12,619 research outputs found
Hardy-Sobolev-Maz'ya inequalities for arbitrary domains
We prove a Hardy-Sobolev-Maz'ya inequality for arbitrary domains
\Omega\subset\R^N with a constant depending only on the dimension N\geq 3. In
particular, for convex domains this settles a conjecture by Filippas, Maz'ya
and Tertikas. As an application we derive Hardy-Lieb-Thirring inequalities for
eigenvalues of Schr\"odinger operators on domains.Comment: 19 page
The sharp constant in the Hardy-Sobolev-Maz'ya inequality in the three dimensional upper half-space
It is shown that the sharp constant in the Hardy-Sobolev-Maz'ya inequality on
the three dimensional upper half space is given by the Sobolev constant. This
is achieved by a duality argument relating the problem to a
Hardy-Littlewood-Sobolev type inequality whose sharp constant is determined as
well.Comment: 9 page
Dynamic Web File Format Transformations with Grace
Web accessible content stored in obscure, unpopular or obsolete formats
represents a significant problem for digital preservation. The file formats
that encode web content represent the implicit and explicit choices of web site
maintainers at a particular point in time. Older file formats that have fallen
out of favor are obviously a problem, but so are new file formats that have not
yet been fully supported by browsers. Often browsers use plug-in software for
displaying old and new formats, but plug-ins can be difficult to find, install
and replicate across all environments that one may use. We introduce Grace, an
http proxy server that transparently converts browser-incompatible and obsolete
web content into web content that a browser is able to display without the use
of plug-ins. Grace is configurable on a per user basis and can be expanded to
provide an array of conversion services. We illustrate how the Grace prototype
transforms several image formats (XBM, PNG with various alpha channels, and
JPEG 2000) so they are viewable in Internet Explorer.Comment: 12 pages, 9 figure
Recommended from our members
Vitis vinifera (Vitales: Vitaceae) as a Reproductive Host of Spissistilus festinus (Hemiptera: Membracidae).
Feeding by the three-cornered alfalfa hopper, Spissistilus festinus (Say) (Hemiptera: Membracidae) results in girdling of grapevine petioles and shoots. Its significance as an economic pest of grape has increased since it was shown to transmit Grapevine red blotch virus (GRBV) in a greenhouse study. However, the status of grapevines as a reproductive host for S. festinus remained undetermined. Adult S. festinus were caged onto three regions of the grapevines: apical shoot, green shoot, and dormant cane. Their ability to reproduce was determined by weekly destructive sampling for 7 wk. Successful oviposition and nymphal emergence were observed on apical and green shoots, but not on dormant canes. However, insect development beyond the second nymphal instar did not occur. Knowledge of S. festinus reproduction on grapevines will be an important consideration in designing management guidelines to minimize the spread of GRBV in vineyards
Tracking Pacific bluefin tuna (Thunnus thynnus orientalis) in the northeastern Pacific with an automated algorithm that estimates latitude by matching sea-surface-temperature data from satellites with temperature data from tags on fish
Data recovered from 11 popup satellite archival tags and 3
surgically implanted archival tags were used to analyze the movement patterns of juvenile northern bluefin tuna (Thunnus thynnus orientalis) in the eastern Pacific. The light sensors on archival and pop-up satellite transmitting
archival tags (PSATs) provide data on the time of sunrise
and sunset, allowing the calculation of an approximate geographic position of the animal. Light-based estimates
of longitude are relatively robust but latitude estimates are prone to large degrees of error, particularly near the times of the equinoxes and when the tag is at low latitudes. Estimating latitude remains a problem for
researchers using light-based geolocation algorithms and it has been suggested that sea surface temperature data from satellites may be a useful tool for refining latitude estimates. Tag data from bluefin tuna were subjected to a newly developed algorithm, called “PSAT Tracker,” which automatically matches sea surface temperature data from the tags with sea surface temperatures recorded by satellites.
The results of this algorithm compared favorably to the estimates of latitude calculated with the lightbased
algorithms and allowed for estimation of fish positions during times of the year when the lightbased algorithms failed. Three near one-year tracks produced by PSAT tracker showed that the fish range from the California−Oregon border
to southern Baja California, Mexico, and that the majority of time is spent off the coast of central Baja Mexico. A seasonal movement pattern was evident; the fish spend winter and spring off central Baja California, and summer through fall is spent moving northward to Oregon and returning to Baja California
- …