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236:. This is caused by a phase shift around any loop. Due to these phase shifts the feedback signal of some frequencies can ultimately become in phase with the input signal and thus turn into positive feedback, creating a runaway condition. Even before the point where the phase shift becomes 180 degrees, stability of the negative feedback loop will become compromised, leading to increasing under- and overshoot following a disturbance. This problem is often dealt with by attenuating or changing the phase of the problematic frequencies in a design step called compensation. Unless the system naturally has sufficient damping, many negative feedback systems have
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1804:, and planet temperature. As incoming solar radiation increases, planet temperature increases. As the temperature increases, the amount of plant life that can grow increases. This plant life can then make products such as sulfur which produce more cloud cover. An increase in cloud cover leads to higher
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The concept of 'feedback', so simple and natural in certain elementary cases, becomes artificial and of little use when the interconnections between the parts become more complex...Such complex systems cannot be treated as an interlaced set of more or less independent feedback circuits, but only as a
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If a mixture of the reactants and products exists at equilibrium in a sealed container and nitrogen gas is added to this system, then the equilibrium will shift toward the product side in response. If the temperature is raised, then the equilibrium will shift toward the reactant side which, since the
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is feedback in which the system responds so as to increase the magnitude of any particular perturbation, resulting in amplification of the original signal instead of stabilization. Any system in which there is positive feedback together with a gain greater than one will result in a runaway situation.
1643:. Glucocorticoids not only perform their respective functions throughout the body but also negatively affect the release of further stimulating secretions of both the hypothalamus and the pituitary gland, effectively reducing the output of glucocorticoids once a sufficient amount has been released.
129:
Blood glucose levels are maintained at a constant level in the body by a negative feedback mechanism. When the blood glucose level is too high, the pancreas secretes insulin and when the level is too low, the pancreas then secretes glucagon. The flat line shown represents the homeostatic set point.
1354:
The idealized model of an operational amplifier assumes that the gain is infinite, the input impedance is infinite, output resistance is zero, and input offset currents and voltages are zero. Such an ideal amplifier draws no current from the resistor divider. Ignoring dynamics (transient effects
57:
in a manner that tends to reduce the fluctuations in the output, whether caused by changes in the input or by other disturbances. A classic example of negative feedback is a heating system thermostat — when the temperature gets high enough, the heater is turned OFF. When the temperature gets too
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at low frequencies, decreasing gradually at higher frequencies. In addition, it exhibits a finite input impedance and a non-zero output impedance. Although practical op-amps are not ideal, the model of an ideal op-amp often suffices to understand circuit operation at low enough frequencies. As
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whole. For understanding the general principles of dynamic systems, therefore, the concept of feedback is inadequate in itself. What is important is that complex systems, richly cross-connected internally, have complex behaviors, and that these behaviors can be goal-seeking in complex patterns.
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In a simple feedback system a specific physical quantity is being controlled, and control is brought about by making an actual comparison of this quantity with its desired value and utilizing the difference to reduce the error observed. Such a system is self-correcting in the sense that any
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In many physical and biological systems, qualitatively different influences can oppose each other. For example, in biochemistry, one set of chemicals drives the system in a given direction, whereas another set of chemicals drives it in an opposing direction. If one or both of these opposing
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refers to the sign of the multiplier in mathematical models for feedback. In delta notation, −Δoutput is added to or mixed into the input. In multivariate systems, vectors help to illustrate how several influences can both partially complement and partially oppose each other.
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For hormone secretion regulated by the negative feedback loop: when gland X releases hormone X, this stimulates target cells to release hormone Y. When there is an excess of hormone Y, gland X "senses" this and inhibits its release of hormone X. As shown in the figure, most
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1741:"There is a belief current in many countries and elevated to the rank of an official article of faith in the United States that free competition is itself a homeostatic process... Unfortunately the evidence, such as it is, is against this simple-minded theory."
65:— is when a trend is positively reinforced, creating amplification, such as the squealing "feedback" loop that can occur when a mic is brought too close to a speaker which is amplifying the very sounds the mic is picking up, or the runaway heating and ultimate
1359:), the infinite gain of the ideal op-amp means this feedback circuit drives the voltage difference between the two op-amp inputs to zero. Consequently, the voltage gain of the circuit in the diagram, assuming an ideal op amp, is the reciprocal of feedback
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is extremely large, a small differential input signal would drive the output of the amplifier to one rail or the other in the absence of negative feedback. A simple example of the use of feedback is the op-amp voltage amplifier shown in the figure.
3264:
Jickells, T. D.; An, Z. S.; Andersen, K. K.; Baker, A. R.; Bergametti, G.; Brooks, N.; Cao, J. J.; Boyd, P. W.; Duce, R. A.; Hunter, K. A.; Kawahata, H. (2005). "Global Iron
Connections Between Desert Dust, Ocean Biogeochemistry, and Climate".
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came up with the idea of using negative feedback in electronic amplifiers in 1927, submitted a patent application in 1928, and detailed its use in his paper of 1934, where he defined negative feedback as a type of coupling that
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pointed out that, while it may clash with definitions that require a "materially evident" connection, "the exact definition of feedback is nowhere important". Ashby pointed out the limitations of the concept of "feedback":
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256:(circa 1600) using expansion and contraction of columns of mercury in response to temperature changes were used in negative feedback systems to control vents in furnaces, maintaining a steady internal temperature.
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585:). The regulator signal is derived from a weighted sum of the error signal, integral of the error signal, and derivative of the error signal. The weights of the respective components depend on the application.
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1815:. As planet temperature increases, more water vapor is produced, creating more clouds. The clouds then block incoming solar radiation, lowering the temperature of the planet. This interaction produces less
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of
Alexandria in the 3rd century BCE. Self-regulating mechanisms have existed since antiquity, and were used to maintain a constant level in the reservoirs of water clocks as early as 200 BCE.
107:, and also within living organisms, and can be seen in many other fields from chemistry and economics to physical systems such as the climate. General negative feedback systems are studied in
2359:
Giannini, Alessandra; Biasutti, Michela; Verstraete, Michel M. (2008-12-01). "A climate model-based review of drought in the Sahel: Desertification, the re-greening and climate change".
1934:
helped to formalize the concepts of feedback control, defining feedback in general as "the chain of the transmission and return of information", and negative feedback as the case when:
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according to its interpretation of the error in the status of the system. This error may be introduced by a variety of possible disturbances or 'upsets', some slow and some rapid. The
1702:
Self-organization is the capability of certain systems "of organizing their own behavior or structure". There are many possible factors contributing to this capacity, and most often
3324:
Giannini, Alessandra; Biasutti, Michela; Verstraete, Michel M. (2008). "A climate model-based review of drought in the Sahel: Desertification, the re-greening and climate change".
1926:
All purposeful behavior may be considered to require negative feed-back. If a goal is to be attained, some signals from the goal are necessary at some time to direct the behavior.
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There are many advantages to feedback in amplifiers. In design, the type of feedback and amount of feedback are carefully selected to weigh and optimize these various benefits.
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might arise from fluctuations in the amplifier output due to noise and nonlinearity (distortion) within this amplifier, or from other noise sources such as power supplies.
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discussed in the previous section, the feedback circuit stabilizes the closed-loop gain and desensitizes the output to fluctuations generated inside the amplifier itself.
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Negative feedback loops also play an integral role in maintaining the atmospheric balance in various systems on Earth. One such feedback system is the interaction between
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of an electronic amplifier. Friis and Jensen described this action as "positive feedback" and made passing mention of a contrasting "negative feed-back action" in 1924.
