416 research outputs found

    Integrable boundary conditions for classical sine-Gordon theory

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    The possible boundary conditions consistent with the integrability of the classical sine-Gordon equation are studied. A boundary value problem on the half-line x≤0x\leq 0 with local boundary condition at the origin is considered. The most general form of this boundary condition is found such that the problem be integrable. For the resulting system an infinite number of involutive integrals of motion exist. These integrals are calculated and one is identified as the Hamiltonian. The results found agree with some recent work of Ghoshal and Zamolodchikov.Comment: 10 pages, DTP/94-3

    Application of data mining technology to optimize the city transport network

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    © 2016 IEEE. The article considers the experience of OLAP-technology in solving optimization problems of the city transport system. The authors proposed a conceptual decision support scheme to optimize the transport-road network parameters. The developed system provides the possibility of intelligent analysis and decision-making based on OLAP-technologies and simulation models

    X-ray line formation in the spectrum of SS 433

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    The mechanisms for the formation of X-ray lines in the spectrum of SS 433 are investigated by taking into account the radiative transfer inside the jets. The results of Monte Carlo numerical simulations are presented. The effect of a decrease in line intensity due to scattering inside the jet turns out to be pronounced, but it does not exceed 60% in magnitude on the entire grid of parameters. The line broadening due to scattering, nutational motion, and the contribution of satellites can lead to overestimates of the jet opening angle Θ\Theta from the line widths in Chandra X-ray observations. The fine structure of the lines turns out to be very sensitive to the scattering effects. This makes its investigation by planned X-ray observatories equipped with high-resolution spectrometers (primarily Astro-H) a powerful tool for diagnosing the parameters of the jets in SS 433.Comment: 23 pages, 14 figures, to be published in Astronomy Letters, v. 38, n. 7, p. 443 (2012

    Transition to «green» economy in Russia: Current and long-term challenges

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    Nowadays, many believe that there is no way to ecological stability other than transition to «environmentally oriented economy». In urban areas, the main sources of pollutants are industrial enterprises and automobile transport. To reduce the adverse environmental impacts one needs special methods of air quality control. Specifically, research in this field is aimed at developing of control systems for the city transport in order to predict the environmental response to changing traffic parameters and take appropriate measures to improve the situation. In this work it is demonstrated how the method of transport system control, based on simulation modeling, has been implemented. The optimization experiment has been performed on a simulation model adjusting the parameters of parts of a city road network for adequate decision making. Model experimenting has made it possible to establish the optimal traffic density and average current rates, without exceeding the pollution quotas, and calculate the consequences of changing in the number of vehicle car fleet on city roads. The experiment was carried out in the city of Naberezhnye Chelny, Russia

    Modeling of traffic flows with due regard to ecological criteria

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    The article deals with issues of ensuring the reliable and safe city transport system operation through the use of the rational management methods. To make evidence-based management decisions are encouraged to use worked out intelligent decision support system. It is shown that a comprehensive solution of the city transport system management contributes to the sustainable development of the region

    Yang-Baxter algebra and generation of quantum integrable models

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    An operator deformed quantum algebra is discovered exploiting the quantum Yang-Baxter equation with trigonometric R-matrix. This novel Hopf algebra along with its q→1q \to 1 limit appear to be the most general Yang-Baxter algebra underlying quantum integrable systems. Three different directions of application of this algebra in integrable systems depending on different sets of values of deforming operators are identified. Fixed values on the whole lattice yield subalgebras linked to standard quantum integrable models, while the associated Lax operators generate and classify them in an unified way. Variable values construct a new series of quantum integrable inhomogeneous models. Fixed but different values at different lattice sites can produce a novel class of integrable hybrid models including integrable matter-radiation models and quantum field models with defects, in particular, a new quantum integrable sine-Gordon model with defect.Comment: 13 pages, revised and bit expanded with additional explanations, accepted for publication in Theor. Math. Phy

    Properties of the Line-of-Sight Velocity Field in the Hot and X-ray Emitting Circumgalactic Medium of Nearby Simulated Disk Galaxies

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    The hot, X-ray-emitting phase of the circumgalactic medium in galaxies is believed to be the reservoir of baryons from which gas flows onto the central galaxy and into which feedback from AGN and stars inject mass, momentum, energy, and metals. These effects shape the velocity fields of the hot gas, which can be observed by X-ray IFUs via the Doppler shifting and broadening of emission lines. In this work, we analyze the gas kinematics of the hot circumgalactic medium of Milky Way-mass disk galaxies from the TNG50 simulation with synthetic observations to determine how future instruments can probe this velocity structure. We find that the hot phase is often characterized by outflows outward from the disk driven by feedback processes, radial inflows near the galactic plane, and rotation, though in other cases the velocity field is more disorganized and turbulent. With a spectral resolution of ∼\sim1 eV, fast and hot outflows (∼\sim200-500 km s−1^{-1}) can be measured, depending on the orientation of the galaxy on the sky. The rotation velocity of the hot phase (∼\sim100-200 km s−1^{-1}) can be measured using line shifts in edge-on galaxies, and is slower than that of colder gas phases but similar to stellar rotation velocities. By contrast, the slow inflows (∼\sim50-100 km s−1^{-1}) are difficult to measure in projection with these other components. We find that the velocity measured is sensitive to which emission lines are used. Measuring these flows will help constrain theories of how the gas in these galaxies forms and evolves.Comment: 41 pages, 29 figures, submitted to Ap
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