356 research outputs found
Use of information technology to increase economic efficiency and credibility in public administration in the context of digitization
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?
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, . 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
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
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
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
We measured the shear viscosity of 14 metallic glasses differing with their
mixing entropy . It is found that the viscosity at the glass
transition temperature significantly increases with .
Using calorimetric data, we calculated the excess entropy of all glasses
with respect to their maternal crystalline states as a function of
temperature. It is shown that the excess entropy both at room
temperature and at \textit{decreases} with . It is
concluded that glasses with "high mixing entropy" correspond
to MGs with \textit{low} excess entropy . The origin of the increased
shear viscosity at of glasses with high is determined by
their reduced excess entropy .Comment: 12 pages, 4 Figure
High entropy metallic glasses, what does it mean?
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
- …