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.

Helix (multimedia project)

Helix DNA is a project to produce computer software that can play audio and video media in various formats, aid in producing such media, and serve them over a network. It is intended as a largely free and open source digital media framework that runs on numerous operating systems and processors (including mobile phones) and was started by RealNetworks which contributed much of the code. The Helix Community is an open collaborative effort to develop and extend the Helix DNA platform.

Helix DNA Client is a software package for multi-platform multi-format media playback. Helix Player is a media player that runs on Linux, Solaris, Symbian and FreeBSD and uses the Helix DNA Client. The Helix DNA Producer application aids in the production of media files, and Helix DNA Server can stream media files over a network.

Licenses

The code is released in binary and source code form under various licenses, notably the proprietary RealNetworks Community Source License and the free and open source software RealNetworks Public Source License. Additionally, the Helix DNA Client and the Helix Player are licensed under the popular GNU General Public License (GPL) free and open source license.

Christine (2016 film)

Christine is a 2016 American biographical film directed by Antonio Campos and written by Craig Shilowich. It stars actress Rebecca Hall as 1970s news reporter Christine Chubbuck who committed suicide on live television.

The film premiered at the 2016 Sundance Film Festival.

Plot

The film takes place in the last days of Christine Chubbuck's life as she struggles against depression and eventually commits suicide on-air.

Cast

References

External links

Christie (automobile company)

The Christine Direct Action Motor Company was a car company formed in 1904 and lasted until 1910.

History

The Christine Company was originally called Christine Iron Works, but the name was changed in 1906. Walter Christie was actually America's first exponent of front-wheel drive. In 1904, he took a four-cylinder, 30 hp racer to Daytona Beach with an early front-wheel drive system. In all, six racers were built, two with 60 hp engines.

Production models

The Christine Company produced a gran touring car in 1907 with a 50 hp engine costing $6,500 and 2,300 lbs. Also, the company produced a taxi cab.

Demise

Walter Christie spent most of his time racing and not promoting his cars. Because of this, the company folded in 1910.

Notes

Christine (1958 film)

Christine is a 1958 film, based on the novel Liebelei by Arthur Schnitzler. The film was directed by Pierre Gaspard-Huit and the title character was played by Romy Schneider. The cast included Alain Delon as a young lieutenant.

Schnitzler's play had been filmed in 1933 by Max Ophüls as Liebelei, starring Romy Schneider's mother, Magda Schneider.

Synopsis

In 1906 Vienna, a young lieutenant (Alain Delon) has an affair with a married baroness but decides to put an end to it when he meets Christine (Romy Schneider), a musician's daughter. It ends tragically when the Colonel learns his wife had this affair.

Cast

References

External links