QR may refer to:

Arts and entertainment

Nippon Cultural Broadcasting is a Japanese radio station in Tokyo which broadcasts to the Kanto area. It is one of the two flagship radio stations of National Radio Network (NRN) (the other station is ) and is a member of the Fujisankei Communications Group. History The ...

(from call sign JOQR), a Tokyo radio station * Queen's Radio, a student radio station at Queen's University Belfast *

Quiet Riot Quiet Riot is an American heavy metal band founded in Los Angeles in 1973 by guitarist Randy Rhoads and bassist Kelly Garni. The original lineup featured Rhoads and Garni with lead vocalist Kevin DuBrow and drummer Drew Forsyth, though th ...

, an American rock band

Businesses

Qatar Airways Qatar Airways Company Q.C.S.C. ( ar, القطرية, ''al-Qaṭariya''), operating as Qatar Airways, is the state-owned flag carrier airline of Qatar. Headquartered in the Qatar Airways Tower in Doha, the airline operates a hub-and-spoke netwo ...

(IATA code) *

Queensland Rail Queensland Rail (QR) is a railway operator in Queensland, Australia. Owned by the Queensland Government, it operates local and long-distance passenger services, as well as owning and maintaining approximately 6,600 kilometres of track and relate ...

, a company responsible for the railway system in Queensland, Australia * Quintana Roo (company), a triathlon-specific wetsuit and bicycle company

Places

Quintana Roo Quintana Roo ( , ), officially the Free and Sovereign State of Quintana Roo ( es, Estado Libre y Soberano de Quintana Roo), is one of the 31 states which, with Mexico City, constitute the 32 federal entities of Mexico. It is divided into 11 mu ...

, a state of Mexico *

Karakalpakstan Karakalpakstan, / officially the Republic of Karakalpakstan, / is an autonomous republic of Uzbekistan. It occupies the whole northwestern part of Uzbekistan. The capital is Nukus (' / ). The Republic of Karakalpakstan has an area of , and ...

(Qoraqalpog'iston Respublikasi), Uzbekistan (ISO 3166-2 subcode UZ-QR)

Science and technology

QR code A QR code (an initialism for quick response code) is a type of matrix barcode (or two-dimensional barcode) invented in 1994 by the Japanese company Denso Wave. A barcode is a machine-readable optical label that can contain information about th ...

(Quick Response code), a two-dimensional code * ATCvet code QR ''Respiratory system'', a section of the Anatomical Therapeutic Chemical Classification System for veterinary medicinal products * DICOM Q/R, DICOM Query / Retrieve *

Nissan QR engine The QR family of inline-four piston engines by Nissan were introduced in 2000 and range from in displacement. These motors are aluminum, dual overhead camshaft (DOHC), four-valve designs with variable valve timing and optional direct injection. ...

Mathematics

QR decomposition In linear algebra, a QR decomposition, also known as a QR factorization or QU factorization, is a decomposition of a matrix ''A'' into a product ''A'' = ''QR'' of an orthogonal matrix ''Q'' and an upper triangular matrix ''R''. QR decomp ...

, a decomposition of a matrix *

QR algorithm In numerical linear algebra, the QR algorithm or QR iteration is an eigenvalue algorithm: that is, a procedure to calculate the eigenvalues and eigenvectors of a matrix. The QR algorithm was developed in the late 1950s by John G. F. Francis and by ...

, an eigenvalue algorithm using QR decomposition *

Quadratic reciprocity In number theory, the law of quadratic reciprocity is a theorem about modular arithmetic that gives conditions for the solvability of quadratic equations modulo prime numbers. Due to its subtlety, it has many formulations, but the most standard st ...

, a theorem from modular arithmetic *

Quasireversibility In queueing theory, a discipline within the mathematical theory of probability, quasireversibility (sometimes QR) is a property of some queues. The concept was first identified by Richard R. Muntz and further developed by Frank Kelly Francis ...

, a property of some queues *

Reaction quotient In chemical thermodynamics, the reaction quotient (''Q''r or just ''Q'') is a dimensionless quantity that provides a measurement of the relative amounts of products and reactants present in a reaction mixture for a reaction with well-defined overall ...

(Q_r), a function of the activities or concentrations of the chemical species involved in a chemical reaction

Other uses

* ''

Quarterly Review The ''Quarterly Review'' was a literary and political periodical founded in March 1809 by London publishing house John Murray. It ceased publication in 1967. It was referred to as ''The London Quarterly Review'', as reprinted by Leonard Scott, f ...

'', a defunct literary and political periodical *

Qatari riyal The Qatari riyal (sign: QR in Latin, in Arabic; ISO code: QAR) is the currency of the State of Qatar. It is divided into 100 dirhams ( ar, درهم). History Until 1966, Qatar used the Indian rupee as its currency, in the form of Gulf rupees. ...

, the currency of Qatar {{disambiguation