Abstract: Publisher Summary In the area of programming, the power of languages helps to shape the thoughts on computation and direct them along one path rather than another, and create one particular set of mental pictures in preference to others. The chapter observes that there exist a large number of language proposals for hardware specification at various levels of abstraction. This chapter examines in detail the languages for the description of computer hardware, with emphasis on architecture descriptions. The chapter considers the nature of languages that can be used for the design and description of computer hardware systems, commonly referred as computer design and description languages (CDDLs). Further applicability of these languages depends largely on the development of appropriate language-based design methods and automated systems. With continuing advances, a shift in emphasis from language-design issues to the problem of methodologies, systems, and environments for the systematic, rigorous, and verifiable design and implementation of computer architectures can be noticed.

Abstract: Publisher Summary Distributed database systems are essentially built on top of a distributed architecture. This chapter focuses on the problem of query optimization in distributed database systems. The chapter presents the basic concepts of query optimization and reviews the current methods for centralized systems. Distributed query processing and the semi-join operation, central to distributed query processing, is presented. The chapter discusses the three major query evaluation strategies. These methods include the algorithms used in SDD-1, in Distributed INGRES, and those proposed by Hevner-Yao. A general framework for query optimization is also discussed. The objective function of most of the distributed query optimization strategies is the minimization of the use of network resources. Transformation of the query to be optimized into disjunctive normal form and initial parallel local processing are considered to be beneficial, and are always performed. The chapter observes that the basic optimization problem is the evaluation of distributed joins, which require transmissions among sites.

Abstract: Publisher Summary Library automation systems and networks refers to the use of computers, either stand-alone or in a shared manner, to increase the productivity of library personnel, and to provide new and improved library services to patrons. This chapter focuses on the advances in application of computers and related technologies to library operations achieved in the last decade. Library operations can be divided into three major categories—namely, the administration and management, technical services, and public services. Each of these categories, in turn, can be divided into a number of specific functional areas. The chapter discusses these library functions in regard to the application of computer technology to their support. The chapter also provides background information on the organization and operation of libraries, on the assimilation of technology into libraries, and on some efforts to automate library processes. The current status of library automation and networking along with some important standards that have a bearing onlibrary automation and networking are also examined.

Abstract: Publisher Summary This chapter examines microcomputer applications. The chapter describes the present scenario and explores future advances. The chapter evaluates microcomputer applications under certain criteria of suitability or acceptability. In specific, it is noted that microcomputer is small in price, size, weight, power consumption, heat production, and probability of malfunction. The miniaturization of the microcomputer allows it to be incorporated in objects that are very small. The future of microcomputers and digital communications is interconnected; it is only through the joint success of each that the true promise of this era can be realized. The chapter considers and emphasizes on the concept of integration in context to computing and communications. In order for a computer to be most effective it should be integrated into its total environment, which includes the electronic, physical, and human spheres. There is a strong potential for microcomputers to have a revolutionary impact upon human society. The rapidity of the integration of these computers into society can be controlled by economics, human attitudes, and the characteristics of particular applications.

Abstract: The structure of the universe as an environment where traces exist of the seed fluctuations from which galaxies formed is studied. The evolution of the density fluctuation modes that led to the eventual formation of matter inhomogeneities is reviewed, How the resulting clumps developed into galaxies and galaxy clusters acquiring characteristic masses, velocity dispersions, and metallicities, is discussed. Tests are described that utilize the large scale structure of the universe, including the dynamics of the local supercluster, the large scale matter distribution, and the anisotropy of the cosmic background radiation, to probe the earliest accessible stages of evolution. Finally, the role of particle physics is described with regard to its observable implications for galaxy formation.

Abstract: Publisher Summary Chemistry is an experimental science, based on the laws of physics and using the language of mathematics augmented by graphics. It addresses to the properties of materials, including those important to the life process from an atomic and molecular perspective. This chapter describes a set of five complementary areas—namely, chemical education and computer, computer in the chemical laboratory, the modeling of matter from a molecular perspective, chemical information, and the chemistry establishment. Chemistry is international in scope. The common and accepted language of chemists provides an international communication network. Computers in the world of chemistry offer completely new possibilities for quantitatively handling molecules consisting of many nuclei and electrons, for modeling of complex reactions, and for banking and retrieving tremendous amounts of data and information of all kinds. The chemist, on entering the world of computing, not only becomes more potent as a chemist, but can also discover new channels of communication with people working in other disciplines.

Abstract: The recent observational evidence on the evolution of galaxies is reviewed and related to the framework of current ideas for galaxy formation from primordial density fluctuations. Recent strong evidence for the evolution of the stellar population in ellipticals is presented, as well as evidence that not all ellipticals behave as predicted by any simple theory. The status of counts of faint galaxies and the implications for the evolution of spirals is discussed, together with a discussion of recent work on the redshift distribution of galaxies at faint magnitudes and a spectroscopic investigation of the Butcher-Oemler blue cluster galaxies. Finally a new picture for the formation and evolution of disk galaxies which may explain most of the features of the Hubble sequence is outlined.

Abstract: Rule-based expert systems are surveyed. The most important considerations are representation and inference. Rule-based systems make strong assumptions about the representation of knowledge as conditional sentences and about the control of inference in one of three ways. The problem of reasoning with incomplete or inexact information is also discussed, as are several other issues regarding the design of expert systems.