Two different directory structuring techniques--division hash technique and a hydrid technique--are compared for the same set of keys with directories of from 10,000 to 100,000 unique keys. Retrieval costs, in terms of the number of accesses of secondary storage required to retrieve the keys, are considered in detail. (Author)

Traditional and table-driven methods of editing input data for a data-storage system are compared. An application of table-driven input editing is described for a high-volume, multiple-format, clinical data-base. (Author)

Conversion of the Chemical Abstract Service scientific literature data base from Standard Distribution Format to a center-oriented file format, STF, is described. A tape file format is described in which variable length logical records, possibly longer than the blocksize, may be stored safely. (7 references) (Author/NH)

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)

Advantages of the Berkeley Mass Storage System (MSS) for information retrieval other than its size are: high serial-read rate, archival data storage; and random-access capability. By use of this device, the search cost in an SDI system based on the Nuclear Science Abstracts" data base was reduced by 20 percent. (6 references) (Author/NH)

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…

Because experience with large information retrieval (IR) and database management (DBM) systems has shown that they are not adequate for the handling of textual material, two Swedish companies--Paralog and AU-System Network--have joined in a venture to develop a software package which combines features from IR and DMB systems to form a Text Data…

Describes a system for the management and analysis of chemical structure-biological activity data wherein the chemical structures, encoded in Wiswesser Line Notation, are checked for accuracy, stored, and retrieved by computer. Unification of description and activity of bio-systems. Structuring data files. (Author)

Reports on a series of programs that have been developed to process data bases, consisting of textual items, and to index and arrange (classify) the data items in accordance with an automatically generated classification system. (Author)

Describes the use of a microcomputer system to generate a personal database of books read by adding titles, displaying title/author information, and editing title/author information and discusses the system design, i.e., file structure (author index, book index, book, author), the main driver, function subroutines, and screen subroutines. (EJS)

Surveys the technology of database software and hardware, describing some of the principal issues related to the user's view of data, sharing, concurrent access, security, and integrity. (JN)

Modeled on public databases such as Lockheed and SDC, the information system described in this report was utilized in the creation of in-house databases in the Mobay Chemical Corporation's special library in Pittsburgh. Using IBM's Storage and Information Retrieval System (STAIRS), Mobay created two databases: one to hold product information, the…

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…

The Information Sciences section of ITT Research Institute (IITRI) has developed a Computer Search Center and is currently conducting a research project to explore computer searching of a variety of machine-readable data bases. The Center provides Selective Dissemination of Information services to academic, industrial and research organizations…