1,821 research outputs found
Galaxy Modeling with Compound Elliptical Shapelets
Gauss-Hermite and Gauss-Laguerre ("shapelet") decompositions of images have
become important tools in galaxy modeling, particularly for the purpose of
extracting ellipticity and morphological information from astronomical data.
However, the standard shapelet basis functions cannot compactly represent
galaxies with high ellipticity or large Sersic index, and the resulting
underfitting bias has been shown to present a serious challenge for
weak-lensing methods based on shapelets. We present here a new convolution
relation and a compound "multi-scale" shapelet basis to address these problems,
and provide a proof-of-concept demonstration using a small sample of nearby
galaxies.Comment: 14 pages, 7 figure
Reducing Crop Nutrient Applications: The Yield Reserve Program
A proposed Yield Reserve Program designed to compensate farmers for any reduced yields resulting from reduced nitrogen (N) application rates below recommended rates is evaluated. Assuming that farmers currently follow extension recommendations for applying N, Yield Reserve Program participation reduces expected net revenue by 13/ha. The Yield Reserve Program reduces expected net revenue by 20/ha for farmers who apply N to maximize expected net revenue. Farmers costs of participation increase with lower probabilities of inadequate rainfall and higher corn prices and decline with higher N prices. The Yield Reserve Program can significantly reduce N applications to cropland, which may reduce N content of surface waters, but the costs to taxpayers and farmers will depend on how the program is implemented.compliance cost, nitrogen fertilizer, nonpoint source pollution, policy, yield response function, Crop Production/Industries,
Addicted to Mediocrity: Twentieth Century Christians and the Arts (Book Review)
Reviewed Title: Addicted to Mediocrity: Twentieth Century Christians and the Arts by Frank Schaeffer. Westchester, Illinois: Cornerstone Books, 1981. 127 pp
Spiritual Nature of Man (Book Review)
Reviewed Title: The Spiritual Nature of Man, by Alister Hardy. Oxford: Clarendon Press, 1979. 162 pp
Lionel Trilling: Criticism and Politics (Book Review)
Reviewed Title: Lionel Trilling: Criticism and Politics, by William M. Chace. Stanford, California: Stanford University Press, 1980. 200 pages
Gypsies (Book Review)
Reviewed Title: Gypsies, by Cynthia Nibbelink. University Center, Michigan: Green River Press, 1978. 141 pp
Faith and Fiction: The Modern Short Story (Book Review)
Reviewed Title: Faith and Fiction: The Modern Short Story, by Robert Detweiler and Glenn Meeter. Grand Rapids, Michigan: Wm. B. Eerdmans, 1979. 314 pages
Rainbows for the Fallen World and Art in Action (Book Reviews)
Reviewed Titles: Rainbows for the Fallen World, by Calvin Seerveld. Downsville, Ontario: Toronto Tuppence Press, 1980. 254 pp. Art in Action, by Nicholas Wolterstorff. Grand Rapids, Michigan: William B. Eerdmans Publishing Company, 1980. 240 pp
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