The majority of the chapters in this volume represent a series of lectures. that were given at a workshop on quantum transport in ultrasmall electron devices, held at San Miniato, Italy, in March 1987. These have, of course, been extended and updated during the period that has elapsed since the workshop was held, and have been supplemented with additional chapters devoted to the tunneling process in semiconductor quantum-well structures. The aim of this work is to review and present the current understanding in nonequilibrium quantum transport appropriate to semiconductors. Gen­ erally, the field of interest can be categorized as that appropriate to inhomogeneous transport in strong applied fields. These fields are most likely to be strongly varying in both space and time. Most of the literature on quantum transport in semiconductors (or in metallic systems, for that matter) is restricted to the equilibrium approach, in which spectral densities are maintained as semiclassical energy­ conserving delta functions, or perhaps incorporating some form of collision broadening through a Lorentzian shape, and the distribution functions are kept in the equilibrium Fermi-Dirac form. The most familiar field of nonequilibrium transport, at least for the semiconductor world, is that of hot carriers in semiconductors.

The NATO Advanced Study on Waveguide Optoelectronics was held at the Kelvin Conference Centre in Glasgow, Scotland, between 30 July and 10 August 1990. In aliSO students and 15 lecturers attended the ASI. The successof the meeting was due not only to the high quality of the presentations but also to the enthusiasm ofall the participants and their willingness to take part in the discussion and poster sessions. 1990 was also the year in which Glasgow was the European City of Culture. This resulted in interesting diversions during the middle weekend of the school and also made the meeting probably the first NATO ASI to share accommodation with the Bolshoi Opera and Ballet who gave memorable performances as partof the City's celebrations. This volume is, however, intended to be more than merely a record of presentations at the NATO meeting. The authors have written their material so as to be approachable by a first­ degree graduate with some background in optoelectronics. The principal materials considered are the III-V semiconductors, lithium niobate and silica. Recent developments towards optoelectronic integration in semiconductors, developments in devices fabricated in doped silica and doped lithium niobate, and developments in all-optical switching networks are highlighted. The role of reduced dimensional structures is examined in some detail.

Solar Energy Technology deals with all aspects of solar energy systems. The fundamentals of predicting avail- ability; economic appraisal strategies; specific collector sub-systems, including a proven analytical procedure for predicting performance; and analyses of solar energy systems from dryers to greenhouses, passive solar buildings to water pumps, are covered in depth. Researchers and technologists need to have an insight into the challenges implementation entails, and this book presents practical constraints, operational considerations, and the latest research results. The book should be of great interest to students as well as professionals undertaking feasibility studies, development and implementation, technical assistance, and training assignments. Political action and pressure groups will also find the text useful for developing energy policies.

This book emerged from lecture notes of a course taught in the second year to students of Computer Science at the Federal Institute of Tech­ nology, Zurich. The topic of hardware design plays a relatively minor role in Compu­ ter Science curricula at many universities. Most courses concentrate on the various aspects of theory, software, and of information sys­ tems. Students therefore obtain few opportunities to deal with con­ crete engineering problems and physical devices. We consider this as rather unfortunate, particularly for technical universities. As a result, we observe a growing gap between interest in and understanding of design issues involving not only software but also hardware and inter­ faces. This is regrettable at a time when new and advanced solutions to many problems are often crucially influenced by recent hardware de­ velopments, at a time when the engineer needs to be competent in both software and hardware issues in order to fmd an optimally inte­ grated, competitive solution. It turns out that the hesitation of many students in Computer Science to take an active interest in hardware - his or her daily tool! - does not only stem from a preference of "clean", abstract concepts with a corre­ sponding distaste for dealing with concrete components, construction techniques, and the "dirty" realities inflicted by nature, but also stems from the lack of a bridge between the two realms.

Neural Networks presents concepts of neural-network models and techniques of parallel distributed processing in a three-step approach: - A brief overview of the neural structure of the brain and the history of neural-network modeling introduces to associative memory, preceptrons, feature-sensitive networks, learning strategies, and practical applications. - The second part covers subjects like statistical physics of spin glasses, the mean-field theory of the Hopfield model, and the "space of interactions" approach to the storage capacity of neural networks. - The final part discusses nine programs with practical demonstrations of neural-network models. The software and source code in C are on a 3 1/2" MS-DOS diskette can be run with Microsoft, Borland, Turbo-C, or compatible compilers.