6,173 research outputs found
Air Force research in optical processing
Optical and optical electronic hybrid processing especially in the application area of image processing are emphasized. Real time pattern recognition processors for such airborne missions as target recognition, tracking, and terminal guidance are studied
Absolute optical flux observations of the 18 October 1967 total eclipse of the moon
Absolute optical flux observations of total moon eclipse on 18 October 196
Fundamental spectrophotometry of the major planets Progress report, 1 Jun. 1970 - 1 Feb. 1971
Spectrophotometry of Neptune, Uranus, and Plut
Micro-scale crease-and-fold apparatus
Crease and fold resistance of polymeric films and test equipment for determining mechanical properties is discussed. Components of equipment and method of operation are described. Illustration of test device is provided
Self-supported aluminum thin films produced by vacuum deposition process
Self-supported aluminum thin film is produced by vacuum depositing the film on a polyvinyl formal resin film and then removing the resin by radiant heating in the vacuum. The aluminum film can be used as soon as the resin is eliminated
JHK Imaging and Photometry of Low z QSOs and Radio Galaxy
We describe J,H,K deep imaging of 90 arcmin fields around 4 QSOs and one
Radio galaxy at redshifts in the range 0.06 to 0.30, and show their images,
luminosity profiles, and NIR 2-colour diagrams of objects. We find that the QSO
hosts are all resolved, and compare them with previous CCD images. The host
galaxy colours are consistent with old and young stellar populations at the QSO
redshift. The colours of nearby galaxies suggest that all the AGN live in
groups of generally smaller companion galaxies, mostly with evolved populations
at the same redshift. The two radio-loud objects live in richer cluster
environments than the others. Gissel population models indicate reddening in
the galaxies, star-forming regions, and possibly a systematic H-K offset. The
QSO luminosity profiles are complex and reveal some of their tidal disturbance
and star-formation history.Comment: 22 pages of text (latex), 2 tables )latex), and 15 figures
(postscript). Accepted for publication in AJ, February 1997. Also available
at http://www.dao.nrc.ca/DAO/SCIENCE/science.htm
Geometry of logarithmic strain measures in solid mechanics
We consider the two logarithmic strain measureswhich are isotropic invariants of the
Hencky strain tensor , and show that they can be uniquely characterized
by purely geometric methods based on the geodesic distance on the general
linear group . Here, is the deformation gradient,
is the right Biot-stretch tensor, denotes the principal
matrix logarithm, is the Frobenius matrix norm, is the
trace operator and is the -dimensional deviator of
. This characterization identifies the Hencky (or
true) strain tensor as the natural nonlinear extension of the linear
(infinitesimal) strain tensor , which is the
symmetric part of the displacement gradient , and reveals a close
geometric relation between the classical quadratic isotropic energy potential
in
linear elasticity and the geometrically nonlinear quadratic isotropic Hencky
energywhere
is the shear modulus and denotes the bulk modulus. Our deduction
involves a new fundamental logarithmic minimization property of the orthogonal
polar factor , where is the polar decomposition of . We also
contrast our approach with prior attempts to establish the logarithmic Hencky
strain tensor directly as the preferred strain tensor in nonlinear isotropic
elasticity
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