1732:, because mismatches between them feed back into the decision-making of suppliers and demanders of goods, altering prices and thereby reducing any discrepancy. However
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and therefore less cloud cover. The cycle then repeats in a negative feedback loop. In this way, negative feedback loops in the environment have a stabilizing effect.
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1018:>> 1. This expression shows that a gain greater than one requires β < 1. Because the approximate gain 1/β is independent of the open-loop gain
3107:
Charlson, Robert J.; Lovelock, James E.; Andreae, Meinrat O.; Warren, Stephen G. (1987). "Oceanic phytoplankton, atmospheric sulphur, cloud albedo and climate".
1808:, or surface reflectivity, of the Earth. As albedo increases, however, the amount of solar radiation decreases. This, in turn, affects the rest of the cycle.
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the forward path may not be strictly unilateral, the feedback path is usually bilateral, and the input and output coupling networks are often complicated.
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In this framework, the physical form of a signal may undergo multiple transformations. For example, a change in weather may cause a disturbance to the
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318:, minimises the effect of manufacturing variations in component parameters, and compensates for changes in characteristics due to temperature change.
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It increases circuit stability: that is, the gain remains stable though there are variations in ambient temperature, frequency and signal amplitude.
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in 1868 described "component motions" associated with these governors that lead to a decrease in a disturbance or the amplitude of an oscillation.
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and a unilateral feedback block has significant limitations. For methods of analysis that do not make these idealizations, see the article
1280:{\displaystyle {\text{Error signal}}=I-\beta O=I\left(1-\beta {\frac {O}{I}}\right)={\frac {I}{1+\beta A}}-{\frac {\beta D}{1+\beta A}}\ .}
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in 1927, and granted a patent in 1937 (US Patent 2,102,671) "a continuation of application Serial No. 298,155, filed August 8, 1928 ...").
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Operational amplifier circuits typically employ negative feedback to get a predictable transfer function. Since the open-loop gain of an
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to refer to the reduction in difference between the desired and actual behavior of a system. In a psychology context, on the other hand,
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754:{\displaystyle \mathrm {MV(t)} =K_{p}\left(\,{e(t)}+{\frac {1}{T_{i}}}\int _{0}^{t}{e(\tau )}\,{d\tau }+T_{d}{\frac {d}{dt}}e(t)\right)}
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278:(1788), negative feedback is used to maintain a near-constant speed of an engine, irrespective of the load or fuel-supply conditions.
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1463:{\displaystyle V_{\text{out}}={\frac {R_{\text{1}}+R_{\text{2}}}{R_{\text{1}}}}V_{\text{in}}\!={\frac {1}{\beta }}V_{\text{in}}\,}
1026:(for example, due to manufacturing variations between units, or temperature effects upon components), provided only that the gain
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The information fed back to the control center tends to oppose the departure of the controlled from the controlling quantity...
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and the physical, and biological sciences, common terms for the points around which the system gravitates include: attractors,
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A simple negative feedback system is descriptive, for example, of some electronic amplifiers. The feedback is negative if the
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1034:) is often called the 'desensitivity factor', and in the broader context of feedback effects that include other matters like
856:"The patent is 52 pages long plus 35 pages of figures. The first 43 pages amount to a small treatise on feedback amplifiers!"
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1588:) use negative feedback. Examples of this are numerous, from the regulating of body temperature, to the regulating of blood
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in a constant phase to a reference signal. In many implementations the generated waveform is the output, but when used as a
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in which just the right amount of correction is applied with optimum timing, can be very stable, accurate, and responsive.
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The notion of economic equilibrium being maintained in this fashion by market forces has also been questioned by numerous
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285:(1866), power assistance is applied to the rudder with a feedback loop, to maintain the direction set by the steersman.
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A feedback voltage amplifier using an op amp with finite gain but infinite input impedances and zero output impedance.
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provided by a furnace (an 'effector') to counter the initial weather-related disturbance in heat input to the house.
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Although the diagram illustrates the principles of the negative feedback amplifier, modeling a real amplifier as a
531:) to reduce the gap between the measurement and the required value. The regulator modifies the input to the system
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1596:, if negative feedback fails, the glucose levels in the blood may begin to rise dramatically, thus resulting in
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cold, the heat is turned back ON. In each case the "feedback" generated by the thermostat "negates" the trend.
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at the amplifier input is sometimes called the "error signal". According to the diagram, the error signal is:
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2005:
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While the view of feedback as any "circularity of action" helped to keep the theory simple and consistent,
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in such systems can range from a simple 'on-off' control to a more complex processing of the error signal.
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which shows that the feedback reduces the effect of the disturbance by the 'improvement factor' (1+β
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Error controlled regulation is typically carried out using a
Proportional-Integral-Derivative Controller (
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104:
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Scott
Camazine; Jean-Louis Deneubourg; Nigel R Franks; James Sneyd; Guy Theraulaz; Eric Bonabeau (2003).
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subsequently generalized the idea of negative feedback to cover any goal-seeking or purposeful behavior.
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2197:
Herold, David M.; Greller, Martin M. (1977). "Research Notes. Feedback: The
Definition of a Construct".
1982:
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metaphor of economic theory (1776), reactions to price movements provide a feedback mechanism to match
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A basic and common example of a negative feedback system in the environment is the interaction among
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92:, negative feedback generally promotes stability. Negative feedback tends to promote a settling to
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radio receiver, the error feedback voltage serves as the demodulated output signal. If there is a
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are government programs that are intended to work as negative feedback to dampen fluctuations in
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to the opposite side of the reaction in order to reduce a stress. For example, in the reaction
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The operational amplifier was originally developed as a building block for the construction of
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3642:. Cambridge, Massachusetts: The Technology Press; New York: John Wiley & Sons, Inc., 1948.
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1534:. Similar control mechanisms are used in heating and cooling systems, such as those involving
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the gain of the amplifier, in the process greatly increasing its stability and bandwidth.
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is identified as a possible contributor. However, negative feedback also can play a role.
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levels. The disruption of feedback loops can lead to undesirable results: in the case of
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Negative feedback amplifier with external disturbance. The feedback is negative if β
300:, is compared to a set value, and any error is reduced by negative feedback to the input.
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3160:"Amplified Arctic climate change: What does surface albedo feedback have to do with it?"
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Between Human and
Machine : Feedback, Control, and Computing before Cybernetics
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30:
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Nyquist and Bode built on Black's work to develop a theory of amplifier stability.
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From this expression, it can be seen that a large 'improvement factor' (or a large
1004:{\displaystyle {\frac {O}{I}}={\frac {A}{1+\beta A}}\approx {\frac {1}{\beta }}\ ,}
913:
881:
Harmonic, phase, amplitude, and frequency distortions are all reduced considerably.
507:). Using a negative feedback loop, a measurement of some variable (for example, a
156:
89:
3697:
Science and Policy in
Natural Resource Management: Understanding System Complexity
1811:
Cloud cover, and in turn planet albedo and temperature, is also influenced by the
3725:
3695:
3428:
3390:
3065:
3052:
3038:
2831:
2402:
Bechhoefer, John (2005). "Feedback for
Physicists: A Tutorial Essay On Control".
2124:
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that identify stable feedback systems, including amplifiers and control systems.
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1999:
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1639:. In turn, ACTH directs the adrenal cortex to secrete glucocorticoids, such as
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897:
558:). This quantity, then, is converted by the thermostat (a 'comparator') into an
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3604:"Karl Kupfmuller, 1928: an early time-domain, closed-loop, stability criterion"
2964:
Psychomythics: Sources of
Artifacts and Misconceptions in Scientific Psychology
2499:
2002: – Transdisciplinary field concerned with regulatory and purposive systems
1827:
Negative feedback as a control technique may be seen in the refinements of the
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2433:
2266:
deviations from the desired performance are used to produce corrective action.
