27,075 research outputs found
Interelectronic-interaction effect on the transition probability in high-Z He-like ions
The interelectronic-interaction effect on the transition probabilities in
high-Z He-like ions is investigated within a systematic quantum electrodynamic
approach. The calculation formulas for the interelectronic-interaction
corrections of first order in 1/Z are derived using the two-time Green function
method. These formulas are employed for numerical evaluations of the magnetic
transition probabilities in heliumlike ions. The results of the calculations
are compared with experimental values and previous calculations
Continuity theorems for the queueing system
In this paper continuity theorems are established for the number of losses
during a busy period of the queue. We consider an queueing
system where the service time probability distribution, slightly different in a
certain sense from the exponential distribution, is approximated by that
exponential distribution. Continuity theorems are obtained in the form of one
or two-sided stochastic inequalities. The paper shows how the bounds of these
inequalities are changed if further assumptions, associated with specific
properties of the service time distribution (precisely described in the paper),
are made. Specifically, some parametric families of service time distributions
are discussed, and the paper establishes uniform estimates (given for all
possible values of the parameter) and local estimates (where the parameter is
fixed and takes only the given value). The analysis of the paper is based on
the level crossing approach and some characterization properties of the
exponential distribution.Comment: Final revision; will be published as i
On Bayesian inference with conjugate priors for scale mixtures of normal distributions
Bayesian inference is considered for the multivariate regression model with distribution of the random responses belonging to the multivariate scale mixtures of normal distributions. The posterior distribution of the regression parameters and the predictive distribution of future responses for the model are derived when the prior distribution of the parameters is from the conjugate family and they are shown to be identical to those obtained under normally distributed random responses. This gives inference robustness with respect to departures from the reference case of independent sampling from the normal distribution
Hadronic final state interactions at ALEPH and OPAL
The studies of Fermi-Dirac correlations of and
pairs in hadronic decays,
Bose-Einstein correlations and colour reconnection in -pairs decays
performed by the ALEPH collaboration in annihilation at LEP
are presented. The OPAL analysis of Bose-Einstein correlations in
-pair decays is also discussed.Comment: 5 pages, 5 figures; LaTeX (espcrc2.sty). Talk presented at QCD'99,
Montpellier, 7-13 July 1999. To appear in Nucl. Phys. B (Proc. Suppl.
Independent measurement of the top quark mass and the light- and bottom-jet energy scales at hadron colliders
A method for the simultaneous determination of the energy scales for b-quark
jets and light jets, the jet energy resolution, and the top quark mass at
hadron colliders is presented. The method exploits the unique kinematics of
events with top-antitop pair production, where one of the top quarks involves a
leptonic and one a hadronic W boson decay. The paper shows a feasibility study
of how this simultaneous measurement can be performed at the upcoming LHC
experiments ATLAS and CMS.Comment: 10 pages, 5 figure
Relativistic calculations of isotope shifts in highly charged ions
The isotope shifts of forbidden transitions in Be- and B-like argon ions are
calculated. It is shown that only using the relativistic recoil operator can
provide a proper evaluation of the mass isotope shift, which strongly dominates
over the field isotope shift for the ions under consideration. Comparing the
isotope shifts calculated with the current experimental uncertainties indicates
very good perspectives for a first test of the relativistic theory of the
recoil effect in middle-Z ions
Approximations of the Generalized Wilks' Distribution
Wilks' lambda and the corresponding Wilks' distribution are well known concepts in testing in multivariate regression models.The topic of this paper is a generalization of the Wilks distribution.This generalized Wilks' distribution is relevant for testing in multivariate regression models with monotone missing data.Just as the (usual) Wilks distribution can be approximated by the x2-distribution of Bartlett (1947), the generalized Wilks' distribution can be approximated by x2-distributions in more or less the same way.We use Box transformations to derive the x2-approximations and compare them by simulation.approximation theory;distribution;models;simulation
Using evidence combination for transformer defect diagnosis
This paper describes a number of methods of evidence combination, and their applicability to the domain of transformer defect diagnosis. It explains how evidence combination fits into an on-line and implemented agent-based condition monitoring system, and the benefits of giving selected agents reflective abilities. Reflection has not previously been deployed in an industrial setting, and theoretical work has been in domains other than power engineering. This paper presents the results of implementing five different methods of evidence combination, showing that reflective techniques give greater accuracy than non-reflective
In-plane fluxon in layered superconductors with arbitrary number of layers
I derive an approximate analytic solution for the in-plane vortex (fluxon) in
layered superconductors and stacked Josephson junctions (SJJ's) with arbitrary
number of layers. The validity of the solution is verified by numerical
simulation. It is shown that in SJJ's with large number of thin layers,
phase/current and magnetic field of the fluxon are decoupled from each other.
The variation of phase/current is confined within the Josephson penetration
depth, , along the layers, while magnetic field decays at the
effective London penetration depth, . For comparison
with real high- superconducting samples, large scale numerical simulations
with up to 600 SJJ's and with in-plane length up to 4000 %, are
presented. It is shown, that the most striking feature of the fluxon is a
Josephson core, manifesting itself as a sharp peak in magnetic induction at the
fluxon center.Comment: 4 pages, 4 figures. Was presented in part at the First Euroconference
on Vortex Matter in Superconductors (Crete, September 1999
Virtual Trauma Team
The clinical motivation for Virtual Trauma Team is to improve quality of care in trauma care in the vital first "golden hour" where correct intervention can greatly improve likely health outcome.
The motivation for Virtual Homecare Team is to improve quality of life and independence for patients by supporting care at home. The economic motivation is to replace expensive hospital-based care with homecare using wireless technology to support the patient and the carers.
Results will be applied by international partners in healthcare service
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