83,023 research outputs found

    The Open Navigation Surface Project

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    Many hydrographic and oceanographic agencies have moved or are moving towards gridded bathymetric products. However, there is no accepted format to allow these grids to be exchanged while maintaining data and metadata integrity. This paper describes the Open Navigation Surface (ONS) Project, which aims to fill this gap. The ONS Project is an open-source software project designed to provide a freely available, portable source-code library to encapsulate gridded bathymetric surfaces with associated uncertainty values. The data file format is called a Bathymetric Attributed Grid (BAG). The BAG is developed and maintained by the ONS Working Group (ONSWG), and the source code is available via the ONS websit

    Notion of a virtual derivative

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    Diagrams as a graphic expresion of derivatives is proposed for calculation of derivatives for composed function. The concret diagram is understood as a virtual derivative in contrast of concret derivative. In polynomial expression of functions derivative the concret derivative will be every monomic member, and the virtual derivative represent the sum of similar monomic members. The word virtual denotes that we dont need to know every virtual derivative, we don't write all the sequence of these virtual derivatives, and simply pick the needed one. This is in contrast of tradition to write the whole algebraic expresion as a denotion of whole function's derivative. Such graphic expresion can be helpful in the problems of differential geometry, in the various asymptotic expantions, also in the solution of some differential equations.Comment: The diagrams are drown with the help of xy-pic and can be automaticly generated for the derivative of large degry of more general composed functio

    Laws of large numbers in stochastic geometry with statistical applications

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    Given nn independent random marked dd-vectors (points) XiX_i distributed with a common density, define the measure νn=∑iξi\nu_n=\sum_i\xi_i, where ξi\xi_i is a measure (not necessarily a point measure) which stabilizes; this means that ξi\xi_i is determined by the (suitably rescaled) set of points near XiX_i. For bounded test functions ff on RdR^d, we give weak and strong laws of large numbers for νn(f)\nu_n(f). The general results are applied to demonstrate that an unknown set AA in dd-space can be consistently estimated, given data on which of the points XiX_i lie in AA, by the corresponding union of Voronoi cells, answering a question raised by Khmaladze and Toronjadze. Further applications are given concerning the Gamma statistic for estimating the variance in nonparametric regression.Comment: Published in at http://dx.doi.org/10.3150/07-BEJ5167 the Bernoulli (http://isi.cbs.nl/bernoulli/) by the International Statistical Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm
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