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11.
Copula-based geostatistical modeling of continuous and discrete data including covariates 总被引:4,自引:3,他引:1
Hannes Kazianka Jürgen Pilz 《Stochastic Environmental Research and Risk Assessment (SERRA)》2010,24(5):661-673
It is common in geostatistics to use the variogram to describe the spatial dependence structure and to use kriging as the spatial prediction methodology. Both methods are sensitive to outlying observations and are strongly influenced by the marginal distribution of the underlying random field. Hence, they lead to unreliable results when applied to extreme value or multimodal data. As an alternative to traditional spatial modeling and interpolation we consider the use of copula functions. This paper extends existing copula-based geostatistical models. We show how location dependent covariates e.g. a spatial trend can be accounted for in spatial copula models. Furthermore, we introduce geostatistical copula-based models that are able to deal with random fields having discrete marginal distributions. We propose three different copula-based spatial interpolation methods. By exploiting the relationship between bivariate copulas and indicator covariances, we present indicator kriging and disjunctive kriging. As a second method we present simple kriging of the rank-transformed data. The third method is a plug-in prediction and generalizes the frequently applied trans-Gaussian kriging. Finally, we report on the results obtained for the so-called Helicopter data set which contains extreme radioactivity measurements. 相似文献
12.
13.
S. Ullah D. Bindi M. Pittore M. Pilz S. Orunbaev B. Moldobekov S. Parolai 《Bulletin of Earthquake Engineering》2013,11(2):385-399
Site response analysis plays an important role in seismic hazard and risk assessment, and in defining the optimal engineering design for civil structures. However, due to increasing urbanization, target areas are often too vast to be covered by standard approaches, resulting in large uncertainties in the spatial variability of the expected ground motion. Here, we propose a method to improve the spatial resolution of ground motion variability in terms of Standard Spectral Ratios (SSRs), using earthquakes recorded at a few selected sites for a relatively short amount of time, and seismic noise data collected over a denser grid, taking advantage of clustering and correlation analysis. The method is applied to Bishkek, Kyrgyzstan. Using the K-means clustering algorithm, three clusters of site response types have been identified, based on their similarity of SSRs. The cluster’s site responses were adopted for sites where only single station noise measurements were carried out, based on the results of correlation analysis. The spatial variability of the site response correlates well with the main geological features in the area. In particular, variability is noted from south to north, consistent with both the changes in the thickness of the sedimentary cover over the basin and in the Quaternary material outcropping at the surface. This method has therefore the potential to improve the estimation of site effects at the local scale in the future. 相似文献
14.
Statistical Classification of Different Petrographic Varieties of Aggregates by Means of Near and Mid Infrared Spectra 总被引:1,自引:0,他引:1
The increasing interest of the construction aggregates industry in reducing production costs and the costs resulting from
improper use of construction materials leads to the question whether it is possible to statistically identify some rock variants
by their reflectivity of near-infrared and mid-infrared light. Infrared spectroscopy allows quantitative and qualitative analysis
of minerals in a reliable manner, whereas the classification of rocks is complicated by the fact that the optic behavior of
minerals forming the rock often appears muted. In addition, minor constituents may dominate the spectrum. Furthermore the
relevant spectra form high dimensional data, which are extremely difficult to analyse statistically, especially when curves
are very similar. Common methods of multivariate statistics for this type of data, used in chemometric studies, followed by
linear discriminant analysis, do not lead to acceptable classification error rates. In this paper wavelets are used in order
to reduce dimensionality. As wavelets are better able to mirror local behavior of curves, they are more suitable for selecting
characteristic features. The approximation is analyzed in terms of its classification properties using Mahalanobis distance
or flexible discriminant analysis. 相似文献
15.
Asten Michael W. Yong Alan Foti Sebastiano Hayashi Koichi Martin Antony J. Stephenson William J. Cassidy John F. Coleman Jacie Nigbor Robert Castellaro Silvia Chimoto Kosuke Cornou Cécile Cho Ikuo Hayashida Takumi Hobiger Manuel Kuo Chun-Hsiang Macau Albert Mercerat E. Diego Molnar Sheri Pananont Passakorn Pilz Marco Poovarodom Nakhorn Sáez Esteban Wathelet Marc Yamanaka Hiroaki Yokoi Toshiaki Zhao Don 《Journal of Seismology》2022,26(4):757-780
Journal of Seismology - Site response is a critical consideration when assessing earthquake hazards. Site characterization is key to understanding site effects as influenced by seismic site... 相似文献
16.
