Technological advances are revolutionizing computers and networks to supportdigital video and audio, leading to new design spaces in computer systems and applications. Under the surface of exciting multimedia technologies liesa mine of research problems. This volume presents the proceedings of an international workshop which brought together the leading researchers in allaspects of multimedia computing, communication, storage, and applications. The field of multimedia has witnessed an explosive growth in the last few years and the selection of papers for this workshop was extremely competitive. The volume contains 26 full papers and 14 short papers selected from 128 contributions, organized into parts on: network and operating system support for multimedia; multimedia on-demand services; media synchronization; distributed multimedia systems; network andoperating system support for multimedia; multimedia models, frameworks, and document architectures; and multimedia workstations and platforms.

The main aims of the series of volumes "Advances in Petri Nets" are: - to present to the "outside" scientific community a fair picture of recent advances in the area of Petri nets, and - to encourage those interested in the applications and the theory of concurrent systems to take a closer look at Petri nets and then join the group of researchers working in this fascinating and challenging area. This volume is based on the proceedings of the 12th International Conference on Applications and Theory of Petri Nets, held in Gjern, Denmark, in June 1991. It contains 18 selected and revised papers covering all aspects of recent Petri net research.

This volume presents the proceedings of the fifth Conference on Advanced Information Systems Engineering, CAiSE '93, held at the University of Paris-Sorbonne in June 1993. Initiated by J. Bubenko from the Swedish Institute for Systems Development in Stockhom, Sweden, and A. Solvberg from the Norwegian Institute of Technology in Trondheim, Norway, this series of conferences evolved from a Nordic audience to a truly European one. All the conferences have attracted international papers of high quality, indicating the needfor an international conference on advanced information systems engineering topics. The spectrum of contributions contained in the present proceedings extends from inevitable and still controversial issues regarding modeling of information systems, via development environments and experiences, to various novel views forsome specific aspects of information systems development such as reuse, schema integration, and evolution.

Enterprise operation efficiency is seriously constrained by the inability to provide the right information, in the right place, at the right time. In spite of significant advances in technology it is still difficult to access information used or produced by different applications due to the hardware and software incompatibilities of manufacturing and information processing equipment. But it is this information and operational knowledge which makes up most of the business value of the enterprise and which enables it to compete in the marketplace. Therefore, sufficient and timely information access is a prerequisite for its efficient use in the operation of enterprises. It is the aim of the ESPRIT project AMICE to make this knowledge base available enterprise-wide. During several ESPRIT contracts the project has developed and validated CIMOSA: Open System Architecture for CIM. The CIMOSA concepts provide operation structuring based on cooperating processes. Enterprise operations are represented in terms of functionality and dynamic behaviour (control flow). Information needed and produced, as well as resources and organisational aspects relevant in the course of the operation are modelled in the process model. However, the different aspects may be viewed separately for additional structuring and detailing during the enterprise engineering process.

This volume gives the proceedings of the Fourth Workshop on Computer-Aided Verification (CAV '92), held in Montreal, June 29 - July 1, 1992. The objective of this series of workshops is to bring together researchers and practitioners interested in the development and use of methods, tools and theories for the computer-aided verification of concurrent systems. The workshops provide an opportunity for comparing various verification methods and practical tools that can be used to assist the applications designer. Emphasis is placed on new research results and the application of existing results to real verification problems. The volume contains 31 papers selected from 75 submissions. These are organized into parts on reduction techniques, proof checking, symbolic verification, timing verification, partial-order approaches, case studies, model and proof checking, and other approaches. The volume starts with an invited lecture by Leslie Lamport entitled "Computer-hindered verification (humans can do it too)."

Writing a compiler is a very good practice for learning how complex problems could be solved using methods from software engineering. It is extremely important to program rather carefully and exactly, because we have to remember that a compiler is a program which has to handle an input that is usually incorrect. Therefore, the compiler itself must be error-free. Referring to Niklaus Wirth, we postulate that the grammatical structure of a language must be reflected in the structure of the compiler. Thus, the complexity of a language determines the complexity of the compiler (cf. Compilerbau. B. G. Teubner Verlag, Stuttgart, 1986). This book is about the translation of programs written in a high level programming language into machine code. It deals with all the major aspects of compilation systems (including a lot of examples and exercises), and was outlined for a one session course on compilers. The book can be used both as a teacher's reference and as a student's text book. In contrast to some other books on that topic, this text is rather concentrated to the point. However, it treats all aspects which are necessary to understand how compilation systems will work. Chapter One gives an introductory survey of compilers. Different types of compilation systems are explained, a general compiler environment is shown, and the principle phases of a compiler are introduced in an informal way to sensitize the reader for the topic of compilers.

