40 research outputs found
Equipment health monitoring with non-parametric statistics for online early detection and scoring of degradation
This paper develops a health monitoring scheme to detect and trend degradation in dynamic systems that are characterised by multiple parameter time-series data. The presented scheme provides early detection of degradation and ability to score its significance in order to inform maintenance planning and consequently reduce disruption. Non-parametric statistics are proposed to provide this early detection and scoring. The non-parametric statistics approximate the data distribution for a sliding time window, with the change in distribution is indicated using the two-sample Kolmogorov-Smirnov test. Trending the changes to the signal distribution is shown to provide diagnostic capabilities, with deviations indicating the precursors to failure. The paper applies the equipment health monitoring scheme to address the growing concerns for future gas turbine fuel metering valve availability. The fuel metering unit within a gas turbine is a complex electro-mechanical system, failures of which can be a major source of airline disruption. The application is performed on data acquired from a series of industrial tests performed on large civil aero-engine fuel metering units subjected to varying levels of contaminant. The data exhibits characteristics of degradation, which are identified and trended by the equipment health monitoring scheme presented in this paper
The spectrum of high-energy cosmic rays measured with KASCADE-Grande
The energy spectrum of cosmic rays between 10**16 eV and 10**18 eV, derived
from measurements of the shower size (total number of charged particles) and
the total muon number of extensive air showers by the KASCADE-Grande
experiment, is described. The resulting all-particle energy spectrum exhibits
strong hints for a hardening of the spectrum at approximately 2x10**16 eV and a
significant steepening at c. 8x10**16 eV. These observations challenge the view
that the spectrum is a single power law between knee and ankle. Possible
scenarios generating such features are discussed in terms of astrophysical
processes that may explain the transition region from galactic to extragalactic
origin of cosmic rays.Comment: accepted by Astroparticle Physics June 201
All-particle cosmic ray energy spectrum measured with 26 IceTop stations
We report on a measurement of the cosmic ray energy spectrum with the IceTop
air shower array, the surface component of the IceCube Neutrino Observatory at
the South Pole. The data used in this analysis were taken between June and
October, 2007, with 26 surface stations operational at that time, corresponding
to about one third of the final array. The fiducial area used in this analysis
was 0.122 km^2. The analysis investigated the energy spectrum from 1 to 100 PeV
measured for three different zenith angle ranges between 0{\deg} and 46{\deg}.
Because of the isotropy of cosmic rays in this energy range the spectra from
all zenith angle intervals have to agree. The cosmic-ray energy spectrum was
determined under different assumptions on the primary mass composition. Good
agreement of spectra in the three zenith angle ranges was found for the
assumption of pure proton and a simple two-component model. For zenith angles
{\theta} < 30{\deg}, where the mass dependence is smallest, the knee in the
cosmic ray energy spectrum was observed between 3.5 and 4.32 PeV, depending on
composition assumption. Spectral indices above the knee range from -3.08 to
-3.11 depending on primary mass composition assumption. Moreover, an indication
of a flattening of the spectrum above 22 PeV were observed.Comment: 38 pages, 17 figure
Discovery of widespread transcription initiation at microsatellites predictable by sequence-based deep neural network
Using the Cap Analysis of Gene Expression (CAGE) technology, the FANTOM5 consortium provided one of the most comprehensive maps of transcription start sites (TSSs) in several species. Strikingly, ~72% of them could not be assigned to a specific gene and initiate at unconventional regions, outside promoters or enhancers. Here, we probe these unassigned TSSs and show that, in all species studied, a significant fraction of CAGE peaks initiate at microsatellites, also called short tandem repeats (STRs). To confirm this transcription, we develop Cap Trap RNA-seq, a technology which combines cap trapping and long read MinION sequencing. We train sequence-based deep learning models able to predict CAGE signal at STRs with high accuracy. These models unveil the importance of STR surrounding sequences not only to distinguish STR classes, but also to predict the level of transcription initiation. Importantly, genetic variants linked to human diseases are preferentially found at STRs with high transcription initiation level, supporting the biological and clinical relevance of transcription initiation at STRs. Together, our results extend the repertoire of non-coding transcription associated with DNA tandem repeats and complexify STR polymorphism
Effect of nutritional pen construction on the thermal performance of broilers
SUMMARY: Nutritional test pens are commonly used to segregate and geolocate birds in commercial-scale broiler houses to control spatial variation from the environment. Pens should subject test birds to similar environmental conditions as birds roaming free in the house, however, discussions on pen construction materials, design, and placement have focused on durability and handling with little regard for the pen's thermal environment. Simulated birds were constructed with a metal bowl and a light bulb heat source to mimic the heat generation of large commercial broilers. Bowl surface temperature (BST) was measured as a model for the surface temperature of a broiler housed in a nutritional pen. Effects of panel open area (100% (control), 89%, 85%, 70%, 50%, and 30%) and air velocity (2, 3, and 4 m/s) were factorially tested on BST in a wind tunnel. Panels with an open area of less than 70% were different (P < 0.0001) from free air (100% open area). There was a difference of 5°C (9°F) for BST between the most restrictive panel (30%) and free air (100%), demonstrating a large difference in the thermal environment that birds might experience if air is restricted. Air velocity treatments were different (P < 0.0001) with mean BST increasing as air velocity decreased. Panels should be constructed with open areas greater than 70% accounting for structural framing and other obstructions as well as expected dust accumulation. While pen durability and handling are important for on-site success, these parameters should not overshadow restrictive airflow pen designs that would potentially alter thermal environmental conditions in nutritional treatment comparisons.Mention of trade names or commercial products in this article is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the authors or the U.S. Department of Agriculture