The IUTAM Symposium on Three-dimensional Turbulent Boundary Layers was suggested by the Gesellschaft fur Angewandte Mathe- matik (GAMM) and sponsored by the International Union of theor- etical and Applied Mechanics. The symposium was organized by H.H. Fernholz (Hermann-Fottinger-Institut fur Thermo- und Fluiddynamik der Technischen Universitat Berlin) and E. Krause (Aerodynamisches Institut der RWTH Aachen). After two success- ful Euromech Colloquia on the same topic in Berlin 1972 and Trondheim 1975 the organizers felt that another meeting should be convened, this time with participants from inside and out- side Europe. The aim of the symposium has been to bring together scientists who are actively engaged in boundary layer research, both ex- perimental and theoretical. The scope of the meeting encompass- ed incompressible and compressible three-dimensional turbulent boundary layers. Special emphasis was laid on economical cal- culation methods, on measurements of fluctuating quantities and on measuring techniques designed for and applied success- fully to three-dimensional boundary layers. From among thirty-four papers submitted for presentation, twenty- six contributions of twenty-five minutes each were selected by the European mernbers of the Scientific Committee. Furthermore there were four invited lectures of forty-five minutes. Short discussions were held directly after each presentation with a long discussion period at the end of each day. The final dis- cussion on the last day of the symposium was recorded on tape and is presented in a slightly shortened version as the last contribution in this volume.

This volume is a compendium of papers presented during the second TRlennal Symposium on Transportation ANalysis (TRISTAN II) that took place in Capri, Italy on June 23-28, 1994. The Symposium was organized by the Progetto Finalizzato Trasporti and the Istituto di Analisi dei Sistemi ed Informatica of the Italian National Research Council jointly with the Italian Operations Research Society. The purpose of this kind of meetings is to periodically allow an exchange of views and findings by scientists in the field of transportation analysis methods and tools. Therefore, the papers presented dealt with a wide range of topics and cover the different aspects of transportation analysis. The material contained in this book gives particular emphasis to the development of mathematical modelling and algorithms. This development is due to the evolution of digital computers and the continuous increase of the computing power. In fact the need of solving large scale problems (crew scheduling, network traffic control, pollution monitoring and control, . etc ... ) involves in some case, thousands of variables and therefore sophisticated mathematical models and computational algorithms

This volume contains the articles presented at the Fourth InternationallFIP Working Conference on Dependable Computing for Critical Applications held in San Diego, California, on January 4-6, 1994. In keeping with the previous three conferences held in August 1989 at Santa Barbara (USA), in February 1991 at Tucson (USA), and in September 1992 at Mondello (Italy), the conference was concerned with an important basic question: can we rely on computer systems for critical applications? This conference, like its predecessors, addressed various aspects of dependability, a broad term defined as the degree of trust that may justifiably be placed in a system's reliability, availability, safety, security and performance. Because of its broad scope, a main goal was to contribute to a unified understanding and integration of these concepts. The Program Committee selected 21 papers for presentation from a total of 95 submissions at a September meeting in Menlo Park, California. The resulting program represents a broad spectrum of interests, with papers from universities, corporations and government agencies in eight countries. The selection process was greatly facilitated by the diligent work of the program committee members, for which we are most grateful. As a Working Conference, the program was designed to promote the exchange of ideas by extensive discussions. All paper sessions ended with a 30 minute discussion period on the topics covered by the session. In addition, three panel sessions have been organizcd.

This volume is a compendium of papers presented during an Advanced Seminar on Air Traffic Control (ATC) that took place in Capri, Italy on October 28-31, 1991. The Seminar was' organized by the Progetto Finalizzato Trasporti of the Italian National Research Council. The papers presented in the Seminar dealt with a wide range of topics which are currently important in ATC. For example, there were papers on such subjects as recent developments in primary and secondary radar technologies, communications networks and protocols, and the future uses of satellite-based communications, navigation and surveillance in ATC. However, all the papers contained in the volume were selected exclusively from that set of papers that addressed some aspect of the main area of emphasis in the Seminar, namely massive data-processing requirements and computer intensive problems in ATC. Data-processing requirements in A TC have grown enormously over the years. Obviously, the rapid increase in air traffic volumes in most of the world is one of the factors that has contributed to this growth. However, two other developments have contributed much more significantly: first, the ATC system now collects (mostly automatically) immensely more "information per flight" than in the past; and, second, as the system's complexity increases and as it becomes more tightly interconnected geographically, so grows the need to communicate, process and "filter" the data presented to the system's various components."

