专项气象服务经济效益的评价理论与技术

当前，由于缺乏对气象服务投入量与产出量准确而完整的统计，要对气象服务的各种经济效益作出总体评价是困难的。然而，在专项气象服务中，却不乏原始、完整而准确的资料。作者从此出发，讨论了专项气象服务经济效益评价的理论。并通过实地调查，以彭州市气象局几项专项气象服务为例探讨了评价技术。     

用样条函数计算结果研究冲绳海槽热源机制

对冲绳海槽１９８４－１９９０年的实测热流值，利用数字滤波方法计算，得到反映该区深部地壳热状态的区域热流值为８０－１６０ｍＷ／ｍ＾２，用Ｂ样条函数法对其作数值模拟，计算出海槽地温场模式，并以此研究冲绳海槽海底高热流的形成机制，得出冲绳海槽热流值的区域性变化与綦中地质构造格局呈正相关，高热流是该区现代构造活动所致，其明显特征是地壳减薄，地幔上拱等结论。     

Uncertainty as the overlap of alternate conditional distributions

An important task in modern geostatistics is the assessment and quantification of resource and reserve uncertainty. This uncertainty is valuable support information for many management decisions. Uncertainty at specific locations and uncertainty in the global resource is of interest. There are many different methods to build models of uncertainty, including Kriging, Cokriging, and Inverse Distance. Each method leads to different results. A method is proposed to combine local uncertainties predicted by different models to obtain a combined measure of uncertainty that combines good features of each alternative. The new estimator is the overlap of alternate conditional distributions.     

Reservoir description using dynamic parameterisation selection with a combined stochastic and gradient search

There is a correspondence between flow in a reservoir and large scale permeability trends. This correspondence can be derived by constraining reservoir models using observed production data. One of the challenges in deriving the permeability distribution of a field using production data involves determination of the scale of resolution of the permeability. The Adaptive Multiscale Estimation (AME) seeks to overcome the problems related to choosing the resolution of the permeability field by a dynamic parameterisation selection. The standard AME uses a gradient algorithm in solving several optimisation problems with increasing permeability resolution. This paper presents a hybrid algorithm which combines a gradient search and a stochastic algorithm to improve the robustness of the dynamic parameterisation selection. At low dimension, we use the stochastic algorithm to generate several optimised models. We use information from all these produced models to find new optimal refinements, and start out new optimisations with several unequally suggested parameterisations. At higher dimensions we change to a gradient-type optimiser, where the initial solution is chosen from the ensemble of models suggested by the stochastic algorithm. The selection is based on a predefined criterion. We demonstrate the robustness of the hybrid algorithm on sample synthetic cases, which most of them were considered insolvable using the standard AME algorithm.     

线性向量半参数模型与标量半参数模型最小二乘估计的比较

研究了最小二乘准则下线性向量半参数模型的核估计、近邻估计及样条估计3种估计方法,分析了向量半参数模型与标量半参数模型在这几种估计方法中的差异。     

用曲面Spline方法表示1900～1936年中国(部分地区)地磁场及其长期变化的分布

根据19360年426个地磁测点和28个IGRF计算的地磁数据,计算地磁场和地磁异常场各个分量的曲面Spline模型,并绘制相应的地磁图和地磁异常图.依据我国部分地区的1909～1915,1915～1920,1920～1930,1930～1936年间地磁偏角长期变化图,1908～1917,1917～1922,1922～1936年间水平强度长期变化图和1908～1922,1922～1936年间垂直强度长期变化图,使用曲面Spline方法,分别计算上述9个时间段的磁偏角（D）、水平强度（H）和垂直强度（Z）长期变化的曲面Spline模型,并绘制相应的长期变化图.根据这些长期变化模型,将19360年426个点的三分量绝对值数据归算至1940,1930,1920,1910年和1900年,从而为计算这5个年代的地磁场模型奠定了坚实的基础.     

电法勘探在常德市松散孔隙含水层中涌水量预测的应用

常德市水文地质及电测深、电测井的资料反映了孔隙水含水层涌水量的大小与含水层厚度、颗粒组分及其结构的多因素的复杂组合──—厚度（Ｍ）与视电阻率（ρ＿ｓ）的乘积密切相关，据此可预测单井涌水量。     

Archaeomagnetic secular variation in the UK during the past 4000 years and its application to archaeomagnetic dating

This paper examines the limitations and deficiencies of the current British archaeomagnetic calibration curve and applies several mathematical approaches in an attempt to produce an improved secular variation curve for the UK for use in archaeomagnetic dating. The dataset compiled is the most complete available in the UK, incorporating published results, PhD theses and unpublished laboratory reports. It comprises 620 archaeomagnetic (directional) data and 238 direct observations of the geomagnetic field, and includes all relevant information available about the site, the archaeomagnetic direction and the archaeological age. A thorough examination of the data was performed to assess their quality and reliability. Various techniques were employed in order to use the data to construct a secular variation (SV) record: moving window with averaging and median, as well as Bayesian statistical modelling. The SV reference curve obtained for the past 4000 years is very similar to that from France, most differences occurring during the early medieval period (or Dark Ages). Two examples of dating of archaeological structures, medieval and pre-Roman, are presented based on the new SV curve for the UK and the implications for archaeomagnetic dating are discussed.     

Maximum-likelihood ambiguity resolution based on Bayesian principle

 Based on the Bayesian principle and the fact that GPS carrier-phase ambiguities are integers, the posterior distribution of the ambiguities and the position parameters is derived. This is then used to derive the maximum posterior likelihood solution of the ambiguities. The accuracy of the integer ambiguity solution and the position parameters is also studied according to the posterior distribution. It is found that the accuracy of the integer solution depends not only on the variance of the corresponding float ambiguity solution but also on its values. Received: 27 July 1999 / Accepted: 22 November 2000     

第一类算子方程的吉洪诺夫正则解的收敛性和渐近阶估计

本文对于第一类算子方程当右端近似给定和当算子与右端皆近似分别给定时,讨论如何确定正则参数。并给出吉洪诺夫正则解的收敛性和渐近阶估计。