Positive Feedback in Natural Systems

Positive Feedback in Natural Systems PDF Author: Donald L. DeAngelis
Publisher: Springer Science & Business Media
ISBN: 3642826253
Category : Mathematics
Languages : en
Pages : 292

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Book Description
Cybernetics, a science concerned with understanding how systems are regulated, has reflected the preoccupations of the century in which it was born. Regulation is important in twentieth century society, where both machines and social organizations are complex. Cybernetics focused on and became primarily associated with the homeostasis or stability of system behavior and with the negative feedbacks that stabilize systems. It paid less attention to the processes opposite to negative feedback, the positive feedback processes that act to change systems. We attempt to redress the balance here by illustrating the enormous importance of positive feedbacks in natural systems. In an article in the American Scientist in 1963, Maruyama called for increased attention to this topic, noting that processes of change could occur when a "deviation in anyone component of the system caused deviations in other components that acted back on the first component to reinforce of amplify the initial deviation." The deviation amplification is the result of positive feedback among system components. Maruyama demonstrated by numerous examples that the neglect of such processes was unjustified and suggested that a new branch of cybernetics, "the second cybernetics," be devoted to their study.

Positive Feedback in Natural Systems

Positive Feedback in Natural Systems PDF Author: Donald L. DeAngelis
Publisher: Springer Science & Business Media
ISBN: 3642826253
Category : Mathematics
Languages : en
Pages : 292

Get Book Here

Book Description
Cybernetics, a science concerned with understanding how systems are regulated, has reflected the preoccupations of the century in which it was born. Regulation is important in twentieth century society, where both machines and social organizations are complex. Cybernetics focused on and became primarily associated with the homeostasis or stability of system behavior and with the negative feedbacks that stabilize systems. It paid less attention to the processes opposite to negative feedback, the positive feedback processes that act to change systems. We attempt to redress the balance here by illustrating the enormous importance of positive feedbacks in natural systems. In an article in the American Scientist in 1963, Maruyama called for increased attention to this topic, noting that processes of change could occur when a "deviation in anyone component of the system caused deviations in other components that acted back on the first component to reinforce of amplify the initial deviation." The deviation amplification is the result of positive feedback among system components. Maruyama demonstrated by numerous examples that the neglect of such processes was unjustified and suggested that a new branch of cybernetics, "the second cybernetics," be devoted to their study.

Positive Feedback in Natural Systems

Positive Feedback in Natural Systems PDF Author: Donald Lee DeAngelis
Publisher: Springer Verlag
ISBN: 9780387159423
Category : Science
Languages : en
Pages : 0

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Book Description


Feedback Systems

Feedback Systems PDF Author: Karl Johan Åström
Publisher: Princeton University Press
ISBN: 069121347X
Category : Technology & Engineering
Languages : en
Pages :

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Book Description
The essential introduction to the principles and applications of feedback systems—now fully revised and expanded This textbook covers the mathematics needed to model, analyze, and design feedback systems. Now more user-friendly than ever, this revised and expanded edition of Feedback Systems is a one-volume resource for students and researchers in mathematics and engineering. It has applications across a range of disciplines that utilize feedback in physical, biological, information, and economic systems. Karl Åström and Richard Murray use techniques from physics, computer science, and operations research to introduce control-oriented modeling. They begin with state space tools for analysis and design, including stability of solutions, Lyapunov functions, reachability, state feedback observability, and estimators. The matrix exponential plays a central role in the analysis of linear control systems, allowing a concise development of many of the key concepts for this class of models. Åström and Murray then develop and explain tools in the frequency domain, including transfer functions, Nyquist analysis, PID control, frequency domain design, and robustness. Features a new chapter on design principles and tools, illustrating the types of problems that can be solved using feedback Includes a new chapter on fundamental limits and new material on the Routh-Hurwitz criterion and root locus plots Provides exercises at the end of every chapter Comes with an electronic solutions manual An ideal textbook for undergraduate and graduate students Indispensable for researchers seeking a self-contained resource on control theory

The Earth System

The Earth System PDF Author: Lee R.. Kump
Publisher:
ISBN: 9781292021638
Category : Gaia hypothesis
Languages : en
Pages : 462

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Book Description
For courses in Earth Systems Science offered in departments of Geology, Earth Science, Geography and Environmental Science. The first textbook of its kind that addresses the issues of global change from a true Earth systems perspective, The Earth System offers a solid emphasis on lessons from Earth's history that may guide decision-making in the future. It is more rigorous and quantitative than traditional Earth science books, while remaining appropriate for non-science majors.

