scholarly journals A scheme for finding the front boundary of an interplanetary magnetic cloud

2009 ◽  
Vol 27 (3) ◽  
pp. 1295-1311 ◽  
Author(s):  
R. P. Lepping ◽  
T. W. Narock ◽  
C.-C. Wu
Keyword(s):  
Visual Inspection ◽  
Magnetic Cloud ◽  
Temperature Drop ◽  
Statistical Testing ◽  
Wind Data ◽  
Uncertainty Interval ◽  
Front Boundary ◽  
Estimation Scheme ◽  
Physical Quantities ◽  
Significant Proton

Abstract. We develop a scheme for finding a "refined" front boundary-time (tB*) of an interplanetary magnetic cloud (MC) based on criteria that depend on the possible existence of any one or more of four specific solar wind features. The features that the program looks for, within ±2 h (i.e., the initial uncertainty interval) of a preliminarily estimated front boundary time, are: (1) a sufficiently large directional discontinuity in the interplanetary magnetic field (IMF), (2) a significant proton plasma beta (βP) drop, (3) a significant proton temperature drop, and (4) a marked increase in the IMF's intensity. Also we examine to see if the "MC-side" of the boundary has a MC-like value of βP. The scheme was tested using 5, 10, 15, and 20 min averages of the relevant physical quantities from WIND data, in order to find the optimum average to use. The 5 min average, initially based on analysis of N=26 carefully chosen MCs, turned out to be marginally the best average to use for our purposes. Other criteria, besides the four described above, such as the existence of a magnetic hole, plasma speed change, and/or field fluctuation level change, were examined and dismissed as not reliable enough, or usually associated with physical quantities that change too slowly around the boundary to be useful. The preliminarily estimated front boundary time, tB, and its initial ±2-h uncertainty interval are determined by either an automatic MC identification scheme or by visual inspection. The boundary-scheme was developed specifically for aiding in forecasting the strength and timing of a geomagnetic storm due to the passage of a MC in real-time, but can be used in post ground-data collection for imposing consistency when choosing front boundaries of MCs. This scheme has been extensively tested, first using 81 bona fide MCs, collected over about 8.6 years of WIND data (at 1 AU), and also by using 122 MC-like structures as defined by Lepping et al. (2005) over about the same period. Final statistical testing of the 81 MCs to see how close the refined boundary-time tB* lies with respect to a preliminary time tB(VI) was carried out, i.e., to find Δt1=(tB*–tB(VI)), for the full set of MCs, where tB(VI) is usually a very accurate time previously determined from visual inspection, This testing showed that 59 Δt1s (i.e., 73%) lie within ±30 min, 71 Δt1s (i.e., 88%) lie within ±45 min, and only 5 cases lie outside a |Δt1| of 1.0 h, which is only 6% of the full 81, and these 6% would be considered unsatisfactory. Since MC parameter fitting is usually done on the basis of 30 or 60 min averages, these results seem quite satisfactory. The program for this front boundary estimation scheme is located at the Website: http://wind.nasa.gov/mc/boundary.php.

scholarly journals A slow mode transition region adjoining the front boundary of a magnetic cloud as a relic of a convected solar wind feature: Observations and MHD simulation

2008 ◽  
Vol 113 (A9) ◽  
pp. n/a-n/a ◽  
Author(s):  
Charles J. Farrugia ◽  
Nikolai V. Erkaev ◽  
Ulrich Taubenschuss ◽  
Vladimir A. Shaidurov ◽  
Charles W. Smith ◽  
...  
Keyword(s):  
Solar Wind ◽  
Transition Region ◽  
Magnetic Cloud ◽  
Mode Transition ◽  
Slow Mode ◽  
Mhd Simulation ◽  
Front Boundary

scholarly journals JASP (Software)

2020 ◽  
Author(s):  
Hyemin Han ◽  
Kelsie J Dawson
Keyword(s):  
Visual Inspection ◽  
Data Science ◽  
Meta Analysis ◽  
American Psychological Association ◽  
Statistical Testing ◽  
Analysis Program ◽  
American Psychological ◽  
Analysis Methods ◽  
Data Editor ◽  
Statistical Analysis Program

