282 research outputs found
Retrospective-Cost-Based Adaptive Input and State Estimation for the Ionosphere–Thermosphere
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140666/1/1.I010286.pd
Retrospective Cost Optimization for Adaptive State Estimation, Input Estimation, and Model Refinement
AbstractRetrospective cost optimization was originally developed for adaptive control. In this paper, we show how this technique is applicable to three distinct but related problems, namely, state estimation, input estimation, and model refinement. To illustrate these techniques, we give two examples. In the first example, retrospective cost model refinement is used with synthetic data to estimate the cooling dynamics that are missing from a model of the ionosphere-thermosphere. In the second example, retrospective cost adaptive state estimation is used with data from a satellite to estimate a solar driver in the ionosphere- thermosphere, with performance gauged by using data from a second satellite
Structural and molecular interrogation of intact biological systems
Obtaining high-resolution information from a complex system, while maintaining the global perspective needed to understand system function, represents a key challenge in biology. Here we address this challenge with a method (termed CLARITY) for the transformation of intact tissue into a nanoporous hydrogel-hybridized form (crosslinked to a three-dimensional network of hydrophilic polymers) that is fully assembled but optically transparent and macromolecule-permeable. Using mouse brains, we show intact-tissue imaging of long-range projections, local circuit wiring, cellular relationships, subcellular structures, protein complexes, nucleic acids and neurotransmitters. CLARITY also enables intact-tissue in situ hybridization, immunohistochemistry with multiple rounds of staining and de-staining in non-sectioned tissue, and antibody labelling throughout the intact adult mouse brain. Finally, we show that CLARITY enables fine structural analysis of clinical samples, including non-sectioned human tissue from a neuropsychiatric-disease setting, establishing a path for the transmutation of human tissue into a stable, intact and accessible form suitable for probing structural and molecular underpinnings of physiological function and disease
Global model comparison with Millstone Hill during September 2005
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95551/1/jgra18878.pd
The Impact of Inpatient Boarding on ED Efficiency: A Discrete-Event Simulation Study
In this study, a discrete-event simulation approach was used to model Emergency Department’s (ED) patient flow to investigate the effect of inpatient boarding on the ED efficiency in terms of the National Emergency Department Crowding Scale (NEDOCS) score and the rate of patients who leave without being seen (LWBS). The decision variable in this model was the boarder-released-ratio defined as the ratio of admitted patients whose boarding time is zero to all admitted patients. Our analysis shows that the Overcrowded+ (a NEDOCS score over 100) ratio decreased from 88.4% to 50.4%, and the rate of LWBS patients decreased from 10.8% to 8.4% when the boarder-released-ratio changed from 0% to 100%. These results show that inpatient boarding significantly impacts both the NEDOCS score and the rate of LWBS patient and this analysis provides a quantification of the impact of boarding on emergency department patient crowding
The impact of camera optical alignments on weak lensing measures for the Dark Energy Survey
Telescope Point Spread Function (PSF) quality is critical for realising the
potential of cosmic weak lensing observations to constrain dark energy and test
General Relativity. In this paper we use quantitative weak gravitational
lensing measures to inform the precision of lens optical alignment, with
specific reference to the Dark Energy Survey (DES). We compute optics spot
diagrams and calculate the shear and flexion of the PSF as a function of
position on the focal plane. For perfect optical alignment we verify the high
quality of the DES optical design, finding a maximum PSF contribution to the
weak lensing shear of 0.04 near the edge of the focal plane. However this can
be increased by a factor of approximately three if the lenses are only just
aligned within their maximum specified tolerances. We calculate the E and
B-mode shear and flexion variance as a function of de-centre or tilt of each
lens in turn. We find tilt accuracy to be a few times more important than
de-centre, depending on the lens considered. Finally we consider the compound
effect of de-centre and tilt of multiple lenses simultaneously, by sampling
from a plausible range of values of each parameter. We find that the compound
effect can be around twice as detrimental as when considering any one lens
alone. Furthermore, this combined effect changes the conclusions about which
lens is most important to align accurately. For DES, the tilt of the first two
lenses is the most important.Comment: 10 pages, 8 figure
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