46,252 research outputs found
Eye-CU: Sleep Pose Classification for Healthcare using Multimodal Multiview Data
Manual analysis of body poses of bed-ridden patients requires staff to
continuously track and record patient poses. Two limitations in the
dissemination of pose-related therapies are scarce human resources and
unreliable automated systems. This work addresses these issues by introducing a
new method and a new system for robust automated classification of sleep poses
in an Intensive Care Unit (ICU) environment. The new method,
coupled-constrained Least-Squares (cc-LS), uses multimodal and multiview (MM)
data and finds the set of modality trust values that minimizes the difference
between expected and estimated labels. The new system, Eye-CU, is an affordable
multi-sensor modular system for unobtrusive data collection and analysis in
healthcare. Experimental results indicate that the performance of cc-LS matches
the performance of existing methods in ideal scenarios. This method outperforms
the latest techniques in challenging scenarios by 13% for those with poor
illumination and by 70% for those with both poor illumination and occlusions.
Results also show that a reduced Eye-CU configuration can classify poses
without pressure information with only a slight drop in its performance.Comment: Ten-page manuscript including references and ten figure
The thermo-stressed state of steam turbine rotors during plant start-up
This article suggests the use of the value of the thermo-stressed state in the turbine steam input stage as one of the key parameters characterizing the start-up reliability of the turbine plant cycle. The authors present the principles of the development of the steam turbine rotor warming model for continuous monitoring of its thermo-stressed state, using a personal computer in real time. The research conducted on the thermo-stressed state of the rotor using a universal CAE programme allowed the hypothesizing of the maximum thermo-stressed states as can be calculated with sufficient precision by ‘characteristic’ temperature differences inside the rotor. It is proposed to evaluate the thermo-stressed states using regression dependence on the ‘characteristic’ differences of the real-time temperature field. Samples for the regression analysis are obtained from preliminary results of CAE programme calculations. An example is given for the whole range of the necessary computational research to produce modules of a control device for the steam turbine T-110/120-130. The modules are tested in the MATLAB Simulink environment
Mapping accretion and its variability in the young open cluster NGC 2264: a study based on u-band photometry
We aim at characterizing the accretion properties of several hundred members
of the star-forming cluster NGC 2264 (3 Myr). We performed a deep u,g,r,i
mapping and a simultaneous u+r monitoring of the region with CFHT/MegaCam in
order to directly probe the accretion process from UV excess measurements.
Photometric properties and stellar parameters are determined homogeneously for
about 750 monitored young objects, spanning the mass range 0.1-2 Mo. About 40%
are classical (accreting) T Tauri stars, based on various diagnostics (H_alpha,
UV and IR excesses). The remaining non-accreting members define the
(photospheric+chromospheric) reference UV emission level over which flux excess
is detected and measured. We revise the membership status of cluster members
based on UV accretion signatures and report a new population of 50 CTTS
candidates. A large range of UV excess is measured for the CTTS population,
varying from a few 0.1 to 3 mag. We convert these values to accretion
luminosities and obtain mass accretion rates ranging from 1e-10 to 1e-7 Mo/yr.
Taking into account a mass-dependent detection threshold for weakly accreting
objects, we find a >6sigma correlation between mass accretion rate and stellar
mass. A power-law fit, properly accounting for upper limits, yields M_acc
M^{1.4+/-0.3}. At any given stellar mass, we find a large spread of
accretion rates, extending over about 2 orders of magnitude. The monitoring of
the UV excess on a timescale of a couple of weeks indicates that its
variability typically amounts to 0.5 dex, much smaller than the observed
spread. We suggest that a non-negligible age spread across the cluster may
effectively contribute to the observed spread in accretion rates at a given
mass. In addition, different accretion mechanisms (like, e.g., short-lived
accretion bursts vs. more stable funnel-flow accretion) may be associated to
different M_acc regimes.Comment: 24 pages, 21 figures, accepted for publication in Astronomy &
Astrophysic
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