Analyzes computer terminal memory performance in terms of overflow probability and average queueing delay, and presents new method to derive a closed expression for data arrivals with Erlangly distributed interarrival times and an approach to derive steady state probability expressions of the terminal memory content process. Twenty references are…

Presents a system model for transmission of input data that is coming from terminals of users in a limited user resource-sharing environment. Performance of a mini/microcomputer receiving mixture of picture-phone terminal data is analyzed with constant service times, synchronous transmission, and single-server interruptions through first-order…

False drops occur in a system of random superimposed coding for edge-notched, punched, and feature cards. Formulae for the false dropping fraction are derived, and figures and tables are given for the calculated values in the most popular scheme. (Author/LS)

A new method for concentrating keywords of a thesaurus, based on a mathematical study of the distribution of characters in a defined natural language. (Author/KP)

Calculations of storage requirements for retrieval systems using inverted files. Problem of minimal storage requirements for inverted file is solved for different index term distributions. (Author/KP)

Brief discussion of state-of-the-art of modeling complex information systems distinguishes between macrolevel and microlevel modeling of such systems. Network layout and hierarchical system models, simulation, information acquisition and dissemination, databases and information storage, and operating systems are described and assessed. Thirty-four…

Examines through a series of mathematical models (theorems, descriptions, and examples), properties and operations on inverted files, which are used in an information retrieval system based on thesaurus with weighted descriptors. (CWM)

Analyzes the use of weights to denote a query representation and/or the indexing of a document as a generalization of a Boolean retrieval system. Criteria are given for the functions used to evaluate the relevance of the records to a specific query and a new evaluation approach is suggested. (CWM)

Presents a new method of document retrieval based on the fundamental operations of fuzzy set theory. Basic notions are introduced. Then the syntax and semantics of the proposed language for document retrieval is given, and an algorithm allocating documents to particular queries is described and its properties are discussed. (Author/CWM)