虚拟加工环境中的工件动态建模方法研究

提出并实现了基于平面纹理映射的基元立方体构造方法，以之为动态结点建立了动态八叉树结构，实现了支持变精度动态建模的自相似递归算法。该算法确保离正在加工的部位更近的区域有更高的精度，并采用C^ Builder和OpenGL构造了一个集成于虚拟加工环境的可加工工件模型。     

A Linear Programming Approach to Determine the Normative Composition of Sedimentary Rocks

The analysis of modal and normative composition of sedimentary rocks is widely used for studying their sources and tectonic settings. The normative calculation of the mineral composition of rocks in this study is formulated as a linear programming problem and is solved by means of the simplex method. This enables both simultaneous and successive subtraction of a set of basic minerals from a rock sample represented by its chemical composition {SiO₂...LOI}. Such an approach provides a more exact calculation of the contribution of basic minerals in the rock. This mathematical approach is used to study two representative sets of sandstones and fine-grained rocks from a Meso- to Neoproterozoic marginal basin of southeastern Siberia (Uchur–Maya region, Yakutia) and a Pennsylvanian-Lower Permian uplifted continental block in Colorado, USA. The calculated normative mineral compositions of the Siberian sandstones are consistent with the observed modal compositions. These sandstones vary from K- Feldspar rich arkoses at the base of the sequence (the Uchur Group, lower Riphean) to quartz arenites or lithic sandstones and wacke in transgressive successions of the middle-upper Riphean. Arkoses and quartz arenites are dominant in Meso- to Neoproterozoic Siberia. These samples represent craton interior uplifted basement and quartzose, recycled orogen provenance of a stable craton in Rodinia. There are higher but consistent discrepancies between the calculated and observed compositions for the Pennsylvanian to Lower-Permian arkoses and quartz arenites (Sangre de Cristo, Belden, and Maroon Formations). The differences between the predicted and observed mineralogy may be due to uncertainties in the modes in the matrix and cement of the sandstones. This normative program should supplement modal calculations and provide better genetic constructions, especially in case of matrix-rich sandstones.     

Smoothing and Change Point Detection for Gamma Ray Count Data

Gamma ray detectors are used to measure the natural radioactivity of rocks. For a number of boreholes drilled at a site the gamma ray detector is lowered into each borehole and counts of gamma ray emissions at different depths are recorded as the instrument is gradually raised to ground level. The profile of gamma counts can be informative about the geology at each location. The raw count data are highly variable, and in this paper we describe the use of adaptive smoothing techniques and change point models in order to identify changes in the geology based on the gamma logs. We formulate all our models for the data in the framework of the class of generalized linear models, and describe computational methods for Bayesian inference and model selection for generalized linear models that improve on existing techniques. Application is made to gamma ray data from the Castelreagh Waste Management Centre which served as a hazardous waste disposal facility for the Sydney region between March 1974 and August 1998. Understanding the geological structure of this site is important for further modelling the transport of pollutants beneath the waste disposal area.     

磁共振用于医学成像与地面找水方法的技术对比研究

目的 医学核磁共振与地面核磁共振找水是核磁共振技术应用的不同领域。本文通过对二者在方法原理、技术、应用等方面的对比研究，提出了地面核磁共振找水工作建议。     

声波测试中振子衰减的线列阵模型

从声波在岩体中传播产生衰减的基本原理出发，建立了声波衰减振子的线列阵模型。该模型是将传播声波路径的岩体分为若干个振子，从波动概念出发，以振动原理作依据建立波动方程．为探讨岩体声波衰减机制提供了一种新的研究方法，把振动和波动直观地联系起来．单一方向上有限点的声波测试技术有可能被多方向的声测技术所代替．该模型的建立，使模态分析和参数识别方法应用到岩体声波测试技术中成为可能。     

高耸塔架结构节点损伤基于神经网络的两步诊断法

本文针对高耸钢塔架结构的损伤特点，建立了具有节点损伤的有限元模型，提出了一种分层神经网络两步诊断法：第一步，由基于区域残余力理论的第一层神经网络进行结构损伤区域的初诊；第二步，由基于应变模态理论的第二层神经网络进行损伤区域内的具体损伤节点位置和程度的诊断。对一平面塔架结构的数值仿真分析表明：本文提出的损伤诊断方法的结果是令人满意的。     

基于灵敏度分析的结构损伤识别中的传感器优化配置

本文提出了结构损伤识别中的传感器测点优化配置的方法。该方法是通过仅考虑结构刚度变化的结构特征灵敏度分析，以结构各自由度的损伤信息为条件，计算出结构的Fisher信息阵，并且考虑到Fisher信息阵的逆阵可能不存在，而将Fisher信息阵对应于每个自由度进行分解，通过计算每个分解的Fisher信息阵的迹而确定每个自由度含有的损伤信息的多少，从而从结构的全部自由度中去掉那些含损伤信息少的自由度。建立直接利用结构不完整的实测模态来定位结构的损伤，避免结构模态扩阶带来不必要的误差。最后，通过数值算例表明，该方法能有效地识别出结构的损伤。     

非线性编辑与线性编辑在气象电视节目中的使用

通过对非线性编辑与线性编辑两者的概念及其特点、优势的介绍,指出在气象电视节目的后期制作中,怎样恰当地选择使用非线性编辑、线性编辑或二者同时使用。     

截渗墙(防渗墙)质量检测技术研究进展

截渗墙是堤坝整治的重要手段，但由于截渗墙施工质量不易控制，并且具有隐蔽性等特点，截渗墙的质量检测非常重要且存在不小的难度。本文首先简要介绍了近年来得到研究与实践的一些截渗墙质量检测技术，并对各种检测技术的特点进行了分析，最后推荐了截渗墙(防渗墙)质量检测的技术方案。     

非线性模型线性近似的容许曲率

由于不同的非线性模型具有不同的非线性强度，使得一些非线性模型可以线性近似，而另一些则不能。本文介绍度量非线性强度的方法，提出判断非线性模型能否线性近似的数值标准——容许曲率