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81.
82.
P. Bogaert D. Fasbender 《Stochastic Environmental Research and Risk Assessment (SERRA)》2007,21(6):695-709
In spite of the exponential growth in the amount of data that one may expect to provide greater modeling and predictions opportunities,
the number and diversity of sources over which this information is fragmented is growing at an even faster rate. As a consequence,
there is real need for methods that aim at reconciling them inside an epistemically sound theoretical framework. In a statistical
spatial prediction framework, classical methods are based on a multivariate approach of the problem, at the price of strong
modeling hypotheses. Though new avenues have been recently opened by focusing on the integration of uncertain data sources,
to the best of our knowledges there have been no systematic attemps to explicitly account for information redundancy through
a data fusion procedure. Starting from the simple concept of measurement errors, this paper proposes an approach for integrating
multiple information processing as a part of the prediction process itself through a Bayesian approach. A general formulation
is first proposed for deriving the prediction distribution of a continuous variable of interest at unsampled locations using
on more or less uncertain (soft) information at neighboring locations. The case of multiple information is then considered,
with a Bayesian solution to the problem of fusing multiple information that are provided as separate conditional probability
distributions. Well-known methods and results are derived as limit cases. The convenient hypothesis of conditional independence
is discussed by the light of information theory and maximum entropy principle, and a methodology is suggested for the optimal
selection of the most informative subset of information, if needed. Based on a synthetic case study, an application of the
methodology is presented and discussed. 相似文献
83.
Guo Qiliang 《中国地震研究》2007,21(3):345-354
The hydrofracturing technique has developed into a reliable and practical method for determining the original three-dimensional crustal stress state of underground caverns,the load-bearing capacity of a high pressure cavern itself,and the high pressure hydraulic permeability of rock masses,and has also been extensively used in disposal of nuclear waste,long and deeply-buried traffic channels and high-pressure cavern engineering for hydraulic power plants.The practice shows that the comprehensive measurement of the physical parameters of the rock mass and taking full use of the wall rock load-bearing capacity to optimize the engineering design hold are very useful in ensuring the engineering safety and improving the design level. 相似文献
84.
José Carlos de Araújo 《地球表面变化过程与地形》2007,32(13):2005-2018
A new equation to assess hillslope sediment production, based on physical and probabilistic approaches, is presented. The equation, which allows the computation of the delivery ratio for every event, considers the physical variables of travel distance, stream power, settling velocity and gross erosion. The probability density function that arises from the new formulation is solved using the principle of maximum entropy. Based on data from five watersheds in both tropical and temperate zones, the new delivery parameter Kv is calibrated and associated with vegetation cover and conservation practice. The proposed equation is rationally based in relation to parameter Kv. The entropy‐based equation was applied to assess sediment yield in two other experimental watersheds, showing good predictability for the set (mean absolute error of 20·8%). No systematic error was found in the analysed data. The entropy‐based equation showed good predictability for long‐term sets of data and for high‐erosivity events, but did not perform well for the low‐erosivity ones. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
85.
测量监理工作的初步探讨 总被引:3,自引:1,他引:3
本文介绍了测量监理工作的主要内容、方法,对道路、桥涵、隧道等工程测量监理工作要点进行了初步探讨。 相似文献
86.
基于MEM1谱分析的水文时间序列隐含周期特性研究 总被引:13,自引:1,他引:13
水文时间序列的隐含周期(本文将简单周期、复合周期及近似周期等统称为隐含周期)的识别、判定是一个重要而又较为困难的问题,相对成熟和有效的做法是对其进行频谱分析。建立在最大熵原理(POME)基础之上的MEM1谱分析,克服了传统谱分析方法的诸多不足,具有频谱光滑、分辨率高等独特优势。为此,以黄河花园口(秦厂)测站年径流系列、月径流系列和年最大洪峰流量序列隐含周期特性的研究为例,探讨了MEM1谱分析在水文时间序列隐含周期特性中的应用。 相似文献
87.
考虑利用卫星像片进行制图问题,对于需要两张或更多张卫片才能覆盖的地区进行连续制图时,需要研究多张卫片的图像镶嵌问题,利用二面投影原理对卫片原的镶嵌问题进行了研究,主要考虑两张相邻卫片的几何配准问题。 相似文献
88.
详细介绍了新型湿度检定箱内部气路原理及升降湿外围控制原理,并给出故障检修实例 ,供设备检定人员在维修工作中参考。 相似文献
89.
粘弹性介质中的地震波 总被引:1,自引:0,他引:1
给出了三元件的标准线性粘弹性固体在半平面内传播的地震波的解析解,它是由已知的弹性半平面内的解析解迭粘滞性解而得,从而克服了视地壳为二元件粘弹性体的Voigt模型或Maxell模型的缺点。 相似文献
90.
热带和热带外海表温度异常与低空环流特征比较 总被引:9,自引:7,他引:9
利用旋转主分量方法(RPC),在对西太平洋和印度洋1980年1月至1988年9月共105个月的月平均海表温度(SST)进行分析的基础上,提取热带模及高纬模两种SST异常(SSTA)分布。再通过分析同期850hPa,各气象要素在该两模上的投影,比较低层大气与不同纬度上SSTA相联系的异常特征。结果表明,无论是热带还是热带外地区,暖性SSTA上空均有正的水汽异常及平均流场对月平均水汽输送的异常辐合。两地区SSTA上空850hPa月平均异常的最重要差异表现在流场、高度场及温度场上。热带正SSTA上方850hPa位势高度及温度均为负距平,流场呈Gill型的气旋式异常环流。热带外正SSTA上方850hPa高度及温度均为正距平,流场则呈反气旋式异常环流。分析表明,高纬度的这种异常特征主要是由于中高纬度大气的地转性和斜压性较强所致。 相似文献