Temporal and spatial fluctuations in MOSFETs

The evaluation of temporal and spatial fluctuations of energy using compressible fluid analysis is proposed as an effective method to clarify the fundamental mechanism of the self-sustained oscilla-tions in a actual recorder. The main factors of the self-sustained oscillations are investigated in more detail by evaluating not only the steady state of the sound where the flow field and the sound field are completely coupled, but also the characteristics at the attack transient of the sound before the coupling is established. By analyzing the large energy fluctuations that occur just below the edge of the labium in the attack transient, it was shown that this phenomenon may be one of the main causes of the self-sustained oscillations. And the characteristics of the energy fluctuations and sound power generation during the steady state of the sound are discussed. It was also focused on the energy variations in another region that is near the exit of the windway.

Download Full-text

Temporal and Spatial Fluctuations in Widths of solar Euv Lines

International Astronomical Union Colloquium ◽

10.1017/s0252921100075205 ◽

1980 ◽

Vol 51 ◽

pp. 53-53

Author(s):

R.G. Athay ◽

O.R. White

Keyword(s):

Line Width ◽

Sound Speed ◽

Large Scale ◽

Small Cells ◽

The Sun ◽

Doppler Shifts ◽

Spatial Fluctuations ◽

Local Sound ◽

Line Widths ◽

Temporal And Spatial

AbstractAnalyses of some 300 hours of time sequences of solar EUV line profiles obtained with 0S0-8 show large fluctuations in line widths. At a given location on the sun, line widths fluctuate temporally on time scales ranging from less than a minute to over an hour. At any given time, line widths fluctuate spatially on a variety of scales ranging from active region size to arc second size. Temporal and spatial fluctuations are of approximately the same amplitude. Thus, the sun can be characterized by an aggregate of small cells in each of which line widths are fluctuating in time and which have random phases with respect to each other.Spatial fluctuations in line width are correlated with large scale spatial fluctuations in brightness for some lines but not for others. Temporal fluctuations in width are sometimes correlated with either Doppler shifts or intensity fluctuations, but more often such correlations are absent.For a given line, the line width varies through an extreme range of about a factor of two. Nonthermal components of line width vary from approximately the local sound speed to a small fraction of the sound speed.

Download Full-text

Balloon observations of temporal and spatial fluctuations in stratospheric conductivity

Advances in Space Research ◽

10.1016/j.asr.2005.04.009 ◽

2005 ◽

Vol 35 (8) ◽

pp. 1434-1449 ◽

Cited By ~ 10

Author(s):

Edgar A. Bering ◽

Robert H. Holzworth ◽

Brandon D. Reddell ◽

Michael F. Kokorowski ◽

Akira Kadokura ◽

...

Keyword(s):

Spatial Fluctuations ◽

Temporal And Spatial

Download Full-text

Estimation of signal reception probability characteristics using models of fading transionosphere channels

Journal of Radio Electronics ◽

10.30898/1684-1719.2020.11.7 ◽

2020 ◽

Vol 2020 (11) ◽

Author(s):

L.E. Nazarov ◽

◽

V.M. Smirnov ◽

Keyword(s):

Phase Shift ◽

Distribution Density ◽

Empirical Distribution ◽

Phase Shift Keying ◽

Digital Signals ◽

Rician Distribution ◽

Spatial Fluctuations ◽

Shift Keying ◽

Temporal And Spatial ◽

Signal Fading

Statistical models of narrow-band transionosphere channels, which determine the occurrence of signal fading due to random temporal and spatial fluctuations of the electron density of ionospheric irregularities, are considered. Fading models are based on the use of empirical relationships with respect to the distribution density of the amplitude of the signals at the output of the transionosphere channel as a random process. The parameters of empirical distribution densities (lognormal distribution, m-Nakagami distribution, Rician distribution) are related to the scintillation coefficient of signal fading. Using the considered models of signal fading, a technique is presented for estimating the probability of erroneous reception of digital signals with phase shift keying during reception. Using this technique, estimates of energy losses with respect to propagation in free space were made, reaching 0.001 for a scintillation coefficient value of 0.5 to 3 dB for signals with 2- and 4-phase shift keying.

