928 research outputs found
Artificial intelligence for heart rate variability analyzing with arrhythmias
Introduction. Existing standards of Heart Rate Variability (HRV) technology limit its use to sinus rhythm. A small number of extrasystoles is allowed, if the device used has special procedures for the detection and replacement of ectopic complexes. However, it is important to expand the indicated limits of the applicability of the HRV technology. This specially regards the cases when the HRV technology looks promising in the diagnostics, as, for example, in atrial fibrillation and atrial flutter.
Materials and Methods. All ECG measurements were performed on XAI-MEDICA® equipment and software. Processing of the obtained RR Series was carried out using the software Kubios® HRV Standard. All recommended HRV characteristics for Time-Domain, Frequency-Domain and Nonlinear were calculated.
The purpose of the work. The article presents an artificial intelligence (AI) procedure for detecting episodes of arrhythmias
and reconstruction of core patient’s rhythm, and demonstrates the efficacy of its use for the HRV analysis in patients with varying degrees of arrhythmias.
The results of the study. It was shown efficiency of developed artificial intelligence procedure for HRV analyzing of patients with different level of arrhythmias. These were demonstrated for Time-Domain, Frequency-Domain and Nonlinear methods. The direct inclusion into review of Arrhythmia Episodes and the use of the initial RR Series leads to a significant distortion of the results of the HRV analysis for the whole set of methods and for all considered options for arrhythmia.
Conclusion. High efficacy of operation of the procedure AI core rhythm extraction from initial RR Series for patients with arrhythmia was reported in all cases
Self-energy correction to the bound-electron g factor in H-like ions
The one-loop self-energy correction to the 1s electron g factor is evaluated
to all orders in Z\alpha with an accuracy, which is essentially better than
that of previous calculations of this correction. As a result, the uncertainty
of the theoretical prediction for the bound-electron g factor in H-like carbon
is reduced by a factor of 3. This improves the total accuracy of the recent
electron-mass determination [Beier et al. Phys. Rev. Lett. 88, 011603 (2002)].
The new value of the electron mass is found to be m_e = 0.000 548 579 909 3(3)
u
The light-by-light contribution to the muon anomalous magnetic moment from the axial-vector mesons exchanges within the nonlocal quark model
The contribution of axial-vector mesons to the muon's anomalous magnetic
moment through a light-by-light process is considered within a nonlocal quark
model. The model is based on a four-quark interaction with scalar--pseudoscalar
and vector--axial-vector sectors. While the transverse component of the
axial-vector corresponds to a spin-1 particle, the unphysical longitudinal
component is mixed with a pseudoscalar meson. The model parameters are
re-fitted to the pion properties in the presence of pi-a_1 mixing. The obtained
estimation for the light-by-light contribution of a_1+f_1 mesons is
(3.6+-1.8)*10^{-11}.Comment: 18 pages, 10 figures, final version accepted for publication in
Physical Review
Muonic hydrogen ground state hyperfine splitting
Corrections of orders alpha^5, alpha^6 are calculated in the hyperfine
splitting of the muonic hydrogen ground state. The nuclear structure effects
are taken into account in the one- and two-loop Feynman amplitudes by means of
the proton electromagnetic form factors. The modification of the hyperfine
splitting part of the Breit potential due to the electron vacuum polarization
is considered. Total numerical value of the 1S state hyperfine splitting
182.638 meV in the (mu p) can play the role of proper estimation for the
corresponding experiment with the accuracy 30 ppm.Comment: 18 pages, Talk presented at the 11th Lomonosov Conference on
Elementary Particle Physics, Moscow State University, August 200
Hadronic Production of Doubly Charmed Baryons via Charm Exitation in Proton
The production of baryons containing two charmed quarks Xi_cc in hadronic
interactions at high energies and large transverse momenta is considered. It is
supposed, that Xi_cc-baryon is formed during a non-perturbative fragmentation
of the (cc)-diquark, which was produced in the hard process of -quark
scattering from the colliding protons: c+c -> (cc) +g. It is shown that such
mechanism enhances the expected doubly charmed baryon production cross section
on Tevatron and LHC colliders approximately 2 times in contrast to predictions,
obtained in the model of gluon - gluon production of (cc)-diquarks in the
leading order of perturbative QCD.Comment: LaTeX2e, 13 pages plus 4 fig. using revtex4.sty, epsfig.sty. Talk was
presented at International Seminar on Physics of Fundamental Interactions in
ITEP, Moscow, Russia, November 27 - December 1, 200
Lamb shift in muonic deuterium atom
We present new investigation of the Lamb shift (2P_{1/2}-2S_{1/2}) in muonic
deuterium (mu d) atom using the three-dimensional quasipotential method in
quantum electrodynamics. The vacuum polarization, nuclear structure and recoil
effects are calculated with the account of contributions of orders alpha^3,
alpha^4, alpha^5 and alpha^6. The results are compared with earlier performed
calculations. The obtained numerical value of the Lamb shift 202.4139 meV can
be considered as a reliable estimate for the comparison with forthcoming
experimental data.Comment: 24 pages, 11 figures. arXiv admin note: text overlap with
arXiv:hep-ph/061229
One-loop corrections of order (Z alpha)^6m_1/m_2, (Z alpha)^7 to the muonium fine structure
The corrections of order (Z alpha)^6m_1/m_2 and (Z alpha)^7 from one-loop
two-photon exchange diagrams to the energy spectra of the hydrogenic atoms are
calculated with the help of the Taylor expansion of corresponding integrands.
The method of averaging the quasipotential over the wave functions in the
d-dimensional coordinate space is formulated. The numerical values of the
obtained contributions to the fine structure of muonium, hydrogen and
positronium are presented.Comment: Talk given at the XVIth International Workshop High-Energy Physics
and Quantum Field Theory (QFTHEP2001), Moscow, Russia, 6-12 Sep 2001, 12
pages, REVTE
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