adaptive mesh refinement (AMR)
nâzokeš-e niyâveši-ye bâncé
Fr.: raffinement de maillage adaptatif
A type of → algorithm that dynamically achieves high
→ resolution in localized regions of multidimensional
→ numerical simulations.
AMR provides a higher → accuracy solution at
lower costs, through an automatically → optimal
distribution of → grid points for the
computation region. It relies on locally refined mesh or mesh
patches to increase the resolution of an underlying
coarse mesh only where needed.
It can alleviate some of the complexities of the generation of high
quality grid and reduce the number of → iterations of
"trial-and-error" between the grid generation and solution
required for tailoring the grid to the specification of a
problem. Thus, it can offer orders of magnitude saving in
computational and storage costs over an equivalent uniformly refined
mesh. AMR was originally developed for → inviscid,
→ compressible flow (Berger et al., 1984,
Adaptive Mesh Refinement for Hyperbolic Partial Differential
Equations. J. Comp. Phy., 53, 484). It
has been extended to solve → Navier-Stokes equations,
time dependent problems and more. Several
AMR techniques have been developed and applied to compressible flow fields to capture
characteristics at the strong gradient or discontinuous regions requiring higher space resolution,
such as regions involving → shock waves,
vortices (→ vortex), and
(see, e.g., Qingluan Xue, "Development of Adaptive Mesh Refinement Scheme and
Conjugate Heat Transfer Model for Engine Simulations" (2009), Iowa State Univ., Graduate
Theses and Dissertations, Paper 10678).
Fr.: optique adaptative
A technique for improving the → image quality of a telescope against → atmospheric turbulence in which image distortions are compensated by high-speed changes in the shape of a small, thin mirror. → wavefront; → wavefront distortion; → wavefront correction; → Strehl ratio; → tip-tilt mirror, → Shack-Hartmann wavefront sensor, → active optics.
ADaptive Optics Near Infrared System (ADONIS)
Fr.: ADaptive Optics Near Infrared System (ADONIS)
An → adaptive optics instrument used on the → European Southern Observatory (ESO) 3.6-m telescope at La Silla. It was an upgraded version of COME-ON-PLUS, the → Very Large Telescope (VLT) adaptive optics prototype. It had 52 → actuators and performed corrections of the mirror 200 times per second. The reference → wavefront was sensed in the → visible. The observation was done in the → near-infrared (1-5 μm).
adaptive optics system
râžmân-e nurik-e niyâveši
Fr.: système d'optique adaptative
1) To unite or so as to bring about an increase.
M.E. adden, from L. addere "add to, join," from → ad- "to" + -dere combining form meaning "to put, place," from dare "to give, grant," from PIE base *do- "to give" (cf. Av. and O.Pers. dâ- "to give, grant, yield," Av. dadâiti "he gives," Skt. dadâti "he gives," Gk. didomi "I give," L. do "I give").
Bardâyidan, from bar- "on; up; upon; in, into; at; forth,"
→ on-, + O.Pers./Av. dā- "to give, grant, put,"
dadāiti "he gives;" Mid.Pers./Mod.Pers.
dâdan "to give, put"
(cf. Skt. dadáti "he gives;"
Gk. tithenai "to place, put, set," didomi "I give;"
L. dare "to give, offer;"
Rus. delat' "to do;" O.H.G. tuon, Ger. tun,
O.E. don "to do;" PIE base *dhe- "to put, to do")
+ -y-, epenthetic vowel, + infinitive suffix -idan.
Fr.: quantité ajoutée
A number or quantity to be added to another. In the expression 5 + 3, both 5 and 3 are addends.
From L. addendus "that which is to be added," → add.
Bardâyé, from present stem bardây-, → add, + noun forming suffix -é.
The operation of combining two or more quantities to obtain a third quantity called their → sum. The result of adding.
Verbal noun of → add.
Fr.: signe d'addition
The → plus sign +. It is believed to be a shortened form of the letters e and t in the L. word et, which, in early German manuscripts was the term for addition. The signs + and - were first used by Johann Wiedmann in 1489.
1) bardâyeši; 2) bardâyé
1) Involving → addition.
Fr.: synthèse additive
Color created by mixing light rays of different colors. Combining all the color rays of light results in white light. See also → subtractive color.
Fr.: identité additive
The number which can be added to any other number without changing the magnitude of that number: zero. → multiplicative identity.
additive law of probability
qânun-e bardâyeši-ye šavânâyi
Fr.: loi additive de probabilité
If E1, E2, ..., En are n → mutually exclusive events, then the probability of occurrence of at least one of them is the sum of their individual probabilities: P(E1 + E2 + ... + En) = P(E1) + P(E2) + ... + P(En).
Adhara (ε Canis Majoris)
A binary star, in the constellation → Canis Major, 470 → light-years distant from Earth. The main star possesses an apparent magnitude of +1.5 and belongs to the spectral classification B2 II. The +7.5 magnitude companion star is 7''.5 apart from the main star.
Adhara, from Ar. adhârâ "virgins," plural of adhrâ' "virgin".
Azârâ, from Ar. Adhara.
1) To stay attached; stick fast; cling.
From M.Fr. adhérer or directly from L. adhaerere "to stick to," from → ad- + haerere "to stick."
Âdusidan, from intensive/nuance prefix â- + dusidan (Dehxodâ) "to stick, to adhere," maybe related to Proto-Ir. *dauc- "to sew;" Pers. duxtan, duz- "to sew."
1) The act or state of adhering; adhesion.
1) A person who follows or upholds a leader, cause, etc.; supporter; follower.
From O.Fr. adherent or directly from L. adhaerentem pr.p. of adhaerere "to stick to," → adhere.
Âdusandé, from âdusidan, → adhere.
1) The act or state of adhering; state of being adhered or united.
1) Of or pertaining to the molecular force → adhesion.
Adjective from → adhere.
Fr.: force adhésive
The force of → attraction between molecules of different substances; for example, the force between the molecules of a solid and a liquid. When water is poured on clean glass, it tends to spread, forming a thin, uniform film over the surface. This is because the adhesive forces between water and glass are strong enough to pull the water molecules out of their spherical formation and hold them against the surface of the glass, thus avoiding the repulsion between like molecules.