ARC (file format)

ARC is a lossless data compression and archival format by System Enhancement Associates (SEA). It was very popular during the early days of networked dial-up BBS. The file format and the program were both called ARC. The ARC program made obsolete the previous use of a combination of the SQ program to compress files and the LU program to create .LBR archives, by combining both compression and archiving functions into a single program. Unlike ZIP, ARC is incapable of compressing entire directory trees. The format was subject to controversy in the 1980s—an important event in debates over what would later be known as open formats.

The .arc file extension is often used for several file archive-like file types. For example, the Internet Archive uses its own ARC format to store multiple web resources into a single file. The FreeArc archiver also uses .arc extension, but uses a completely different file format.

Nintendo uses an unrelated 'ARC' format for resources, such as MIDI, voice samples, or text, in GameCube and Wii games. Several unofficial extractors exist for this type of ARC file.

Arc (projective geometry)

A (simple) arc in finite projective geometry is a set of points which satisfies, in an intuitive way, a feature of curved figures in continuous geometries. Loosely speaking, they are sets of points that are far from "line-like" in a plane or far from "plane-like" in a three-dimensional space. In this finite setting it is typical to include the number of points in the set in the name, so these simple arcs are called k-arcs. An important generalization of the k-arc concept, also referred to as arcs in the literature, are the (k, d)-arcs.

k-arcs in a projective plane

In a finite projective plane π (not necessarily Desarguesian) a set A of k (k ≥ 3) points such that no three points of A are collinear (on a line) is called a k - arc. If the plane π has order q then k ≤ q + 2, however the maximum value of k can only be achieved if q is even. In a plane of order q, a (q + 1)-arc is called an oval and, if q is even, a (q + 2)-arc is called a hyperoval.

Every conic in the Desarguesian projective plane PG(2,q), i.e., the set of zeros of an irreducible homogeneous quadratic equation, is an oval. A celebrated result of Beniamino Segre states that when q is odd, every (q + 1)-arc in PG(2,q) is a conic. This is one of the pioneering results in finite geometry.

Directed graph

In mathematics, and more specifically in graph theory, a directed graph (or digraph) is a graph, or set of vertices connected by edges, where the edges have a direction associated with them. In formal terms, a directed graph is an ordered pair G = (V, A) (sometimes G = (V, E)) where

It differs from an ordinary or undirected graph, in that the latter is defined in terms of unordered pairs of vertices, which are usually called edges, arcs, or lines.

A directed graph is called a simple digraph if it has no multiple arrows (two or more edges that connect the same two vertices in the same direction) and no loops (edges that connect vertices to themselves). A directed graph is called a directed multigraph or multidigraph if it may have multiple arrows (and sometimes loops). In the latter case the arrow set forms a multiset, rather than a set, of ordered pairs of vertices.

Lessness (short story)

"Lessness" is a short story by Samuel Beckett originally written in French as "Sans" in 1969, and later translated into English by the author. It was partly inspired by John Cage and the experimental music of the 1960s. The story was included in a book of short stories under the title Friendship launched in 1990 to coincide with the fourth anniversary of the kidnapping in Beirut of the British television journalist John McCarthy.

References

Şans

Şans is second studio album by the Turkish R&B singer, Murat Boz. It was released on February 24, 2009. The album has so far produced eight singles.

Singles

Tracklist

Source:

References

AC power plugs and sockets: British and related types

Plugs and sockets for electrical appliances not hardwired to mains electricity originated in Britain in the 1880s and were initially two-pin designs. These were usually sold as a mating pair, but gradually de facto and then official standards arose to enable the interchange of compatible devices. British standards have proliferated throughout large parts of the former British Empire.

BS 546, Two-pole and earthing-pin plugs, socket-outlets and socket-outlet adaptors for AC (50-60 Hz) circuits up to 250 V is a British Standard for three pin AC power plugs and sockets. Originally published in April 1934, it was updated by a 1950 edition which is still current, with eight amendments up to 1999. BS 546 is also the precursor of current Indian and South African plug standards. The 5 A version has been designated as Type D and the 15 A as Type M. BS 546 plugs and sockets are still permitted in the UK, provided the socket has shutters.

BS 1363, 13 A plugs socket-outlets adaptors and connection units is a British Standard which specifies the most common type of single-phase AC power plugs and sockets that are used in the United Kingdom. Distinctive characteristics of the system are shutters on the neutral and line (see Concepts and Terminology below) socket holes, and a fuse in the plug. It has been adopted in many former British overseas territories. BS 1363 was introduced in 1947 as one of the new standards for electrical wiring in the United Kingdom used for post-war reconstruction. The plug and socket replaced the BS 546 plug and socket, which are still found in old installations or in special applications. BS 1363 plugs have been designated as Type G