1871:
1855:
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or float valve uses negative feedback to control the water level in a cistern.
1022:, the feedback is said to 'desensitize' the closed-loop gain to variations in
462:
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between the generated waveform and the phase comparator, the device acts as a
346:
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2862:(The Circuits and Filters Handbook, 3rd ed.). CRC Press. pp. 16–2.
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523:) to estimate an operational error in system status, which is then used by a
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3603:
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1956:
To reduce confusion, later authors have suggested alternative terms such as
1863:
1832:
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1335:, but is now used almost universally in all kinds of applications including
1302:
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889:
413:
350:
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35:
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2017: – Graphical method of determining the stability of a dynamical system
888:
Though negative feedback has many advantages, amplifiers with feedback can
2163:
2070:
221:
of the feedback – attractive versus aversive, or praise versus criticism.
3367:
Breedveld, Peter C (2004). "Port-based modeling of mechatronic systems".
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1867:
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54:
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2046: – Time behavior of a system controlled by Heaviside step functions
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reverse reaction is endothermic, will partially reduce the temperature.
229:
Both positive and negative feedback require a feedback loop to operate.
3669:
The Fifth
Discipline: The Art and Practice of the Learning Organization
3639:
Cybernetics: Or Control and Communication in the Animal and the Machine
3455:
3025:
Cybernetics: Or Control and Communication in the Animal and the Machine
1608:
1589:
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The feedback sets the overall (closed-loop) amplifier gain at a value:
354:
241:
152:
2210:
378:), a negative feedback loop is used to repeatedly correct accumulated
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3128:
1805:
297:
268:
3404:
2178:
Business Dynamics: Systems Thinking and Modeling for a Complex World
1502:
3093:
Sixth Assessment Report (AR6), Working Group I, IPCC, 2021, p. 96.
1124:{\displaystyle O={\frac {AI}{1+\beta A}}+{\frac {D}{1+\beta A}}\ ,}
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1501:
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It reduces non-linear distortion, that is, it has higher fidelity.
444:
427:
304:
293:
138:
124:
29:
3498:
Friis, H. T.; Jensen, A. G. (1924). "High Frequency Amplifiers".
2833:
Design with operational amplifiers and analog integrated circuits
2581:"Figure 11-4: Classical single input, single output control loop"
1889:" was well established by the 1920s, in reference to a means of
1874:
patented a form of governor in 1788 to control the speed of his
1636:
3769:
416:, feedback enables various measures (e.g. body temperature, or
2951:, Fifth Edition, Boston: Hill Companies, Inc. 1999. page 1058.
2523:
CA Desoer (August 1984). "In Memoriam: Harold Stephen Black".
1572:
Some biological systems exhibit negative feedback such as the
1522:. In modern engineering, negative feedback loops are found in
487:
that result in the desired system output despite disturbances
3712:
Balancing or negative feedback counteracts and opposes change
3405:"Tierie, Gerrit. Cornelis Drebbel. Amsterdam: HJ Paris, 1932"
2306:
William Y. Svrcek; Donald P. Mahoney; Brent R. Young (2013).
2150:
Arkalgud Ramaprasad (1983). "On The Definition of Feedback".
2080:. Chapman & Hall Ltd.; Internet (1999). pp. 219–243.
389:(1932), feedback is used to maintain a generated alternating
2035: – Feedback loop that increases an initial small effect
1728:
asserts that the market pricing mechanism operates to match
1030:
is sufficiently large. In this context, the factor (1+β
186:
states, eigenstates/eigenfunctions, equilibrium points, and
19:
For use of criticism and punishment to modify behavior, see
2023: – Control system whose input is independent of output
232:
However, negative feedback systems can still be subject to
3623:
Rosenblueth, Arturo, Norbert Wiener, and Julian Bigelow. "
3209:"Cloud Feedbacks in the Climate System: A Critical Review"
1912:
system and a feedback system stability criterion in 1928.
1514:
An example of the use of negative feedback control is the
2654:(2nd ed.). Cambridge University Press. p. 447.
2614:
Basic Electronics: Devices, Circuits, and IT Fundamentals
2552:
Basic electronics: Devices, circuits and its fundamentals
1862:
were used to regulate the distance and pressure between
574:
control valves and an ignitor) ultimately to change the
148:
influences are non-linear, equilibrium point(s) result.
3571:"Chapter 3: The electronic negative feedback amplifier"
2743:
Linear Control Systems: For Punjab Technical University
2010:
Pages displaying short descriptions of redirect targets
1850:
Negative feedback was implemented in the 17th century.
130:
The sinusoidal line represents the blood glucose level.
3724:
Carver, Charles S.; Scheier, Michael F. (2001-05-07).
2888:"§6.3.4 Linear amplifiers with operational amplifiers"
2129:. Baltimore, MD, USA: Johns Hopkins University Press.
1655:
can also exhibit negative feedback in accordance with
205:
Some authors, in particular with respect to modelling
2481:"Electrical engineering hall of fame: Harold S Black"
1372:
1162:
1058:
947:
864:
Advantages of negative voltage feedback in amplifiers
805:
773:
597:
96:, and reduces the effects of perturbations. Negative
550:) that is monitored by a thermometer as a change in
53:
of the output of a system, process, or mechanism is
4347:
4321:
4033:
3909:
3873:
3803:
3577:. Institution of Electrical Engineers. pp. 70
2681:
Electronic Circuits: Analysis simulation and design
2312:(3rd ed.). John Wiley & Sons. p. 57.
2281:
Process Control: Concepts Dynamics And Applications
1568:
Control of endocrine hormones by negative feedback.
103:Negative feedback is widely used in mechanical and
3666:
2252:
1651:Closed systems containing substances undergoing a
1462:
1279:
1123:
1003:
818:
786:
753:
588:Mathematically, the regulator signal is given by:
420:level) to be maintained within a desired range by
3759:biology online: answers to your biology questions
2739:"§5.3.3 Effect of feedback on disturbance signal"
2548:"§6.3 Advantages of negative feedback amplifiers"
2093:"§6.1 Homeostasis depends upon negative feedback"
1990: – Gaining awareness of biological processes
1435:
931:The figure shows a simplified block diagram of a
2449:"U.S. Patent 2,102,671: Wave Translation System"
2224:Sudheer S Bhagade; Govind Das Nageshwar (2011).
1792:) or weaken (negative feedbacks) global warming.
844:The negative feedback amplifier was invented by
2772:(2nd ed.). Cengage Learning. p. 642.
2769:Microelectronic Circuits: Analysis & Design
1949:
1936:
1924:
1615:negative feedback inhibition loop, such as the
2799:Circuit Analysis and Feedback Amplifier Theory
2304:For example, input and load disturbances. See
1908:published papers on a negative-feedback-based
546:input to a house (as an example of the system
3781:
2341:. University of Exeter: Physics and astronomy
2091:Robert E. Ricklefs; Gary Leon Miller (2000).
1996: – Branch of engineering and mathematics
1858:incubators and ovens in the early 1600s, and
503:to minimize the effect of a disturbance (say
495:One use of feedback is to make a system (say
296:or position of an output, as determined by a
8:
3627:." Philosophy of science 10.1 (1943): 18-24.
3066:"The Study of Earth as an Integrated System"
2071:"Chapter 12: The error-controlled regulator"
878:It modifies the input and output impedances.
562:error in status compared to the 'set point'
3700:. Cambridge University Press. p. 205.
3694:Helen E. Allison; Richard J. Hobbs (2006).
