Analyzes the amount of compression possible when arithmetic coding is used for text compression in conjunction with various input models. Algorithms are analyzed; modeling effects are considered; scaling is discussed; higher order models are examined, including prediction by partial matching; and coding effects are described. (34 references) (LRW)

Looks for a method to formulate algorithms useful for the synthesis of Czech in machine translation where the point of departure for the synthesis can be more or less identical with the semantic representation. (Author/PF)

Presents a model of information retrieval based on plausible inference which suggests that techniques should be found for combining multiple search strategies into an overall assessment of a document's relevance. The results of experiments designed to test this approach using a simple spreading activation search are discussed. (21 references) (CLB)

Describes the development of a structural model of document retrieval based on lexical-semantic relationships between index terms. An algorithm that uses tree-to-tree distance to measure structural closeness between a document and a query statement is explained, and the proposed model is compared to a vector retrieval model. (18 references) (LRW)

Describes a computerized information retrieval system that uses three agglomerative hierarchic clustering algorithms--single link, complete link, and group average link--and explains their implementations. It is noted that these implementations have been used to cluster a collection of 12,000 documents. (LRW)

Views information as residual or catalytic form of energy which regulates other forms of energy in natural and artificial systems. Parallel human information processing (production systems, algorithms, heuristics) and information measurement are discussed. Suggestions for future research in area of parallel information processing include a matrix…

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)

Introduces two distribution schemes that partition documents over multiple processors and the corresponding multiprocessor retrieval algorithms that match relevant documents to user queries. The suggested framework is based on a general purpose hypercube multicomputer architecture with a dedicated disk for each node. A timing analysis for the…

Reports on the validity of the Multiple Poisson (nP) model of word distribution in full-text document collections. A practical algorithm for determining whether a certain word is distributed according to an nP distribution and the results of a test of this algorithm in three different document collections are described. (14 references) (KRN)

Describes the theoretical framework of a retrieval system that uses data structures called bitmaps to improve search algorithms for medium-sized systems. Information retrieval systems that contain the full text of the documents are discussed, and the use of inverted files such as concordances for small texts is explained. (24 references) (LRW)

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…

Describes fast, dynamic update algorithms for document retrieval systems. B-trees are discussed; the M-B-T file directory structure is explained; insertions and deletions in inverted files are described; and performance evaluation is discussed. An appendix provides the formal definition of an M-B-T directory. (Contains 18 references.) (LRW)

Presents a mathematical theory that can be used to define concentration places of objects within unordered classes. The application to research on the evolution of journals and subject areas is illustrated, and an online method of calculating concentration evolution is described. (1 references) (CLB)

Presents a modification function for weights of descriptors for documents in fuzzy retrieval systems which includes some desirable properties that are lacking in the model proposed by Choros and Danilowicz in their study on relative indexing. (MBR)

Discusses properties of multiple attribute tree (MAT) and inverted file structures; establishes suitability of MAT data structure for bibliographic files using worst-case performance measures; provides arguments to establish MAT average case superiority; and proposes an efficient adaptation of MAT data structure to exploit special features of MAT…