Download Full-text

Seasonal and spatial distribution of Bacterioplankton in a fluvial-lagunar system of a tropical region: density, biomass, cellular volume and morphologic variation

Brazilian Archives of Biology and Technology ◽

10.1590/s1516-89132008000100024 ◽

2008 ◽

Vol 51 (1) ◽

pp. 203-212 ◽

Cited By ~ 9

Author(s):

Magnólia Fernandes Florêncio de Araújo ◽

Mirna Januária Leal Godinho

Keyword(s):

Bacterial Abundance ◽

Bacterial Biomass ◽

Tropical Region ◽

Small Oscillations ◽

Cellular Volume ◽

Spatial Fluctuations ◽

Spatial Differences ◽

Morphologic Variation ◽

Temporal And Spatial ◽

Positive Correlations

The temporal and spatial fluctuations of Bacterioplankton in a fluvial-lagunar system of a tropical region (Pitimbu River and Jiqui Lake, RN) were studied during the dry and the rainy periods. The bacterial abundance varied from 2.67 to 5.1 Cells10(7)mL-1 and did not show a typical temporal variation, presenting only small oscillations between the rainy and the dry periods. The bacterial biomass varied from 123 µgC L-1 to 269 µgC L-1 in the sampling sites and the average cellular volume varied from 0.12 to 0.54µm³, showing a predominance of the rods. The temperature showed a positive correlation with the cellular volume of the rods (R=0.55; p=0.02) and vibrio (R=0.53; p=0.03). Significant spatial differences of biomass (Mann Whitney: p=0.01) and cellular volume of the morphotypes (Mann Whitney: p=0.003) were found between the sampling sites. The strong positive correlations of the water temperature and oxygen with bacterioplankton showed a probable high bacterial activity in this system.

Download Full-text

Applying biomass and stem fluxes to quantify temporal and spatial fluctuations of an old-growth forest in disturbance

Biogeosciences ◽

10.5194/bg-6-1839-2009 ◽

2009 ◽

Vol 6 (9) ◽

pp. 1839-1848 ◽

Cited By ~ 1

Author(s):

S. Liu ◽

Y.-L. Li ◽

G.-Y. Zhou ◽

K. O. Wenigmann ◽

Y. Luo ◽

...

Keyword(s):

Abiotic Factors ◽

Population Fluctuations ◽

Old Growth ◽

Old Growth Forest ◽

Spatial Fluctuations ◽

Closed Canopy ◽

Average Biomass ◽

Annual Biomass ◽

Temporal And Spatial ◽

Stem Mortality

Abstract. A subtropical old-growth forest was studied over a twelve-year period to investigate temporal and spatial fluctuations of biomass and stem fluxes under disturbances. Vegetations were categorized into three types according to disturbances caused by biotic and abiotic factors, including Castanopsis chinensis population, insect direct-influenced population, and insect indirect-influenced population according to disturbance scenarios. The biomass fluxes (growth and mortality) and stem fluxes (stem recruitment and mortality) were used to quantify population fluctuations. Annual average biomass growth rate was stable throughout the study while annual biomass mortality and stem fluxes increased consistently. C. chinensis population predominantly contributed to biomass fluxes of the community. Biomass and stem mortalities of insect direct-influenced population increased significantly during the whole study period (1992–2004). Results of indirect-influenced population showed that (1) the increase in biomass of the dominant species was well correlated between different intervals. Similar relationships were found in stem fluxes; (2) higher stem mortality occurred within the DBH range of 1 to 10 cm; (3) stem fluxes in the canopy gaps were remarkably higher than those in closed canopy.

Download Full-text