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Showing 1,231 to 1,245 of 2,350 results Save | Export
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Egghe, L.; Ravichandra Rao, I. K. – Information Processing and Management, 1992
Discusses the shape of the obsolescence function based on the age data for cited journals. An analysis of the aging function is discussed; and statistical fits and mathematical explanations are illustrated, including the model of Avramescu, the Negative Binomial Distribution, the Weibull distribution, the lognormal distribution, and the utility…
Descriptors: Citations (References), Mathematical Formulas, Obsolescence, Scholarly Journals
Petry, Frederick E.; And Others – Proceedings of the ASIS Annual Meeting, 1993
Describes an approach that combines concepts from information retrieval, fuzzy set theory, and genetic programing to improve weighted Boolean query formulation via relevance feedback. Highlights include background on information retrieval systems; genetic algorithms; subproblem formulation; and preliminary results based on a testbed. (Contains 12…
Descriptors: Algorithms, Information Retrieval, Mathematical Formulas, Online Systems
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Gordon, Michael D.; Lenk, Peter – Journal of the American Society for Information Science, 1992
Discussion of probabilistic information retrieval systems highlights the probability ranking principle and discusses when the standard retrieval policy is optimal. Topics discussed include calibration and refinement; independent assessment of relevance by the inquirer; certainty about the computed probabilities of relevance; and confidence and…
Descriptors: Information Retrieval, Mathematical Formulas, Probability, Relevance (Information Retrieval)
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Sichel, H. S. – Information Processing and Management, 1992
Discusses the use of the generalized inverse Gaussian-Poisson (GIGP) distribution in bibliometric studies. The main types of size-frequency distributions are described, bibliometric distributions in logarithms are examined; parameter estimation is discussed; and goodness-of-fit tests are considered. Examples of applications are included. (17…
Descriptors: Bibliometrics, Goodness of Fit, Logarithms, Mathematical Formulas
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Burrell, Quentin L. – Information Processing and Management, 1992
Investigates the Leimkuhler curve and the Gini index from a probabilistic viewpoint for studying the concentration of bibliometric distributions. The importance of the time parameter and the special nature of the "nonproducers" in bibliometric studies are examined, standard models of bibliometric processes are described, and further…
Descriptors: Bibliometrics, Mathematical Formulas, Mathematical Models, Measurement Techniques
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Lee, Joon Ho; And Others – Journal of Documentation, 1993
Discussion of document ranking methods to calculate the conceptual distance between a Boolean query and a document focuses on the Knowledge-Based Extension Boolean Model which evaluates weighted queries and documents effectively and avoids problems of previous methods. Semantic networks are discussed, and is-a hierarchies are explained. (21…
Descriptors: Documentation, Information Retrieval, Mathematical Formulas, Models
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Jarvelin, Kalervo; Niemi, Timo – Journal of the American Society for Information Science, 1993
Shows how deductive data management techniques can be applied to the utilization of data value classifications in information retrieval. A representation of classifications which supports transitive computation is defined, and an operation-oriented deductive query language tailored for classification-based deductive information retrieval in fact…
Descriptors: Classification, Database Management Systems, Databases, Deduction
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Buckland, Michael; Gey, Fredric – Journal of the American Society for Information Science, 1994
Examines the relationship between recall and precision in information retrieval performance and explains why a trade-off between them is unavoidable under certain conditions. Topics discussed include the theoretical behavior of precision and recall; mathematics of the recall curve; an example using a test document collection; and two-stage…
Descriptors: Information Retrieval, Mathematical Formulas, Online Systems, Performance Factors
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Boughanem, M.; Chrisment, C.; Soule-Dupuy, C. – Information Processing & Management, 1999
Presents a relevance-feedback strategy that improves the effectiveness of information-retrieval systems based on back-propagation of the relevance of retrieved documents using an algorithm developed in a neural approach. Describes a neural information-retrieval model and reports results obtained with the algorithm in three different environments.…
Descriptors: Algorithms, Information Retrieval, Mathematical Formulas, Models
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Rousseau, Ronald – Canadian Journal of Information and Library Science, 1998
Presents definitions of convolutions, mathematical operations between sequences or between functions, and gives examples of their use in information science. In particular they can be used to explain the decline in the use of older literature (obsolescence) or the influence of publication delays on the aging of scientific literature. (Author/LRW)
Descriptors: Information Science, Mathematical Concepts, Mathematical Formulas, Obsolescence
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Guang, Yu; Daren, Yu; Yihong, Rong – Information Processing & Management, 2000
Describes two mathematical models of the periodical publishing process based on a theoretical analysis. Discusses the publishing process for periodical literature, explains the continuous model and the discrete model, presents partial differential equations, and demonstrates the adaptability and the validity of the models. (LRW)
Descriptors: Differential Equations, Mathematical Formulas, Mathematical Models, Publishing Industry
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Ribando, Robert J.; O'Leary, Gerald W. – Computer Applications in Engineering Education, 1998
Describes a PC-based teaching module designed to instruct engineering students in transient one-dimensional conduction heat transfer analysis. The discussion considers problem formulation, nondimensionalization, discretization, numerical stability and the time-step restriction, program operation, and program verification. (MES)
Descriptors: Computer Assisted Instruction, Courseware, Engineering Education, Higher Education
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Michel, Christine – Information Processing & Management, 2001
Discussion of information retrieval focuses on a general method for the construction of measures of similarity taking into account the rank of presentation of the document, called ordered similarity measures. Presents an experimental evaluation used to quantify the filtering impact of a system and discusses recall and precision. (Author/LRW)
Descriptors: Evaluation Methods, Information Retrieval, Mathematical Formulas, Measurement Techniques
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Yang, Yiming; Wilbur, John – Journal of the American Society for Information Science, 1996
Studies aggressive automated word removal in text categorization in large databases based on corpus statistics to reduce the noise in free texts and to enhance the computational efficiency of categorization. Topics include stop word identification, categorization methods for comparison, tests on four document collections, and evaluation…
Descriptors: Comparative Analysis, Databases, Evaluation Methods, Information Retrieval
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Geldenhuys, Gerhard; Human, Lezanne – Journal of the American Society for Information Science, 1996
Describes an index of cohesion for the investigation of communication between authors or academic units and compares it with the Brillouin-Shaw index. Communication and cooperation between researchers is discussed and graph theory is explained, especially cooperation graphs. (Author/LRW)
Descriptors: Authors, Comparative Analysis, Cooperation, Departments
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