Biological Feedback

Biological Feedback PDF Author: Rene Thomas
Publisher: CRC Press
ISBN: 1040280536
Category : Science
Languages : en
Pages : 328

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Book Description
Clearly explaining the logical analysis of biological control phenomena, Biological Feedback answers questions concerning everything from regulation to logic. This rare monograph presents a formal methodology for analyzing the dynamic behavior of complex systems. The easy-to-read text describes a simple logical formalization called "kinetic logic". The reader discovers how this method is used to predict all possible patterns of behavior of which a system is capable. It includes specific conditions required for each pattern. It also explains how to modify an incorrect model in order to account for the observed behavior. The authors give special attention to the two basic types of simple feedback loops: positive and negative. This volume is filled with easy-to-use tables, providing quick reference throughout the book. The subject matter is of great interest to everyone working in molecular genetics and developmental biology. Researchers, immunologists, physical chemists, physicists, electrical engineers, economists, and mathematicians will find this unique text to be an informative, indispensable resource.

Advancing the Science of Climate Change

Advancing the Science of Climate Change PDF Author: National Research Council
Publisher: National Academies Press
ISBN: 0309145880
Category : Science
Languages : en
Pages : 526

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Book Description
Climate change is occurring, is caused largely by human activities, and poses significant risks for-and in many cases is already affecting-a broad range of human and natural systems. The compelling case for these conclusions is provided in Advancing the Science of Climate Change, part of a congressionally requested suite of studies known as America's Climate Choices. While noting that there is always more to learn and that the scientific process is never closed, the book shows that hypotheses about climate change are supported by multiple lines of evidence and have stood firm in the face of serious debate and careful evaluation of alternative explanations. As decision makers respond to these risks, the nation's scientific enterprise can contribute through research that improves understanding of the causes and consequences of climate change and also is useful to decision makers at the local, regional, national, and international levels. The book identifies decisions being made in 12 sectors, ranging from agriculture to transportation, to identify decisions being made in response to climate change. Advancing the Science of Climate Change calls for a single federal entity or program to coordinate a national, multidisciplinary research effort aimed at improving both understanding and responses to climate change. Seven cross-cutting research themes are identified to support this scientific enterprise. In addition, leaders of federal climate research should redouble efforts to deploy a comprehensive climate observing system, improve climate models and other analytical tools, invest in human capital, and improve linkages between research and decisions by forming partnerships with action-oriented programs.

Climate Change

Climate Change PDF Author: The Royal Society
Publisher: National Academies Press
ISBN: 0309302021
Category : Science
Languages : en
Pages : 74

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Book Description
Climate Change: Evidence and Causes is a jointly produced publication of The US National Academy of Sciences and The Royal Society. Written by a UK-US team of leading climate scientists and reviewed by climate scientists and others, the publication is intended as a brief, readable reference document for decision makers, policy makers, educators, and other individuals seeking authoritative information on the some of the questions that continue to be asked. Climate Change makes clear what is well-established and where understanding is still developing. It echoes and builds upon the long history of climate-related work from both national academies, as well as on the newest climate-change assessment from the United Nations' Intergovernmental Panel on Climate Change. It touches on current areas of active debate and ongoing research, such as the link between ocean heat content and the rate of warming.

Environmental Systems

Environmental Systems PDF Author: Robert John Bennett
Publisher: Princeton University Press
ISBN: 1400867258
Category : Social Science
Languages : en
Pages : 637

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Book Description
Here is an indispensable text and reference book for anyone interested in a systems approach to environmental studies. It will be useful not only to geographers but also to ecologists and other environmental scientists; planners; economists and other social scientists; philosophers; and applied mathematicians. Bennett and Chorley's book has a number of broad aims: first, to employ the systems approach to provide an interdisciplinary focus on environmental structures and techniques; second, to use this approach to aid in developing the interfacing of social and economic theory with physical and biological theory; and third, to investigate the implications of this interfacing for human response to current environmental dilemmas, and hence to expose the technological and social bases of values which underlie our use of natural resources. Interpreting the "environment" so as to embrace physical, biological, man-made, social, and economic reality, the authors show that the systems approach provides a powerful vehicle for the statement of environmental situations of ever-growing temporal and spatial magnitude, and for reducing the areas of uncertainty in our increasingly complex decision making arenas. Originally published in 1979. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.

