Helix
A helix (pl: helixes or helices) is a type of smooth space curve, i.e. a curve in three-dimensional space. It has the property that the tangent line at any point makes a constant angle with a fixed line called the axis. Examples of helices are coil springs and the handrails of spiral staircases. A "filled-in" helix – for example, a spiral ramp – is called a helicoid. Helices are important in biology, as the DNA molecule is formed as two intertwined helices, and many proteins have helical substructures, known as alpha helices. The word helix comes from the Greek word ἕλιξ, "twisted, curved".
Types
Helices can be either right-handed or left-handed. With the line of sight along the helix's axis, if a clockwise screwing motion moves the helix away from the observer, then it is called a right-handed helix; if towards the observer, then it is a left-handed helix. Handedness (or chirality) is a property of the helix, not of the perspective: a right-handed helix cannot be turned to look like a left-handed one unless it is viewed in a mirror, and vice versa.
Phelix
Phelix is a high-speed stream cipher with a built-in single-pass message authentication code (MAC) functionality, submitted in 2004 to the eSTREAM contest by Doug Whiting, Bruce Schneier, Stefan Lucks, and Frédéric Muller. The cipher uses only the operations of addition modulo 232, exclusive or, and rotation by a fixed number of bits. Phelix uses a 256-bit key and a 128-bit nonce, claiming a design strength of 128 bits. Concerns have been raised over the ability to recover the secret key if the cipher is used incorrectly.
Performance
Phelix is optimised for 32-bit platforms. The authors state that it can achieve up to eight cycles per byte on modern x86-based processors.
FPGA Hardware performance figures published in the paper "Review of stream cipher candidates from a low resource hardware perspective" are as follows:
Helix
Phelix is a slightly modified form of an earlier cipher, Helix, published in 2003 by Niels Ferguson, Doug Whiting, Bruce Schneier, John Kelsey, Stefan Lucks, and Tadayoshi Kohno; Phelix adds 128 bits to the internal state.
Noun
A noun (from Latin nōmen, literally meaning "name") is a word that functions as the name of some specific thing or set of things, such as living creatures, objects, places, actions, qualities, states of existence, or ideas.Linguistically, a noun is a member of a large, open part of speech whose members can occur as the main word in the subject of a clause, the object of a verb, or the object of a preposition.
Lexical categories (parts of speech) are defined in terms of the ways in which their members combine with other kinds of expressions. The syntactic rules for nouns differ from language to language. In English, nouns are those words which can occur with articles and attributive adjectives and can function as the head of a noun phrase.
History
Word classes (parts of speech) were described by Sanskrit grammarians from at least the 5th century BC. In Yāska's Nirukta, the noun (nāma) is one of the four main categories of words defined.
The Ancient Greek equivalent was ónoma (ὄνομα), referred to by Plato in the Cratylus dialog, and later listed as one of the eight parts of speech in The Art of Grammar, attributed to Dionysius Thrax (2nd century BC). The term used in Latin grammar was nōmen. All of these terms for "noun" were also words meaning "name". The English word noun is derived from the Latin term, through the Anglo-Norman noun.
Happy (disambiguation)
To be happy is to experience happiness: a feeling of contentment or joy.
Happy may also refer to:
Film and television
Music
Bands
Albums
Songs
Happy (Michael Jackson song)
"Happy" is a song recorded by Michael Jackson for the Motown label in 1973. The song featured on Jackson's album Music & Me. Its full title is "Happy (Love Theme from Lady Sings the Blues)", although it was never featured in the film or the soundtrack for Lady Sings the Blues. The song was released as a single in Australia, backed by "In Our Small Way".
Jackson continued to perform the track in concert as late as 1977, citing it as one of his favorite songs.
The song was not released as a single in the UK until 1983 to promote Motown's 18 Greatest Hits compilation album, on which the song was included. Upon its release, "Happy" (credited to Michael Jackson plus The Jackson 5) peaked at #52 on the British pop chart. It was also issued as a single by Bobby Darin and included on his posthumous Motown LP Darin: 1936-1973. It was later recorded by the song's composer, Smokey Robinson, and appeared on his landmark solo album A Quiet Storm.
According to Robinson, the song was inspired by the film's melody, which was originally composed by Michel Legrand. He explained, "I was looking at the movie one day, and I was listening to that melody, and I thought it was just such a beautiful melody, until I wanted to write some words for that melody, which I did, and I went and I sang them for Berry Gordy, and he was really upset because I didn't write them before he finished the movie so they could've been in the movie."
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