FAT32与FAT16文件系统的结构差异

详细介绍了FAT32和FATl6在数据组织结构上的差异，并着重讨论了这两个文件系统在不同数据组织结构上的功能区别和技术要点。     

城市三维地质数据管理与服务系统框架研究

城市地质数据的数字化管理与服务是“数字城市“工程的重要内容,3D GIS将在未来的城市数字化建设中扮演核心角色.介绍了3D GIS的发展现状及应用前景,详细讨论了基于3D GIS构建的城市地质数据管理与服务系统的设计思路和结构功能.三维数据结构的研究是3D GIS的核心问题并成为当前制约3D GIS深入发展与应用的瓶颈,由于缺乏对三维地质数据进行有效管理与可视化表达的三维数据模型,当前GIS的三维地质建模能力与三维空间分析能力都极为薄弱.在分析城市三维地质数据多种建模方法的基础上,采用一种基于TIN和TEN的混合数据结构来构建城市地质数据建模系统.针对城市三维地质数据的特点,探讨了城市三维地质海量数据的采集与管理、城市三维地质数据信息的Web发布等重要问题,力求为系统功能的最终实现提供完整的解决方案.     

面向信息服务的SDI数字地理空间数据框架研究

“空间数据基础设施”(SpatialDataInfrastructure,SDI)是各国信息化发展的重要支撑,随着我国信息化进程的飞速推进,电子政务、公众信息服务对SDI提出了更高的要求。数字地理空间数据框架是SDI的核心与基础,是支持地理空间信息服务的关键。本文在分析国外技术现状与趋势的基础上,提出了适合我国国情的多尺度地理空间数据框架的模型,并通过实际工程验证了该模型的合理性与可行性。     

Application of RgMap system on digital regional geological survey

Digital geological mapping fundamentally broke through the traditional working pattern, successfully carried out the geological mapping digitalization. By using the RGMAP system to field digital geological mapping, the authors summarized the method of work and the work flow of the RGMAPGIS during the field geological survey. First, we prepared material, set up the PRB gallery, then put the geographic base map under the background maplayer and organizing the field hand map, forming the field factual datum map. At last, the geological space database is formed.     

Application of RgMap system on digital regional geological survey

Digital geological mapping fundamentally broke through the traditional working pattern,successfully carried out the geological mapping digitalization.By using the RGMAP system to field digital geological mapping,the authors summarized the method of work and the work flow of the RGMAPGIS during the field geological survey.First,we prepared material,set up the PRB gallery,then put the geographic base map under the background maplayer and organizing the field hand map,forming the field factual datum map.At last,the geological space database is formed.     

基于3S技术的城市防洪管理支持系统——以深圳市防洪管理支持系统为例

本文针对城市防洪的特点,论述了基于3S(GIS-地理信息系统/RS-遥感/GPS-全球定位系统)技术的防洪管理支持系统的总体设计、体系结构设计等内容。总体设计思路采用系统工程方法,遵循“以人为本”的理念,从用户的需求出发,根据用户需求和网络化要求,按照层状结构划分为决策层、业务层、管理维护层和技术支撑层4个层次。总体结构设计包括系统功能结构设计和软件体系设计,并以深圳市防洪管理支持系统为例,介绍了提出设计思路的具体实现和应用效果。     

基于数字有机体存储系统配额机制的设计与实现

在数字有机体存储系统中,一个用户可能同时登陆多个站点,并分别在不同的登陆站点上消耗分散在不同地域的存储资源.如何管理用户配额成为亟待解决的问题.所设计和实现的配额机制将用户的配额控制分散开,能够同时处理多用户、多并发的配额请求,达到配额的异步分配的目的,并且为用户的配额信息设置了3个缺省副本,保证配额信息的可靠性.     

