基于GML的移动GIS空间数据融合模型

文章分析了数据融合的的概念,结合GML技术,提出了基于GML的移动GIS空间数据融合模型的目标,给出并分析了该模型的体系结构,并以“请求MobileGML格式的长江大学校园地图”为例,说明了该模型的工作原理。     

GML应用建模方法的新思路

GML语言是开放地理信息系统联合会制定的基于XML的空间数据编码规范,对于GIS互操作的研究有重要的参考价值．本文首先介绍了GML语言的特点及应用,然后探讨了从建立UML模型开始,自动生成GML模式的一种可能的建模方法．     

基于GML的WebGIS的多源异构空间数据集成研究

本文阐述了目前多源异构空间数据集成的研究动向,介绍了可扩展标记语言XML和地理标记语言GML及其在WebGIS中应用的优势,提出了基于GML的WebGIS多源异构空间数据集成系统的解决方案.     

基于GML的GIS空间要素描述与应用研究

以房屋土地地理信息系统 (GIS)中的地籍图形数据为例 ,探讨了基于地理标识语言 (GML)规范的空间要素描述 ,包括其数据描述结构和GML文档 ,并基于JAVA语言、文档对象模型和XML语言接口协议 (SAX)实现了一个基于GML的地籍GIS查询系统 ,验证了提出的基于GML规范的GIS空间数据描述的可行性     

扩展XML查询实现GML查询

GML(地理标记语言)是基于XML发展而来的行业标记语言,具有XML的所有特征,同时还具有XML没有的空间特征.目前,对XML的查询有比较成熟查询规范—Xquery,扩展XML查询是实现GML查询的最佳途径,在分析现有开放源码XML查询引擎的基础上,选择XQEngine进行扩展,实现了对GML空间数据的本原查询.     

GML空间数据在Oracle XML DB 11g中的存储机制研究

GML数据的存储研究还属于一个崭新的领域,目前还没有一个比较完好的技术实现方法。在分析比较Oracle XML DB存储模式的基础上,考虑GML空间数据的特点,研究GML空间数据在Ora-cle中的存储机制,并分析储存模式的优劣。利用Oracle XML DB实现对GML数据的存储是GIS空间数据管理方面研究的一条新的思路和途径。     

GML空间数据在0racle XML DB11g中的存储机制研究

GML数据的存储研究还属于一个崭新的领域,目前还没有一个比较完好的技术实现方法.在分析比较OracleXMLDB存储模式的基础上,考虑GML空间数据的特点,研究GML空间数据在Oracle中的存储机制,并分析储存模式的优劣.利用Oracle XML DB实现对GML数据的存储是GIs空间数据管理方面研究的一条新的思路和途径.     

基于地理标识语言的空间数据查询模式与实现

提出了基于地理标识语言（GML）的地籍和房产空间对象模型，并以此探讨了基于可扩展标识语言（XML）的地籍空间对象及其关系的查询模式，给出了基于XQuery的查询实现方法．开发了一个采用JAVA、文档对象模型（DOM）、简单应用程序接口（SAX）和XQuery的空间数据管理应用平台，验证了本文提出的基于GML的空间对象模型和基于XQuery实现查询XML地籍空间数据与空间关系的可行性．     

OGSA-DAI的异源空间数据访问技术及应用

采用开放式网格服务体系结构-数据访问与集成(OGSA-DAI)中间件的数据访问模式,利用空间数据引擎的空间数据管理能力,构建分布式的多源网格数据服务(GDS).基于WKT(Well Known Text)中间数据模型,构建一个空间数据查询和访问的统一模式,并将结果集转换为通用的空间数据格式.实例表明,通过WKT中间数据模型,可实现自定义查询或跨数据服务资源的联合查询,查询结果可以方便地转换为XML,SVG,GML文档.     

基于GML的空间数据动态集成及应用研究

在分析GML数据格式和几何特征基础上,提出一个基于GML的空间数据动态集成框架,探讨了数据动态集成过程,并以福建省漳浦县绥安镇的林业数据为样本,进行了动态集成应用示范.结果表明,应用GML对空间数据进行动态集成,是在现有网络环境下以矢量方式进行数据传输、交换、集成海量空间数据最有效的方法.     

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.     

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.     

A computer generator for randomly layered structures

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

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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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。     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

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