1,616 research outputs found
Discrimination of the Healthy and Sick Cardiac Autonomic Nervous System by a New Wavelet Analysis of Heartbeat Intervals
We demonstrate that it is possible to distinguish with a complete certainty
between healthy subjects and patients with various dysfunctions of the cardiac
nervous system by way of multiresolutional wavelet transform of RR intervals.
We repeated the study of Thurner et al on different ensemble of subjects. We
show that reconstructed series using a filter which discards wavelet
coefficients related with higher scales enables one to classify individuals for
which the method otherwise is inconclusive. We suggest a delimiting diagnostic
value of the standard deviation of the filtered, reconstructed RR interval time
series in the range of (for the above mentioned filter), below
which individuals are at risk.Comment: 5 latex pages (including 6 figures). Accepted in Fractal
Topological model of soap froth evolution with deterministic T2-processes
We introduce a topological model for the evolution of 2d soap froth. The
topological rearrangements (T2 processes) are deterministic (unlike the
standard stochastic model): the final topology depends on the areas of the
neighboring cells. The new model gives agreement with experiments in the
transient regime, where the previous models failed qualitatively, and also
improves agreement in the scaling state.Comment: latex, 12 pages, 2 figure
Inverse eigenvalue problem for discrete three-diagonal Sturm-Liouville operator and the continuum limit
In present article the self-contained derivation of eigenvalue inverse
problem results is given by using a discrete approximation of the Schroedinger
operator on a bounded interval as a finite three-diagonal symmetric Jacobi
matrix. This derivation is more correct in comparison with previous works which
used only single-diagonal matrix. It is demonstrated that inverse problem
procedure is nothing else than well known Gram-Schmidt orthonormalization in
Euclidean space for special vectors numbered by the space coordinate index. All
the results of usual inverse problem with continuous coordinate are reobtained
by employing a limiting procedure, including the Goursat problem -- equation in
partial derivatives for the solutions of the inversion integral equation.Comment: 19 pages There were made some additions (and reformulations) to the
text making the derivation of the results more precise and understandabl
Inverse Spectral-Scattering Problem with Two Sets of Discrete Spectra for the Radial Schroedinger Equation
The Schroedinger equation on the half line is considered with a real-valued,
integrable potential having a finite first moment. It is shown that the
potential and the boundary conditions are uniquely determined by the data
containing the discrete eigenvalues for a boundary condition at the origin, the
continuous part of the spectral measure for that boundary condition, and a
subset of the discrete eigenvalues for a different boundary condition. This
result extends the celebrated two-spectrum uniqueness theorem of Borg and
Marchenko to the case where there is also a continuous spectru
Cluster Persistence: a Discriminating Probe of Soap Froth Dynamics
The persistent decay of bubble clusters in coarsening two-dimensional soap
froths is measured experimentally as a function of cluster volume fraction.
Dramatically stronger decay is observed in comparison to soap froth models and
to measurements and calculations of persistence in other systems. The fraction
of individual bubbles that contain any persistent area also decays, implying
significant bubble motion and suggesting that T1 processes play an important
role in froth persistence.Comment: 5 pages, revtex, 4 eps figures. To appear in Europhys. Let
Primordial pairing and binding of superheavy charge particles in the early Universe
Primordial superheavy particles, considered as the source of Ultra High
Energy Cosmic Rays (UHECR) and produced in local processes in the early
Universe, should bear some strictly or approximately conserved charge to be
sufficiently stable to survive to the present time. Charge conservation makes
them to be produced in pairs, and the estimated separation of particle and
antiparticle in such pair is shown to be in some cases much smaller than the
average separation determined by the averaged number density of considered
particles. If the new U(1) charge is the source of a long range field similar
to electromagnetic field, the particle and antiparticle, possessing that
charge, can form primordial bound system with annihilation timescale, which can
satisfy the conditions, assumed for this type of UHECR sources. These
conditions severely constrain the possible properties of considered particles.Comment: Latex, 4 pages. The final version to appear in Pis'ma ZhETF (the
conditions for the primordial binding are specified, some refs added
The fastest unbound star in our Galaxy ejected by a thermonuclear supernova
Hypervelocity stars (HVS) travel with velocities so high, that they exceed
the escape velocity of the Galaxy. Several acceleration mechanisms have been
discussed. Only one HVS (US 708, HVS 2) is a compact helium star. Here we
present a spectroscopic and kinematic analysis of US\,708. Travelling with a
velocity of , it is the fastest unbound star in our
Galaxy. In reconstructing its trajectory, the Galactic center becomes very
unlikely as an origin, which is hardly consistent with the most favored
ejection mechanism for the other HVS. Furthermore, we discovered US\,708 to be
a fast rotator. According to our binary evolution model it was spun-up by tidal
interaction in a close binary and is likely to be the ejected donor remnant of
a thermonuclear supernova.Comment: 16 pages report, 20 pages supplementary material
Development of teacher’s language personality in the modern information and educational environment of the university
Цель: исследовать структуру и содержание развития языковой личности педагога и выявить субъективные и средовые факторы, влияющие на полноту самореализации его личностного потенциала в профессиональной деятельности и общении. Методология: используются когнитивно-дискурсивный и синергетический методы. Выводы: Повышение эффективности и качества иноязычного профессионального образования в решающей степени зависит от сформированности триединой основы образовательного процесса: компетентная личность преподавателя – эффективный современный учебник – мотивированный на учебу студент.The aim of the article is to examine the structure and content of the teacher’s language personality development and to identify subjective and environmental factors affecting the completeness of personal potential self-realization in professional activity and communication. Methodology: cognitive-discursive and synergetic methods are used. Conclusions: Improving the efficiency and quality of foreign language professional education depends crucially on the formation of the triune basis of the educational process: a competent teacher's personality – an effective modern textbook - a student motivated to study
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