Dual or Duals may refer to:

Paired/two things

Dual (mathematics) In mathematics, a duality translates concepts, theorems or mathematical structures into other concepts, theorems or structures, in a one-to-one fashion, often (but not always) by means of an involution operation: if the dual of is , then the d ...

, a notion of paired concepts that mirror one another **

Dual (category theory) In category theory, a branch of mathematics, duality is a correspondence between the properties of a category ''C'' and the dual properties of the opposite category ''C''op. Given a statement regarding the category ''C'', by interchanging the sou ...

, a formalization of mathematical duality *** see more cases in :Duality theories *

Dual (grammatical number) Dual ( abbreviated ) is a grammatical number that some languages use in addition to singular and plural. When a noun or pronoun appears in dual form, it is interpreted as referring to precisely two of the entities (objects or persons) identified ...

, a grammatical category used in some languages *

Dual county Dual county ( ga, Contae déach) is a term used in Gaelic games to describe a county that competes at a similar level in both hurling and Gaelic football. For example, Dublin play in Division 1 in both the NHL and NFL, while Laois compete in ...

, a Gaelic games county which in both Gaelic football and hurling *

Dual diagnosis Dual diagnosis (also called co-occurring disorders (COD) or dual pathology) is the condition of having a mental illness and a comorbid substance use disorder. There is considerable debate surrounding the appropriateness of using a single categ ...

, a psychiatric diagnosis of co-occurrence of substance abuse and a mental problem * Dual fertilization, simultaneous application of a P-type and N-type

fertilizer A fertilizer (American English) or fertiliser (British English; see spelling differences) is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from ...

Dual impedance Dual impedance and dual network are terms used in electronic network analysis. The dual of an impedance Z is its reciprocal, or algebraic inverse Z'=\frac. For this reason the dual impedance is also called the inverse impedance. Another way of ...

, electrical circuits that are the dual of each other *

Dual SIM Some mobile phones support use of two SIM cards, described as dual SIM operation. When a second SIM card is installed, the phone either allows users to switch between two separate mobile network services manually, has hardware support for keeping ...

cellphone supporting use of two SIMs *

Aerochute International Dual The Aerochute International Dual, (formerly called the Two Seater) is an Australian powered parachute designed and produced by Aerochute International of Coburg North, Victoria. The aircraft is supplied as a kit for amateur construction.Be ...

a two-seat Australian powered parachute design

Acronyms and other uses

Dual (brand) Dual is a brand name of audio and video electronics. History In 1907, brothers Christian and Joseph Steidinger began manufacturing clockwork and gramophone parts in the Black Forest town of St. Georgen. In 1927, Gebrüder Steidinger (Steidinge ...

, a manufacturer of Hifi equipment *

DUAL (cognitive architecture) DUAL is a general cognitive architecture integrating the connectionist and symbolic approaches at the micro level. DUAL is based on decentralized representation and emergent computation. It was inspired by the Society of Mind idea proposed by Marv ...

, an artificial intelligence design model *

DUAL algorithm The diffusing update algorithm (DUAL) is the algorithm used by Cisco's EIGRP routing protocol to ensure that a given route is recalculated globally whenever it might cause a routing loop. It was developed by J.J. Garcia-Luna-Aceves at SRI Internatio ...

, or diffusing update algorithm, used to update Internet protocol routing tables * Dual language, alternative spelling of the Australian Aboriginal

Dhuwal language Dhuwal (also Dual, Duala) is one of the Yolŋu languages spoken by Aboriginal Australians in the Northern Territory, Australia. Although all Yolŋu languages are mutually intelligible to some extent, Dhuwal represents a distinct dialect continu ...

DUAL table The DUAL table is a special one-row, one-column table present by default in Oracle and other database installations. In Oracle, the table has a single VARCHAR2(1) column called DUMMY that has a value of 'X'. It is suitable for use in selecting a pse ...

, a special one-row and one-column database table *

Dual-Ghia Dual-Ghia is a rare, short-lived, automobile make, produced in the United States between 1956 and 1958. The idea for a sporty limited production car came from Eugene Casaroll, who controlled specialized vehicle builder Dual-Motors Corporation ba ...

, US-brand of luxury-car of the late 1950s

Media

* ''Dual'' (2008 film), a 2008 western drama film * ''Dual'' (2022 film), a 2022 science fiction thriller film * "Dual" (''Heroes''), an episode of ''Heroes'' *

Dual! Parallel Trouble Adventure is a Japanese anime series animated by AIC and created by Masaki Kajishima, best known for the '' Tenchi Muyo!'' franchise. It was originally broadcast on Wowow from April to July 1999 and was licensed in the US by Pioneer LDC, later know ...

, an anime series * ''Dual'' (album), an album of traditional Scottish and Irish music recorded by Éamonn Doorley, Muireann Nic Amhlaoibh, Julie Fowlis and Ross Martin, released 2008 * ''Dual'' (EP), a 2013 EP by Sampha * ''

Duals ''Duals'' is a compilation album by the Irish rock band U2. It was released in April 2011 to u2.com subscribers. Track listing :* "Where the Streets Have No Name" and "Amazing Grace" are studio mix of U2's performance at the Rose Bowl, P ...

'', an album by U2 * The Duals, American duo

Paired/two things

Acronyms and other uses

Media

See also