493 research outputs found
According to Chronicles, Did the “Route from the Varangians to the Greeks” Go by Sea or Overland?
This article deals with the historical and geographical analysis of the description of the “Route from the Varangians to the Greeks” — a key reference point in the system of spatial coordinates of the Primary Chronicle. The author reconsiders the “ultra-philological” approaches to this description and the cosmographic introduction of the Primary Chronicle as a purely literary (and manuscript) reality and argues in favor of the real geographical basis of the passage about the “Route from the Varangians to the Greeks”. Contrary to the traditional historiographical idea, the scheme mainly reflects not the water, but the overland route covered by the hypothetical author of this passage. Firstly, this is indicated by the obvious view of the “Route from the Varangians to the Greeks” “from land” (волоки), and not “from the river / sea”. Secondly, the medieval word usage of the term “волок” in the sense of a land route through a vast watershed space and at the same time about this space itself, which finds analogies not only in Old Russian sources but also in at least one medieval Icelandic text. The author draws a comparison of the building activity of prince Vsevolod Yaroslavich with his special attitude to the cult of Andrew the Apostle which makes it possible to assume that the author of the description of the “Route from the Varangians to the Greeks” was Metropolitan Ephrem of Pereyaslavl. Being of Greek origin, Ephrem entered the close circle of Vsevolod Yaroslavich after his marriage to the daughter of the Byzantine Emperor Constantine IX Monomachos. Ephrem personally made a journey along the “route from the Varangians to the Greeks” and left a topographically detailed description typical of Greek (Byzantine) culture, i.e. an eye-witness observation. In accordance with Christian cosmography, his task was to “normalize” the vast territory of Rus’ which had never been part of the universal Roman imperial (and later Christian) order
Dynamic metastable vortex states in interacting vortex lines
The electron transport in current-biased superconducting nano-bridges is
determined by the motion of the quantum vortex confined in the internal
disorder landscape. Here we consider a simple case of a single or two
neighbouring linear defects crossing a nano-bridge. The strong anharmonicity of
the vortex motion along the defect leads, upon RF-excitation, to fractional
Shapiro steps. In the case of two defects, the vortex motion becomes
correlated, characterized by metastable states that can be locked to a resonant
RF-drive. The lock-unlock process causes sudden voltage jumps and drops in the
voltage-current characteristics observed in experiments. We analyze the
parameters promoting these metastable dynamic states and discuss their
potential applications in quantum devices.Comment: 9 pages, 8 figure
Dynamics of relativistic solitons
Relativistic solitons are self-trapped, finite size, electromagnetic waves of
relativistic intensity that propagate without diffraction spreading. They have
been predicted theoretically within the relativistic fluid approximation, and
have been observed in multi-dimensional particle in cell simulations of laser
pulse interaction with the plasma. Solitons were observed in the laser
irradiated plasmas with the proton imaging technique as well. This paper
reviews many theoretical results on relativistic solitons in electron-ion
plasmas.Comment: 12th International Congress on Plasma Physics, 25-29 October 2004,
Nice (France
Pulsational Pair-instability Supernovae. II. Neutrino Signals from Pulsations and Their Detection by Terrestrial Neutrino Detectors
A Pulsational Pair-instability supernova (PPISN) evolves from a massive star with a mass ~80–140 M⊙ that develops electron–positron pair-instability after hydrostatic He-burning in the core has finished. In Leung et al. (Paper I), we examined the evolutionary tracks and the pulsational mass-loss history of this class of stars. In this paper, we analyze the thermodynamical history to explore the neutrino observables of PPISNe. We compute the neutrino light curves and spectra during pulsation. We then study the detailed neutrino emission profiles of these stars and estimate the expected neutrino detection count for different terrestrial neutrino detectors, including, e.g., KamLAND and Super-Kamiokande. Finally, we compare the neutrino pattern of PPISN with other types of supernovae based on a canonical 10 kt detector. The predicted neutrino signals can provide an early warning for telescopes to trace for the early time optical signals. The implications of neutrino physics on the expected detection are also discussed
Harmonic generation enhancement due to interaction of few-cycle light pulses in nonlinear dielectric coating on a mirror
We theoretically investigate reflection of a few-cycle light pulse from a mirror with nonlinear dielectric coating. We employ a nonlinear equation that describes spatiotemporal evolution of a few-cycle light pulse with a broad spectrum that lies in the transparency range of nonlinear dielectric media. This model is formulated directly for the electric field without slowly varying amplitude approximation. Analytical and numerical analysis shows that counter-propagating wave interactions in thin films can strongly enhance or suppress third harmonic generation of the central frequency, whereas this effect is neglected in the framework of slowly varying amplitude approximation
The dynamic model of enterprise revenue management
The article presents the dynamic model of enterprise revenue management. This model is based on the quadratic criterion and linear control law. The model is founded on multiple regression that links revenues with the financial performance of the enterprise. As a result, optimal management is obtained so as to provide the given enterprise revenue, namely, the values of financial indicators that ensure the planned profit of the organization are acquired
Water Demand Forecasting using Deep Learning in IoT Enabled Water Distribution Network
Most of the water losses occur during water distribution in pipelines during transportation. In order to eradicate the losses, an “IoT based water distribution system” integrated with “Fog and Cloud Computing" proposed for water distribution and underground health monitoring of pipes. For developing an effective water distribution system based on Internet of Things (IoT), the demand of the consumer should be analysed. So, towards predicting the water demand for consumers, Deep learning methodology called Long Short-Term Memory (LSTM) is compared with traditional Time Series methodology called Auto Regressive Integrated Moving Average (ARIMA) in terms of error and accuracy. Now based on demand prediction with higher accuracy, an IoT integrated “Water Distribution Network (WDN)” is designed using hydraulic engineering. This WDN design will ensure minimal losses during transportation and quality of water to the consumers. This will lead to development of a smart system for water distribution
- …