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Materials Data on LaPIr by Materials Project

LaIrP is hexagonal omega structure-derived structured and crystallizes in the tetragonal I4_1md space group. The structure is three-dimensional. La is bonded to six equivalent Ir and six equivalent P atoms to form a mixture of edge and face-sharing LaP6Ir6 cuboctahedra. There are two shorter (3.12 Å) and four longer (3.21 Å) La–Ir bond lengths. There are four shorter (3.16 Å) and two longer (3.23 Å) La–P bond lengths. There are two inequivalent Ir sites. In the first Ir site, Ir is bonded in a 9-coordinate geometry to six equivalent La and three equivalent P atoms. All Ir–P bond lengths are 2.40 Å. In the second Ir site, Ir is bonded in a 9-coordinate geometry to six equivalent La and three equivalent P atoms. There are two shorter (3.12 Å) and four longer (3.21 Å) Ir–La bond lengths. All Ir–P bond lengths are 2.40 Å. P is bonded in a 9-coordinate geometry to six equivalent La and three equivalent Ir atoms.

36 MATERIALS SCIENCE↗

An Optical Bit-Counting Algorithm

This paper addresses the omnipresent problem of counting bits - an operation discussed since the very early stages of the establishing of computer science. The need for a quick bit-counting method acquires a special significance with the proliferation of search engines on the Internet. It arises in several other computer applications. This is especially true in information retrieval in which an array of binary vectors is used to represent a characteristic function (CF) of a set of qualified documents. The number of "I"s in the CF equals the cardinality of the set. The process of repeated evaluations of this cardinality is a pivotal point in choosing a rational strategy for deciding whether to constrain or broaden the search criteria to ensure selection of the desired items. Another need for bit-counting occurs when trying to determine the differences between given files, (images or text), in terms of the Hamming distance. An Exclusive OR operation applied to a pair of files results in a binary vector array of mismatches that must be counted.

Mack, Marilyn↗

Approximate Matching as a Key Technique in Organization of Natural and Artificial Intelligence

The basic property of an intelligent system, natural or artificial, is "understanding". We consider the following formalization of the idea of "understanding" among information systems. When system I issues a request to system 2, it expects a certain kind of desirable reaction. If such a reaction occurs, system I assumes that its request was "understood". In application to simple, "push-button" systems the situation is trivial because in a small system the required relationship between input requests and desired outputs could be specified exactly. As systems grow, the situation becomes more complex and matching between requests and actions becomes approximate.

Mack, Marilyn↗