For four decades, information theory has been viewed almost exclusively as a theory based upon the Shannon measure of uncertainty and information, usually referred to as Shannon entropy. Since the publication of Shannon's seminal paper in 1948, the theory has grown extremely rapidly and has been applied with varied success in almost all areas of human endeavor. At this time, the Shannon information theory is a well established and developed body of knowledge. Among its most significant recent contributions have been the use of the complementary principles of minimum and maximum entropy in dealing with a variety of fundamental systems problems such as predic tive systems modelling, pattern recognition, image reconstruction, and the like. Since its inception in 1948, the Shannon theory has been viewed as a restricted information theory. It has often been argued that the theory is capable of dealing only with syntactic aspects of information, but not with its semantic and pragmatic aspects. This restriction was considered a v~rtue by some experts and a vice by others. More recently, however, various arguments have been made that the theory can be appropriately modified to account for semantic aspects of in formation as well. Some of the most convincing arguments in this regard are in cluded in Fred Dretske's Know/edge & Flow of Information (The M.LT. Press, Cambridge, Mass., 1981) and in this book by Guy lumarie.

This book studies language behaviour in the larger context of modelling or ganismic behaviour more generally. It starts out from the basic premise that what is characteristic of organismic behaviour is that an organism uses its behavioural acts to accomplish something in its interactions with the world in which it finds itself. These two features, that an organism has a behav ioural repertoire and that it deploys specific behavioural acts from its repertoire in an intentional way, define the agentive nature of an organism. The study of organismic behaviour, then, must primarily concern itself with this agentive aspect of an organism and determine what structures and proces ses underlie these intentional organismic acts. We should be able to say what primitive structures and what primitive processes put together in what ways can give rise to the kinds of behavioural acts an organism engages in. Any explanation of behaviour that we formulate in terms of underlying structures and processes must be testable and must be consonant with the observed pheno menological aspects of such behaviour."

For a system consisting of a random medium with rough boundaries, the governing (Bethe-Salpeter) equation for boundary-value transport problems can be written in a form such that the medium and the boundaries are treatedon an equal footing. This enables several expressions for the solution to be obtained by interchanging the roles of the medium and the boundaries, thus allowing the most convenient one to be selected according to the specific situation and the information required. This book presents a unified theory based on the Bethe-Salpeter equation with particular attention being paid to: boundary-value problems of transport, layer problems, a fixed scatterer imbedded in a bounded random medium, construction of an optical scattering matrix for a complete system, and optical wave propagation in a turbulent medium. The last topic is treated in terms of first moment equations combined with the cluster expansion and, second, the two-scale method based on the Lagrange variational principle.

Medical applications of ultrasound range from therapy, foetal monitoring, diagnostic imaging and blood flow measurement, to surgery and lithotripsy. Ever since the earliest developments of medical ultrasound there has been an interest in the measurement and characterisation of the ultrasonic fields generated in these applications, either for assessment of performance of equipment or for safety. Until recently, procedures for acoustic output measurements were ill-defined, but standards are now being developed internationally by the International Electrotechnical Commission (1EC) and reliable commercial measuring equipment is becoming more widely available. The aim of this book is to introduce acoustic output measurement techniques and to provide an insight into the measurement methods. The material presented is based on a course originally run during November 1989 at the National Physical Laboratory. In addition to the lectures, the course consisted of a series of practicals to allow participants to gain experience of making measurements. Teddington, UK Roy C. Preston February 1991 Contents List of Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii List of Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 Safety of Diagnostic Ultrasonic Equipment: The Relevance of Acoustic Output Information to the Clinical User R. C. Preston 1. 1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1. 2 The Relevance of Acoustic Output Information. . . . . . . . . . . . . 6 1. 2. 1 What Is Acoustic Output Information? . . . . . . . . . . . . . . . . . . . 6 1. 2. 2 What Is Acoustic Output Information Used For? . . . . . . . 6 1. 2. 3 Why Should You Know the Acoustic Output Levels of Your Equipment? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1. 2. 4 Are Acoustic Output Levels Really that Important? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

