818 research outputs found
Using parallel computing in modeling and optimization of mineral reserves extraction systems
Annotation This article describes algorithm for solving ultimate pit limit problem (UPIT), or a maximum weight closure problem. There are several method for solving this problem. We provide new approach, for solving ultimate pit limit problem using precedence model. Block model of open pit can be easily represented as an oriented graph. Then to solve ultimate pit limit problem it is required to find such a sub graph in a graph whose sum of weights will be maximal. One of the possible solutions of this problem is using genetic algorithms. We use a parallel genetic algorithm for accelerating of computational process. In this version of algorithm fitness function of each individual calculating in different thread. It allows reducing running time of algorithm. Details of implementation parallel genetic algorithm for searching open pit limits are provided. Comparison with other methods and results of computational experiments provided.Keywords: open pit limits, genetics algorithms, high-performance computin
Интегрирование быстро осциллирующих функций
The paper demonstrates approximate methods of integral calculation of highly oscillatory functions. The paper describes a quadrature method which adopts Chebyshev differential matrix to solve the ordinary differential equation (ODE) and thus obtain integral values. This method make the system of linear equations well-conditioned for general oscillatory integrals. Furthermore, even if the system of linear equations is ill-conditioned, regularization method can be adopted to solve it properly and eventually obtain accurate integral results.Умение вычислять интегралы от быстро осциллирующих функций является принципиально важным для решения многих задач оптики, электродинамики, квантовой механики, ядерной физики и многих других областях. В статье рассматривается метод приближенного вычисления интегралов от быстро осциллирующих функций с помощью перехода к численному решению системы обыкновенных дифференциальных уравнений. Использование чебышевской дифференциальной матрицы позволяет далее свести задачу к решению системы линейных алгебраических уравнений, чаще всего невырожденной. Однако и в случае плохой обусловленности системы линейных алгебраических уравнений применение метода тихоновской регуляризации позволяет с высокой точностью получать искомые значения интегралов
Using ion beams for creation of nanostructures on the surface of high-stable materials
Main ion-beam etching techniques for creation of nanostructures on the
surface of high-stable materials have been considered. Methods of information recording
in the form of nanostructure on the metallic substrate surface have been analyzed.
Application of glass substrate for creation long-term data carrier was proposed.
Microrelief information record on the glass substrate surface was obtained using the ionbeam
etching
Electric dipole moments of Hg, Xe, Rn, Ra, Pu, and TlF induced by the nuclear Schiff moment and limits on time-reversal violating interactions
We have calculated the atomic electric dipole moments (EDMs) induced in
^{199}Hg, ^{129}Xe, ^{223}Rn, ^{225}Ra, and ^{239}Pu by their respective
nuclear Schiff moments S. The results are (in units 10^{-17}S(e {fm}^{3})^{-1}e
cm): d(^{199}Hg)=-2.8, d(^{129}Xe)=0.38, d(^{223}Rn)=3.3, d(^{225}Ra)=-8.5,
d(^{239}Pu)=-11. We have also calculated corrections to the parity- and
time-invariance-violating (P,T-odd) spin-axis interaction constant in TlF.
These results are important for the interpretation of atomic and molecular
experiments on EDMs in terms of fundamental P,T-odd parameters.Comment: 16 page
Выделение перспективных площадей и их оценка на основе уникального комплекса методов
In today's world the search for gold deposits are very relevant. The article shows a unique method of allocation prospective gold mineralization areas, basing on paleovolcanic reconstructions, and its estimation by iodometric and lithogeochemical studies.В статье рассмотрена уникальная методика выделения перспективных на выявление золоторудной минерализации площадей на основе палеовулканических реконструкций; дана их оценка с помощью литогеохимических и йодометрических исследований
Analysis of properties of optical carriers after long-term storage
Performed in this paper is the analysis of possibilities to create optical
information carriers for long-term information storage. Adduced are the results of
experimental investigations of properties inherent to optical carriers of the WORM type
after 25-year storage. It has been shown that their micro-relief structure formed by using
focused laser radiation on thin films of chalcogenide vitreous semiconductors had not
been practically changed after storing them for the above mentioned period in non-heated
areas
Where are the missing members of the baryon antidecuplet?
We analyze what consequences has the observation of exotic pentaquark baryons
on the location of the non-exotic baryons belonging to the antidecuplet. We
suggest that there must be a new nucleon state at 1650-1690 MeV and a new Sigma
baryon at 1760-1810 MeV.Comment: 5 pages, 1 figure. Missing reference adde
Testing +/- 1-Weight Halfspaces
We consider the problem of testing whether a Boolean function f:{ − 1,1} [superscript n] →{ − 1,1} is a ±1-weight halfspace, i.e. a function of the form f(x) = sgn(w [subscript 1] x [subscript 1] + w [subscript 2] x [subscript 2 ]+ ⋯ + w [subscript n] x [subscript n] ) where the weights w i take values in { − 1,1}. We show that the complexity of this problem is markedly different from the problem of testing whether f is a general halfspace with arbitrary weights. While the latter can be done with a number of queries that is independent of n [7], to distinguish whether f is a ±-weight halfspace versus ε-far from all such halfspaces we prove that nonadaptive algorithms must make Ω(logn) queries. We complement this lower bound with a sublinear upper bound showing that poly queries suffice
The accuracy of merging approximation in generalized St. Petersburg games
Merging asymptotic expansions of arbitrary length are established for the
distribution functions and for the probabilities of suitably centered and
normalized cumulative winnings in a full sequence of generalized St. Petersburg
games, extending the short expansions due to Cs\"org\H{o}, S., Merging
asymptotic expansions in generalized St. Petersburg games, \textit{Acta Sci.
Math. (Szeged)} \textbf{73} 297--331, 2007. These expansions are given in terms
of suitably chosen members from the classes of subsequential semistable
infinitely divisible asymptotic distribution functions and certain derivatives
of these functions. The length of the expansion depends upon the tail
parameter. Both uniform and nonuniform bounds are presented.Comment: 30 pages long version (to appear in Journal of Theoretical
Probability); some corrected typo
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