scholarly journals A statistical analysis of Pi2‐band waves in the plasma sheet and their relation to magnetospheric drivers

2015 ◽  
Vol 120 (8) ◽  
pp. 6167-6175 ◽  
Author(s):  
G. Q. Wang ◽  
Y. S. Ge ◽  
T. L. Zhang ◽  
R. Nakamura ◽  
M. Volwerk ◽  
...  
2002 ◽  
Vol 20 (5) ◽  
pp. 619-628 ◽  
Author(s):  
R. T. Mist ◽  
C. J. Owen

Abstract. A statistical analysis of data from the ISEE-3 distant tail campaign is presented. We investigate the mechanism driving slow, tailward flows observed in the plasma sheet. The possibility that these slow flows are driven by mass and/or momentum transfer across the distant tail magnetopause is explored. We establish that 40% of these flows could be driven by the transfer of approximately 4% of the magnetosheath momentum flux into the magnetotail. Current understanding of the Kelvin-Helmholtz instability suggests that this figure is consistent with the amount of momentum flux transfer produced by this mechanism. We also consider the possibility that these flows are solely driven by transferring magnetosheath plasma across the magnetopause. We find that there is sufficient mass observed on these field lines for this to be the sole driving mechanism for only 27% of the observed slow flows.Key words. Magnetospheric physics (magnetotail boundary layers; plasma convection; plasma sheet)


2009 ◽  
Vol 114 (A7) ◽  
pp. n/a-n/a ◽  
Author(s):  
Y. D. Ma ◽  
J. B. Cao ◽  
R. Nakamura ◽  
T. L. Zhang ◽  
H. Reme ◽  
...  

1966 ◽  
Vol 24 ◽  
pp. 188-189
Author(s):  
T. J. Deeming

If we make a set of measurements, such as narrow-band or multicolour photo-electric measurements, which are designed to improve a scheme of classification, and in particular if they are designed to extend the number of dimensions of classification, i.e. the number of classification parameters, then some important problems of analytical procedure arise. First, it is important not to reproduce the errors of the classification scheme which we are trying to improve. Second, when trying to extend the number of dimensions of classification we have little or nothing with which to test the validity of the new parameters.Problems similar to these have occurred in other areas of scientific research (notably psychology and education) and the branch of Statistics called Multivariate Analysis has been developed to deal with them. The techniques of this subject are largely unknown to astronomers, but, if carefully applied, they should at the very least ensure that the astronomer gets the maximum amount of information out of his data and does not waste his time looking for information which is not there. More optimistically, these techniques are potentially capable of indicating the number of classification parameters necessary and giving specific formulas for computing them, as well as pinpointing those particular measurements which are most crucial for determining the classification parameters.


Author(s):  
Gianluigi Botton ◽  
Gilles L'espérance

As interest for parallel EELS spectrum imaging grows in laboratories equipped with commercial spectrometers, different approaches were used in recent years by a few research groups in the development of the technique of spectrum imaging as reported in the literature. Either by controlling, with a personal computer both the microsope and the spectrometer or using more powerful workstations interfaced to conventional multichannel analysers with commercially available programs to control the microscope and the spectrometer, spectrum images can now be obtained. Work on the limits of the technique, in terms of the quantitative performance was reported, however, by the present author where a systematic study of artifacts detection limits, statistical errors as a function of desired spatial resolution and range of chemical elements to be studied in a map was carried out The aim of the present paper is to show an application of quantitative parallel EELS spectrum imaging where statistical analysis is performed at each pixel and interpretation is carried out using criteria established from the statistical analysis and variations in composition are analyzed with the help of information retreived from t/γ maps so that artifacts are avoided.


2001 ◽  
Vol 6 (3) ◽  
pp. 187-193 ◽  
Author(s):  
John R. Nesselroade

A focus on the study of development and other kinds of changes in the whole individual has been one of the hallmarks of research by Magnusson and his colleagues. A number of different approaches emphasize this individual focus in their respective ways. This presentation focuses on intraindividual variability stemming from Cattell's P-technique factor analytic proposals, making several refinements to make it more tractable from a research design standpoint and more appropriate from a statistical analysis perspective. The associated methods make it possible to study intraindividual variability both within and between individuals. An empirical example is used to illustrate the procedure.


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