10,495 research outputs found
Testing Game Theory in the Field: Swedish LUPI Lottery Games
Game theory is usually difficult to test precisely in the field because predictions typically
depend sensitively on features that are not controlled or observed. We conduct one such
test using field data from the Swedish lowest unique positive integer (LUPI) game. In the
LUPI game, players pick positive integers and whoever chose the lowest unique number
wins a fixed prize. Theoretical equilibrium predictions are derived assuming Poisson-
distributed uncertainty about the number of players, and tested using both field and
laboratory data. The field and lab data show similar patterns. Despite various deviations
from equilibrium, there is a surprising degree of convergence toward equilibrium. Some
of the deviations from equilibrium can be rationalized by a cognitive hierarchy model
Practical Color-Based Motion Capture
Motion capture systems have been widely used for high quality content creation and virtual reality but are rarely used in consumer applications due to their price and setup cost. In this paper, we propose a motion capture system built from commodity components that can be deployed in a matter of minutes. Our approach uses one or more webcams and a color shirt to track the upper-body at interactive rates. We describe a robust color calibration system that enables our color-based tracking to work against cluttered backgrounds and under multiple illuminants. We demonstrate our system in several real-world indoor and outdoor settings
Exact solution of a model of qubit dephasing due to telegraph noise
We present a general and exact formalism for finding the evolution of a
quantum system subject to external telegraph noise. The various qubit
decoherence rates are determined by the eigenvalues of a transfer matrix. The
formalism can be applied to a qubit subject to an arbitrary combination of
dephasing and relaxational telegraph noise, in contrast to existing
non-perturbative methods that treat only one or the other of these limits. We
present 3 applications: 1) We obtain the full qubit dynamics on time scales
short compared with the enviromental correlation times. In the strong coupling
cases this reveals unexpected oscillations and induced magnetization
components; 2) We find in strong coupling case strong violations of the widely
used relation 1/T = 1/2T + 1/T, which is a result of
perturbation theory; 3) We discuss the effects of bang-bang and spin-echo
controls of the qubit dynamics in general settings of the telegraph noises.
%The result shows that these methods are not very effective in %reducing
decoherence arising from a single telegraph noise. Finally, we discuss the
extension of the method to the cases of many telegraph noise sources and
multiple qubits. The method still works when white noise is also present.Comment: 7 pages, 6 figures, revised and extende
Long-term, low-dose lead exposure alters the gonadotropin-releasing hormone system in the male rat.
Lead is a male reproductive toxicant. Data suggest that rats dosed with relatively high levels of lead acetate for short periods of time induced changes in the hypothalamic gonadotropin-releasing hormone (GnRH) at the molecular level, but these changes were attenuated with increased concentration of exposure. The current study evaluated whether exposure to low levels of lead acetate over longer periods of time would produce a similar pattern of adaptation to toxicity at the molecular and biologic levels. Adult 100-day-old Sprague-Dawley male rats were dosed with 0, 0.025, 0.05, 0.1, and 0.3% lead acetate in water. Animals were killed after 1, 4, 8, and 16 weeks of treatment. Luteinzing hormone (LH) and GnRH levels were measured in serum, and lead levels were quantified in whole blood. Hypothalamic GnRH mRNA levels were also quantified. We found no significant differences in serum LH and GnRH among the groups of animals treated within each time period. A significant dose-related increase of GnRH mRNA concentrations with lead dosing occurred in animals treated for 1 week. Animals treated for more than 1 week also exhibited a significant increase in GnRH mRNA, but with an attenuation of the increase at the higher concentrations of lead with increased duration of exposure. We conclude that the signals within and between the hypothalamus and pituitary gland appear to be disrupted by long-term, low-dose lead exposure
Climatology of the U.S. Inter-Mountain West
The Inter-Mountain West (IMW) of North America is a region that lies between the Rocky Mountains to the east and the Cascades and Sierra Nevada to the west (Fig. 1). The climate of the IMW is generally semi-arid but this varies by location and elevation. An estimated 50- 80% of the IMW’s streams and rivers are fed by mountain snowpack (Marks and Winstral 2001), while the majority of the streams and rivers flow into desert sinks or closed-basin lakes such as the Great Salt Lake (Fig. 1). These streams and rivers create some agriculturally productive areas in the otherwise dry basins and mountain valleys. In particular, the Colorado River supplies water to the population-booming southwestern states and cities. Climate in the Colorado River Basin has been a subject of intense research due to its projected drying trend (Barnett and Pierce 2008). Change in winter precipitation regime (i.e. ratio between rainfall and snowfall) is also a subject of interest not only because its role in water resource but also its impact on recreational (ski) industry in the IMW.https://digitalcommons.usu.edu/modern_climatology/1005/thumbnail.jp
