scholarly journals A statistically significant long term characteristic time-scale of test size variation of Calcareous Trochospiral Benthic Foraminifera (CTBF) during the past 120 m.y.

2003 ◽  
Vol 30 (5) ◽  
pp. n/a-n/a ◽  
Author(s):  
R. K. Tiwari ◽  
K. N. N. Rao
Keyword(s):  
Benthic Foraminifera ◽  
Time Scale ◽  
Characteristic Time ◽  
Size Variation ◽  
Characteristic Time Scale ◽  
Test Size ◽  
The Past

Effect of Particle Residence Time on Particle Dispersion in a Plane Mixing Layer

1993 ◽  
Vol 115 (4) ◽  
pp. 751-759 ◽  
Author(s):  
Tsuneaki Ishima ◽  
Koichi Hishida ◽  
Masanobu Maeda
Keyword(s):  
Gas Phase ◽  
Residence Time ◽  
Time Scale ◽  
Characteristic Time ◽  
Mixing Layer ◽  
Particle Dispersion ◽  
Laser Doppler Velocimeter ◽  
Characteristic Time Scale ◽  
Two Phase ◽  
Particle Residence Time

A particle dispersion has been experimentally investigated in a two-dimensional mixing layer with a large relative velocity between particle and gas-phase in order to clarify the effect of particle residence time on particle dispersion. Spherical glass particles 42, 72, and 135 μm in diameter were loaded directly into the origin of the shear layer. Particle number density and the velocities of both particle and gas phase were measured by a laser Doppler velocimeter with modified signal processing for two-phase flow. The results confirmed that the characteristic time scale of the coherent eddy apparently became equivalent to a shorter characteristic time scale due to a less residence time. The particle dispersion coefficients were well correlated to the extended Stokes number defined as the ratio of the particle relaxation time to the substantial eddy characteristic time scale which was evaluated by taking account of the particle residence time.

UNIVERSAL MULTIFRACTAL CHARACTERIZATION AND SIMULATION OF SPEECH

1992 ◽  
Vol 02 (03) ◽  
pp. 715-719
Author(s):  
CHRIS LARNDER ◽  
NICOLAS DESAULNIERS-SOUCY ◽  
SHAUN LOVEJOY ◽  
DANIEL SCHERTZER ◽  
CLAUDE BRAUN ◽  
...  
Keyword(s):  
Time Scale ◽  
Scale Invariance ◽  
Characteristic Time ◽  
Low Frequency ◽  
Characteristic Time Scale ◽  
Low Frequencies ◽  
Universal Behavior ◽  
Nonlinear Mixing

In the 1970's it was found that; for low frequencies (<10 Hz), speech is scaling: it has no characteristic time scale. Now such scale invariance is associated with multiscaling statistics, and multifractal structures. Just as Gaussian noises frequently arise because they are generically produced by sums of many independent noise processes, scaling noises have an analogous universal behavior arising from nonlinear mixing of processes. We show that low frequency speech is consistent with these ideas, and use the measured parameters to produce stochastic speech simulations which are strikingly similar to real speech.

Daytime efficiency and characteristic time scale of interplanetary electric fields penetration to equatorial latitude ionosphere

2011 ◽  
Vol 73 (11-12) ◽  
pp. 1555-1559 ◽  
Author(s):  
C.M. Denardini ◽  
H.C. Aveiro ◽  
P.D.S.C. Almeida ◽  
L.C.A. Resende ◽  
L.M. Guizelli ◽  
...  
Keyword(s):  
Electric Fields ◽  
Time Scale ◽  
Characteristic Time ◽  
Characteristic Time Scale ◽  
Equatorial Latitude

scholarly journals Radio Flux Flicker of Extragalactic Sources

1982 ◽  
Vol 97 ◽  
pp. 327-328
Author(s):  
D. S. Heeschen
Keyword(s):  
Time Scale ◽  
Characteristic Time ◽  
Characteristic Time Scale ◽  
Radio Flux ◽  
Wavelength Radiation ◽  
Compact Sources

Compact sources (compactness evidenced by flat/complex spectra) display a “flicker” in their intrinsic centimeter wavelength radiation, with an amplitude of about 2% and a characteristic time scale of a few days.

scholarly journals Meteorological controls on glacier mass balance: empirical relations suggested by measurements on glacier de Sarennes, France

1997 ◽  
Vol 43 (143) ◽  
pp. 131-137 ◽  
Author(s):  
C. Vincent ◽  
M. Vallon
Keyword(s):  
Mass Balance ◽  
Time Scale ◽  
Meteorological Data ◽  
Empirical Relation ◽  
Glacier Mass Balance ◽  
Glacier Surface ◽  
Surface Conditions ◽  
The Past ◽  
Empirical Relations

AbstractGlacial mass-balance reconstruction for a long-term time-scale requires knowledge of the relation between climate change and mass-balance fluctuations. A large number of mass-balance reconstructions since the beginning of the century are based on statistical relations between monthly meteorological data and mass balance. The question examined in this paper is: are these relationships reliable enough for long-term time-scale extrapolation? From the glacier de Sarennes long mass-balance observations series, we were surprised to discover large discrepancies between relations resulting from different time periods. The importance of the albedo in relation to ablation and mass balance is highlighted, and it is shown that it is impossible to ignore glacier-surface conditions in establishing the empirical relation between mass-balance fluctuations and climatic variation; to omit this parameter leads to incorrect results for mass-balance reconstruction in the past based on meteorological data.

scholarly journals Does the Radio Luminosity of Pulsar Grow up in its Later Stage?

