356 research outputs found

    Use of information technology to increase economic efficiency and credibility in public administration in the context of digitization

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    Purpose: The article analyzes the use of information technologies to increase the level of economic efficiency and trust in public administration in Ukraine. Design/Methodology/Approach: We use the concept of digital management for the purpose of integrated interaction of municipal and state structures with business, civil society institutions and the population. Findings: The conducted research concludes the active digital transformation of public administration in Ukraine. The following trends in the use of information technology are identified: the development of institutional support; the creation of analytical portals for ensuring public control; the level of accountability, transparency, accountability of the activity of civil servants; the implementation of e-government projects; the changing philosophy of development of electronic services. Practical Implications: The concept of state policy in the field of digital infrastructure was developed on the basis of a multi-stakeholder approach according to which the main purpose of the state bodies is to identify, prioritize, harmonize and satisfy the stakeholders. Originality/Value: In this article, we show the level of individual regions in Ukraine where there is uneven implementation and use of e-learning tools management.peer-reviewe

    Is weak temperature dependence of electron dephasing possible?

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    The first-principle theory of electron dephasing by disorder-induced two state fluctuators is developed. There exist two mechanisms of dephasing. First, dephasing occurs due to direct transitions between the defect levels caused by inelastic electron-defect scattering. The second mechanism is due to violation of the time reversal symmetry caused by time-dependent fluctuations of the scattering potential. These fluctuations originate from an interaction between the dynamic defects and conduction electrons forming a thermal bath. The first contribution to the dephasing rate saturates as temperature decreases. The second contribution does not saturate, although its temperature dependence is rather weak, T1/3\propto T^{1/3}. The quantitative estimates based on the experimental data show that these mechanisms considered can explain the weak temperature dependence of the dephasing rate in some temperature interval. However, below some temperature dependent on the model of dynamic defects the dephasing rate tends rapidly to zero. The relation to earlier studies of the dephasing caused by the dynamical defects is discussed.Comment: 14 pages, 6 figures, submitted to PR

    Dephasing Times in a Non-degenerate Two-Dimensional Electron Gas

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    Studies of weak localization by scattering from vapor atoms for electrons on a liquid helium surface are reported. There are three contributions to the dephasing time. Dephasing by the motion of vapor atoms perpendicular to the surface is studied by varying the holding field to change the characteristic width of the electron layer at the surface. A change in vapor density alters the quasi-elastic scattering length and the dephasing due to the motion of atoms both perpendicular and parallel to the surface. Dephasing due to the electron-electron interaction is dependent on the electron density.Comment: 4 pages, Revte

    Wigner function properties for electromagnetic systems

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    Using the Wigner-Vlasov formalism, an exact 3D solution of the Schr\"odinger equation for a scalar particle in an electromagnetic field is constructed. Electric and magnetic fields are non-uniform. According to the exact expression for the wave function, the search for two types of the Wigner functions is conducted. The first function is the usual Wigner function with a modified momentum. The second Wigner function is constructed on the basis of the Weyl-Stratonovich transform in papers [Phys. Rev. A 35 2791 (1987)] or [Phys. Rev. B 99 014423 (2019)]. It turns out that the second function, unlike the first one, has areas of negative values for wave functions with the Gaussian distribution (Hudson's theorem). On the one hand, knowing the Wigner functions allows one to find the distribution of the mean momentum vector field and the energy spectrum of the quantum system. On the other hand, within the framework of the Wigner-Vlasov formalism, the mean momentum distribution and the magnitude of the energy are initially known. Consequently, the mean momentum distributions and energy values obtained according to the Wigner functions can be compared with the exact momentum distribution and energy values. This paper presents this comparison and describes the differences. For the first Wigner function, an analog of the Moyal equation with an electromagnetic part and the Hamilton-Jacobi operator equation are obtained. An operator analogue of the {\guillemotleft}motion equation{\guillemotright} with electromagnetic interaction is constructed. For the second Vlasov equation, an operator expression for the Vlasov-Moyal approximation for systems with electromagnetic interaction is obtained.Comment: 26 pages, 2 figure

    The Wigner function negative value domains and energy function poles of the polynomial oscillator

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    For a quantum oscillator with the polynomial potential an explicit expression that describes the energy distribution as a coordinate (and momentum) function is obtained. The presence of the energy function poles is shown for the quantum system in the domains where the Wigner function has negative values.Comment: 21 pages, 4 figure

    Effect of the entropy on the shear viscosity of metallic glasses near the glass transition

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    We measured the shear viscosity of 14 metallic glasses differing with their mixing entropy ΔSmix\Delta S_{mix}. It is found that the viscosity at the glass transition temperature TgT_g significantly increases with ΔSmix\Delta S_{mix}. Using calorimetric data, we calculated the excess entropy of all glasses ΔS\Delta S with respect to their maternal crystalline states as a function of temperature. It is shown that the excess entropy ΔS\Delta S both at room temperature and at TgT_g \textit{decreases} with ΔSmix\Delta S_{mix}. It is concluded that glasses with "high mixing entropy" ΔSmix\Delta S_{mix} correspond to MGs with \textit{low} excess entropy ΔS\Delta S. The origin of the increased shear viscosity at TgT_g of glasses with high ΔSmix\Delta S_{mix} is determined by their reduced excess entropy ΔS\Delta S.Comment: 12 pages, 4 Figure

    High entropy metallic glasses, what does it mean?

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    We performed calorimetric measurements on 30 bulk metallic glasses differing with their mixing entropies DSmix. On this basis, the excess entropies DS and excess enthalpies DH of glasses with respect to their maternal crystalline states are calculated. It is found that the excess entropy DS on the average decreases with increasing mixing entropy DSmix. This means that so-called "high-entropymetallic glasses" (i.e. the glasses having high DSmix) actually constitute glasses with low excess entropy DS. We predict that such glasses should have reduced relaxation ability. We also found that the excess enthalpy DH of glass linearly increases with its excess entropy DS, in line with a general thermodynamic estimate.Comment: 5 pages, 3 figure
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