At first glance the concepts of time and of Petri nets are quite contrary: while time determines the occurrences of events in a system, classic Petri nets consider their causal relationships and they represent events as concurrent systems. But if we take a closer look at how time and causality are intertwined we realize that there are many possible ways in which time and Petri nets interact. This book takes a closer look at three time-dependent Petri nets: Time Petri nets, Timed Petri nets, and Petri nets with time windows.

The author first explains classic Petri nets and their fundamental properties. Then the pivotal contribution of the book is the introduction of different algorithms that allow us to analyze time-dependent Petri nets. For Time Petri nets, the author presents an algorithm that proves the behavioral equivalence of a net where time is designed once with real and once with natural numbers, so we can reduce the state space and consider the integer states exclusively. For Timed Petri nets, the author introduces two time-dependent state equations, providing a sufficient condition for the non-reachability of states, and she also defines a local transformation for converting these nets into Time Petri nets. Finally, she shows that Petri nets with time-windows have the ability to realize every transition sequence fired in the net omitting time restrictions.

These classes of time-dependent Petri nets show that time alone does not change the power of a Petri net, in fact time may or may not be used to force firing. For Time Petri nets and Timed Petri nets we can say that they are Turing-powerful, and thus more powerful than classic Petri nets, because there is a compulsion to fire at some point in time. By contrast, Petri nets with time-windows have no compulsion to fire, their expressiveness power is less than that of Turing-machines.

This book derives from advanced lectures, and the text is supported throughout withexamples and exercises. It issuitable for graduate courses in computer science, mathematics, engineering, and related disciplines, and as a reference for researchers."

Rapid increases in chip complexity, increasingly faster clocks, and the proliferation of portable devices have combined to make power dissipation an important design parameter. The power consumption of a digital system determines its heat dissipation as well as battery life. For some systems, power has become the most critical design constraint. Computer-Aided Design Techniques for Low Power Sequential Logic Circuits presents a methodology for low power design. The authors first present a survey of techniques for estimating the average power dissipation of a logic circuit. At the logic level, power dissipation is directly related to average switching activity. A symbolic simulation method that accurately computes the average switching activity in logic circuits is then described. This method is extended to handle sequential logic circuits by modeling correlation in time and by calculating the probabilities of present state lines. Computer-Aided Design Techniques for Low Power Sequential Logic Circuits then presents a survey of methods to optimize logic circuits for low power dissipation which target reduced switching activity. A method to retime a sequential logic circuit where registers are repositioned such that the overall glitching in the circuit is minimized is also described. The authors then detail a powerful optimization method that is based on selectively precomputing the output logic values of a circuit one clock cycle before they are required, and using the precomputed value to reduce internal switching activity in the succeeding clock cycle. Presented next is a survey of methods that reduce switching activity in circuits described at the register-transfer and behavioral levels. Also described is a scheduling algorithm that reduces power dissipation by maximising the inactivity period of the modules in a given circuit. Computer-Aided Design Techniques for Low Power Sequential Logic Circuits concludes with a summary and directions for future research.

provides systematic solutions from formal test theory to automated test description methods, automated simulation test environment construction verifies the effectiveness of the theories, technologies and methods

Mastering interoperability in a computing environment consisting of different operating systems and hardware architectures is a key requirement which faces system engineers building distributed information systems. Distributed applications are a necessity in most central application sectors of the contemporary computerized society, for instance, in office automation, banking, manufacturing, telecommunication and transportation. This book focuses on the techniques available or under development, with the goal of easing the burden of constructing reliable and maintainable interoperable information systems. The topics covered in this book include: Management of distributed systems; Frameworks and construction tools; Open architectures and interoperability techniques; Experience with platforms like CORBA and RMI; Language interoperability (e.g. Java); Agents and mobility; Quality of service and fault tolerance; Workflow and object modelling issues; and Electronic commerce . The book contains the proceedings of the International Working Conference on Distributed Applications and Interoperable Systems II (DAIS'99), which was held June 28-July 1, 1999 in Helsinki, Finland. It was sponsored by the International Federation of Information Processing (IFIP). The conference program presents the state of the art in research concerning distributed and interoperable systems. This is a topical research area where much activity is currently in progress. Interesting new aspects and innovative contributions are still arising regularly. The DAIS series of conferences is one of the main international forums where these important findings are reported.

