The channel frequencies chosen represent a compromise between allowing enough bandwidth for video ( and hence satisfactory picture resolution ), and allowing enough channels to be packed into the available frequency band.

In 1967, a specific frequency from the emission spectrum of caesium-133 was chosen to be used in the definition of the second by the International System of Units.

In one common arrangement the resistor shown in the circuit above is replaced with a parallel-tuned circuit consisting of an inductor and capacitor in parallel, whose components are chosen to resonate the frequency of the input signal.

The frequency initially chosen for Galileo would have made it impossible for the US to block the Galileo signals without also interfering with their own GPS signals.

A grade of core material is chosen for best results for the frequency band.

They found that the second of ephemeris time ( ET ) had the duration of 9, 192, 631, 770 ± 20 cycles of the chosen caesium frequency.

This clock frequency, 3. 6864 MHz, was chosen ( in part ) to support the common asynchronous baud rates up to 38. 4 kbit / s using the SCC's internal baud-rate generator.

A more widely chosen distribution is the log-normal distribution where the number frequency is given as:

Whereas mechanical movements can typically be off by several seconds a day, an inexpensive quartz movement in a child's wristwatch may still be accurate to within half a second per day — ten times better than a mechanical movement .< ref > Quartz mechanisms usually have a resonant frequency of 32768 Hz, chosen for ease of use ( being 2 < sup > 15 </ sup >).

In other words, if two points in the waveform are chosen, and, and the time interval between them is kept constant, the frequency ratio will also be constant.

A filter chosen in anticipation of a certain sample frequency is called an anti-aliasing filter.

To minimise subcarrier visibility on a monochrome receiver it was necessary to make the color subcarrier an odd multiple of half the line scan frequency, the multiple originally chosen was 495.

This was the subcarrier frequency originally chosen, but tests showed that on a some monochrome receivers an interference pattern caused by the beat between the color subcarrier and the 4. 5 MHz sound intercarrier could be seen.

If the chosen anti-aliasing filter ( a low-pass filter in this case ) has a transition band of 2000 Hz, then the cut-off frequency should be ≤ 20050 Hz to yield a signal with negligible power at frequencies ≥ 22050 Hz and complete pass of frequencies ≤ 20 kHz ( within the human hearing range ).

In some cases it may even be relevant to consider a frequency function and impulse response of the filter which are chosen independently from each other.

The ideal impulse response can be chosen independently of the ideal frequency function and is in practice used to limit the effective width and to remove ringing effects of the resulting filter in the signal domain.

By chance, the Germans had chosen the operating frequency of the Wotan system very badly ; it operated on 45 MHz, which just happened to be the frequency of the powerful-but-dormant BBC television transmitter at Alexandra Palace.

This is accomplished by either or both of two techniques: the diaphragm's conductive coating is chosen and applied in a manner to give it a very high surface resistivity, and / or a large value resistor is placed in series between the EHT ( Extra High Tension or Voltage ) power supply and the diaphragm ( resistor not shown in the diagram here ). However the latter technique will still allow distortion as the charge will migrate across the diaphragm to the point closest to the " grid " or electrode thereby increasing the force moving the diaphragm, this will occur at audio frequency so the diaphragm requires a high resistance ( megohms ) to slow the movement of charge for a practical speaker.

The timestep must be chosen small enough to avoid discretization errors ( i. e. smaller than the fastest vibrational frequency in the system ).

One application is spectral inversion, typically of speech ; a carrier frequency is chosen to be above the highest speech frequencies ( which are low-pass filtered at, say, 3 kHz, for a carrier of perhaps 3. 3 kHz ), and the sum frequencies from the modulator are removed by more low-pass filtering.

The length from base to tip of the pyramid structure is chosen based on the lowest expected frequency and the amount of absorption required.

Another theory asserts the name was chosen based on the frequency of English alphabet letters due in part to the then current popularity of Douglas Hofstadter's 1980 book Gödel, Escher, Bach which used ETAOIN, etc., to capitalize on popularity and current hip-ness.

This frequency, like the RDS subcarrier frequency is chosen because it is the third harmonic of the 19 kHz pilot tone used in the FM-stereo transmission standard.

By this standard, it is determined that where two stations operating on the same frequency are involved, objectionable interference from station A exists at any point within the service area of station B where station A's signal is of an intensity one-twentieth or more of the strength of station B's signal at that point.

The effect of the recording is very open and natural, with the frequency emphasis exactly what you would expect from a live performance.

The frequency used for these experiments is 15 mc. and the transducer is a specially cut crystal with an epoxy lens capable of providing beam diameters smaller than one millimeter.

On the other hand, the temporary reduction in hypothalamic excitability through the injection of a barbiturate into the posterior hypothalamus causes a lessening in frequency and amplitude of cortical strychnine spikes until the hypothalamic excitability is restored.

In addition, the cutoff frequency for input accelerations is approximately proportional to the servo loop gain ; ;

The effect is that the platform returns from an off-level position at a rapid rate until it is nearly level, at which point the platform is controlled by a proportional servo with low enough frequency response so that the noise has little effect on the leveling process.

`` However, evidence that the Axis powers are making significant preparations indicative of such an intention is being reported with increasing frequency from a variety of sources.

