15,847 research outputs found
Poisson transition rates from time-domain measurements with finite bandwidth
In time-domain measurements of a Poisson two-level system, the observed
transition rates are always smaller than those of the actual system, a general
consequence of finite measurement bandwidth in an experiment. This
underestimation of the rates is significant even when the measurement and
detection apparatus is ten times faster than the process under study. We derive
here a quantitative form for this correction using a straightforward
state-transition model that includes the detection apparatus, and provide a
method for determining a system's actual transition rates from
bandwidth-limited measurements. We support our results with computer
simulations and experimental data from time-domain measurements of
quasiparticle tunneling in a single-Cooper-pair transistor.Comment: 4 pages, 5 figure
A TRANSLOG COST FUNCTION ANALYSIS OF U.S. AGRICULTURE: A DYNAMIC SPECIFICATION
This study has used an empirical approach developed by Urga and Walters (2003) to examine the implications of the short-run specification of the standard translog cost specification along with the possible implications of non-stationarity. We have estimated a dynamic translog cost specification complete with dynamic share equations for U.S. agriculture and compared it to the static, long-run specification. We found that the dynamic translog specification yielded more significant parameter estimates, and yielded results that are consistent with economic theory. In particular, the coefficient m (the adjustment cost parameter) determines the overall autoregressive structure of the model. The fact that its estimated value (0.36) is statistically different from zero at any conventional level of confidence indicates that the dynamic structure of the model is important. This finding illustrates the superiority of the short-run, dynamic specification over the static, long-run model.Agribusiness,
A Translog Cost Function Analysis of U.S. Agriculture: 1948-1999
This study examines the implications of the short-run specification of the standard, static translog cost function along with the possible implications of non-stationarity by estimating a dynamic translog cost specification complete with dynamic share equations for the U.S. using an empirical approach developed by Urga and Walters (2003). We compare the results of the static, long-run model with those of a dynamic, short-run error-correction model in terms of 1) significance of the parameter estimates, and 2) consistency with economic theory.Research Methods/ Statistical Methods,
Validation of the CMS Magnetic Field Map
The Compact Muon Solenoid (CMS) is a general purpose detector, designed to
run at the highest luminosity at the CERN Large Hadron Collider (LHC). Its
distinctive features include a 4 T superconducting solenoid with 6-m-diameter
by 12.5-m-length free bore, enclosed inside a 10,000-ton return yoke made of
construction steel. The return yoke consists of five dodecagonal three-layered
barrel wheels and four end-cap disks at each end comprised of steel blocks up
to 620 mm thick, which serve as the absorber plates of the muon detection
system. To measure the field in and around the steel, a system of 22 flux loops
and 82 3-D Hall sensors is installed on the return yoke blocks. A TOSCA 3-D
model of the CMS magnet is developed to describe the magnetic field everywhere
outside the tracking volume measured with the field-mapping machine. The
magnetic field description is compared with the measurements and discussed.Comment: 7 pages, 5 figures, presented at 4th International Conference on
Superconductivity and Magnetism 2014, April 27 - May 2, 2014, Antalya,
Turkey. arXiv admin note: substantial text overlap with arXiv:1605.08778;
text overlap with arXiv:1212.165
A New Study of the Polarized Parton Densities in the Nucleon
We present a new next-to-leading order QCD analysis of the world data on
inclusive polarized deep inelastic lepton-nucleon scattering adding to the old
set of data the final SMC results, the HERMES proton and very recent SLAC/E155
deuteron data. We find an excellent fit to the data and present results for the
polarized parton densities in different factorization schemes. These results
are in a good agreement with what follows from the theory. We have also found
that the main effect of the newly incorporated data is a better determination
of the polarized gluon density.Comment: 9 pages, latex, 5 ps figures Presented at the 7th International
Workshop on Deep Inelastic Scattering and QCD, Zeuthen, Germany, April 19-23,
199
The incidence of pathogens in honey bee (Apis mellifera L) colonies in Finland and Great Britain
Dead adult bees collected from 26 apiaries distributed throughout Southern Finland were examined for protozoan, microsporidian and viral pathogens. Malpighamoeba mellificae was not found, but Nosema apis was detected at low levels in 11 of the 39 samples examined. Of the 51 samples examined for viruses, bee virus Y was detected in 2, cloudy wing virus in 14 and filamentous virus in 13. These findings are compared with pathogen incidence in honey bee colonies in Britain and discussed with reference to winter losses and Varroa jacobsoni infestation
Iridovirus from bees
An iridovirus, Apis iridescent virus (AIV), isolated from sick adult specimens of Apis cerana (Hymenoptera) from Kashmir, closely resembles iridescent viruses from Tipula and Sericesthis spp. (TIV and SIV). However, AIV is only distantly related serologically to TIV and SIV and is even moderately related to several other similar viruses that were tested in tube precipitation tests with intact particles. AIV multiplied in Apis mellifera, forming cytoplasmic iridescent crystalline aggregates in several tissues, but unlike all the other iridoviruses tested, it failed to multiply in Galleria mellonella
Twist-2 Light-Cone Pion Wave Function
We present an analysis of the existing constraints for the twist-2 light-cone
pion wave function. We find that existing information on the pion wave function
does not exclude the possibility that the pion wave function attains its
asymptotic form. New bounds on the parameters of the pion wave function are
presented.Comment: 7 pages, LaTeX, 1 PS-figure, one reference added, minor changes in
the tex
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