Complex ecologic-economic system of afforestation—An example of sustainable agriculture

The paper deals with a transformation model of a backward district into a prosperous one. The district is geographically located in Lixiahe region, Jiangsu Province. The region had long been known as one of the poorest area in China, and had been alternatively attacked by flood, waterlogging, drought, salinization, and plague of insect. Since the seventies of this oentury efforts to open up trenches on lowland and to level up the shoaly land have been made. A kind of tree, which is tolerable to high watertable, was used to afforest the land. Cereal crop, vegetable and beans are grown. In some cases, the shoaly land is used for sheep grazing and fishery. A favorable combination of forestry, agriculture, animal husbandry and fishery has been set up in the region. There are five types of managements in the system: 1) forestry-agriculture complex management, 2) forestry-fishery complex management, 3) forestry-aquatic plant-fishery complex management, 4) forestry-animal husbandry complex management, and 5) forestry-edible mushroom complex management. The principles and ecological benefits of this system can be identified: 1) Increase soil fertility by piling mud from marsh land on top soil, and thicken the arable layer. 2) Enhance the utilization rate of sunlight and energy, due to the change of microclimate in field. 3) As a result of multiple layer cultivation and multi-cropping, the production has been greatly increased. 4) Accelerate the cycling of matter and conversion of energy and nutrient of the system. 5) Decrease the consumption of soil fertility and increase the capability of controlling insect pests. 6) Improve ecological environment by afforestation. 7) Raise income and provide jobs for local peasants, even some ones from other part of this province.     

基于Oracle Spatial的空间数据库缓存的关键技术

Oracle Spatial是目前发展得比较成熟的对象关系型空间数据库存储模型,它实现了空间数据与属性数据的一体化存储,可以定义特定的数据类型,具有开放的存储格式,为GIS数据共享提供新的解决方案;但由于其采用扩展结构的空间数据库模型,对空间数据进行间接存取,数据存储和获取的效率较低。本文在阐述了扩展结构空间数据库模型的优势和局限性的基础上,提出采用缓存技术来提高数据访问效率,重点研究了空间数据库客户端缓存的关键技术,包括缓存实现机制、数据编码方法、数据一致性控制等,并给出实验对比数据,证明了空间数据缓存技术对空间数据尤其是大数据量空间数据的读取上所取得的成效。最后,本文指出了这一技术尚存在的问题及初步解决思路。     

城市燃气管道数字化管理系统方案的框架设计

根据城市燃气管道具有隐蔽性、系统性和动态性,以及点多、线长、面广等特点,考虑城市燃气管网、储配站、CNG加气站、LNG接收站、用户及运营完整性管理各方面需求,探讨数字信息化发展趋势,提出针对城市燃气管网的数字化管理系统的功能要求、总体架构、体系结构、子系统方案的框架设计及系统安全策略,并阐述数据库、项目管理及GIS等系统软件的选型,为城市燃气管道数字化管理系统建设提供参考依据.     

基于ACE的海量三维空间数据通信研究

三维可视化已成GIS发展的潮流,这必然会导致空间数据量的激增,通过集群系统和并行数据库系统可以很方便地解决海量数据的存储管理问题。但是,在海量环境下,一般数据库管理系统提供的查询接口,仍然难以满足实时三维场景可视化的速度需求。因此研究C/S模式下海量三维空间数据的高效调度成为三维GIS发展亟须突破的难点。在数据库服务器端和客户端之间加上应用服务器端,提供数据缓存、预调度等功能,减少服务器端磁盘I/O所带来的时间消耗,可以明显加速数据调度。本文系统分析了这种客户端/应用服务器端/数据服务器端模式下三维空间数据通信的难点和主要设计挑战,并针对三维GIS的数据访问特征,设计了一套能满足三维GIS实时调度的通信应用层协议。以ACE中前摄器框架为基础,结合线程池技术提出分层策略,搭建了海量三维空间数据的通信架构,它是一种面向对象的构架,可以方便地进行功能的定制和扩展。     

Dynamic Evolvement of Agricultural System and Typical Patterns of Modern Agriculture in Coastal China： A Case of Suzhou