3564:
3562:
2892:The Design of High Performance Mechatronics
2881:
2879:
2651:The Design of CMOS Radio Frequency Circuits
2616:. PHI Learning Pvt. Ltd. pp. 193–194.
2474:
2472:
1518:control of water level (see diagram), or a
1049:is included, the amplifier output becomes:
3915:
3788:
3774:
3766:
3575:A history of control engineering 1930-1955
3463:Proceedings of the Royal Society of London
3000:. Princeton University Press. pp. 15
2008: – Feedback related to climate change
1584:. Many biological processes (e.g., in the
1014:where the approximate value assumes β
554:(as an example of an 'essential variable'
69:of a nuclear reactor which has a positive
3474:
3380:
3232:
3183:
2710:Basic Electronics: Devices, Circuits and
2518:
2516:
2423:
2118:
2116:
1846:is an early example of negative feedback.
1474:A real op-amp has a high but finite gain
1459:
1453:
1439:
1429:
1417:
1406:
1393:
1386:
1377:
1371:
1298:) tends to keep this error signal small.
1245:
1221:
1203:
1163:
1161:
1094:
1065:
1057:
985:
961:
948:
946:
810:
804:
778:
772:
719:
713:
698:
697:
683:
677:
672:
660:
651:
634:
633:
622:
598:
596:
570:(containing a 'controller' that commands
2994:"Chapter 2: How self-organization works"
2230:. PHI Learning Pvt. Ltd. pp. 6, 9.
1563:
1322:
918:
466:
3653:Circuit Theory of Linear Noisy Networks
3369:Mathematics and Computers in Simulation
2998:Self-organization in biological systems
2854:The four possible op-amp configurations
2309:A Real-Time Approach to Process Control
2064:
2062:
2060:
2056:
3761:. Biology-Online.org. 30 January 2020.
3328:. Climate Change and Desertification.
3076:from the original on November 2, 2016.
2850:David G Nair; Sergio B Franco (2009).
2554:. PHI Learning Pvt. Ltd. pp. 193
2525:IEEE Transactions on Automatic Control
2363:. Climate Change and Desertification.
2284:. PHI Learning Pvt. Ltd. p. 222.
1303:unilateral forward amplification block
3651:Hermann A Haus and Richard B. Adler,
2795:"Chapter 13: General feedback theory"
1629:corticotropin-releasing hormone (CRH)
479:so the monitored essential variables
449:Basic error-controlled regulator loop
71:temperature coefficient of reactivity
16:Reuse of output to stabilize a system
7:
4397:
3673:. New York: Doubleday. p. 424.
2860:Fundamentals of Circuits and Filters
4339:Systems theory in political science
3097:from the original on July 21, 2022.
2824:See, for example, Figure 1.4, p. 7
3727:On the Self-Regulation of Behavior
3546:10.1002/j.1538-7305.1934.tb00652.x
3512:10.1002/j.1538-7305.1924.tb01354.x
2479:James E Brittain (February 2011).
2259:. Addison-Wesley Pub. Co. p.
1637:adrenocorticotropic hormone (ACTH)
1319:Operational amplifier applications
608:
602:
599:
14:
2716:. PHI Learning Pvt. p. 194.
1918:Early researchers in the area of
80:tends to lead to instability via
4396:
4384:
4373:
4372:
3527:"Stabilized Feedback Amplifiers"
2967:. Psychology Press. pp. 95
2886:G. Schitter; A. Rankers (2014).
2704:Santiram Kal (14 January 2009).
2339:Feedback and temperature control
875:It increases bandwidth slightly.
143:Feedback loops in the human body
3625:Behavior, purpose and teleology
3346:10.1016/j.gloplacha.2008.05.004
2585:Intuitive Analog Circuit Design
2381:10.1016/j.gloplacha.2008.05.004
566:, and subsequently used by the
61:The opposite tendency — called
4329:Systems theory in anthropology
3730:. Cambridge University Press.
3433:. Cambridge University Press.
2683:. Prentice Hall. p. 671.
2255:Principles of Feedback Control
1313:Operational amplifier circuits
884:Noise is reduced considerably.
743:
737:
693:
687:
644:
638:
611:
605:
475:adjusts the input to a system
1:
4334:Systems theory in archaeology
3611:IEEE Control Systems Magazine
3500:Bell System Technical Journal
3454:Maxwell, James Clerk (1868).
2836:(3rd ed.). McGraw-Hill.
2199:Academy of Management Journal
483:are held to set-point values
310:, negative feedback flattens
3525:Black, H.S. (January 1934).
3391:10.1016/j.matcom.2003.11.002
3207:Stephens, Graeme L. (2005).
3164:Geophysical Research Letters
2921:Op Amp Applications Handbook
2801:. CRC Press. pp. 13–1.
2447:Black, Harold (1937-12-21).
2227:Process Dynamics and Control
2029: – Psychological theory
1653:reversible chemical reaction
1042:, the 'improvement factor'.
369:digital-to-analog converters
261:invisible hand of the market
155:, this process (in general,
3755:"Physiological Homeostasis"
3326:Global and Planetary Change
2745:. Pearson Education India.
2361:Global and Planetary Change
2335:"Types of feedback control"
2078:Introduction to cybernetics
2015:Nyquist stability criterion
1856:thermostatically controlled
1307:Negative feedback amplifier
933:negative feedback amplifier
910:Nyquist stability criterion
840:Negative feedback amplifier
834:Negative feedback amplifier
519:from a required value (the
441:Error-controlled regulation
109:control systems engineering
4461:
2894:. IOS Press. p. 499.
2500:10.1109/jproc.2010.2090997
1691:
1553:
1491:
1316:
837:
452:
167:, the more common term is
159:) is often referred to as
122:, and planet temperature.
18:
4368:
3966:
3918:
3830:Coupled human–environment
3427:Hills, Richard L (1996).
2961:William R. Uttal (2014).
2858:. In Wai-Kai Chen (ed.).
2434:10.1103/revmodphys.77.783
2404:Reviews of Modern Physics
2251:Charles H. Wilts (1960).
2180:McGraw Hill/Irwin, 2000.
2123:David A. Mindell (2002).
2099:. Macmillan. p. 92.
2027:Perceptual control theory
1786:effects of climate change
1556:Counterregulatory hormone
3158:Winton, Michael (2006).
2947:Raven, PH; Johnson, GB.
2766:Muhammad Rashid (2010).
2706:"§6.3.2 Noise Reduction"
2675:Norbert A Malik (1995).
2533:10.1109/tac.1984.1103645
1972:in place of "negative".
1657:Le Chatelier's principle
1633:anterior pituitary gland
896:. They may even exhibit
436:Detailed implementations
4163:Charles A. S. Hall
3665:Peter M. Senge (1990).
3569:Stuart Bennett (1993).
3287:10.1126/science.1105959
2637:Marc T Thompson, p. 309
2610:"§6.3.1 Gain stability"
2488:Proceedings of the IEEE
2006:Climate change feedback
371:(particularly for high
4083:Ludwig von Bertalanffy
3487:– via Wikimedia.
3476:10.1098/rspl.1867.0055
3053:Steady State Economics
3039:The Alchemy of Finance
2923:. Newnes. pp. 12
2915:Walter G Jung (2005).
2830:Sergio Franco (2002).
2527:. AC-29 (8): 673–674.
2333:Charles D H Williams.
2069:W. Ross Ashby (1957).
1954:
1940:
1928:
1910:automatic gain control
1847:
1793:
1569:
1511:
1488:Mechanical engineering
1464:
1328:
1281:
1145:The difference signal
1125:
1005:
928:
820:
788:
755:
492:
450:
432:
331:mathematical functions
327:operational amplifiers
144:
131:
105:electronic engineering
39:
4360:Principia Cybernetica
4073:Anthony Stafford Beer
3943:Sociotechnical system
2793:Wai-Kai Chen (2005).
