25,171 research outputs found
Web Based Semantic Communities ā Who, How and Why We Might Want Them in the First Place
This paper describes an investigation undertaken as part of the FicNet Human-Computer Interaction project into the online amateur fiction community. By working with the community to determine current practices and areas of concern we consider how future technologies such as the semantic web might be used to design applications to support the community. As a first step in this process we gathered opinions both from members of the community and from those outside the community who had come into contact with it. Taking this information we consider the community as it is and what it might become
Bringing Communities to the Semantic Web and the Semantic Web to Communities
In this paper we consider the types of community networks that are most often codified within the Semantic Web. We propose the recognition of a new structure which fulfils the definition of community used outside the SemanticWeb. We argue that the properties inherent in a community allow additional processing to be done with the described relationships existing between entities within the community network. Taking an existing online community as a case study we describe the ontologies and applications that we developed to support this community in the Semantic Web environment and discuss what lessons can be learnt from this exercise and applied in more general settings
Freedom and Restraint: Tags, Vocabularies and Ontologies
The benefit of metadata is widely recognized. However, the nature of that information and the method of production remains a topic of some debate. This division is most noticeable between those who believe in āfree taggingā, and those who prefer the more formal construction of an ontology to define both the vocabulary of the domain and the relationships between the concepts within it. Looking at the community surrounding online amateur authors and the descriptive metadata they have developed over the last thirty years we consider what we can learn from a mature but amateur tagging community. This paper considers how these two systems might be used together to add the easy usability of free tagging to ontology descriptions and the conceptual richness of ontologies to free tags
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Converting three-space matrices to equivalent six-space matrices for Delone scalars in S6.
The transformations from the primitive cells of the centered Bravais lattices to the corresponding centered cells have conventionally been listed as three-by-three matrices that transform three-space lattice vectors. Using those three-by-three matrices when working in the six-dimensional space of lattices represented as Selling scalars as used in Delone (Delaunay) reduction, one could transform to the three-space representation, apply the three-by-three matrices and then back-transform to the six-space representation, but it is much simpler to have the equivalent six-by-six matrices and apply them directly. The general form of the transformation from the three-space matrix to the corresponding matrix operating on Selling scalars (expressed in space S6) is derived, and the particular S6matrices for the centered Delone types are listed. (Note: in his later publications, Boris Delaunay used the Russian version of his surname, Delone.)
Seasonal Shoot-Feeding by \u3ci\u3eTomicus Piniperda\u3c/i\u3e (Coleoptera: Scolytidae) in Michigan
Seasonal shoot-feeding by Tomicus piniperda (L.) was monitored at 2Ā week intervals on 15 Scotch pine, Pinus sylvestris L., trees from 8 April through 16 November 1994 in southern Michigan. All shoots that showed evidence of T. piniperda attack were removed every two weeks. In 1994, initial spring flight of T. piniperda began on 22 March. At least two live T. piniperda adults were found on the 15 trees on each sampling date from 8 April through 1 November 1994. In addition, at least one freshly attacked, beetle- free shoot was found on each sampling date except for 1 November. The greatest numbers of newly attacked shoots, with or without adults present, were found from mid-June through mid-August. All adults found in April and May were likely parent adults, while those from June onward were primarily brood adults. Therefore, at all times of the year, live T. piniperda adults can be found on live pine trees, either feeding in the shoots or overwintering at the base of the trunk. Implications of these findings are provided in light of the US federal quarantine on T. piniperda
Mach-Zehnder optical configuration with Brewster window and two quarter-wave plates
Configuration is improvement because of the following: It provides higher efficiency. It reduces or eliminates feedthrough of untranslated local oscillator, which would produce a beat signal at shifted frequency of translator. When used without translator and with low-power detector, telescope secondary mirror reflects portion of output to local oscillator
Analysis of airborne imaging spectrometer data for the Ruby Mountains, Montana, by use of absorption-band-depth images
Airborne Imaging Spectrometer-1 (AIS-1) data were obtained for an area of amphibolite grade metamorphic rocks that have moderate rangeland vegetation cover. Although rock exposures are sparse and patchy at this site, soils are visible through the vegetation and typically comprise 20 to 30 percent of the surface area. Channel averaged low band depth images for diagnostic soil rock absorption bands. Sets of three such images were combined to produce color composite band depth images. This relative simple approach did not require extensive calibration efforts and was effective for discerning a number of spectrally distinctive rocks and soils, including soils having high talc concentrations. The results show that the high spectral and spatial resolution of AIS-1 and future sensors hold considerable promise for mapping mineral variations in soil, even in moderately vegetated areas
The joint large-scale foreground-CMB posteriors of the 3-year WMAP data
Using a Gibbs sampling algorithm for joint CMB estimation and component
separation, we compute the large-scale CMB and foreground posteriors of the
3-yr WMAP temperature data. Our parametric data model includes the cosmological
CMB signal and instrumental noise, a single power law foreground component with
free amplitude and spectral index for each pixel, a thermal dust template with
a single free overall amplitude, and free monopoles and dipoles at each
frequency. This simple model yields a surprisingly good fit to the data over
the full frequency range from 23 to 94 GHz. We obtain a new estimate of the CMB
sky signal and power spectrum, and a new foreground model, including a
measurement of the effective spectral index over the high-latitude sky. A
particularly significant result is the detection of a common spurious offset in
all frequency bands of ~ -13muK, as well as a dipole in the V-band data.
Correcting for these is essential when determining the effective spectral index
of the foregrounds. We find that our new foreground model is in good agreement
with template-based model presented by the WMAP team, but not with their MEM
reconstruction. We believe the latter may be at least partially compromised by
the residual offsets and dipoles in the data. Fortunately, the CMB power
spectrum is not significantly affected by these issues, as our new spectrum is
in excellent agreement with that published by the WMAP team. The corresponding
cosmological parameters are also virtually unchanged.Comment: 5 pages, 4 figures, submitted to ApJL. Background data are available
at http://www.astro.uio.no/~hke under the Research ta
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