Selforganization by Nonlinear Irreversible Processes


Book Description

These Proceedings contain invited lectures presented at the third Interna tional Conference on "Irreversible Processes and Dissipative Structures" in Kiihlungsborn (German Democratic Republic) in March, 1985. These con ferences, the first of which was held in Rostock in 1977 and the second in Berlin in 1982, are devoted to the study of irreversible processes far from thermal equilibrium and to the phenomena of selforganization. The meet ing in Kiihlungsborn brought together some 160 mathematicians, physicists, chemists and biologists from 10 countries, who are all interested in the inter disciplinary field of synergetics. The main topics of the conference were basic concepts of selforganization and evolution, such as entropy, instabilities, nucleation, dissipative struc tures, chaos and turbulence. The contributions cover methods from ther modynamics, the theory of dynamic systems, stochastic and statistic theory, the method of Green's functions, the fluctuation-dissipation theorem, etc. Several problems are studied in more detail, e.g., the kinetics of nucleation especially in finite systems, the dynamics of interfaces, reaction-diffusion sys tems, chemical and biochemical pattern formation and information process ing. Further, several contributions are devoted to the development of the concepts of chaos and turbulence. The editors hope that the contributions collected in this volume will pro vide some new information about the field of selforganization, which is in full development now.




Self-Organization in Nonequilibrium Systems


Book Description

Membranes, Dissipative Structures, and Evolution Edited by G. Nicolis & R. Lefever Focuses on the problem of the emergence/maintenance of biological order at successively higher levels of complexity. Covers the spatiotemporal organization of simple biochemical networks; the formation of pluricellular or macromolecular assemblies; the evolution of these structures; and the functions of specific biological structures. Volume 29 in Advances in Chemical Physics Series, I. Prigogine & Stuart A. Rice, Editors. 1975 Theory and Applications of Molecular Paramagnetism Edited by E. A. Boudreaux & L. N. Mulay Comprehensively treats the basic theory of paramagnetic phenomena from both the classical and mechanical vantages. It examines the magnetic behavior of Lanthanide and Actinide elements as well as traditional transition metals. For each class of compounds, appropriate details of descriptive and mathematical theory are given before their applications. 1976 Theory and Aapplications of Molecular Diamagnetism Edited by L. N. Mulay & E. A. Boudreaux An invaluable reference for solving chemical problems in magnetics, magnetochemistry, and related areas where magnetic data are important, such as solid-state physics and optical spectroscopy. 1976







Cooperative Dynamics in Complex Physical Systems


Book Description

Many novel cooperative phenomena found in a variety of systems studied by scientists can be treated using the uniting principles of synergetics. Examples are frustrated and random systems, polymers, spin glasses, neural networks, chemical and biological systems, and fluids. In this book attention is focused on two main problems. First, how local, topological constraints (frustrations) can cause macroscopic cooperative behavior: related ideas initially developed for spin glasses are shown to play key roles also for optimization and the modeling of neural networks. Second, the dynamical constraints that arise from the nonlinear dynamics of the systems: the discussion covers turbulence in fluids, pattern formation, and conventional 1/f noise. The volume will be of interest to anyone wishing to understand the current development of work on complex systems, which is presently one of the most challenging subjects in statistical and condensed matter physics.




The Physics of Structure Formation


Book Description

The formation and evolution of complex dynamical structures is one of the most exciting areas of nonlinear physics. Such pattern formation problems are common in practically all systems involving a large number of interacting components. Here, the basic problem is to understand how competing physical forces can shape stable geometries and to explain why nature prefers just these. Motivation for the intensive study of pattern formation phenomena during the past few years derives from an increasing appreciation of the remarkable diversity of behaviour encountered in nonlinear systems and of universal features shared by entire classes of nonlinear processes. As physics copes with ever more ambi tious problems in pattern formation, summarizing our present state of knowledge becomes a pressing issue. This volume presents an overview of selected topics in this field of current interest. It deals with theoretical models of pattern formation and with simulations that bridge the gap between theory and experiment. The book is a product of the International Symposium on the Physics of Structure Formation, held from October 27 through November 2, 1986, at the Institute for Information Sciences of the University of Tiibingen. The symposium brought together a group of distinguished scientists from various disciplines to exchange ideas about recent advances in pattern formation in the physical sciences, and also to introduce young scientists to the fi