Design of Very High-Frequency Multirate Switched-Capacitor Circuits presents the theory and the corresponding CMOS implementation of the novel multirate sampled-data analog interpolation technique which has its great potential on very high-frequency analog frond-end filtering due to its inherent dual advantage of reducing the speed of data-converters and DSP core together with the specification relaxation of the post continuous-time filtering. This technique completely eliminates the traditional phenomenon of sampled-and-hold frequency-shaping at the lower input sampling rate. Also, in order to tackle physical IC imperfections at very high frequency, the state-of-the-art circuit design and layout techniques for high-speed Switched-Capacitor (SC) circuits are comprehensively discussed:

-Optimum circuit architecture tradeoff analysis
-Simple speed and power trade-off analysis of active elements
-High-order filtering response accuracy with respect to capacitor-ratio mismatches
-Time-interleaved effect with respect to gain and offset mismatch
-Time-interleaved effect with respect to timing-skew and random jitter with non-uniformly holding
-Stage noise analysis and allocation scheme
-Substrate and supply noise reduction
-Gain-and offset-compensation techniques
-High-bandwidth low-power amplifier design and layout
-Very low timing-skew multiphase generation

Two tailor-made optimum design examples in CMOS are presented. The first one achieves a 3-stage 8-fold SC interpolating filter with 5.5MHz bandwidth and 108MHz output sampling rate for a NTSC/PAL CCIR 601 digital video at 3 V. Another is a 15-tap 57MHz SC FIR bandpass interpolating filter with 4-fold sampling rate increase to 320MHz and the first-time embedded frequency band up-translation for DDFS system at 2.5V. The corresponding chip prototype achieves so far the highest operating frequency, highest filter order and highest center frequency with highest dynamic range under the lowest supply voltage when compared to the previously reported high-frequency SC filters in CMOS.

E-government has become a global phenomenon through its use of Internet technologies as a platform for exchanging information, providing services, and transacting with citizens, businesses, and other arms of government. E-Government Development and Diffusion: Inhibitors and Facilitators of Digital Democracy provides a comprehensive, integrative, and global assessment of the e-government evolution in terms of real-life success and failure cases. Containing research from leading international experts, this Premier Reference Source presents concepts from contemporary and diverse perspectives within the field.

It is with great pleasure that I present this fourth vol ume in the series "Advanced Applications in Pattern Recognition." It would be difficult to find two authors better versed in the design and application of parallel image processing systems, due to both their own many years of pioneering in the field and their encyclopedic knowledge of what is going on in uni versity and industrial laboratories around the world. The monograph is unique in its parallel presentation of orthogonal and hexagonal dissections, and the wealth of graphic illustration of algorithmic procedures for processing and analyz ing images in the various known implementations of parallel im age-processing architectures. This volume should find a place on the bookshelf of every practitioner of pattern recognition, image processing, and compu ter graphics. Morton Nadler General Editor vii PREFACE This book endeavors to introduce the reader to the subject of cellular logic and cellular automata and is devoted particu larly to those parts dealing with the manipulation of pictorial data. The study of cellular automata owes much to the pioneer ing work of John von Neumann during the 1950s. Von Neumann was interested in general problems in the behavior of computing structures and was immensely impressed by the complexity and performance of the human brain, which he felt must point to wards successful designs for automatic computing machines."

