Quasigroup
In mathematics, especially in abstract algebra, a quasigroup is an algebraic structure resembling a group in the sense that "division" is always possible. Quasigroups differ from groups mainly in that they need not be associative.
A quasigroup with an identity element is called a loop.
Definitions
There are at least two equivalent formal definitions of quasigroup. One defines a quasigroup as a set with one binary operation, and the other, from universal algebra, defines a quasigroup as having three primitive operations. We begin with the first definition.
A quasigroup (Q, ∗) is a set, Q, with a binary operation, ∗, (that is, a magma), obeying the Latin square property. This states that, for each a and b in Q, there exist unique elements x and y in Q such that both
hold. (In other words: Each element of the set occurs exactly once in each row and exactly once in each column of the quasigroup's multiplication table, or Cayley table. This property ensures that the Cayley table of a finite quasigroup is a Latin square.)
Loopback
Loopback, or loop-back, refers to the routing of electronic signals, digital data streams, or flows of items back to their source without intentional processing or modification. This is primarily a means of testing the transmission or transportation infrastructure.
Many example applications exist. It may be a communication channel with only one communication endpoint. Any message transmitted by such a channel is immediately and only received by that same channel. In telecommunications, loopback devices perform transmission tests of access lines from the serving switching center, which usually does not require the assistance of personnel at the served terminal. Loop around is a method of testing between stations that are not necessarily adjacent, where in two lines are used, with the test being done at one station and the two lines are interconnected at the distant station. A patch cable may also function as loopback, when applied manually or automatically, remotely or locally, facilitating a loop-back test.
Requiem (Branford Marsalis album)
Requiem is a jazz trio album by the Branford Marsalis Quartet, featuring Branford Marsalis, Eric Revis, Jeff "Tain" Watts, and Kenny Kirkland. The recording, Kirkland's last before his death in November 1998, was dedicated to his memory. Recorded August 17–20 and December 9–10, 1998 in the Tarrytown Music Hall in Tarrytown, New York, the album reached Number 8 on the Billboard Top Jazz Albums chart.
After several years of recordings in trio and other formats, the Requiem recording reunited Marsalis and Watts with Kirkland, who had been his collaborator on many earlier outings. After the August recording sessions, the quartet took the material on the road, with the goal of returning to the studio after the material had been honed on stage. Following Kirkland's death the remaining players recorded as a trio, capturing the song "Elysium."
In his AllMusic review, Richard Ginell says the album "an uncompromising, well-played disc of acoustic jazz that leans a bit toward adventure at times… in what turned out to be the swan song for one of the neo-bop era's finest lineups." Josef Woodard, in Entertainment Weekly called the album an "inspiring set that showcases Marsalis' expressive fluidity and lends a rueful, finalizing punctuation mark to Kirkland's brilliant and too-brief career." Writing for AllAboutJazz.com, Ian Nicolson noted that the album captures "the sound of a hot, creative musician flourishing in a hot, creative environment, captured largely live on analogue 24-track." James Shell's review for JazzReview.com called the work "unquestionably Branford's best to date," noting "its reliance on the Keith Jarrett quartet of the mid-seventies as a model."
Requiem (Verdena album)
Requiem is the fourth album by the Italian alternative-rock band Verdena, released in 2007. It was published not only in Italy but also abroad: the same day in Switzerland, Germany and Austria on April 13 and April 16 in France.
Tracklist
References
Sanctuary (season 1)
The first season of the Canadian science fiction–fantasy television series Sanctuary premiered on the Sci Fi Channel in the United States on October 3, 2008, and concluded on ITV4 in the United Kingdom on January 5, 2009, after 13 episodes. It follows the actions of a secret organization known as the Sanctuary, who track down a series of creatures known as abnormals, and then bring them to the Sanctuary for refuge. The main story arc of the season involves the Sanctuary working against the Cabal, an organization who seek to control all abnormals for their own gain. Amanda Tapping, Robin Dunne, Emilie Ullerup, and Christopher Heyerdahl are billed in the opening credits as the main cast.
Initially an eight-part web series, Sanctuary was successful enough for Sci Fi to commission a television series. Series creator and head writer Damian Kindler hired Sam Egan, and the two wrote all the episodes and composed the season-long storyline. Many episodes had been written throughout the 2007 Christmas season before the season was green-lit. Principal photography started in May 2008. It was the first instance in North American television where RED cameras were used. Most of the season was filmed using green screen in a warehouse in Burnaby, British Columbia, though there are instances throughout that were filmed on location, including the Riverview Hospital in Coquitlam and the North Shore Mountains outside Vancouver. Anthem Visual Effects produced the season's visual effects. The virtual sets meant that they produced around 400 visual effects per episode. Other forms of special effects, including prosthetics, were used to present the abnormals. The first season was budgeted at an estimated $21 million.
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