# Deviation

(redirected from deviated)
Also found in: Dictionary, Thesaurus, Medical, Legal, Idioms, Wikipedia.

## deviation

[‚dēv·ē′ā·shən]
(engineering)
The difference between the actual value of a controlled variable and the desired value corresponding to the set point.
(evolution)
Evolutionary differentiation involving interpolation of new stages in the ancestral pattern of morphogenesis.
(optics)
The angle between the incident ray on an object or optical system and the emergent ray, following reflection, refraction, or diffraction. Also known as angle of deviation.
(petroleum engineering)
During a drilling operation, the inclination of the borehole from the vertical.
(statistics)
The difference between any given number in a set and the mean average of those numbers.

## Deviation

in artillery, an accidental phenomenon not allowed for in the laws of dispersion, by which shells (bullets) veer away from the mean trajectory expected under the given firing conditions. Causes of deviation may be the mechanical disruption of the movement of the shell in the bore (for example, separation of the shell from the rifling grooves) or in the air (for example, a defect in the stabilizer fins or other parts), as well as a chance sharp change in weather conditions during the flight of the shell.

## Deviation

in biology, a variety of phylembryogenesis in which a change in the development of an organ arises in the middle stages of its formation and results in a change in the structure of the organ in the adult organism, compared with the same organ in its ancestors. For example, in the middle stages of development the epidermal part of the scale buds of reptiles undergoes keratinization, not ossification (as in sharks). The term “deviation” was introduced by the German scientist F. Müller (1864).

## Deviation

the most common measure of dispersion, that is, deviation from the mean, in mathematical statistics and theory of probability. In the statistical sense, deviation

is the arithmetic mean of the squares of the deviations of the values Xi from their arithmetic mean

In the theory of probability the deviation (variance) of a random variable X is called the expected value E(X - mx)2 of the square of the deviation of X from its expected value mx =E(X). The deviation of a random variable X is denoted by D(X) or by σ2). The square root of the deviation (that is, if the deviation is σ2) is called standard deviation.

For a random variable X with continuous probability distribution, characterized by probability density p(x), deviation is calculated by the formula

where

The following theorem has great significance in the theory of probability: the deviation of the sum of independent terms is equal to the sum of their deviations. No less important is Chebyshev’s inequality, which allows us to evaluate the probability of large deviations of the random variable X from its expected value.

### REFERENCE

Gnedenko, B. V. Kurs teorii veroiatnostei, 5th ed. Moscow, 1969.

## deviation

i. The angular difference between a magnetic and a compass heading. It is a compass error caused by the compass magnet attempting to align with the aircraft's local magnetic field. The deviation error changes with the aircraft heading and the latitude. It is measured in degrees east (+) or west (−), depending on whether the north-seeking end of the compass needle lies to the east or west of magnetic north.
ii. The angle between the wind and the pressure gradient.
iii. In frequency modulation, the amount the carrier increases or decreases when modulated.
vi A departure from a current clearance, such as an off-course maneuver, to avoid bad weather or turbulence.
v A variation from set rules and regulations. Where specifically authorized in the regulation and requested by the pilot, ATC (air traffic control) may permit pilots to deviate from certain regulations.
vi. In flight, a sudden excursion from the normal flight path.
vii. The distance by which a weapon misses its target.
References in periodicals archive ?
The magnitude of nasal obstruction in a caudally deviated septum is perplexing predominantly due to the fact that the deviation is bounded laterally by nasal valve area.
However in adults a higher percentage of males are found to have deviated septum than females.
Symptoms tend to get worse with time, and persons with deviated septums are more susceptible to local nasal infections than those with normal or corrected septums.
A vertical incision was made caudal to the deviation or deviation part of septum but it is not extended from dorsal of nose to the floor of nose as in conventional sepyoplasty, but extended both superiorly and inferiorly to explore the most deviated part.
The propofol expert witness also admitted that Dr Murray deviated from commonly accepted medical standards.
Permanent blockade of the draining channels (Osteo Meatal Unit) by this Deviated Nasal Septum may cause chronic persisting disease.
London, Dec 29 (ANI): Helena Bonham Carter has revealed that her partner Tim Burton is refusing to undergo a surgery to fix a deviated septum to prevent him from snoring and keeping her up at night.
Brokerages covering the company rounded their estimates up or down a penny afterward but deviated no further from the norm.
Classifying 831 galaxies, the computer deviated from a panel of six expert observers only 9 percent of the time.
Next week, he will undergo nasal surgery to repair a deviated septum and a lingering sinus infection.
For instance, he says, Spiegel's small sample of controls may have deviated form the national survival rate purely by chance.

Site: Follow: Share:
Open / Close