613 research outputs found
Odd-harmonic repetitive control of an active filter under varying network frequency: control design and stability analysis
This work deals with the design and analysis of a
controller for a shunt active power filter. The design is based
on combined feedforward and feedback actions, the last using
repetitive control, and aims at the obtention of a good closedloop
performance in spite of the possible frequency variations
that may occur in the electrical network. As these changes
affect the performance of the controller, the proposal includes
a compensation technique consisting of an adaptive change of
the digital controller’s sampling time according to the network
frequency variation. However, this implies structural changes in
the closed-loop system that may destabilize the overall system.
Hence, this article is also concerned with closed-loop stability of
the resulting system, which is analyzed using a robust control
approach through the small gain theorem. Experimental results
that indicate good performance of the closed-loop system are
provided.Postprint (published version
Setting the cornerstone for the IMRPhenomX family of models for gravitational waves from compact binaries: The dominant harmonic for non-precessing quasi-circular black holes
In this paper we present IMRPhenomXAS, a thorough overhaul of the IMRPhenomD
[1,2] waveform model, which describes the dominant spherical
harmonic mode of non-precessing coalescing black holes in terms of piecewise
closed form expressions in the frequency domain. Improvements include in
particular the accurate treatment of unequal spin effects, and the inclusion of
extreme mass ratio waveforms. IMRPhenomD has previously been extended to
approximately include spin precession [3] and subdominant spherical harmonics
[4], and with its extensions it has become a standard tool in gravitational
wave parameter estimation. Improved extensions of IMRPhenomXAS are discussed in
companion papers [5,6].Comment: 29 pages. 20 figures. Comments and feedback welcome! This paper
corresponds to LIGO DCC P200001
IMRPhenomXHM: A multi-mode frequency-domain model for the gravitational wave signal from non-precessing black-hole binaries
We present the IMRPhenomXHM frequency domain phenomenological waveform model
for the inspiral, merger and ringdown of quasi-circular non-precessing black
hole binaries. The model extends the IMRPhenomXAS waveform model, which
describes the dominant quadrupole modes , to the harmonics
, and includes mode mixing effects for
the spherical harmonic. IMRPhenomXHM is calibrated against hybrid
waveforms, which match an inspiral phase described by the effective-one-body
model and post-Newtonian amplitudes for the subdominant harmonics to numerical
relativity waveforms and numerical solutions to the perturbative Teukolsky
equation for large mass ratios up to 1000.
A computationally efficient implementation of the model is available as part
of the LSC Algorithm Library Suite.Comment: 30 pages, 23 figures. Updated to match published versio
Associació entre la malaltia renal crònica i la malaltia cardiovascular a la població general mediterrània
Construction and validation of a scoring system for the selection of high-quality data in a Spanish population primary care database (SIDIAP).
BACKGROUND: Computerised databases of primary care clinical records are widely used for epidemiological research. In Catalonia, the Information System for the Development of Research in Primary Care (SIDIAP) aims to promote the development of research based on high-quality validated data from primary care electronic medical records. OBJECTIVE: The purpose of this study is to create and validate a scoring system (Registry Quality Score, RQS) that will enable all primary care practices (PCPs) to be selected as providers of researchusable data based on the completeness of their registers. METHODS: Diseases that were likely to be representative of common diagnoses seen in primary care were selected for RQS calculations. The observed/expected cases ratio was calculated for each disease. Once we had obtained an estimated value for this ratio for each of the selected conditions we added up the ratios calculated for each condition to obtain a final RQS. Rate comparisons between observed and published prevalences of diseases not included in the RQS calculations (atrial fibrillation, diabetes, obesity, schizophrenia, stroke, urinary incontinence and Crohn's disease) were used to set the RQS cutoff which will enable researchers to select PCPs with research-usable data. RESULTS: Apart from Crohn's disease, all prevalences were the same as those published from the RQS fourth quintile (60th percentile) onwards. This RQS cut-off provided a total population of 1 936 443 (39.6% of the total SIDIAP population). CONCLUSIONS: SIDIAP is highly representative of the population of Catalonia in terms of geographical, age and sex distributions. We report the usefulness of rate comparison as a valid method to establish research-usable data within primary care electronic medical records
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