JaLCDOI 10.18926/ESR/54116
Title Alternative Application of simulated annealing to focal mechanism determination
FullText URL esr_022_1_009_023.pdf
Author Komatsu, Masanao| Takenaka, Hiroshi|
Abstract Simulated annealing (SA) is known as one of the efficient methods for global optimization. It allows for getting an optimal solution by jumping out of local minimum. In this paper, we apply the simulated annealing to determination of focal mechanism solution. To investigate the feasibility of the application, we determine focal mechanism solution of the 14 March 2014 Iyo-Nada intermediatedepth earthquake. The computation of SA method is then 1278 times faster than that of the grid search method.
Keywords focal mechanism solution
Publication Title Okayama University Earth Science Report
Published Date 2015-12-27
Volume volume22
Issue issue1
Start Page 9
End Page 23
ISSN 1340-7414
language 日本語
Copyright Holders © 2015 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved
File Version publisher
NAID 120005728632
JaLCDOI 10.18926/ESR/58574
Title Alternative Computation of non-linear site response by the time-domain finite-difference method
FullText URL esr_026_001_017.pdf
Author TORIGOE, Yusuke| KOMATSU, Masanao| TAKENAKA, Hiroshi|
Abstract We have developed a time-domain staggered-grid finite-difference code for modeling non-linear response of a one-dimensionally inhomogeneous subsurface structure to a SH plane-wave incidence. It employs the velocity-stress formulation of elastodynamic equation for the linear part, and adopts a elastoplastic rheology model for the non-linear relation between the stress and strain. In this paper, we apply this code to four constitutive models from linear-elastic to nonlinear: (1) linear elastic model, (2) linear viscoelastic model, (3) elastoplastic model, and (4) viscoelastoplastic model, which simulate shallow sand and clay structures and are vibrated by a vertically incident SH plane-wave of Ricker wavelet, to compare the linear and the non-linear soil behaviors including low strains damping (viscoelastic effect) and/or hysteretic attenuation (non-linear effect). We also apply it to a local strong-motion record of the 2000 Western-Tottori earthquake (MW6.8). We then simulate characteristics of non-linear site response such as reduction of the spectral amplitude in the high frequency band and shift of the peak frequencies to lower frequencies.
Keywords finite-difference method non-linear site response strong motion
Publication Title Okayama University Earth Science Report
Published Date 2019-12-27
Volume volume26
Issue issue1
Start Page 1
End Page 17
ISSN 1340-7414
language 日本語
Copyright Holders © 2019 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved
File Version publisher