Vector space

A vector space (also called a linear space) is a collection of objects called vectors, which may be added together and multiplied ("scaled") by numbers, called scalars in this context. Scalars are often taken to be real numbers, but there are also vector spaces with scalar multiplication by complex numbers, rational numbers, or generally any field. The operations of vector addition and scalar multiplication must satisfy certain requirements, called axioms, listed below.

Euclidean vectors are an example of a vector space. They represent physical quantities such as forces: any two forces (of the same type) can be added to yield a third, and the multiplication of a force vector by a real multiplier is another force vector. In the same vein, but in a more geometric sense, vectors representing displacements in the plane or in three-dimensional space also form vector spaces. Vectors in vector spaces do not necessarily have to be arrow-like objects as they appear in the mentioned examples: vectors are regarded as abstract mathematical objects with particular properties, which in some cases can be visualized as arrows.

Vector Motors

Vector Motors Corporation is an American automobile manufacturer originally based in Wilmington, California. Its history can be traced to Vehicle Design Force, which was founded in 1978 by Gerald Wiegert. Vehicle production began in 1989 and ceased in the 1990s. The company was recently revived (as Vector Motors Corporation), and is currently developing a new supercar. Vector is credited by some as America's first attempt to compete with European performance car manufacturers like Ferrari, Lamborghini, and Lotus.

Nearly every car produced by the company is designated the letter "W" (for Wiegert) and a number. A letter "X" after the W (e.g. WX-8) signifies a prototype unit. The only exception to this rule is the Megatech-era M12, wherein the "M" stands for Megatech and the 12 signifies its V12 engine.

Origin

In 1971, Gerald Wiegert, fresh from college, founded a design house called Vehicle Design Force, and teamed up with Lee Brown, a well-known auto body expert in Hollywood, to create a new car called The Vector. The Vector was said to have various powerplants including a DOHC Porsche engine, and preproduction literature claimed that it would cost US$10,000 (when a new Rolls Royce Silver Shadow cost $11,500). None of these plans came to fruition, however, as Wiegert's planned production run never started. All that came of The Vector was an empty shell that was displayed at the Los Angeles Auto Show. Lee Brown left the design team shortly thereafter. The Vector was featured on the cover of Motor Trend magazine in April 1972. Wiegert renamed Vehicle Design Force to Vector Aeromotive after work began on a new project, the Vector W2.

Array data structure

In computer science, an array data structure, or simply an array, is a data structure consisting of a collection of elements (values or variables), each identified by at least one array index or key. An array is stored so that the position of each element can be computed from its index tuple by a mathematical formula. The simplest type of data structure is a linear array, also called one-dimensional array.

For example, an array of 10 32-bit integer variables, with indices 0 through 9, may be stored as 10 words at memory addresses 2000, 2004, 2008, ... 2036, so that the element with index i has the address 2000 + 4 × i.

Because the mathematical concept of a matrix can be represented as a two-dimensional grid, two-dimensional arrays are also sometimes called matrices. In some cases the term "vector" is used in computing to refer to an array, although tuples rather than vectors are more correctly the mathematical equivalent. Arrays are often used to implement tables, especially lookup tables; the word table is sometimes used as a synonym of array.

USA (disambiguation)

USA or U.S.A. usually refers to the United States of America, a country in North America.

USA or U.S.A. may also refer to:

Places

Business

Universities

Other uses

American Revolution

The American Revolution was a political upheaval that took place between 1765 and 1783 during which colonists in the Thirteen American Colonies rejected the British monarchy and aristocracy, overthrew the authority of Great Britain, and founded the United States of America.

Starting in 1765, members of American colonial society rejected the authority of the British Parliament to tax them without colonial representatives in the government. During the following decade, protests by colonists—known as Patriots—continued to escalate, as in the Boston Tea Party in 1773 during which patriots destroyed a consignment of taxed tea from the Parliament-controlled and favored East India Company. The British responded by imposing punitive laws—the Coercive Acts—on Massachusetts in 1774, following which Patriots in the other colonies rallied behind Massachusetts. In late 1774 the Patriots set up their own alternative government to better coordinate their resistance efforts against Great Britain, while other colonists, known as Loyalists, preferred to remain aligned to the British Crown.

USA-193

USA-193, also known as NRO launch 21 (NROL-21 or simply L-21), was a U.S. military reconnaissance satellite (radar imaging) launched on December 14, 2006. It was the first launch conducted by the United Launch Alliance. Owned by the National Reconnaissance Office (NRO), the craft's precise function and purpose were classified.

The satellite malfunctioned shortly after deployment, and was intentionally destroyed 14 months later on February 21, 2008, by a modified SM-3 missile fired from the warship USS Lake Erie, stationed west of Hawaii. The event highlighted growing distrust between the U.S. and China, and was viewed by some to be part of a wider "space race" involving the U.S., China, and Russia.

Design

USA-193 was part of the NRO's Future Imagery Architecture, which was begun in 1997 to produce a fleet of inexpensive reconnaissance satellites, but has become the agency's most spectacular failure. USA-193 was initially developed by Boeing, which won the contract in 1999, beating out Lockheed Martin with proposals for innovative electro-optics and radar. But after cost overruns, delays, and parts failures, NRO sent the contract to Lockheed, which built USA-193 around the Boeing radar design. Lockheed Martin and Boeing both supported the launch, the first in the joint effort known as the United Launch Alliance.