140 research outputs found

    Local characterization of strongly convex sets

    Full text link
    Strongly convex sets in Hilbert spaces are characterized by local properties. One quantity which is used for this purpose is a generalization of the modulus of convexity \delta_\Omega of a set \Omega. We also show that \lim_{\epsilon \to 0} \delta_\Omega(\epsilon)/\epsilon^2 exists whenever \Omega is closed and convex

    An energy dissipative spatial discretization for the regularized compressible Navier-Stokes-Cahn-Hilliard system of equations

    Get PDF
    We consider the regularized 3D Navier-Stokes-Cahn-Hilliard equations describing isothermal flows of viscous compressible two-component fluids with interphase effects. We construct for them a new energy dissipative finite-difference discretization in space, i.e., with the non-increasing total energy in time. This property is preserved in the absence of a regularization. In addition, the discretization is well-balanced for equilibrium flows and the potential body force. The sought total density, mixture velocity and concentration of one of the components are defined at nodes of one and the same grid. The results of computer simulation of several 2D test problems are presented. They demonstrate advantages of the constructed discretization including the absence of the so-called parasitic currents

    Междисциплинарные проекты как способ формирования компетенций при реализации образовательных программ

    Get PDF
    Interdisciplinary project is one of the effective educational technologies used in MIET as a part of the competence building approach. The experience in the development of the methodical documents for such projects implementation is described in this paper. The list of recommended structural methodological elements for interdisciplinary project realization as a students’ competence building tool is proposed. In addition to this, the content of methodological support preparation stages is provided. The description of the courses sequence in the interdisciplinary project is given as an example

    Exchange coupling in transition-metal nano-clusters on Cu(001) and Cu(111) surfaces

    Full text link
    We present results of density-functional calculations on the magnetic properties of Cr, Mn, Fe and Co nano-clusters (1 to 9 atoms large) supported on Cu(001) and Cu(111). The inter-atomic exchange coupling is found to depend on competing mechanisms, namely ferromagnetic double exchange and antiferromagnetic kinetic exchange. Hybridization-induced broadening of the resonances is shown to be important for the coupling strength. The cluster shape is found to weaken the coupling via a mechanism that comprises the different orientation of the atomic d-orbitals and the strength of nearest-neighbour hopping. Especially in Fe clusters, a correlation of binding energy and exchange coupling is also revealed

    Value-Oriented Model of Tuition in the Context of University 3.0 Paradigm

    Get PDF
    Introduction. This article presents the analysis of transformational changes in the Russian system of higher education. The authors aimed to develop a value-oriented model for the organization of educational activities. The concept of University 3.0 serves as a modern basis for ensuring the global competitiveness of national economies in the digital world. Materials and Methods. The methodological approaches of the study were systematic, comparative and problem-chronological methods. Results. The study expanded the understanding of the main stages of transformation in the higher education system in the Russian Federation. The results show that the destruction of the Soviet academic culture was accompanied by the destruction of the historical institutional balance. As a result, it became necessary to form new norms that define both the rules of interaction within the educational community and the place of this community in the overall social structure. The concept of Education 3.0 is designed to form these normative frameworks and ensure their interiorisation both in the pedagogical community and among students. It is revealed that in the modern Russian educational environment they are formed spontaneously, mainly due to the independent development of new technologies by students, while teachers continue to adhere to the previous educational concepts. Discussion and Conclusion. The practical significance of the study lies in the proposal of specific measures, the implementation of which will form the reputation of the University, attract additional investment, enhance its competitiveness both at the domestic and international level. The timeliness of the study lies in the fact that the analysis of the educational reform was carried out taking into account the needs of value-based management. The results of the study will be useful for the management of higher education institutions to reformulate development concepts, as well as for the executive authorities to further reform the educational system

    Light-stimulated adaptive artificial synapse based on nanocrystalline metal-oxide film

    Get PDF
    Artificial synapses utilizing spike signals are essential elements of new generation brain-inspired computers. In this paper, we realize light-stimulated adaptive artificial synapse based on nanocrystalline zinc oxide film. The artificial synapse photoconductivity shows spike-type signal response, long and short-term memory (LTM and STM), STM-to-LTM transition and paired-pulse facilitation. It is also retaining the memory of previous exposures and demonstrates spike-frequency adaptation properties. A way to implement neurons with synaptic depression, tonic excitation, and delayed accelerating types of response under the influence of repetitive light signals is discussed. The developed artificial synapse is able to become a key element of neuromorphic chips and neuromorphic sensorics systems

    Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

    Full text link
    Core-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30MM_{\odot} for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure

    Potential of Core-Collapse Supernova Neutrino Detection at JUNO

    Get PDF
    JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve

    Detection of the Diffuse Supernova Neutrino Background with JUNO

    Get PDF
    As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO
    corecore