Search results
Results from the WOW.Com Content Network
Audio feedback (also known as acoustic feedback, simply as feedback, or the Larsen effect) is a special kind of positive feedback which occurs when a sound loop exists between an audio input (for example, a microphone or guitar pickup) and an audio output (for example, a loudly-amplified loudspeaker).
Thus, a positive feedback loop is formed, which continues until the negative feedbacks bring the system to equilibrium. [7]: 969 Increases in atmospheric water vapor have been detected from satellites, and calculations based on these observations place this feedback strength at 1.85 ± 0.32 m 2 /K.
A feedback loop is created when all or some portion of the output is fed back to the input. A device is said to be operating open loop if no output feedback is being employed and closed loop if feedback is being used. [45] When two or more amplifiers are cross-coupled using positive feedback, complex behaviors can be created.
Positive climate change feedbacks amplify changes in the climate system, and can lead to destabilizing effects for the climate. [2] An increase in temperature from greenhouse gases leading to increased water vapor (which is itself a greenhouse gas) causing further warming is a positive feedback, but not a runaway effect, on Earth. [13]
An example of positive feedback is when a microphone picks up the sound that it is producing through a speaker, which is then played through the speaker, and so on. In addition to feedback, cybernetics is concerned with other forms of circular processes including: feedforward, recursion, and reflexivity.
A positive feedback loop speeds up a process. Meadows indicates that in most cases, it is preferable to slow down a positive loop, rather than speeding up a negative one. The eutrophication of a lake is a typical feedback loop that goes wild. In a eutrophic lake (which means well-nourished), much life, including fish, can be supported.
A fire–vegetation feedback describes the relationship between fire and the dominant vegetation type. An example of a highly flammable vegetation type is a grassland. Frequent fire will maintain grassland as the dominant vegetation in a positive feedback loop.
Bistability can be generated by a positive feedback loop with an ultrasensitive regulatory step. Positive feedback loops, such as the simple X activates Y and Y activates X motif, essentially link output signals to their input signals and have been noted to be an important regulatory motif in cellular signal transduction because positive ...