98,002 research outputs found
Logistics hardware and services control system
Software system permits onsite direct control of logistics operations, which include spare parts, initial installation, tool control, and repairable parts status and control, through all facets of operations. System integrates logistics actions and controls receipts, issues, loans, repairs, fabrications, and modifications and assets in predicting and allocating logistics parts and services effectively
Computer program documentation for the pasture/range condition assessment processor
The processor which drives for the RANGE software allows the user to analyze LANDSAT data containing pasture and rangeland. Analysis includes mapping, generating statistics, calculating vegetative indexes, and plotting vegetative indexes. Routines for using the processor are given. A flow diagram is included
Geologic application of thermal-inertia mapping from satellite
The author has identified the following significant results. Two night-time thermal images of the Powder River Basin, Wyoming distinctly show a major thermal feature. This feature is substantially coincident with a drainage divide and the southward facing slope appears cooler, suggesting a lower thermal inertia. An initial examination of regional geologic maps provides no clear evidence to suggest what type of geologic feature or structure may be present, although it can be noted that its northeastern end passes directly through Lead, South Dakota where the Homestake Gold Mine is located
Experimental constraints on the polarizabilities of the 6s^2 1S0 and 6s6p 3P0 states of Yb
We utilize accurate experimental data available in the literature to yield
bounds on the polarizabilities of the ground and first excited states of atomic
Yb. For the 6s^2 1S0 ground state, we find the polarizability alpha to be
constrained to 134.4<alpha<144.2 in atomic units, while for the 6s6p 3P0
excited state we find 280.1<alpha<289.9. The uncertainty in each of these
values is 1.0. These constraints provide a valuable check for ab initio and
semi-empirical methods used to compute polarizabilities and other related
properties in Yb.Comment: 7 pages, 1 figur
The Hetu'u Global Network: Measuring the Distance to the Sun Using the June 5th/6th Transit of Venus
In the spirit of historic astronomical endeavors, we invited school groups
across the globe to collaborate in a solar distance measurement using the rare
June 5/6th transit of Venus. In total, we recruited 19 school groups spread
over 6 continents and 10 countries to participate in our Hetu'u Global Network.
Applying the methods of French astronomer Joseph-Nicolas Delisle, we used
individual second and third Venus-Sun contact times to calculate the distance
to the Sun. Ten of the sites in our network had amiable weather; 8 of which
measured second contact and 5 of which measured third contact leading to
consistent solar distance measurements of 152+/-30 million km and 163+/-30
million km respectively. The distance to the Sun at the time of the transit was
152.25 million km; therefore, our measurements are also consistent within
1sigma of the known value. The goal of our international school group network
was to inspire the next generation of scientists using the excitement and
accessibility of a rare astronomical event. In the process, we connected
hundreds of participating students representing a diverse, multi-cultural group
with differing political, economic, and racial backgrounds.Comment: 19 pages; 7 Figures; 1 Table; Accepted for publication in Astronomy
Education Review (AER) For more information see
http://www.das.uchile.cl/~drodrigu/easter/index_en.htm
Identification of nonlinear vibrating structures: Part I -- Formulation
A self-starting multistage, time-domain procedure is presented for the identification of nonlinear, multi-degree-of-freedom systems undergoing free oscillations or subjected to arbitrary direct force excitations and/or nonuniform support motions. Recursive least-squares parameter estimation methods combined with nonparametric identification techniques are used to represent, with sufficient accuracy, the identified system in a form that allows the convenient prediction of its transient response under excitations that differ from the test signals. The utility of this procedure is demonstrated in a companion paper
Identification of nonlinear vibrating structures: Part II -- Applications
A time-domain procedure for the identification of nonlinear vibrating structures, presented in a companion paper, is applied to a "calibration" problem which incorporates realistic test situations and nonlinear structural characteristics widely encountered in the applied mechanics field. The "data" set is analyzed to develop suitable, approximate nonlinear system representations. Subsequently, a "validation" test is conducted to demonstrate the range of validity of the method under discussion. It is shown that the procedure furnishes a convenient means for constructing reduced-order nonlinear nonparametric mathematical models of reasonably high fidelity in regard to reproducing the response of the test article under dynamic loads that differ from the identification test loads
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