About this Book This book is a detailed introduction to programming with the OSF /MotifI'M graphical user interface. It is an introduction in that it does not require the reader to have experience programming in the X Window environment. It is detailed in that it teaches you how to use the interface components provided by Motif in a complex application. Although it contains a great deal of reference material, it is not meant as an authoritative reference - that is the job of the OSF/Motif Programmer's Reference, which uses over 900 pages in the process. Instead, this book provides its reference material in a practical, "how to" manner and allows the reader to use the Programmer's Reference effectively. The target reader is an experienced C programmer and user of the X Window System under the UNIX operating system. 'the reader should be familiar with the tools provided by UNIX for the compilation and testing of programs; while this book does examine the process by which a Motif program is compiled, it does not explain that process. It also assumes that the reader is familiar with "x" terms such as 'pointer' and 'display'.

Code Generation - Concepts, Tools, Techniques is based upon the proceedings of the Dagstuhl workshop on code generation which took place from 20-24 May 1991. The aim of the workshop was to evaluate current methods of code generation and to indicate the main directions which future research is likely to take. It provided an excellent forum for the exchange of ideas and had the added advantage of bringing together European and American experts who were unlikely to meet at less specialised gatherings. This volume contains 14 of the 30 papers presented at the Dagstuhl workshop. The papers deal mainly with the following four topics: tools and techniques for code generation, code generation for parallel architectures, register allocation and phase ordering problems, and formal methods and validations. Most of the papers assess the progress of on-going research work, much of which is published here for the first time, while others provide a review of recently completed projects. The volume also contains summaries of two discussion groups which looked at code generation tools and parallel architectures. As a direct result of one of these discussions, a group of the participants have collaborated to make a pure BURS system available for public distribution. This system, named BURG, is currently being beta-tested. Code Generation - Concepts, Tools, Techniques provides a representative summary of state-of-the-art code generation techniques and an important assessment of possible future innovations. It will be an invaluable reference work for researchers and practitioners in this important area.

The trend towards powerful workstations and high-speed networks has enabled applications to communicate and manipulate digital audio and video. These are continuous media and differ from discrete media such as text and graphics in that they have stringent delay and bandwidth requirements. Neither the mechanisms used to transport ordinary data over networks nor present communication protocols are sufficient to communicate continuous media. Special operating system support must also be provided to meet the requirements of both discrete and continuous media in future multimedia applications. This volume contains the proceedings of the Second International Workshop on Network and Operating System Support for Digital Audio and Video, held in cooperation with ACM SIGCOMM and SIGOPSat the IBM European Networking Center in Heidelberg, Germany, in November 1991. The volume contains 33 selected papers together with summaries of the workshop sessions compiled by the session chairmen.

The main aims of the series of volumes "Advances in Petri Nets" are: - to present to the "outside" scientific community a fair picture of recent advances in the area of Petri nets, and - to encourage those interested in the applications and theory of concurrent systems to take a closer look at Petri nets and then join the group of researchers working in this fascinating and challenging area. The ESPRIT Basic Research Action DEMON (DEsign Methods based On Nets) has been a focus of developments withinthe Petri net community for the last three years. The papers presented in this special volume have been selected from papers submitted by participants in DEMON. The papers have been refereed and appear in revised form. The volume contains technical contributions giving insights into a number of major achievements of the DEMON project. It also contains four survey papers covering important research areas. The volume begins witha description of DEMON given by its coordinator E. Best.

This volume contains the proceedings of the fifth International Workshop on Distributed Algorithms (WDAG '91) held in Delphi, Greece, in October 1991. The workshop provided a forum for researchers and others interested in distributed algorithms, communication networks, and decentralized systems. The aim was to present recent research results, explore directions for future research, and identify common fundamental techniques that serve as building blocks in many distributed algorithms. The volume contains 23 papers selected by the Program Committee from about fifty extended abstracts on the basis of perceived originality and quality and on thematic appropriateness and topical balance. The workshop was organizedby the Computer Technology Institute of Patras University, Greece.

