scholarly journals Creepex as a parameter of seismo-geodynamic studies based on geo-information systems

2021 ◽  
Author(s):  
A.V. Mikheeva ◽  
I.I. Kalinnikov
Keyword(s):  
Statistical Approach ◽  
Maximum Amplitude ◽  
Temporal Analysis ◽  
Geographical Information ◽  
Geoinformation Systems ◽  
World Average ◽  
Relative Contribution ◽  
The World ◽  
Focal Zone ◽  
Spatial Temporal Analysis

The GIS-EEDB (the Expert Earthquake Database) and GIS-ENDDB (the Earth’s Natural Disasters DataBase) geoinformation systems implement methods for spatial-temporal analysis of both classical and new characteristics of the seismogeodynamic process. One of the new characteristics is a normalized creepex parameter that can be used in the statistical approach to studying of seismicity to assess a relative contribution of “soft” (creep) and “hard” (explosion) movements to the overall process of focal radiation. In this paper, the following modifications of the creepex parameter are proposed and compared: 1) Cr0 Cr0_world and CrN CrN world as the result of reducing the parameters Cr0 and CrN of each event to the world average values of the creepex, obtained from the polynomial dependence of Cri_world (i = 0, N) on MS_world where Cri_world are calculated based on the world average estimates of Ms_world and mb_world at uniform intervals of the seismic moment (NEIC catalog), 2) Cr_bji as the result of reducing CrN of each event to CrN_bji i.e. to the average for the studied in this work BJI catalog creepex values obtained from the polygonal trend CrN (MS) of all the catalog events. The advantage of using the creepex parameter, reduced to the trend of averaging the magnitudes of the catalog in question, is revealed, since the smallest linear dependence of the creepex on the magnitude is achieved (in comparison with the classical and normalized creepex) and the symmetry in the maximum amplitude of the deviation of the parameter relative to zero is preserved. Examples of the application of the compared parameters in specific seismic-geodynamic studies of aftershock processes of the Molucca and Simushir earthquakes also demonstrate the advantage of the parameter Cr_bji n the observed correspondence of the variations of the latter to the known physical processes in the focal zone of the Kashmir event, studied by the seismic-geodynamic methods of the GIS-EEDB geographical information system.

scholarly journals Country transition index based on hierarchical clustering to predict next COVID-19 waves

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ricardo A. Rios ◽  
Tatiane Nogueira ◽  
Danilo B. Coimbra ◽  
Tiago J. S. Lopes ◽  
Ajith Abraham ◽  
...  
Keyword(s):  
Hierarchical Clustering ◽  
Temporal Analysis ◽  
Systems Science ◽  
Collateral Damage ◽  
Science And Engineering ◽  
University Center ◽  
Main Challenge ◽  
Johns Hopkins University ◽  
The World ◽  
Transition Index

AbstractCOVID-19 has widely spread around the world, impacting the health systems of several countries in addition to the collateral damage that societies will face in the next years. Although the comparison between countries is essential for controlling this disease, the main challenge is the fact of countries are not simultaneously affected by the virus. Therefore, from the COVID-19 dataset by the Johns Hopkins University Center for Systems Science and Engineering, we present a temporal analysis on the number of new cases and deaths among countries using artificial intelligence. Our approach incrementally models the cases using a hierarchical clustering that emphasizes country transitions between infection groups over time. Then, one can compare the current situation of a country against others that have already faced previous waves. By using our approach, we designed a transition index to estimate the most probable countries’ movements between infectious groups to predict next wave trends. We draw two important conclusions: (1) we show the historical infection path taken by specific countries and emphasize changing points that occur when countries move between clusters with small, medium, or large number of cases; (2) we estimate new waves for specific countries using the transition index.

scholarly journals A Study of "Spread?F" Ionospheric Echoes at Night at Brisbane. III. Frequency Spreading

1957 ◽  
Vol 10 (1) ◽  
pp. 60 ◽  
Author(s):  
DG Singleton
Keyword(s):  
Fine Structure ◽  
World Wide ◽  
Recent Literature ◽  
Temporal Analysis ◽  
Seasonal Distribution ◽  
The World ◽  
Diurnal Distribution ◽  
The Hours ◽  
Spread F ◽  
Pronounced Peak

Virtual range versus frequency (P'f) records of the ionosphere made at Brisbane (lat. 27�5 �S., long. 152�9 �E.) during 1952 and 1953 have been examined. It is found that occasionally neither the o nor the x mode of propagation penetrates the F2 layer at a unique frequency, the upward sweeping traces either being blurred out over a range of penetration frequencies (diffuseness) or possessing a fine structure (penetration-frequency multiplicity). Temporal analysis of the occurrence of these. effects reveals that they occur only at night; penetration-frequency multiplicity appearing more frequently in the hours before dawn, while the diurnal distribution of diffuseness has a maximum between 0100 and 0500 hr in summer and represents a more even distribution between 2100 and 0500 hr in winter. The seasonal distribution has a pronounced peak in the winter months and minima in the equinoctial months. These data are compared with the world-wide picture of these variations as it has emerged from the recent literature.

Spatial-Temporal Analysis of Mortality Using Splines

Biometrics ◽  
1995 ◽  
Vol 51 (4) ◽  
pp. 1352 ◽  
Author(s):  
A. van der Linde ◽  
K.-H. Witzko ◽  
K.-H. Jockel
Keyword(s):  
Temporal Analysis ◽  
Spatial Temporal Analysis
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