Page 292 - Electrical Engineering Dictionary

Flynn’s Taxonomy
Single-Data Stream Multiple-Data Stream
von Neumann architecture/uniprocessors Systolic processors
Single-Instruction Stream
RISC Wavefront processors
Pipelined architectures Dataflow processors
Multiple-Instruction Stream
Very long instruction word processors Transputers

flyback inductor See flyback converter. focal length distance from a lens or mirror
at which an input family of parallel light rays
will be brought to a focus.
flybacktransformer Seeflybackconverter.
focus the position of the plane of best fo-
cus of the optical system relative to some ref-
flying head disk a disk storage device that
erence plane, such as the top surface of the
uses a read/write head unit “flying” over (i.e.,
resist, measured along the optical axis (i.e.,
very closely above) the disk surface on a thin
perpendicular to the plane of best focus).
air bearing. Used e.g., in “Winchester” disks
(a sealed “hard disk”). This is in contrast to,
focus of attention the center of the region
e.g., floppy disks, where the head unit is ac-
detected by a visual attention mechanism,
tually in physical contact with the disk when
which is the first stage of a pattern recog-
reading or writing. See also disk head.
nition system that is aimed to detect regions
where a target object is likely to be found.
Flynn’s taxonomy a classification system
that organizes computer processor types as focus of expansion (1) in optical flow
either single-instruction stream or multiple- computation, the point into which the veloc-
instruction stream and either single-data ity field lines of a translating object converge.
stream or multiple-data stream. The four (2) the point in an image from which
resultant types of computer processors are feature points appear to be diverging when
known as SISD, MISD, SIMD, and MIMD the camera is moving forward or objects are
(see table below). Due to Michael J. Flynn moving toward the camera.
(1966).
focus-exposure matrix the variation of
flywheel a heavy wheel placed on the shaft linewidth (and possibly other parameters) as
of an electrical machine for storing kinetic a function of both focus and exposure energy.
energy. A flywheel may be used to help damp The data is typically plotted as linewidth
speed transients or, to help deliver energy to versus focus for different exposure energies,
impact loads such as a punch press. called the Bossung plot.

focused ion beam (FIB) a lithography
FM See frequency modulation.
technique similar to electron beam lithog-
raphy in which a stream of charged ions is
FMS See flexible manufacturing systems. raster-scanned to produce an image in a re-
sist.

FM sound a carrier wave whose instanta- focuser a focusing electrode for an elec-
neous frequency is varied by an amount pro- tron steam in a vacuum tube.
portional to the instantaneous amplitude of
the sound input modulating signal. FOH See first order hold.

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