1,062 research outputs found
Новый вид жуков малашек рода Kuatunia Evers, 1949 (Coleoptera: Cleroidea, Malachiidae) из Непала
A new malachiid beetle species Kuatunia andreasi Tshernyshev, sp.n. is described from Nepal (Karnali Province). Figures of the external appearance, elytral apices, and genitalia of the male are provided for the new species. A key to all species of the genus Kuatunia Evers, 1949 is given
Limit theorems for random point measures generated by cooperative sequential adsorption
We consider a finite sequence of random points in a finite domain of a
finite-dimensional Euclidean space. The points are sequentially allocated in
the domain according to a model of cooperative sequential adsorption. The main
peculiarity of the model is that the probability distribution of a point
depends on previously allocated points. We assume that the dependence vanishes
as the concentration of points tends to infinity. Under this assumption the law
of large numbers, the central limit theorem and Poisson approximation are
proved for the generated sequence of random point measures.Comment: 17 page
Mathematical simulation of a profile cutter as a surface of revolution
Various types of cutters (spherical, toroidal, etc.) are used in surface processing of parts of a transmission mechanism. The cost of a special profile tool is somewhat higher than that of such cutters. But the increase in the cost of the tool is compensated by a significant reduction in the time of processing parts. The present paper deals with a mathematical model of a profile cutter surface (as a surface of revolution) for processing parts of a cylindrical transmission gear with an eccentrically cycloidal gearing (EC-gearing). A computer program for determining radii of the cutter's circular cross sections for a given set of axial displacements was created
Threshold Resonant Structure of the 232Th Neutron-Induced Fission Cross Section
The structures observed in the sub-threshold neutron-induced fission of
^{232}Th were investigated employing a recent developed model. Theoretical
single-particle excitations of a phenomenological two-humped barrier are
determined by solving a system of coupled differential equations for the motion
along the optimal fission path. A rather good agreement with experimental data
was obtained using a small number of independent parameters. It is predicted
that the structure at 1.4 and 1.6 MeV is mainly dominated by spin 3/2 partial
cross-section with small admixture of spin 1/2, while the structure at 1.7 MeV
is given by a large partial cross section of spin 5/2.Comment: 17 pages 11 figure
Dispersion of Waves in Relativistic Plasmas with Isotropic Particle Distributions
The dispersion laws of Langmuir and transverse waves are calculated in the
relativistic non-magnetized formalism for several isotropic particle
distributions: thermal, power-law, relativistic Lorentzian and hybrid
. For Langmuir waves the parameters of superluminal undamped, subluminal
damped principal and higher modes are determined for a range of distribution
parameters. The undamped and principal damped modes are found to match
smoothly. Principal damped and second damped modes are found not to match
smoothly. The presence of maximum wavenumber is discovered above that no
longitudinal modes formally exist. The higher damped modes are discovered to be
qualitatively different for thermal and certain non-thermal distributions.
Consistently with the known results, the Landau damping is calculated to be
stronger for non-thermal power-law-like distributions. The dispersion law is
obtained for the single undamped transverse mode. The analytic results for the
simplest distributions are provided.Comment: 8 pages, 12 figures, accepted by Physics of Plasma
Almost Periodic and Asymptotically Almost Periodic Solutions of Liénard Equations
The aim of this paper is to study the almost periodic and asymptotically almost periodic solutions on (0,+1) of the Li´enard equation
x′′ + f(x)x′ + g(x) = F(t),
where F : T ! R (T = R+ or R) is an almost periodic or asymptotically almost periodic function and g : (a, b) ! R is a strictly decreasing function. We study also this problem for the vectorial Li´enard equation.
We analyze this problem in the framework of general non-autonomous dynamical systems (cocycles). We apply the general results obtained in our early papers [3, 7] to prove the existence of almost periodic (almost automorphic, recurrent, pseudo recurrent) and asymptotically almost periodic (asymptotically almost automorphic, asymptotically recurrent, asymptotically pseudo
recurrent) solutions of Li´enard equations (both scalar and vectorial)
The mathematical model of the chevron-arch gearing transmitter
The teeth of herringbone transmission wheels are obtained by docking two helical wheels with an opposite arrangement of teeth, which can solve the problem of the axial force. The mathematical model of coupling chevron teeth of the driving wheel in the area of their docking using the arch tooth fragment is developed. The conjugacy area surface of the driven wheel chevron teeth is obtained as the envelope of the surfaces family formed by the arched tooth during the process of the parts motion
Bionic models for identification of biological systems
This article proposes a clinical decision support system that processes biomedical data. For this purpose a bionic model has been designed based on neural networks, genetic algorithms and immune systems. The developed system has been tested on data from pregnant women. The paper focuses on the approach to enable selection of control actions that can minimize the risk of adverse outcome. The control actions (hyperparameters of a new type) are further used as an additional input signal. Its values are defined by a hyperparameter optimization method. A software developed with Python is briefly described
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