Ake E.Andersson has always been intellectually on the move. He has selected his own track through the academic system and has formed a school of thought which has brought him international recognition. The cornerstones of his scientific interest are welfare analysis, regional economic dynamics and human capital theory. For his excellent achievements on dynamic analysis in the field of regional economics and regional planning he received the Japanese Honda Prize in 1995. This book provides a sample of the broad ranging research of Ake E.Andersson. Here some of his friends and colleagues have contributed to give various examples from the growing research field "Knowledge and Networks in a Dynamic Economy" in which he has been a great inspiration and in which he has contributed as part of his prodigious output.

The emergence of civil aviation as a means of mass transportation is primarily due to the large scale construction of jet airplanes in the past 30 years or so. A large number of these jet airplanes is currently operating at or beyond their designed fatigue lives. Thus, the structural integrity of these aging airplanes has become an issue of major concern to all nations of the world. To bring the needed technical and research focus on the issues involved in the life-enhancement and safety-assurance of aging airplanes, the Federal Aviation Administration sponsored a symposium in Atlanta, GA, USA, during 20-22 March 1990. This symposium, under the title "International Symposium on Structural Integrity of Aging Airplanes. was organized jointly be the Georgia Institute of Technology (Center for Computational Mechanics) and the Transportation Systems Center (Cambridge, MA) of the U.S. Department of Transportation. Industrial and academic experts from several countries in North America, Europe and Asia, were invited to discuss their experiences and proposed solutions. This monograph contains the original papers that represent the expanded and edited versions of the talks presented at this symposium. This book aims to bring the collective experience, from across the world, with problems related to the structural integrity of aging airplanes to the attention of the professional and research community at large - in the hope that it may stimulate further fruitful research on this important topic of global concern."

Many mechanical systems are actively controlled in order to improve their dynamic performance. Examples are elastic satellites, active vehicle suspension systems, robots, magnetic bearings, automatic machine tools. Problems that are typical for mechanical systems arise in the following areas: - Modeling the mechanical system in such a way that the model is suitable for control design - Designing multivariable controls to be robust with respect to parameter variations and uncertainties in system order of elastic structures - Fast real-time signal processing - Generating high dynamic control forces and providing the necessary control power - Reliability and safety concepts, taking into account the growing role of software within the system The objective of the Symposium has been to present methods that contribute to the solutions of such problems. Typical examples are demonstrating the state of the art It intends to evalua~ the limits of performance that can be achieved by controlling the dynamics, and it should point to gaps in present research and areas for future research. Mainly, it has brought together leading experts from quite different areas presenting their points of view. The International Union of Theoretical and Applied Mechanics (lUTAM) has initiated and sponsored, in cooperation with the International Federation of Automatic Control (IF AC), this Symposium on Dynamics of Controlled Mechanical Systems, held at the Swiss Federal Institute of Technology (ETH) in Zurich, Switzerland, May 3D-June 3, 1988.

This volume is the result of an international collaboration, which started with a conference at Smadalaro Gfrrd in Sweden. The workshop was supported by the National Science Foundation of the USA (INT-9215114) and by the Swedish National Road Administration, the Swedish Council for Building Research, the Swedish Transport and Communications Research Board and the Swedish Council for Planning and Coordination of Research. This support is gratefully acknow ledged. The collaboration started as a bilateral u.S.-Swedish endeavour but was soon widened to other scholars in Europe, Asia, Australia and South-America. Network Infrastructure and the Urban Environment is a policy area of growing importance. Sustainable cities and sustainable transport systems are necessary for attaining a sustainable development. The research and policy field, represented in this volume, comprises a number of challenging contrasts: - the contrast between infrastructure investments, mobility and environmental sustainability; - the contrast between policy contexts, modelling traditions and available decision support systems in various parts of the world; - the contrast between available best practice methods and the majority of models applied in planning; the contrast between static models of cross-sectionary equilibria and dynamic models of disequilibrium adjustments; and the contrast between state-of-the-art operationalland-use/transport models and new demands for land-use/transportlenvironment models due to changing policy contexts. Bridging some of these gaps constitutes important research tasks, that are discussed in the twenty-two chapters of this book. A number of emerging research directions are identified in the introduction and summary chapter."

