2,555 research outputs found
Non-ergodicity of the motion in three dimensional steep repelling dispersing potentials
It is demonstrated numerically that smooth three degrees of freedom
Hamiltonian systems which are arbitrarily close to three dimensional strictly
dispersing billiards (Sinai billiards) have islands of effective stability, and
hence are non-ergodic. The mechanism for creating the islands are corners of
the billiard domain.Comment: 6 pages, 8 figures, submitted to Chao
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When a few undermine the whole: a class of social dilemmas in ridesharing
We investigate a class of social dilemmas that arise when a heterogeneous group of agents potentially benefit from a joint enterprise such as ridesharing. Participation in the enterprise incurs positive externalities to other participants; social welfare is maximized with full participation. However, if some agents find it a dominant strategy to opt out, then the potential benefit from the enterprise will decrease, leading to more members opting out. This iterated disincentivizing effect could result in massive welfare losses. We construct a game-theoretical model to implement these social dilemmas and report experimental evidence for their existence and welfare impact.NSF Grant SES-141892
Excitation of planetary electromagnetic waves in the inhomogeneous ionosphere
In this paper we develop a new method for the analysis of excitation and
propagation of planetary electromagnetic waves (PEMW) in the ionosphere of
the Earth. The nonlinear system of equations for PEMW, valid for any height,
from D to F regions, including intermediate altitudes between D and E and
between E and F regions, is derived. In particular, we have found the system
of nonlinear one-fluid MHD equations in the Ξ²-plane approximation valid
for the ionospheric F region (Aburjania et al., 2003a, 2005). The
series expansion in a "small" (relative to the local geomagnetic field)
non-stationary magnetic field has been applied only at the last step of the
derivation of the equations. The small mechanical vertical displacement of
the media is taken into account. We have shown that obtained equations can be
reduced to the well-known system with LarichevβReznik vortex solution in the
equatorial region (see e.g. Aburjania et al., 2002). The excitation of
planetary electromagnetic waves by different initial perturbations has been
investigated numerically. Some means for the PEMW detection and data
processing are discussed
Quantization of the Riemann Zeta-Function and Cosmology
Quantization of the Riemann zeta-function is proposed. We treat the Riemann
zeta-function as a symbol of a pseudodifferential operator and study the
corresponding classical and quantum field theories. This approach is motivated
by the theory of p-adic strings and by recent works on stringy cosmological
models. We show that the Lagrangian for the zeta-function field is equivalent
to the sum of the Klein-Gordon Lagrangians with masses defined by the zeros of
the Riemann zeta-function. Quantization of the mathematics of Fermat-Wiles and
the Langlands program is indicated. The Beilinson conjectures on the values of
L-functions of motives are interpreted as dealing with the cosmological
constant problem. Possible cosmological applications of the zeta-function field
theory are discussed.Comment: 14 pages, corrected typos, references and comments adde
Cooperation amongst competing agents in minority games
We study a variation of the minority game. There are N agents. Each has to
choose between one of two alternatives everyday, and there is reward to each
