11,576 research outputs found
On the puzzling feature of the silence of precursory electromagnetic emissions
It has been suggested that fracture-induced MHz-kHz electromagnetic (EM)
emissions, which emerge from a few days up to a few hours before the main
seismic shock occurrence permit a real-time monitoring of the damage process
during the last stages of earthquake preparation, as it happens at the
laboratory scale. Despite fairly abundant evidence, EM precursors have not been
adequately accepted as credible physical phenomena. These negative views are
enhanced by the fact that certain 'puzzling features' are repetitively observed
in candidate fracture-induced pre-seismic EM emissions. More precisely, EM
silence in all frequency bands appears before the main seismic shock
occurrence, as well as during the aftershock period. Actually, the view that
'acceptance of 'precursive' EM signals without convincing co-seismic signals
should not be expected' seems to be reasonable. In this work we focus on this
point. We examine whether the aforementioned features of EM silence are really
puzzling ones or, instead, reflect well-documented characteristic features of
the fracture process, in terms of: universal structural patterns of the
fracture process, recent laboratory experiments, numerical and theoretical
studies of fracture dynamics, critical phenomena, percolation theory, and
micromechanics of granular materials. Our analysis shows that these features
should not be considered puzzling.Comment: arXiv admin note: text overlap with arXiv:cond-mat/0603542 by other
author
Research into the formation of a soccer curriculum in early childhood education Through the action research with students belonging to IPU’s soccer club and nursery school children
This six-month research examined the influence of playing soccer on the mental and physical development of 5 year old nursery school children under the corporation of students from IPU’s soccer club. Our objectives were to observe: 1) how soccer is a stimulative for young children as a content of early childhood education, 2) what kinds of effects children gain from a developmental point of view. 3) the possibility developing a new area of the early childhood education and care. Our conclusions suggest the following findings: 1)soccer is effective for improving children\u27s health, motor skills and the formation of human relations ability, 2)the most important coaching method for young children is child-oriented[without strong teacher intervention eacherintervention]as children develop their ability in small group, 3)it provides numerous chances to understand each child’s personality more deeply through such activities
Sudden drop of fractal dimension of electromagnetic emissions recorded prior to significant earthquake
The variation of fractal dimension and entropy during a damage evolution
process, especially approaching critical failure, has been recently
investigated. A sudden drop of fractal dimension has been proposed as a
quantitative indicator of damage localization or a likely precursor of an
impending catastrophic failure. In this contribution, electromagnetic emissions
recorded prior to significant earthquake are analysed to investigate whether
they also present such sudden fractal dimension and entropy drops as the main
catastrophic event is approaching. The pre-earthquake electromagnetic time
series analysis results reveal a good agreement to the theoretically expected
ones indicating that the critical fracture is approaching
Fractal Markets Hypothesis and the Global Financial Crisis: Scaling, Investment Horizons and Liquidity
We investigate whether fractal markets hypothesis and its focus on liquidity
and invest- ment horizons give reasonable predictions about dynamics of the
financial markets during the turbulences such as the Global Financial Crisis of
late 2000s. Compared to the mainstream efficient markets hypothesis, fractal
markets hypothesis considers financial markets as com- plex systems consisting
of many heterogenous agents, which are distinguishable mainly with respect to
their investment horizon. In the paper, several novel measures of trading
activity at different investment horizons are introduced through scaling of
variance of the underlying processes. On the three most liquid US indices -
DJI, NASDAQ and S&P500 - we show that predictions of fractal markets hypothesis
actually fit the observed behavior quite well.Comment: 11 pages, 3 figure
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