Fr.: loi du chi-deux
A probability density function, denoted χ2, that gives the distribution of the sum of squares of k independent random variables, each being drawn from the normal distribution with zero mean and unit variance. The integer k is the number of degrees of freedom. The distribution has a positive skew; the skew is less with more degrees of freedom. As degrees of freedom increase, the chi-square distribution approaches a normal distribution. The most common application is chi-square tests for goodness of fit of an observed distribution to a theoretical one. If χ2 = 0 the agreement is perfect.
inverse square law
qânun-e tavân-e do-ye vârun, qânun-e câruš-e vârun
Fr.: loi en carré inverse
Fr.: moindres carrés
Any statistical procedure that involves minimizing the sum of squared differences.
saz-e kucaktarin cârušhâ
Fr.: ajustement moindres carrées
A fit through data points using least squares.
method of least squares
raveš-e kamtarin cârušhâ
Fr.: méthode des moindres carrés
A method of fitting a curve to data points so as to minimize the sum of the squares of the distances of the points from the curve.
Fr.: carré parfait
root mean square (rms)
riše-ye câruši-ye miyângin, ~ dovom-e ~
Fr.: valeur quadratique moyenne
The square root of the arithmetic mean of the squares of the numbers in a given set.
irang-e riše-ye câruši-ye miyângin, ~ ~ dovom-e ~
The square root of the second moment corresponding to the frequency function of a random variable.
arzeš-e riše-ye câruši-ye miyângin
Fr.: écart quadratique moyen, écart type
Statistics: The square root of the arithmetic mean of the squares of the deviation of observed values from their arithmetic mean.
1) A rectangle having all four sides of equal length.
Câruš, from Av. caθruša- "four sides (of a four-sided figure)", from caθru- "four," Mod.Pers. cahâr, câr "four" + uša- "angle," Mod.Pers. guš, gušé.
Fr.: degré carré
A solid angle whose cone is a tetrahedral pyramid with an angle between its edges equal to 1°. 1 square degree = 3.046 x 10-4 sr = 2.424 x 10-5 solid angle of a complete sphere.
Square Kilometer Array (SKA)
An international project to construct a highly sensitive radio interferometer array operating between 0.15 and 20 GHz with an effective collecting area of one square kilometer. The number of individual telescopes will be 2000 to 3000. SKA will have a sensitivity 100 times higher than that of today's best radio telescopes and an angular resolution < 0.1 arcsec at 1.4 GHz. The site will be selected in 2012 and early science with Phase 1 is scheduled for from 2016 on. See also the SKA homepage.
Fr.: matrice carée
Square of Pegasus
Fr.: Carrée de Pégase
A large → asterism of four stars, approximately square in shape, in the northern sky. Three of the stars, → → Markab, → Scheat, and → Algenib, belong to the constellation → Pegasus. The fourth, → Alpheratz, was lost to Pegasus when the constellation boundaries were formalised, and now lies just within the borders of → Andromeda.
Fr.: racine carée
Quantity which when multiplied by itself produces another quantity.
Fr.: onde carrée
An oscillation which alternatively assumes, for equal lengths of time, one or two fixed values.
squaring the square
Fr.: quadrature du carré
The mathematical problem of subdividing a square into a number of smaller squares, all of different sizes.