This book constitutes the proceedings of the 19th International Symposium on Acoustical Imaging at the Ruhr-University Bochum, Germany during April 3 -5, 1991. It was the first time that the symposium was held in Europe after major political changes happened in that area. The freedom to travel for all people from eastern European countries was an obvious reason for the great numbers of sub mitted abstracts and for numerous conference participants. 193 of 239 submitted contributions from 29 countries were accepted for presentation by authors from USA (13%), Canada (2%), Japan (7%), Peoples Republic of China (7%), United Kingdom (4%), France (7%), Italy (3%), Poland (4%), Soviet Union (7%), Germany (28%) and other countries (18%). 283 scientists from 29 countries attended the conference representing the interdisciplinary field between mathematics, physics, engineering and medicine. 151 papers were available for publication in this proceedings covering the topics 1. Mathematics and Physics of Acoustical Imaging 2. Components and Systems 3. Applications in Medicine and Biology 4. Applications in Nondestructive Testing 5. Remote Sensing Applications 6. Industrial Applications A relative large number of contributions on acoustical microscopy was included in the conference program within topics 3 and 4. Also, papers on "non-traditional" acoustical imaging subjects, e. g. on phonon imaging and on remote sensing in the atmosphere, have broadened the scope of the conference. The success and stimulation of the conference and of the papers presented in this volume is owed, of course to the authors and participants.

The 105 theses contained in this book are selected from those whose authors were present at the 20th International Symposium on Acoustical Imaging. held at Southeast University. Nanjing. China. during September 12-14. 1992. It was the first time that the symposium had been held in China. Our efforts to host the conference goes back to the 15th International Symposium on Acoustical Imaging held in Halifax. Canada. in 1986. We are glad that the 20th symposium has been successfully held at last. We are ardent for the symposium not only because we attach much importance to the field of acoustical imaging. but also because we admire the tradition of the serious academic exploration and friendly cooperation of the scholars attending the symposium. The theses in this book are from 21 countries and those by Mr. G. Wade. Takuso Sato. J. F. Greenleaf. K. J. Langenberg. and Wencai Yang are the specially invited papers. These theses cover such important fields of acoustical imaging as follows: 1. Mathematics and physics of acoustical imaging; 2. Components and industry application; 3. Applications in medicine and biology; 4. Applications in nondestructive testing; 5. Applications in geophysics; 6. Underwater acoustical imaging. All these theses reflect the latest progress in theory and technology. We are very grateful to all the authors who have provided these theses.

This book focuses on researching the chime stone, a percussion instrument carved from stone that originated in ancient China. In antiquity, people regarded the chime stone as an important musical instrument because its presence indicated the wealth and status of the tomb owners. In the late Neolithic Age, people discovered the differences between each type of stone and their sound qualities. Chime stone manufacture focused on the timbre of the natural stone, as opposed to both materials and sounding based selection in later periods, which formed a part of making a perfect and delicate chime stone. In the earlier period the chime stone was only a musical instrument for producing rhythmic sound, but as time went by, chime stones gradually became melodic instruments and were played with string, wind, and other percussion instruments in ensemble. The book is divided into 10 chapters. Chapter 1 provides a comprehensive view of existing research, sets out the aims of the present research alongside material sources and methodology, elaborates the theoretical framework of the book, and clarifies terminology in both English and Chinese. A summary of the main chime stone finds of the Yellow River andthe Yangtze River valley areas, together with geographical features of these distributions, is provided in Chapter 2. Chapters 3 to 8 contain an in-depth discussion of the chime stones unearthed from those regions, including classification and typology, shape, manufacture, assemblage and performance of the chime stones as well as the detailed tone measurementand analysis. Chapter 9 examines the acoustic properties of chime stones. Chapter 10 looks at the use and function of chime stones, which includes the role of chime stones in ancient ensembles, cultural context, use in ritual music, and the symbolic meaning of chime stones in ancient China.

