154,966 research outputs found
Comparison of Three Stiffness Testers
Stiffness is defined and some of the factors affecting stiffness are given. Also, the underlying principles upon which most stiffness testers are based are given.
Three of the commonly used stiffness instruments are used for this comparison study. They are: Gurley, Smith-Taber, and the Clark. The correlation between the instruments is determined and the stiffness range that each instrument is best suited for is noted
Ionization experiment
Mariner space probe ionization chamber and Geiger counter experiments on galactic radiation entering solar syste
Near real-time stereo vision system
The apparatus for a near real-time stereo vision system for use with a robotic vehicle is described. The system is comprised of two cameras mounted on three-axis rotation platforms, image-processing boards, a CPU, and specialized stereo vision algorithms. Bandpass-filtered image pyramids are computed, stereo matching is performed by least-squares correlation, and confidence ranges are estimated by means of Bayes' theorem. In particular, Laplacian image pyramids are built and disparity maps are produced from the 60 x 64 level of the pyramids at rates of up to 2 seconds per image pair. The first autonomous cross-country robotic traverses (of up to 100 meters) have been achieved using the stereo vision system of the present invention with all computing done onboard the vehicle. The overall approach disclosed herein provides a unifying paradigm for practical domain-independent stereo ranging
Identification, definition and mapping of terrestrial ecosystems in interior Alaska
The author has identified the following significant results. The vegetation map in preparation at the time of the last report was refined and labeled. This map is presented as an indication of the spatial and classificatory detail possible from interpretations of enlarged ERTS-1 color photographs. Using this map, areas covered by the several vegetation types characterized by white spruce were determined by planimetry. A 1:63,360 scale land use map of the Juneau area was drawn. This map incorporates the land use classification system now under development by the U.S. Geological Survey. The ERTS-1 images used in making the Juneau map were used to determine changes in surface area of the terminal zones of advancing and receding glaciers, the Taku, Norris, and Mendenhall. A new 1:63,360 scale land use map of the Bonanza Creek Experimental Forest and vicinity was drawn. Several excellent new sciences of test areas were received from NASA in color-infrared transparency format. These are being used for making photographic prints for analysis and mapping according to procedures outlined in this report
Complex wave function, Chiral spin order parameter and Phase Problem
We study the two dimensional Hubbard model by use of the ground state
algorithm in the Monte Carlo simulation. We employ complex wave functions as
trial function in order to have a close look at properties such as chiral spin
order (SO) and flux phase. For half filling, a particle-hole
transformation leads to sum rules with respect to the Green's functions for a
certain choice of a set of wave functions. It is then analytically shown that
the sum rules lead to the absence of the SO. Upon doping, we are
confronted with the sign problem, which in our case %ch appears as a ``phase
problem" due to the phase of the Monte Carlo weights. The average of the phase
shows an exponential decay as a function of inverse temperature similarly to
that of sign by Loh Jr. et. al. . We compare the numerical results with those
of exact numerical calculations.Comment: 28 pages, 9 figures(hard copy will be available upon request
Why U.S. managers might be more short-run oriented than the Japanese
A consideration of whether differences between U.S. and Japanese business practices have led the Japanese to focus on longer-run goals than we do.Japan ; Management
Extent and character of early tertiary penetrative deformation, Sonora, Northwest Mexico
Reconnaissance field work has led to the recognition of extensive Early Tertiary gneiss and schist which are distinguished by weakly developed to highly conspicous northeast to east-trending stretching lineation commonly accompanied by low-dipping foliation. This structural fabric has been imposed on Precambrian to Paleogene rocks. Regionally, minimum ages of deformation are based upon interpreted U-Pb isotopic ages from suites of cogenetic zircon from the Paleogene orthogneiss. Locally, the interpreted ages indicate that ductile deformation continued as late as Oligocene (Anderson and others, 1980; Silver and Anderson, 1984). The consistency of the deformational style is such that, although considerable variation in intensity exists, the fabric can be recognized and correlated in rocks away from the Paleogene orthogneiss
Is the rust belt's revival real?
An exploration of the causes of the improved performance of the Great Lakes region in the 1990-91 recession relative to past economic downturns, and a prediction that the mild levels and duration of employment loss posted here during the past two years cannot be assured to continue in the next recession.Great Lakes
The shuttle glow: A program to study the ram-induced phenomena
In January 1984, a proposal was submitted to NASA Headquarters entitled The Shuttle Glow: A Program to Determine the Physics of the Ram induced Phenomena. This proposal included the following elements in a shuttlebased experiment: (1) The use of a special flat generating surface 1 x 3 m on which the glow can be produced and observed. This surface will be maneuvered to vary the orientation of ram flow and of projected component of geomagnetic field. (2) Remotely mounted optical instruments to view the glowing layer on the plate. By scanning, the variation of radiance as a function of wavelength and standoff distance from the plate will be observed looking parallel to the plate. (3) The preferred location of the generating plate and in situ diagnostics is on the end of the Remote Manipulator System (RMS) arm
POLITICS OF PUBLIC SUPPORT OF RESEARCH AND EXTENSION
Research and Development/Tech Change/Emerging Technologies,
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