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Über dieses Buch

This volume, the eighth of a continuing series on information systems science, presents five timely topics which are of current interest in this growing field. In each chapter, an attempt is made to familiarize the reader with some basic background information on the advances discussed, so that this volume may be used independently or in conjunction with the previous volumes. The emphasis in this volume is centered upon file or­ ganization and performance evaluation, computational semantics, digital control, clustering analysis, and geometric modeling. Chapter I presents a comprehensive survey of file organization. In this chapter, Gudes and Ganesh discuss performance evaluation, imple­ mentation considerations, relationship to database models, and performance tradeoffs of various file organizations. The semantics of programming languages was discussed in Volume 2 of this series. This topic is revisited by Culik II and Farah from a different point of view. Chapter 2 is concerned with linked forest manipulation and models for formal description of a programming language. Linked trees reveal syntactical properties of a programming language and provide data structures for describing com­ putational semantics.



Chapter 1. A Survey of File Organizations and Performance

The importance of information systems in today’s society is well recognized. Their users may vary from government executives and army generals to bank tellers and library patrons. Users’ requirements for an information system may vary significantly, but they all have at least two common goals. That is, they would like to improve performance and reduce cost.
Ehud Gudes, S. Ganesh

Chapter 2. Linked Forest Manipulation Systems—A Tool for Computational Semantics

Linked trees, as data structures for describing the computational semantics of programming languages, were introduced in reference 1, and seem to be the best known data structure type for that task. The definitional model introduced there has been used to describe concisely and in readable form several complete programming languages (algol 60(2), altran (3), lucid (4), and protel (5)) and to prove the correctness of an interpreter for lucid.(4) Here, we give a readable informal description of the rewriting systems for linked trees, and a new, somewhat simplified, and algebraically-oriented formal definition of linked forest manipulation systems and a description of their application to computational semantics. An algol-like language ALG and the λ-calculus are used as examples.
Karel Culik, Mansour Farah

Chapter 3. Software Development for Digital Control

The use of computers in control is not a new phenomenon; however, in the past, the number of individuals involved in developing software for digital control systems has been relatively small and applications generally have been limited to large plants. The current availability of very inexpensive computing power in microcomputers and the continued cost reduction and performance improvement of minicomputers has brought the many advantages of digital control within the economic range of even the most limited applications. At the same time, the requirements for increased energy efficiency, pollution control, and reliability have expanded the demand for sophisticated control, particularly in the automotive and appliance industries.(1–3) In some cases the advancing technology has created new classes of products such as active optical instruments(4) and sophisticated toys and other consumer products.
Randall Paul Shumaker

Chapter 4. Clustering Analysis and Its Applications

Clustering analysis(1–4) is a newly developed computer-oriented data analysis technique. It is a product of many research fields: statistics, computer science, operations research, and pattern recognition. Because of the diverse backgrounds of researchers, clustering analysis has many different names. In biology, clustering analysis is called “taxonomy”.(5,6) In pattern recognition(7–15) it is called “unsupervised learning.” Perhaps the most confusing name of all, the term “classification” sometimes also denotes clustering analysis. Since classification may denote discriminant analysis, which is totally different from clustering analysis, it is perhaps important to distinguish these two terms.
R. C. T. Lee

5. An Introduction to Geometric Modeling and Its Applications in Mechanical Design and Production

Geometry plays a crucial role in the design and production of discrete mechanical goods. In early times artisans “carried geometry in their heads” or relied on physical models and analogues. The rise of mass production and job specialization led to the adoption of engineering drawings as a medium for geometric specification, and recently the advent of computers, NC (numerically controlled) plotters, and CRT displays has led to a growing wave of “computerization” of drafting activities.
A. A. G. Requicha, H. B. Voelcker


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