1987 ◽  
Vol 125 ◽  
pp. 50-50
Author(s):  
T. Lu ◽  
P. C. Zhu ◽  
J. S. Kui
Keyword(s):  
Time Scale ◽  
Characteristic Time ◽  
Statistical Analyses ◽  
Striking Feature ◽  
Characteristic Time Scale ◽  
Radio Luminosity ◽  
Mean Values ◽  
The Mean

In usual statistical analyses, because of diversities of proper parameters of pulsars, some interesting features might be smeared. In order to remove these diversities, we use the mean values for all quantities of pulsars, instead of values of individual pulsar, to do statistical analyses. logP/P3 - log τ and logL - logτ have been plotted, here τ P/2P and L denote the characteristic time scale and the radio luminosity of pulsars respectively. The most striking feature is that after its initial dropping to a dip at about τ∼106 yrs, the radio luminosity of pulsar appears to grow up evidently and then redrop again. This feature is difficult to be understood in usual models. However, two tentative interpretations have been given in this paper.

The characteristic time scale for basin hydrological response using radar data

2001 ◽  
Vol 252 (1-4) ◽  
pp. 85-99 ◽  
Author(s):  
Efrat Morin ◽  
Yehouda Enzel ◽  
Uri Shamir ◽  
Rami Garti
Keyword(s):  
Time Scale ◽  
Characteristic Time ◽  
Radar Data ◽  
Characteristic Time Scale ◽  
Hydrological Response

Role of thermal conduction in the expansion of a plasma from a vacuum interface

1988 ◽  
Vol 66 (8) ◽  
pp. 662-673 ◽  
Author(s):  
D. Parfeniuk ◽  
A. Ng ◽  
P. Celliers
Keyword(s):  
Time Scale ◽  
Thermal Conduction ◽  
Characteristic Time ◽  
Characteristic Time Scale ◽  
Rarefaction Waves ◽  
Vacuum Interface ◽  
Aluminum Plasma ◽  
Self Similar ◽  
Expansion Model ◽  
Isotropic Expansion

The effects of thermal conduction are examined for the expansion of a plasma from a vacuum interface using an analytic model based on well-known self-similar models of rarefaction waves. Conventional analysis of shock-unloading experiments uses an isotropic expansion model. However, thermal conduction introduces a characteristic time scale during which the flow is not self-similar. The significance of this time scale for experimental measurements is also discussed. The characteristic time is calculated for an aluminum plasma using theoretical equation-of-state and conductivity models.

The ‘Hurst phenomenon’ in grid turbulence

1978 ◽  
Vol 85 (3) ◽  
pp. 573-589 ◽  
Author(s):  
K. N. Helland ◽  
C. W. Van Atta
Keyword(s):  
Wind Tunnel ◽  
Time Scale ◽  
Characteristic Time ◽  
Time Interval ◽  
Characteristic Time Scale ◽  
Grid Turbulence ◽  
Mean Velocity ◽  
Statistical Tool ◽  
Rescaled Range ◽  
Rescaled Range Analysis

Measurements of the statistical property called the ‘rescaled range’ in grid-generated turbulence exhibit a Hurst coefficient H = 0·5 for 43 < UT/M < 1850, where M/U is a characteristic time scale associated with the grid size M and mean velocity U. Theory predicts that H = 0·5 for independence of two observations separated by a time interval T, and the deviation from H = 0·5 is referred to as the ‘Hurst phenomenon’. The rescaled range obtained for grid turbulence contains an initial region UT/M < 43 of large H, approaching 1·0, corresponding approximately to the usual region of a finite non-zero autocorrelation of turbulent velocity fluctuations. For UT/M > 1850 the rescaled range breaks from H = 0·5 and rises at a significantly faster rate, H = 0·7-0·8, implying a long-term dependence or possibly non-stationarity at long times. The measured autocorrelations remain indistinguishable from zero for UT/M > 20. The break in the trend H = 0·5 is probably caused by motions on scales comparable to characteristic time scales of the wind-tunnel circulation. Rescaled-range analysis is a powerful statistical tool for determining the time scale separating the grid turbulence from the background wind-tunnel motions.

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