753 research outputs found
Proportion estimation using prior cluster purities
The prior distribution of CLASSY component purities is studied, and this information incorporated into maximum likelihood crop proportion estimators. The method is tested on Transition Year spring small grain segments
An algorithm for the rapid location of an extreme of a function subject only to geometric restrictions
The requirements of symmetry and convexity in the application of algorithms for the minimization or maximization of a function are discussed. It is argued that if a function of a single variable is convex and symmetric in a neighborhood of an extremum, the extremum may be approximated to the precision that increases by at least a power of two per functional evaluation. The procedure may be used to drive a complex optimization procedure in the multivariate area estimation problem encountered in remote sensing
Evaluating the Use of Analyst Labels in Maximum Likelihood Cluster Proportion Estimation
There are no author-identified significant results in this report
A bound for the smoothing parameter in certain well-known nonparametric density estimators
Two classes of nonparametric density estimators, the histogram and the kernel estimator, both require a choice of smoothing parameter, or 'window width'. The optimum choice of this parameter is in general very difficult. An upper bound to the choices that depends only on the standard deviation of the distribution is described
Minimum variance geographic sampling
Resource inventories require samples with geographical scatter, sometimes not as widely spaced as would be hoped. A simple model of correlation over distances is used to create a minimum variance unbiased estimate population means. The fitting procedure is illustrated from data used to estimate Missouri corn acreage
A note on the generation of Poisson-distributed random numbers with large mean
There are no author-identified significant results in this report
Developing an After-School Program to Increase STEM Interest, Awareness and Knowledge of Minority Females in a Title I Middle School
Educators, politicians and industry professionals note that the number of opportunities for workers in the science, technology, engineering and math (STEM) fields grow exponentially over time. Accordingly, emphasis is placed on our schools to produce graduates capable of filling these positions. While these efforts are promising, there is a notable absence of females and minorities in the STEM professions. In an attempt to understand the reasons for this disparity, many educators believe a lack of interest in the STEM field begins at an early age, and disenfranchised students are not afforded the opportunities given to students in more affluent areas of a school district, city or state. This study investigated this issue by developing and delivering a series of STEM-focused after-school workshops at a Title 1 middle school in West Palm Beach, Florida. These workshops were presented by STEM professionals from the South Florida Science Center and Aquarium, local schools, industry and businesses. Sixth-grade students, primarily from an ethnic minority, low socio-economic background, were recruited for these workshops, with their STEM awareness and interest tracked over the entirety of a school year. Results showed a significant increase in the constructs measures. These results can contribute to a higher quality of life by opening educational and occupational opportunities previously unknown or misunderstood by the participants, their families and communities
Adult BMI change and risk of Breast Cancer: National Health and Nutrition Examination Survey (NHANES) 2005-2010
OBJECTIVE: Breast cancer is the second leading cause of cancer mortality among women in the developed world. This study assessed the association between occurrence of breast cancer and body mass index (BMI) change from age 25 to age closest to breast cancer diagnosis while exploring the modifying effects of demographic variables.
METHODS: The National Health and Nutrition Examination Survey data were used. Women included were ≥50 years, not pregnant and without a diagnosis of any cancer but breast. The total sample included 2895 women (172 with breast cancer and 2723 controls with no breast cancer diagnosis). Multivariate logistic regression was used to estimate the OR and 95 % CIs and interaction evaluated by including an interaction term in the model.
RESULTS: Women whose BMI increased from normal or overweight to obese compared to those who remained at a normal BMI were found to have a 2 times higher odds (OR = 2.1; 95 % CI 1.11-3.79) of developing breast cancer. No significant association was observed for women who increased to overweight. However, a more pronounced association was observed in non-Hispanic black women (OR = 6.6; 95 % CI 1.68-25.86) and a significant association observed when they increased from normal to overweight (OR = 4.2; 95 % CI 1.02-17.75).
CONCLUSIONS: Becoming obese after age 25 is associated with increased risk of breast cancer in women over 50 years old, with non-Hispanic black women being at greatest risk
The Interplanetary Network Supplement to the BeppoSAX Gamma-Ray Burst Catalogs
Between 1996 July and 2002 April, one or more spacecraft of the
interplanetary network detected 787 cosmic gamma-ray bursts that were also
detected by the Gamma-Ray Burst Monitor and/or Wide-Field X-Ray Camera
experiments aboard the BeppoSAX spacecraft. During this period, the network
consisted of up to six spacecraft, and using triangulation, the localizations
of 475 bursts were obtained. We present the localization data for these events.Comment: 89 pages, 3 figures. Submitted to the Astrophysical Journal
Supplement Serie
APASS Landolt-Sloan BVgri photometry of RAVE stars. I. Data, effective temperatures and reddenings
We provide APASS photometry in the Landolt BV and Sloan g'r'i' bands for all
the 425,743 stars included in the latest 4th RAVE Data Release. The internal
accuracy of the APASS photometry of RAVE stars, expressed as error of the mean
of data obtained and separately calibrated over a median of 4 distinct
observing epochs and distributed between 2009 and 2013, is 0.013, 0.012, 0.012,
0.014 and 0.021 mag for B, V, g', r' and i' band, respectively. The equally
high external accuracy of APASS photometry has been verified on secondary
Landolt and Sloan photometric standard stars not involved in the APASS
calibration process, and on a large body of literature data on field and
cluster stars, confirming the absence of offsets and trends. Compared with the
Carlsberg Meridian Catalog (CMC-15), APASS astrometry of RAVE stars is accurate
to a median value of 0.098 arcsec. Brightness distribution functions for the
RAVE stars have been derived in all bands. APASS photometry of RAVE stars,
augmented by 2MASS JHK infrared data, has been chi2 fitted to a densely
populated synthetic photometric library designed to widely explore in
temperature, surface gravity, metallicity and reddening. Resulting Teff and
E(B-V), computed over a range of options, are provided and discussed, and will
be kept updated in response to future APASS and RAVE data releases. In the
process it is found that the reddening caused by an homogeneous slab of dust,
extending for 140 pc on either side of the Galactic plane and responsible for
E(B-V,poles)=0.036 +/- 0.002 at the galactic poles, is a suitable approximation
of the actual reddening encountered at Galactic latitudes |b|>=25 deg.Comment: Astronomical Journal, in press. Resolution of Figures degrated to
match arXiv file size limit
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