172 research outputs found
A Multiclassifier Approach for Drill Wear Prediction
Classification methods have been widely used during last years in order to predict patterns and trends of interest in data. In present paper, a multiclassifier approach that combines the output of some of the most popular data mining algorithms is shown. The approach is based on voting criteria, by estimating the confidence distributions of each algorithm individually and combining them according to three different methods: confidence voting, weighted voting and majority voting. To illustrate its applicability in a real problem, the drill wear detection in machine-tool sector is addressed. In this study, the accuracy obtained by each isolated classifier is compared with the performance of the multiclassifier when characterizing the patterns of interest involved in the drilling process and predicting the drill wear. Experimental results show that, in general, false positives obtained by the classifiers can be slightly reduced by using the multiclassifier approach
Mechanics: non-classical, non-quantum
A non-classical, non-quantum theory, or NCQ, is any fully consistent theory
that differs fundamentally from both the corresponding classical and quantum
theories, while exhibiting certain features common to both. Such theories are
of interest for two primary reasons. Firstly, NCQs arise prominently in
semi-classical approximation schemes. Their formal study may yield improved
approximation techniques in the near-classical regime. More importantly for the
purposes of this note, it may be possible for NCQs to reproduce quantum results
over experimentally tested regimes while having a well defined classical limit,
and hence are viable alternative theories. We illustrate an NCQ by considering
an explicit class of NCQ mechanics. Here this class will be arrived at via a
natural generalization of classical mechanics formulated in terms of a
probability density functional
On the Formation Height of the SDO/HMI Fe 6173 Doppler Signal
The Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics
Observatory (SDO) is designed to study oscillations and the mag- netic field in
the solar photosphere. It observes the full solar disk in the Fe I absorption
line at 6173\AA . We use the output of a high-resolution 3D, time- dependent,
radiation-hydrodynamic simulation based on the CO5BOLD code to calculate
profiles F({\lambda},x,y,t) for the Fe I 6173{\AA} line. The emerging profiles
F({\lambda},x,y,t) are multiplied by a representative set of HMI filter
transmission profiles R_i({\lambda},1 \leq i \leq 6) and filtergrams
I_i(x,y,t;1 \leq i \leq 6) are constructed for six wavelengths. Doppler
velocities V_HMI(x,y,t) are determined from these filtergrams using a
simplified version of the HMI pipeline. The Doppler velocities are correlated
with the original velocities in the simulated atmosphere. The cross-
correlation peaks near 100 km, suggesting that the HMI Doppler velocity signal
is formed rather low in the solar atmosphere. The same analysis is performed
for the SOHO/MDI Ni I line at 6768\AA . The MDI Doppler signal is formed
slightly higher at around 125 km. Taking into account the limited spatial
resolution of the instruments, the apparent formation height of both the HMI
and MDI Doppler signal increases by 40 to 50 km. We also study how
uncertainties in the HMI filter-transmission profiles affect the calculated
velocities.Comment: 15 pages, 11 Figure
Testing the Nature of Kaluza-Klein Excitations at Future Lepton Colliders
With one extra dimension, current high precision electroweak data constrain
the masses of the first Kaluza-Klein excitations of the Standard Model gauge
fields to lie above TeV. States with masses not much larger than
this should be observable at the LHC. However, even for first excitation masses
close to this lower bound, the second set of excitations will be too heavy to
be produced thus eliminating the possibility of realizing the cleanest
signature for KK scenarios. Previous studies of heavy and production
in this mass range at the LHC have demonstrated that very little information
can be obtained about their couplings to the conventional fermions given the
limited available statistics and imply that the LHC cannot distinguish an
ordinary from the degenerate pair of the first KK excitations of the
and . In this paper we discuss the capability of lepton colliders
with center of mass energies significantly below the excitation mass to resolve
this ambiguity. In addition, we examine how direct measurements obtained on and
near the top of the first excitation peak at lepton colliders can confirm these
results. For more than one extra dimension we demonstrate that it is likely
that the first KK excitation is too massive to be produced at the LHC.Comment: 38 pages, 10 Figs, LaTex, comments adde
The Dark Sides of Social Policy: From Neoliberalism to Resurgent Right-wing Populism