Gravity models describe, and hence help predict, spatial flows of commuters, air-travelers, migrants, commodities and even messages. They are one of the oldest and most widely used of all social science models. This book presents an up-to-date, consistent and unified approach to the theory, methods and application of the gravity model - which spans from the axiomatic foundations of such models all the way to practical hints for their use. "I have found no better general method for use in applied research dealing with spatial interaction... It is against this background that the present book by Sen and Smith is most welcomed." "Walter Isard"

Microsystems are an important success factor in the automobile industry. In order to fulfil the customers requests for safety convenience and vehicle economy, and to satisfy environmental requirements, microsystems are becoming indispensable. Thus a large number of microsystem applications came into the discussion. Some examples are sensors for engine management, exhaust and air quality control, immobilizers, ABS, anti skid (ASC) and vehicle dynamics control (VDC), smart airbag systems and other safety applications as obstacle detection and vision enhancement. With the international conference AMAA '98, VDI/VDE-IT provides a platform for the discussion of all MST relevant components for automotive applications. The conference proceedings gather the papers by authors from automobile suppliers and manufacturers.

In recent years more emphasis has been placed in transport research on using existing roads as efficiently as possible in order to diminish the impact of traffic congestion. This book describes new theoretical, empirical and simulation models to analyse the impact of information provision to drivers and road pricing on congestion levels. It is the first publication presenting a wide variety of economic models to study information and road pricing effects jointly.

The present book contains the papers that have been presented at the IUTAM-Symposium on Atmospheric Dispersion of Heavy Gases and Small Particles, which was held from August 29th to September 2nd 1983 in Scheveningen in The Netherlands. Attendees from many countries were present; 4 review lectures and about 25 research papers were presented. The realization of the symposium was made possible by the support of Delft University of Technology Koninklijke/Shell-Laboratory Amsterdam Prins Maurits Laboratory/Institute for Chemical and Technological Research Royal Netherlands Meteorological Institute. The symposium organization was carried out by the local organi- zing committee consisting of F.G.J. Absil - Delft University of Technology G.W. Colenbrander - Koninklijke/Shell-Laboratory Amsterdam G. Ooms - Delft University of Technology G. Opschoor - Prins Maurits Laboratory/Institute for Chemical and Technological Research H. Tennekes - Royal Netherlands Meteorological Institute A.P. van Ulden - Royal Netherlands Meteorological Institute. The work of the organizing committee was supported in many re- spects by the sientific committee, which consisted of H. Fiedler - Technische Hochschule Karlsruhe, Fed. Rep. of Germany F.N. Frenkiel - Naval Ship Research and Development Center, Bethesda, Maryland, U.S.A. J.C.R. Hunt - University of Cambridge, England J. Kondo - National Institute for Environmetal Studies, Japan J.L. Lumley - Cornell University, Ithaca, New York, U.S.A.

This monograph is an attempt to compile the present state of knowledge on ocean wave analysis and prediction. The emphasis of the monograph is on the development of ocean wave analysis and predic tion procedures and their utility for real-time operations and appli cations. Most of the material in the monograph is derived from journal articles, research reports and recent conference proceedings; some of the basic material is extracted from standard text books on physical oceanography and wind waves. Ocean wave analysis and prediction is becoming an important activity in the meteorological and oceanographic services of many countries. The present status of ocean wave prediction may be compar able to the status of numerical weather prediction of the mid-sixties and early seventies when a number of weather prediction models were developed for research purposes, many of which were later put into operational use by meteorological services of several countries. The increased emphasis on sea-state analysis and prediction has created a need for a ready reference material on various ocean wave analysis and modelling techniques and their utility. The present monograph is aimed at fulfilling this need. The monograph should prove useful to the ocean wave modelling community as well as to marine forecasters, coastal engineers and offshore technologists. The monograph could also be used for a senior undergraduate (or a first year graduate) level course in ocean wave modelling and marine meteorology.

