Describes a string-searching algorithm for multiple patterns in a text string; explains the construction of a pattern-matching machine; presents a theoretical analysis and empirical evidence that supports the sublinearity of the algorithm; and compares this algorithm with the Boyer-Moore algorithm for a single pattern. (Contains 10 references.)…

Using examples of data from the areas of information retrieval and of multivariate data analysis, six hierarchic clustering algorithms (single link, median, centroid, group average, complete link, Wards's) are examined and evaluated by using three proposed coefficients of hierarchic structure. Nine references are cited. (EJS)

Discusses the problem of processing fuzzy queries in databases and information retrieval systems and presents a prototype of a fuzzy query processing system for databases that is based on data clustering and uses Pascal programing language. Clustering schemes are explained, and the system architecture that uses natural language is described. (14…

Explains, with supporting figures and flowcharts of programing logic, two search strategies introduced to the MORPHS System since 1976: one that employs the normal Boolean operators in strings without bracketing or in the form of marked steps, and one that treats a string of keywords as a compound word. (Author/JD)

This issue contains nine articles that provide an overview of trends and research in parallel information retrieval. Topics discussed include network design for text searching; the Connection Machine System; PThomas, an adaptive information retrieval system on the Connection Machine; algorithms for document clustering; and system architecture for…

Considers problem of optimal scheduling of Boolean expression (each Boolean variable represents binary outcome of program module) on single-processor system. Optimization discussed consists of finding operand arrangement that minimizes average execution costs representing consumption of resources (elapsed time, main memory, number of…

Describes a prototype system for interactive knowledge-based indexing of the medical literature. Topics covered include current indexing practice; knowledge-based systems using frames; various types of assistance provided by the prototype system; and current research activities and plans for the development of the system. (17 references) (CLB)

Following a discussion of derivative versus assignment indexing, use of roles, and concept behind Preserved Concept Indexing System, features of PERMDEX (microcomputer program to assist in creation of permuted printed index) are described including indexer input and prompts, the shunting algorithm, and sorting and printing routines. Fourteen…

Presents uniform and efficient approach for processing all truncated query terms in information retrieval which requires one disk access to obtain from the permuted dictionary all strings represented by truncated term. The problem of the overhead storage required to implement the permuted dictionary is discussed. Fifteen references are provided.…

Presents an algorithm for use in online information retrieval which will generate a list of bibliographic citations derived from a preselected relevant document and which measures the relatedness of retrieved items to the preselected document. A test of the algorithm in retrieving medical literature is described. Two figures are included. (JL)

Discussion of a new method of index term dictionary compression in an inverted-file-oriented database highlights a technique of word coding, which generates short fixed-length codes obtained from the index terms themselves by analysis of monogram and bigram statistical distributions. Substantial savings in communication channel utilization are…

Zipfian laws for frequency distributions of word pairs and longer phrases are derived from text sample analysis. From crossing of Zipfian curves, it is deduced that number of multi-word phrases that occur frequently in text is surprisingly small, of same order of magnitude as number of individual word-types. (8 references) (EJS)

Study results indicate that it is feasible to develop automatic name recognition algorithms to distinguish character strings representing names from other character strings occurring in English language titles. This finding offers cautious promise for alleviating some of the labor intensive work of cataloging. (16 references) (Author/SD)