人工育珠对三角帆蚌(Hyriopsis cumingii)遗传基因影响的初步研究

采用酚-氯仿和试剂盒两种提取法对三角帆蚌怀珠群与非怀珠群各6个个体进行基因组DNA的提取,然后在优化RAPD(随机扩增多态性DNA)检测条件基础上,从80个随机引物中筛选出12个扩增较好且多态性强的引物进行RAPD扩增,产物通过水平板琼脂糖凝胶电泳和垂直板聚丙烯酰胺凝胶电泳两种方法进行检验并对DNA的多态性进行分析。结果显示在怀珠群和非怀珠群检测到的位点数、多态位点比例、平均Shannon多态性信息指数、平均Nei's基因多样性指数、群体内个体间平均遗传相似率和平均遗传距离分别为100、33%、0.1927、0.1324、0.904、0.096,95、47.37%、0.2711、0.1879、0.861、0.139,群体间的平均遗传距离为0.821,非怀珠群的变异性大于怀珠群;本研究还获得了两群体各自的特异扩增谱带及两群体间表达差异较大谱带,这些位点很可能是由人工育珠所引起。根据MEGA4.0软件的UPGMA和NJ程序构建的分子系统树可直观地将两群体分开。     

Exploring uncertainty in remotely sensed data with parallel coordinate plots

The existence of uncertainty in classified remotely sensed data necessitates the application of enhanced techniques for identifying and visualizing the various degrees of uncertainty. This paper, therefore, applies the multidimensional graphical data analysis technique of parallel coordinate plots (PCP) to visualize the uncertainty in Landsat Thematic Mapper (TM) data classified by the Maximum Likelihood Classifier (MLC) and Fuzzy C-Means (FCM). The Landsat TM data are from the Yellow River Delta, Shandong Province, China. Image classification with MLC and FCM provides the probability vector and fuzzy membership vector of each pixel. Based on these vectors, the Shannon's entropy (S.E.) of each pixel is calculated. PCPs are then produced for each classification output. The PCP axes denote the posterior probability vector and fuzzy membership vector and two additional axes represent S.E. and the associated degree of uncertainty. The PCPs highlight the distribution of probability values of different land cover types for each pixel, and also reflect the status of pixels with different degrees of uncertainty. Brushing functionality is then added to PCP visualization in order to highlight selected pixels of interest. This not only reduces the visualization uncertainty, but also provides invaluable information on the positional and spectral characteristics of targeted pixels.     

GISVlog模型的设计与实现

本文以地理信息系统(GIS为基础,分析了地理信息系统沃客(GISVlog,)形成的两个背景——网络新技术提高GIS生命力和沃客(Vlog,Vedio log的缩写)为网络增值;分别论述了GISVlog形成对GIS发展和Vlog发展的意义;在普通GIS的系统功能结构和Vlog的系统功能结构的基础上构建GISVlog的框架结构并加以实现;论文最后展望了GISVlog的发展前景,提出GISVlog是网络搜索技术新的研究方向。     

三种验潮方法水位观测性能比较与统计分析

水尺、压力式验潮仪与验潮井验潮仪是海道测量水位控制和水位观测的主要手段。通过6日6个时间段的同步比对试验,计算了三种方法获取水位观测数据之间的潮时差和潮高差,分析了三种观测手段的水位观测性能以及产生差值的可能原因,提出了使用方法的建议。     

The determination of potential difference by the joint application of measured and synthetical gravity data: a case study in Hungary

In an elementary approach every geometrical height difference between the staff points of a levelling line should have a corresponding average g value for the determination of potential difference in the Earth’s gravity field. In practice this condition requires as many gravity data as the number of staff points if linear variation of g is assumed between them. Because of the expensive fieldwork, the necessary data should be supplied from different sources. This study proposes an alternative solution, which is proved at a test bed located in the Mecsek Mountains, Southwest Hungary, where a detailed gravity survey, as dense as the staff point density (~1 point/34 m), is available along a 4.3-km-long levelling line. In the first part of the paper the effect of point density of gravity data on the accuracy of potential difference is investigated. The average g value is simply derived from two neighbouring g measurements along the levelling line, which are incrementally decimated in the consecutive turns of processing. The results show that the error of the potential difference between the endpoints of the line exceeds 0.1 mm in terms of length unit if the sampling distance is greater than 2 km. Thereafter, a suitable method for the densification of the decimated g measurements is provided. It is based on forward gravity modelling utilising a high-resolution digital terrain model, the normal gravity and the complete Bouguer anomalies. The test shows that the error is only in the order of 10⁻³mm even if the sampling distance of g measurements is 4 km. As a component of the error sources of levelling, the ambiguity of the levelled height difference which is the Euclidean distance between the inclined equipotential surfaces is also investigated. Although its effect accumulated along the test line is almost zero, it reaches 0.15 mm in a 1-km-long intermediate section of the line.     

