346 research outputs found
Inverse problems of symbolic dynamics
This paper reviews some results regarding symbolic dynamics, correspondence
between languages of dynamical systems and combinatorics. Sturmian sequences
provide a pattern for investigation of one-dimensional systems, in particular
interval exchange transformation. Rauzy graphs language can express many
important combinatorial and some dynamical properties. In this case
combinatorial properties are considered as being generated by substitutional
system, and dynamical properties are considered as criteria of superword being
generated by interval exchange transformation. As a consequence, one can get a
morphic word appearing in interval exchange transformation such that
frequencies of letters are algebraic numbers of an arbitrary degree.
Concerning multydimensional systems, our main result is the following. Let
P(n) be a polynomial, having an irrational coefficient of the highest degree. A
word (w=(w_n), n\in \nit) consists of a sequence of first binary numbers
of i.e. . Denote the number of different subwords
of of length by .
\medskip {\bf Theorem.} {\it There exists a polynomial , depending only
on the power of the polynomial , such that for sufficiently
great .
Explosive Materials Combustion by Heated Wires
The knowledge of ignition parameters of explosive materials (EM) presents both the definite scientific interest for developing the ignition kinetics models and the practical interest from the point of view of their danger assessment. The present investigations, as opposed to the known technique for EMs ignition temperature determination, have been performed by using the model explosive material samples of high density which have been produced on the basis of HMX and TATB. Applying the technique of firing ballistic powders by a heated wire, the EM ignition temperature depending on the time (rate) of heating has been investigated. The technique makes it possible to calculate heat pulses and heat flows leading to ignition. By decreasing the heat flow, the time for the EM heating up to ignition increases and temperature falls thereby approaching the critical value, characterising the danger limit under accidents associated with heating. The ignition of EM based on HMX and TATB takes place in a different manner. With the EM on the basis of HMX and with great heat flows. The ignition beginning from the surface in the form of flash is typical but when achieving the critical parameters, the heated layer flash takes place that increases the probability of the explosion realisation. EM based on TATH always ignite in the form of combustion from the surface, independent of the heat flow that points to the higher extent of its safety. These data correlate well with the higher parameters of its ignition
The level of somatic health, sports specialization and qualification of an athlete as indicators of intermediate selection in the mixed martial arts
This article presents the results of experimental research to identify high-priority types of martial arts whose representatives successfully implement their skills in mixed martial arts, as well as the results of the study of somatic healt
The importance of secondary school students' physical activity in modern environment
The research was aimed at evaluating physical activity of students, who live in the city and rural areas, identifying the relationship between physical activity and school performance, as well as studying the dependence of the number of diseases on the volume of locomotion. To this end, in the Belgorod Oblast, 1,488 schoolchildren of 5-11 grades were surveyed from 2014 to 201
The Beginning of the Path: the Strategy of Poetic Self-Determination in the Early Poetry of Olga Skopichenko, Maria Vizi and Elena Grot
The article deals with the problem of formation of poetic self-determination in early works of the Russian émigré poetesses M. Vizi, E. Grot, O. Skopichenko. They belong to two branches of the Russian émigré literature of the first wave: eastern and western (American). They left early enough Russia and moved to the Far East, where M. Vizi and O. Skopichenko published their first collections of poems. Later all three poetesses settled in San-Francisco and they were among the organizers and members of the Literary-Art Circle/В статье рассматривается проблема формирования поэтического самоопределения в раннем творчестве поэтесс русской эмиграции М. Визи, Е. Грот и О. Скопиченко
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