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1.
2.
Measures of Parameter Uncertainty in Geostatistical Estimation and Geostatistical Optimal Design 总被引:2,自引:2,他引:2
Wolfgang Nowak 《Mathematical Geosciences》2010,42(2):199-221
Studies of site exploration, data assimilation, or geostatistical inversion measure parameter uncertainty in order to assess
the optimality of a suggested scheme. This study reviews and discusses measures for parameter uncertainty in spatial estimation.
Most measures originate from alphabetic criteria in optimal design and were transferred to geostatistical estimation. Further
rather intuitive measures can be found in the geostatistical literature, and some new measures will be suggested in this study.
It is shown how these measures relate to the optimality alphabet and to relative entropy. Issues of physical and statistical
significance are addressed whenever they arise. Computational feasibility and efficient ways to evaluate the above measures
are discussed in this paper, and an illustrative synthetic case study is provided. A major conclusion is that the mean estimation
variance and the averaged conditional integral scale are a powerful duo for characterizing conditional parameter uncertainty,
with direct correspondence to the well-understood optimality alphabet. This study is based on cokriging generalized to uncertain
mean and trends because it is the most general representative of linear spatial estimation within the Bayesian framework.
Generalization to kriging and quasi-linear schemes is straightforward. Options for application to non-Gaussian and non-linear
problems are discussed. 相似文献
3.
K. R. Muraleedharan P. K. Dinesh Kumar S. Prasanna Kumar Sebin John B. Srijith K. Anil Kumar K. Naveen Kumar S. Gautham V. Samiksha 《Estuaries and Coasts》2018,41(4):1021-1035
Mud bank formation during the southwest monsoon along the southwest coast of India remains an enigma to the researchers and coastal community in spite of several earlier studies. The present study attempts to unravel the mystery through a high-frequency, season-long time-series observation at Alappuzha, located at the southern part of the west coast of India, a region of frequent occurrence of mud bank. Using 7-month-long weekly time-series observation, we identified strong winds and high waves associated with onset of the southwest monsoon and subsequent three episodic atmospheric low-pressure events (LPEs).With the help of in situ time-series data, we show that the strong winds and high waves associated with southwest monsoon pre-conditions the near shore bottom sediment to bring it into suspension. The high amplitude waves associated with the southwest monsoon, while propagating from the deep water to shallow water region, interact with the bottom initiating bottom-sediment movement and its suspension due to wave refraction and shoaling. The sporadic occurrence of the atmospheric LPEs enhances the process of suspension of bottom sediment in the near shore region leading to the formation of fluid mud. Simulations with a cohesive sediment transport model yielded realistic estimates of sediment transport, in the presence of an onshore current, a pre-requisite for transporting the fluid mud toward the coast. The prevailing onshore upwelling current during the southwest monsoon provides the favorable pre-requisite conditions for transporting the fluid mud through depression channel network towards the coast. Once sufficient quantity and thickness of fluid mud is accumulated in the near shore region, it acts as a wave damper for subsequent high monsoon waves, as indicated by the time-series wave data, leading to the formation of tranquil mud bank region. Depression channel networks extending from the shelf to the coast off Alappuzha, Kochi, Ponnani, Beypore, and Ullal were found in the bathymetric charts, thus explaining why mud banks occur only at few locations in spite of the prevalence of similar monsoon conditions. 相似文献
4.
5.
Expression of putative zinc-finger protein lcn61 gene in lymphocystis disease virus China (LCDV-cn) genome 总被引:1,自引:0,他引:1
An open reading frame (lcn61) of lymphocystis disease virus China (LCDV-cn), probably responsible for encoding putative zinc-finger proteins was amplified
and inserted into pET24a (+) vector. Then it expressed in E. coli BL21 (DE3), and His-tag fusion protein of high yield was obtained. It was found that the fusion protein existed in E. coli mainly as inclusion bodies. The bioinformatics analysis indicates that LCN61 is C2H2 type zinc-finger protein containing
four C2H2 zinc-finger motifs. This work provides a theory for functional research of lcn61 gene.
Supported by High Technology Research and Development Program of China (863 Program, No. 2006AA100309) 相似文献
6.
