[PDF] Generic Early Warning Signals For Critical Transitions eBook

Author : Sami A. Houry
Publisher :
Page : pages
File Size : 49,87 MB
Release : 2018
Category :
ISBN :

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Complex systems range from business entities, the human brain, to the climate. These systems have tipping points at which a small perturbation can trigger a critical transition leading to an emergence at an alternate stable state. Although there are differences in the nature of different complex systems, their behaviors exhibit universal characteristics as they near a tipping point. Among such characteristics are the common generic early warning signals that precede critical transitions. The signals include: critical slowing down in which the rate of recovery from perturbations decreases over time; an increase in the variance and skewness of the state variable; an increase in the autocorrelation of the state variable; flickering between different states; and an increase in spatial correlations. The presence of such signals has significant management implications, as the identification of signals prior to the tipping points could allow management to identify intervention points. A review of literature did not identify any applications for the signals in managing undergraduate program student withdrawal at distance universities, hence the research gap. This research assessed the signals through an intensive case study of undergraduate program student withdrawal at a Canadian Distance University by comparing the incidences of the signals among inactive students to the incidences of the signals among graduates. Findings showed support for the signal on the rise in flickering, represented in the increase in the student's non-pass rates prior to withdrawing from a program; moderate support for the signal of critical slowing down, reflected in the longer time a student spends in a course; and moderate support for the signals on increase in autocorrelation, skewness and variance in the grade variable. The research also extended knowledge by investigating whether the emergence of a program withdrawal status is self-similar at the program level and the course level. Findings moderately supported self-similarity as a potential signal. In conclusion, the research into the signals and self-similarity suggests that the signals could be potentially utilized as a predictive management tool. These findings represent the beginnings of future research into the creation of program withdrawal Complexity based models and the possible identification of intervention points.

Author : Marten Scheffer
Publisher : Princeton University Press
Page : 398 pages
File Size : 30,49 MB
Release : 2020-11-10
Category : Science
ISBN : 1400833272

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How do we explain the remarkably abrupt changes that sometimes occur in nature and society--and can we predict why and when they happen? This book offers a comprehensive introduction to critical transitions in complex systems--the radical changes that happen at tipping points when thresholds are passed. Marten Scheffer accessibly describes the dynamical systems theory behind critical transitions, covering catastrophe theory, bifurcations, chaos, and more. He gives examples of critical transitions in lakes, oceans, terrestrial ecosystems, climate, evolution, and human societies. And he demonstrates how to deal with these transitions, offering practical guidance on how to predict tipping points, how to prevent "bad" transitions, and how to promote critical transitions that work for us and not against us. Scheffer shows the time is ripe for understanding and managing critical transitions in the vast and complex systems in which we live. This book can also serve as a textbook and includes a detailed appendix with equations. Provides an accessible introduction to dynamical systems theory Covers critical transitions in lakes, oceans, terrestrial ecosystems, the climate, evolution, and human societies Explains how to predict tipping points Offers strategies for preventing "bad" transitions and triggering "good" ones Features an appendix with equations

Author : Marten Scheffer
Publisher : Springer Science & Business Media
Page : 378 pages
File Size : 41,12 MB
Release : 2013-04-17
Category : Science
ISBN : 1402031548

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Ecology of Shallow Lakes brings together current understanding of the mechanisms that drive the diametrically opposite states of water clarity, shown by the cover paintings, found in many shallow lakes and ponds. It gives an outline of the knowledge gained from field observations, experimental work, and restoration studies, linked by a solid theoretical framework. The book focuses on shallow lakes, but the lucid treatment of plankton dynamics, resuspension, light climate and the role of vegetation is relevant to a much wider range of aquatic systems. The models that are used remain simple and most analyses are graphical rather than algebraic. The text will therefore appeal to students, scientists and policy makers in the field of ecology, fisheries, pollution studies and water management, and also to theoreticans who will benefit from the many real-world examples of topics such as predation and competition theory, bifurcation analysis and catastrophe theory. Perhaps most importantly, the book is a remarkable example of how large field experiments and simple models can catalyze our insight into complex ecosystems. Marten Scheffer wrote this book while at the Institute of Inland Water Management and Waste Treatment, RIZA, Lelystad, The Netherlands. He is currently at the Department of Water Quality Management and Aquatic Ecology of the Wageningen Agricultural University. Reviews `Much rarer are textbooks that so succinctly sum up the state-of-the-art knowledge about a subject that they become instant `bibles'. This book is one of these. It is probably one of the best biological textbooks I have read. Scheffer masterfully pulls all this information together under one cover and presents a coherent account, which will serve as a benchmark for the subject. The reader will not gain any great insight into the breeding biology of pike from this book, nor learn much about dragonflies or newts. They will, however, come to understand the essential nature of shallow lakes or, as the author puts it, `how shallow lakes work'. Overall, this book will be of great interest to practical and theoretical ecologists, students and managers in all fields of biology. All freshwater ecologists should certainly read it.' Simon Harrison in Journal of Ecology, 86 `The book by Scheffer can be seen as a milestone in the recognition of shallow lakes as a research topic in its own right. Scheffer uses three approaches concurrently to unravel the functioning of shallow lakes: 1) statistical analysis of large datasets from a variety of lakes; 2) simple abstract models made up of a few non-linear ordinary differential equations, which he calls `mini-models'; and 3) logical reasoning based on a mixture of results from fieldwork, experiments and models. What is new is that Scheffer links mathematics very nicely with what one feels is a correct description of the functioning of a shallow lake. Employing logical reasoning, Scheffer combines all these sources of knowledge into a general, coherent picture of the functioning of a shallow lake.' Wolf Mooij in Aquatic Ecology, 32