The Symposium "Aero-and Hydroacoustics" was held at the Ecole Centrale de Lyon, France, on 3rd - 6 July 1985, at the initiative of the International Union of Theoretical and Applied Mechanics (IUTAM) . The research topics discussed concerned the acoustics of unstable and turbulent flows and the noise generated by movable surfaces. Other subjects of interest were thermoacoustics, diffraction, and acoustic propagation through turbulence. Applications of numerical and experimental techniques to source diagnostics were discussed, as was active noise control. In Hydroacoustics the emphasis was on noise due to flow induced vibrations. There were 8 general invited lecturers and 43 other contributors, with 150 participants form 14 countries. Sufficient time was provided for discussions and social gatherings. For example, there was the opening of the high speed anechoic wind tunnel of the Centre Acoustique, and a welcome address given by the Mayor of Lyon in his historic City Hall. The organizing Committee of the Symposium wish to express their thanks to la Direction des Recherches Etudes et Techniques du Ministere des Armees (DRET), Ie Centre National de la Recherche Scientifique (CNRS), Ie Conseil General du Rhone, l'Association Universitaire de Mecanique (AUM), Ie Ministere de l'Environnement, for financial support. Le Groupement des Acousticiens de langue frangaise (GALF) helped advertise the meeting. The organizers are also indebted to the International Union of Theoretical and Applied Mechanics for providing travel subsidies to young scientists.

The book is based on an international workshop on High Precision Navigation. The reader will find a wealth of information on - satellite navigation systems and their geodetic applications, especially using GPS - laser and radar techniques - image processing and image sequence analysis - autonomous vehicle guidance systems - inertial navigation systems - integration of different sensor systems.

Among the many techniques for designing linear multivariable analogue controllers, the two most popular optimal ones are H2 and H-infinity optimization. The fact that most new industrial controllers are digital provides strong motivation for adapting or extending these techniques to digital control systems. This book, now available as a corrected reprint, attempts to do so. Part I presents two indirect methods of sampled-data controller design: These approaches include approximations to a real problem, which involves an analogue plant, continuous-time performance specifications, and a sampled-data controller. Part II proposes a direct attack in the continuous-time domain, where sampled-data systems are time-varying. The findings are presented in forms that can readily be programmed in, e.g., MATLAB.

At the suggestion of the USSR National Committee of Theo retical and Applied Mechanios the International Union of Theo retical and Applied Meohanics made a deoision to organize the Second IUTAM Symposium on Laminar-Turbulent Transition in No vosibirsk. Professor Yanenko was entrusted to be the chairman of the scientific committee. It was proposed that about 100 scientists would participate in the Symposium and that 60 lectures and invited lectures would be delivered; as for the theme of the Symposium, it was devoted to experimental and theoretical stu dies of laminar-turbulent transition in fluids and gases, i.e. the physical problems of transition and mathematical modeling in shear flows. It was planned to lay a special emphasis on fundamental mechanisms of the transition process. The scienti fio committee approved of the scope of the Symposium having considered the changes in the directions of the stUdies which took place since the First Symposium. For example, there was singled out the problem of transformation of external distur bances into eigenoscillations of shear flows, i.e. the recep tivity problem which was only slightly touched upon at the First Symposium. A new section appeared devoted to the inter relation of the flow separation phenomenon and its stability. It was planned to focus the attention on the secondary instability at transition to turbulence at the non-linear stage of the flow breakdown as well as on the loss of stability and the disturbances development in 3-D flows."

