13,262 research outputs found
Fifty Years of Candidate Pulsar Selection - What next?
For fifty years astronomers have been searching for pulsar signals in
observational data. Throughout this time the process of choosing detections
worthy of investigation, so called candidate selection, has been effective,
yielding thousands of pulsar discoveries. Yet in recent years technological
advances have permitted the proliferation of pulsar-like candidates, straining
our candidate selection capabilities, and ultimately reducing selection
accuracy. To overcome such problems, we now apply intelligent machine learning
tools. Whilst these have achieved success, candidate volumes continue to
increase, and our methods have to evolve to keep pace with the change. This
talk considers how to meet this challenge as a community.Comment: 4 pages, submitted: Proceedings of Pulsar Astrophysics: The Next
Fifty Years, IAU Symposium 33
Feasibility of using S-191 infrared spectra for geological studies from space
There are no author-identified significant results in this report
Analytical procedure for determining random load acting on a spacecraft due to a primary random load acting on an exterior structure Quarterly report no. 2, 1 Sep. - 30 Nov. 1965
Sound and vibration transmission in OGO SPACECRAFT shroud syste
Hellinger Distance Trees for Imbalanced Streams
Classifiers trained on data sets possessing an imbalanced class distribution
are known to exhibit poor generalisation performance. This is known as the
imbalanced learning problem. The problem becomes particularly acute when we
consider incremental classifiers operating on imbalanced data streams,
especially when the learning objective is rare class identification. As
accuracy may provide a misleading impression of performance on imbalanced data,
existing stream classifiers based on accuracy can suffer poor minority class
performance on imbalanced streams, with the result being low minority class
recall rates. In this paper we address this deficiency by proposing the use of
the Hellinger distance measure, as a very fast decision tree split criterion.
We demonstrate that by using Hellinger a statistically significant improvement
in recall rates on imbalanced data streams can be achieved, with an acceptable
increase in the false positive rate.Comment: 6 Pages, 2 figures, to be published in Proceedings 22nd International
Conference on Pattern Recognition (ICPR) 201
The prediction and measurement of sound radiated by structures
Theories regarding the radiation of sound are reviewed and the implementation in strategies for explaining or measuring the sound produced by practical strucutres are discussed. Particular attention is given to those aspects that relate to the determination of the relative amounts of sound generated by various parts of a machine or structure, which can be very useful information for noise reduction efforts
Electron Spin Resonance at the Level of 10000 Spins Using Low Impedance Superconducting Resonators
We report on electron spin resonance (ESR) measurements of phosphorus donors
localized in a 200 square micron area below the inductive wire of a lumped
element superconducting resonator. By combining quantum limited parametric
amplification with a low impedance microwave resonator design we are able to
detect around 20000 spins with a signal-to-noise ratio (SNR) of 1 in a single
shot. The 150 Hz coupling strength between the resonator field and individual
spins is significantly larger than the 1 - 10 Hz coupling rates obtained with
typical coplanar waveguide resonator designs. Due to the larger coupling rate,
we find that spin relaxation is dominated by radiative decay into the resonator
and dependent upon the spin-resonator detuning, as predicted by Purcell
Reevaluation of the normative minerals of Sonora Pass rock standards - University of Nevada reports 7 and 12
Chemical analyses and normative minerals of Nevada mountain pass rock
- …