Non-stationary covariance function modelling in 2D least-squares collocation

Standard least-squares collocation (LSC) assumes 2D stationarity and 3D isotropy, and relies on a covariance function to account for spatial dependence in the observed data. However, the assumption that the spatial dependence is constant throughout the region of interest may sometimes be violated. Assuming a stationary covariance structure can result in over-smoothing of, e.g., the gravity field in mountains and under-smoothing in great plains. We introduce the kernel convolution method from spatial statistics for non-stationary covariance structures, and demonstrate its advantage for dealing with non-stationarity in geodetic data. We then compared stationary and non- stationary covariance functions in 2D LSC to the empirical example of gravity anomaly interpolation near the Darling Fault, Western Australia, where the field is anisotropic and non-stationary. The results with non-stationary covariance functions are better than standard LSC in terms of formal errors and cross-validation against data not used in the interpolation, demonstrating that the use of non-stationary covariance functions can improve upon standard (stationary) LSC.     

面向流媒体传输的空间数据变化累积模型

将流媒体技术引入到以矢量数据为主的网络GIS传输中,其关键是建立逐级精细化的多层次表达模型,并在服务器端数据预组织上建立线性索引结构。本研究针对该目标建立一种矢量数据多重表达的新模型,即变化累积模型,认为尺度空间中从粗到细的数据表达过程是一些"变化"的累积,"变化"表现为两个连续尺度表达间的差别,通过"变化"元素的逐渐增加或减少来实现渐进传输。基于该模型对面状数据渐进式传输进行研究,将多边形分级剖分为一系列凸壳或外接矩形的基础上建立变化累积模型,通过剖分元素的组合完成渐进式流媒体传输。     

基于SAR干涉点目标分析技术的城市地表形变监测

通过深入研究干涉点目标的相位模型,提出基于空间搜索的邻近点目标干涉相位差解缠方法,用以计算点目标的地形残差和线性形变,以及分离点目标大气延迟相位和非线性形变相位的时空域滤波方法,解决干涉点目标分析中的关键问题.最后,以苏州地区地表沉降监测为应用试验,利用形成的SAR干涉点目标形变信息提取技术,获取苏州市区1992-2002年间的地表沉降信息.研究结果与已有文献记录保持比较好的一致性,证明SAR干涉点目标技术完全可以发展成为应用于城市地表形变监测的实用化技术.

Abstract：

Interferometric point target analysis (IPTA) is one of the latest developments in radar interferometric processing. It is achieved by analysis of the interferometric phases of some individual point targets, which are discrete and present temporarily stable backscattering characteristics, in long temporal series of interferometric SAR images. This paper analyzes the interferometric phase model of point targets, and then addresses two key issues within IPTA process. Firstly, a spatial searching method is proposed to unwrap the interferometric phase difference between two neighboring point targets. The height residual error and linear deformation rate of each point target can then be calculated, when a global reference point with known height correction and deformation history is chosen. Secondly, a spatial-temporal filtering scheme is proposed to further separate the atmosphere phase and nonlinear deformation phase from the residual interferometric phase. Finally, an experiment of the developed IPTA methodology is conducted over Suzhou urban area. Totally 38 ERS-1/2 SAR scenes are analyzed, and the deformation information over 3 546 point targets in the time span of 1992-2002 are generated. The IPTA-derivecl deformation shows very good agreement with the published result, which demonstrates that the IPTA technique can be developed into an operational tool to map the ground subsidence over urban area.     

月面形貌的3维可视化算法

基于大范围地形可视化算法研究的基础上,对平面geometry clipmaps算法进行改进,利用GPU的顶点着色器实现平面地形向球面地形的投影变换,并综合利用球面视域裁剪、球面视点控制等技术,使geometry clipmaps算法适用于球面海量地形数据的3维可视化;收集处理月球全球影像和形貌高程数据,对算法进行验证,实现月球表面形貌的实时动态3维可视化.试验表明:绘制算法可不受数据量大小的限制、绘制效率高、效果逼真,但存在两极变形较大的缺点.

Abstract：

Based on the study of visualization arithmetic of large area terrain, plane geometry clipmaps algorithm is improved. Projection transformation from plane landform to sphere landform was realized by using GPU vertex shader. In that improved algorithm, methods such as sphere vision field culling and sphere viewpoint control are used.That makes geometry clipmops algorithm more effective in 3D visualization of massive sphere terrain data. The whole moon image and DEM data are collected and disposed, which are used to verify the capability of that algorithm, realizing dynamic and real time 3D visualization of moon surface. The experiments show that the graphic algorithm isn't limited by data quantity, which is of high efficiency and reality simulation, but the two-pole distortion is serious.     

基于边缘分析的海面溢油检测

提出一种基于边缘检测的快速溢油信息提取方法, 首先对溢油图像进行ROA(radio of average)边缘检测, 根据检测结果进行AOI(area of interest)提取, 然后使用改进的Weibull-CFAR检测算法对AOI进行溢油检测, 并与全局CFAR检测结果进行对比。实验结果证明, 所提出的方法对于非均匀灰度SAR图像溢油检测准确性较好、效率较高, 特别适用于大图像的快速溢油检测。