"Principles of Statistical Radiophysics" is a four-volume series that introduces the newcomer to the theory of random functions. It aims at providing the background necessary to understand papers and monographs on the subject and to carry out independent research in the fields where fluctuations are of importance, e.g. radiophysics, optics, astronomy, and acoustics. Volume 3, "Elements of Random Fields," gives the basic mathematical definitions, general properties and specific forms of random fields, the generalization from correlation theory to random fields. It deals with stochastic partial differential equations, wave scattering at a chaotic screen, single scattering in random media and thermal fluctuations and radiation of electromagnetic fields.

Power Transducers for Sonics and Ultrasonics approaches all aspects of high-power problems in electroacoustic transducers. The eighteen lectures contained in this book focus on topics in sonar and macrosonic transducer design, new material developments for transducers, transducer modelling, and power electronics. Possible future trends and developments are outlined.

This book contains the proceedings of an IUTAM Symposium on turbulent flows at low Mach number, in which fluctuations in density occur as a result of heat transfer or of mixing of different fluids. Such flows occur in the atmosphere, the ocean, and in chemical engineering. In addition, in combustion large fluctuations in density occur as a result of heat release; the flows that are considered here do not involve heat release, for the most part, but the variable density flows that are considered can serve as a paradigm for many of the problems that arise in combustion as a result of the density fluctuations. Compressible flows - such as supersonic ones - are also considered in order to underline their similarities to and their differences from low-speed variable density flows. The book will be of interest to mechanical, aerospace, civil, and chemical engineers, meteorologists and oceanographers - in fact, anyone who deals with fluids in which fluctuations of density occur. The book will be accessible to professional and graduate students. There are no other works that deal with this interesting area.

The scientific study of speech production has been undertaken within a variety of disciplines, including linguistics, physiology, physical acoustics, and psychology, among others. In recent years, it has become possible to combine the knowledge accumulated within these separate disciplines to gain more insight into the nature of this complex human activity. Here, we apply an interdisciplinary focus to one of the most widely discussed and poorly under stood aspects of the speech signal. This study of fundamental voice frequency involves a mixture of linguistics, physical acoustics, and psychology. The rele vant aspects of each discipline are introduced in Chapter 1 so that readers with minimal background in at least one of these areas should be able to compre hend much of the whole. This book is written primarily as an original research treatise rather than as a review of the literature. However, many previous studies of fundamental fre quencyare discussed here, and the book should serve as both a reference source and a supplementary text in courses on speech communication taught within a number of disciplines. Because of the complexity of Fo patterns, graphical displays of the results playa particularly important role in this presentation. While the results of each experiment are summarized and discussed verbally within the text, the graphical displays, by comparison, represent a more inte gral part of this book than is often the case in treatments of speech production."

Music is an important domain of application for schema theory. The perceptual structures for pitch and timbre have been mapped via schemata, with results that have contributed to a better understanding of music perception. Yet we still need to know how a schema comes into existence, or how it functions in a particular perception task. This book provides a foundation for the understanding of the emergence and functionality of schemata by means of computer-based simulations of tone center perception. It is about how memory structures self-organize and how they use contextual information to guide perception.

Recently, there have been significant advances in the fields of high-enthalpy hypersonic flows, high-temperature gas physics, and chemistry shock propagation in various media, industrial and medical applications of shock waves, and shock-tube technology. This series contains all the papers and lectures of the 19th International Symposium on Shock Waves held in Marseille in 1993. They are published in four topical volumes, each containing papers on related topics, and preceded by an overview written by a leading international expert. The volumes may be purchased independently.

