4,007 research outputs found
Acoustic event detection for multiple overlapping similar sources
Many current paradigms for acoustic event detection (AED) are not adapted to
the organic variability of natural sounds, and/or they assume a limit on the
number of simultaneous sources: often only one source, or one source of each
type, may be active. These aspects are highly undesirable for applications such
as bird population monitoring. We introduce a simple method modelling the
onsets, durations and offsets of acoustic events to avoid intrinsic limits on
polyphony or on inter-event temporal patterns. We evaluate the method in a case
study with over 3000 zebra finch calls. In comparison against a HMM-based
method we find it more accurate at recovering acoustic events, and more robust
for estimating calling rates.Comment: Accepted for WASPAA 201
Standardization and Control for Confounding in Observational Studies: A Historical Perspective
Control for confounders in observational studies was generally handled
through stratification and standardization until the 1960s. Standardization
typically reweights the stratum-specific rates so that exposure categories
become comparable. With the development first of loglinear models, soon also of
nonlinear regression techniques (logistic regression, failure time regression)
that the emerging computers could handle, regression modelling became the
preferred approach, just as was already the case with multiple regression
analysis for continuous outcomes. Since the mid 1990s it has become
increasingly obvious that weighting methods are still often useful, sometimes
even necessary. On this background we aim at describing the emergence of the
modelling approach and the refinement of the weighting approach for confounder
control.Comment: Published in at http://dx.doi.org/10.1214/13-STS453 the Statistical
Science (http://www.imstat.org/sts/) by the Institute of Mathematical
Statistics (http://www.imstat.org
Legendrian contact homology and nondestabilizability
We provide the first example of a Legendrian knot with nonvanishing contact
homology whose Thurston-Bennequin invariant is not maximal.Comment: 12 pages, 2 figure
Higher-dimensional linking integrals
We derive an integral formula for the linking number of two submanifolds of
the n-sphere S^n, of the product S^n x R^m, and of other manifolds which appear
as "nice" hypersurfaces in Euclidean space. The formulas are geometrically
meaningful in that they are invariant under the action of the special
orthogonal group on the ambient space.Comment: 10 pages, 3 figure
THE ECONOMICS OF COMMUNITY GROWTH: AN IMPACT MODEL
Community/Rural/Urban Development,
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