Inside Versus Outside


Book Description

In our daily lives we conceive of our surroundings as an objectively given reality. The world is perceived through our senses, and ~hese provide us, so we believe, with a faithful image of the world. But occ~ipnally we are forced to realize that our senses deceive us, e. g. , by illusions. For a while it was believed that the sensation of color is directly r~lated to the frequency of light waves, until E. Land (the inventor of the polaroid camera) showed in detailed experiments that our perception of, say, a colored spot depends on the colors of its surrounding. On the other hand, we may experience hallucinations or dreams as real. Quite evidently, the relationship between the "world" and our "brain" is intricate. Another strange problem is the way in which we perceive time or the "Now". Psychophysical experiments tell us that the psychological "Now" is an extended period of time in the sense of physics. The situation was made still more puzzling when, in the nineteen-twenties, Heisenberg and others realized that, by observing processes in the microscopic world of electrons and other elementary particles, we strongly interfere with that world. The outcome of experiments - at least in general - can only be predicted statistically. What is the nature ofthis strange relationship between "object" and "observer"? This is another crucial problem of the inside-outside or endo-exo dichotomy.




Limits of Predictability


Book Description

One of the driving forces behind much of modern science and technology is the desire to foresee and thereby control the future. In recent years, however, it has become clear that, even in a deterministic world, there is alimit to the accuracy with which we can predict the future. This book details, in a largely nontechnical style, the extent to which we can predict the future development of various physical, biological and socio-economic processes.




Computational Systems — Natural and Artificial


Book Description

This book contains the invited papers presented at an international sympo sium held at Schloss Elmau, Bavaria (FRG), May 4-9, 1987. Leading experts from neurobiology, medicine, physics, and the computer sciences joined to gether to present and discuss their most recent results. A particular example of the natural computational systems discussed is the visual system of man and animals. A bridge between neural networks and physical systems is provided by spin glass models of neural networks, which were also treated. Concrete realizations of new kinds of devices in microelectronics were among the further topics, as were general problems on the calculation of chaotic orbits. In this way these proceedings present a number of quite recent ap proaches to problems which are of great current interest in fields concerned with computational systems. Bringing together scientists from neurobiology, physics, and the computer sciences has been one of the main aims of the synergetics enterprise, and in particular of its international symposia, from the very beginning. For exam ple, its first meeting held in 1972 at Schloss Elmau included, among others, papers by R. Landauer and J. W. F. Woo on cooperative phenomena in data processing, by W. Reichardt on mechanisms of pattern recognition by the visual system of insects, by B. Julesz on stereoscopic depth perception, and by H. R. Wilson on cooperative phenomena in a homogeneous cortical tissue model. Whole meetings and the corresponding proceedings were devoted to these problems, e. g.




Ambiguity in Mind and Nature


Book Description

Ambiguity in Mind and Nature is the result of cognitive multistability, the phenomenon in which an unchanging stimulus, usually visual, gives rise in the subject to an oscillating perceptual interpretation. The vase/face picture is one of the most famous examples. In this book scientists from many disciplines including physics, biology, psychology, maths and computer science, present recent progress in this fascinating area of cognitive science. Using the phenomenon of multistability as a paradigm they seek to understand how meaning originates in the brain as a consequence of cognitive processes. New advances are achieved by applying concepts such as self-organization, chaos theory and complex systems to the latest results of psychological and neurophysical experiments.




Brain Dynamics


Book Description

This book addresses a large variety of models in mathematical and computational neuroscience. It is written for the experts as well as for graduate students wishing to enter this fascinating field of research. The author studies the behaviour of large neural networks composed of many neurons coupled by spike trains. An analysis of phase locking via sinusoidal couplings leading to various kinds of movement coordination is included.