In general, distributed systems can be classified into Distributed File Systems (DFS) and Distributed Operating Systems (DOS). The survey which follows distinguishes be tween DFS approaches in Chapters 2-3, and DOS approaches in Chapters 4-5. Within DFS and DOS, I further distinguish "traditional" and object-oriented approaches. A traditional approach is one where processes are the active components in the systems and where the name space is hierarchically organized. In a centralized environment, UNIX would be a good example of a traditional approach. On the other hand, an object-oriented approach deals with objects in which all information is encapsulated. Some systems of importance do not fit into the DFS/DOS classification. I call these systems "closely related" and put them into Chapter 6. Chapter 7 contains a table of comparison. This table gives a lucid overview summarizing the information provided and allowing for quick access. The last chapter is added for the sake of completeness. It contains very brief descriptions of other related systems. These systems are of minor interest or do not provide transparency at all. Sometimes I had to assign a system to this chapter simply for lack of adequate information about it."

Architectural and hardware advances in computing design are occurring at an ever quickening rate, but it is the operating system that masters the complexity of these new computing devices to make them useful tools. Operating systems can make the difference between an interesting architecture and a useful computing environment. As more complex computational structures and more powerful communication technologies become available, we are faced with the need to develop new generations of operating systems to harness their power. This volume presents the proceedings of an international workshop intended to plot a course for design and development work on operating systems over the coming decade that was held in Dagstuhl Castle, Germany, in July 1991. Eight sessions covered: - Size, scalability and distribution in future operating systems, - The impact of future trends in hardware and communication technology, - Integrating heterogeneous operating systems, - Trends in real-time operating systems, - Fault tolerance support in futute operating systems, - Security and protection support in future operating systems, - The next generation of operating systems, - Supporting mulitmedia applications in distributed systems.

This special volume contains the Proceedings of a Workshop on "Parallel Algorithms and Transputers for Optimization" which was held at the University of Siegen, on November 9, 1990. The purpose of the Workshop was to bring together those doing research on 2.lgorithms for parallel and distributed optimization and those representatives from industry and business who have an increasing demand for computing power and who may be the potential users of nonsequential approaches. In contrast to many other conferences, especially North-American, on parallel processing and supercomputers the main focus of the contributions and discussion was "problem oriented". This view reflects the following philosophy: How can the existing computing infrastructure (PC's, workstations, local area networks) of an institution or a company be used for parallel and/or distributed problem solution in optimization. This volume of the LECfURE NOTES ON ECONOMICS AND MA THEMA TICAL SYSTEMS contains most of the papers presented at the workshop, plus some additional invited papers covering other important topics related to this workshop. The papers appear here grouped according to four general areas. (1) Solution of optimization problems using massive parallel systems (data parallelism). The authors of these papers are: Lootsma; Gehne. (II) Solution of optimization problems using coarse-grained parallel approaches on multiprocessor systems (control parallelism). The authors of these papers are: Bierwirth, Mattfeld, and Stoppler; Schwartz; Boden, Gehne, and Grauer; and Taudes and Netousek.

This volume contains the proceedings of the 4th International Workshop on Distributed Algorithms, held near Bari, Italy, September 24-26, 1990. The workshop was a forum for researchers, students and other interested persons to discuss recent results and trends in the design and analysis of distributed algorithms for communication networks and decentralized systems. The volume includes all 28 papers presented at the workshop, covering current research in such aspects of distributed algorithm design as distributed combinatorial algorithms, distributed algorithms on graphs, distributed algorithms for new types of decentralized systems, distributed data structures, synchronization and load-balancing, distributed algorithms for control and communication, design and verification of network protocols, routing algorithms, fail-safe and fault-tolerant distributed algorithms, distributed database techniques, algorithms for transaction management and replica control, and other related topics.

The market for information technology products is rapidly changing from a manufactur er-driven market where new products were determined by the evolution of technology, to a user-driven market where users buy only products corresponding exactly to their needs and where competition is very strong. Confronted with this market situation, hardware and software producers are being obliged to adopt new strategies, and to make a large number of products available on the market in response to a variety of different needs. As a result of the multiplicity of choice available, the design of an office system which corresponds precisely to user needs is becoming an increasingly complex task. With exactly this in mind, the Commission, as early as 1985, invited submissions of projects aiming at the development of such adequate tools in its Call for Proposals for the ESPRIT Programme, in order to assist companies in the design of their office systems. This topic was recognised as being of strategic importance, considering the low level of penetration of Information Technology in European enterprises compared to the United States and Japan. Following this strategy, the project TODOS was selected and launched. This project has successfully developed tools and methods for the definition of the functional specifi cation of the office system, as well as the system architecture and user interface -results which can be of great interest for the IT community at large.