This volume contains the Proceedings of the International Workshop on the Design of Power Sonic and Ultrasonic Transducers, which was held in the Maison de l'Entreprise et des Technologies Nouvelles, Marcq en Baroeul, near Lille, France, on May 26 and 27, 1987. The main objective of this Workshop was to discuss all aspects of high power problems in the design of electroacoustic transducers and to stimulate an exchange of knowledge and experience between researchers and industrial ists involved in this multidisciplinary field. The scientific program included 13 invited contributions, and there were 80 participants from England, France, Italy, Spain, Sweden and the United States. The editors wish to thank the authors and attendees for their active par ticipation, and they hope that these Proceedings will allow readers to share in the stimulating atmosphere of the sessions. They also wish to thank eve ryone who undertook simultaneous translation, clerical work, typing of the Proceedings, production of the illustrations, or any other of the numerous tasks connected with this venture. Special mention has to be made of Mrs. E. Litton (ISEN, Lille) for her constant and kind help from the beginning of the project to the very end of the editing, Dr. R. Bossut (ISEN, Lille) for his efficient proofreading, and Dr. H.U. Daniel (Springer-Verlag) for his interest in these Proceedings as well as his kind and efficient support.

The area of concern to Dr. Wietske Noordman~Vonk has been variously seen as an aspect of long-term memory [F. I], secondary memory [F. 2], memory without record [F. 3], and semantic memory [F. 4J, the latter term being the one pre ferred by Dr. Noordman-Vonk herself. This proliferation of terminology is not an entirely trivial matter, for although the expressions clearly overlap in range, they do draw attention to different features of the phenomena under consideration. The work reported here is concerned with the form of representation and manipulation of our knowledge that, for example, a dog is an animal, or that mothers and daughters are parents and children. To put it more generally, the experiments attempt to elucidate the psychological processes involved in the~emantics of class-inclusion and, most importantly, to extend the explanatory principles there invoked to a new domain, that of kinship relations. Clearly, the connections between "ant" and "insect", or "flower" and "plant" have been known to us - as adults - for some considerable period of time; in the absence of brain injury or degeneration we are unlikely to "forget" that fathers and sons are kin of the same sex. We may therefor- pretheoretically - distinguish between retrieval of such knowledge and. re trieval of a rapidly fading sequence of random numbers that we are asked to recall after a single presentation. It is in this sense that the current work is concerned with long-term and not short-term memory.

Prosody: Models and Measurements is the fruit of a three-day workshop held in Paris in April, 1982. The workshop was one of a series which is sponsored by the Maison des Sciences de I'Homme under the auspices of the European Psycho linguistics Association, and which aims to bring together workers in a particular field from different European laboratories and to encourage future collaboration across regional, national and disciplinary boundaries. Thus the topic of the workshop - "Prosody" - was fairly liberally interpreted in the invitations, and the participants were drawn from a variety of background- linguistics, phonetics, psychology. Despite this diversity, however, there was a surprising degree of congruence in the topics discussed and points of view adopted. We have attempted in the introduction to the present volume to as well as to account for the draw out the similarities between approaches, differences and to set the individual contributions against the background of current research in the field. The book is not merely a transcript of what was said during the sessions. All of the papers have been rewritten by the participants - in some cases extensively - to reflect the comments that were made in discussion and the points of contact and disagreement that became evident during the three days.

This book has been written as part of a new series of scientific text-books being published by Plenum Publishing Company Limited. The scope of the series is to review a chosen topic in each volume, and in addition, to present abstracts of the most important references cited in the text. Thus allowing the reader to supplement the information contained within this book without have to refer to many additional publications. This volume is devoted to the subject of Radiation Detectors, known as Photodetectors, and particular emphasis has been placed on devices operating in the infrared region of the electromagnetic spectrum. Although some detectors which are sensitive at ultraviolet and visible wavelengths, are also described. The existence of the infrared region of the spectrum has been known for almost two hundred years but the development of detectors specifically for these wavelengths was limited for a long time due to technology limitations and difficulties in understanding and explaining the phenomena involved. Significant advances were made during World War II, when the potential military applications of being able "to see in the dar ' were demonstrated, and this progress has been maintained during the last forty years when many major advances have been achieved, such that the use of photodetectors for both civil and military applications is now relatively common and can be inexpensive.

