A query language which is suitable for use with a relational data base system is discussed. The language is developed as an extension of ideas found in programming languages as well as relational calculus. The development is a step towards the integration of programming languages, query languages, and data base systems. The language offers a…

Addressing the problem of protecting confidential information and data stored in computer databases from access by unauthorized parties, this paper details coding schemes which present such astronomical work factors to potential code breakers that security breaches are hopeless in any practical sense. Two procedures which can be used to encode for…

This paper is concerned with providing automatically generated online explanations to the user of a user interface or "tool" about what the interface can and cannot do, and what parameters or options are available or required with a given command. The COUSIN interface system, developed at Carnegie-Mellon, supplies a cooperative…

This is a progress report on a project attempting to design a system of compacting text for storage appropriate to disc oriented demand searching. After noting a number of previously designed methods of compression, it offers a tentative solution which couples a dictionary of most frequent character-strings with a set of variable-length codes. The…

The computer language FOL is intended to facilitate the implementation of file organizations for information storage and retrieval systems. In many information storage and retrieval applications the designer, initially, does not know how best to organize a data base for efficient retrieval and ease of updating and modifying. It is felt that FOL…

A Data Element Dictionary/Directory (DED/D) is a software tool that is used to control and manage data elements in a uniform manner. It can serve data base administrators, systems analysts, software designers, and programmers by providing a central repository for information about data resources across organization and application lines. This…

Although the indispensibility of access control mechanisms in data secure systems has been recognized, there is a need for more subtle protection and refined control mechanisms. This report describes context protection mechanisms which enable the same data unit to be protected differently in different contexts, the differences being determined by…

Examines usage patterns of ELHILL retrieval program of National Library of Medicine's MEDLARS system. Based on sample of 6,759 searches, the study analyzes frequency of various commands, classifies messages issued by system, and investigates searcher error rates. Suggestions for redesigning program and query language are noted. Seven references…

A new theory of sign structure is proposed which explains the syntactic, semantic and pragmatic classification of signs. The theory comprises in part a language capable of relating studies of information processes across a range of disciplines, including communication science psychology, computer science, and linguistics. The power and utility of…

The Privacy Act of 1974 (PL 93-579) and guidelines for its implementation impose requirements on Federal agency personal record-keeping practices. This report presents an implementation strategy for the administration of certain Privacy Act requirements with the use of current data base management systems. These requirements are analyzed in the…

Conducted to design software partitioning techniques for use by the Air Force to partition a large flight simulator program for optimal execution on alternative configurations, this study resulted in a mathematical model which defines characteristics for an optimal partition, and a manually demonstrated partitioning algorithm design which…

The aims of the first phase of the Statistics Indexing and Retrieval (STIR) Project have been: (1) to define the types and sources of statistics which should be within the scope of an operational indexing system for statistical sources; (2) to analyze the use made of statistical sources; and (3) to consider the intellectual, structural, and…

Arguments presented against securing computer programs by copyright are centered on the question of whether computer programs qualify under the U.S. Constitutional meaning as "works of authorship," which may be protected by copyright. The possibility that the protection of computer programs by copyright might have an undesirable impact…

Procedures are outlined for estimating changes in parenthood and marital status for respondents of the National Longitudinal Study of the High School Class of 1972 (NLS). Seven key variables that summarize the information on parenthood and marital status are estimated: number of children as of the first week of October in 1973, 1974, and 1976, a…

The Occupational Shortages Reporting System (OSRS) is a computerized system developed to produce quick and accurate reports on occupational shortages for given time periods and given occupations in Texas. The system's salient features are: easy and fast retrievability of information; expandability of the data base (from the present 1,254…