Computer Sciences

Sensor imperfections are perfect for forensic camera analysis

In a project aimed at developing intelligent tools to fight child exploitation, University of Groningen computer scientists have developed a system to analyze the noise produced by individual cameras. This information can ...

Energy & Green Tech

This electric flying boat might transform traveling

A Norwegian company is now developing a small electric seaplane that can transform local passenger traffic on a large scale. The design of the hull is currently being tested in SINTEF's towing tank in Trondheim, and the plan ...

Automotive

Tesla issues 2nd recall for obstructing pedestrian warning

Tesla is recalling nearly nearly 595,000 vehicles in the U.S., most for a second time, because a "Boombox" function can play sounds over an external speaker and obscure audible warnings for pedestrians.

Security

Security tool guarantees privacy in surveillance footage

Surveillance cameras have an identity problem, fueled by an inherent tension between utility and privacy. As these powerful little devices have cropped up seemingly everywhere, the use of machine learning tools has automated ...

page 1 from 9

Noise

In common use, the word noise means any unwanted sound. In both analog and digital electronics, noise is random unwanted perturbation to a wanted signal; it is called noise as a generalisation of the acoustic noise ("static") heard when listening to a weak radio transmission with significant electrical noise. Signal noise is heard as acoustic noise if the signal is converted into sound (e.g., played through a loudspeaker); it manifests as "snow" on a television or video image. High noise levels can block, distort, change or interfere with the meaning of a message in human, animal and electronic communication.

In signal processing or computing it can be considered random unwanted data without meaning; that is, data that is not being used to transmit a signal, but is simply produced as an unwanted by-product of other activities. "Signal-to-noise ratio" is sometimes used to refer to the ratio of useful to irrelevant information in an exchange.

In biology, noise can describe the variability of a measurement around the mean, for example transcriptional noise describes the variability in gene activity between cells in a population.

In many cases, the special case of thermal noise arises, which sets a fundamental lower limit to what can be measured or signaled and is related to basic physical processes described by thermodynamics, some of which are expressible by simple formulae.

In some fields, noise means unwanted information or data that is not relevant to the hypothesis or theory being investigated or tested.

This text uses material from Wikipedia, licensed under CC BY-SA