Discussion of graph-drawing algorithms compares and evaluates five algorithms for generated automatic graphic display of sentence dependency structures that have been implemented in the TEXTNET text structure management system. Evaluation criteria are discussed, and a test of the algorithms with a database of newspaper articles is described. (16…

Describes the PADOK-II project in Germany, which was designed to give information on the effects of linguistic algorithms on retrieval in a full-text database, the German Patent Information System (GPI). Relevance assessments are discussed, statistical evaluations are described, and searches are compared for the full-text section versus the…

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…

Discusses genetic algorithms in information retrieval, especially for relevance feedback, and evaluates the efficacy of a genetic algorithm with various order-based fitness functions for relevance feedback in a test database. Compares results with the Ide dec-hi method, one of the best traditional methods. (Contains 56 references.) (Author/LRW)

Compares the performance of inverted and signature file organizations in handling incrementally specified Boolean queries to an information retrieval system. The discussion covers the impact of more sophisticated signature file organizations, related problems, and possible future work. (65 references) (CLB)

Discusses end-user searching in Boolean information retrieval systems considers the role of search intermediaries and proposes a model of user preferences that incorporates a user's profile. Highlights include document representation; information queries; document output ranking; calculating user profiles; and selecting documents for a local…

Presents an improved inverted region quadtree variation called Dynamic Inverted Quadtree that is able to support and index a pictorial database. Pattern-searching algorithms are described, and the space needs of Fully Inverted and Dynamic Inverted Quadtrees are analytically compared based on a model of image randomness expressed as a branching…

This study of ranking algorithms used in a Boolean environment is based on an evaluation of factors affecting document ranking by information retrieval systems. The algorithms were decomposed into term weighting schemes and similarity measures, representatively selected from those known to exist in information retrieval environments, before being…

Investigates the value of applying principles derived from simulated annealing to clustering tuples in database design, and compares this technique with a graph-collapsing clustering method. It is concluded that, while the new method does give superior results, the expense involved in algorithm run time is prohibitive. (24 references) (CLB)

Describes a project at the University of Sheffield that is investigating the use of nearest-neighbor retrieval algorithms for full-text searching. Nearest-neighbor searching is compared with Boolean retrieval and hypertext, and an experimental text retrieval system called INSTRUCT (Interactive System for Teaching Retrieval Using Computational…

Presents a probabilistic technique to retrieve passages from texts having a large size or heterogeneous semantic content. Results of experiments comparing the probabilistic technique to one based on a text segmentation algorithm revealed that the passage size affects passage retrieval performance; text organization and query generality may have an…

Analyzes the properties of genetic sequences that cause the failure of classical algorithms used for data compression. A lossless algorithm, which compresses the information contained in DNA and RNA sequences by detecting regularities such as palindromes, is presented. This algorithm combines substitutional and statistical methods and appears to…

Discusses the results of modeling the performance of searching large text databases via various parallel hardware architectures and search algorithms. The performance under load and the cost of each configuration are compared, and a common search workload used in the modeling is described. (Contains 26 references.) (LRW)

Reports on the use of stemming for Slovene language documents and queries in free-text retrieval systems and demonstrates that an appropriate stemming algorithm results in an increase in retrieval effectiveness when compared with nonstemming processing. A comparison is made with stemming of English versions of the same documents and queries. (24…

Discussion of relevancy in information retrieval systems focuses on an analysis of the efficiency of various cluster-based retrieval (CBR) strategies. A method for combining CBR and inverted index search is proposed that is cost effective in terms of time efficiency; and results of experiments are reported. (Contains 32 references.) (LRW)