197,968 research outputs found

    Model verification of large structural systems

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    A methodology was formulated, and a general computer code implemented for processing sinusoidal vibration test data to simultaneously make adjustments to a prior mathematical model of a large structural system, and resolve measured response data to obtain a set of orthogonal modes representative of the test model. The derivation of estimator equations is shown along with example problems. A method for improving the prior analytic model is included

    The vibrational predissociation spectroscopy of hydrogen cluster ions

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    The first infrared spectra of protonated hydrogen clusters in the gas phase have been observed. Predissociation spectra were taken with a tandem mass spectrometer: mass selected hydrogen cluster ions were irradiated inside a rf ion trap by a tunable infrared laser, and the fragment ions created by photodissociation of the clusters were mass selected and detected. Spectra for each product channel were measured by counting fragment ions as a function of laser frequency. Low resolution spectra (Deltanu=10 cm^−1) in the region from 3800 to 4200 cm^−1 were observed for the ions H + 5, H + 7, and H + 9 at 3910, 3980, and 4020 cm−1, respectively. A band was also observed for H + 5 at 3532 cm^−1. No rotational structure was resolved. The frequencies of the band maxima agree well with the frequencies predicted by previous ab initio calculations for the highest modes

    Cow-Calf Producer Perceptions Regarding Individual Animal Traceability

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    This study provides valuable insights into cow-calf producer voluntary participation in the National Animal Identification System and producers’ perceptions of several issues critically impacting the success of voluntary traceability systems. Cow-calf producers believe that the most important issues to the U.S. beef industry in designing a national, individual animal traceability system are monitoring/managing disease, maintaining current foreign markets, accessing foreign markets, and increasing consumer confidence. Furthermore, producers are concerned with cost, liability, reliability of technology, failure of system to meet stated goals, and confidentiality of information associated with these systems.animal traceability, cow-calf, National Animal Identification System, voluntary adoption, Agribusiness, Community/Rural/Urban Development, Crop Production/Industries, Farm Management, Labor and Human Capital, Land Economics/Use, Livestock Production/Industries, Production Economics, Research and Development/Tech Change/Emerging Technologies, Q12, Q18, R38,

    A semantic-based system for querying personal digital libraries

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    This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-540-28640-0_4. Copyright @ Springer 2004.The decreasing cost and the increasing availability of new technologies is enabling people to create their own digital libraries. One of the main topic in personal digital libraries is allowing people to select interesting information among all the different digital formats available today (pdf, html, tiff, etc.). Moreover the increasing availability of these on-line libraries, as well as the advent of the so called Semantic Web [1], is raising the demand for converting paper documents into digital, possibly semantically annotated, documents. These motivations drove us to design a new system which could enable the user to interact and query documents independently from the digital formats in which they are represented. In order to achieve this independence from the format we consider all the digital documents contained in a digital library as images. Our system tries to automatically detect the layout of the digital documents and recognize the geometric regions of interest. All the extracted information is then encoded with respect to a reference ontology, so that the user can query his digital library by typing free text or browsing the ontology

    Computer programs for prediction of structural vibrations due to fluctuating pressure environments. Volume 1 - Theoretical analyses Final report

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    Theoretical analyses for computer program to calculate random vibrations of reinforced rectangular cylindrical panels in fluctuating pressure environmen

    Shuttle system ascent aerodynamic and plume heating

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    The shuttle program provided a challenge to the aerothermodynamicist due to the complexity of the flow field around the vehicle during ascent, since the configuration causes multiple shock interactions between the elements. Wind tunnel tests provided data for the prediction of the ascent design heating environment which involves both plume and aerodynamic heating phenomena. The approach for the heating methodology based on ground test firings and the use of the wind tunnel data to formulate the math models is discussed
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