This book, about a newly emerging area of research in instructional technology, has as its title the acronym "CSCL." Initially, CSCL was chosen as an acronym for Computer-Supported Collaborative Learning. However, some would argue that "collaborative" is often not a descriptive term for what learners do in instructional settings; further, as the field develops, the technology used to support collaboration may not always involve computers, at least not in the direct ways they have been used to support instruction in the past. To avoid getting bogged down in this terminological debate, this book uses CSCL as a designation in its own right, leaving open to interpretation precisely what words it stands for.
The authors talk a great deal about the theory underlying their work. In part, this is because that is what they were asked to do, but it is also an indication of the state of the field. In an established paradigm in which the theories and methods are well agreed upon, such discussion is less central. CSCL, however, has not yet reached the stage of "normal" science. There is much to be worked out yet. This book is offered with the hope that it will help to define a direction for future work in this field.
The chapters appear in alphabetical order (except for the introductory chapter and the afterword) -- not for lack of a better way to organize the chapters, but rather because the organizational possibilities are too numerous and this order does not privilege one over another. By not imposing a topical organizing structure on this collection, it is hoped that readers will feel freer to explore the chapters in a way that best suits their needs.
COPY FOR BIND-CARD CD-ROM info ................................. There is an accompanying CD-Rom for this proceedings that will become available September 1998. Purchasers of the proceedings may obtain a copy of this CD-ROM at no cost by contacting Lawrence Erlbaum Associates, Inc. phone: (201) 236-9500 toll-free: 1-800-9-BOOKS-9 (1-800-926-6579) 9am-5pm EST fax: (201) 236-0072 e-mail: [email protected] Web site: www.erlbaum.com address: 10 Industrial Avenue, Mahwah, NJ 07430-2262
The CD-ROM was funded through a grant from the National Science Foundation.

The articles in this proceedings were presented at the 13th International Conference of the Chilean Computer Science Society held in La Serena, Chile on October 14-16, 1993. A record number of 90 submissions were received this year in response to the call for papers. They came from 19 countries in four continents. The 44 articles presented here were selected by the program committee whose members were Ricardo Baeza-Yates (Chair, Univ. de Chile) Leopoldo Bertossi (U niv. Catolica de Chile) Jorge Boria (Schlumberger, USA & UNICEN, Argentina) Edgardo Broner (Univ. Simon Bolivar, Venezuela) Pere Brunet (Polytechnic of Catalunya, Spain) Jose Blakeley (Texas Instruments, USA) Eduardo Krell (Fundacion Chile) Tomas Lang (Univ. of California at Irvine, USA) Rosana Lanzelotte (PUC-Rio, Brazil) Stefano Levialdi (Univ. di Roma, Italy) Jorge Lobo (Univ. of Illinois at Chicago, USA) Jose Palazzo (UFRGS, Brazil) Christian Queinnec (Poly technique & INRIA, France) Gregory Rawlins (Indiana University, USA) Carlos Scheel (Tecnologico de Monterrey, Mexico) Robbert Van Renesse (Cornell Univ. , USA) The criteria for selection was based primarily on quality; we also considered relevance, clarity and the potential benefit to the community. The contents of these proceedings are organized on six main areas (number of papers in parentheses) : Algorithms and Data Structures (10); Databases and Information Systems (6); Distributed Systems and Computer Architecture (6); Logic and Knowledge (8); Petri Nets (4); and Software Engineering and Programming Languages (10). They also include one invited paper.

In this newly revised book On Sonic Art, Trevor Wishart takes a wide-ranging look at the new developments in music-making and musical aesthetics made possible by the advent of the computer and digital information processing. His emphasis is on musical rather than technical matters. Beginning with a critical analysis of the assumptions underlying the Western musical tradition and the traditional acoustic theories of Pythagoras and Helmholtz, he goes on to look in detail at such topics as the musical organization of complex sound-objects, using and manipulating representational sounds and the various dimensions of human and non-human utterance. In so doing, he seeks to learn lessons from areas (poetry and sound-poetry, film, sound effects and animal communication) not traditionally associated with the field of music.
About the Author
Trevor Wishart is a composer, living and working in the North of England. His musical works cover a wide range, from environmental music events staged in spe

Interleaving Planning and Execution for Autonomous Robots develops a formal representation for interleaving planning and execution in the context of incomplete information. This work bridges the gap between theory and practice in robotics by presenting control architectures that are provably sound, complete and optimal, and then describing real-world implementations of these robot architectures. Dervish, winner of the 1994 AAAI National Robot Contest, is one of the robots featured. Interleaving Planning and Execution for Autonomous Robots is based on the author's PhD research, covering the same material taught in CS 224, the very popular Introduction to Robot Programming Laboratory taught at Stanford for four years by Professor Michael Genesereth and the author.