member of the smaller group. The agents cannot communicate with each other, but
try to guess the choice others will make, based only the past history of number
of people choosing the two alternatives. We describe a simple probabilistic
strategy using which the agents acting independently, can still maximize the
average number of people benefitting every day. The strategy leads to a very
efficient utilization of resources, and the average deviation from the maximum
possible can be made of order , for any . We also
show that a single agent does not expect to gain by not following the strategy.Comment: 7 pages, 5 eps figure
Functional solution for comfortable parking of the personal motor transport
In the paper, a system for automated accounting and assignment of parking spaces near big shopping centers is described. A comparative analysis of existing parking management systems is presented. The project described in the paper could be interesting for household management companies, shopping centers, and security services. A comfortable parking increases attractiveness of a place and could lead to sales growth. Smart parking is the part of a smart city creation.Π ΡΡΠ°ΡΡΠ΅ ΠΎΠΏΠΈΡΠ°Π½Π° ΡΠΈΡΡΠ΅ΠΌΠ°, ΠΏΡΠ΅Π΄Π½Π°Π·Π½Π°ΡΠ΅Π½Π½Π°Ρ Π΄Π»Ρ Π°Π²ΡΠΎΠΌΠ°ΡΠΈΠ·ΠΈΡΠΎΠ²Π°Π½Π½ΠΎΠ³ΠΎ ΡΡΠ΅ΡΠ° ΠΈ ΡΠ°ΡΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΡ ΠΏΠ°ΡΠΊΠΎΠ²ΠΎΡΠ½ΡΡ
ΠΌΠ΅ΡΡ Π½Π° Π°Π²ΡΠΎΡΡΠΎΡΠ½ΠΊΠ°Ρ
. ΠΡΠΈΠ²ΠΎΠ΄ΠΈΡΡΡ Π°Π½Π°Π»ΠΈΠ· ΡΡΡΠ΅ΡΡΠ²ΡΡΡΠΈΡ
ΡΠΈΡΡΠ΅ΠΌ ΡΠΏΡΠ°Π²Π»Π΅Π½ΠΈΡ ΠΏΠ°ΡΠΊΠΎΠ²ΠΊΠΎΠΉ, ΠΎΡΠΌΠ΅ΡΠ°ΡΡΡΡ ΠΈΡ
Π΄ΠΎΡΡΠΎΠΈΠ½ΡΡΠ²Π° ΠΈ Π½Π΅Π΄ΠΎΡΡΠ°ΡΠΊΠΈ. ΠΠ²ΡΠΎΡΡ ΠΏΠΎΠ»Π°Π³Π°ΡΡ, ΡΡΠΎ ΠΏΡΠ΅Π΄ΡΡΠ°Π²Π»Π΅Π½Π½ΡΠΉ ΠΏΡΠΎΠ΅ΠΊΡ ΠΌΠΎΠΆΠ΅Ρ ΠΏΡΠ΅Π΄ΡΡΠ°Π²Π»ΡΡΡ ΠΈΠ½ΡΠ΅ΡΠ΅Ρ Π΄Π»Ρ ΡΠΏΡΠ°Π²Π»ΡΡΡΠΈΡ
ΠΎΡΠ³Π°Π½ΠΈΠ·Π°ΡΠΈΠΉ ΡΠΎΡΠ³ΠΎΠ²ΡΡ
ΡΠ΅Π½ΡΡΠΎΠ² ΠΈ ΡΠ»ΡΠΆΠ± Π±Π΅Π·ΠΎΠΏΠ°ΡΠ½ΠΎΡΡΠΈ. ΠΠΎΠΌΡΠΎΡΡΠ½ΠΎΠ΅ ΠΏΡΠ΅Π±ΡΠ²Π°Π½ΠΈΠ΅ Π²ΠΎΠ΄ΠΈΡΠ΅Π»Π΅ΠΉ Π½Π° ΠΏΠ°ΡΠΊΠΎΠ²ΠΊΠ΅ ΡΠ²Π΅Π»ΠΈΡΠΈΠ²Π°Π΅Ρ ΠΏΡΠΈΠ²Π»Π΅ΠΊΠ°ΡΠ΅Π»ΡΠ½ΠΎΡΡΡ ΡΠ°ΠΊΠΎΠ³ΠΎ ΠΎΠ±ΡΠ΅ΠΊΡΠ° ΠΈ ΠΏΠΎΠ²ΡΡΠ°Π΅Ρ ΡΠΏΡΠΎΡ Π½Π° ΠΏΡΠ΅Π΄ΠΎΡΡΠ°Π²Π»ΡΠ΅ΠΌΡΠ΅ ΡΡΠ»ΡΠ³ΠΈ. Π£ΠΌΠ½Π°Ρ ΠΏΠ°ΡΠΊΠΎΠ²ΠΊΠ° ΡΠ²Π»ΡΠ΅ΡΡΡ ΠΎΠ΄Π½ΠΈΠΌ ΠΈΠ· Π½Π°ΠΏΡΠ°Π²Π»Π΅Π½ΠΈΠΉ Π² ΡΠ΅Π°Π»ΠΈΠ·Π°ΡΠΈΠΈ ΡΠΌΠ½ΠΎΠ³ΠΎ Π³ΠΎΡΠΎΠ΄Π°
New possibilities of modern web-programming
Π‘ΡΠ°ΡΡΡ ΠΏΠΎΡΠ²ΡΡΠ΅Π½Π° ΡΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΡΠΌ ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΡΠΌ Π²Π΅Π±-ΠΏΡΠΎΠ³ΡΠ°ΠΌΠΌΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΈ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΡ Π½ΠΎΠ²ΡΡ
ΡΠ΅Ρ
Π½ΠΈΡΠ΅ΡΠΊΠΈΡ
Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎΡΡΠ΅ΠΉ Π² ΡΠ΅Π°Π»ΡΠ½ΡΡ
ΠΏΡΠΎΠ΅ΠΊΡΠ°Ρ
ΠΏΠΎ ΡΠΎΠ·Π΄Π°Π½ΠΈΡ ΠΏΡΠΎΠ³ΡΠ°ΠΌΠΌΠ½ΠΎΠ³ΠΎ ΠΎΠ±Π΅ΡΠΏΠ΅ΡΠ΅Π½ΠΈΡ. Π ΡΡΠ°ΡΡΠ΅ ΠΎΠΏΠΈΡΠ°Π½Ρ Π½ΠΎΠ²Π΅ΠΉΡΠΈΠ΅ ΡΡΠ΅ΠΉΠΌΠ²ΠΎΡΠΊΠΈ Π΄Π»Ρ ΡΠΎΠ·Π΄Π°Π½ΠΈΡ ΠΊΠ»ΠΈΠ΅Π½ΡΡΠΊΠΎΠΉ ΡΠ°ΡΡΠΈ Π²Π΅Π±-ΠΏΡΠΈΠ»ΠΎΠΆΠ΅Π½ΠΈΡ, Π° ΡΠ°ΠΊΠΆΠ΅ ΡΠ°ΡΡΠΊΠ°Π·Π°Π½ΠΎ ΠΎ ΠΏΡΠΎΠ³ΡΠ°ΠΌΠΌΠ½ΠΎΠΉ ΡΠ΅Π°Π»ΠΈΠ·Π°ΡΠΈΠΈ Π²Π΅Π±-ΠΏΡΠΈΠ»ΠΎΠΆΠ΅Π½ΠΈΡ Π½Π° ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΠΈ React. Π¦Π΅Π»ΡΡ ΡΠΎΠ·Π΄Π°Π½ΠΈΡ ΠΏΡΠΎΠ³ΡΠ°ΠΌΠΌΠ½ΠΎΠΉ ΡΠ΅Π°Π»ΠΈΠ·Π°ΡΠΈΠΈ ΡΠ²Π»ΡΠ΅ΡΡΡ Π½Π°Π³Π»ΡΠ΄Π½Π°Ρ Π΄Π΅ΠΌΠΎΠ½ΡΡΡΠ°ΡΠΈΡ ΠΏΡΠ΅ΠΈΠΌΡΡΠ΅ΡΡΠ² ΠΈΠ½Π½ΠΎΠ²Π°ΡΠΈΠΎΠ½Π½ΡΡ
ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΠΉ Π²Π΅Π±-ΠΏΡΠΎΠ³ΡΠ°ΠΌΠΌΠΈΡΠΎΠ²Π°Π½ΠΈΡ Π² ΡΠΎΠ·Π΄Π°Π½ΠΈΠΈ ΠΈ Π²Π½Π΅Π΄ΡΠ΅Π½ΠΈΠΈ Π²Π΅Π±-ΠΏΡΠΈΠ»ΠΎΠΆΠ΅Π½ΠΈΠΉ Π½Π°Π΄ ΡΡΡΠ°ΡΠ΅Π²ΡΠΈΠΌΠΈ ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΡΠΌΠΈ.The article is devoted to modern web programming techniques and to using new technological possibilities in real projects of software engineering. The article tells about the newest frameworks used to make a client of a web application, as well as about web application implementation using React. The goal of the implementation is to clearly demonstrate the advantages of innovative web programming techniques in creating web applications over the deprecated techniques
