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Existing data structures which facilitate storage and retrieval of geographical data are R-trees, R* trees, KD trees etc. Most widely used and accepted structure among these is the R-tree. A drawback with R-trees is that it represents regions as fictitious rectangles which do not correspond to actual geographical regions. Also R-trees do not represent the hierarchy very well. For example New York...
We give efficient algorithms for volume sampling, i.e., for picking k-subsets of the rows of any given matrix with probabilities proportional to the squared volumes of the simplices defined by them and the origin (or the squared volumes of the parallelepipeds defined by these subsets of rows). This solves an open problem from the monograph on spectral algorithms by Kannan and Vempala (see Section...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.