Investigation of vortex wakes behind various aircraft, especially behind wide bodied and heavy cargo ones, is of both scientific and practical in terest. The vortex wakes shed from the wing's trailing edge are long lived and attenuate only atdistances of10-12kmbehindthe wake generating aircraft. The encounter of other aircraft with the vortex wake of a heavy aircraft is open to catastrophic hazards. For example, air refueling is adangerous operationpartly due to thepossibility of the receiver aircraft's encountering the trailing wake of the tanker aircraft. It is very important to know the behavior of vortex wakes of aircraft during theirtakeoff andlanding operations whenthe wakes canpropagate over the airport's ground surface and be a serious hazard to other depart ing or arriving aircraft. This knowledge can help in enhancing safety of aircraft's movements in the terminal areas of congested airports where the threat of vortex encounters limits passenger throughput. Theoreticalinvestigations of aircraft vortex wakes arebeingintensively performedinthe major aviationnations.Usedforthispurpose are various methods for mathematical modeling of turbulent flows: direct numerical simulation based on the Navier-Stokes equations, large eddy simulation using the Navier-Stokes equations in combination with subrigid scale modeling, simulation based on the Reynolds equations closed with a differential turbulence model. These approaches are widely used in works of Russian and other countries' scientists. It should be emphasized that the experiments in wind tunnels and studies of natural vortex wakes behind heavy and light aircraft in flight experiments are equally important.

Software Diversity is one of the fault-tolerance means to achieve dependable systems. In this volume, some experimental systems as well as real-life applications of software diversity are presented. The history, the current state-of-the-art and future perspectives are given. Although this technique is used quite successfully in industrial applications, further research is necessary to solve some open questions. We hope to report on new results and applications in another volume of this series within some years. Acknowledgements The idea of the workshop was put forward by the chairpersons of IFIP WG lOA, J. -c. Laprie, J. F. Meyer and Y. Tohma, in January 1986, and the edi tor of this volume was asked to organize the workshop. This volume was edited with the assistance of the editors of the series, A. AviZienis, H. Kopetz and J. -C. Laprie, who also had the function of reviewers. Karlsruhe, October 1987 U. Voges, Editor Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1. Introduction U. Voges 2. Railway Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 ERICSSON Safety System for Railway Control . . . . . . . . . . . . . . . . . . 11 G. Hagelin 3. Nuclear Applications . . . . . . . . . . . . . . . . . . . . . . 23 Use of Diversity in Experimental Reactor Safety Systems . 29 U. Voges The PODS Diversity Experiment . 51 P. G. Bishop 4. Flight Applications . . . . . . . . . . . . . . . . . . . . . . . . . 85 AIRBUS and ATR System Architecture and Specification. . 95 P. Traverse 5. University Research . . . . . . . . . . . . . . . . . . . 105 Tolerating Software Design Faults in a Command and Control System . . . . . . . . . . . . . . . . . . . . . . 109 T. Anderson, P. A. Barrett, D. N. Halliwell, M. R. Moulding DEDIX 87 - A Supervisory System for Design Diversity Experiments at UCLA . . . . . . . . . . . . . . . . . ."

This research monograph presents a systematic treatment of the theory of the propagation of transient electromagnetic fields (such as optical pulses) through dielectric media which exhibit both dispersion a.nd absorption. The work divides naturally into two parts. Part I presents a summary of the fundamental theory of the radiation and propagation of rather general electromagnetic waves in causal, linear media which are homogeneous and isotropic but which otherwise have rather general dispersive and absorbing properties. In Part II, we specialize to the propagation of a plane, transient electromagnetic field in a homogeneous dielectric. Although we have made some contributions to the fundamental theory given in Part I, most of the results of our own research appear in Part II. The purpose of the theory presented in Part II is to predict and to explain in explicit detail the dynamics of the field after it has propagated far enough through the medium to be in the mature-dispersion regime. It is the subject of a classic theory, based on the research conducted by A. Sommerfeld and L.

As European countries pursue a common effort towards establishing a European Union, various isolated -and consequently disadvantaged -regions are likely to face increasing competitive pressures due to their peripheral location. To assist such areas, regional, national and supranational bodies put much effort into developing transport and communication networks and linkages in order to ensure that such less favoured areas are better integrated in the broader European social and economic development process. This book addresses the issue of lagging development in various -mainly central and southern - European regions which are in a disadvantageous position as a result of their isolated 10cation...The persisting problems of social and economic development in several European Union areas (e.g. islands, mountains, border areas) has turned the attention of policy-makers to "the critical importance of transport and (tele)communication linkages. The purpose of the book is to bring into perspective the role of transport and communications in regional policy for peripheral areas. This subject is currently of high priority, since the European Union through the Structural Funds interventions (i.e. the Community Support Frameworks) and the new Cohesion Fund relies heavily on transport and communication infrastructure investments to assist areas which are at a disadvantage due to their peripheral location and isolation. Furthermore, as the Union considers enlargement, some of these issues might be of wide European interest."

