منابع مشابه
Instrumentation: astronomers look to nanotechnology.
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It is known that one can fold a convex polyhedron from a non-overlapping face unfolding, but the complexity of the algorithm in [MP] remains an open problem. In this paper we show that every convex polyhedron P ⊂ R can be obtained in polynomial time, by starting with a cube which contains P and sequentially cutting out the extra parts of the surface. Our main tool is of independent interest. We...
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We prove an identity of Segre classes for zero-schemes of compatible sections of two vector bundles. Applications include bounds on the number of equations needed to cut out a scheme with the same Segre class as a given subscheme of (for example) a projective variety, and a ‘Segre-Bertini’ theorem controlling the behavior of Segre classes of singularity subschemes of hypersurfaces under general...
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Allergic diseases encompass a group of disorders common in childhood, including eczema, asthma, and allergic rhinoconjunctivitis (ARC). Though disparate in presentation, these disorders share a common biologic origin, and over the past quarter century this group of disorders has grown from relative obscurity to near ubiquity, with a lifetime prevalence approaching 20% in school-age children in ...
متن کاملAre There Other Earths Out There? Astronomers’ First Clues to an Answer Date Back 100 Years
kids.frontiersin.org Of all the questions that science might hope to answer, few excite people more than “is there life on worlds other than our Earth, and, if so, do any alien creatures possess intelligence similar to that of human beings?” But how can we find rocky Earth-like worlds that orbit around stars other than our Sun? Remarkably, the first astronomical evidence that such worlds exist ...
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ژورنال
عنوان ژورنال: Nature
سال: 2006
ISSN: 0028-0836,1476-4679
DOI: 10.1038/439250a