On the Length of the Relaxation Zone of Ionization Behind a Strong Shock Wave Front in the Air

Relaxation zone behind strong shock wave front in ai

ВСМ: ИНТЕЛЛЕКТУАЛЬНЫЙ ПОДХОД

The theoretical basis of application of methods of artificial intelligence (expert systems, artificial neural networks, genetic algorithms) to organizational and technological decisions in construction of high-speed rail is provided in the article. The author describes an efficient method for implementation of such decisions with the use of information model and system of management decisions on the results of the monitoring of the construction process.Представлены теоретические основы применения методов искусственного интеллекта (экспертных систем, искусственных нейронных сетей, генетических алгоритмов) к разработке организационно-технологических решений в строительстве высокоскоростных магистралей (ВСМ). Описан вариант эффективной реализации подобной методики с использованием информационной модели и системы подготовки управленческих решений по результатам мониторинга строительного процесса

Monoenergetic proton beams accelerated by a radiation pressure driven shock

High energy ion beams (> MeV) generated by intense laser pulses promise to be viable alternatives to conventional ion beam sources due to their unique properties such as high charge, low emittance, compactness and ease of beam delivery. Typically the acceleration is due to the rapid expansion of a laser heated solid foil, but this usually leads to ion beams with large energy spread. Until now, control of the energy spread has only been achieved at the expense of reduced charge and increased complexity. Radiation pressure acceleration (RPA) provides an alternative route to producing laser-driven monoenergetic ion beams. In this paper, we show the interaction of an intense infrared laser with a gaseous hydrogen target can produce proton spectra of small energy spread (~ 4%), and low background. The scaling of proton energy with the ratio of intensity over density (I/n) indicates that the acceleration is due to the shock generated by radiation-pressure driven hole-boring of the critical surface. These are the first high contrast mononenergetic beams that have been theorised from RPA, and makes them highly desirable for numerous ion beam applications

Metallurgical hydrogen as an indicator and cause of damage of rolled steel

Fatigue tests and measurements of the volumetric distribution of metallurgical hydrogen in specimens cut from rolled I-beam 60Sh3 made of steel 10KhSND were carried out. Fatigue tests show a 20% reduction in fatigue limits compared to similar sheet material. On the fractures of the samples, there are flock-like defects in the areas of interface of the flanges of the I-beam or in the so-called zones of difficult deformation. The concentration of metallurgical hydrogen is unevenly distributed and varies from 0.17 ppm to 1.8 ppm. Large concentrations of hydrogen are observed in the zones of difficult deformation, which indicates the hydrogen nature of the metal defects observed at the fracture. The result of mechanical tests and hydrogen diagnostics is a manufacturing defect of rolled products that cannot be corrected. Hydrogen diagnostics using metallurgical hydrogen (without hydrogen charging samples) requires essentially less time than mechanical tests and yields the adequate result

Almost Perfect Privacy for Additive Gaussian Privacy Filters

We study the maximal mutual information about a random variable $Y$ (representing non-private information) displayed through an additive Gaussian channel when guaranteeing that only $\epsilon$ bits of information is leaked about a random variable $X$ (representing private information) that is correlated with $Y$. Denoting this quantity by $g_\epsilon(X,Y)$, we show that for perfect privacy, i.e., $\epsilon=0$, one has $g_0(X,Y)=0$ for any pair of absolutely continuous random variables $(X,Y)$ and then derive a second-order approximation for $g_\epsilon(X,Y)$ for small $\epsilon$. This approximation is shown to be related to the strong data processing inequality for mutual information under suitable conditions on the joint distribution $P_{XY}$. Next, motivated by an operational interpretation of data privacy, we formulate the privacy-utility tradeoff in the same setup using estimation-theoretic quantities and obtain explicit bounds for this tradeoff when $\epsilon$ is sufficiently small using the approximation formula derived for $g_\epsilon(X,Y)$.Comment: 20 pages. To appear in Springer-Verla

Application of dynamic priorities for controlling the characteristics of a queuing system

This paper considers the development and modification of an imitation model of a queuing system. The initial model uses the laws of control (discipline of expectation and service) with mixed priorities. The work investigates the model with three types of entities (absolute priority, relative priority and priority-free ones) in the regime of overload, i.e. a system with losses. Verification and validation of the created imitation model confirmed its adequateness and accuracy of received results. The application of dynamic priorities for changing the laws of model control substantially alters certain system characteristics. The creation of the model in MatLab Simulink environment with the use of SimEvents and Stateflow library modules allowed creating a fairly complex queuing system and obtain new interesting results

Kaon pair production in proton-nucleus collisions at 2.83 GeV kinetic energy

The production of non-phi K+K- pairs by protons of 2.83 GeV kinetic energy on C, Cu, Ag, and Au targets has been investigated using the COSY-ANKE magnetic spectrometer. The K- momentum dependence of the differential cross section has been measured at small angles over the 0.2--0.9 GeV/c range. The comparison of the data with detailed model calculations indicates an attractive K- -nucleus potential of about -60 MeV at normal nuclear matter density at a mean momentum of 0.5 GeV/c. However, this approach has difficulty in reproducing the smallness of the observed cross sections at low K- momenta.Comment: 7 pages, 5 figures, 1 tabl

Gastrointestinal stromal tumors in elderly patients

To study the age-related characteristics of GISTs development in patients of older age group