JASP, Jeffrey’s Amazing Statistics Program (official webpage: https://jasp-stats.org/), version 0.12.2, is an open-source, free statistical software package available on Windows, MacOS, and Linux platforms. It was developed by a group of quantitative methodologists who are interested in improving statistical testing and analysis methods used in the fields of psychological sciences. It implements various analysis methods, particularly those in Bayesian analysis and data science. The implemented methods include t-tests, ANOVA, regression analysis, factor analysis, machine learning, meta-analysis, network analysis, and SEM. JASP also includes a data editor for visual inspection and pre-processing. It supports data importing and exporting from/to various data sources. The statistical analysis program R constitutes the basis of JASP, but for users who are not familiar with programming, JASP is featured with a graphical user interface (GUI) so that the users can select analysis modules and modify options conveniently. To support users in academia, especially those in psychology, JASP provides functionalities for visualizing analysis results in tables and figures according to the American Psychological Association (APA) convention and presents options for modification once they are created.

scholarly journals Comparison of magnetic field observations of an average magnetic cloud with a simple force free model: the importance of field compression and expansion

2007 ◽  
Vol 25 (12) ◽  
pp. 2641-2648 ◽  
Author(s):  
R. P. Lepping ◽  
T. W. Narock ◽  
H. Chen
Keyword(s):  
Magnetic Field ◽  
Magnetic Cloud ◽  
Solar Wind Plasma ◽  
Field Observations ◽  
Average Value ◽  
Cylindrically Symmetric ◽  
Front Boundary ◽  
Free Model ◽  
Compression And Expansion ◽  
The Difference

Abstract. We investigate the ability of the cylindrically symmetric force-free magnetic cloud (MC) fitting model of Lepping et al. (1990) to faithfully reproduce actual magnetic field observations by examining two quantities: (1) a difference angle, called β, i.e., the angle between the direction of the observed magnetic field (Bobs) and the derived force free model field (Bmod) and (2) the difference in magnitudes between the observed and modeled fields, i.e., ΔB(=|Bobs|−|Bmod|), and a normalized ΔB (i.e., ΔB/<B>) is also examined, all for a judiciously chosen set of 50 WIND interplanetary MCs, based on quality considerations. These three quantities are developed as a percent of MC duration and averaged over this set of MCs to obtain average profiles. It is found that, although and its normalize version are significantly enhanced (from a broad central average value) early in an average MC (and to a lesser extent also late in the MC), the angle is small (less than 8°) and approximately constant all throughout the MC. The field intensity enhancements are due mainly to interaction of the MC with the surrounding solar wind plasma causing field compression at front and rear. For example, for a typical MC, ΔB/ is: 0.21±0.27 very early in the MC, −0.11±0.10 at the center (and −0.085±0.12 averaged over the full "central region," i.e., for 30% to 80% of duration), and 0.05±0.29 very late in the MC, showing a double sign change as we travel from front to center to back, in the MC. When individual MCs are examined we find that over 80% of them possess field enhancements within several to many hours of the front boundary, but only about 30% show such enhancements at their rear portions. The enhancement of the MC's front field is also due to MC expansion, but this is usually a lesser effect compared to compression. It is expected that this compression is manifested as significant distortion to the MC's cross-section from the ideal circle, first suggested by Crooker et al. (1990), into a more elliptical/oval shape, as some global MC studies seem to confirm (e.g., Riley and Crooker, 2004) and apparently also as confirmed for local studies of MCs (e.g., Hidalgo et al., 2002; Nieves-Chinchilla et al., 2005).

Effect of alternate feedback strategies on performance for a synthetic aircraft visual inspection task

2003 ◽  
Author(s):  
Rahul R. Desai ◽  
Anand K. Gramopadhye ◽  
Brian J. Melloy ◽  
Andrew Duchowski
Keyword(s):  
Visual Inspection ◽  
Feedback Strategies ◽  
Inspection Task

Hubungan Religiusitas dengan Citra Tubuh pada Wanita Dewasa Awal

2018 ◽  
Vol 1 (1) ◽  
pp. 9-28
Author(s):  
Dessy Sumanty ◽  
Deden Sudirman ◽  
Diah Puspasari
Keyword(s):  
Body Image ◽  
Correlation Coefficient ◽  
Research Design ◽  
Calculation Result ◽  
The Body ◽  
Statistical Testing ◽  
P Value ◽  
Significance Level ◽  
Correlational Research

This research attempts to relate the body image phenomenon with the level of subject religiosity. This research used correlational research design that was involving 332 respondents. The statistical testing which is used to test the hypothesis Rank Spearman. The calculation result with the significance level of trust 95% (a = 0.05) show that the correlation coefficient is 0.083 and p-value is 0.129. It means that Ho is accepted and H1 is rejected. It can be concluded that there is no relationship between religiosity with body image.

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