A Formal Model Of Visualization In Computer Graphics Systems

The 18 research articles of this volume discuss the major themes that have emerged from mathematical and statistical research in the epidemiology of HIV. The opening paper reviews important recent contributions. Five sections follow: Statistical Methodology and Forecasting, Infectivity and the HIV, Heterogeneity and HIV Transmission Dynamics, Social Dynamics and AIDS, and The Immune System and The HIV. In each, leading experts in AIDS epidemiology present the recent results. Some address the role of variable infectivity, heterogeneous mixing, and long periods of infectiousness in the dynamics of HIV; others concentrate on parameter estimation and short-term forecasting. The last section looks at the interaction between the HIV and the immune system.

State of the Art in Computer Graphics Aspects of Visualization This is the fourth volume derived from a State of . . . the Art in Computer Graphics Summer Institute. It represents a snapshot of a number of topics in computer graphics, topics which include visualization of scientific data; modeling; some aspects of visualization in virtual reality; and hardware architectures for visu alization. Many papers first present a background introduction to the topic, followed by discussion of current work in the topic. The volume is thus equally suitable for nonspecialists in a particular area, and for the more experienced researcher in the field. It also enables general readers to obtain an acquaintance with a particular topic area sufficient to apply that knowledge in the context of solving current problems. The volume is organized into four chapters - Visualization of Data, Modeling, Virtual Reality Techniques, and Hardware Architectures for Visualization. In the first chapter, Val Watson and Pamela Walatka address the visual aspects of fluid dynamic computations. They discuss algorithms for function-mapped surfaces and cutting planes, isosurfaces, particle traces, and topology extractions. They point out that current visualization systems are limited by low information transfer bandwidth, poor response to viewing and model accuracy modification requests, mismatches between model rendering and human cognitive capabilities, and ineffective interactive tools. However, Watson and Walatka indicate that proposed systems will correct most of these problems.

Today one of the hardest parts of computer aided design or analysis is first modeling the design, then recording and verifying it. For example, a typical vehicle such as a tank, automobile, ship or aircraft might be composed of tens of thousands of individual parts. Many of these parts are composed of cylinders, flats, and simple conic curves and surfaces such as are amenable to modeling using a constructive solid geometry (CSG) approach. However, especially with the increasing use of composite materials, many parts are designed using sculp tured surfaces. A marriage of these two techniques in now critical to continued development of computer aided design and analysis. Further, the graphical user interfaces used in most modeling systems are at best barely adequate to the required task. Critical work on these interfaces is required to continue pushing back the frontiers. Similarly, once the design is modeled, how are the varied and diverse pieces stored, retrieved, and modified? How are physical interferences prevented or eliminated? Although considerable progress has been made, there are still more questions and frustrations than answers. One of the fundamental problems of the 1990s is and will continue to be modeling. The second problem is interpretation. With the ever increasing computational power available, our ability to generate data far exceeds our ability to interpret, understand, and utilize that data.

"Visualization in scientific computing is getting more and more attention from many people. Especially in relation with the fast increase in computing power, graphic tools are required in many cases for interpreting and presenting the results of various simulations, or for analyzing physical phenomena." "This volume contains a selection of 18 papers presented at the first workshop organized by the Eurographics Working Group on Visualization in Scientific Computing, held in France in 1991. The workshop included sessions on the specific needs for visualization in computational sciences, the importance and difficulties of using standards in visualization software, reference models and distributed graphics systems, application systems, methods for representing 2D or 3D scalar fields and volume rendering, and user-computer interactions. The papers in the volume are organized into five parts: general requirements; formal models, standards, and distributed graphics; applications; rendering techniques; and interaction."--BOOK JACKET.Title Summary field provided by Blackwell North America, Inc. All Rights Reserved

The stepwise refinement method postulates a system construction route that starts with a high-level specification, goes through a number of provably correct development steps, and ends with an executable program. The contributions to this volume survey the state of the art in this extremely active research area. The world's leading specialists in concurrent program specification, verification, and the theory of their refinement present latest research results and surveys of the fields. State-based, algebraic, temporal logic oriented and category theory oriented approaches are presented. Special attention is paid to the relationship between compositionality and refinement for distributed programs. Surveys are given of results on refinement in partial-order based approaches to concurrency. A unified treatment is given of the assumption/commitment paradigm in compositional concurrent program specification and verification, and the extension of these to liveness properties. Latest results are presented on specifying and proving concurrent data bases correct, and deriving network protocols from their specifications.

This volume presents the proceedings of a workshop on parallel database systems organized by the PRISMA (Parallel Inference and Storage Machine) project. The invited contributions by internationally recognized experts give a thorough survey of several aspects of parallel database systems. The second part of the volume gives an in-depth overview of the PRISMA system. This system is based on a parallel machine, where the individual processors each have their own local memory and communicate with each other over a packet-switched network. On this machine a parallel object-oriented programming language, POOL-X, has been implemented, which provides dedicated support for database systems as well as general facilities for parallel programming. The POOL-X system then serves as a platform for a complete relational main-memory database management system, which uses the parallelism of the machine to speed up significantly the execution of database queries. The presentation of the PRISMA system, together with the invited papers, gives a broad overview of the state of the art in parallel database systems.

Currently, the field of information systems technology is rapidly extending into several dimensions. There is the semantic dimension (including object orientation, data deduction and extended knowledge representation schemes), there is improved systems integration, and there are new tools. All these extensions aim to provide semantically richer and better engineered information systems that allow for more adequate and complete representations and thus extend the effective use of database technology to a wider class of applications. Database researchers and developers, whether they are committed to application or to system construction, are convinced that next-generation information system technology will be heavily determined by a handful of new concepts that they have to understand and work out in detail now. This volume concentrates on the following topics: - Extended data types and data models, database programming languages; - Rule-based data deduction, expert systems, knowledge bases; - Object orientation and semantic data modelling; - DB application development, methodologies and tools; - Interface technology, parallelism, interoperability, ...; - New database applications.