frequency


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Related to frequency: frequency modulation, Sound frequency

frequency

1. Physics the number of times that a periodic function or vibration repeats itself in a specified time, often 1 second. It is usually measured in hertz.
2. Ecology
a. the number of individuals of a species within a given area
b. the percentage of quadrats that contains individuals of a species
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

Frequency (wave motion)

The number of times which sound pressure, electrical intensity, or other quantities specifying a wave vary from their equilibrium value through a complete cycle in unit time. The most common unit of frequency is the hertz (Hz), which is equal to 1 cycle per second. In one cycle there is a positive variation from equilibrium, a return to equilibrium, then a negative variation, and return to equilibrium. This relationship is often described in terms of the sine wave, and the frequency referred to is that of an equivalent sine-wave variation in the parameter under discussion. See Frequency measurement, Sine wave, Wave motion

McGraw-Hill Concise Encyclopedia of Physics. © 2002 by The McGraw-Hill Companies, Inc.

frequency

Symbol: f , ν. The number of oscillations per unit time of a vibrating system. Frequency is measured in hertz. The frequency of a wave is the number of wave crests passing a point per unit time. For light and other electromagnetic radiation, it is related to wavelength λ by ν = c /λ, where c is the speed of light.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006

frequency

[′frē·kwən·sē]
(physics)
The number of cycles completed by a periodic quantity in a unit time.
(statistics)
The number of times an event or item falls into or is expected to fall into a certain class or category.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

frequency

The number of oscillations per second (a) of the current or voltage in an alternating-current electric circuit, or (b) of a sound wave, or (c) of a vibrating solid object; expressed in hertz (abbr. Hz) or in cycles per second (abbr. cps).
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.

frequency

i. The number of recurrences of a periodic phenomenon in a unit of time.
ii. The number of cycles completed in one second. One cycle per second is the basic unit of measurement of frequency and is called a hertz .
iii. The number of services operated by an airline per day or per week over a particular route.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Frequency

The frequency of an event A is the ratio m/n of the number m of occurrences of A in a given series of trials to the total number n of trials. If the trials are independent and there is a definite probability p of the occurrence of A in an individual trial, then, for arbitrarily small ∊ > 0, at sufficiently large m it is practically certain that the frequency m/n satisfies the inequality

(seeLARGE NUMBERS, LAW OF and PROBABILITY).

The term “frequency” is used in mathematical statistics to designate the number of elements of a set that have a specified attribute.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
The NSS_Slovenia focuses on the relative frequency of the international security and security (research units 1, relative frequency (1)) enabling also: a) the security relational links between security risks and threats (research units 2, relative frequency (2)), national and internal seucirty environment (research units 1, relative frequency 6) and b) the settings of the rule of law (research units 1, relative frequency (4)), development encounters (research units 1, relative frequency (4)), migration and human rights fixings (research units 2, relative frequency (1)), security environment and climate change (research units 3, relative frequency (2)).
Targeting security topics usage in national security strategies: Core strategic concepts and security policies in Central and Eastern Europe
In this section, we extract gear fault features in the torsional resonance frequency region, instead of around gear meshing frequency and its harmonics that are usually focused in conventional methods.
Planetary Gearbox Fault Diagnosis via Torsional Vibration Signal Analysis in Resonance Region
Thus, when the original marker allele was distributed in the donor and receptor with a certain frequency, the foreground selection using MBLUP selection had more advantages.
Effects of Different Markers Frequency for Marker Assisted Introgression Efficiency
All telecommunications companies except for Vodafone obtained frequencies on the best frequency band of 900 MHz and part on the other frequency band.
Redistribution of 4G frequencies deprives Vodafone from obtaining best frequency band
All users of frequency spectrum are therefore advised in their own interest to stop using frequency spectrum without a valid license from PTA.
PTA raids illegal frequency user
The spacing between frequency spectrum lines in the FFT, or the width of frequency buckets that signal energy is apportioned to, is called the frequency resolution.
Scope FFT and waveform math functions take on RF measurements
Because frequency management is a process, our journey will be made through a series of process improvements.
The road to real-time frequency spectrum sharing
The software now indicates the spacing between a microphone frequency and its neighbouring frequencies to the 'left' and the 'right', whether this is another carrier or an intermodulation product.
Sennheiser releases latest WSM
In other words, said Mehta, "spike frequency refers to how fast the spikes come.
How the Brain Makes Memories: Rhythmically
Is there a similar relationship between the unemployment rate and medical professional liability claim frequency? To examine this possibility, we first took a look at claim frequency as measured by the National Practitioner Data Bank and compared it to the unemployment rate from 1991 through 2009 (graph 1).
History lessons: can studying past unemployment rates predict future medical professional liability claims frequency?
The petition stated that while Liberty was no longer engaged in broadcasting business, "and despite the underutilization or, worse, non-utilization at all of the conditionally assigned said frequencies within the prescribed period, respondent Liberty continued to illegally hoard the said 700 MHz broadcast frequency."
SC acts on petition challenging frequency assignments by NTC
Dakila Carlo Cua said his House Bill 8134 or 'An Act Systematizing Spectrum User Fees Imposed Against Radio Frequency Bands' will penalize telco companies who 'hoard' frequencies.
Lawmaker wants to punish telcos that 'hoard' frequencies

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