2648:Thomas H Lee (2004).
2608:Santiram Kal (2009).
2579:Marc Thomson (2006).
2546:Santiram Kal (2009).
2509:on November 29, 2014.
2164:10.1002/bs.3830280103
1983:Asymptotic gain model
1860:centrifugal governors
1841:
1783:
1776:Environmental Science
1763:steady-state theorist
1716:automatic stabilisers
1567:
1505:
1465:
1326:
1282:
1126:
1006:
922:
892:. See the article on
821:
819:{\displaystyle T_{d}}
789:
787:{\displaystyle T_{i}}
756:
470:
448:
431:
276:centrifugal governors
142:
128:
33:
21:performance appraisal
4223:Mihajlo D. Mesarovic
4198:Edward Norton Lorenz
4153:Jay Wright Forrester
3958:World-systems theory
3933:Earth system science
3185:10.1029/2005GL025244
2677:"Improvement Factor"
2021:Open-loop controller
1970:discrepancy-reducing
1930:Cybernetics pioneer
1895:Harold Stephen Black
1788:can either enhance (
1759:ecological economist
1726:Mainstream economics
1661:chemical equilibrium
1631:, which directs the
1611:are controlled by a
1594:blood glucose levels
1483:Areas of application
1370:
1160:
1056:
1036:electrical impedance
945:
846:Harold Stephen Black
803:
771:
595:
407:frequency multiplier
329:is used to generate
4098:Kenneth E. Boulding
3602:C. Bissell (2006).
3534:Bell System Tech. J
3430:Power From the Wind
3338:2008GPC....64..119G
3279:2005Sci...308...67J
3234:10.1175/JCLI-3243.1
3225:2005JCli...18..237S
3176:2006GeoRL..33.3701W
3121:1987Natur.326..655C
2416:2005RvMP...77..783B
2373:2008GPC....64..119G
2039:Stability criterion
1880:James Clerk Maxwell
1768:, who was with the
1750:economists such as
1498:Control engineering
1138:). The disturbance
1045:If the disturbance
682:
455:Control engineering
254:Mercury thermostats
135:General description
49:) occurs when some
4228:James Grier Miller
4183:Faina M. Kirillova
4143:Heinz von Foerster
4133:Edsger W. Dijkstra
4093:Alexander Bogdanov
4078:Richard E. Bellman
4053:William Ross Ashby
3213:Journal of Climate
2826:Ideal op amp model
2152:Behavioral Science
1848:
1813:hydrological cycle
1794:
1790:positive feedbacks
1570:
1520:pressure regulator
1512:
1460:
1329:
1277:
1121:
1001:
929:
816:
784:
751:
668:
493:
451:
433:
382:during conversion.
380:quantization error
325:, feedback around
312:frequency response
145:
132:
82:exponential growth
47:balancing feedback
40:
4435:Signal processing
4412:
4411:
4293:Manuela M. Veloso
4208:Humberto Maturana
4148:Stephanie Forrest
4118:C. West Churchman
4043:Russell L. Ackoff
4029:
4028:
3901:Positive feedback
3896:Negative feedback
3680:978-0-385-26094-7
3655:, MIT Press, 1959
3115:(6114): 655–661.
3089:Technical Summary
2917:"Noise gain (NG)"
2737:SK Bhattacharya.
2456:www.eepatents.com
2278:SK Singh (2010).
2033:Positive feedback
1891:boosting the gain
1852:Cornelius Drebbel
1844:fly-ball governor
1730:supply and demand
1704:positive feedback
1694:Self-organization
1688:Self-organization
1456:
1447:
1432:
1423:
1420:
1409:
1396:
1380:
1357:propagation delay
1273:
1269:
1240:
1211:
1166:
1117:
1113:
1089:
997:
993:
980:
956:
906:Bell Laboratories
850:Bell Laboratories
732:
666:
403:frequency divider
387:phase locked loop
365:analog-to-digital
226:positive feedback
78:positive feedback
63:positive feedback
43:Negative feedback
4452:
4400:
4399:
4388:
4376:
4375:
4288:Francisco Varela
4020:Systems thinking
3953:Urban metabolism
3916:
3790:
3783:
3776:
3767:
3762:
3742:
3741:
3721:
3715:
3714:
3691:
3685:
3684:
3672:
3662:
3656:
3649:
3643:
3634:
3628:
3621:
3615:
3614:
3608:
3599:
3593:
3592:
3566:
3557:
3556:
3554:
3552:
3531:
3522:
3516:
3515:
3495:
3489:
3488:
3478:
3460:
3451:
3445:
3444:
3424:
3418:
3417:
3415:
3414:
3409:
3401:
3395:
3394:
3384:
3364:
3358:
3357:
3321:
3315:
3314:
3261:
3255:
3254:
3236:
3204:
3198:
3197:
3187:
3155:
3149:
3148:
3129:10.1038/326655a0
3104:
3098:
3084:
3078:
3077:
3062:
3056:
3048:
3042:
3034:
3028:
3022:
3016:
3015:
2989:
2983:
2982:
2958:
2952:
2945:
2939:
2938:
2912:
2906:
2905:
2883:
2874:
2873:
2847:
2822:
2816:
2815:
2790:
2784:
2783:
2763:
2757:
2756:
2734:
2728:
2727:
2701:
2695:
2694:
2672:
2666:
2665:
2645:
2639:
2634:
2628:
2627:
2605:
2599:
2598:
2576:
2570:
2569:
2543:
2537:
2536:
2520:
2511:
2510:
2508:
2502:. Archived from
2485:
2476:
2467:
2466:
2464:
2458:. Archived from
2453:
2444:
2438:
2437:
2427:
2399:
2393:
2392:
2356:
2350:
2349:
2347:
2346:
2330:
2324:
2323:
2302:
2296:
2295:
2275:
2269:
2268:
2258:
2248:
2242:
2241:
2221:
2215:
2214:
2194:
2188:
2176:John D.Sterman,
2174:
2168:
2167:
2147:
2141:
2140:
2120:
2111:
2110:
2088:
2082:
2081:
2075:
2066:
2011:
1800:, plant growth,
1659:which shift the
1619:secreted by the
1536:air conditioners
1524:engine governors
1469:
1467:
1466:
1461:
1458:
1457:
1454:
1448:
1440:
1434:
1433:
1430:
1424:
1422:
1421:
1418:
1412:
1411:
1410:
1407:
1398:
1397:
1394:
1387:
1382:
1381:
1378:
1361:voltage division
1333:analog computers
1286:
1284:
1283:
1278:
1271:
1270:
1268:
1254:
1246:
1241:
1239:
1222:
1217:
1213:
1212:
1204:
1167:
1164:
1130:
1128:
1127:
1122:
1115:
1114:
1112:
1095:
1090:
1088:
1074:
1066:
1010:
1008:
1007:
1002:
995:
994:
986:
981:
979:
962:
957:
949:
825:
823:
822:
817:
815:
814:
793:
791:
790:
785:
783:
782:
760:
758:
757:
752:
750:
746:
733:
731:
720:
718:
717:
705:
696:
681:
676:
667:
665:
664:
652:
647:
627:
626:
614:
509:process variable
323:analog computing
238:low pass filters
207:business systems
90:chaotic behavior
4460:
4459:
4455:
4454:
4453:
4451:
4450:
4449:
4440:Analog circuits
4415:
4414:
4413:
4408:
4364:
4343:
4317:
4258:Anatol Rapoport
4243:Talcott Parsons
4218:Donella Meadows
4193:Allenna Leonard
4113:Mary Cartwright
4108:Kathleen Carley
4068:Gregory Bateson
4063:Béla H. Bánáthy
4025:
3962:
3911:
3905:
3891:Limiting factor
3886:Leverage points
3869:
3807:
3799:
3797:Systems science
3794:
3753:
3750:
3745:
3738:
3723:
3722:
3718:
3708:
3693:
3692:
3688:
3681:
3664:
3663:
3659:
3650:
3646:
3636:Norbert Wiener
3635:
3631:
3622:
3618:
3613:: 115–116, 126.
