vocoder
Hardware or software which implements a compression algorithm particular to voice.
For example Qualcomm uses a vocoding algorithm to compresses voice data in digital communication systems such as wireless CDMA and Eudora voice attach.Last updated: 1998-04-29
vocoding
vocoderVoD
video on demandvoice mail
Any system for sending, storing and retrieving audio messages, like a telephone answering machine.
A voice mailbox is typically associated with a telephone number or extension. When the number is called and the line is busy or not answered, the caller hears a message left by the owner and is given instructions for leaving a message or other available options, such as paging the individual or being transferred to an operator. The owner of a mailbox can change the outgoing message or listen to incoming messages after entering a PIN. Members of a voice mail system can generally forward or broadcast messages to other members' boxes. The experience of two people trying to reach other by telephone but always reaching each other's voice mail is referred to as "(tele)phone tag".Last updated: 1996-11-03
voice-net
Hackish way of referring to the plain old telephone system, comparing it to a digital network. Usenet sig blocks sometimes include the sender's telephone number next to a "Voice:" or "Voice-Net:" header; variants of this are "Voicenet" and "V-Net". Compare paper-net, snail-mail. [Jargon File]Last updated: 1995-02-16
Voice over IP
(VoIP) Any technology providing voice telephony services over IP, including CODECs, streaming protocols and session control. The major advantage of VoIP is lower cost, by avoiding dedicated voice circuits.
Currently VoIP is being deployed on internal corporate networks, and, via the Internet, for low cost (and low quality) international calls. It is also used for telephony applications such as voice and fax mail. The ITU standard is H.323, which is a whole suite of protocols, while the IETF has developed the much simpler SIP to solve the session control problem and MGCP/Megaco to solve the gateway problem.Last updated: 2003-11-30
voice recognition
speech recognitionVoIP
Voice over IPvolatile
<storage>
2. See non-volatile storage.
Last updated: 1997-06-05
volatile memory
non-volatile storagevolatile storage
non-volatile storagevolatile variable
A variable in a computer program which can be modified by processes other than the program. For example, a variable that stores the value of a timer chip (either because it is located at the address of the hardware device or because it is updated on interrupts) needs to be volatile to be useful.
A static variable, on the other hand, maintains its value until the program changes it or it is no longer needed. In addition, volatile variables can be held in the stack whereas static variables are usually stored in a program's data segment.Last updated: 1995-05-17
voltage
(Or "potential difference", "electro-motive force" (EMF)) A quantity measured as a signed difference between two points in an electrical circuit which, when divided by the resistance in Ohms between those points, gives the current flowing between those points in Amperes, according to Ohm's Law. Voltage is expressed as a signed number of Volts (V). The voltage gradient in Volts per metre is proportional to the force on a charge.
Voltages are often given relative to "earth" or "ground" which is taken to be at zero Volts. A circuit's earth may or may not be electrically connected to the actual earth. The voltage between two points is also given by the charge present between those points in Coulombs divided by the capacitance in Farads. The capacitance in turn depends on the dielectric constant of the insulators present. Yet another law gives the voltage across a piece of circuit as its inductance in Henries multiplied by the rate of change of current flow through it in Amperes per second. A simple analogy likens voltage to the pressure of water in a pipe. Current is likened to the amount of water (charge) flowing per unit time.Last updated: 1995-12-04
Volume Table Of Contents
<storage>
(VTOC) /V-tock/ A special file on a disk, which contains a list of all the ordinary files on the disk and their addresses. Also called a directory.
The term is used mostly with large mainframe disk drives. Storage administrators will often refer to the VTOC to obtain information on the number of files stored on a disk.Last updated: 1997-04-15
von Neumann architecture
A computer architecture conceived by mathematician John von Neumann, which forms the core of nearly every computer system in use today (regardless of size). In contrast to a Turing machine, a von Neumann machine has a random-access memory (RAM) which means that each successive operation can read or write any memory location, independent of the location accessed by the previous operation.
