This book discusses inverse problems that arise in the estimation and control of distributed parameter systems in the face of uncertainty, as well as applications of these techniques to mathematical modelling for problems of applied system analysis (eg environmental issues, technological issues, technological processes, biomethematical models, mathematical economy and other fields). The main topics of the research papers which comprise this book are: estimation of the state and of the parameters for distributed parameter systems, control problems with state constraints, exponential stabilization and shape optimization. This book of proceedings on control theory, applied system analysis and estimation theory is intended for researchers, advanced students and engineers.

Formal methods enable computer architecture and software design to be mathematically proved correct before they are implemented. The complexity and time-consuming nature of such proofs have limited the applications of formal methods in the main to defence and safety-critical applications. The mural project (a joint Alvey-funded project between "M"anchester "U"niversity and "R"utherford "A"ppleton "L"aboratories) has developed a software support system to help the user of formal methods. mural has created a user-friendly software environment (with extensive use of windows) that makes best use of human talents to produce computer systems that are proved to be correctly designed. Professor Cliff Jones is internationally known as the developer of the VDM system of formal notation (Vienna Development Method). This book describes the requirements, concepts, and realisation of the mural system. The authors present systematically and completely the results of this substantial research project, from the basic theoretical level to its effective implementation. The book will be of equal interest to academics working on formal methods at research level (and perhaps to graduate research students), and to practitioners and software engineers who are using - or who will have to use for defence contracts, etc. - formal methods.

CAiSE '91, held at the Norwegian Institute of Technology in May 1991, is the third in a series of conferences on advanced information systems engineering. The call for papers for CAiSE '91 was given a wide international distribution. The programme committee was chosen from very well reputed researchers in the international information systems engineering community, as well as key professionals in European industrial and consultant companies. The number and quality of papers submitted was very satisfactory, and 29 papers were selected for publication in this volume.

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 1989 Workshop on the Assessment of Formal Methods for Trustworthy Com puter Systems (FM89} was an invitational workshop that brought together repre sentatives from the research, commercial and governmental spheres of Canada, the United Kingdom, and the United States. The workshop was held in Halifax, Nova Scotia, Canada, from July 23 through July 27, 1989. This document reports the activities, observations, recommendations and conclusions resulting. from FM89. 1. 1 Purpose of Workshop The primary purpose for holding FM89 was to assess the role of formal methods in the development and fielding of trustworthy critical systems. The need for this assessment was predicated upon four observations: 1. Critical systems are increasingly being controlled by computer systems; 2. Existing techniques for developing, assuring and certifying computer-based critical systems are inadequate; 3. Formal methods have the potential for playing the same role in the devel opment of computer-based systems as applied mathematics does for other engineering disciplines; and 4. Formal methods have had limited impact on the development of comput- based systems and supporting technologies. . The goal of the workshop was to complete the following tasks: 1. Assess the problems retarding the development of trustworthy critical systems; 2. Determine the (potential) impact of applying formal methods techniques to the development of trustworthy critical systems; 3. Determine the research and development required to facilitate a broader ap plication of formal methods techniques; 4."

The Nordic Conference on Advanced Information Systems Engineering (CAiSE) is an annual international conference for users, developers and researchers of information systems technology and methodology. A distinctive characteristic of the CAiSE conference series is the objective to appeal to advanced practitioners as well as to researchers, and to promote communication between the two groups. In this second CAiSE conference, the program was divided into two types of sessions that were not run in parallel: Technical Paper sessions, with formally reviewed technical papers, and Practice and Experience sessions, with invited speakers and panel discussions. The proceedings include the formally reviewed technical papers and abstracts of the invited presentations. The technical papers present important international (mainly European) work in Information Systems Engineering within such areas as conceptual modelling, prototyping, requirements engineering, design support, software process modelling, tool design, and tool experiences. The abstracts of invited speakers' presentations give an indication of current best industrial practice.