3606:
3601:
3600:
3596:
3589:
3568:
3567:
3560:
3550:
3548:
3529:
3524:
3523:
3519:
3497:
3496:
3492:
3458:
3453:
3452:
3448:
3441:
3426:
3425:
3421:
3412:
3410:
3407:
3403:
3402:
3398:
3382:10.1.1.108.9830
3366:
3365:
3361:
3323:
3322:
3318:
3273:(5718): 67–71.
3263:
3262:
3258:
3206:
3205:
3201:
3157:
3156:
3152:
3106:
3105:
3101:
3085:
3081:
3064:
3063:
3059:
3049:
3045:
3036:Goeroge Soros,
3035:
3031:
3023:
3019:
3012:
2991:
2990:
2986:
2979:
2960:
2959:
2955:
2946:
2942:
2935:
2914:
2913:
2909:
2902:
2885:
2884:
2877:
2870:
2849:
2844:
2829:
2823:
2819:
2809:
2792:
2791:
2787:
2780:
2765:
2764:
2760:
2753:
2736:
2735:
2731:
2724:
2703:
2702:
2698:
2691:
2674:
2673:
2669:
2662:
2647:
2646:
2642:
2635:
2631:
2624:
2607:
2606:
2602:
2595:
2578:
2577:
2573:
2566:
2545:
2544:
2540:
2522:
2521:
2514:
2506:
2483:
2478:
2477:
2470:
2462:
2451:
2446:
2445:
2441:
2425:10.1.1.124.7043
2401:
2400:
2396:
2358:
2357:
2353:
2344:
2342:
2332:
2331:
2327:
2320:
2305:
2303:
2299:
2292:
2277:
2276:
2272:
2250:
2249:
2245:
2238:
2223:
2222:
2218:
2196:
2195:
2191:
2175:
2171:
2149:
2148:
2144:
2137:
2122:
2121:
2114:
2107:
2090:
2089:
2085:
2073:
2068:
2067:
2058:
2054:
2049:
2009:
1978:
1962:self-correcting
1906:Karl Küpfmüller
1825:
1802:solar radiation
1778:
1736:wrote in 1948:
1712:
1700:
1692:Main articles:
1690:
1678:
1674:
1670:
1649:
1617:glucocorticoids
1580:regulation and
1562:
1552:
1500:
1494:Control systems
1490:
1485:
1449:
1425:
1413:
1402:
1389:
1388:
1373:
1368:
1367:
1341:control systems
1321:
1315:
1255:
1247:
1226:
1193:
1189:
1158:
1157:
1099:
1075:
1067:
1054:
1053:
966:
943:
942:
842:
836:
828:derivative time
806:
801:
800:
774:
769:
768:
724:
709:
656:
632:
628:
618:
593:
592:
501:self-regulating
465:
443:
438:
347:differentiation
290:servomechanisms
283:steering engine
250:
137:
116:solar radiation
38:AB is negative.
28:
17:
12:
11:
5:
4458:
4456:
4448:
4447:
4442:
4437:
4432:
4427:
4425:Control theory
4417:
4416:
4410:
4409:
4407:
4406:
4394:
4382:
4369:
4366:
4365:
4363:
4362:
4357:
4351:
4349:
4345:
4344:
4342:
4341:
4336:
4331:
4325:
4323:
4319:
4318:
4316:
4315:
4313:Anthony Wilden
4310:
4308:Jennifer Wilby
4305:
4303:Norbert Wiener
4300:
4295:
4290:
4285:
4280:
4275:
4273:Claude Shannon
4270:
4265:
4260:
4255:
4250:
4248:Ilya Prigogine
4245:
4240:
4238:Howard T. Odum
4235:
4233:Radhika Nagpal
4230:
4225:
4220:
4215:
4210:
4205:
4203:Niklas Luhmann
4200:
4195:
4190:
4185:
4180:
4175:
4170:
4165:
4160:
4155:
4150:
4145:
4140:
4135:
4130:
4128:George Dantzig
4125:
4123:Manfred Clynes
4120:
4115:
4110:
4105:
4100:
4095:
4090:
4088:Margaret Boden
4085:
4080:
4075:
4070:
4065:
4060:
4055:
4050:
4048:Victor Aladjev
4045:
4039:
4037:
4031:
4030:
4027:
4026:
4024:
4023:
4013:
4008:
4003:
3998:
3993:
3988:
3983:
3978:
3973:
3967:
3964:
3963:
3961:
3960:
3955:
3950:
3945:
3940:
3938:Living systems
3935:
3930:
3925:
3923:Control theory
3919:
3913:
3907:
3906:
3904:
3903:
3898:
3893:
3888:
3883:
3877:
3875:
3871:
3870:
3868:
3867:
3862:
3857:
3852:
3847:
3842:
3837:
3832:
3827:
3822:
3817:
3811:
3809:
3801:
3800:
3795:
3793:
3792:
3785:
3778:
3770:
3764:
3763:
3749:
3748:External links
3746:
3744:
3743:
3736:
3716:
3706:
3686:
3679:
3657:
3644:
3629:
3616:
3594:
3587:
3558:
3517:
3506:(2): 181–205.
3490:
3456:"On Governors"
3446:
3439:
3419:
3396:
3359:
3332:(3): 119–128.
3316:
3256:
3219:(2): 237–273.
3199:
3150:
3099:
3079:
3072:. NASA. 2016.
3057:
3043:
3029:
3017:
3010:
2984:
2977:
2953:
2940:
2933:
2907:
2900:
2875:
2868:
2852:"Figure 16.2:
2843:978-0078028168
2842:
2817:
2807:
2785:
2778:
2758:
2751:
2729:
2722:
2696:
2689:
2667:
2660:
2640:
2629:
2622:
2600:
2593:
2571:
2564:
2538:
2512:
2494:(2): 351–353.
2468:
2465:on 2014-10-06.
2439:
2410:(3): 783–835.
2394:
2367:(3): 119–128.
2351:
2325:
2318:
2297:
2290:
2270:
2243:
2236:
2216:
2205:(1): 142–147.
2189:
2169:
2142:
2135:
2112:
2105:
2083:
2055:
2053:
2050:
2048:
2047:
2041:
2036:
2030:
2024:
2018:
2012:
2003:
1997:
1994:Control theory
1991:
1985:
1979:
1977:
1974:
1932:Norbert Wiener
1831:introduced by
1824:
1821:
1777:
1774:
1772:in 1988–1994.