Author : W. Horsthemke
Publisher : Springer Science & Business Media
Page : 322 pages
File Size : 49,67 MB
Release : 2006-09-12
Category : Science
ISBN : 3540368523

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The study of phase transitions is among the most fascinating fields in physics. Originally limited to transition phenomena in equilibrium systems, this field has outgrown its classical confines during the last two decades. The behavior of far from equilibrium systems has received more and more attention and has been an extremely active and productive subject of research for physicists, chemists and biologists. Their studies have brought about a more unified vision of the laws which govern self-organization processes of physico-chemical and biological sys tems. A major achievement has been the extension of the notion of phase transi tion to instabilities which occur only in open nonlinear systems. The notion of phase transition has been proven fruitful in apphcation to nonequilibrium ins- bihties known for about eight decades, like certain hydrodynamic instabilities, as well as in the case of the more recently discovered instabilities in quantum optical systems such as the laser, in chemical systems such as the Belousov-Zhabotinskii reaction and in biological systems. Even outside the realm of natural sciences, this notion is now used in economics and sociology. In this monograph we show that the notion of phase transition can be extend ed even further. It apphes also to a new class of transition phenomena which occur only in nonequilibrium systems subjected to a randomly fluctuating en vironment.

Author : Dietmar Plenz
Publisher : John Wiley & Sons
Page : 734 pages
File Size : 16,72 MB
Release : 2014-04-14
Category : Computers
ISBN : 3527651020

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Neurowissenschaftler suchen nach Antworten auf die Fragen, wie wir lernen und Information speichern, welche Prozesse im Gehirn verantwortlich sind und in welchem Zeitrahmen diese ablaufen. Die Konzepte, die aus der Physik kommen und weiterentwickelt werden, können in Medizin und Soziologie, aber auch in Robotik und Bildanalyse Anwendung finden. Zentrales Thema dieses Buches sind die sogenannten kritischen Phänomene im Gehirn. Diese werden mithilfe mathematischer und physikalischer Modelle beschrieben, mit denen man auch Erdbeben, Waldbrände oder die Ausbreitung von Epidemien modellieren kann. Neuere Erkenntnisse haben ergeben, dass diese selbstgeordneten Instabilitäten auch im Nervensystem auftreten. Dieses Referenzwerk stellt theoretische und experimentelle Befunde internationaler Gehirnforschung vor zeichnet die Perspektiven dieses neuen Forschungsfeldes auf.

Author : Ramesh D. Gulati
Publisher : Springer Science & Business Media
Page : 459 pages
File Size : 22,54 MB
Release : 2007-11-03
Category : Science
ISBN : 1402063997

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This volume comprises the proceedings of the 5th International Symposium on Shallow Lakes, held at Dalfsen, The Netherlands, in June 2005. The theme of the symposium was Shallow Lakes in a Changing World, and it dealt with water-quality issues, such as changes in lake limnology, especially those driven by eutrophication and pollution, increased nutrient loading and productivity, perennial blooms of cyanobacteria and loss of biodiversity.

Author : Yuri Kuznetsov
Publisher : Springer Science & Business Media
Page : 648 pages
File Size : 48,38 MB
Release : 2013-03-09
Category : Mathematics
ISBN : 1475739788

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Providing readers with a solid basis in dynamical systems theory, as well as explicit procedures for application of general mathematical results to particular problems, the focus here is on efficient numerical implementations of the developed techniques. The book is designed for advanced undergraduates or graduates in applied mathematics, as well as for Ph.D. students and researchers in physics, biology, engineering, and economics who use dynamical systems as model tools in their studies. A moderate mathematical background is assumed, and, whenever possible, only elementary mathematical tools are used. This new edition preserves the structure of the first while updating the context to incorporate recent theoretical developments, in particular new and improved numerical methods for bifurcation analysis.

Author : John Guckenheimer
Publisher : Springer Science & Business Media
Page : 475 pages
File Size : 29,73 MB
Release : 2013-11-21
Category : Mathematics
ISBN : 1461211409

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An application of the techniques of dynamical systems and bifurcation theories to the study of nonlinear oscillations. Taking their cue from Poincare, the authors stress the geometrical and topological properties of solutions of differential equations and iterated maps. Numerous exercises, some of which require nontrivial algebraic manipulations and computer work, convey the important analytical underpinnings of problems in dynamical systems and help readers develop an intuitive feel for the properties involved.

Author : Nils Berglund
Publisher : Springer Science & Business Media
Page : 283 pages
File Size : 36,15 MB
Release : 2006-02-07
Category : Mathematics
ISBN : 1846281865

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Stochastic Differential Equations have become increasingly important in modelling complex systems in physics, chemistry, biology, climatology and other fields. This book examines and provides systems for practitioners to use, and provides a number of case studies to show how they can work in practice.

Author : Jean-Pierre Michel
Publisher : Oxford University Press
Page : 1393 pages
File Size : 34,36 MB
Release : 2018
Category : Family & Relationships
ISBN : 0198701594

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The third edition of the definitive international reference book on all aspects of the medical care of older persons will provide every physician involved in the care of older patients with a comprehensive resource on all the clinical problems they are likely to encounter, as well as on related psychological, philosophical, and social issues.