This is a thorough description of this increasingly important technology, starting from the development of head-up displays (HUDs), particularly specifications and standards and operational problems associated with HUD use. HUD involvement in spatial disorientation and its use in recognizing and recovering from unusual attitudes is discussed. The book summarizes the design criteria including hardware, software, interface and display criteria. It goes on to outline flight tasks to be used for evaluating HUDs and discusses the impact of HUDs on flight training. Recent work indicates that a HUD may allow a significant reduction in the time required to train a pilot on a particular aircraft, even considering non-HUD-related tasks. The author concludes with a review of unresolved HUD issues and recommendations for further research and provides an impressive bibliography, glossary and index. Within the military aviation sector the book will be of use to industry, research agencies, test pilot schools and air force training establishments. In the civil area regulatory authorities, airlines and industry will also have an increasing interest.

This monograph describes new methods for intelligent pattern recognition using soft computing techniques including neural networks, fuzzy logic, and genetic algorithms. Hybrid intelligent systems that combine several soft computing techniques are needed due to the complexity of pattern recognition problems. Hybrid intelligent systems can have different architectures, which have an impact on the efficiency and accuracy of pattern recognition systems, to achieve the ultimate goal of pattern recognition. This book also shows results of the application of hybrid intelligent systems to real-world problems of face, fingerprint, and voice recognition. This monograph is intended to be a major reference for scientists and engineers applying new computational and mathematical tools to intelligent pattern recognition and can be also used as a textbook for graduate courses in soft computing, intelligent pattern recognition, computer vision, or applied artificial intelligence.

Geographic information system (GIS) computer technology is revolutionizing the way we interact with information. Data, text, drawings, maps, and images contain information that can be accessed and used intuitively through drawings containing graphical representations of the facilities to which they apply, e.g., emission stacks, sampling locations, and sites, to name only a few examples.
Environmental GIS technology is being applied with increasing frequency to manage industrial facilities. Environmental GIS describes the application of this information technology. It addresses environmental, safety, and health (ES&H) information management in an integrated manner. The book focuses on dealing with information from an organizational or corporate standpoint, meaning that the needs are not specialized to the ES&H area, but are an inherent part of managing the organization. Environmental, safety, and health information management needs are examined in the context of the overall corporate information flow. This book addresses

This book presents the fundamental concepts of fuzzy logic and fuzzy control, chaos theory and chaos control. It also provides a definition of chaos on the metric space of fuzzy sets. The book raises many questions and generates a great potential to attract more attention to combine fuzzy systems with chaos theory. In this way it contains important seeds for future scientific research and engineering applications.

One of the main applications of VHDL is the synthesis of electronic circuits. Circuit Synthesis with VHDL is an introduction to the use of VHDL logic (RTL) synthesis tools in circuit design. The modeling styles proposed are independent of specific market tools and focus on constructs widely recognized as synthesizable by synthesis tools. A statement of the prerequisites for synthesis is followed by a short introduction to the VHDL concepts used in synthesis. Circuit Synthesis with VHDL presents two possible approaches to synthesis: the first starts with VHDL features and derives hardware counterparts; the second starts from a given hardware component and derives several description styles. The book also describes how to introduce the synthesis design cycle into existing design methodologies and the standard synthesis environment. Circuit Synthesis with VHDL concludes with a case study providing a realistic example of the design flow from behavioral description down to the synthesized level. Circuit Synthesis with VHDL is essential reading for all students, researchers, design engineers and managers working with VHDL in a synthesis environment.

As increasing numbers of social anthropoloists use computers for wordprocessing, interest in other applications inevitably follows. "Applications in Computing for Social Anthropologists" addresses this interest and encourages researchers to make full use of their computers to help them organize data. Firstly, the author discusses computing applications in relation to research activities shared by all anthropologists - ethnographic fieldwork, management and analysis of footnotes and the use of visual and aural material. The book then illustrates the way in which computer-based representations can satisfy the requirements of anthropological methods with a detailed examination of representing kinship relations in an original way. Nal developments in the representation of visual and aural data on computers, as well as possible applications of knowledge based models are also introduced.

