Automotive

Greater safety through better communication at sea

Communication in the maritime environment is important for safety but does not always run smoothly. This can have catastrophic consequences. After all, 90% of all accidents at sea are caused by human error, and half of these ...

Energy & Green Tech

'Close the windows': Lebanon power plant sparks cancer fears

After losing four relatives to respiratory illness, Zeina Matar fled her hometown north of Lebanon's capital where she says a decaying power plant generates little electricity but very deadly pollution.

Engineering

Does traffic noise from flying cars cause stress?

Researchers from Nagoya University and Keio University in Japan have estimated a person's stress levels caused by the sound of a flying car passing overhead. The research was published in the Technical Journal of Advanced ...

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 ...

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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.

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