1744:
1743:
1734:Norbert Wiener
1714:In economics,
1711:
1708:
1689:
1686:
1681:
1680:
1676:
1672:
1668:
1648:
1645:
1621:adrenal cortex
1582:erythropoiesis
1578:blood pressure
1551:
1548:
1528:fuel injection
1489:
1486:
1484:
1481:
1472:
1471:
1452:
1446:
1443:
1438:
1428:
1416:
1405:
1401:
1392:
1385:
1376:
1363:ratio β:
1339:equipment and
1317:Main article:
1314:
1311:
1288:
1287:
1276:
1267:
1264:
1261:
1258:
1253:
1250:
1244:
1238:
1235:
1232:
1229:
1225:
1220:
1216:
1210:
1207:
1202:
1199:
1196:
1192:
1188:
1185:
1182:
1179:
1176:
1173:
1170:
1132:
1131:
1120:
1111:
1108:
1105:
1102:
1098:
1093:
1087:
1084:
1081:
1078:
1073:
1070:
1064:
1061:
1012:
1011:
1000:
992:
989:
984:
978:
975:
972:
969:
965:
960:
955:
952:
886:
885:
882:
879:
876:
873:
870:
858:
857:
838:Main article:
835:
832:
831:
830:
813:
809:
798:
781:
777:
762:
761:
749:
745:
742:
739:
736:
730:
727:
723:
716:
712:
708:
704:
701:
695:
692:
689:
686:
680:
675:
671:
663:
659:
655:
650:
646:
643:
640:
637:
631:
625:
621:
617:
613:
610:
607:
604:
601:
583:PID controller
442:
439:
437:
434:
426:
425:
410:
383:
358:
319:
301:
286:
279:
272:
257:
249:
246:
217:refers to the
195:control theory
136:
133:
98:feedback loops
15:
13:
10:
9:
6:
4:
3:
2:
4457:
4446:
4443:
4441:
4438:
4436:
4433:
4431:
4428:
4426:
4423:
4422:
4420:
4405:
4404:
4395:
4393:
4392:
4387:
4383:
4381:
4380:
4371:
4370:
4367:
4361:
4358:
4356:
4353:
4352:
4350:
4348:Organizations
4346:
4340:
4337:
4335:
4332:
4330:
4327:
4326:
4324:
4320:
4314:
4311:
4309:
4306:
4304:
4301:
4299:
4298:Kevin Warwick
4296:
4294:
4291:
4289:
4286:
4284:
4281:
4279:
4276:
4274:
4271:
4269:
4266:
4264:
4261:
4259:
4256:
4254:
4251:
4249:
4246:
4244:
4241:
4239:
4236:
4234:
4231:
4229:
4226:
4224:
4221:
4219:
4216:
4214:
4213:Margaret Mead
4211:
4209:
4206:
4204:
4201:
4199:
4196:
4194:
4191:
4189:
4186:
4184:
4181:
4179:
4176:
4174:
4173:Lydia Kavraki
4171:
4169:
4166:
4164:
4161:
4159:
4158:Barbara Grosz
4156:
4154:
4151:
4149:
4146:
4144:
4141:
4139:
4136:
4134:
4131:
4129:
4126:
4124:
4121:
4119:
4116:
4114:
4111:
4109:
4106:
4104:
4101:
4099:
4096:
4094:
4091:
4089:
4086:
4084:
4081:
4079:
4076:
4074:
4071:
4069:
4066:
4064:
4061:
4059:
4058:Ruzena Bajcsy
4056:
4054:
4051:
4049:
4046:
4044:
4041:
4040:
4038:
4036:
4032:
4021:
4017:
4014:
4012:
4009:
4007:
4004:
4002:
3999:
3997:
3994:
3992:
3989:
3987:
3984:
3982:
3979:
3977:
3974:
3972:
3969:
3968:
3965:
3959:
3956:
3954:
3951:
3949:
3946:
3944:
3941:
3939:
3936:
3934:
3931:
3929:
3926:
3924:
3921:
3920:
3917:
3914:
3908:
3902:
3899:
3897:
3894:
3892:
3889:
3887:
3884:
3882:
3881:Doubling time
3879:
3878:
3876:
3872:
3866:
3863:
3861:
3858:
3856:
3853:
3851:
3848:
3846:
3843:
3841:
3838:
3836:
3833:
3831:
3828:
3826:
3823:
3821:
3818:
3816:
3813:
3812:
3810:
3806:
3802:
3798:
3791:
3786:
3784:
3779:
3777:
3772:
3771:
3768:
3760:
3756:
3752:
3751:
3747:
3739:
3737:9780521000994
3733:
3729:
3728:
3720:
3717:
3713:
3709:
3707:9781139458603
3703:
3699:
3698:
3690:
3687:
3682:
3676:
3671:
3670:
3661:
3658:
3654:
3648:
3645:
3641:
3640:
3633:
3630:
3626:
3620:
3617:
3612:
3605:
3598:
3595:
3590:
3588:9780863412806
3584:
3580:
3576:
3572:
3565:
3563:
3559:
3547:
3543:
3539:
3535:
3528:
3521:
3518:
3513:
3509:
3505:
3501:
3494:
3491:
3486:
3482:
3477:
3472:
3468:
3464:
3457:
3450:
3447:
3442:
3440:9780521566865
3436:
3432:
3431:
3423:
3420:
3406:
3400:
3397:
3392:
3388:
3383:
3378:
3375:(2): 99–128.
3374:
3370:
3363:
3360:
3355:
3351:
3347:
3343:
3339:
3335:
3331:
3327:
3320:
3317:
3312:
3308:
3304:
3300:
3296:
3292:
3288:
3284:
3280:
3276:
3272:
3268:
3260:
3257:
3252:
3248:
3244:
3240:
3235:
3230:
3226:
3222:
3218:
3214:
3210:
3203:
3200:
3195:
3191:
3186:
3181:
3177:
3173:
3170:(3): L03701.
3169:
3165:
3161:
3154:
3151:
3146:
3142:
3138:
3134:
3130:
3126:
3122:
3118:
3114:
3110:
3103:
3100:
3096:
3092:
3090:
3083:
3080:
3075:
3071:
3067:
3061:
3058:
3055:
3054:
3050:Herman Daly,
3047:
3044:
3041:
3040:
3033:
3030:
3026:
3021:
3018:
3013:
3011:9780691116242
3007:
3003:
2999:
2995:
2988:
2985:
2980:
2978:9781135623722
2974:
2970:
2966:
2965:
2957:
2954:
2950:
2944:
2941:
2936:
2934:9780750678445
2930:
2926:
2922:
2918:
2911:
2908:
2903:
2901:9781614993681
2897:
2893:
2889:
2882:
2880:
2876:
2871:
2869:9781420058888
2865:
2861:
2857:
2855:
2845:
2839:
2835:
2834:
2827:
2821:
2818:
2814:
2810:
2808:9781420037272
2804:
2800:
2796:
2789:
2786:
2781:
2779:9780495667728
2775:
2771:
2770:
2762:
2759:
2754:
2752:9788131759523
2748:
2744:
2740:
2733:
2730:
2725:
2723:9788120319523
2719:
2715:
2711:
2707:
2700:
2697:
2692:
2690:9780023749100
2686:
2682:
2678:
2671:
2668:
2663:
2661:9780521835398
2657:
2653:
2652:
2644:
2641:
2638:
2633:
2630:
2625:
2623:9788120319523
2619:
2615:
2611:
2604:
2601:
2596:
2594:9780080478753
2590:
2586:
2582:
2575:
2572:
2567:
2565:9788120319523
2561:
2557:
2553:
2549:
2542:
2539:
2534:
2530:
2526:
2519:
2517:
2513:
2505:
2501:
2497:
2493:
2489:
2482:
2475:
2473:
2469:
2461:
2457:
2450:
2443:
2440:
2435:
2431:
2426:
2421:
2417:
2413:
2409:
2405:
2398:
2395:
2390:
2386:
2382:
2378:
2374:
2370:
2366:
2362:
2355:
2352:
2340:
2336:
2329:
2326:
2321:
2319:9781118684733
2315:
2311:
2310:
2301:
2298:
2293:
2291:9788120336780
2287:
2283:
2282:
2274:
2271:
2267:
2262:
2257:
2256:
2247:
2244:
2239:
2237:9788120344051
2233:
2229:
2228:
2220:
2217:
2212:
2208:
2204:
2200:
2193:
2190:
2187:
2186:9780072389159
2183:
2179:
2173:
2170:
2165:
2161:
2157:
2153:
2146:
2143:
2138:
2136:9780801868955
2132:
2128:
2127:
2119:
2117:
2113:
2108:
2106:9780716728290
2102:
2098:
2094:
2087:
2084:
2079:
2072:
2065:
2063:
2061:
2057:
2051:
2045:
2044:Step response
2042:
2040:
2037:
2034:
2031:
2028:
2025:
2022:
2019:
2016:
2013:
2007:
2004:
2001:
1998:
1995:
1992:
1989:
1986:
1984:
1981:
1980:
1975:
1973:
1971:
1967:
1963:
1959:
1953:
1948:
1945:
1939:
1935:
1933:
1927:
1923:
1921:
1916:
1913:
1911:
1907:
1903:
1901:
1896:
1892:
1888:
1883:
1881:
1877:
1873:
1869:
1865:
1861:
1857:
1853:
1845:
1840:
1836:
1834:
1830:
1822:
1820:
1818:
1814:
1809:
1807:
1803:
1799:
1791:
1787:
1782:
1775:
1773:
1771:
1767:
1764:
1760:
1756:
1753:
1749:
1742:
1739:
1738:
1737:
1735:
1731:
1727:
1723:
1721:
1717:
1709:
1707:
1705:
1699:
1695:
1687:
1685:
1666:
1665:
1664:
1662:
1658:
1654:
1646:
1644:
1642:
1638:
1634:
1630:
1626:
1622:
1618:
1614:
1610:
1607:
1601:
1599:
1595:
1591:
1587:
1586:human anatomy
1583:
1579:
1575:
1566:
1561:
1557:
1549:
1547:
1545:
1541:
1540:refrigerators
1537:
1533:
1529:
1525:
1521:
1517:
1509:
1504:
1499:
1495:
1487:
1482:
1480:
1477:
1450:
1444:
1441:
1436:
1426:
1414:
1403:
1399:
1390:
1383:
1374:
1366:
1365:
1364:
1362:
1358:
1352:
1349:
1344:
1342:
1338:
1334:
1325:
1320:
1312:
1310:
1308:
1304:
1299:
1297:
1293:
1274:
1265:
1262:
1259:
1256:
1251:
1248:
1242:
1236:
1233:
1230:
1227:
1223:
1218:
1214:
1208:
1205:
1200:
1197:
1194:
1190:
1186:
1183:
1180:
1177:
1174:
1171:
1168:
1156:
1155:
1154:
1152:
1148:
1143:
1141:
1137:
1118:
1109:
1106:
1103:
1100:
1096:
1091:
1085:
1082:
1079:
1076:
1071:
1068:
1062:
1059:
1052:
1051:
1050:
1048:
1043:
1041:
1037:
1033:
1029:
1025:
1021:
1017:
998:
990:
987:
982:
976:
973:
970:
967:
963:
958:
953:
950:
941:
940:
939:
936:
934:
927: >0.
926:
921:
917:
915:
911:
908:proposed the
907:
903:
902:Harry Nyquist
899:
895:
894:step response
891:
883:
880:
877:
874:
871:
868:
867:
866:
865:
861:
855:
854:
853:
851:
847:
841:
833:
829:
811:
807:
799:
797:
796:integral time
779:
775:
767:
766:
765:
747:
740:
734:
728:
725:
721:
714:
710:
706:
702:
699:
690:
684:
678:
673:
669:
661:
657:
653:
648:
641:
635:
629:
623:
619:
615:
591:
590:
589:
586:
584:
579:
577:
573:
569:
565:
561:
557:
553:
549:
545:
540:
538:
534:
530:
526:
522:
518:
514:
510:
506:
502:
498:
490:
486:
482:
478:
474:
469:
464:
460:
456:
447:
440:
435:
430:
423:
419:
415:
411:
408:
404:
400:
396:
392:
388:
384:
381:
377:
374:
370:
366:
363:
359:
356:
352:
348:
344:
340:
336:
332:
328:
324:
320:
317:
313:
309:
306:
302:
299:
295:
291:
287:
284:
280:
277:
273:
270:
266:
262:
258:
255:
252:
251:
247:
245:
243:
239:
235:
230:
227:
224:In contrast,
222:
220:
216:
212:
208:
203:
200:
196:
191:
189:
185:
181:
177:
172:
170:
166:
163:; whereas in
162:
158:
154:
149:
141:
134:
127:
123:
121:
117:
112:
110:
106:
101:
99:
95:
91:
87:
83:
79:
74:
72:
68:
64:
59:
56:
52:
48:
44:
37:
32:
26:
25:reinforcement
22:
4401:
4389:
4377:
4322:Applications
4278:Katia Sycara
4178:James J. Kay
4168:Mike Jackson
4103:Murray Bowen
4001:Pharmacology
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1965:
1961:
1958:degenerative
1957:
1955:
1950:
1941:
1937:
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1914:
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1876:steam engine
1849:
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1757:and leading
1755:George Soros
1745:
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1602:
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1532:carburettors
1530:systems and
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1165:Error signal
1150:
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4268:Peter Senge
4263:John Seddon
4253:Qian Xuesen
4188:George Klir
3991:Engineering
3928:Cybernetics
3910:Theoretical
3860:Recommender
3850:Multi-agent
3845:Information
3540:(1): 1–18.
3469:: 270–283.
2158:(1): 4–13.
2000:Cybernetics
1988:Biofeedback
1920:cybernetics
1829:water clock
1817:water vapor
1798:cloud cover
1766:Herman Daly
1679:+ 92 kJ/mol
1635:to secrete
1613:physiologic
1560:Homeostasis
898:instability
552:temperature
521:'set point'
459:Homeostasis
422:homeostatic
418:blood sugar
395:demodulator
362:delta-sigma
343:integration
339:subtraction
180:mathematics
176:engineering
169:equilibrium
161:homeostasis
157:biochemical
120:cloud cover
94:equilibrium
86:oscillation
4419:Categories
4283:Eric Trist
4138:Fred Emery
4035:Scientists
4011:Psychology
4006:Philosophy
3835:Ecological
3820:Biological
3551:January 2,
3413:2013-05-03
2587:. Newnes.
2345:2014-06-08
2052:References
1885:The term "
1872:James Watt
1864:millstones
1854:had built
1770:World Bank
1574:baroreflex
1554:See also:
1492:See also:
560:electrical
537:regulation
517:subtracted
463:Allostasis
453:See also:
424:processes.
357:functions.
316:distortion
314:, reduces
308:amplifiers
3948:Systemics
3377:CiteSeerX
3354:0921-8181
3295:0036-8075
3243:0894-8755
3194:1944-8007
3137:1476-4687
2420:CiteSeerX
2389:0921-8181
1966:balancing
1868:windmills
1833:Ktesibios
1752:financier
1748:heterodox
1710:Economics
1698:Emergence
1647:Chemistry
1627:secretes
1606:endocrine
1445:β
1292:loop gain
1263:β
1249:β
1243:−
1234:β
1201:β
1198:−
1178:β
1175:−
1107:β
1083:β
1040:bandwidth
991:β
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890:oscillate
703:τ
691:τ
670:∫
568:regulator
525:regulator
414:organisms
351:logarithm
188:setpoints
165:mechanics
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3971:Analysis
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3074:Archived
3070:nasa.gov
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1598:diabetes
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391:waveform
335:addition
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215:negative
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