(harmonic filtering)
71Human voice — Voice redirects here. For other uses, see Voice (disambiguation). The spectrogram of the human voice reveals its rich harmonic content. The human voice consists of sound made by a human being using the vocal folds for talking, singing, laughing …
72Signal-to-noise ratio — For signal to noise ratio in statistics, see Cohen s d. Signal to noise ratio (often abbreviated SNR or S/N) is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. It is defined… …
73Sieve of Eratosthenes — Sieve of Eratosthenes: algorithm steps for primes below 121 (including optimization of starting from prime s square). In mathematics, the sieve of Eratosthenes (Greek: κόσκινον Ἐρατοσθένους), one of a number of prime number sieves, is a simple,… …
74Diode bridge — Three bridge rectifiers. The size is generally related to the current handling capability …
75Positive feedback — Alarm or panic can spread by positive feedback among a herd of animals to cause a stampede. Positive feedback is energy taken from the output of a system and reapplied to the input, which is phase congruent with the input signal. A system… …
76Solar variation — Solar variations are changes in the amount of solar radiation emitted by the Sun. There are periodic components to these variations, the principal one being the 11 year solar cycle (or sunspot cycle), as well as aperiodic fluctuations. Solar… …
77Fourier optics — is the study of classical optics using techniques involving Fourier transforms and can be seen as an extension of the Huygens Fresnel principle. The underlying theorem that light waves can be described as made up of sinusoidal waves, in a manner… …
78Variable-frequency oscillator — A variable frequency oscillator (VFO) in electronics is a oscillator with an oscillation frequency that can be electronically changed (hence, variable).cite book |title=The ARRL Handbook for Radio Amateurs, Sixty Eighth Edition |editor=Larry D.… …
79Lists of mathematics topics — This article itemizes the various lists of mathematics topics. Some of these lists link to hundreds of articles; some link only to a few. The extremely long list of mathematics articles contains all mathematical articles in alphabetical order.… …
80Industrial and multiphase power plugs and sockets — Industrial and multiphase plugs and sockets provide a connection to the electrical mains rated at higher voltages and currents than household plugs and sockets. They are generally used when more than two current carrying conductors (polyphase… …
