The Bayesian bridge between simple and universal kriging   总被引：1，自引：0，他引：1  

Henning Omre  Kjetil B. Halvorsen 《Mathematical Geology》1989,21(7):767-786

Kriging techniques are suited well for evaluation of continuous, spatial phenomena. Bayesian statistics are characterized by using prior qualified guesses on the model parameters. By merging kriging techniques and Bayesian theory, prior guesses may be used in a spatial setting. Partial knowledge of model parameters defines a continuum of models between what is named simple and universal kriging in geostatistical terminology. The Bayesian approach to kriging is developed and discussed, and a case study concerning depth conversion of seismic reflection times is presented.  相似文献   

Bayesian kriging—Merging observations and qualified guesses in kriging     

Henning Omre 《Mathematical Geosciences》1987,19(1):25-39

Frequently a user wants to merge general knowledge of the regionalized variable under study with available observations. Introduction of fake observations is the usual way of doing this. Bayesian kriging allows the user to specify a qualified guess, associated with uncertainty, for the expected surface. The method will provide predictions which are based on both observations and this qualified guess.  相似文献   

Health in the Arctic and climate change     

Henning Sloth Pedersen 《Polar research》2007,26(2):104-106

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Directionally dependent strength and dilatancy behavior of soil–structure interfaces     

Stutz  Hans Henning  Martinez  Alejandro 《Acta Geotechnica》2021,16(9):2805-2820

Acta Geotechnica - Soil–structure interfaces typically exhibit a shear behavior that is independent of the direction of relative displacement due to symmetry in the solid material's...  相似文献   

Estimation of a non-stationary prior covariance from seismic data     

Rasmus Bødker Madsen  Thomas Mejer Hansen  Henning Omre 《Geophysical Prospecting》2020,68(2):393-410

Non-stationarity in statistical properties of the subsurface is often ignored. In a classical linear Bayesian inversion setting of seismic data, the prior distribution of physical parameters is often assumed to be stationary. Here we propose a new method of handling non-stationarity in the variance of physical parameters in seismic data. We propose to infer the model variance prior to inversion using maximum likelihood estimators in a sliding window approach. A traditional, and a localized shrinkage estimator is defined for inferring the prior model variance. The estimators are assessed in a synthetic base case with heterogeneous variance of the acoustic impedance in a zero-offset seismic cross section. Subsequently, this data is inverted for acoustic impedance using a non-stationary model set up with the inferred variances. Results indicate that prediction as well as posterior resolution is greatly improved using the non-stationary model compared with a common prior model with stationary variance. The localized shrinkage predictor is shown to be slightly more robust than the traditional estimator in terms of amplitude differences in the variance of acoustic impedance and size of local neighbourhood. Finally, we apply the methodology to a real data set from the North Sea basin. Inversion results show a more realistic posterior model than using a conventional approach with stationary variance.  相似文献   

Influence of molecular outflows from young stellar objects on molecular clouds     

TH. Henning 《Astronomische Nachrichten》1989,310(5):363-366

In this paper it is investigated whether molecular outflows can support the turbulence in molecular clouds against decay. In the momentum-driven regime of molecular flows the time scale of the replenishment of the fluctuations is longer than the dissipation time scale of pure hydrodynamical supersonic turbulence.  相似文献   

Correction of precipitation based on off-site weather information     

Peter Allerup  Henning Madsen  Flemming Vejen 《Atmospheric Research》2000,53(4)

Owing to aerodynamic errors, correction of precipitation measurements, liquid, mixed or solid, is often carried out by means of an explicit mathematical statistical model. The magnitude of correction, e.g., calculated as a correction factor to the observed amount of precipitation, is the dependent variable, and wind speed, temperature and a measure of precipitation intensity are independent variables entering the correction model. Usually these independent variables are accessible on site where the precipitation measurements are recorded. However, in many standard precipitation networks the gauge measurements are not accompanied by on site information of these variables, and information from remote stations must be used. The aim of the paper is to describe how the statistical models can be used in evaluating if the set of remote information of the independent variables can be used for the estimation of a reliable correction factor on site. The technique is then applied to an example of precipitation network in Denmark where the typical situation for the standard gauges is that only the amount of precipitation is available. It is expected that not only can the methods be adapted to other countries, but for landscapes similar to Denmark even the conclusions can be applied directly: extrapolation of all independent variables from remote sites should be conducted with caution, wind speed information can be extrapolated from remote sites not farther away than approximately 50 km, while information on rain intensity and temperature can be safely extrapolated across longer distances.  相似文献   

Guy P. Brasseur, John J. Orlando, and Geoffrey S. Tyndall (eds): Atmospheric Chemistry and Global Change     

Henning Rodhe 《Journal of Atmospheric Chemistry》2000,36(1):107-108

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Maribo—A new CM fall from Denmark     

Henning HAACK  Thomas GRAU  Addi BISCHOFF  Marian HORSTMANN  John WASSON  Anton SØRENSEN  Matthias LAUBENSTEIN  Ulrich OTT  Herbert PALME  Marko GELLISSEN  Richard C. GREENWOOD  Victoria K. PEARSON  Ian A. FRANCHI  Zelimir GABELICA  Philippe SCHMITT‐KOPPLIN 《Meteoritics & planetary science》2012,47(1):30-50

Abstract– Maribo is a new Danish CM chondrite, which fell on January 17, 2009, at 19:08:28 CET. The fall was observed by many eye witnesses and recorded by a surveillance camera, an all sky camera, a few seismic stations, and by meteor radar observatories in Germany. A single fragment of Maribo with a dry weight of 25.8 g was found on March 4, 2009. The coarse‐grained components in Maribo include chondrules, fine‐grained olivine aggregates, large isolated lithic clasts, metals, and mineral fragments (often olivine), and rare Ca,Al‐rich inclusions. The components are typically rimmed by fine‐grained dust mantles. The matrix includes abundant dust rimmed fragments of tochilinite with a layered, fishbone‐like texture, tochilinite–cronstedtite intergrowths, sulfides, metals, and carbonates often intergrown with tochilinite. The oxygen isotopic composition: (δ¹⁷O = ?1.27‰; δ¹⁸O = 4.96‰; Δ¹⁷O = ?3.85‰) plots at the edge of the CM field, close to the CCAM line. The very low Δ¹⁷O and the presence of unaltered components suggest that Maribo is among the least altered CM chondrites. The bulk chemistry of Maribo is typical of CM chondrites. Trapped noble gases are similar in abundance and isotopic composition to other CM chondrites, stepwise heating data indicating the presence of gas components hosted by presolar diamond and silicon carbide. The organics in Maribo include components also seen in Murchison as well as nitrogen‐rich components unique to Maribo.  相似文献   

Anmeldelser     

Henning Mørch  Torben Birch-Thomsen  Sofus Christiansen  Katharine Cough 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(2):111-114

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