Gibbs attractor: a chaotic nearly Hamiltonian system, driven by external harmonic force

A chaotic autonomous Hamiltonian systems, perturbed by small damping and small external force, harmonically dependent on time, can acquire a strange attractor with properties similar to that of the canonical distribution - the Gibbs attractor. The evolution of the energy in such systems can be described as the energy diffusion. For the nonlinear Pullen - Edmonds oscillator with two degrees of freedom the properties of the Gibbs attractor and their dependence on parameters of the perturbation are studied both analytically and numerically.Comment: 8 pages RevTeX, 3 figure

The evolution of electron dispersion in the series of rare-earth tritelluride compounds obtained from their charge-density-wave properties and susceptibility calculations

We calculated electron susceptibility of rare-earth tritelluride compounds RTe$_3$ as a function of temperature, wave vector and electron-dispersion parameters. Comparison of results obtained with the available experimental data on the transition temperature and on the wave vector of a charge-density wave in these compounds allowed us to predict values and the evolution of electron-dispersion parameters with the variation of atomic number of rare-earth element R.Comment: 6 pages, 6 figure

A Modified Version of the Waxman Algorithm

The iterative algorithm recently proposed by Waxman for solving eigenvalue problems, which relies on the method of moments, has been modified to improve its convergence considerably without sacrificing its benefits or elegance. The suggested modification is based on methods to calculate low-lying eigenpairs of large bounded hermitian operators or matrices

ОГРАНИЧЕНИЯ ПО ИСПОЛЬЗОВАНИЮ МАТРИЦЫ ИКАО ПРИ ОЦЕНКЕ РИСКОВ ДЛЯ БЕЗОПАСНОСТИ ПОЛЕТОВ

The article analyzes the benefits and drawbacks of the matrix of consequences and probability (ICAO risk matrix) as a method of safety risk assessment. The ICAO matrix is a qualitative method of risk management based on expert assessments of the degree of probability of individual possible events and of their consequences. The method is simple and easy to use, but can only assess separate differential risks.The article shows the failure of using the ICAO matrix for quantitative risk assessment of «past events» and deviations in the operational activity of the airline and getting an integrated risk of the airline and its monitoring.The article also describes the limitations of this method in solving the tasks of corrective measures prioritization in case of negative correlation between the probability and severity of consequences of events. В статье анализируются возможности и недостатки матрицы последствий и вероятностей (матрицы рисков ИКАО) как метода оценки рисков для безопасности полетов.Матрица ИКАО является качественным методом управления риском, основанным на экспертных оценках степени вероятности отдельных возможных событий и потенциальной опасности их последствий. Метод являетсяпростым и удобным в использовании, но позволяет оценивать только отдельные дифференциальные риски.В статье на конкретных примерах показана несостоятельность попыток использования матрицы ИКАО дляколичественных оценок риска «прошлых событий» и отклонений в эксплуатационной деятельности авиапредприятия, получения интегрального риска авиапредприятия и его мониторинга. Также показана ограниченность данногометода в части решения задач приоритизации корректирующих мероприятий при отрицательной корреляции степени вероятности и серьезности последствий событий

USING COGNITIVE GRAPHICS ACCEPTANCE AT DATA MINING DATABASES OF INDUSTRIAL CONTROL IN METALLURGY

В данной исследовательской работе были сопоставлены возможности различных приёмов когнитивной графики для контроля процесса и продукта в черной металлургии с целью управления качеством продукции без изменения технологии по существу. Использование предложенных подходов показало высокую эффективность для поиска существенных закономерностей в системе «управляющие параметры – свойства».In this research work have been compared the possibilities of different methods of cognitive graphics for process control and product in the steel industry for the purpose of quality control of production without substantive changes of technology. Using the proposed approach has shown high efficiency to find significant of regularities in the system of "control parameters - property"

Spallative ablation of dielectrics by X-ray laser

Short laser pulse in wide range of wavelengths, from infrared to X-ray, disturbs electron-ion equilibrium and rises pressure in a heated layer. The case where pulse duration $\tau_L$ is shorter than acoustic relaxation time $t_s$ is considered in the paper. It is shown that this short pulse may cause thermomechanical phenomena such as spallative ablation regardless to wavelength. While the physics of electron-ion relaxation on wavelength and various electron spectra of substances: there are spectra with an energy gap in semiconductors and dielectrics opposed to gapless continuous spectra in metals. The paper describes entire sequence of thermomechanical processes from expansion, nucleation, foaming, and nanostructuring to spallation with particular attention to spallation by X-ray pulse

Minimal half-spaces and external representation of tropical polyhedra

We give a characterization of the minimal tropical half-spaces containing a given tropical polyhedron, from which we derive a counter example showing that the number of such minimal half-spaces can be infinite, contradicting some statements which appeared in the tropical literature, and disproving a conjecture of F. Block and J. Yu. We also establish an analogue of the Minkowski-Weyl theorem, showing that a tropical polyhedron can be equivalently represented internally (in terms of extreme points and rays) or externally (in terms of half-spaces containing it). A canonical external representation of a polyhedron turns out to be provided by the extreme elements of its tropical polar. We characterize these extreme elements, showing in particular that they are determined by support vectors.Comment: 19 pages, 4 figures, example added with a new figure, figures improved, references update

Search for a dark vector gauge boson decaying to π+π−\pi^+ \pi^- using η→π+π−γ\eta \rightarrow \pi^+\pi^- \gamma decays

We report a search for a dark vector gauge boson $U^\prime$ that couples to quarks in the decay chain $D^{*+} \to D^0 \pi^+, D^0 \to K^0_S \eta, \eta \to U^\prime \gamma$, $U^\prime \to \pi^+ \pi^-$. No signal is found and we set a mass-dependent limit on the baryonic fine structure constant of $10^{-3} - 10^{-2}$ in the $U^\prime$ mass range of 290 to 520 MeV/$c^2$. This analysis is based on a data sample of 976 fb$^{-1}$ collected by the Belle experiment at the KEKB asymmetric-energy $e^+e^-$ collider.Comment: 6 pages, 4 figure