开山石填海挤淤区非均匀软弱地基的治理

对开山石填海挤淤形成的非均匀软弱地基进行处理时，由于工程性质很差、厚度较大、沉降固结历时较长且数值较大的淤泥层位于开山石回填层之下，地基处理比较困难。本文介绍了一个经济、合理的地基处理方法，对沿海地区大量存在的同类工程具有参考价值。     

中国大陆西南地区二次强震活动的信息和信息熵的分析

本文从现代统计物理学中熵的概念出发,用所定义的合成缺信量和地震活动信息熵的方法,讨论了中国西南地区永善、龙陵二次强震前后地震活动的信息和信息熵,采用时间域、空间域以及空间扫描三种不同的分析方法,结果表明,强震前缺信量的降低和信息熵的减熵过程是明显的,并且具有熵值下降过程中发震,随后熵值恢复的孕震模式。     

西秦岭白依沟群沉积环境分析

白依沟群是西秦岭地区迄今发现的最古老地层,厘定为震旦系下统,是一套浅变质水携火山碎屑岩—陆源碎屑岩建造。依据其沉积环境的差异和岩石组合,划分为上、中、下三段。通过笔者研究,认为是大陆山间河流出口处近源冲积扇体中形成的辫状河体系,为主河道—河道心滩—洪泛平原与湖泊等环境的沉积产物。     

Using exploration history to estimate undiscovered resources

Inference about deposits left to be discovered in a partially explored oil field that require only assumptions about the randomness in the exploration procedure are considered. Unbiased estimators, estimators based on partial likelihood methods and confidence procedures are proposed.     

Comments on log-quadratic relations in hydraulic geometry

A mathematical analysis of log-quadratic hydraulic geometry relations explains the association between the shapes of the depth and velocity curves, and identifies other properties of the relations. By considering the nature of resistance variation, a mathematical and physical argument is put forward to account for the particular shapes apparently adopted by these curves.     

Comparisons of two global built area land cover datasets in methods to disaggregate human population in eleven countries from the global South

ABSTRACT

Mapping built land cover at unprecedented detail has been facilitated by increasing availability of global high-resolution imagery and image processing methods. These advances in urban feature extraction and built-area detection can refine the mapping of human population densities, especially in lower income countries where rapid urbanization and changing population is accompanied by frequently out-of-date or inaccurate census data. However, in these contexts it is unclear how best to use built-area data to disaggregate areal, count-based census data. Here we tested two methods using remotely sensed, built-area land cover data to disaggregate population data. These included simple, areal weighting and more complex statistical models with other ancillary information. Outcomes were assessed across eleven countries, representing different world regions varying in population densities, types of built infrastructure, and environmental characteristics. We found that for seven of 11 countries a Random Forest-based, machine learning approach outperforms simple, binary dasymetric disaggregation into remotely-sensed built areas. For these more complex models there was little evidence to support using any single built land cover input over the rest, and in most cases using more than one built-area data product resulted in higher predictive capacity. We discuss these results and implications for future population modeling approaches.     

流体溃变与天气系统的转折性变化

简单介绍了溃变图方法,并运用溃变观点研究了天气系统的转折性变化问题。研究表明,溃变图比通常的天气图具有更为丰富的信息,尤其是非均匀和不连续信息,它对天气系统转折性变化的预测是一种更为有效的方法     

应用最大熵原理分析水利工程经济效益的风险

采用层次分析方法,将水利工程经济效益系统分为防洪、发电、灌溉效益子系统,辩识出风险因子,建立了基于最大熵原理(准则)的经济效益风险分析模型,并给出求解方法。对总系统经济效益风险分析采用了两种方法:一是直接对辩识出的风险因子进行概率分析,得出总效益指标的最大熵密度函数;二是按照"风险树"的思路,分析子系统效益的风险特性,再进行风险组合,从而考察总效益的风险性。用实例验证了该模型的可行性和实用性。     

GIS中面元的误差熵模型

根据整个线元边缘分布的平均信息熵确定了“ε－带”的宽度，提出了线元的平均误差熵带模型，进一步扩展到面元的误差熵环模型。误差熵环的带宽取构成边界线的各线段误差熵的加权平均值。最后通过算例比较了面元的误差熵环和误差环模型，绘出了它们的可视化图形，得出了一些有益的结论。