This is the second part of the translation of the original German text Meerestechnische Konstruktionen which was published by Springer-Verlag in 1988. The translated material is a reviewed and updated version of the German text. Wheras the first volume concentrates on general and external factors, this one focuses on factors affecting the design and analysis of offshore structures themselves. In an effort to address a wide audience the topic is presented in a general context. Therefore it introduces students and practising engineers to the field of marine technology and, at the same time, serves as a reference book for experts. Finally it gives specialists in related fields an idea of where their work on individual problems of offshore structures stands in relation to the field as a whole. Offshore Structures, Vol. 2 is based on the authors' lectures and design practice in offshore structures and their components. It assists the reader in developing practical solutions by introducing a large number of examples and reference is made to further specialised literature.

The concept of traffic conflict was initiated in the Uni ted States in the 60s and raised a lot of interest in many countries: it was an opening towards the develop ment of a new tool for safety evaluation and the diagnosis of local safety pro blems. The need for such a tool was great, because of the many situations where accident data was either scarce, unsatisfactory or unavailable. Development of Traffic Conflict Techniques (TCT) started simultaneously in the 70s in several European count ries and new studies were also undertaken in the Uni ted States, Canada and Israel. The need for international cooperation was rapidly feIt, in order to exchange data, compare definitions and check progresses. An Association for International Cooperation on Traffic Conflict Techniques (ICTCT) was therefore created, grouping researchers and safety administrators, with the aim of promoting and organising exchange of information and common practical work. Three Traffic Conflict Techniques Workshops were organised, in Oslo (1977), Paris (1979) and Leidschendam (1982). A small scale international experiment of calibra tion of TCTs was also carried out in Rouen, France, in 1979, and five teams took part in it from France, Germany, Sweden, the United Kingdom and the United States; results of this first experiment were used as a basis for the present enterprise. To be acknowledged as a safety measuring tool, traffic conflict techniques had to be validated in relation to traditional safety indicators such as injury-accidents."

Welcome to Bavaria - Germany - to the THIRD EUROPEAN CARS/TRUCKS SIMULATION SYMPOSIUM. That Schliersee traditional workshop-type meeting is a follow-up to the first and the second symposia which took place in May 1984 and May 1989 respectively. The objective of gathering together is to cover most of the aspects of Automotive Mathematical Modelling and Simulation in theory and practice to promote the exchange of knowledge and experience between different national and international research groups in that field, taking into consideration that every seventh German employee is related to the automotive industry. This effect is also in power at least with the traditional Detroit (U.S.A.) Automotive Industries and the growing up Japanease as well. Futhermore, there is to strenghten the international contact between developers and users of modelling and simulation techniques considering the "new world order" started in 1991 with no borders between West and East affected by the Golf-War and followed up by the "open" European Community borders of 1992. VI The traditional International Conference jointly promoted by ASIMUTH - Applied Simulation Technology and some other members of the Society of Computer Simulaton created an interest to publish new projects including their results. A large number of contributed papers has been strictly examined and selected by the editorial commitee to guarantee a high international technical standard.

Separated flows and jets are closely linked in a variety of applications. They are of great importance in various fields of fluid mechanics including vehicle efficiency, technical branches concerned with gas/liquid flows, atmospheric effects on various constructions, etc. Knowledge of the physics of separated flows and jets and the development of reliable control techniques are prerequisite for future progress in the field. These aspects were in focus during the IUTAM-Symposium which was held in Novosibirsk, 9-13 July, 1990. This volume contains a selection of papers presenting recent results of theoretical and numerical studies as well as experimental work on separated flows and jets. The topics include sub- and supersonic, laminar and turbulent separation as well as organized structures in separated flows and jets. The reader will find here the state of the art and major trends for research in this field of aero-hydrodynamics.