*-algebra

In mathematics, and more specifically in abstract algebra, a *-algebra (or involutive algebra) is a mathematical structure consisting of two involutive rings R and A, where R is commutative and A has the structure of an associative algebra over R. Involutive algebras generalize the idea of a number system equipped with conjugation, for example the complex numbers and complex conjugation, matrices over the complex numbers and conjugate transpose, and linear operators over a Hilbert space and Hermitian adjoints.

Terminology

*-ring

In mathematics, a *-ring is a ring with a map * : A → A that is an antiautomorphism and an involution.

More precisely, * is required to satisfy the following properties:

for all x, y in A.

This is also called an involutive ring, involutory ring, and ring with involution. Note that the third axiom is actually redundant, because the second and fourth axioms imply 1* is also a multiplicative identity, and identities are unique.

Ring (Suzuki novel)

Ring (リング, Ringu) is a Japanese mystery horror novel by Koji Suzuki, first published in 1991, and set in modern-day Japan. It was the basis for a 1995 television film (Ring: Kanzenban),a television series (Ring: The Final Chapter), a film of the same name (1998's Ring), and two remakes of the 1998 film: a South Korean version (The Ring Virus) and an American version (The Ring).

Plot synopsis

After four teenagers mysteriously die simultaneously in Tokyo, Kazuyuki Asakawa, a reporter and uncle to one of the deceased, decides to launch his own personal investigation. His search leads him to "Hakone Pacific Land", a holiday resort where the youths were last seen together exactly one week before their deaths. Once there he happens upon a mysterious unmarked videotape. Watching the tape, he witnesses a strange sequence of both abstract and realistic footage, including an image of an injured man, that ends with a warning revealing the viewer has a week to live. Giving a single means of avoiding death, the tape's explanation ends suddenly having been overwritten by an advertisement. The tape has a horrible mental effect on Asakawa, and he doesn't doubt for a second that its warning is true.

Ring (software)

Ring (formerly SFLphone) is an open-source SIP/IAX2 compatible softphone for Linux, Windows and OS X. Ring is free software released under the GNU General Public License. Packages are available for all major distributions including Debian, openSUSE, Fedora, Mandriva and the latest Ubuntu releases.

Ring is one of the few softphones under Linux to support PulseAudio out of the box. The Ubuntu documentation recommends it for enterprise use because of features like conferencing and attended call transfer. In 2009, CIO magazine listed Ring (as SFLphone) among the top 5 open source VoIP softphones to watch.

It is maintained by Savoir-faire Linux.

French documentation is available on Ubuntu-fr website.

Ring design

Ring is based on a MVC model: Daemon and client are two separate processes that communicate through D-Bus. The Model is the daemon. Daemon handles all the processing including communication layer (SIP/IAX), audio capture and playback, etc. ... View is the GTK+ or KDE graphical user interface. Controller is D-Bus that enables communication between client and server.