1,817 research outputs found
Skyglow: Towards a Night-time Illumination Model for Urban Environments
For night-time scenes in computer graphics there exist few consistent models or implementations for sky illumination, and those that do exist lack the feature of light pollution from artificial light sources. We present initial results for a physically-based night sky model including this "skyglow". Our model extends the existing models with the aforementioned "skyglow" from artificial light sources, using a technique derived from equations developed in the field of astronomy and adapted for a computer graphics context. Our current model has been implemented for Pixar’s RenderMan renderer and also been trialled with ShaderToy
Black Hole - Moving Mirror I: An Exact Correspondence
An exact correspondence is shown between a new moving mirror trajectory in
(1+1)D and a spacetime in (1+1)D in which a black hole forms from the collapse of
a null shell. It is shown that the Bogolubov coe cients between the \in" and \out"
states are identical and the exact Bogolubov coe cients are displayed. Generaliza-
tion to the (3+1)D black hole case is discusse
Diffusion and Home Range Parameters for Rodents: Peromyscus maniculatus in New Mexico
We analyze data from a long term field project in New Mexico, consisting of
repeated sessions of mark-recaptures of Peromyscus maniculatus (Rodentia:
Muridae), the host and reservoir of Sin Nombre Virus (Bunyaviridae:
Hantavirus). The displacements of the recaptured animals provide a means to
study their movement from a statistical point of view. We extract two
parameters from the data with the help of a simple model: the diffusion
constant of the rodents, and the size of their home range. The short time
behavior shows the motion to be approximately diffusive and the diffusion
constant to be 470+/-50m^2/day. The long time behavior provides an estimation
of the diameter of the rodent home ranges, with an average value of 100+/-25m.
As in previous investigations directed at Zygodontomys brevicauda observations
in Panama, we use a box model for home range estimation. We also use a harmonic
model in the present investigation to study the sensitivity of the conclusions
to the model used and find that both models lead to similar estimates.Comment: The published paper in Ecol. Complexity has an old version of Figure
6. Here we have put the correct version of Figure
South Carolina Bond for money between D. Goudelock and Anderson Pound[?], Union District, February 8, 1860. Signed by States Rights Gist and John R. R. Giles
$5000 South Carolina bond for money between D. Goudelock and Anderson Pound[?], Union District, February 8, 1860. Signed by States Rights Gist, John R. R. Giles, T.W.G. Giles and one other.https://digitalcommons.wofford.edu/littlejohnmss/1243/thumbnail.jp
Hadronic effects in leptonic systems: muonium hyperfine structure and anomalous magnetic moment of muon
Contributions of hadronic effects to the muonium physics and anomalous
magnetic moment of muon are considered. Special attention is paid to
higher-order effects and the uncertainty related to the hadronic contribution
to the hyperfine structure interval in the ground state of muonium.Comment: Presented at PSAS 2002 (St. Petersburg
A mirror world explanation for the Pioneer spacecraft anomalies?
We show that the anomalous acceleration of the Pioneer 10/11 spacecraft can
be explained if there is some mirror gas or mirror dust in our solar system.Comment: Latex, 7 pages, accepted in Phys. Lett.
A new model of the location of the plasmapause: CRRES results
A new empirical model of the plasmapause location has been developed using density data from the plasma wave receiver onboard the CRRES spacecraft for nearly 1000 orbits. The ‘‘plasmapause’’ is identified here as the innermost sharp gradient in density (change of a factor of 5 in <0.5 L). Such a sharp gradient was observed on 73% of the CRRES inbound and outbound orbits that returned data. The plasmapause location is expressed as a linear function of Kp (previous 12 hour maximum) and local time. The model gives the linear best fit location of the plasmapause as well as the standard deviations of the model parameters. We found a slight noon-midnight asymmetry with the plasmapause located on average an L shell farther from the Earth at midnight than in the noon sector. This is in the opposite sense to the noon-midnight asymmetry found previously. Significant variability (with standard deviations up to +/ 1 L shell) in the plasmapause location is seen and suggests that though the mean plasmapause is roughly circular, the instantaneous plasmapause has significant time variable localized structure at all local times but most especially in the duskside sectorPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/165337/1/Moldwin_CRRESresults_JGR2002.pdfSEL
Long-term patterns of excess mortality among endometrial cancer survivors
Background: We investigated excess mortality after endometrial cancer using conditional relative survival estimates and standardized mortality ratios (SMR). Methods: Women diagnosed with endometrial cancer during 2000-2017 (N ¼ 183,153) were identified in the Surveillance Epidemiology and End Results database. SMRs were calculated as observed deaths among endometrial cancer survivors over expected deaths among demographically similar women in the general U.S. population. Five-year relative survival was estimated at diagnosis and each additional year survived up to 12 years post-diagnosis, conditional on survival up to that year. Results: For the full cohort, 5-year relative survival was 87.7%, 96.2%, and 97.1% at 1, 5, and 10 years post-diagnosis, respectively. Conditional 5-year relative survival first exceeded 95%, reflecting minimal excess mortality compared with the general population, at 4 years post-diagnosis overall. However, in subgroup analyses, conditional relative survival remained lower for Black women (vs. White) and for those with regional/distant stage disease (vs. localized) throughout the study period. The overall SMR for all-cause mortality decreased from 5.90 [95% confidence interval (CI), 5.81-5.99] in the first year after diagnosis to 1.16 (95% CI, 1.13-1.19) at 10þ years; SMRs were consistently higher for non-White women and for those with higher stage or grade disease. Conclusions: Overall, endometrial cancer survivors had only a small survival deficit beyond 4 years post-diagnosis. However, excess mortality was greater in magnitude and persisted longer into survivorship for Black women and for those with more advanced disease. Impact: Strategies to mitigate disparities in mortality after endometrial cancer will be needed as the number of survivors continues to increase
The Discrepancy Between tau and e+e- Spectral Functions Revisited and the Consequences for the Muon Magnetic Anomaly
We revisit the procedure for comparing the pi pi spectral function measured
in tau decays to that obtained in e+e- annihilation. We re-examine the
isospin-breaking corrections using new experimental and theoretical input, and
find improved agreement between the tau- --> pi- pi0 nu_tau branching fraction
measurement and its prediction using the isospin-breaking-corrected e+e- -->
pi+pi- spectral function, though not resolving all discrepancies. We recompute
the lowest order hadronic contributions to the muon g-2 using e+e- and tau data
with the new corrections, and find a reduced difference between the two
evaluations. The new tau-based estimate of the muon magnetic anomaly is found
to be 1.9 standard deviations lower than the direct measurement.Comment: 10 pages, 6 figures, submitted to Eur. Phys. J. C; (v2): Revised
version with improved and uniform treatment of tau and e+e- data with
HVPTools and a few minor bug fixes; (v3): Final version accepted for
publicatio
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