Helix (ear)

The helix is the prominent rim of the auricle. Where the helix turns downwards posteriorly, a small tubercle is sometimes seen, namely the auricular tubercle of Darwin.

Additional images

The muscles of the auricula.

The muscles of the auricula.

Left: Darwin's tubercle. Right: the homologous point in a macaque.

Left: Darwin's tubercle. Right: the homologous point in a macaque.

External ear. Right auricle.Lateral view.

External ear. Right auricle.Lateral view.

External ear. Right auricle.Lateral view.

External ear. Right auricle.Lateral view.

External ear. Right auricle.Lateral view.

External ear. Right auricle.Lateral view.

See also

References

This article incorporates text in the public domain from the 20th edition of Gray's Anatomy (1918)

Ear

The ear is the organ of the sense of hearing, and in mammals is also an organ of balance. In mammals, the ear is usually described as having three parts—the outer ear, middle ear and the inner ear. The outer ear consists of the auricle or pinna, and the ear canal. The middle ear includes the tympanic cavity and the three ossicles. The inner ear consists of the bony labyrinth which contains the semicircular canals, and the utricle and saccule of the vestibular system, to do with balance, and the cochlea a part of the auditory system.

The ear develops from the first pharyngeal pouch and six small swellings that develop in the early embryo called otic placodes, which are derived from ectoderm.

A number of conditions may relate to the ear, including hearing loss, tinnitus and balance disorders including vertigo, however these may also relate to diseases affecting the pathways in the brain relating to hearing and balance.

Although the entire organ is considered as the ear, it is often just referred to as the visible outer part. In most mammals, the visible ear is a flap of tissue that is also called the pinna (or auricle in humans) and is the first stage in hearing. The ears of vertebrates are placed somewhat symmetrically on either side of the head, an arrangement that aids sound localization.

EAR (file format)

EAR (Enterprise ARchive) is a file format used by Java EE for packaging one or more modules into a single archive so that the deployment of the various modules onto an application server happens simultaneously and coherently. It also contains XML files called deployment descriptors which describe how to deploy the modules.

Ant, Maven, or Gradle can be used to build EAR files.

File structure

An EAR file is a standard JAR file (and therefore a Zip file) with a .ear extension, with one or more entries representing the modules of the application, and a metadata directory called META-INF which contains one or more deployment descriptors.

Module

Developers can embed various artifacts within an EAR file for deployment by application servers:

Ear (disambiguation)

The ear is the sense organ that detects sound.

Ear may also refer to:

EAR may refer to:

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.