A Critical Examination of Hypernova Remnant Candidates in M101. II. NGC 5471B
NGC 5471B has been suggested to contain a hypernova remnant because of its
extraordinarily bright X-ray emission. To assess its true nature, we have
obtained high-resolution images in continuum bands and nebular lines with the
Hubble Space Telescope, and high-dispersion long-slit spectra with the Kitt
Peak National Observatory 4-m echelle spectrograph. The images reveal three
supernova remnant (SNR) candidates in the giant HII region NGC 5471, with the
brightest one being the 77x60 pc shell in NGC 5471B. The Ha velocity profile of
NGC 5471B can be decomposed into a narrow component (FWHM = 41 km/s) from the
background HII region and a broad component (FWHM = 148 km/s) from the SNR
shell. Using the brightness ratio of the broad to narrow components and the Ha
flux measured from the WFPC2 Ha image, we derive an Ha luminosity of
(1.4+-0.1)x10^39 ergs/s for the SNR shell. The [SII]6716,6731 doublet ratio of
the broad velocity component is used to derive an electron density of ~700
cm^-3 in the SNR shell. The mass of the SNR shell is thus 4600+-500 Mo. With a
\~330 km/s expansion velocity implied by the extreme velocity extent of the
broad component, the kinetic energy of the SNR shell is determined to be
5x10^51 ergs. This requires an explosion energy greater than 10^52 ergs, which
can be provided by one hypernova or multiple supernovae. Comparing to SNRs in
nearby active star formation regions, the SNR shell in NGC 5471B appears truly
unique and energetic. We conclude that the optical observations support the
existence of a hypernova remnant in NGC 5471B.Comment: 27 pages, 9 figures, to appear in May 2002 issue of The Astronomical
Journa
Properties of Veneer and Veneer-Based Products from Genetically Improved White Spruce Plantations
This study examined the suitability of genetically improved fast-growing and short-rotation plantations for veneer-based products. The materials came from a 36-year-old white spruce (Picea glauca) half-sib progeny/provenance trial located in two regions (sites) of Quebec. A total of 270 sample trees were collected for the study, 130 trees from St-Ignace in the Gaspé Region and 140 trees from Valcartier near Quebec City. Veneer from the Valcartier site had a mean wood density of 0.353 g/cm3 and a mean modulus of elasticity (MOE) of 9.48 GPa (1.375 million psi). Veneer from the St-Ignace site had a mean wood density of 0.345 g/cm3] and a mean MOE of 8.05 GPa (1.167 million psi). The differences in veneer wood density and MOE between the two sites were statistically significant. Compared to other Canadian species commonly used for veneer products, the genetically improved fast-growing and short-rotation white spruce yielded considerably lower veneer stiffness.The plantation-grown white spruce veneer from both sites was knotty. Ninety-eight percent of the veneer was classified as visual grade C. The visually graded veneer would be suitable for sheathing grade plywood. With proper stress grading, 14% of the white spruce veneer was suitable for 12.41 GPa (1.8 million psi) grade laminated veneer lumber (LVL), and another 24% of the veneer was suitable for a lower 10.34 GPa (1.5 million psi) grade of LVL, or as core plies for LVL manufacture. The remaining 62% of the stress-graded veneer was suitable for sheathing grade plywood
Extraction of Text from Optic Nerve Optical Coherence Tomography Reports
Purpose: The purpose of this study was to develop and evaluate rule-based
algorithms to enhance the extraction of text data, including retinal nerve
fiber layer (RNFL) values and other ganglion cell count (GCC) data, from Zeiss
Cirrus optical coherence tomography (OCT) scan reports. Methods: DICOM files
that contained encapsulated PDF reports with RNFL or Ganglion Cell in their
document titles were identified from a clinical imaging repository at a single
academic ophthalmic center. PDF reports were then converted into image files
and processed using the PaddleOCR Python package for optical character
recognition. Rule-based algorithms were designed and iteratively optimized for
improved performance in extracting RNFL and GCC data. Evaluation of the
algorithms was conducted through manual review of a set of RNFL and GCC
reports. Results: The developed algorithms demonstrated high precision in
extracting data from both RNFL and GCC scans. Precision was slightly better for
the right eye in RNFL extraction (OD: 0.9803 vs. OS: 0.9046), and for the left
eye in GCC extraction (OD: 0.9567 vs. OS: 0.9677). Some values presented more
challenges in extraction, particularly clock hours 5 and 6 for RNFL thickness,
and signal strength for GCC. Conclusions: A customized optical character
recognition algorithm can identify numeric results from optical coherence scan
reports with high precision. Automated processing of PDF reports can greatly
reduce the time to extract OCT results on a large scale
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