We know that the number of radio and television impulses, sound waves, ultra-violet rays, etc., that may occupy the very same space, each solitary upon its own frequency, is infinite.

It is she who decides the time, the place, the surroundings, and the frequency of the sexual act.

The participating institutions each broadcast, in real time, a frequency signal with time codes, which is their estimate of TAI.

People tend to be less cooperative if they perceive that the frequency of helpers in the population is lower.

the relative frequency at bin and is the total area of the histogram.

Contrast this with frequency modulation, in which the frequency is varied, and phase modulation, in which the phase is varied.

The Spectrogram produced by such an instrument is a graphical display of the time varying pressure level and frequency profiles which give a specific acoustic signal its defining character.

The lowest possible energy an electron can take is therefore analogous to the fundamental frequency of a wave on a string.

it was noted by Bohr that the existence of any sort of wave packet implies uncertainty in the wave frequency and wavelength, since a spread of frequencies is needed to create the packet itself.

An equivalent definition is the radius of an unperturbed circular Newtonian orbit about the Sun of a particle having infinitesimal mass, moving with an angular frequency of radians per day ; or that length such that, when used to describe the positions of the objects in the Solar System, the heliocentric gravitational constant ( the product GM < sub >☉</ sub >) is equal to ()< sup > 2 </ sup > AU < sup > 3 </ sup >/ d < sup > 2 </ sup >.

The electromagnetic spectrum, in order of increasing frequency and decreasing wavelength, consists of radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays.

As frequency increases into the visible range, photons of EMR have enough energy to change the bond structure of some individual molecules.

As frequency increases beyond visible into the ultraviolet, photons now carry enough energy ( about three electron volts or more ) to excite certain doubly bonded molecules into permanent chemical rearrangement.

Most electromagnetic waves of higher frequency than visible light ( UV and X-rays ) are blocked by absorption from electronic excitation in ozone and dioxygen ( for UV ), and by ionization of air for energies in the extreme UV and above.

The frequency of these oscillations lies in the ultraviolet range for most metals, but it falls into the visible range for gold due to subtle relativistic effects that affect the orbitals around gold atoms.

Far more patients may experience a very mild form of IC / PBS, in which they have no visible wounds in their bladder, yet struggle with symptoms of pain, frequency, and / or urgency.

Infrared spectroscopy ( IR spectroscopy ) is the spectroscopy that deals with the infrared region of the electromagnetic spectrum, that is light with a longer wavelength and lower frequency than visible light.

The word laser started as an acronym for " light amplification by stimulated emission of radiation "; in modern usage " light " broadly denotes electromagnetic radiation of any frequency, not only visible light, hence infrared laser, ultraviolet laser, X-ray laser, and so on.

Primary properties of visible light are intensity, propagation direction, frequency or wavelength spectrum, and polarisation, while its speed in a vacuum, 299, 792, 458 meters per second ( about 300, 000 kilometers per second ), is one of the fundamental constants of nature.

For silver the limiting frequency is in the far UV, but for copper and gold it is closer to the visible.

We may calculate the ratio of the populations of the two states at room temperature ( T ≈ 300 K ) for an energy difference ΔE that corresponds to light of a frequency corresponding to visible light ( ν ≈ 5 × 10 < sup > 14 </ sup > Hz ).

Electromagnetic radiation is classified into types according to the frequency of the wave, these types include ( in order of increasing frequency ): radio waves, microwaves, terahertz radiation, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays.

More generally, where an observer detects electromagnetic radiation outside the visible spectrum, " redder " amounts to a technical shorthand for " increase in electromagnetic wavelength " — which also implies lower frequency and photon energy in accord with, respectively, the wave and quantum theories of light.

Sunlight, in the broad sense, is the total frequency spectrum of electromagnetic radiation given off by the Sun, particularly infrared, visible, and ultraviolet light.

It quickly became apparent that visible light, ultraviolet light, and infrared light ( phenomena thought previously to be unrelated ) were all electromagnetic waves of differing frequency.

In terms of the visible spectrum, " brown " refers to high wavelength ( low frequency ) hues, yellow, orange, or red, in combination with low luminance or saturation.

Often, the frequency spectrum clearly shows harmonics, visible as distinct spikes or lines, that provide insight into the mechanisms that generate the entire signal.

Also visible in this Spectrogram is a frequency fallback to 6 kHz after peaking, likely an artifact of the specific method employed to generate the waveform.

* The waves of visible light oscillate with a period ( reciprocal frequency ) of about 2 femtoseconds = ( 600x10 ^- 9 )/( 3x10 ^ 8 ) = 2. 0x10 ^- 15.

This aliasing is visible in images such as posters with lenticular printing: if they have low angular resolution, then as one moves past them, say from left-to-right, the 2D image does not initially change ( so it appears to move left ), then as one moves to the next angular image, the image suddenly changes ( so it jumps right ) – and the frequency and amplitude of this side-to-side movement corresponds to the angular resolution of the image ( and, for frequency, the speed of the viewer's lateral movement ), which is the angular aliasing of the 4D light field.

The decay of this excited state results in a relaxation of the energy levels of the electron, accompanied by emission of radiation whose frequency is in the visible region.

The light spectrum is usually measured at points ( often 31 ) along the visible spectrum, in wavelength space instead of frequency space, which makes it not strictly a spectral density.