基于光谱知识库对高光谱影像目标快速识别方法

针对国内引进的机载高光谱成像仪（CASI/SASI）数据采集系统,介绍了利用先验知识建立的多种地物目标光谱库,以及高光谱影像目标快速识别的技术方法研究;同时还阐述了其数据处理流程、目标识别原理和应用开源代码编程实现过程,并对其结果与应用进行了简要的分析。     

三维无缝工程地质建模系统的研制

在边界表示法的基础上,提出了无缝工程地质模型的概念,实现了基于模型线框架的无缝工程地质建模方法,研制了无缝建模系统（ROCKModel）。该系统包括3个部分：原始数据转换工具、实体建模工具与辅助工具,涉及剖分、插值、曲面求交等8个基本功能模块。在基本功能模块的基础上,提出并实现了形态复杂曲面的创建、构建模型线框架、界面编辑与重构、块体搜索、岩体质量三维分级等关键技术。该系统能够实现复杂地质对象与工程对象的无缝建模与可视化,并为数值模拟软件直接提供几何模型。     

离散光滑插值方法在地球物理位场中的快速实现

研究并探讨了1种新的插值方法-离散光滑插值方法及其在地球物理位场中的快速实现.首先由待插值点与已知点之间的拓扑关系建立线性约束,进一步结合位场满足Laplace方程,建立离散光滑插值联立方程组,采用预条件共轭梯度求解该方程组.为更好地提高计算效率,在求解过程中采用螺旋坐标系和Wilson-Burg谱分解,将二维数据转换到一维空间处理.通过理论模型和实际资料计算,该方法适合地球物理位场特征,插值效果好,速度快.     

Remote Sensing Study of Gold Biogeochemical Effects in the Western Guangdong-Hainan Region1—A Case Study of the Hetai Gold Deposit

Abstract The vegetation has been poisoned by gold in the western Guangdong-Hainan region. The gold content of the leaves there is as high as 10-1961 times the abundance, the chlorophyll content is 10%-30% lower than that of the vegetation in metamorphic terrains and 10%-20% higher than that in granite terrains, and the carotenoid content is 10%-44% lower than the background value. The water content of leaves is 10% to 20% lower than the background value. The cells of leaves are deformed and broken. The leaf surface shows colour spots and becomes yellow or dark green. The spectral reflectance of the leaf surface is 5%-30% higher than the background value; the spectral shape has shifted 5-15 nm to the short wavelength. The gray scales of eanopy on images of Landsat TM and airborne imaging scanner (AIS) are 10%-100% higher than the background values. On Landsat TM and AIS false colour images, plants poisoned by gold display a yellow color, which disinguishes them from background plants. According to the spectral and image features of gold biogeochemical effects, the author has constructed a gold information system and expert prediction system, and thus two gold target areas and two gold prospect areas have been identified rapidly, economically and accurately in the western Guangdong-Hainan region which is extensively covered by vegetation.     

NASVD方法在航空伽玛能谱数据降噪中的应用

介绍了一种基于多元统计分析的降噪处理方法——NASVD方法的核心思想及其程序实现步骤。对某地区航空伽玛能谱测量数据集进行降噪处理的试验结果表明：NASVD方法能够显著地消除原始能谱数据中统计涨落的影响,其降噪效果明显优于传统的能谱降噪方法。     

The “susceptibility factor” in the atmospheric response to periodic forcing

Evidence is presented of a periodic component in the inter-annual variability of precipitation and pressure data for India during June, the month of the onset of the Indian southwest monsoon. Two frequencies that explain a statistically significant percent of the variance in these data sets are the same as the two that explain most of the variance of the average monthly lunar tidal potential for June. Not only are the frequencies the same but they are also in phase which strongly suggests that lunar tides in the atmosphere do, in fact, produce an element of climatic variability. The amplitude of the atmospheric response to this periodic forcing was not constant in time but was found to be related to the long term change in northern hemispheric surface temperature. This susceptibility of the atmosphere to an external forcing results in a nonlinear relationship between forcing and response. As a result, nonlinear regression had to be used in order to adequately define the magnitude of the response at a given frequency. The ramifications of this nonlinear response are discussed. The nonlinear interaction of the northern hemisphere temperature and the 18.6 year lunar nodal cycle results in a modulation of the frequency which appears in a linear spectral analysis near 22 years. Thus, the 22-year cycle often found in meteorological data sets may instead be the result of the modulated nodal cycle.     

时～频转换的时间范围和时间步长研究

基于均匀导电大地和可极化大地表面,电偶源电场的时间谱在无随机干扰和有随机干扰时,用不同的时间区段和时间步长进行频谱的计算结果,作者在研究了时间谱电阻率（ＴＳＲ）法的数据解释中,将时间谱转换到频率域（简称为时～频转换）时,所需要的时间范围和时间步长。     

Simulation of cyclones using synthetic data

A number of sensitivity experiments have been conducted to investigate the influence of using synthetic data on cyclone forecasts by a global spectral model. Some well known vortices have been used and the generated wind and pressure profiles are compared. It is found that the Rankine vortex and Holland’s vortex show the best representation of cyclonic circulation. Hence these two vortices are used in the sensitivity studies to simulate two cyclones, one of May 1979 and the other of August 1979. For this purpose the FGGE level-III b data set, produced at ECM WF, UK is used. Synthetic temperature and humidity data are also introduced to make the cyclones more realistic. With the use of Holland’s vortex the system is found to move faster than with the Rankine vortex. Also, the tracks of the cyclones simulated with Rankine vortex are found to be on the left side of the observed track while that of Holland’s vortex is on the right side of the observed track. However, substantial filling up of the systems are noticed with introduction of diabatic initialization of the mass and velocity fields and the forecasts of both the vortices behave differently. It is suggested that proper selection of synthetic vortex, initialization scheme and resolution of the model are very important for better forecast of cyclones.     

Developing support structures for ethnic minorities in Slovakia

Ethnic minorities are facing increasing problems of social exclusion in Central and Eastern Europe. The complex nature of the transition from socialism means that the institutional framework to support them is still being established. Whilst non-governmental organisations (NGOs) have a crucial role to play in promoting a more inclusive society, through improving access to local democratic structures for otherwise excluded groups and acting as fora for improved community participation throughout the region, their development remains fraught with problems. Examination of the experiences of one such organisation, ETNO Agentura based in northern Slovakia, provides an insight into the problems and opportunities arising as community representatives work together to provide social support for ethnic minorities. The paper outlines key issues arising from the case of ETNO Agentura, including difficulty in gaining access to supporting finance and securing long term financial viability, the lack of institutional capacity of local authorities to become receptive to their views, and implicit socio-cultural barriers to ethnic minority representation in community participation processes. Developing a fuller understanding of these problems and the measures required to overcome them is a central part of establishing a more effective role for NGOs within post socialist societies. This revised version was published online in July 2006 with corrections to the Cover Date.     

Formulation of discontinuous deformation analysis (DDA) — an implicit discrete element model for block systems

Continuum-based numerical methods have played a leading role in the numerical solution of problems in rock mechanics and engineering geology. However, for fractured rocks, a continuum assumption often leads to difficult parameters to define and over-simplified geometry to be realistic. In such case, discrete representations of fractures and individual blocks must be adopted. In this paper, a newly emerged member in the family of discrete element methods (DEM), the discontinuous deformation analysis (DDA), is presented, including its variational principle, governing equations, solution techniques and contact representation and detection algorithms. Its relative advantages and shortcomings are compared with the explicit distinct element method and the finite element method. An example of the analysis of tunnel stability is provided to demonstrate the capability of this new method.