The theory of linear discrete time filtering started with a paper by Kol mogorov in 1941. He addressed the problem for stationary random se quences and introduced the idea of the innovations process, which is a useful tool for the more general problems considered here. The reader may object and note that Gauss discovered least squares much earlier; however, I want to distinguish between the problem of parameter estimation, the Gauss problem, and that of Kolmogorov estimation of a process. This sep aration is of more than academic interest as the least squares problem leads to the normal equations, which are numerically ill conditioned, while the process estimation problem in the linear case with appropriate assumptions leads to uniformly asymptotically stable equations for the estimator and the gain. The conditions relate to controlability and observability and will be detailed in this volume. In the present volume, we present a series of lectures on linear and nonlinear sequential filtering theory. The theory is due to Kalman for the linear colored observation noise problem; in the case of white observation noise it is the analog of the continuous-time Kalman-Bucy theory. The discrete time filtering theory requires only modest mathematical tools in counterpoint to the continuous time theory and is aimed at a senior-level undergraduate course. The present book, organized by lectures, is actually based on a course that meets once a week for three hours, with each meeting constituting a lecture."

The Fourier transform technique has been widely used in electrical engineer ing, which covers signal processing, communication, system control, electro magnetics, and optics. The Fourier transform-technique is particularly useful in electromagnetics and optics since it provides a convenient mathematical representation for wave scattering, diffraction, and propagation. Thus the Fourier transform technique has been long applied to the wave scattering problems that are often encountered in microwave antenna, radiation, diffrac tion, and electromagnetic interference. In order to u derstand wave scattering in general, it is necessary to solve the wave equation subject to the prescribed boundary conditions. The purpose of this monograph is to present rigorous so lutions to the boundary-value problems by solving the wave equation based on the Fourier transform. In this monograph the technique of separation of vari ables is used to solve the wave equation for canonical scattering geometries such as conducting waveguide structures and rectangular/circular apertures. The Fourier transform, mode-matching, and residue calculus techniques are applied to obtain simple, analytic, and rapidly-convergent series solutions. The residue calculus technique is particularly instrumental in converting the solutions into series representations that are efficient and amenable to nu merical analysis. We next summarize the steps of analysis method for the scattering problems considered in this book. 1. Divide the scattering domain into closed and open regions. 2. Represent the scattered fields in the closed and open regions in terms of the Fourier series and transform, respectively. 3."

This book presents a collection of papers from the Spring 1995 Work shop on Computational Approaches to Processing the Prosody of Spon taneous Speech, hosted by the ATR Interpreting Telecommunications Re search Laboratories in Kyoto, Japan. The workshop brought together lead ing researchers in the fields of speech and signal processing, electrical en gineering, psychology, and linguistics, to discuss aspects of spontaneous speech prosody and to suggest approaches to its computational analysis and modelling. The book is divided into four sections. Part I gives an overview and theoretical background to the nature of spontaneous speech, differentiating it from the lab-speech that has been the focus of so many earlier analyses. Part II focuses on the prosodic features of discourse and the structure of the spoken message, Part ilIon the generation and modelling of prosody for computer speech synthesis. Part IV discusses how prosodic information can be used in the context of automatic speech recognition. Each section of the book starts with an invited overview paper to situate the chapters in the context of current research. We feel that this collection of papers offers interesting insights into the scope and nature of the problems concerned with the computational analysis and modelling of real spontaneous speech, and expect that these works will not only form the basis of further developments in each field but also merge to form an integrated computational model of prosody for a better understanding of human processing of the complex interactions of the speech chain."