Current research into formal methods for hardware design is presented in the papers in this volume. Because of the complexity of VLSI circuits, assuring design validity before circuits are manufactured is imperative. The goal of research in this area is to develop methods of improving the design process and the quality of the resulting designs. The major trend apparent at the workshop is that researchers are rapidly moving away from post hoc proof techniques with their great expense. A number of papers were presented that dealt with problems of synthesizing correct circuits and of designing with the goal of verification. Researchers are also beginning to deal with the theoretical issues of reasoning about concurrent systems and asynchronous systems, and to introduce new logical tools such as constructive type theory and category theory. Most of the research reported was performed in the United States.

The growing importance of the systems for symbolic computation has greatly influenced the decision of organizing DISCO '90 which is short for International Symposium on Design and Implementation of Symbolic Computation Systems. DISCO '90 focuses mainly on the most innovative methodological and technological aspects of hardware and software system design and implementation for Symbolic and Algebraic Computation, Automated Reasoning, Software Environments (Languages and User Interfaces), and Automatic Programming. In particular, it includes papers on the design and the development of significant running systems. The general objective of DISCO '90 is to present an up-to-date view of the field, while encouraging the scientific exchange among academic, industrial and user communities of the development of systems for symbolic computation.

This volume contains the proceedings of a workshop held in Grenoble in June 1989. This was the first workshop entirely devoted to the verification of finite state systems. The workshop brought together researchers and practitioners interested in the development and use of methods, tools and theories for automatic verification of finite state systems. The goal at the workshop was to compare verification methods and tools to assist the applications designer. The papers in this volume review verification techniques for finite state systems and evaluate their relative advantages. The techniques considered cover various specification formalisms such as process algebras, automata and logics. Most of the papers focus on exploitation of existing results in three application areas: hardware design, communication protocols and real-time systems.

This research monograph gives a complete discussion of the theory of the discrete-time hyperbolic map. Both scalar and matrix representations are considered. The dynamics of the map are analyzed and discussions of stability, quasiperiodicity, and chaos are included. Several applications are discusssed, the most important being the discrete-time linear time-invariant quadratic regulator. The results obtained from this analysis are then extended to the continuous-time linear regulator. A discussion of the linear quadratic regulator with negative state weighting provides some important insights into the general regulator theory. The results contained in this monograph should be accessible to the first year graduate student or advanced senior undergraduate. Interested readers should also have a background in ODE's, difference equations, optimization theory, and/or digital control theory.

Computer simulation has developed into a powerful tool for problem solving in a variety of areas, in the sciences as well as in industrial environments. New developments such as parallel simulation techniques will further improve the efficiency of the tool. Decision support systems, either based on mathematical models or on knowledge based expert systems will make computer simulation accessible to more users, and will provide better environments for systems analysis, modeling and simulation. Systems Analysis and Simulation presents the papers accepted for the 3rd International Symposium for Systems Analysis and Simulation held in Berlin (GDR) in September of 1988. The contributions selected for this two-volume set present the state of the art and current trends in computer simulation. Volume I emphasizes the theoretical foundations and the methodology for computer simulation and systems analysis. Volume II presents a variety of applications in fields such as manufacturing, robotics, economics, and biology.

The 4th Bad Honnef Conference on Stochastic Differential Systems highlighted recent advances in the areas of stochastic control and filtering theory as well as stochastic analysis. Special emphasis was put on the use of adaptive methods in stochastic systems analysis and on the theory of random fields, both very active fields of current research. There were six survey lectures, two of them on adaptive control of linear stochastic systems (Kumar, Lai), two on problems in stochastic analysis and random fields, (Surgailis, Wong) and one on singular perturbations in nonlinear filtering (Bensoussan). In addition, 37 research papers pertaining to the main topics of the conference were presented.

Dieses Buch enthalt die Beitrage der 4. GI/ITG/GMA-Fachtagung uber Fehlertolerierende Rechensysteme, die im September 1989 in einer Reihe von Tagungen in Munchen 1982, Bonn 1984 sowie Bremerhaven 1987 veranstaltet wurde. Die 31 Beitrage, darunter 4 eingeladene, sind teils in deutscher, uberwiegend aber in englischer Sprache verfasst. Insgesamt wird durch diese Beitrage die Entwicklung der Konzeption und Implementierung fehlertoleranter Systeme in den letzten zwei Jahren vor allem in Europa dokumentiert. Samtliche Beitrage berichten uber neue Forschungs- oder Entwicklungsergebnisse.

