656 research outputs found
Effects of impact noise on the hearing of military personnel
Shooting is an activity that exposes military personnel to noise impact, which may cause irreversible effects on hearing. Objective: To evaluate impact noise on the hearing of military personnel that practice shooting. Study design: A case-control retrospective study. Methods: 115 military personnel were enrolled; 65 had been exposed to impact noise and 50 were non-exposed. Firearm noise levels were evaluated, subjects answered a questionnaire and underwent threshold tonal audiometry and otoacoustic emissions testing. Results: The average noise level was 125dB(C). Most subjects (78%) believe that noise may cause hearing loss; nearly all (92.3%) used ear noise protectors while shooting, but most (32.3%) had never received guidance for using this equipment. There were significant differences between the two groups in relation to changes suggesting impact noise-induced hearing loss. Conclusion: The differences between groups show that noise-exposed military personnel are more likely to develop hearing loss. The goal of a hearing conservation program for this population should be to preserve hearing and educate these individuals about the importance of using hearing protection correctly.77674775
Diffusion methods for wind power ramp detection
The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-38679-4_9Proceedings of 12th International Work-Conference on Artificial Neural Networks, IWANN 2013, Puerto de la Cruz, Tenerife, Spain, June 12-14, 2013, Part IThe prediction and management of wind power ramps is currently receiving large attention as it is a crucial issue for both system operators and wind farm managers. However, this is still an issue far from being solved and in this work we will address it as a classification problem working with delay vectors of the wind power time series and applying local Mahalanobis K-NN search with metrics derived from Anisotropic Diffusion methods. The resulting procedures clearly outperform a random baseline method and yield good sensitivity but more work is needed to improve on specificity and, hence, precision.With partial support from Spain's grant TIN2010-21575-
C02-01 and the UAM-ADIC Chair for Machine Learning. The rst author is also
supported by an FPI-UAM grant and kindly thanks the Applied Mathematics
Department of Yale University for receiving her during her visits. The second
author is supported by the FPU-MEC grant AP2008-00167
Global well-posedness of the 3-D full water wave problem
We consider the problem of global in time existence and uniqueness of
solutions of the 3-D infinite depth full water wave problem. We show that the
nature of the nonlinearity of the water wave equation is essentially of cubic
and higher orders. For any initial interface that is sufficiently small in its
steepness and velocity, we show that there exists a unique smooth solution of
the full water wave problem for all time, and the solution decays at the rate
.Comment: 60 page
A Rigorous Justification of the Modulation Approximation to the 2D Full Water Wave Problem
We consider the 2D inviscid incompressible irrotational infinite depth water
wave problem neglecting surface tension. Given wave packet initial data, we
show that the modulation of the solution is a profile traveling at group
velocity and governed by a focusing cubic nonlinear Schrodinger equation, with
rigorous error estimates in Sobolev spaces. As a consequence, we establish
existence of solutions of the water wave problem in Sobolev spaces for times in
the NLS regime provided the initial data is suitably close to a wave packet of
sufficiently small amplitude in Sobolev spaces
Hormander class of pseudo-differential operators on compact Lie groups and global hypoellipticity
In this paper we give several global characterisations of the Hormander class
of pseudo-differential operators on compact Lie groups. The result is applied
to give criteria for the ellipticity and the global hypoellipticity of
pseudo-differential operators in terms of their matrix-valued full symbols.
Several examples of the first and second order globally hypoelliptic
differential operators are given. Where the global hypoelliptiticy fails, one
can construct explicit examples based on the analysis of the global symbols.Comment: 20 page
Weighted norm inequalities for polynomial expansions associated to some measures with mass points
Fourier series in orthogonal polynomials with respect to a measure on
are studied when is a linear combination of a generalized Jacobi
weight and finitely many Dirac deltas in . We prove some weighted norm
inequalities for the partial sum operators , their maximal operator
and the commutator , where denotes the operator of pointwise
multiplication by b \in \BMO. We also prove some norm inequalities for
when is a sum of a Laguerre weight on and a positive mass on
Resolvent Estimates in L^p for the Stokes Operator in Lipschitz Domains
We establish the resolvent estimates for the Stokes operator in
Lipschitz domains in , for . The result, in particular, implies that the Stokes operator in a
three-dimensional Lipschitz domain generates a bounded analytic semigroup in
for (3/2)-\varep < p< 3+\epsilon. This gives an affirmative answer to a
conjecture of M. Taylor.Comment: 28 page. Minor revision was made regarding the definition of the
Stokes operator in Lipschitz domain
Local Interpretation Methods to Machine Learning Using the Domain of the Feature Space
As machine learning becomes an important part of many real world applications
affecting human lives, new requirements, besides high predictive accuracy,
become important. One important requirement is transparency, which has been
associated with model interpretability. Many machine learning algorithms induce
models difficult to interpret, named black box. Moreover, people have
difficulty to trust models that cannot be explained. In particular for machine
learning, many groups are investigating new methods able to explain black box
models. These methods usually look inside the black models to explain their
inner work. By doing so, they allow the interpretation of the decision making
process used by black box models. Among the recently proposed model
interpretation methods, there is a group, named local estimators, which are
designed to explain how the label of particular instance is predicted. For
such, they induce interpretable models on the neighborhood of the instance to
be explained. Local estimators have been successfully used to explain specific
predictions. Although they provide some degree of model interpretability, it is
still not clear what is the best way to implement and apply them. Open
questions include: how to best define the neighborhood of an instance? How to
control the trade-off between the accuracy of the interpretation method and its
interpretability? How to make the obtained solution robust to small variations
on the instance to be explained? To answer to these questions, we propose and
investigate two strategies: (i) using data instance properties to provide
improved explanations, and (ii) making sure that the neighborhood of an
instance is properly defined by taking the geometry of the domain of the
feature space into account. We evaluate these strategies in a regression task
and present experimental results that show that they can improve local
explanations
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Rapid fluctuations in functional connectivity of cortical networks encode spontaneous behavior
Experimental work across species has demonstrated that spontaneously generated behaviors are robustly coupled to variations in neural activity within the cerebral cortex. Functional magnetic resonance imaging data suggest that temporal correlations in cortical networks vary across distinct behavioral states, providing for the dynamic reorganization of patterned activity. However, these data generally lack the temporal resolution to establish links between cortical signals and the continuously varying fluctuations in spontaneous behavior observed in awake animals. Here, we used wide-field mesoscopic calcium imaging to monitor cortical dynamics in awake mice and developed an approach to quantify rapidly time-varying functional connectivity. We show that spontaneous behaviors are represented by fast changes in both the magnitude and correlational structure of cortical network activity. Combining mesoscopic imaging with simultaneous cellular-resolution two-photon microscopy demonstrated that correlations among neighboring neurons and between local and large-scale networks also encode behavior. Finally, the dynamic functional connectivity of mesoscale signals revealed subnetworks not predicted by traditional anatomical atlas-based parcellation of the cortex. These results provide new insights into how behavioral information is represented across the neocortex and demonstrate an analytical framework for investigating time-varying functional connectivity in neural networks
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