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A storage and access manager for ill-structured data
Database management systems are powerful tools for processing large volumes of structured, or normalized, data. Much of the data to be stored in computer systems, however, differs from normalized data in both its logical uses and the storage structure required for its effective management. For instance, Van Rijsbergen (1979) distinguishes database retrieval from information retrieval (IR)—the retrieval of references to text—by comparing the following logical characteristics of IR systems to database management systems: IR Systems employ partial (vs. exact) matching; they are built on an underlying probabilistic (vs. deterministic) model; they classify information on a polythetic (vs. monothetic) basis, and queries are incompletely (vs. completely) specified. Similarly, other forms of relatively ill-structured data such as semantic networks [15]—which require property inheritance, and production rules—which must be joined in logical chains also differ in their logical use from normalized record structures.
Justification of printed music
There is increasing interest in the use of computer systems for editing and printing sheet music [3, 19]. Music processing lags far behind text processing because of the complexities of music notation. Most music published today is still laid out by hand; while computers may be used, decisions about music-symbol placement are made by people. Much research remains to be done into computational methods of encoding the myriad rules of music notation. Individual rules are not difficult to formulate; it is the complex interaction among rules which is difficult to describe and control. In this article we focus on one aspect of music notation: the horizontal spacing of music to produce a right- and left- justified result.
Diffusion in computing networks: the case of BITNET
Using BITNET as a model, the author examines the adoption pattern of computing networks from the perspectives of innovation diffusion theory and economics.
An object-oriented relational database
A relational DBMS and an object-oriented programming language can be combined to yield a surprisingly effective OO-DBMS for many applications.
SCISOR: extracting information from on-line news
The future of natural language text processing is examined in the SCISOR prototype. Drawing on artificial intelligence techniques, and applying them to financial news items, this powerful tool illustrates some of the future benefits of natural language analysis through a combination of bottom-up and top-down processing.
Traditional dialogue design applied to modern user interfaces
Several examples show that principles for the design of usable dialogues are just as important for modern graphical user interfaces as they are for traditional text-based interfaces.
Economic analysis of microcomputer hardware
Economic analysis of the hardware characteristics of the personal computer segment of the microcomputer market indicates that the variables that most affect cost are the bundle of attributes offered by the micros. Interestingly, certain technological characteristics found to be important explanatory variables for cost in larger computers were not found to be significant for micros.
Physical design equivalencies in database conversion
As relational technology becomes increasingly accepted in commercial data processing, conversion of some of the huge number of existing navigational databases to relational databases is inevitable. It is thus important to understand how to recognize physical design modifications and enhancements in the navigational databases and how to convert them to equivalent relational terms as applicable.
A very fast substring search algorithm
This article describes a substring search algorithm that is faster than the Boyer-Moore algorithm. This algorithm does not depend on scanning the pattern string in any particular order. Three variations of the algorithm are given that use three different pattern scan orders. These include: (1) a “Quick Search” algorithm; (2) a “Maximal Shift” and (3) an “Optimal Mismatch” algorithm.
Agenda: a personal information manager
The free-form, evolving, personal information that people deal with in the course of their daily activities requires more flexible data structures and data management systems than tabular data structures provide. A tool for managing personal information must conveniently handle freetextual data; allow for structure to evolve gracefully as the database grows; represent unnormalized data; and support data entry through database views. We have designed a new type of database that serves these needs—“item/category” database—and realized this design in a commercial personal computer software product named “Agenda.”
Object subclass hierarchy in SQL: a simple approach
The object subclass hierarchy is a useful way of modeling property and behavior inheritance. It can be implemented on a relational DBMS using views.
Fast hashing of variable-length text strings
Using only a few simple and commonplace instructions, this algorithm efficiently maps variable-length text strings small integers.
Concurrent operations on extendible hashing and its performance
Extendible hashing is a dynamic data structure which accommodates expansion and contraction of any stored data efficiently. In this article, an algorithm has been developed for managing concurrent operations on extendible hashing by achieving optimal memory utilization by supporting directly expansion and contraction, page split, and merge. The results of this study have been encouraging in the sense that it seems to provide a higher degree of concurrency compared to other algorithms on an extendible hash file.
Typographic style is more than cosmetic
There is disagreement about the role and importance of typographic
style (source code formatting and commenting) in program comprehension.
Results from experiments and opinions in programming style books are
mixed. This article presents principles of typographic style consistent
and compatible with the results of program comprehension studies. Four
experiments demonstrate that the typographic style principles embodied
in the book format significantly aid program comprehension and reduce
maintenance effort.
—Authors' Abstract
An AI-based approach to machine translation in Indian languages
Primarily illustrated as an approach to translate the Indian languages, a focus on AI techniques for building semantic representational structures of sentences is presented.
Building bilingual microcomputer systems
In the Arab world the need for bilingual microcomputer systems is ever increasing. In addition to the ability to process the Arabic and English scripts, an ideal system should support the use of existing applications with Arabic data and the access to the system facilities through Arabic interfaces. The Integrated Arabic System (IAS) was developed to study the feasibility of building such systems using existing microcomputers and software solutions.
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