Enhanced inverse bremsstrahlung heating rates in a strong laser field
Test particle studies of electron scattering on ions, in an oscillatory
electromagnetic field have shown that standard theoretical assumptions of small
angle collisions and phase independent orbits are incorrect for electron
trajectories with drift velocities smaller than quiver velocity amplitude. This
leads to significant enhancement of the electron energy gain and the inverse
bremsstrahlung heating rate in strong laser fields. Nonlinear processes such as
Coulomb focusing and correlated collisions of electrons being brought back to
the same ion by the oscillatory field are responsible for large angle, head-on
scattering processes. The statistical importance of these trajectories has been
examined for mono-energetic beam-like, Maxwellian and highly anisotropic
electron distribution functions. A new scaling of the inverse bremsstrahlung
heating rate with drift velocity and laser intensity is discussed.Comment: 12 pages, 12 figure
Ground-based acoustic parametric generator impact on the atmosphere and ionosphere in an active experiment
We develop theoretical basics of active experiments with two beams of acoustic waves, radiated by a ground-based sound generator. These beams are transformed into atmospheric acoustic gravity waves (AGWs), which have parameters that enable them to penetrate to the altitudes of the ionospheric E and F regions where they influence the electron concentration of the ionosphere. Acoustic waves are generated by the ground-based parametric sound generator (PSG) at the two close frequencies. The main idea of the experiment is to design the output parameters of the PSG to build a cascade scheme of nonlinear wave frequency downshift transformations to provide the necessary conditions for their vertical propagation and to enable penetration to ionospheric altitudes. The PSG generates sound waves (SWs) with frequencies f1 = 600 and f2 = 625 Hz and large amplitudes (100-420ms-1). Each of these waves is modulated with the frequency of 0.016 Hz. The novelty of the proposed analytical-numerical model is due to simultaneous accounting for nonlinearity, diffraction, losses, and dispersion and inclusion of the two-stage transformation (1) of the initial acoustic waves to the acoustic wave with the difference frequency Ξf = f2 - f1 in the altitude ranges 0-0.1 km, in the strongly nonlinear regime, and (2) of the acoustic wave with the difference frequency to atmospheric acoustic gravity waves with the modulational frequency in the altitude ranges 0.1-20 km, which then reach the altitudes of the ionospheric E and F regions, in a practically linear regime. AGWs, nonlinearly transformed from the sound waves, launched by the two-frequency ground-based sound generator can increase the transparency of the ionosphere for the electromagnetic waves in HF (MHz) and VLF (kHz) ranges. The developed theoretical model can be used for interpreting an active experiment that includes the PSG impact on the atmosphere-ionosphere system, measurements of electromagnetic and acoustic fields, study of the variations in ionospheric transparency for the radio emissions from galactic radio sources, optical measurements, and the impact on atmospheric aerosols. The proposed approach can be useful for better understanding the mechanism of the acoustic channel of seismo-ionospheric coupling
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