This Forum Debate explores the confluence of neoliberal, populist, conservative and reactionary influences on contemporary ideologies and practices of social policy, with a focus on the poorer peripheries of global
Herschel observations of EXtra-Ordinary Sources (HEXOS): Observations of H2O and its isotopologues towards Orion KL
We report the detection of more than 48 velocity-resolved ground rotational state transitions of H 16
2 O, H 18
2 O, and H 17
2 O – most for the first time
– in both emission and absorption toward Orion KL using Herschel/HIFI. We show that a simple fit, constrained to match the known emission
and absorption components along the line of sight, is in excellent agreement with the spectral profiles of all the water lines. Using the measured
H 18
2 O line fluxes, which are less affected by line opacity than their H 16
2 O counterparts, and an escape probability method, the column densities
of H 18
2 O associated with each emission component are derived. We infer total water abundances of 7.4 × 10−5, 1.0× 10−5, and 1.6 × 10−5 for the
plateau, hot core, and extended warm gas, respectively. In the case of the plateau, this value is consistent with previous measures of the Orion-KL
water abundance as well as those of other molecular outflows. In the case of the hot core and extended warm gas, these values are somewhat higher
than water abundances derived for other quiescent clouds, suggesting that these regions are likely experiencing enhanced water-ice sublimation
from (and reduced freeze-out onto) grain surfaces due to the warmer dust in these sources
Herschel observations of EXtra-Ordinary Sources (HEXOS): Detection of hydrogen fluoride in absorption towards Orion KL
We report a detection of the fundamental rotational transition of hydrogen fluoride in absorption towards Orion KL using Herschel/HIFI. After the
removal of contaminating features associated with common molecules (“weeds”), the HF spectrum shows a P-Cygni profile, with weak redshifted
emission and strong blue-shifted absorption, associated with the low-velocity molecular outflow. We derive an estimate of 2.9 × 1013 cm−2 for the
HF column density responsible for the broad absorption component. Using our best estimate of the H2 column density within the low-velocity
molecular outflow, we obtain a lower limit of ∼1.6 × 10−10 for the HF abundance relative to hydrogen nuclei, corresponding to ∼0.6% of the solar
abundance of fluorine. This value is close to that inferred from previous ISO observations of HF J = 2−1 absorption towards Sgr B2, but is in
sharp contrast to the lower limit of 6 × 10−9 derived by Neufeld et al. for cold, foreground clouds on the line of sight towards G10.6-0.4
Herschel observations of deuterated water towards Sgr B2(M)
Observations of HDO are an important complement for studies of water, because they give strong constraints on the formation processes – grain
surfaces versus energetic process in the gas phase, e.g. in shocks. The HIFI observations of multiple transitions of HDO in Sgr B2(M) presented
here allow the determination of the HDO abundance throughout the envelope, which has not been possible before with ground-based observations
only. The abundance structure has been modeled with the spherical Monte Carlo radiative transfer code RATRAN, which also takes radiative
pumping by continuum emission from dust into account. The modeling reveals that the abundance of HDO rises steeply with temperature from
a low abundance (2.5 × 10−11) in the outer envelope at temperatures below 100 K through a medium abundance (1.5 × 10−9) in the inner
envelope/outer core at temperatures between 100 and 200 K, and finally a high abundance ( 3.5 × 10−9) at temperatures above 200 K in the hot
core
Herschel observations of EXtra-Ordinary Sources (HEXOS): The present and future of spectral surveys with Herschel/HIFI
We present initial results from the Herschel GT key program: Herschel observations of EXtra-Ordinary Sources (HEXOS) and outline the promise
and potential of spectral surveys with Herschel/HIFI. The HIFI instrument offers unprecedented sensitivity, as well as continuous spectral coverage
across the gaps imposed by the atmosphere, opening up a largely unexplored wavelength regime to high-resolution spectroscopy. We show the
spectrum of Orion KL between 480 and 560 GHz and from 1.06 to 1.115 THz. From these data, we confirm that HIFI separately measures the dust
continuum and spectrally resolves emission lines in Orion KL. Based on this capability we demonstrate that the line contribution to the broad-band
continuum in this molecule-rich source is ∼20−40% below 1 THz and declines to a few percent at higher frequencies. We also tentatively identify
multiple transitions of HD18O in the spectra. The first detection of this rare isotopologue in the interstellar medium suggests that HDO emission is
optically thick in the Orion hot core with HDO/H2O ∼ 0.02. We discuss the implications of this detection for the water D/H ratio in hot cores
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