19 research outputs found
Recurrence Quantification Analysis and Principal Components in the Detection of Short Complex Signals
Recurrence plots were introduced to help aid the detection of signals in
complicated data series. This effort was furthered by the quantification of
recurrence plot elements. We now demonstrate the utility of combining
recurrence quantification analysis with principal components analysis to allow
for a probabilistic evaluation for the presence of deterministic signals in
relatively short data lengths.Comment: 10 pages, 3 figures; Elsevier preprint, elsart style; programs used
for analysis available for download at http://homepages.luc.edu/~cwebbe
Application of nonlinear time series analysis techniques to high-frequency currency exchange data
SKYSURF: Constraints on Zodiacal Light and Extragalactic Background Light through Panchromatic HST All-Sky Surface-Brightness Measurements: I. Survey Overview and Methods
We give an overview and describe the rationale, methods, and testing of the
Hubble Space Telescope (HST) Archival Legacy project "SKYSURF." SKYSURF uses
HST's unique capability as an absolute photometer to measure the ~0.2-1.7
m sky surface brightness (SB) from 249,861 WFPC2, ACS, and WFC3 exposures
in ~1400 independent HST fields. SKYSURF's panchromatic dataset is designed to
constrain the discrete and diffuse UV to near-IR sky components: Zodiacal Light
(ZL; inner Solar System), Kuiper Belt Objects (KBOs; outer Solar System),
Diffuse Galactic Light (DGL), and the discrete plus diffuse Extragalactic
Background Light (EBL). We outline SKYSURF's methods to: (1) measure sky-SB
levels between its detected objects; (2) measure the integrated discrete EBL,
most of which comes from AB17-22 mag galaxies; and (3) estimate how
much diffuse light may exist in addition to the extrapolated discrete galaxy
counts. Simulations of HST WFC3/IR images with known sky-values and gradients,
realistic cosmic ray (CR) distributions, and star plus galaxy counts were
processed with nine different algorithms to measure the "Lowest Estimated
Sky-SB" (LES) in each image between the discrete objects. The best algorithms
recover the inserted LES values within 0.2% when there are no image gradients,
and within 0.2-0.4% when there are 5-10% gradients. SKYSURF requires
non-standard re-processing of these HST images that includes restoring the
lowest sky-level from each visit into each drizzled image. We provide a proof
of concept of our methods from the WFC3/IR F125W images, where any residual
diffuse light that HST sees in excess of the Kelsall et al. (1998) Zodiacal
model prediction does not depend on the total object flux that each image
contains. This enables us to present our first SKYSURF results on diffuse light
in Carleton et al. (2022).Comment: Accepted to AJ; see accompanying paper Carleton et al. 2022:
arXiv:2205.06347. Comments welcome
The Sunflower Project: Using Sunflowers To Provide Clean Water To Those Living In Areas Polluted By Uranium Mining Via Partnership With High-School Aged Students
Mining on Naabeehó Bináhásdzo (Navajo Nation) increased ground water concentrations of uranium, arsenic, and other heavy metals. The Navajo Nation and residents of this region use groundwater for human consumption and agriculture. Currently many must transport resuited water from distant areas that are often miles away. We propose to test if uranium and other pollutants could be removed by strategic cultivation of sunflowers and similar plant species. Recent observations suggest that sunflowers, mosses, and other plants preferentially take up heavy metals, including uranium and arsenic, allowing on-site, low-cost phytoremediation of water pollution. Through partnership with local leaders and students, new relevant filtration rates, and possible plant filtration solutions will be established
A brief note on possible detection of physiological singularities in respiratory dynamics by recurrence quantification analysis of lung sounds
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Acute Hospital Outcomes for Renal Transplantation in Patients With Moderate or Severe Congenital Heart Disease
Children and adults with congenital heart disease (CHD) are increasingly recognized to be at risk for acute and chronic renal injury. Some of these may progress to the need for renal transplantation. We hypothesized that patients with underlying moderate or severe CHD who undergo renal transplantation will have worse acute hospital outcomes. Using a national administrative database, we queried for admissions aged 0 to 50 years with moderate or severe CHD and renal transplantation and compared these to admissions without CHD. There were 56 admissions for renal transplantation in the CHD group (0.04%) and 26,285 admissions in the group without CHD (0.21%, p<0.001). The CHD group were younger, had a higher proportion of Whites, longer length of stay, higher complication rates, higher in-hospital mortality, and higher costs. In conclusion, although renal transplantation is still relatively uncommon in the CHD population, there is an increasing recognition of severe chronic renal disease in the setting of CHD, making it important to understand the potential implications of these findings.12 month embargo; available online: 05 November 2022This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]