This volume contains the papers which were presented at the second workshop "Computer Science Logic" held in Duisburg, FRG, October 3-7, 1988. These proceedings cover a wide range of topics both from theoretical and applied areas of computer science. More specifically, the papers deal with problems arising at the border of logic and computer science: e.g. in complexity, data base theory, logic programming, artificial intelligence, and concurrency. The volume should be of interest to all logicians and computer scientists working in the above fields.

The field of modern mathematical system theory has its origins in the work of R.E. Kalman in the late fifties. It came to a rapid development in the early sixties, and has seen a continuing and still growing stream of contributions in the years that followed. Today, it stands as a well-established discipline. The volume Three Decades of Mathematical System Theory surveys the developments in this field by presenting 21 articles covering the broad area of system and control theory. All articles have been written by well-known authors, who were invited to give their personal expert view on a particular direction of research. Together, the contributions in this volume review the wide range of mathematical methods that are being applied in modern system and control theory. The mathematical fields that are involved included differential and algebraic geometry, linear and commutative algebra, and functional and stochastic analysis.

Computer aided systems theory is urgently needed for the design of software for CAD. New generation workstations together with the methods and tools of artificial intelligence allow the implementation of the powerful user-driven interactive systems required for CAST. Implementation of CAST software requires a sound meth- odology from systems theory, user functions tailored to specific applications, and a man-machine interface designed using latest results from cognition research and AI. Most of the papers in this volume are based on talks delivered at EUROCAST '89 held in the Canary Islands in February/March 1989.

This volume contains selected papers for the Parcella '88, the Fourth International Workshop on "Parallel Processing by Cellular Automata and Arrays" held in Berlin from October 17 to 21, 1988. The profile of the Parcella workshop series is focused on problems of processing by regular structures, i.e. their "flexibilization" or adapting to "irregular" algorithms and, closely related to this, on the "regularization" of algorithms for their embedding into regular structures. It seems that these problems will have an increasing priority within the list of central problems in parallelization and will determine the profile of Parcella for the next years.

This "Lecture Notes" volume is based on the "International Workshop on High Performance Transaction Systems" held in the Asilomar Conference Center, September 28-30, 1987. Many of the problems identified during the workshop are liable to determine the future development of transaction systems and distributed high performance systems in general for many years to come. So the organizers of HPTS '87 felt encouraged to collect the papers presented at the workshop in order to make them accessible to a wider audience of interested developers and researchers. Since some of the contributions represented work in progress, the authors agreed to prepare revised and updated versions of their papers for this publication. This accounts for the long delay between the event itself and the publication, but on the other hand it provides the reader with a state-of-the-art account of transaction processing topics. The book is organized according to the major sections of the workshop. In the network section the reader finds an analysis of two of the major "paradigms" in networking, ISO/OSI and SNA, from the perspective of transaction processing. In the next section four different transaction processing and database systems are described: Model 204 - a database management system marketed by Computer Corporation of America, Tandem's NonStop SQL, Citicorp's transaction processing system and ALCS, which basically is a version of TPF running under MVS/XA. The section on architectural issues contains four very different contributions which are fairly representative of the type of problems in transaction systems investigated in the research community. Finally, performance evaluations and system comparisons are presented.

TAPSOFT '89 is the Third International Joint Conference on Theory and Practice of Software Development held in Barcelona, Spain, March 13-17, 1989. The conference consisted of three parts: - Advanced Seminar on Foundations of Innovative Software Development - Colloquium on Trees in Algebra and Programming (CAAP '89) - Colloquium on Current Issues in Programming Languages (CCIPL) The TAPSOFT '89 Conference Proceedings are published in two volumes. The first volume includes the papers from CAAP plus the more theoretical ones of the invited papers. The second volume comprises the papers from CCIPL and the invited papers more relevant to current issues in programming languages.

TAPSOFT '89 is the Third International Joint Conference on Theory and Practice of Software Development held in Barcelona, Spain, March 13-17, 1989. The conference consissted of three parts: - Advanced Seminar on Foundations of Innovative Software Development - Colloquium on Trees in Algebra and Programming (CAAP '89) - Colloquium on Current Issues in Programming Languages (CCIPL) The TAPSOFT '89 Conference Proceedings are published in two volumes. The first volume includes the papers from CAAP plus the more theoretical ones of the invited papers. The second volume comprises the papers from CCIPL and the invited papers more relevant to current issues in programming languages.

