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Showing 1,171 to 1,185 of 2,350 results Save | Export
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Tsotras, Vassilis J.; Kangelaris, Nickolas – Information Systems, 1995
Presents an access method for temporal data called the Snapshot Index that reconstructs a past state of a time-evolving collection of objects. Previous approaches to temporal access methods are reviewed, and migrating data to write-once optical disks are discussed. (Author/LRW)
Descriptors: Access to Information, Databases, Indexes, Mathematical Formulas
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Lee, Heeseok; Park, Taeho – Information Systems, 1995
Discussion of local area networks and multiple file servers for concurrent information retrievals provides a rationale for workload and data allocation and presents an analytical model which will attain effective allocation policies. Nonlinear integer programming is discussed, and computational results show the effectiveness of the heuristic.…
Descriptors: Databases, Heuristics, Information Retrieval, Local Area Networks
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Howard, Paul G.; Vitter, Jeffrey Scott – Information Processing and Management, 1992
Identifies four components of a good predictive lossless image compression method: (1) pixel sequence, (2) image modeling and prediction, (3) error modeling, and (4) error coding. Highlights include Laplace distribution and a comparison of the multilevel progressive method for image coding with the prediction by partial precision matching method.…
Descriptors: Coding, Comparative Analysis, Information Processing, Mathematical Formulas
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Rousseau, Ronald – Information Processing and Management, 1992
This article offers comments and clarifications of Egghe's paper, which dealt with information production processes (IPP) and the Gini index. Topics addressed include the length of the Lorenz curve as a concentration measure, the discrete duality operator, and a Bradford-Leimkuhler distribution. (10 references) (LRW)
Descriptors: Information Science, Mathematical Formulas, Mathematical Models, Measurement Techniques
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Haase, Richard F. – Multivariate Behavioral Research, 1991
Computational formulas are developed for recovering measures of strength of association from approximate "F" tests and chi-square tests associated with four multivariate test statistics. The four statistics include Wilke's Lambda; Pillai's Trace "V"; Hotelling's Trace "T"; and Roy's greatest characteristic root…
Descriptors: Chi Square, Estimation (Mathematics), Mathematical Formulas, Mathematical Models
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Egghe, L. – Information Processing and Management, 1991
Discusses the theory of collaboration and measures of collaboration. Variables for collaborative measures are considered, principles are formulated that good collaborative measures should satisfy, examples and practical calculations are presented, and further problems for research are suggested. (nine references) (LRW)
Descriptors: Computation, Cooperation, Mathematical Formulas, Measurement Techniques
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Rousseau, Ronald; Rousseau, Sandra – Canadian Journal of Information and Library Science, 1993
Reviews informetric, or bibliometric, distributions, including Lotka's, rank frequency distributions, Zipf functions, Mandelbrot functions, Leimkuhler functions, and Bradford's formulations. An example of the use of these techniques to analyze song texts of Thomas Dolby is given, and results are reported that show a fit with a Leimkuhler function.…
Descriptors: Bibliometrics, Mathematical Formulas, Songs, Statistical Distributions
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Bollmann-Sdorra, Peter; Raghavan, Vjay V. – Journal of the American Society for Information Science, 1993
Proposes that document space and query space have different structures in information retrieval and discusses similarity measures, term independence, and linear structure. Examples are given using the retrieval functions of dot-product, the cosine measure, the coefficient of Jaccard, and the overlap function. (Contains 28 references.) (LRW)
Descriptors: Information Retrieval, Mathematical Formulas, Measurement Techniques, Models
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Zhang, Jin; Korfhage, Robert R. – Journal of the American Society for Information Science, 1999
Presents a visualization tool for information retrieval that can display two different similarity measures, angle and distance, in the same space. Discusses the visual display of information-retrieval evaluation models and develops a new retrieval means based on the visual retrieval tool, the controlling bar. (Author/LRW)
Descriptors: Evaluation Methods, Information Retrieval, Mathematical Formulas, Measurement Techniques
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Horng, Jorng-Tzong; Yeh, Ching-Chang – Information Processing & Management, 2000
Proposes a novel approach to automatically retrieve keywords and then uses genetic algorithms to adapt the keyword weights. Discusses Chinese text retrieval, term frequency rating formulas, vector space models, bigrams, the PAT-tree structure for information retrieval, query vectors, and relevance feedback. (Author/LRW)
Descriptors: Algorithms, Chinese, Information Retrieval, Keywords
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Egghe, Leo; Rousseau, Ronald – Journal of the American Society for Information Science, 1998
Discusses topological aspects of theoretical information retrieval, including retrieval topology; similarity topology; pseudo-metric topology; document spaces as topological spaces; Boolean information retrieval as a subsystem of any topological system; and proofs of theorems. (LRW)
Descriptors: Documentation, Information Retrieval, Mathematical Formulas, Proof (Mathematics)
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Bollmann-Sdorra, Peter; Raghavan, Vijay V. – Journal of the American Society for Information Science, 1998
Discussion of the vector space model and properties of document and query spaces focuses on the proof that requiring term independence to hold in the query space is inconsistent with the goal of achieving better performance by means of weighted retrieval. Proofs are provided. (Author/LRW)
Descriptors: Documentation, Information Retrieval, Mathematical Formulas, Proof (Mathematics)
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Congos, Dennis – Journal of College Student Retention, 2002
Seeks to increase awareness of the ability of supplemental instruction (SI) programs to generate retained tuition revenue for colleges and universities far beyond the costs of the program. Presents formulas to help prospective and existing SI programs determine the amount of retained revenue SI can generate for individual institutions. (EV)
Descriptors: Higher Education, Income, Mathematical Formulas, Remedial Programs
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McBrien, Peter; Poulovassilis, Alexandra – Information Systems, 1998
Discussion of methodologies for the semantic integration of databases focuses on formalizing the notion of schema equivalence and the schema integration process. Topics include common data model; the Entity-Relationship (ER)model; transformation of ER models; transformational, mapping, and behavioral schema equivalence; and knowledge-based…
Descriptors: Databases, Linguistic Theory, Mathematical Formulas, Models
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Blanco, Jose Miguel; Goni, Alfredo; Illarramendi, Arantza – Information Systems, 1999
Discussion of data repositories available in global information systems focuses on facilitating access by providing semantic views. Highlights include the mapping relation; syntax and semantics of the mapping; query formulation and processing; terminological systems for semantic views; and relational algebraic expressions. (LRW)
Descriptors: Algebra, Databases, Global Approach, Information Systems
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