During the last few years, computers have evolved from pure number crunching machines to "intelligent" problem solving tools. Increasing effort has been spent on the investigation of new approaches and the application of solutions to real world problems. In this way, exciting new techniques have evolved providing support for an increasing number of technical and economical aspects. Applications range from the design and development of ultra highly integrated circuits to totally new man-machine interfaces, from software engineering tools to fault diagnosis systems, from decision support to even the analysis of unemployment. Following a first joint workshop on Advanced Information Processing held in July 1988 at the Institute for Problems of Informatics of the USSR Academy of Sciences (IPIAN) at Moscow, this was the second time that scientists and researchers from the USSR Academy of Sciences and Siemens AG, Corporate Research and Development, exchanged results and discussed recent advances in the field of applied computer sciences. Initiated by Prof. Dr. I. Mizin, Corresponding Member of the USSR Academy of Sciences and Director of IPIAN, and Prof. Dr. H. Schwartzel, Vice President of the Siemens AG and Head of the Applied Computer Science & Software Department, a joint symposium was arranged at the USSR Academy of Sciences in Moscow on June 5th and 6th 1990. The meetings on Information Processing and Software and Systems Design Automation provided a basis both for presentations of ongoing research and for discussions about specific problems.

The purpose of this workshop was to provide a general forum for distributed systems researchers. Special em- phasis was placed on research activities in distributed operating systems and management of distributed sys- stems. This volume includes a selection of the papers presented at the workshop. They focus on the illustration of existing concepts and solutions in distributed systems research and development, exemplified by case study analyses of various projects. The annex contains the position papers prepared for the panel discussions at the workshop.

This book presents the proceedings of the Sixth International Conference on Category Theory and Computer Science, CTCS '95, held in Cambridge, UK in August 1995.The 15 revised full papers included in the volume document the exploitation of links between logic and category theory leading to a solid basis for much of the understanding of the semantics of computation. Notable amongst other advances is the introduction of linear logic and other substructural logics, providing a new approach to proof theory. Further aspects covered are semantics of lambda calculi and type theories, program specification and development, and domain theory.

Die Leistung von Computersystemen ist die ausschlaggebende Groe fur ihren Einsatz. Zur Messung der Leistung wird sehr oft das Benchmark-Verfahren als Standard-Tool eingesetzt, obwohl allgemein bekannt ist, dass die entsprechenden Ergebnisse nur eine sehr beschrankte Aussagekraft haben - dafur spricht naturlich ihre starke Orientierung an der Praxis. Modellbildende Techniken werden haufig zu Recht als "Mathematik-lastig" empfunden und suggerieren zudem eine Genauigkeit jenseits der Realitat. Dabei liegt es auf der Hand, dass beide Standpunkte sich erganzen und zusammen eine wesentlich bessere Messung, Analyse und Bewertung gestatten. Anhand dieser Konzeption erlautert der Autor bessere Methoden zur Leistungsbewertung von Computersystemen.

This volume contains the proceedings of the First International Workshop on Algebraic and Logic Programming held in Gaussig (German Democratic Republic) from November 14 to 18, 1988. The workshop was devoted to Algebraic Programming, in the sense of programming by algebraic specifications and rewrite rule systems, and Logic Programming, in the sense of Horn clause specifications and resolution systems. This includes combined algebraic/logic programming systems, mutual relations and mutual implementation of programming paradigms, completeness and efficiency considerations in both fields, as well as related topics.

This volume is based on the "School/Workshop on Linear Time, Branching Time and Partial Order in Logics and Models for Concurrency" organized by the editors and held in the period May 30-June 3, 1988 at Noordwijkerhout, The Netherlands. The School/Workshop was an activity of the project REX - Research and Education in Concurrent Systems. The volume contains tutorials and research contributions to the three approaches - linear time, - branching time, and - partial order in semantics and proof theory of concurrent programs by the main specialists in this field. It promotes an in-depth understanding of the relative merits and disadvantages of these three approaches. An introduction to the recent literature on the subject is provided by the invited research contributions.

This volume contains the proceedings of an international workshop on "Experiences with Distributed Systems" held September 28-30, 1987, at the University of Kaiserslautern. The workshop was jointly sponsored and organized by the Sonderforschungsbereich 124 "VSLI-Entwurfsmethoden und ParallelitAt" and the European Network Center (ENC) of the IBM Corporation, Heidelberg. The objective of the workshop was to bring together researchers who had gathered substantial experience with the implementation of distributed systems. The emphasis was put on the exchange of (good and bad) experiences with existing concepts in distributed system design rather than presenting new ideas. Participation in the workshop was by invitation only. The presentations can be roughly categorized as reports on a specific project or reports on experiences with a certain topic accumulated through several projects. Other lectures treated general topics such as fault tolerance, design principles for distributed languages and systems, and distributed databases.