Direct observation— the so-called Black Box theory.
Part II uses the methods developed in Part I to study what is
Meant by “information”, and how it is coded when it passes
Through a mechanism. It applies these methods to various prob-
Lems in biology and tries to show something of the wealth of pos-
Sible applications. It leads into Shannon’s theory; so after reading
This Part the reader will be able to proceed without difficulty to the
Study of Shannon’s own work.
Part III deals with mechanism and information as they are used
In biological systems for regulation and control, both in the inborn
Systems studied in physiology and in the acquired systems studied
In psychology. It shows how hierarchies of such regulators and
Controllers can be built, and how an amplification of regulation is
Thereby made possible. It gives a new and altogether simpler
Account of the principle of ultrastability. It lays the foundation for
A general theory of complex regulating systems, developing fur-
Ther the ideas of Design for a Brain. Thus, on the one hand it pro-
Vides an explanation of the outstanding powers of regulation
Possessed by the brain, and on the other hand it provides the prin-
Ciples by which a designer may build machines of like power.
Though the book is intended to be an easy introduction, it is not
Intended to be merely a chat about cybernetics— it is written for
Those who want to work themselves into it, for those who want to
Achieve an actual working mastery of the subject. It therefore con-
Tains abundant easy exercises, carefully graded, with hints and
Explanatory answers, so that the reader, as he progresses, can test his
Grasp of what he has read, and can exercise his new intellectual mus-
Cles. A few exercises that need a special technique have been marked
thus: *Ex. Their omission will not affect the reader’s progress.
For convenience of reference, the matter has been divided into
Sections; all references are to the section, and as these numbers are
Shown at the top of every page, finding a section is as simple and
Direct as finding a page. The section is shown thus: S.9/14— indi-
Cating the fourteenth section in Chapter 9. Figures, Tables, and
|
|
|
Vi
Exercises have been numbered within their own sections; thus
Fig. 9/14/2 is the second figure in S.9/14. A simple reference, e.g.
Ex. 4, is used for reference within the same section. Whenever a
Word is formally defined it is printed in bold-faced type.
I would like to express my indebtedness to Michael B. Sporn,
Who checked all the Answers. I would also like to take this oppor-
Tunity to express my deep gratitude to the Governors of Barnwood
House and to Dr. G. W. T. H. Fleming for the generous support that
Made these researches possible. Though the book covers many top-
Ics, these are but means; the end has been throughout to make clear
What principles must be followed when one attempts to restore nor-
Mal function to a sick organism that is, as a human patient, of fear-
Ful complexity. It is my faith that the new understanding may lead
To new and effective treatments, for the need is great.
Barnwood House
Gloucester
W. ROSS ASHBY
Vii
CO N TEN TS
CONTENTS
Page
Preface . . . . . . . . . . . . . . . . . . . . . . v
Chapter
WHAT IS NEW . . . . . . . . . . . . . . . . . . 1
The peculiarities of cybernetics . . . . . . . . . . 1
The uses of cybernetics . . . . . . . . . . . . . 4
PART ONE: MECHANISM
CHANGE . . . . . . . . . . . . . . . . . . . . 9
Transformation . . . . . . . . . . . . . . . . 10
Repeated change . . . . . . . . . . . . . . . 16
THE DETERMINATE MACHINE . . . . . . . . . . . 24
Vectors . . . . . . . . . . . . . . . . . . . 30
THE MACHINE WITH INPUT . .
Coupling systems . . . . .
Feedback . . . . . . . .
Independence within a whole
The very large system . . .
.
.
.
.
.
|
|
|
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
42
48
53
55
61
TRANSMISSION OF VARIETY . . . . .
Inversion . . . . . . . . . . .
Transmission from system to system.
Transmission through a channel . .
INCESSANT TRANSMISSION
The Markov chain . .
Entropy. . . . . . .
Noise . . . . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
140
145
151
154
161
165
174
186
PART THREE: REGULATION AND CONTROL
REGULATION IN BIOLOGICAL SYSTEMS . . . . . . 195
Survival. . . . . . . . . . . . . . . . . . . 197
REQUISITE VARIETY
The law. . . . .
Control . . . . .
Some variations .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
202
|
|
|
206
213
216
219
225
231
235
238
240
244
247
251
255
259
265
265
270
271
THE ERROR-CONTROLLED REGULATOR .
The Markovian machine . . . . . .
Markovian regulation . . . . . . .
Determinate regulation. . . . . . .
The power amplifier. . . . . . . .
Games and strategies . . . . . . .
REGULATING THE VERY LARGE SYSTEM
Repetitive disturbance . . . . . . .
Designing the regulator . . . . . .
Quantity of selection . . . . . . .
Selection and machinery . . . . . .
AMPLIFYING REGULATION .
What is an amplifier? . .
Amplification in the brain
Amplifying intelligence .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
STABILITY . . . . . . . . . . . . . . . . . . . 73
Disturbance . . . . . . . . . . . . . . . . . 77
Дата добавления: 2019-11-16; просмотров: 234; Мы поможем в написании вашей работы! |
Мы поможем в написании ваших работ!