A von Neumann machine also has a central processing unit (CPU) with one or more registers that hold data that are being operated on. The CPU has a set of built-in operations (its instruction set) that is far richer than with the Turing machine, e.g. adding two binary integers, or branching to another part of a program if the binary integer in some register is equal to zero (conditional branch). The CPU can interpret the contents of memory either as instructions or as data according to the fetch-execute cycle. Von Neumann considered parallel computers but recognized the problems of construction and hence settled for a sequential system. For this reason, parallel computers are sometimes referred to as non-von Neumann architectures. A von Neumann machine can compute the same class of functions as a universal Turing machine. [Reference? Was von Neumann's design, unlike Turing's, originally intended for physical implementation?] http://salem.mass.edu/~tevans/VonNeuma.htm.Last updated: 2003-05-16
von Neumann integer
The von Neumann integer N is a finite set with N elements which are the von Neumann integers 0 to N-1. Thus 0 = {} = {}
1 = {0} = {{}}
2 = {0, 1} = {{}, {{}}}
3 = {0, 1, 2} = {{}, {{}}, {{}, {{}}}}
...
The set of von Neumann integers is infinite, even though
each of its elements is finite.
[Origin of name?]
Last updated: 1995-03-30
von Neumann, John
John von Neumannvon Neumann machine
von Neumann architecturevon Neumann ordinal
An implementation of ordinals in set theory (e.g. Zermelo Fränkel set theory or ZFC). The von Neumann ordinal alpha is the well-ordered set containing just the ordinals "shorter" than alpha.
"Reasonable" set theories (like ZF) include Mostowski's Collapsing Theorem: any well-ordered set is isomorphic to a von Neumann ordinal. In really screwy theories (e.g. NFU -- New Foundations with Urelemente) this theorem is false. The finite von Neumann ordinals are the von Neumann integers.Last updated: 1995-03-30
voodoo programming
<jargon>
(From George Bush's "voodoo economics") The use by guess or cookbook of an obscure or hairy system, feature, or algorithm that one does not truly understand. The implication is that the technique may not work, and if it doesn't, one will never know why. Almost synonymous with black magic, except that black magic typically isn't documented and *nobody* understands it.
Compare magic, deep magic, heavy wizardry, rain dance, cargo cult programming, wave a dead chicken. [Jargon File]Last updated: 1995-03-10
Voronoi diagram
(Or "Voronoi tessellation", "Voronoi decomposition", "Dirichlet tessellation", After Georgy Feodosevich Voronoy) For a set S of points in a Euclidean space, the partition Vor(S) of the plane into the voronoi polygons associated with the members of S, where each polygon is defined by the set of points nearer to some given point in S than to any other point in S.
The Voronoi diagram is the dual of the Delaunay triangulation of S.Last updated: 2008-04-18
Voronoi polygon
For a member s of a set S of points in a Euclidean space, the locus of points in the plane that are closer to s than to any other member of S.
Last updated: 1997-08-03
VOS
An operating system used in Stratus computers.
See also FTX. [Details?]Last updated: 1998-07-06
Voters Telecommunications Watch
<body>
(VTW) A non-profit organisation based in New York, founded by Shabbir J. Safdar to protect the rights of Internet users. The VTW has actively opposed regulation of encryption and restrictions on Internet free speech. VTW created the animated "Free Speech" fireworks icon that has been displayed on many web pages since June 12, 1996, the day that a three-judge panel in Philadelphia ruled the CDA unconstitutional.
http://vtw.org.Last updated: 1996-11-03
voxel
<jargon>
(By analogy with "pixel") Volume element.
The smallest distinguishable box-shaped part of a three-dimensional space. A particular voxel will be identified by the x, y and z coordinates of one of its eight corners, or perhaps its centre. The term is used in three dimensional modelling.Last updated: 1995-03-10
Nearby terms:
VMS ♦ VM/SP ♦ VM/XA ♦ vn ♦ vocoder ♦ vocoding ♦ VoD ♦ voice mail ♦ voice-net
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