The aim of this volume of scientific essays is twofold. On the one hand, by remembering the scientific figure of Eduardo R. Caianiello, it aims at focusing on his outstanding contributions - from theoretical physics to cybernetics - which after so many years still represent occasion of innovative paths to be fruitfully followed. It must be stressed the contribution that his interdisciplinary methodology can still be of great help in affording and solving present day complex problems. On the other hand, it aims at pinpointing with the help of the scientists contributing to the volume - some crucial problems in present day research in the fields of interest of Eduardo Caianiello and which are still among the main lines of investigation of some of the Institutes founded by Eduardo (Istituto di Cibernetica del CNR, IIAS, etc).

This book has a rather strange history. It began in spring 1989, thirteen years after our Systems Science Department at SUNY-Binghamton was established, when I was asked by a group of students in our doctoral program to have a meeting with them. The spokesman of the group, Cliff Joslyn, opened our meeting by stating its purpose. I can closely paraphrase what he said: "We called this meeting to discuss with you, as Chairman of the Department, a fundamental problem with our systems science curriculum. In general, we consider it a good curriculum: we learn a lot of concepts, principles, and methodological tools, mathematical, computational, heu ristic, which are fundamental to understanding and dealing with systems. And, yet, we learn virtually nothing about systems science itself. What is systems science? What are its historical roots? What are its aims? Where does it stand and where is it likely to go? These are pressing questions to us. After all, aren't we supposed to carry the systems science flag after we graduate from this program? We feel that a broad introductory course to systems science is urgently needed in the curriculum. Do you agree with this assessment?" The answer was obvious and, yet, not easy to give: "I agree, of course, but I do not see how the situation could be alleviated in the foreseeable future."

Techniques for Designing and Analyzing Algorithms Design and analysis of algorithms can be a difficult subject for students due to its sometimes-abstract nature and its use of a wide variety of mathematical tools. Here the author, an experienced and successful textbook writer, makes the subject as straightforward as possible in an up-to-date textbook incorporating various new developments appropriate for an introductory course. This text presents the main techniques of algorithm design, namely, divide-and-conquer algorithms, greedy algorithms, dynamic programming algorithms, and backtracking. Graph algorithms are studied in detail, and a careful treatment of the theory of NP-completeness is presented. In addition, the text includes useful introductory material on mathematical background including order notation, algorithm analysis and reductions, and basic data structures. This will serve as a useful review and reference for students who have covered this material in a previous course. Features The first three chapters provide a mathematical review, basic algorithm analysis, and data structures Detailed pseudocode descriptions of the algorithms along with illustrative algorithms are included Proofs of correctness of algorithms are included when appropriate The book presents a suitable amount of mathematical rigor After reading and understanding the material in this book, students will be able to apply the basic design principles to various real-world problems that they may encounter in their future professional careers.

Written by a distinguished cast of contributors, Alan Turing: Life and Legacy of a Great Thinker is the definitive collection of essays in commemoration of the 90th birthday of Alan Turing. This fascinating text covers the rich facets of his life, thoughts, and legacy, but also sheds some light on the future of computing science with a chapter contributed by visionary Ray Kurzweil, winner of the 1999 National Medal of Technology. Further, important contributions come from the philosopher Daniel Dennett, the Turing biographer Andrew Hodges, and from the distinguished logician Martin Davis, who provides a first critical essay on an emerging and controversial field termed "hypercomputation."

This accessible, practical guide includes everything you need to know to capture fantastic photographs of birds on your doorstep. In RSPB How to Photograph Garden Birds, celebrated photographer and wildlife writer Mark Carwardine shares his expert advice and insider tips and tricks for capturing the perfect photo. Whether you have a professional camera and a garden filled with birds, or a smartphone and access to a bird table, his guidance will improve your photography in leaps and bounds. Packed with beautiful photographs, this book is a step-by-step masterclass on garden bird photography - from attracting different species to using artificial rain and capturing spectacular images of birds in flight. Once you've mastered the basics, you can make garden bird photography as simple or as challenging as you like. A robin perched on a garden spade? Easy. A blackbird feeding among fallen leaves? No problem. A blue tit in flight? Might take some planning but still very achievable. And there's more. Garden bird photography isn't only rewarding in its own right - it's also a sensational way to hone wildlife photography and field skills that you can then adapt to suit any subject anywhere in the world.