The results of modeling the effects of stochastic levels of sound speed on formation of the zonal structure of acoustic fields for the hydrologic and acoustic environment of the deep part of the Sea ...of Japan. Numerical experiment involved calculation of the vertical structure of acoustic fields at the ranges from 20 to 120 km with discontinuity equal to 50 m in beam zooming for the set values of random component of sound speed field. In accordance with calculation, analytical correlations of changing coordinates of the closest and the furthest borderlines of the first three convergence zones at emitter depth depending on the level of random component of sound speed field were determined. Changes in borderlines of convergence zones occur in accordance with linear law; this said, the closest borderlines shift towards the emitter and the furthest borderlines - away from it. The obtained results of analyzing changes in structure of vertical distribution of acoustic field at the borderlines of convergence zones can be applied for engineering the systems of underwater monitoring for detection of local disruptions of acoustic velocity field of various nature against natural stochastic parameters of water environment in the deep part of the Sea of Japan.
An integrated method for optimization of a welded portion of a high pressure compressor rotor as a single object is developed. The minimum mass criterion is used in the optimization method; ...limitations are imposed in accordance with strength and stiffness requirements. An example is given of optimization of a typical welded portion of a high pressure compressor rotor resulting in mass reduction and increase of cyclic durability.
Dark sectors charged under a new Abelian interaction have recently received much attention in the context of dark matter models. These models introduce a light new mediator, the so-called dark photon ...(A^{'}), connecting the dark sector to the standard model. We present a search for a dark photon in the reaction e^{+}e^{-}→γA^{'}, A^{'}→e^{+}e^{-}, μ^{+}μ^{-} using 514 fb^{-1} of data collected with the BABAR detector. We observe no statistically significant deviations from the standard model predictions, and we set 90% confidence level upper limits on the mixing strength between the photon and dark photon at the level of 10^{-4}-10^{-3} for dark photon masses in the range 0.02-10.2 GeV. We further constrain the range of the parameter space favored by interpretations of the discrepancy between the calculated and measured anomalous magnetic moment of the muon.
The paper presents the results of modeling the pricing mechanism in the residential real estate market (by using Moscow as an example). The key factors that influence the monthly and annual dynamics ...of real estate prices are revealed; their quantitative impact is assessed using regression analysis methods. The close dependence of the real estate price on the change in the US dollar-ruble exchange rate in a monthly model with a distributed lag is revealed. In the annual model, the best explanatory force is possessed by factors such as the dynamics of the Urals oil prices and the change in the average cost of basic materials, parts, and structures purchased by construction companies in the current year. The study also proposes a new indicator, which, is believed by the authors to approximate the change in the propensity to save in high-income groups of the population.
The results of experimental studies and numerical simulation of the fragmentation of aluminum alloy projectiles on a tungsten mesh bumper at impact velocities of up to 7 km/s are presented. The ...projectiles are accelerated by a two-stage light-gas gun. X-ray photography is used to observe the state of a projectile before its impact on the mesh bumper and the process of its fragmentation. The parameters of the cloud of fragments of the projectile are recorded using a thick witness plate made of AMg6 alloy placed behind the mesh bumper. Numerical simulation is performed by the smoothed particle hydrodynamic (SPH) method. Specific features of the morphology of the cloud of fragments are pointed out, and the velocities of the fragments in different parts of the cloud, as well as the arising cumulative effect, are estimated. The experimental results are compared with the results of numerical simulation.
—A new technique is proposed for analytical continuation of anomalous gravitational and magnetic fields based on constructing integral curves of the fields’ components in the context of the ...approximating approach. Results of the mathematical experiment using real data (of airborne magnetic and marine gravity surveys) are presented.
The Persistency Framework consists of three software packages (CORAL, COOL and POOL) addressing the data access requirements of the LHC experiments in different areas. It is the result of the ...collaboration between the CERN IT Department and the three experiments (ATLAS, CMS and LHCb) that use this software to access their data. POOL is a hybrid technology store for C++ objects, metadata catalogs and collections. CORAL is a relational database abstraction layer with an SQL-free API. COOL provides specific software tools and components for the handling of conditions data. This paper reports on the status and outlook of the project and reviews in detail the usage of each package in the three experiments.
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