222 research outputs found
Polyploidism in Deep Neural Networks: m-Parent Evolutionary Synthesis of Deep Neural Networks in Varying Population Sizes
Evolutionary deep intelligence was recently proposed to organicallyproduce highly efficient deep neural network architecturesover successive generations. Thus far, current evolutionary synthesisprocesses are based on asexual reproduction, i.e., offspringneural networks are synthesized stochastically from a single parentnetwork. In this study, we investigate the effects of m-parentsexual evolutionary synthesis (m = 1, 2, 3, 5) in combination withvarying population sizes of three, five, and eight synthesized networksper generation. Experimental results were obtained usinga 10% subset of the MNIST handwritten digits dataset, and showthat increasing the number of parent networks results in improvedarchitectural efficiency of the synthesized networks (approximately150x synaptic efficiency and approximately 42–49x cluster efficiency)while resulting in only a 2–3% drop in testing accuracy
Deep ROC Analysis and AUC as Balanced Average Accuracy to Improve Model Selection, Understanding and Interpretation
Optimal performance is critical for decision-making tasks from medicine to
autonomous driving, however common performance measures may be too general or
too specific. For binary classifiers, diagnostic tests or prognosis at a
timepoint, measures such as the area under the receiver operating
characteristic curve, or the area under the precision recall curve, are too
general because they include unrealistic decision thresholds. On the other
hand, measures such as accuracy, sensitivity or the F1 score are measures at a
single threshold that reflect an individual single probability or predicted
risk, rather than a range of individuals or risk. We propose a method in
between, deep ROC analysis, that examines groups of probabilities or predicted
risks for more insightful analysis. We translate esoteric measures into
familiar terms: AUC and the normalized concordant partial AUC are balanced
average accuracy (a new finding); the normalized partial AUC is average
sensitivity; and the normalized horizontal partial AUC is average specificity.
Along with post-test measures, we provide a method that can improve model
selection in some cases and provide interpretation and assurance for patients
in each risk group. We demonstrate deep ROC analysis in two case studies and
provide a toolkit in Python.Comment: 14 pages, 6 Figures, submitted to IEEE Transactions on Pattern
Analysis and Machine Intelligence (TPAMI), currently under revie
Precision Measurement of the Weak Mixing Angle in Moller Scattering
We report on a precision measurement of the parity-violating asymmetry in
fixed target electron-electron (Moller) scattering: A_PV = -131 +/- 14 (stat.)
+/- 10 (syst.) parts per billion, leading to the determination of the weak
mixing angle \sin^2\theta_W^eff = 0.2397 +/- 0.0010 (stat.) +/- 0.0008 (syst.),
evaluated at Q^2 = 0.026 GeV^2. Combining this result with the measurements of
\sin^2\theta_W^eff at the Z^0 pole, the running of the weak mixing angle is
observed with over 6 sigma significance. The measurement sets constraints on
new physics effects at the TeV scale.Comment: 4 pages, 2 postscript figues, submitted to Physical Review Letter
Observation of Parity Nonconservation in Moller Scattering
We report a measurement of the parity-violating asymmetry in fixed target
electron-electron (Moller) scattering: A_PV = -175 +/- 30 (stat.) +/- 20
(syst.) parts per billion. This first direct observation of parity
nonconservation in Moller scattering leads to a measurement of the electron's
weak charge at low energy Q^e_W = -0.053 +/- 0.011. This is consistent with the
Standard Model expectation at the current level of precision:
sin^2\theta_W(M_Z)_MSbar = 0.2293 +/- 0.0024 (stat.) +/- 0.0016 (syst.) +/-
0.0006 (theory).Comment: Version 3 is the same as version 2. These versions contain minor text
changes from referee comments and a change in the extracted value of Q^e_W
and sin^2\theta_W due to a change in the theoretical calculation of the
bremsstrahulung correction (ref. 16
Homotopic non-local regularized reconstruction from sparse positron emission tomography measurements
Lowering the radioactivity of the photomultiplier tubes for the XENON1T dark matter experiment
The low-background, VUV-sensitive 3-inch diameter photomultiplier tube R11410
has been developed by Hamamatsu for dark matter direct detection experiments
using liquid xenon as the target material. We present the results from the
joint effort between the XENON collaboration and the Hamamatsu company to
produce a highly radio-pure photosensor (version R11410-21) for the XENON1T
dark matter experiment. After introducing the photosensor and its components,
we show the methods and results of the radioactive contamination measurements
of the individual materials employed in the photomultiplier production. We then
discuss the adopted strategies to reduce the radioactivity of the various PMT
versions. Finally, we detail the results from screening 216 tubes with
ultra-low background germanium detectors, as well as their implications for the
expected electronic and nuclear recoil background of the XENON1T experiment.Comment: 10 pages, 5 figure
Removing krypton from xenon by cryogenic distillation to the ppq level
The XENON1T experiment aims for the direct detection of dark matter in a
cryostat filled with 3.3 tons of liquid xenon. In order to achieve the desired
sensitivity, the background induced by radioactive decays inside the detector
has to be sufficiently low. One major contributor is the -emitter
Kr which is an intrinsic contamination of the xenon. For the XENON1T
experiment a concentration of natural krypton in xenon Kr/Xe < 200
ppq (parts per quadrillion, 1 ppq = 10 mol/mol) is required. In this
work, the design of a novel cryogenic distillation column using the common
McCabe-Thiele approach is described. The system demonstrated a krypton
reduction factor of 6.410 with thermodynamic stability at process
speeds above 3 kg/h. The resulting concentration of Kr/Xe < 26 ppq
is the lowest ever achieved, almost one order of magnitude below the
requirements for XENON1T and even sufficient for future dark matter experiments
using liquid xenon, such as XENONnT and DARWIN
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