The large number of text books on the theory of sound deal principally with periodic disturbances such as harmonic wave trains and standing waves and give scant attention to aperiodic disturbances with clearly defined fronts, conveniently called sound pulses. This monograph attempts to fill this gap by providing an up-to-date description of the theory of sound pulses and its developments. The treatment is based on the thoery of linear partial differential equations of hyperbolic type - a method which is frequently simpler and more effective than the commoner one of resolving the pulse into harmonic components by Fourier analysis; this is especially true of any treatment of pulse fronts as wave fronts in the sense of geometrical optics. The individual chapters deal with the equations of motion, wave fronts and characteristics, geometrical acoustics and their application to reflection problems and the diffraction of a pulse by a wedge, circular cylinder, sphere and other objects. The book will also be of interest to readers concerned with other aspects of wave propagation, such as electromagnetic waves.

Since the 1950s shock compression research contributed greatly to scientific knowledge and industrial technology. As a result, for example, our understanding of meteorite impacts has substantially improved, and shock processes have become standard industrial methods in materials synthesis and processing. Investigations of shock-compressed matter involve physics, electrical engineering, solid mechanics, metallurgy, geophysics and materials science. The description of shock-compressed matter presented here, which is derived from physical and chemical observations, differs significantly from the classical descriptions derived from strictly mechanical characteristics. This volume, with over 900 references, provides an introduction for scientists and engineers interested in the present state of shock compression science

IJ:1 June of 1987 the Center for Applied Mathematics and Computer Science at San Jose State University received a bequest of over half a million dollars from the estate of Mrs. Marie Woodward. In the opening article of this collection of papers Jane Day, the founder of the Center, describes the background that led to this gift. In recognition of the bequest it was decided that a series of Woodward Conferences be established. The First Woodward Conference took place at San Jose State University on June 2-3 1988. The themes of the conference were the Theoretical, Computational and Practical Aspects of Wave Phenomena and these same themes have been used to divide the contributions to this volume. Part I is concerned with papers on theoretical aspects. This section includes papers on pseudo-differential operator techniques, inverse problems and the mathematical foundations of wave propagation in random media. Part II consists of papers that involve significant amounts of computation. Included are papers on the Fast Hartley Transform, computational algorithms for electromagnetic scattering problems, and nonlinear wave interaction problems in fluid mechanics. vi Part III contains papers with a genuine physics flavor. This final section illustrates the widespread importance of wave phenomena in physics. Among the phenomena considered are waves in the atmosphere, viscous fingering in liquid crystals, solitons and wave localization.

This work marks a stage in the evolution of a scientific and technical field which has been developed by the Commissariat a l'Energie Atomique (CEA) over several decades. Many members of the staff of the CEA have won re nown in this field, and their work has brought it to the high degree of excel lence for which it is internationally recognized today. These scientists had to consider every aspect of the field, as it concerned: modeling, which has recourse to fluid thermodynamics, molecular phys ics, and chemistry; numerical evaluation, which relies on mathematical analysis and data processing; and experiments in the firing area, which require specific stress generators and instrumentation. Whilst this book is a testament to the activity and success of staff of the CEA, it also reviews a number ofthe advances made in the discipline. How ever, it is not intended to be an exhaustive account of those advances; it is assumed that the reader can, if desired, consult the standard monographs, and more recent, more specialized works (notably W.C. Davis and W. Fickett, and C.L. Mader). The history of the discipline is interesting in itself, and also as an illustra tion of the causes which lead to progress in a coherent body of scientific work. I should like to make some comments on this progress, of which there is a fascinating summary in the introduction, and which will figure largely throughout the work."