Graça Cabeçadas M. José Brogueira M. Gelena Cavaco Célia Gonçalves 《Journal of Oceanography》2010,66(2):201-210
Although the circulation of intermediate water masses in the eastern North Atlantic remains poorly defined, the presence of
fresher intermediate waters, the Sub-Artic (SAIW) and the Antarctic Intermediate Water (AAIW), as well the saline intermediate
Mediterranean Water (MW), has been tracked using biogeochemical properties. Here we assess the hydrographic and chemical structures
of intermediate waters along the western Portuguese margin by examining the vertical distributions and property-property plots
of chemical tracers (oxygen and nutrients). AAIW was traced by low oxygen and high nutrients, while SAIW was recognized by
low nutrients. The Mediterranean Water (MW) undercurrent is shown to spread towards the eastern flank of Gorringe bank. Concurrently,
the fresher waters gained salt by direct incorporation of MW, while this water was enriched in nutrients on its way northward
and westward owing, to a great extent, to the entrainment of an AAIW branch. The distributions of nutrients and apparent oxygen
utilization are discussed in terms of regional ocean circulation. Our analysis suggests a circulation pattern of the various
intermediate waters along the western Portuguese margin: MW extends all over the area, but its presence is more pronounced
around cape St. Vincent; SAIW apparently moves southward, reaching the Gorringe bank region, and AAIW flows northward along
the coast and around the bank. 相似文献
7.
Kieran P. Donaghy 《Journal of Geographical Systems》2011,13(1):17-30
In the literatures of regional science, urban economics, and urban development planning, a working assumption is that individuals
respond to incentives and regulations, given their preferences. Models for planning and policy analyses are used to consider
what might occur if the incentives or regulations were different. In these models, however, preferences are usually assumed
to be given and stable, and agents are usually assumed to be homogeneous. This paper focuses on the implications of making
preferences in models of policy implementation endogenously determined and time varying heterogeneous agents. We consider
first the recent literature on intertemporal choice and preference change, which cuts across many disciplines, and more briefly
the literature on norm-regarding behavior. We then elaborate a simple model of transportation demand—from a static to a dynamic
orientation, from fixed and exogenously given preferences of strictly self-regarding agents to endogenously determined and
policy-induced preferences of heterogeneous agents—and illustrate its characteristics with simple numerical examples. 相似文献
8.
The application of the saddlepoint approximation to reliability analysis of dynamic systems is investigated. The failure event in reliability problems is formulated as the exceedance of a single performance variable over a prescribed threshold level. The saddlepoint approximation technique provides a choice to estimate the cumulative distribution function (CDF) of the performance variable. The failure probability is obtained as the value of the complement CDF at a specif ied threshold. The method requires computing the saddlepoint from a simple algebraic equation that depends on the cumulant generating function (CGF) of the performance variable. A method for calculating the saddlepoint using random samples of the performance variable is presented. The applicable region of the saddlepoint approximation is discussed in detail. A 10-story shear building model with white noise excitation illustrates the accuracy and effi ciency of the proposed methodology. 相似文献
9.
The Ocean Drilling Program (ODP) initiated drilling at Site 1256D in the Guatemala Basin, about 1,000 km off the East Pacific
Rise to penetrate plutonic rocks, anticipated to be relatively shallow in this region, formed at an ultra-fast spreading rate.
IODP Expedition E312 successfully drilled into gabbros at ~1,150 m in basement. Multi-channel seismic traces show weak laterally
coherent sub-basement reflections at borehole depths. Synthetic reflectivity seismograms were computed using a Ricker wavelet
and impedance profiles from borehole sonic logs. These seismograms show significant sub-basement amplitude peaks. A zero-offset
vertical seismic profile, shot on E312, was processed to investigate the authenticity of these reflections and their relationship
to borehole geology. A dual scheme of the median filtering and F–K dip filtering was used. Tests with synthetic seismograms
indicate the approach is effective at reasonable SNR levels. Downgoing energy is clearly identified but negligible upgoing
energy is visible over random noise. These results indicate that lava flows and igneous contacts in upper ocean crust have
significant topography on lateral scales less than the Fresnel Zone (~300 m) due to igneous and tectonic processes. 相似文献
10.