dictionary of multimedia and internet applications: a guide for developers and users. francis botto

Print ISBN 0-471-98624-0 Online ISBN 0-470-84178-8

Y 1. A horizontal dimension of a coordinate in a two- or three-dimensional vector coordinate representation. The value may be absolute, measured from the origin [0, 0] or relative such as [X +X , Y +Y ]. A 2-D 0 1 0 1 computer image or animation might be stored and generated using absolute or relative coordinates that include X (horizontal) and Y (vertical) dimensions. Authentic 2-D animations depend upon matrix multiplication where sets of coordinates are multiplied by a transformation matrix. 2-D vectors [X,Y] might be exchanged for homogeneous vector coordinates [X,Y,H]. The homogeneous dimension (H) is added to accommodate a three-row transformation matrix, so increasing the number of possible 2-D transformations. (See 3-D.) 2. A luminance component of video signal.

Y2K (year 2000) A term used to describe the year 2000. The lead up to the

end of the millennium sees numerous IT systems being renovated to accom-modate the need for date stamping using the year 2000 and its increments. Many non-compliant Y2K IT systems were created decades ago, when little consideration was given to the future.

Yamaha A large company engaged in consumer electronics, computers, music and more.

Y-axis A horizontal axis on a graph or drawing.

Y-dimension A horizontal measurement that might be absolute or relative,

in a 2-D or 3-D coordinate.

(See 2-D and 3-D.)

Yellow Alarm An alarm state which forms part of the T1 circuit specifi-cation. (See T1.) The Yellow Alarm is activated by:

● the receipt of a Red Alarm signal ● severe burst traffic.

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Yellow Book

Yellow Book An alternative name for the CD-ROM physical format created by Philips and Sony. Later, standard file structures came about as a result of industry cooperation in 1985 by way of the High Sierra Group (HSG) standard. This was built upon by ISO to become ISO 9660. A universal distribution medium based on Compact Disc, CD-ROM was the first viable multimedia distribution medium.

(See CD-ROM, CD-ROM data block and DVD.)

YMODEM A protocol that supports data transfer using 1024 byte blocks, also referred to as XMODEM 1K.

YMODEM G A protocol which transmits a complete file before an acknowledge signal is received. It is intended for modem devices that have built-in error detection and correction.

YUV A collective name given to the luminance (Y) and chrominance components of a video signal.

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