In its relentless pursuit of further knowledge, science tends to compartmentalize. Over the years the pursuit of What might be called geophysical acoustics of the sea-surface has languished. This has occured even through there are well-developed and active research programs in underwater acoustics, ocean hydrodynamics, cloud and precipitation physics, and ice mechanics - to name a few - as well as a history of engineering expertise built on these scientific fields. It remained to create a convergence, a dialogue across disciplines, of mutual benefit. The central theme of the Lerici workshop, perhaps overly simplified, was 'What are the mechanisms causing ambient noise at the upper surface of the ocean?' What could hydrodynamicists contribute to a better understanding of breaking wave dynamics, bubble production, ocean wave dynamics, or near-surface turbulence for the benefit of the underwater acoustics community? What further insights could fluid dynamicists gain by including acoustic measurements in their repertoire of instrumentation? While every attendee will have his or her percep tions of details, it was universally agreed that a valuable step had been taken to bring together two mature disciplines and that significant co-operative studies would undoubtedly follow. The scope of the workshop was enlarged beyond its original intent to also include the question of ice-noise generation. The success of this decision can be seen in high quality of the presentations. the contribution of its disciples in the other workshop discussions and the heightened awareness and interest of we other novices."

Anybody concerned about the maintenance of peace in our world, and in prospects of reaching agreements on arms control and disarmament, is bound to be interested in one of the key pre-conditions for related international treaties: the verification of compliance with such treaties. This book presents an up-to-date exposition of the latest developments in science and practice of international verification. It contains an account of the experience with new practical results of scientific research, devoted to solving verification problems in areas where agreements have not yet been concluded. The authors are scientists and practitioners from governments and research institutes in East and West. This book is required reading for anybody interested in the field: especially for decision-makers, government and military experts, natural scientists, technologists, those working in political and historical science. Among the topics covered are: INF Treaty, nuclear test ban, control of mobile missiles, and fissile material, demilitarization of space, stability and reductions of conventional forces, ban on chemical weapons. From the Reviews: ""Verfication of Arms " "Reductions" is packed with information and analysis which is vital for arms-control students, negotiators and other practitioners. The strength of the book lies in the science and technology contributions, but there are comprehensive political analyses also which have been written for longevity and are unlikely to become dated too quickly."

A fundamental problem in cell biology is the cause of aging. The solution to this problem has not yet been obtained because, (l) until recently, it was not possible to image living cells directly. The use of low-energy (soft) X rays has made such imaging possible, perhaps thereby allowing the aging process to be understood and possibly overcome (a result that may well generate further social, moral, and ethical problems). Fortun ately this is not the only aspect of cell biology amenable to soft X-ray imaging, and it is envisaged that many less controversial studies--such as investigations of the detailed differences between healthy and diseased or malignant cells (in their natural states) and processes of cell division and growth-will be made possible. The use of soft X rays is not limited to biological studies-many applications are possible in, for example, fusion research, materials science, and astronomy. Such studies have only recently begun in earnest because several difficulties had to be overcome, major among these being the lack (for some purposes) of sufficiently intense sources, and the technological difficulties associated with making efficient optical systems. As is well known, the advent of dedicated synchrotron radiation sources, in particular, has alleviated the first of these difficulties, not just for the soft X-ray region. It is the purpose of this book to consider progress in the second."

This volume contains the full proceedings of the Fourth Advanced Study Institute organised by myself and my colleagues in . * the field of Communication Theory and Allied Subjects. In the first Institute we associated the subject of signal processing in communication with that in control engineering. Then we concentrated on noise and random phenomena by bringing in as well the subject of stochastic calculus. The third time our subject was multi-user communication and associated with it, the important problem of assessing algorithmic complexity. This time we are concerned with the vast increase of computational power that is now available in communication systems processors and controllers. This forces a mathematical, algorithmic and structural approach to the solution of computational requirements and design problems, in contrast to previous heuristic and intuitive methods. We are also concerned with the interactions and trade-offs between the structure, speed, and complexity of a process, and between software and hardware implementations. At the previous Advanced Study Institute in this series, on Multi-User Communications, there was a session on computational complexity, applied particularly to network routing problems. It was the aim of this Institute to expand this topic and to link it with information theory, random processes, pattern analysis, and implementation aspects of communication processors. The first part of these proceedings concentrates on pattern and structure in communications processing. In organising this session I was greatly helped and guided by Professor P. G. Farrell and Professor J. L. Massey.