基于影子显示位图技术的GIS图形部分的实现

在地理信息系统的开发过程中,对屏幕图形进行精确识别是一个较难解决的技术问题．在某些实际应用中,近似处理的误差已经超过了人们所能接受的程度．该文就地理信息系统中的图形识别技术提出了一种全新的方法——影子显示位图（shadow display bitmap）技术．影子显示位图技术用于精确地识别显示在屏幕上的各种简单的和复杂的图形元素．该文论述了影子显示位图技术的工作原理和实现方法,通过实验证明影子显示位图技术解决了识别图形元素时的误差问题,识别复杂图形元素的能力强,比常用图形识别技术容易实现．     

AutoCAD二次开发中实体的生成

介绍了AutoCAD二次开发生成图形实体的几种方法，脚本文件编制方法，DXF文件描述图形实体的特点，以及AutoLISP语言command函数，entmake函数，entget函数等用于生成图形实体的方法和特点．总结了AutoCAD二次开发过程中自定义函数的编制方法，包括画线函数、画矩形函数的编制方法；从高级语言、数据的输入输出、界面设计等方面讨论了接口程序在生成图形实体方面的方法、技巧．     

屏幕图形的压缩存贮与释放及其在机构动态模拟中的应用

由于常规的动态模拟方法的模拟效果受到图形复杂性的严格限制，通常只用于简单图形的动态模拟．本文介绍的屏幕图形的压缩存贮与释放显示方式与图形的复杂程度无关或关系甚微，对复杂图形也能产生极为逼真的动画效果．文章论述了屏幕图形的压缩存贮与释放的实现原理及对于不同图形适配器如ＣＧＡ、ＥＧＡ／ＶＧＡ的程序设计方法，并用Ｃ语言编制了相应的子程序．通过对增程式游梁抽油机主体机构的动态模拟，介绍了其应用及程序编制的技巧．本方法不仅在机构ＣＡＤ、ＣＡＩ及其他动画技术中能发挥重要作用，而且能在图形系统的开发中得到很好的应用，其程序具有很好的移值性．     

一种静态RAM双帧存结构的图形系统及应用

针对高速图形显示系统的应用要求，设计了一种采用静态RAM的双帧存结构的高速图形显示系统，双帧存的逻辑控制和显示控制器由FPGA实现，基于该系统的双帧存结构，提出了一种实现图形叠加的新方法，该方法通过两幅图形数据分别写入不同帧存的方式，实现两幅图形的叠加．进一步提出了一种实现复杂图形分割成两部分分别生成显示的方法，该方法使图形处理器的图形处理性能加倍．     

OLE技术在MIS中的应用

跟踪分析生成图形应用程序Ｇｅｎｇｒａｐｈ中的更新图形对象子功能Ｕｐｄａｔｅｇｒｐｈ，给出在ＭＩＳ中用Ｕｐｄａｔｅｇｒａｐｈ增加图形功能的方法．该方法具有方便用户操作、提高系统安全性和系统效率等优点．     

形状及纹理分析方法在图形学中的应用研究

从图像、图形融合的思想出发,介绍了基于图像分析的表面形状恢复及纹理三维特征获取方法,并将其应用于图形建模和纹理映射．首先利用不同视点下的遮挡边缘序列,并结合其它视觉信息的分析,获取了表面点的三维几何坐标,实现了基于图像分析的表面形状绘制．接着利用阴影分析方法,提取纹理图像的表面起伏特征,将该特征结合像素点的颜色属性,进行图形纹理映射,实现了基于图像特征分析的图形纹理生成．实验结果证明了图像、图形融合思路的可行性和有效性及图像、图形融合方法的巨大潜力．     

基于CVIDraw的卡通动漫制作平台

智能可视定制平台（Intelligent Visual Customized Drawing，CVIDraw）是中山大学开发的具有自主知识产权的图形、动画及聪明图形定制工具．该系统提供了独具特色的聪明图形的变形及定制方法．使得用户无需编程即可通过对控制点的简单操控而获得丰富的图形造型。在CVIDraw的基础上开发的卡通人物定制平台——CVICartoon．主要致力于卡通漫画人物创作．同时涵盖一些基本的动漫场景绘制。     

地学图形数据的四叉树处理方法研究

介绍了地学图形数据的四叉树编码数据结构．用该数据结构研究地学图形数据的四叉树编码的转换、缩放、存贮等算法,并探讨了二维图形由四叉树编码数据结构转换为光栅显示器显示图形的方法．同时讨论了用Ｃ语言实现地学图形四叉树数据结构的各种算法．本算法适用于二维地学图形的四叉树编码数据的运压缩存贮及各种逻辑图象操作,可节省大量的存贮空间,加快图形／图象数据的运算速度,为计算机图形学的压缩编码技术提供了一种新的研究手段．     

点绘制技术在图形绘制中的应用

在基于点的图形绘制技术中，作为绘制基本元素的是点．点绘制是传统的基于三角网格绘制的重要补充．文章介绍了基于点绘制技术的原理和比较有代表性的点绘制方法，探讨了外形非常复杂的不规则几何体在计算机图形绘制中生成的物体表面空洞的处理方法．     

斜角坐标系专题地图量化信息可视化研究

信息可视化是提高专题地图展现力的重要手段．笔者引入斜角坐标系量化图形作为专题地图的表示方法,介绍了斜角坐标系图形的数学基础和展现方法,并抽象出一个基础菱形,由基础菱形组合构成各种组合图形．同时基于GIS软件Maplnfo的MapBasic宏语言,设计了基础菱形标准过程,开发出具有单、双和多坐标系绘图功能的专题地图制图模块,并能进行图形排序和图形移动,实现了量化信息的斜角坐标系图形可视化,扩展了专题地图表现形式,最后以河北省1980-1998年间的一、二、三产业数据绘图进行实证．     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.