152 research outputs found
Two-dimensional projections of an hypercube
We present a method to project a hypercube of arbitrary dimension on the
plane, in such a way as to preserve, as well as possible, the distribution of
distances between vertices. The method relies on a Montecarlo optimization
procedure that minimizes the squared difference between distances in the plane
and in the hypercube, appropriately weighted. The plane projections provide a
convenient way of visualization for dynamical processes taking place on the
hypercube.Comment: 4 pages, 3 figures, Revtex
Kernel density classification and boosting: an L2 sub analysis
Kernel density estimation is a commonly used approach to classification. However, most of the theoretical results for kernel methods apply to estimation per se and not necessarily to classification. In this paper we show that when estimating the difference between two densities, the optimal smoothing parameters are increasing functions of the sample size of the complementary group, and we provide a small simluation study which examines the relative performance of kernel density methods when the final goal is classification. A relative newcomer to the classification portfolio is “boosting”, and this paper proposes an algorithm for boosting kernel density classifiers. We note that boosting is closely linked to a previously proposed method of bias reduction in kernel density estimation and indicate how it will enjoy similar properties for classification. We show that boosting kernel classifiers reduces the bias whilst only slightly increasing the variance, with an overall reduction in error. Numerical examples and simulations are used to illustrate the findings, and we also suggest further areas of research
Metode survei dalam kedokteran komunitas / pengantar studi epidemiologi dan evaluatif
Indeks *** *** Bibliografi hlm. Setiap babviii, 344 hlm. ;21 cm
Metode survei dalam kedokteran komunitas: Pengantar studi epidemiologi dan evaluatif
viii, 344 hal; 21 c
Metode surve dalam kedokteran komunitas : pengantar studi epidemiologi dan evaluatif
Judul asli; Survey methode in community medicene an introduction to epidemological and evaluative studies344 p.; 21 cm
Metode survei dalam kedokteran komunitas: pengantar studi epidemiologi dan evaluatif/ Abramson
ix, 344 hal.; .... cm
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