recloser
a self-contained device placed on
distribution lines that senses line currents and
opens on overcurrent. Reclosing is employed
to reenergize the protected line segment in
the case of temporary faults. Reclosers have
the capability for fast tripping for fuse sav-
ing, and slow tripping to allow sectionalizing
fuse operation for faults on laterals. The re-
closer will retrip on permanent faults and go
on to lockout. Reclosers are suitable for pole
mounting on overhead lines.
reclosing relay
an auxiliary relay that ini-
tiates circuit breaker closing in a set sequence
following fault clearing. Reclosing relays are
typically employed on overhead lines where
a high proportion of the faults are temporary.
recoil permeability
the average slope of
the minor hysteresis loop, which is roughly
the slope of the major hysteresis loop at zero
applied field (
H ), and is most often used to
determine the effect of applying and remov-
ing a demagnetizing field to and from a mag-
netic material.
recombination
the process in which an
electron neutralizes a hole. Sometimes this
process causes light emission (i.e., through
radiative recombination), and sometimes it
doesn’t (i.e., through nonradiative recombi-
nation).
recombination X-ray laser
an X-ray
laser made by gain from an inverted popu-
lation where the upper level is inverted due
to recombining ions and electrons.
reconstruction
the process of forming a
3-D image from a set of 2-D projection im-
ages. Also applies to the formation of a 2-
D image from 1-D projections. See
image
reconstruction
,
tomography
and
computed
tomography.
reconstruction from marker
in a binary
image, this is the operation extracting all con-
nected components having a non-empty in-
tersection with a marker. This operation can
be generalized to gray-level images by a mor-
phological operator applying such a recon-
struction on the gray-level slices of the im-
age.
record
unit of data, corresponding to a
block, sector, etc., on a magnetic disk, mag-
netic tape, or other similar I/O medium.
recording code
a line code optimized for
recording systems. See also
line code
.
recording density
number of bits stored
per linear inch on a disk track. In general, the
same number of bits are stored on each track,
so that the density increases as one moves
from the outermost to the innermost track.
recovery
action that restores the state of a
process to an earlier configuration after it has
been determined that the system has entered a
state which does not correspond to functional
behavior. For overall functional behavior, the
states of all processes should be restored in a
manner consistent with each other, and with
the conditions within communication links or
message channels.
rectangle detection
the detection of rect-
angle shapes, often by searching for cor-
ner signals, or from straight edges present
in an image. Rectangle detection is impor-
tant when locating machined parts in images,
e.g., prior to robot assembly tasks. See also
polygon detection
and square detection.
rectangular cavity
a section of rectangu-
lar waveguide closed on both ends by con-
ducting plates.
rectangular window
(1) in finite impulse
response (FIR) filter design, the rectangu-
lar window constituting the most straightfor-
ward window function used usually as a ref-
erence in studying other window functions.
It is defined as 1 within an even interval cen-
tered at the origin and 0 elsewhere.
(2) in image processing, an rectangular
area centered at a pixel under consideration.
c
2000 by CRC Press LLC