When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Signal-to-noise ratio - Wikipedia

    en.wikipedia.org/wiki/Signal-to-noise_ratio

    Signal-to-noise ratio (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. SNR is defined as the ratio of signal power to noise power, often expressed in decibels. A ratio higher than 1:1 (greater than 0 dB) indicates more signal than noise.

  3. Power (statistics) - Wikipedia

    en.wikipedia.org/wiki/Power_(statistics)

    The main application of statistical power is "power analysis", a calculation of power usually done before an experiment is conducted using data from pilot studies or a literature review. Power analyses can be used to calculate the minimum sample size required so that one can be reasonably likely to detect an effect of a given size (in other ...

  4. Neper - Wikipedia

    en.wikipedia.org/wiki/Neper

    The neper is defined in terms of ratios of field quantities — also called root-power quantities — (for example, voltage or current amplitudes in electrical circuits, or pressure in acoustics), whereas the decibel was originally defined in terms of power ratios. A power ratio 10 log r dB is equivalent to a field-quantity ratio 20 log r dB ...

  5. Spectral density - Wikipedia

    en.wikipedia.org/wiki/Spectral_density

    Energy spectral density (ESD) would have units of V 2 s Hz −1, since energy has units of power multiplied by time (e.g., watt-hour). [ 3 ] In the general case, the units of PSD will be the ratio of units of variance per unit of frequency; so, for example, a series of displacement values (in meters) over time (in seconds) will have PSD in ...

  6. List of dimensionless quantities - Wikipedia

    en.wikipedia.org/wiki/List_of_dimensionless...

    fluid mechanics, power consumption by rotary agitators; resistance force versus inertia force) Prater number: β = reaction engineering (ratio of heat evolution to heat conduction within a catalyst pellet) [16] Relative density: RD

  7. dBm - Wikipedia

    en.wikipedia.org/wiki/DBm

    dBm or dB mW (decibel-milliwatts) is a unit of power level expressed using a logarithmic decibel (dB) scale respective to one milliwatt (mW). It is commonly used by radio, microwave and fiber-optical communication technicians & engineers to measure the power of system transmissions on a log scale , which can express both very large and very ...

  8. Level (logarithmic quantity) - Wikipedia

    en.wikipedia.org/wiki/Level_(logarithmic_quantity)

    In science and engineering, a power level and a field level (also called a root-power level) are logarithmic magnitudes of certain quantities referenced to a standard reference value of the same type. A power level is a logarithmic quantity used to measure power, power density or sometimes energy, with commonly used unit decibel (dB).

  9. Channel capacity - Wikipedia

    en.wikipedia.org/wiki/Channel_capacity

    C is measured in bits per second if the logarithm is taken in base 2, or nats per second if the natural logarithm is used, assuming B is in hertz; the signal and noise powers S and N are expressed in a linear power unit (like watts or volts 2). Since S/N figures are often cited in dB, a conversion may be needed.