The most important characteristic of the “world filled with nonlinearity” is the existence of scale interference: disparate space–time scales interfere with each other. Thus, the effects of unknowable scales invade the world that we can observe directly. This leads to various peculiar phenomena such as chaos, critical phenomena, and complex biological phenomena, among others. Conceptual analysis and phenomenology are the keys to describe and understand phenomena that are subject to scale interference, because precise description of unfamiliar phenomena requires precise concepts and their phenomenological description. The book starts with an illustration of conceptual analysis in terms of chaos and randomness, and goes on to explain renormalization group philosophy as an approach to phenomenology. Then, abduction is outlined as a way to express what we have understood about the world. The book concludes with discussions on how we can approach genuinely complex phenomena, including biological phenomena. The main target of this volume is young people who have just started to appreciate the world seriously. The author also wishes the book to be helpful to those who have been observing the world, but who wish to appreciate it afresh from a different angle.

Drawing examples from mathematics, physics, chemistry, biology, engineering, economics, medicine, politics, and sports, this book illustrates how nonlinear dynamics plays a vital role in our world. Examples cover a wide range from the spread and possible control of communicable diseases, to the lack of predictability in long-range weather forecasting, to competition between political groups and nations. After an introductory chapter that explores what it means to be nonlinear, the book covers the mathematical concepts such as limit cycles, fractals, chaos, bifurcations, and solitons, that will be applied throughout the book. Numerous computer simulations and exercises allow students to explore topics in greater depth using the Maple computer algebra system. The mathematical level of the text assumes prior exposure to ordinary differential equations and familiarity with the wave and diffusion equations. No prior knowledge of Maple is assumed. The book may be used at the undergraduate or graduate level to prepare science and engineering students for problems in the "real world", or for self-study by practicing scientists and engineers.

Drawing examples from mathematics, physics, chemistry, biology, engineering, economics, medicine, politics, and sports, this book illustrates how nonlinear dynamics plays a vital role in our world. Examples cover a wide range from the spread and possible control of communicable diseases, to the lack of predictability in long-range weather forecasting, to competition between political groups and nations. After an introductory chapter that explores what it means to be nonlinear, the book covers the mathematical concepts such as limit cycles, fractals, chaos, bifurcations, and solitons, that will be applied throughout the book. Numerous computer simulations and exercises allow students to explore topics in greater depth using the Maple computer algebra system. The mathematical level of the text assumes prior exposure to ordinary differential equations and familiarity with the wave and diffusion equations. No prior knowledge of Maple is assumed. The book may be used at the undergraduate or graduate level to prepare science and engineering students for problems in the "real world", or for self-study by practicing scientists and engineers.

This is a personal story about being involved in the study of nonlinear phenomena for more than half a century. The focus is on the development of ideas and the resulting knowledge. This is the visible part of research, but much is usually hidden. The author describes how the ideas were generated and how an "invisible college" of friends and colleagues has emerged. The presentation is spiced by thoughts about the beauty of science and philosophical considerations on the complex world, where nonlinear interactions play an important role. The book is in some sense a biography but not so much about the personal life of the author -- it is about science and its actors. Based on the author's experience in many European research centres and science policy institutions, it reflects on the development of knowledge in nonlinear dynamics as well as science policy actions over the second half of the 20th century and the first quarter of the 21st century. Graduates and postgraduates interested in the progress of research will find the book particularly engaging.

This festschrift is dedicated to Professor Howell Tong on the occasion of his 65th birthday. With a Foreword written by Professor Peter Whittle, FRS, it celebrates Tong's path-breaking and tireless contributions to nonlinear time series analysis, chaos and statistics, by reprinting 10 selected papers by him and his collaborators, which are interleaved with 17 original reviews, written by 19 international experts. Through these papers and reviews, readers will have an opportunity to share many of the excitements, retrospectively and prospectively, of the relatively new subject of nonlinear time series. Tong has played a leading role in laying the foundation of the subject; his innovative and authoritative contributions are reflected in the review articles in the volume, which describe modern and related developments in the subject, including applications in many major fields such as ecology, economics, finance and others. This volume will be useful to researchers and students interested in the theory and practice of nonlinear time series analysis. Sample Chapter(s). Foreword (68 KB). Chapter 1: Birth of the Threshold Time Series Model (269 KB). Contents: Reflections on Threshold Autoregression (P J Brockwell); The Threshold Approach in Volatility Modelling (W K Li); Dependence and Nonlinearity (M Rosenblatt); Recent Developments on Semiparametric Regression Model Selection (J Gao); Thoughts on the Connections Between Threshold Time Series Models and Dynamical Systems (D B H Cline); Crossing the Bridge Backwards: Some Comments on Early Interdisciplinary Efforts (C D Cutler); On Likelihood Ratio Tests for Threshold Autoregression (K-S Chan & H Tong); An Adaptive Estimation Method for Semiparametric Models and Dimension Reduction (C Leng et al.); On Howell Tong's Contributions to Reliability (M M Ali); and other papers. Readership: Graduate students and researchers in statistics and related fields of ecology, economics and finance.