1,720,971 research outputs found
Windowed Etas Models With Application To The Chilean Seismic Catalogs
No full textThe seismicity in Chile is estimated using an ETAS (Epidemic Type Aftershock sequences) space-time point process through a semi-parametric technique to account for the estimation of parametric and nonparametric components simultaneously. The two
components account for triggered and background seismicity respectively, and are estimated by alternating a ML estimation for the
parametric part and a forward predictive likelihood technique for the nonparametric one. Given the geographic and seismological
characteristics of Chile, the sensitivity of the technique with respect to dierent geographical areas is examined in overlapping
successive windows with varying latitude. A different behaviour of background and triggered seismicity in the different windows
is observed and analyzed
Multi-fractal cancer risk assessment
No full textFrom fractal point of view, there exist two types of cancer tissues. Those having multifractal (or fractal) structure, and the rest, for example, Wilms tumors. To support the diagnostics, we shall be aware of this differentiation and we shall use robust methods for measuring of multifractality. The main reason a robust discrimination is needed is the simple fact that histopathological discrimination between mastopathy and cancer is difficult in many cases. As we show in this article, using spectra or energy for multifractal model can be of help. However, it needs robustness since many mastopathic tissues are mimicking cancer ones. This article tackles this multidisciplinary topic. In particular, we provide diffusion model for metabolic heat for both cancer and mastopathy related tissues and novel concept of metabolism related energy
Space-Time Forecasting of Seismic Events in Chile.
Get PDFThe aim of this work is to study the seismicity in Chile using the ETAS (epidemic type
aftershock sequences) space‐time approach. The proposed ETAS model is estimated
using a semi‐parametric technique taking into account the parametric and nonparametric
components corresponding to the triggered and background seismicity, respectively. The
model is then used to predict the temporal and spatial intensity of events for some areas
of Chile where recent large earthquakes (with magnitude greater than 8.0 M) occurred
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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