Sim

Sim or SIM may refer to:

Computing and technology

Organizations

Sim (Korean surname)

Sim or Shim is a Korean surname. There are six Shim clans in Korea based in the regions ofCheongsong, Pungsan, Samcheok, Buyu, Uiryeong, and Jeonju. The biggest Sim clan is Cheongsong; they comprise about 85% of the all those with the surname Shim. Fourteen percent of all Korean Shims are members of the Pungsan and Samcheok clans. As of 2000, there were 252,255 people with this surname in South Korea, less than 1% of the population.

List of famous people

Sim (album)

Sim is the third album by Brazilian singer-songwriter Vanessa da Mata, released on May 28, 2007 by Sony BMG. It was partially recorded at Kingston, Jamaica with musicians Sly & Robbie. It spawned the hit single "Boa Sorte/Good Luck", a duet with Ben Harper, which peaked at number one in both Brazil and Portugal, and was the most played song in Brazilian radio stations in the year of 2008. The second single, "Amado", also became a number-one hit in Brazil and the 15th most played song in the same year.

Track listing

Dual (brand)

Dual (pronounced /duːˈɑːl/ or /-ˈæl/) 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 (Steidinger Bros.) adopted the name Dual in reference to the dual-mode power supplies it pioneered. The power supplies allowed gramophones to be powered from mains electricity or with a wind-up mechanism. Soon thereafter, Dual began producing turntables of its own.

After World War II, Dual became the biggest manufacturer of turntables in Europe, with more than 3,000 employees working in several factories. Throughout the 1970s, 1980s, and 1990s, Dual introduced audio cassette players, VCRs, CD players, and other consumer electronics.

But when Japanese consumer electronics started entering European markets in the 1970s on a large scale, Dual as most other traditional German manufacturers underwent a big crisis: Japanese products usually offered more features at a cheaper price in a much more modern package. Dual went bankrupt in 1982, and was sold to French electronic manufacturer Thomson SA. In 1988, Thomson sold Dual to German manufacturer Schneider Rundfunkwerke AG.

Duality (electrical circuits)

In electrical engineering, electrical terms are associated into pairs called duals. A dual of a relationship is formed by interchanging voltage and current in an expression. The dual expression thus produced is of the same form, and the reason that the dual is always a valid statement can be traced to the duality of electricity and magnetism.

Here is a partial list of electrical dualities:

History

The use of duality in circuit theory is due to Alexander Russell who published his ideas in 1904.

Examples

Constitutive relations

Voltage division — current division

Impedance and admittance

Duality (mathematics)

In mathematics, a duality, generally speaking, 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 A is B, then the dual of B is A. Such involutions sometimes have fixed points, so that the dual of A is A itself. For example, Desargues' theorem is self-dual in this sense under the standard duality in projective geometry.

In mathematical contexts, duality has numerous meanings although it is "a very pervasive and important concept in (modern) mathematics" and "an important general theme that has manifestations in almost every area of mathematics".

Many mathematical dualities between objects of two types correspond to pairings, bilinear functions from an object of one type and another object of the second type to some family of scalars. For instance, linear algebra duality corresponds in this way to bilinear maps from pairs of vector spaces to scalars, the duality between distributions and the associated test functions corresponds to the pairing in which one integrates a distribution against a test function, and Poincaré duality corresponds similarly to intersection number, viewed as a pairing between submanifolds of a given manifold.