The aim of the workshop was to discuss whether research on implementation of programming languages and research on logic programming can mutually benefit from each others results. The intention was to bring together researchers from both fields, especially those working in the area of their intersection. Problems such as formal specification of compilers and syntax-based editors, program analysis and program optimization have been traditionally studied by implementors of algorithmic languages and have resulted in a number of well-established notions, formalisms and techniques. At the same time, an increasing number of people use logic programming as a way of specifying compilers or other programming environment tools, taking advantage of the relatively high level of logic programming and the growing efficiency of Prolog implementations. On the other hand, research on logic programming raises the questions of analysis of logic programs and their optimization. These are motivated primarily by compiler construction for logic programs, by studies on the methodology of logic programming and by the attempts to amalgamate logic programming and functional programming. The purpose of the workshop is to review the techniques developed in one (or both) of the fields which could also be of some help in the other one and to facilitate the transfer of expertise. It seems important to compare notions used in both fields: showing similarities between them may prevent rediscovering results already known, while studying differences may contribute to the transfer of technology.

This volume presents the proceedings of the 14th International Workshop on Graph-Theoretic Concepts in Computer Science (WG '88), held from June 15 to 17, 1988 in Amsterdam, The Netherlands. It contains 31 papers on new or current developments in the area of graph-based algorithms. The topics covered include e.g. structural graph theory, parallel graph algorithms, graph-based modeling (in database theory and VLSI), computational geometry and applied graph theory. The book contains the revised versions of all the papers presented at the workshop. The revisions are based on comments and suggestions received by the authors during and after the workshop.

This volume contains the proceedings of the 8th Conference on Foundations of Software Technology and Theoretical Computer Science held in Pune, India, on December 21-23, 1988. This internationally well-established Indian conference series provides a forum for actively investigating the interface between theory and practice of Software Science. It also gives an annual occasion for interaction between active research communities in India and abroad. Besides attractive invited papers the volume contains carefully reviewed submitted papers on the following topics: Automata and Formal Languages, Graph Algorithms and Geometric Algorithms, Distributed Computing, Parallel Algorithms, Database Theory, Logic Programming, Programming Methodology, Theory of Algorithms, Semantics and Complexity.

This volume contains the proceedings of CONCURRENCY 88, an international conference on formal methods for distributed systems, held October 18-19, 1988 in Hamburg. CONCURRENCY 88 responded to great interest in the field of formal methods as a means of mastering the complexity of distributed systems. In addition, the impulse was determined by the fact that the various methodological approaches, such as constructive or property oriented methods, have not had an extensive comparative analysis nor have they been investigated with respect to their possible integration and their practical implications. The following topics were addressed: Specification Languages, Models for Distributed Systems, Verification and Validation, Knowledge Based Protocol Modeling, Fault Tolerance, Distributed Databases. The volume contains 12 invited papers and 14 contributions selected by the program committee. They were presented by authors from Austria, the Federal Republic of Germany, France, Israel, Italy, the Netherlands, the United Kingdom and the United States.

This volume contains the papers which were presented to the workshop "Computer-Science Logic" held in Karlsruhe on October 12-16, 1987. Traditionally Logic, or more specifically, Mathematical Logic splits into several subareas: Set Theory, Proof Theory, Recursion Theory, and Model Theory. In addition there is what sometimes is called Philosophical Logic which deals with topics like nonclassical logics and which for historical reasons has been developed mainly at philosphical departments rather than at mathematics institutions. Today Computer Science challenges Logic in a new way. The theoretical analysis of problems in Computer Science for intrinsic reasons has pointed back to Logic. A broad class of questions became visible which is of a basically logical nature. These questions are often related to some of the traditional disciplines of Logic but normally without being covered adequately by any of them. The novel and unifying aspect of this new branch of Logic is the algorithmic point of view which is based on experiences people had with computers. The aim of the "Computer-Science Logic" workshop and of this volume is to represent the richness of research activities in this field in the German-speaking countries and to point to their underlying general logical principles.