7,660 research outputs found
Estimation for Nonlinear Dynamical Systems over Packet-Dropping Networks
Two approaches, extended Kalman filter (EKF) and moving horizon estimation (MHE), are discussed for state estimation for nonlinear dynamical systems over packet-dropping networks. For EKF, we provide sufficient conditions that guarantee a bounded EKF error covariance. For MHE, a natural scheme on organizing the finite horizon window is proposed to handle intermittent observations. A nonlinear programming software package, SNOPT, is employed in MHE and the formulation for constraints is discussed in detail. Examples and simulation results are presented
Modeling of negative autoregulated genetic networks in single cells
We discuss recent developments in the modeling of negative autoregulated
genetic networks. In particular, we consider the temporal evolution of the
population of mRNA and proteins in simple networks using rate equations. In the
limit of low copy numbers, fluctuation effects become significant and more
adequate modeling is then achieved using the master equation formalism. The
analogy between regulatory gene networks and chemical reaction networks on dust
grains in the interstellar medium is discussed. The analysis and simulation of
complex reaction networks are also considered.Comment: 15 pages, 4 figures. Published in Gen
Performance and Radiation Testing of a Low-Noise Switched Capacitor Array for the CMS Endcap Muon System.
The 16-channel, 96-cell per channel switched capacitor array ( SCA) ASIC developed at UC Davis for the cathode readout of the cathode strip chambers ( CSC) in the CMS endcap muon system is ready for production. For the final full-sized prototype, the Address Decoder was re-designed and LVDS receivers were incorporated into the chip package. Under precision testing, the chip exhibits excellent linearity within the 1V design range and very low cell-to-cell pedestal variation. Monitored samples of the production design were subjected to exposure to a 63.3 MeV proton beam. The performance of chips after exposures up to 100 krad was within tolerances of an unexposed part
Effects of in-medium vector meson masses on low-mass dileptons from SPS heavy-ion collisions
Using a relativistic transport model to describe the expansion of the
fire-cylinder formed in the initial stage of heavy-ion collisions at SPS/CERN
energies, we study the production of dileptons with mass below about 1 GeV from
these collisions. The initial hadron abundance and their momentum distributions
in the fire-cylinder are determined by following the general features of the
results from microscopic models based on the string dynamics and further
requiring that the final proton and pion spectra and rapidity distributions are
in agreement with available experimental data. For dilepton production, we
include the Dalitz decay of , , , and
mesons, the direct decay of primary , and mesons, and
the pion-pion annihilation that proceeds through the meson, the
pion-rho annihilation that proceeds through the meson, and the
kaon-antikaon annihilation that proceeds through the meson. We find that
the modification of vector meson properties, especially the decrease of their
mass due to the partial restoration of chiral symmetry, in hot and dense
hadronic matter, provides a quantitative explanation of the recently observed
enhancement of low-mass dileptons by the CERES collaboration in central S+Au
collisions and by the HELIOS-3 collaboration in central S+W collisions.Comment: 46 pages, LaTeX, figures available from [email protected], to appear
in Nucl. Phys.
GP-SUM. Gaussian Processes Filtering of non-Gaussian Beliefs
This work studies the problem of stochastic dynamic filtering and state
propagation with complex beliefs. The main contribution is GP-SUM, a filtering
algorithm tailored to dynamic systems and observation models expressed as
Gaussian Processes (GP), and to states represented as a weighted sum of
Gaussians. The key attribute of GP-SUM is that it does not rely on
linearizations of the dynamic or observation models, or on unimodal Gaussian
approximations of the belief, hence enables tracking complex state
distributions. The algorithm can be seen as a combination of a sampling-based
filter with a probabilistic Bayes filter. On the one hand, GP-SUM operates by
sampling the state distribution and propagating each sample through the dynamic
system and observation models. On the other hand, it achieves effective
sampling and accurate probabilistic propagation by relying on the GP form of
the system, and the sum-of-Gaussian form of the belief. We show that GP-SUM
outperforms several GP-Bayes and Particle Filters on a standard benchmark. We
also demonstrate its use in a pushing task, predicting with experimental
accuracy the naturally occurring non-Gaussian distributions.Comment: WAFR 2018, 16 pages, 7 figure
Enhancement of low-mass dileptons in heavy-ion collisions
Using a relativistic transport model for the expansion stage of S+Au
collisions at 200 GeV/nucleon, we show that the recently observed enhancement
of low-mass dileptons by the CERES collaboration can be explained by the
decrease of vector meson masses in hot and dense hadronic matter.Comment: 12 pages, RevTeX, 3 figures available from [email protected]
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Curation of the End-of-Term Web Archive
Paper for the 2011 IS&T Archiving Conference. This paper discusses the Classification of the End-of-Term Archive research project at the University of North Texas
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