When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Frequency - Wikipedia

    en.wikipedia.org/wiki/Frequency

    The period T is the time taken to complete one cycle of an oscillation or rotation. The frequency and the period are related by the equation [4] =. The term temporal frequency is used to emphasise that the frequency is characterised by the number of occurrences of a repeating event per unit time.

  3. Wavenumber - Wikipedia

    en.wikipedia.org/wiki/Wavenumber

    For example, a wavenumber in inverse centimeters can be converted to a frequency expressed in the unit gigahertz by multiplying by 29.979 2458 cm/ns (the speed of light, in centimeters per nanosecond); [5] conversely, an electromagnetic wave at 29.9792458 GHz has a wavelength of 1 cm in free space.

  4. Frequency domain - Wikipedia

    en.wikipedia.org/wiki/Frequency_domain

    One of the main reasons for using a frequency-domain representation of a problem is to simplify the mathematical analysis. For mathematical systems governed by linear differential equations, a very important class of systems with many real-world applications, converting the description of the system from the time domain to a frequency domain converts the differential equations to algebraic ...

  5. Sampling (signal processing) - Wikipedia

    en.wikipedia.org/wiki/Sampling_(signal_processing)

    The image sampling frequency is the repetition rate of the sensor integration period. Since the integration period may be significantly shorter than the time between repetitions, the sampling frequency can be different from the inverse of the sample time: 50 Hz – PAL video; 60 / 1.001 Hz ~= 59.94 Hz – NTSC video

  6. Duty cycle - Wikipedia

    en.wikipedia.org/wiki/Duty_cycle

    A duty cycle or power cycle is the fraction of one period in which a signal or system is active. [1] [2] [3] Duty cycle is commonly expressed as a percentage or a ratio. A period is the time it takes for a signal to complete an on-and-off cycle. As a formula, a duty cycle (%) may be expressed as: = % [2]

  7. Welch's method - Wikipedia

    en.wikipedia.org/wiki/Welch's_method

    The method is based on the concept of using periodogram spectrum estimates, which are the result of converting a signal from the time domain to the frequency domain. Welch's method is an improvement on the standard periodogram spectrum estimating method and on Bartlett's method , in that it reduces noise in the estimated power spectra in ...

  8. Return period - Wikipedia

    en.wikipedia.org/wiki/Return_period

    The theoretical return period between occurrences is the inverse of the average frequency of occurrence. For example, a 10-year flood has a 1/10 = 0.1 or 10% chance of being exceeded in any one year and a 50-year flood has a 0.02 or 2% chance of being exceeded in any one year.

  9. Unit of time - Wikipedia

    en.wikipedia.org/wiki/Unit_of_time

    10 nanoseconds, also a casual term for a short period of time. microsecond: 10 −6 s: One millionth of a second. Symbol is μs millisecond: 10 −3 s: One thousandth of a second. Shortest time unit used on stopwatches. jiffy (electronics) ~ 10 −3 s: Used to measure the time between alternating power cycles. Also a casual term for a short ...