Ejection fraction by combined inverse Fourier analysis and second-derivative technique: Correlation with isocontour method

1986 ◽  
Vol 12 (2) ◽  
pp. 69-71
Author(s):  
Suppiah Balachandran ◽  
Stuart Eason ◽  
Lynn McGuire ◽  
Suzanne Bernard ◽  
Charles Boyd
Keyword(s):  
Ejection Fraction ◽  
Fourier Analysis ◽  
Second Derivative

Comparison of the Second-derivative Critical-point Method with Fourier Analysis for Noise Removal

2014 ◽  
Vol 64 (10) ◽  
pp. 963-967
Author(s):  
Han Gyeol PARK ◽  
Tae Jung KIM* ◽  
Jun Seok BYUN ◽  
Yu Ri KANG ◽  
Young Dong KIM†
Keyword(s):  
Fourier Analysis ◽  
Critical Point ◽  
Noise Removal ◽  
Point Method ◽  
Second Derivative

The LDE-Type Flare Occurrence (1969-1993)

1994 ◽  
Vol 144 ◽  
pp. 279-282
Author(s):  
A. Antalová
Keyword(s):  
Time Series ◽  
Fourier Analysis ◽  
Sunspot Cycle ◽  
List Type ◽  
Type Number ◽  
Solar Cycles ◽  
Type Iv ◽  
Long Duration ◽  
Cycle Maximum ◽  
Flare Index

AbstractThe occurrence of LDE-type flares in the last three cycles has been investigated. The Fourier analysis spectrum was calculated for the time series of the LDE-type flare occurrence during the 20-th, the 21-st and the rising part of the 22-nd cycle. LDE-type flares (Long Duration Events in SXR) are associated with the interplanetary protons (SEP and STIP as well), energized coronal archs and radio type IV emission. Generally, in all the cycles considered, LDE-type flares mainly originated during a 6-year interval of the respective cycle (2 years before and 4 years after the sunspot cycle maximum). The following significant periodicities were found:• in the 20-th cycle: 1.4, 2.1, 2.9, 4.0, 10.7 and 54.2 of month,• in the 21-st cycle: 1.2, 1.6, 2.8, 4.9, 7.8 and 44.5 of month,• in the 22-nd cycle, till March 1992: 1.4, 1.8, 2.4, 7.2, 8.7, 11.8 and 29.1 of month,• in all interval (1969-1992):a)the longer periodicities: 232.1, 121.1 (the dominant at 10.1 of year), 80.7, 61.9 and 25.6 of month,b)the shorter periodicities: 4.7, 5.0, 6.8, 7.9, 9.1, 15.8 and 20.4 of month.Fourier analysis of the LDE-type flare index (FI) yields significant peaks at 2.3 - 2.9 months and 4.2 - 4.9 months. These short periodicities correspond remarkably in the all three last solar cycles. The larger periodicities are different in respective cycles.

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