Increasing the noise immunity of complex signal processing systems is the main problem in various areas of signal processing. At the present time there are many books and periodical articles devoted to signal detection, but many important problems remain to be solved. New approaches to complex problems allow us not only to summarize investigations, but also to improve the quality of signal detection in noise. This book is devoted to fundamental problems in the generalized approach to signal processing in noise based on a seemingly abstract idea: the introduction of an additional noise source that does not carry any information about the signal in order to improve the qualitative performance of complex signal processing systems. Theoretical and experimental studies carried out by the author lead to the conclusion that the proposed generalized approach to signal processing in noise allows us to formulate a decision-making rule based on the determi nation of the jointly sufficient statistics of the mean and variance of the likelihood function (or functional). Classical and modern signal detection theories allow us to define only the sufficient statistic of the mean of the likelihood function (or functional). The presence of additional information about the statistical characteristics of the like lihood function (or functional) leads to better-quality signal detection in comparison with the optimal signal detection algorithms of classical and modern theories.

Applied Underwater Acoustics meets the needs of scientists and engineers working in underwater acoustics and graduate students solving problems in, and preparing theses on, topics in underwater acoustics. The book is structured to provide the basis for rapidly assimilating the essential underwater acoustic knowledge base for practical application to daily research and analysis. Each chapter of the book is self-supporting and focuses on a single topic and its relation to underwater acoustics. The chapters start with a brief description of the topic's physical background, necessary definitions, and a short description of the applications, along with a roadmap to the chapter. The subtopics covered within individual subchapters include most frequently used equations that describe the topic. Equations are not derived, rather, assumptions behind equations and limitations on the applications of each equation are emphasized. Figures, tables, and illustrations related to the sub-topic are presented in an easy-to-use manner, and examples on the use of the equations, including appropriate figures and tables are also included. - Provides a complete and up-to-date treatment of all major subjects of underwater acoustics - Presents chapters written by recognized experts in their individual field - Covers the fundamental knowledge scientists and engineers need to solve problems in underwater acoustics - Illuminates, in shorter sub-chapters, the modern applications of underwater acoustics that are described in worked examples - Demands no prior knowledge of underwater acoustics, and the physical principles and mathematics are designed to be readily understood by scientists, engineers, and graduate students of underwater acoustics - Includes a comprehensive list of literature references for each chapter

The 17th International Symposium on Acoustical Imaging was held at Tohoku University, Sendai, Japan, during May 31-June 2, 1988. The symposium was organized by the ultrasonics research group of Tohoku University and the IEEE ijFFC Society, Tokyo Chapter. Of the 128 papers submitted, 88 were presented during the symposium, which comprised 144 researchers from 13 countries. This volume contains 81 papers as the record of the symposium and is clas sified into the following sections: (1) Acoustic Microscopy and its Applications; (2) Non-Destructive Evaluation; (3) Signal Processing of Images; (4) Acoustic Measurements and Physical Acoustics; (5) Medical Ultrasonic Diagnostics; (6) Acoustic Sensors; (7) Acoustic Holography and Tomography; (8) Seismic Exploration; and (9) Imaging Instrumentation and Other Techniques. A number of the papers submitted were associated with medical ultrasonic diagnostics and acoustic microscopy, reflecting a major activity in acousti cal imaging at Tohoku University. Accordingly, two invited talks were focused on this area: acoustic microscopy by Dr. G. A. D. Briggs of the University of Oxford and medical ultrasonics by Prof. M. Tanaka of Tohoku University. In light of the history of research in this field at our university, we are delighted to have had the opportunity to host the 17th symposium.