40,209 research outputs found

    A visual analysis of the usage efficiency of library books

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    The monographic collections in academic libraries have undergone a period of tremendous growth in volume, in subject diversity, and in formats during the recent several decades. Readers may find it difficult to prioritize which book(s) should be borrowed for a specific purpose. The log data of book loan record may serve as a visible indicator for the more sought-after books by the readers. This paper describes our experimental efforts in works in a university library setting. The visual analysis is thought to provide an effective way to extract the book usage information, which may yield new insights into a host of other related technical as well as user behavior issues. Initial experiment has demonstrated that the proposed approach as articulated in this article can actually benefit end-users as well as library collection development personnel in their endeavor of book selections with effective measure.</p

    Some remarks on circle action on manifolds

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    This paper contains several results concerning circle action on almost-complex and smooth manifolds. More precisely, we show that, for an almost-complex manifold M2mnM^{2mn}(resp. a smooth manifold N4mnN^{4mn}), if there exists a partition λ=(λ1,...,λu)\lambda=(\lambda_{1},...,\lambda_{u}) of weight mm such that the Chern number (cλ1...cλu)n[M](c_{\lambda_{1}}... c_{\lambda_{u}})^{n}[M] (resp. Pontrjagin number (pλ1...pλu)n[N](p_{\lambda_{1}}... p_{\lambda_{u}})^{n}[N]) is nonzero, then \emph{any} circle action on M2mnM^{2mn} (resp. N4mnN^{4mn}) has at least n+1n+1 fixed points. When an even-dimensional smooth manifold N2nN^{2n} admits a semi-free action with isolated fixed points, we show that N2nN^{2n} bounds, which generalizes a well-known fact in the free case. We also provide a topological obstruction, in terms of the first Chern class, to the existence of semi-free circle action with \emph{nonempty} isolated fixed points on almost-complex manifolds. The main ingredients of our proofs are Bott's residue formula and rigidity theorem.Comment: 10 pages,to appear in Mathematical Research Letter

    Circle action and some vanishing results on manifolds

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    Kawakubo and Uchida showed that, if a closed oriented 4k4k-dimensional manifold MM admits a semi-free circle action such that the dimension of the fixed point set is less than 2k2k, then the signature of MM vanishes. In this note, by using GG-signature theorem and the rigidity of the signature operator, we generalize this result to more general circle actions. Combining the same idea with the remarkable Witten-Taubes-Bott rigidity theorem, we explore more vanishing results on spin manifolds admitting such circle actions. Our results are closely related to some earlier results of Conner-Floyd, Landweber-Stong and Hirzebruch-Slodowy.Comment: 7 pages, typos corrected and minors modifie

    On an algebraic formula and applications to group action on manifolds

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    We consider a purely algebraic result. Then given a circle or cyclic group of prime order action on a manifold, we will use it to estimate the lower bound of the number of fixed points. We also give an obstruction to the existence of Zp\mathbb{Z}_p action on manifolds with isolated fixed points when pp is a prime.Comment: 7 pages, revised slightly to update a new reference and reassign the credit of the idea in this not
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