I’d like to be a bear
de
Commentaires fermés sur If someone is bugging you, just eat him!
If someone is bugging you, just eat him!
de
Commentaires fermés sur The August 24, 2016 Norcia Earthquake/Le séisme de Norcia du 24 août 2016
The August 24, 2016 Norcia Earthquake/Le séisme de Norcia du 24 août 2016
Par chance, on peut raisonnablement penser que la plus grosse réplique a déjà eu lieu (M5.5, survenu 1 h environ après le choc principal).
There is every indication that the largest aftershock occurred yet (M5.5, about 1 h after the mainshock)
de
Commentaires fermés sur
Arrière les esquimaux ! Tourné à Villerville (Calvados)… 17 jours de soleil en juillet !
de
Commentaires fermés sur Moment de sagesse !
Moment de sagesse !
A l’ombre du flamboyant
“Au départ, il faut être poursuivi par la peur de la mort comme un cerf qui s’échappe d’un piège. A mi-chemin, il ne faut rien avoir à regretter, comme le paysan qui a travaillé son champ avec soin. A la fin, il faut être heureux comme quelqu’un qui a accompli une grande tâche.”
Texte du bouddhisme tibétain
de
Commentaires fermés sur Online! (Journal of South American Earth Sciences)
Online! (Journal of South American Earth Sciences)
Relocalizing a historical earthquake using recent methods: The 10 November 1935 Earthquake near Montserrat, Lesser Antilles
Peter Niemz
Institut für Geowissenschaften, Friedrich-Schiller-Universit€at Jena, Burgweg 11, 07749 Jena, Germany
Daniel Amorese
Equipe de Sismologie, Observatoire Volcanologique et Sismologique de Guadeloupe, IPGP, Sorbonne Paris Cite, UMR 7154 CNRS, Univ Paris Diderot, Le
Houelmont, 97113 Gourbeyre, La Guadeloupe, France
and Université de Caen-Normandie, 14 032 Caen Cedex, France
de
Commentaires fermés sur New breakpoint analysis of English Soccer Data
New breakpoint analysis of English Soccer Data
In geophysics, we are especially interested in investigating changes in various temporal curves. For this purpose, I developed an R function to scan and identify important breakpoints in any time series (this function is included in the R package ACA).
Here I am going to show a new analysis of changes in scoring patterns over time in English soccer. This data set is not exactly what a geophysicist would process but it is real fun and relevant to a wide audience. The previous analysis of this time series is published by James P. Curley (jc3181 AT columbia DOT edu) here
James P. Curley’s results
James P. Curley used the breakout function in the BreakoutDetection R package. The breakout algorithm is referred to as E-Divisive with Medians (EDM) and is utilizing permutation tests to assess for changes in medians between steady states. James P. Curley set to 10 the minimum number of observations between change points. As stated by JPC, The change-points identified by the BreakoutDetection package define 7 periods of time (1881-1898, 1898-1923, 1923-1933, 1933-1950, 1950-1961, 1961-1974, 1974-2013) and are probably those that we would expect.
Below are reproduced the interpretation and the plot from James P. Curley:
“The most interesting one is probably the one identified at 1923. The offside law was changed in 1925 to enable more scoring. The other revealing one is at 1974. Soccer tactics were evolving throughout the 1960s with the adoption of ‘method football’ and more focus on defense. This shift is picked up by this analysis at the 1974 breakpoint.”
The SDScan (ACA R package) results
The change-points identified by the R ACA package define 6 periods of time (1881-1896, 1896-1914, 1914-1924, 1924-1935, 1935-1967, 1967-2013). Some breakpoints are very similar to those of the BreakoutDetection library: 1896 (1898 from BreakoutDetection), 1924 (1923 from BreakoutDetection), 1935 (1933 from BreakoutDetection). The R ACA package finds an additional change-point in 1914 (it’s the beginning of WWI! ). For the points after 1935, the two methods do not perfectly agree: The R ACA package fails to detect the effect of WWII but it locates definitely sooner the last change-point (1967, whereas BreakoutDetection puts it in 1974).
With the R ACA package, the effect of the offside law (changed in 1925) is detected in 1924 and the effect of ‘method football’ (introduced in the mid-1960s) is detected as soon as 1967.
Statistics for the change-points are :
They show that the two first discontinuities (1967 and 1924) are very strong change-points (just have a look to their large DisSNR values! ).
Any questions or comments, please email me at amorese AT ipgp DOT fr
de
Commentaires fermés sur Published! (Seismological Research Letters)
Published! (Seismological Research Letters)
Automatic clustering of macroseismic intensity data
points from Internet questionnaires: Efficiency of the
Partitioning Around Medoids (PAM)
Daniel Amorese
Equipe de Sismologie, Observatoire Volcanologique et
Sismologique de Guadeloupe, IPGP, Sorbonne Paris Cité,
UMR 7154 CNRS, Univ Paris Diderot, Le Houëlmont, 97113 Gourbeyre, La Guadeloupe, France
And Université de Caen-Basse-Normandie, 14 032 Caen cedex, France
Rémy Bossu
CEA, DAM, DIF F-91297 Arpajon, France
Euro-Med Seismological Centre, France
Gilles Mazet-Roux
Euro-Med Seismological Centre, France
de
Commentaires fermés sur Varying b-values everywhere…
Varying b-values everywhere…
Une publication pertinente sur les variations du paramètre b de la loi de Gutenberg-Richter (…plus on discrétise le milieu et plus on obtient les résultats que l’on veut…) / A very relevant publication about extreme discretization:
de
Commentaires fermés sur Guadeloupe, mais Normandie aussi/Guadeloupe but also Normandy
Guadeloupe, mais Normandie aussi/Guadeloupe but also Normandy
British Normandy hit by a small earthquake:
de
Commentaires fermés sur On commence!
On commence!
Ce blog débute le 21 avril 2014.