Page 323 - Electrical Engineering Dictionary

operators, such as mutation and crossover, Jacobian is defined for an arbitrary manipula-
are applied to the set of solutions. The “good- tor and depends on its geometric parameters
ness” metric is applied again and the algo- (more precisely, Denavit–Hartenberg param-
rithm iterates until all solutions meet certain eters). See also analytical Jacobian.
criteria or a specific number of iterations has
been completed. See also optimization. geometric radian center frequency the
logarithmic radian center frequency, it is the
genlock a shortened term for “generator logarithmic mid-point between the higher
lock,” meaning that one sync generator sys- (ω H ) and lower (ω H ) band edges, expressed
tem is locked to another. When video sys- in radians/second. The band edges are usu-
tems are genlocked, sync and burst informa- ally defined as the highest and lowest fre-
tion is the same for both systems. quencies within a contiguous band of inter-
est at which the loss equals L Amax , the max-
geodesic lens a lens composed of cir- imum attenuation loss across the band.
cularity symmetric spherical depression (or √
ω OG = ω H · ω L
dimples) in the surface of a thin-film waveg-
uide. In this type of lens, light waves are con- or
fined in the waveguide and follow the longer log (ω H ) + log (ω L )
10
10
10
curved path through the lens region. Waves log (ω OG ) = 2
propagating near the center of the lens travel
a longer path than waves near the edge, mod-
geometric theory of diffraction a cor-
ifying the wave front so that focusing can
rection to geometrical optics that includes
occur.
diffracted fields due to corners or edges
and accounts for energy diffracted into the
geometric distribution a discrete proba-
shadow region.
bility density function of a random variable
x that has the form geometric transformation transforms
the pixel co-ordinates of an image to effect
k
p{x = k}= p(1 − p) k = 0, 1, 2,.... a change in the spatial relationships of ele-
ments in the image. The change often takes
This is the probability that k independent tri- the form of a stretching or warping of the
als, each with probability of success p and image.
failure 1 − p, fail before one succeeds. See
also probability density function. geometrical optics a high-frequency
technique using ray tracing for tubes of rays
geometric Jacobian the Jacobian (or todetermineincident, reflected, andrefracted
more precisely the Jacobian matrix, but fields. Most useful in real media when the
roboticists usually shorten it to simply Jaco- wave amplitude varies slowly compared to
bian) is a mapping from velocities in joint the wavelength.
space (generalized velocities) to velocities
in Cartesian space. This mapping is writ- geosynchronous orbit an orbit 22,753
ten in the form v = J(q)˙q where v is a miles above the earth in which an object will
six-dimensional vector of linear and angu- orbit the earth once every 24 hours above the
lar velocities of the end-effector and ˙q is equator and will appear to be stationary from
a vector of generalized velocities ˙q(t) = the earth’s surface.
T
[˙q 1 (t), ˙q 2 (t),..., ˙q n (t)] . The Jacobian has
dimensions 6 × n. All points in which the geothermal energy thermal energy in the
Jacobian is not invertible are called singular- form of hot water and steam in the earth’s
ities of the mechanism or singularities. The crust.

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2000 by CRC Press LLC