6,032 research outputs found
Optimized Still Image Batch Processing of Special Collections Bound Monographs and Manuscripts Using DNG, JPEG 2000, and Embedded XMP Metadata
Batch still image processing is examined in the context of operational bound monographs and manuscripts reformatting. The scaling of overall workflows through the flexible use of Lightroom, Photoshop, VueScan, and Jhove on parametrically-edited raw DNG and batch-rendered JPEG 2000 files is surveyed. Potential gains in processing efficiency, in comprehensive device data capture and preservation, in adaptable master image repurposing capabilities, and in the smoother growth of the required large-scale digital storage capacities that surround such operational conversions are considered
Saffman-Taylor fingers with kinetic undercooling
The mathematical model of a steadily propagating Saffman-Taylor finger in a
Hele-Shaw channel has applications to two-dimensional interacting streamer
discharges which are aligned in a periodic array. In the streamer context, the
relevant regularisation on the interface is not provided by surface tension,
but instead has been postulated to involve a mechanism equivalent to kinetic
undercooling, which acts to penalise high velocities and prevent blow-up of the
unregularised solution. Previous asymptotic results for the Hele-Shaw finger
problem with kinetic undercooling suggest that for a given value of the kinetic
undercooling parameter, there is a discrete set of possible finger shapes, each
analytic at the nose and occupying a different fraction of the channel width.
In the limit in which the kinetic undercooling parameter vanishes, the fraction
for each family approaches 1/2, suggesting that this 'selection' of 1/2 by
kinetic undercooling is qualitatively similar to the well-known analogue with
surface tension. We treat the numerical problem of computing these
Saffman-Taylor fingers with kinetic undercooling, which turns out to be more
subtle than the analogue with surface tension, since kinetic undercooling
permits finger shapes which are corner-free but not analytic. We provide
numerical evidence for the selection mechanism by setting up a problem with
both kinetic undercooling and surface tension, and numerically taking the limit
that the surface tension vanishes.Comment: 10 pages, 6 figures, accepted for publication by Physical Review
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