SAW devices are widely used in multitude of device concepts mainly in MEMS and communication electronics. As such, SAW based micro sensors, actuators and communication electronic devices are well known applications of SAW technology. For example, SAW based passive micro sensors are capable of measuring physical properties such as temperature, pressure, variation in chemical properties, and SAW based communication devices perform a range of signal processing functions, such as delay lines, filters, resonators, pulse compressors, and convolvers. In recent decades, SAW based low-powered actuators and microfluidic devices have significantly added a new dimension to SAW technology. This book consists of 20 exciting chapters composed by researchers and engineers active in the field of SAW technology, biomedical and other related engineering disciplines. The topics range from basic SAW theory, materials and phenomena to advanced applications such as sensors actuators, and communication systems. As such, in addition to theoretical analysis and numerical modelling such as Finite Element Modelling (FEM) and Finite Difference Methods (FDM) of SAW devices, SAW based actuators and micro motors, and SAW based micro sensors are some of the exciting applications presented in this book. This collection of up-to-date information and research outcomes on SAW technology will be of great interest, not only to all those working in SAW based technology, but also to many more who stand to benefit from an insight into the rich opportunities that this technology has to offer, especially to develop advanced, low-powered biomedical implants and passive communication devices.

Acoustics is a major concern in many long spaces, such as road or railway tunnels, underground/railway stations, corridors, concourses and urban streets. The specific problems of such irregularly shaped spaces, ranging from noise pollution in streets and tunnels to poor speech intelligibility of public address systems in railway stations are not dealt with by classic room acoustic theory.This state-of-the-art exposition of acoustics of long spaces presents the fundamentals of acoustic theory and calculation formulae for long spaces as well as giving guidelines for practical design.

The Chinese made the world's first bronze chime-bells, which they used to perform ritual music, particularly during the Shang and Zhou dynasties (ca. 1700-221 B.C.). Lothar von Falkenhausen's rich and detailed study reconstructs how the music of these bells—the only Bronze Age instruments that can still be played—may have sounded and how it was conceptualized in theoretical terms. His analysis and discussion of the ritual, political, and technical aspects of this music provide a unique window into ancient Chinese culture. This is the first interdisciplinary perspective on recent archaeological finds that have transformed our understanding of ancient Chinese music. Of great significance to the understanding of Chinese culture in its crucial formative stage, it provides a fresh point of departure for exploring later Asian musical history and offers great possibilities for comparisons with music worldwide.

A comprehensive tutorial on ultrasonic motors for practicing engineers, researchers and graduate students. "Ultrasonic Motors: Technologies and Applications" describes the operating mechanism, electromechanical coupling models, optimization design of structural parameters, testing methods, and drive/control techniques of various ultrasonic motors and their applications. Dr. Chunsheng Zhao is a professor at Nanjing University of Aeronautics and Astronautics (NUAA) where he is Director of the Precision Driving Laboratory at NUAA. He is a member of the Chinese Academy of Science, and holds 54 patents in China and published more than 400 papers in the field of piezoelectric ultrasonic motors.

After decades of research activity, Chinese spoken language processing (CSLP) has advanced considerably both in practical technology and theoretical discovery. In this book, the editors provide both an introduction to the field as well as unique research problems with their solutions in various areas of CSLP. The contributions represent pioneering efforts ranging from CSLP principles to technologies and applications, with each chapter encapsulating a single problem and its solutions.A commemorative volume for the 10th anniversary of the international symposium on CSLP in Singapore, this is a valuable reference for established researchers and an excellent introduction for those interested in the area of CSLP.

IMAGE TRACKS AT HALIFAX by L.B. Felsen All living kind much effort spend Some model modes, some model rays, To cope with their environment Some feel that spectra all portrays. Some use their eyes, some use their nose Then there are those who with despatch, To sense where other things repose. Take refuge in the ocean wedge. For one group, nothing's more profound Than to explore the world with sound. If things get messy, randomize. These audio diagnosticians What's partly smooth, determinize. You ponder, is it this or that? Go by the name of acousticians. And wish you were a lowly bat They regularly meet to check Whether their sonogram's on track. The meeting's hosts did treat us well. With images stored in their packs, They let the climate cast its spell. This year they came to Halifax. No weath'ry hope was placed in vain. There they combined with ocean types We were exposed to wind and rain, And each could hear the other's gripes. We glimpsed blue sky through clouds dispersed. A meeting naturally does start But rainy sequence was reversed: Reviewing present state of art. The ocean types would like it wet What we found out is where it's at: Yet they got stuck with sun instead. We cannot hope to match the bat Each confrence has the same refrain: Computer printouts by the reams It has been fun to meet again.