Fundamentals of Natural Computing

Fundamentals of Natural Computing PDF Author: Leandro Nunes de Castro
Publisher: CRC Press
ISBN: 1584886439
Category : Science
Languages : en
Pages : 698

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Book Description
Natural computing brings together nature and computing to develop new computational tools for problem solving; to synthesize natural patterns and behaviors in computers; and to potentially design novel types of computers. Fundamentals of Natural Computing: Basic Concepts, Algorithms, and Applications presents a wide-ranging survey of novel techniques and important applications of nature-based computing. This book presents theoretical and philosophical discussions, pseudocodes for algorithms, and computing paradigms that illustrate how computational techniques can be used to solve complex problems, simulate nature, explain natural phenomena, and possibly allow the development of new computing technologies. The author features a consistent and approachable, textbook-style format that includes lucid figures, tables, real-world examples, and different types of exercises that complement the concepts while encouraging readers to apply the computational tools in each chapter. Building progressively upon core concepts of nature-inspired techniques, the topics include evolutionary computing, neurocomputing, swarm intelligence, immunocomputing, fractal geometry, artificial life, quantum computing, and DNA computing. Fundamentals of Natural Computing is a self-contained introduction and a practical guide to nature-based computational approaches that will find numerous applications in a variety of growing fields including engineering, computer science, biological modeling, and bioinformatics.

Future Ready

Future Ready PDF Author: Steve Morlidge
Publisher: John Wiley & Sons
ISBN: 0470662212
Category : Business & Economics
Languages : en
Pages : 328

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Book Description
The recent crisis in the financial markets has exposed serious flaws in management methods. The failure to anticipate and deal with the consequences of the unfolding collapse has starkly illustrated what many leaders and managers in business have known for years; in most organizations, the process of forecasting is badly broken. For that reason, forecasting business performance tops the list of concerns for CFO's across the globe. It is time to rethink the way businesses organize and run forecasting processes and how they use the insights that they provide to navigate through these turbulent times. This book synthesizes and structures findings from a range of disciplines and over 60 years of the authors combined practical experience. This is presented in the form of a set of simple strategies that any organization can use to master the process of forecasting. The key message of this book is that while no mortal can predict the future, you can take the steps to be ready for it. ’Good enough’ forecasts, wise preparation and the capability to take timely action, will help your organization to create its own future. Written in an engaging and thought provoking style, Future Ready leads the reader to answers to questions such as: What makes a good forecast? What period should a forecast cover? How frequently should it be updated? What information should it contain? What is the best way to produce a forecast? How can you avoid gaming and other forms of data manipulation? How should a forecast be used? How do you ensure that your forecast is reliable? How accurate does it need to be? How should you deal with risk and uncertainty What is the best way to organize a forecast process? Do you need multiple forecasts? What changes should be made to other performance management processes to facilitate good forecasting? Future Ready is an invaluable guide for practicing managers and a source of insight and inspiration to leaders looking for better ways of doing things and to students of the science and craft of management. Praise for Future Ready "Will make a difference to the way you think about forecasting going forward" —Howard Green, Group Controller Unilever PLC "Great analogies and stories are combined with rock solid theory in a language that even the most reading-averse manager will love from page one" —Bjarte Bogsnes, Vice President Performance Management Development at StatoilHydro "A timely addition to the growing research on management planning and performance measurement." —Dr. Charles T. Horngren, Edmund G. Littlefield Professor of Accounting Emeritus Stanford University and author of many standard texts including Cost Accounting: A Managerial Emphasis, Introduction to Management Accounting, and Financial Accounting "In the area of Forecasting, it is the best book in the market." —Fritz Roemer. Leader of Enterprise Performance Executive Advisory Program, the Hackett Group