarantee opt imal solutions when its heuristic, h, overestimates. Since optimal solutions are often desired and an underestimating h is not always available, we seek to remedy this. From a nonadmissible h an admissible one is generated using h's statistical properties. The new heuristic, hm, is obtained by inverting h wi th respect to its own least upper b...

In rea l -wor ld domains a concept to be learned may be unwieldy and the environment may be less than ideal. One combinat ion of difficulties occurs if the concept is probabi l ist ic and the learning si tuat ion is dynamic. In this case, the data may be noisy and biased. These difficulties arise when learning evaluation functions, which can be considered as concepts. A representative problem, ...

Au nanoparticles with small sizes (2-3 nm) were effectively stabilized in the mesopores of (S)-(-)-2-pyrrolidinone-5-carboxylic acid-modified SBA-15, which showed superior catalytic properties in aerobic oxidation of alcohols, compared with pyrrolidone-free SBA-15 supported Au catalysts.

The polymeric title compound, [Ce(C(7)H(3)N(2)O(6))(3)(C(2)H(6)OS)(2)](n), exists as a linear chain along [111] as the three dinitro-benzoate anions each engages in bridging adjacent dimethyl sulfoxide (DMSO) coordinated Ce(III) atoms. The metal atoms are surrounded by eight O atoms in a square-anti-prismatic environment. There are two independent formula units in the asymmetric unit. The S ato...

The conformation of the C=O bond in the title compound 2MP4MBA, C(15)H(14)O(2), is anti to the ortho-methyl group in the phen-oxy ring. The bond parameters in 2MP4MBA are similar to those in 3-methyl-phenyl 4-methyl-benzoate (3MP4MBA), 4-methyl-phenyl 4-methyl-benzoate (4MP4MBA) and other aryl benzoates. The dihedral angle between the two aromatic rings in 2MP4MBA is 73.04 (8)°.

We report in this work the preparation and antibacterial evaluation of a series of N-monoacylated diamines against six Gram-positive and 11 Gram-negative bacteria. The results obtained showed the existence of relationship between lipophilicity and antibacterial activity of the tested compounds. The best results were obtained against Gram-positive bacteria for compounds having a 10-12 carbons al...

In situations where one needs to make a sequence of decisions, it is often believed that looking ahead will help produce better decisions. However, it was shown 30 years ago that there are “pathological” situations in which looking ahead is counterproductive. Two long-standing open questions are (a) what combinations of factors have the biggest influence on whether lookahead pathology occurs, a...

SiO(2) mesoporous molecular sieve SBA-15 with the incorporation of erbium ions is studied as a novel type of nanoscopic composite photoluminescent material in this paper. To enhance the photoluminescence efficiency, two schemes have been used for the incorporation of Er(3+) where (1) Er(3+) is ligated with bis-(perfluoromethylsulfonyl)-aminate (PMS) forming Er(PMS)(x)-SBA-15 and (2) Yb(3+) is c...