1,326 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
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
Application of approximation theory by nonlinear manifolds in Sturm-Liouville inverse problems
We give here some negative results in Sturm-Liouville inverse theory, meaning
that we cannot approach any of the potentials with integrable derivatives
on by an -parametric analytic family better than order
of .
Next, we prove an estimation of the eigenvalues and characteristic values of
a Sturm-Liouville operator and some properties of the solution of a certain
integral equation. This allows us to deduce from [Henkin-Novikova] some
positive results about the best reconstruction formula by giving an almost
optimal formula of order of .Comment: 40 page
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
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
Stability of the inverse resonance problem on the line
In the absence of a half-bound state, a compactly supported potential of a
Schr\"odinger operator on the line is determined up to a translation by the
zeros and poles of the meropmorphically continued left (or right) reflection
coefficient. The poles are the eigenvalues and resonances, while the zeros also
are physically relevant. We prove that all compactly supported potentials
(without half-bound states) that have reflection coefficients whose zeros and
poles are \eps-close in some disk centered at the origin are also close (in a
suitable sense). In addition, we prove stability of small perturbations of the
zero potential (which has a half-bound state) from only the eigenvalues and
resonances of the perturbation.Comment: 21 page
Reconstruction of the optical potential from scattering data
We propose a method for reconstruction of the optical potential from
scattering data. The algorithm is a two-step procedure. In the first step the
real part of the potential is determined analytically via solution of the
Marchenko equation. At this point we use a diagonal Pad\'{e} approximant of the
corresponding unitary -matrix. In the second step the imaginary part of the
potential is determined via the phase equation of the variable phase approach.
We assume that the real and the imaginary parts of the optical potential are
proportional. We use the phase equation to calculate the proportionality
coefficient. A numerical algorithm is developed for a single and for coupled
partial waves. The developed procedure is applied to analysis of
, , and data.Comment: 26 pages, 8 figures, results of nucl-th/0410092 are refined, some new
results are presente
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