G. Ameri A. Oth M. Pilz D. Bindi S. Parolai L. Luzi M. Mucciarelli G. Cultrera 《Bulletin of Earthquake Engineering》2011,9(3):717-739
We exploit S-wave spectral amplitudes from 112 aftershocks (3.0 ≤ ML ≤ 5.3) of the L’Aquila 2009 seismic sequence recorded at 23 temporary stations in the epicentral area to estimate the source
parameters of these events, the seismic attenuation characteristics and the site amplification effects at the recording sites.
The spectral attenuation curves exhibit a very fast decay in the first few kilometers that could be attributed to the large
attenuation of waves traveling trough the highly heterogeneous and fractured crust in the fault zone of the L’Aquila mainshock.
The S-waves total attenuation in the first 30 km can be parameterized by a quality factor QS(f) = 23f
0.58 obtained by fixing the geometrical spreading to 1/R. The source spectra can be satisfactorily modeled using the omega-square
model that provides stress drops between 0.3 and 60 MPa with a mean value of 3.3±2.8 MPa. The site responses show a large
variability over the study area and significant amplification peaks are visible in the frequency range from 1 to more than
10 Hz. Finally, the vertical component of the motion is amplified at a number of sites where, as a consequence, the horizontal-to-vertical
spectral ratios (HVSR) method fails in detecting the amplitude levels and in few cases the resonance frequencies. 相似文献
17.
Correction to: Microtremor array method using spatial autocorrelation analysis of Rayleigh-wave data
Hayashi Koichi Asten Michael W. Stephenson William J. Cornou Cécile Hobiger Manuel Pilz Marco Yamanaka Hiroaki 《Journal of Seismology》2022,26(4):629-629
Journal of Seismology - 相似文献
18.
Hayashi Koichi Asten Michael W. Stephenson William J. Cornou Cécile Hobiger Manuel Pilz Marco Yamanaka Hiroaki 《Journal of Seismology》2022,26(4):601-627
Journal of Seismology - Microtremor array measurements, and passive surface wave methods in general, have been increasingly used to non-invasively estimate shear-wave velocity structures for... 相似文献
19.
Bo Zhao Ling Han Jianjian Wu Lei Liu Tingting Wu Jürgen Pilz Fan Yang 《Journal of the Indian Society of Remote Sensing》2018,46(1):97-107
Based on the Landsat 8 OLI image, hydroxyl and the concomitant ferrous alterations in and around the Dexing porphyry polymetal deposit were preliminarily delineated by the fractal summation model, and the false anomalies therein unrelated to ore were successfully eliminated by the hot-spot analysis that can quantitatively reflect the clustering degree of the anomaly patches. Sequentially, the ratio vegetation index anomalies related partly to the mine exploitation were also delineated, and they closely edge the mining zones, namely the alteration anomaly patches. Finally, the field spectral survey for near-ore vegetation was conducted, and several lines of evidence showed that the ecological degradation surrounding the Dexing ore fields appears to be more severe and extensive than its counterparts miles away. A holistic remote-sensing schema for regional ore prospecting and associated environmental evaluation was put forward and we believe that the elimination of false anomalies may be more important than extraction of true anomaly in this carefully researched ore-district. 相似文献
20.
Fatal landslides in Europe 总被引:4,自引:3,他引:1
Ubydul Haque Philipp Blum Paula F. da Silva Peter Andersen Jürgen Pilz Sergey R. Chalov Jean-Philippe Malet Mateja Jemec Auflič Norina Andres Eleftheria Poyiadji Pedro C. Lamas Wenyi Zhang Igor Peshevski Halldór G. Pétursson Tayfun Kurt Nikolai Dobrev Juan Carlos García-Davalillo Matina Halkia Stefano Ferri George Gaprindashvili Johanna Engström David Keellings 《Landslides》2016,13(6):1545-1554
Landslides are a major hazard causing human and large economic losses worldwide. However, the quantification of fatalities and casualties is highly underestimated and incomplete, thus, the estimation of landslide risk is rather ambitious. Hence, a spatio-temporal distribution of deadly landslides is presented for 27 European countries over the last 20 years (1995–2014). Catastrophic landslides are widely distributed throughout Europe, however, with a great concentration in mountainous areas. In the studied period, a total of 1370 deaths and 784 injuries were reported resulting from 476 landslides. Turkey showed the highest fatalities with 335. An increasing trend of fatal landslides is observed, with a pronounced number of fatalities in the latest period from 2008 to 2014. The latter are mostly triggered by natural extreme events such as storms (i.e., heavy rainfall), earthquakes, and floods and only minor by human activities, such as mining and excavation works. Average economic loss per year in Europe is approximately 4.7 billion Euros. This study serves as baseline information for further risk mapping by integrating deadly landslide locations, local land use data, and will therefore help countries to protect human lives and property. 相似文献