251 research outputs found
Quasilinear differential equations for the description of the space of ideal gas conditions
Today the classical thermodynamics as fundamentals of many physical sciences does not possess the finished and accurate axiomatic creation of the theory. Its many provisions and ratios are based on the empirical facts which are recognized as apriori and are not proved in terms of theoretical parcel
Investigation of the Earth Ionosphere using the Radio Emission of Pulsars
The investigation of the Earth ionosphere both in a quiet and a disturbed
states is still desirable. Despite recent progress in its modeling and in
estimating the electron concentration along the line of sight by GPS signals,
the impact of the disturbed ionosphere and magnetic field on the wave
propagation still remains not sufficiently understood. This is due to lack of
information on the polarization of GPS signals, and due to poorly conditioned
models of the ionosphere at high altitudes and strong perturbations. In this
article we consider a possibility of using the data of pulsar radio emission,
along with the traditional GPS system data, for the vertical and oblique
sounding of the ionosphere. This approach also allows to monitor parameters of
the propagation medium, such as the dispersion measure and the rotation measure
using changes of the polarization between pulses. By using a selected pulsar
constellation it is possible to increase the number of directions in which
parameters of the ionosphere and the magnetic field can be estimated.Comment: 13 pages, 4 figures, Baltic Astronomy, vol.22, 53-65, 201
An improvement of the Berry--Esseen inequality with applications to Poisson and mixed Poisson random sums
By a modification of the method that was applied in (Korolev and Shevtsova,
2009), here the inequalities
and
are proved for the
uniform distance between the standard normal distribution
function and the distribution function of the normalized sum of an
arbitrary number of independent identically distributed random
variables with zero mean, unit variance and finite third absolute moment
. The first of these inequalities sharpens the best known version of
the classical Berry--Esseen inequality since
by virtue of
the condition , and 0.4785 is the best known upper estimate of the
absolute constant in the classical Berry--Esseen inequality. The second
inequality is applied to lowering the upper estimate of the absolute constant
in the analog of the Berry--Esseen inequality for Poisson random sums to 0.3051
which is strictly less than the least possible value of the absolute constant
in the classical Berry--Esseen inequality. As a corollary, the estimates of the
rate of convergence in limit theorems for compound mixed Poisson distributions
are refined.Comment: 33 page
Ordering of small particles in one-dimensional coherent structures by time-periodic flows
Small particles transported by a fluid medium do not necessarily have to
follow the flow. We show that for a wide class of time-periodic incompressible
flows inertial particles have a tendency to spontaneously align in
one-dimensional dynamic coherent structures. This effect may take place for
particles so small that often they would be expected to behave as passive
tracers and be used in PIV measurement technique. We link the particle tendency
to form one-dimensional structures to the nonlinear phenomenon of phase
locking. We propose that this general mechanism is, in particular, responsible
for the enigmatic formation of the `particle accumulation structures'
discovered experimentally in thermocapillary flows more than a decade ago and
unexplained until now
Quassiclassical approximation of solutions of boundary convective-type problems of heat and mass transfer
In this paper we suggest the approximate method of solving the internal convective heat and mass transfer problems based on the combined use of the Laplace transform and quasiclassical approximatio
ANALYTIC FUNCTIONS OF INFINITE ORDER IN HALF-PLANE
J. B. Meles (1979) considered entire functions with zeros restricted to a finite number of rays. In particular, it was
proved that if is an entire function of infinite order with zeros
restricted to a finite number of rays, then its lower order equals
infinity. In this paper, we prove a similar result for a class of functions analytic in the upper half-plane. The analytic function in
C+ = { : Im > 0} is called proper analytic if lim sup(z→t)( ln|f(z)|)≤0
for all real numbers ∈ R. The class of the proper analytic functions is denoted by . The full measure of a function ∈ is
a positive measure, which justifies the term "proper analytic function". In this paper, we prove that if a function is the proper
analytic function in the half-plane C+ of infinite order with zeros
restricted to a finite number of rays L through the origin, then its
lower order equals infinity
The JEREMI-project on thermocapillary convection in liquid bridges. Part B : Overview on impact of co-axial gas flow
Pure surface-tension-driven flow is a unique type of flow that can be controlled through external manipulation of thermal and/or mechanical boundary conditions at the free liquid surface where the entire driving force for the convection is generated. This unique feature has been exploited in recent studies for the active control of the flow instability. The use of forced coaxial gas streams has been proposed as a way to stabilize the Marangoni convection in liquid bridges in the planned space experiment JEREMI (Japanese and European Research Experiment on Marangoni Instabilities). It is aimed at understanding the mechanism of the instability and the role of the surface heat transfer and surface shear stresses. This overview presents corresponding preparatory experimental and numerical studies
The JEREMI-project on thermocapillary convection in liquid bridges. Part A : Overview of particle accumulation structures
The rapid accumulation of particles suspended in a thermocapillary liquid bridge is planned to be investigated during the JEREMI experiment on the International Space Station scheduled for 2016. An overview is given of the current status of experimental and numerical investigations of this phenomenon
ТРАНСДИСЦИПЛІНАРНЕ ПРЕДСТАВЛЕННЯ ІНФОРМАЦІЇ ЗА ДОПОМОГОЮ ІНТЕРАКТИВНИХ ДОКУМЕНТІВ
Theoretical generalizations and possibilities of practical use of ontology of knowledge in public health, in particular in diagnosis and choice of a method of treatment for diseases of the gastrointestinal tract in children, are investigated. It is shown that the consequence of the existence of a homomorphism between the primary structure of the text and the structure of information from it highlights the possibility of constructing a specialized structure designed to work not with ontology objects but with lexemes of the primary structure. The interactive document (Tsn,NS') built on its basis can be used to form an arbitrary network information system in the object plane.Исследованы теоретические обобщения и возможности практического использования онтологии знаний в здравоохранении, в частности в диагностике и выборе метода лечения при заболеваниях желудочно-кишечного тракта у детей. Показано, что следствием существования гомоморфизма между первичной структурой текста и структурой информации из него выделяется возможность построения специализированной структуры, предназначенной для работы не с объектами онтологии, а лексемами первичной структуры. Построенный на ее основе интерактивный документ (Tsn,NS') может использоваться для формирования произвольной сетевой информационной системы в предметной плоскости.Досліджено теоретичні узагальнення та можливості практичного використання онтології знань в охороні здоров'я, зокрема в діагностиці та виборі методу лікування при захворюваннях шлунково-кишкового тракту в дітей. Показано, що наслідком існування гомоморфізму між первинною структурою тексту та структурою інформації, що з нього виділяється, є можливість побудови спеціалізованої структури, призначеної для роботи не з об'єктами онтології, а лексемами первинної структури. Побудований на її основі інтерактивний документ (Tsn,NS') може використовуватися для формування довільної мережевої інформаційної системи в предметній площині
Digital receivers for low-frequency radio telescopes UTR-2, URAN, GURT
This paper describes digital radio astronomical receivers used for decameter
and meter wavelength observations. This paper describes digital radio
astronomical receivers used for decameter and meter wavelength observations.
Since 1998, digital receivers performing on-the-fly dynamic spectrum
calculations or waveform data recording without data loss have been used at the
UTR-2 radio telescope, the URAN VLBI system, and the GURT new generation radio
telescope. Here we detail these receivers developed for operation in the strong
interference environment that prevails in the decameter wavelength range. Data
collected with these receivers allowed us to discover numerous radio
astronomical objects and phenomena at low frequencies, a summary of which is
also presented.Comment: 24 pages, 15 figure
- …