7,615 research outputs found
Shape of Deconstruction
We construct a six-dimensional Maxwell theory using a latticized extra space,
the continuum limit of which is a shifted torus recently discussed by Dienes.
This toy model exhibits the correspondence between continuum theory and
discrete theory, and give a geometrical insight to theory-space model building.Comment: 10 pages, 2 figures, RevTeX4. a citation adde
Effects of scale in predicting global structural response
Analytical techniques for scale-up effects were reviewed. The advantages and limitations of applying the principles of similitude to composite structures is summarized and illustrated by simple examples. An analytical procedure was formulated to design scale models of an axially compressed composite cylinder. A building-block approach was outlined where each structural detail is analyzed independently and the probable failure sequence of a selected component is predicted, taking into account load redistribution subsequent to first element failure. Details of this building-block approach are under development
Kinetic response of ionospheric ions to onset of auroral electric fields
Examination of the exact analytic solution of a kinetic model of collisional interaction of ionospheric fions with atmospheric neutrals in the Bhatnagar-Gross-Krook approximation, shows that the onset of intense auroral electric fields in the topside ionosphere can produce the following kinetic effects: (1) heat the bulk ionospheric ions to approximately 2 eV, thus driving them up to higher altitudes where they can be subjected to collisionless plasma processes; (2) produce a nonMaxwellian superthermal tail in the distribution function; and (3) cause the ion distribution function to be anisotropic with respect to the magnetic field with the perpendicular average thermal energy exceeding the parallel thermal energy
Timber type separability in Southeastern United States on LANDSAT-1 MSS data
A quantitative, computer-aided study was made on the spectral separability of timber types and condition classes in the Southeastern United States, using LANDSAT-1 multispectral scanner data. It was concluded that LANDSAT-1 could be used effectively to discriminate the gross forest features of softwood, hardwood, and regeneration. The only significant detectable age difference would be between an established forest versus a young (or denuded) forest. The red or near infrared bands would be better for discrimination; phenological early and late spring data would be better than winter. And a temporal analysis would be superior to single-season analysis. Lastly, two spectral bands would be most cost effective for computer analysis. The study site was Sam Houston National Forest of East Texas, a typical forest in the Flatwoods Zone, Southern Region, U. S. Forest Service
Using the Annotated Bibliography as a Resource for Indicative Summarization
We report on a language resource consisting of 2000 annotated bibliography
entries, which is being analyzed as part of our research on indicative document
summarization. We show how annotated bibliographies cover certain aspects of
summarization that have not been well-covered by other summary corpora, and
motivate why they constitute an important form to study for information
retrieval. We detail our methodology for collecting the corpus, and overview
our document feature markup that we introduced to facilitate summary analysis.
We present the characteristics of the corpus, methods of collection, and show
its use in finding the distribution of types of information included in
indicative summaries and their relative ordering within the summaries.Comment: 8 pages, 3 figure
Fermion spectrum and localization on kinks in a deconstructed dimension
We study the deconstructed scalar theory having nonlinear interactions and
being renormalizable. It is shown that the kink-like configurations exist in
such models. The possible forms of Yukawa coupling are considered. We find the
degeneracy in mass spectrum of fermions coupled to the nontrivial scalar
configuration.Comment: 19pages, 39figures, revised versio
Kondo Effect in Fermi Systems with a Gap: A Renormalization Group Study
We present the results of a Wilson Renormalization Group study of the
single-impurity Kondo and Anderson models in a system with a gap in the
conduction electron spectrum. The behavior of the impurity susceptibility and
the zero-frequency response function, are discussed in the
cases with and without particle-hole symmetry. In addition, for the asymmetric
Anderson model the correlation functions, , are computed.Comment: 10 pages, 10 figure
Resources for Evaluation of Summarization Techniques
We report on two corpora to be used in the evaluation of component systems
for the tasks of (1) linear segmentation of text and (2) summary-directed
sentence extraction. We present characteristics of the corpora, methods used in
the collection of user judgments, and an overview of the application of the
corpora to evaluating the component system. Finally, we discuss the problems
and issues with construction of the test set which apply broadly to the
construction of evaluation resources for language technologies.Comment: LaTeX source, 5 pages, US Letter, uses lrec98.st
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