Based on dynamic theory of system, agriculture is a complex system composed by element, structure, function and development. Firstly, this paper analyzes their connotation and relationship, which could be simply described that in virtue of element integrating and structure optimizing, agricultural system may achieve multifunctionality to meet increasingly diverse demands. As a case study of Suzhou, it concludes that Suzhou has a LP-dependence on agricultural element, and the growth extent of agricultural productivity correlates to the ratio of agricultural labor reducing rate to farmland reducing rate. Agricultural structure of Suzhou changed with time, and in the early 1980s and 2000s it was most notable. Correspondingly, agricultural function has experienced a succession process: ‘production’, ‘production-living’, and ‘production-living-ecology’. At last, based on questionnaires and interviews, some new characteristics and problems of agricultural development in coastal developed region of China have been put forward. Meanwhile, some typical patterns of modern agriculture in Suzhou which adapt to system evolving are also brought up such as export-oriented agriculture, enterprises-leading agriculture, agricultural science and technology parks, characteristic and stereoscopic agriculture, tourism and sightseeing agriculture. Foundation item: Under the auspices of National Natural Science Foundation of China (No. 40635029, No. 40771014)     

Effects of corridor networks on plant species composition and diversity in an intensive agriculture landscape

The development of modern agriculture has resulted in much homogenization of the landscape consisting of large patches of farmland,so small remnant non-crop habitats especially linear corridors play an important role in the conservation of species and the maintenance of ecosystem functions.However,little attention has been paid to the effects of corridors structural characteristics on the plant species restricted to such habitats.In this study,we selected three types of corridors including ditch,hedgerow and road,and ana-lyzed their structural characteristics.The plant species presented in these corridors were investigated,and the species diversity,abun-dance and frequency were estimated.Moreover,spatial arrangements of corridors were classified into different types to discuss whether there were significant effects of corridor network on plant distribution.The results show that three types of corridors have different ef-fects on plant species composition and diversity.The one-one combined corridor networks and total network associated by three corri-dors have more complex structural features than each single type of corridor.However,there is no strong correlation between the corri-dor networks with their plant species.We suggest that carrying out a pointed vegetation survey at corridor intersections to further test the relationships between structural features of corridor and plants is necessary.     

数字油田业务对象模型设计方法

勘探开发业务对象模型以对象服务方式支持中国石化数字油田应用软件的开发和运行.描述油田勘探开发业务对象模型的基本概念及应用模式,提出业务对象模型的设计原理,包括设计原则、设计方法和设计约束,采用基于MVC模式的自上向下与自下向上相结合的方法设计业务对象模型,给出业务对象模型的设计步骤.该方法在数字油田中多源异构数据集成与服务平台的设计中得到应用,取得较好效果.     

高新技术在高速公路工程可行性研究中的应用

本文重点论述了运用3S等高新技术对高速公路工程可行性的分析和应用实例,研究表明这是一经济有效的技术途径。     

分布式空间数据库的体系结构研究

分布式空间数据库的体系结构一直是理论研究的热点和工程实践必须面对的问题。本文分析了目前分布式空间数据库体系结构的特点,然后提出了基于3层构架的分布式空间数据库体系结构。这3层分别是：本地空间数据模型层、统一的空间元数据模型层和统一的全局空间数据模型层。这种体系结构充分利用已有的成熟技术和优点。最后作者把这种体系结构用于广东省水资源规划信息管理系统,用于管理分布式的水资源规划信息。     

农业产业化信息网络系统及农产品营销网页制作研究

以蔬菜为例，建立农业产、供、销信息网络服务系统，并以金堂县主导农产品为对象试作电子商务网页，以供该县在新一轮农业产业化结构调整中应用。     

交流数字伺服系统的智能PID控制律研究

智能PID是在结合传统的PID控制和人工智能的基础上形成的，针对交流伺服系统的要求，提出智能PID控制算法，旨在提高系统控制的精度，并从理论上对控制律进行了详细地分析。然后，在Matlab的环境下进行了系统仿真实验，从结果来看，控制策略用于交流伺服系统，能够得到一个较好的系统动、静态性能，从而获得一个较好的控制品质。     

电子政务与数字中国地理空间基础框架

在对电子政务和数字中国地理空间基础框架的基本概念、内容和体系结构进行深入描述之后,指出电子政务非常需要数字中国地理空间基础框架的支撑,集中体现为：数字中国地理空间基础框架是电子政务的空间定位平台,可以为电子政务提供空间辅助决策支持,并可为电子政务提供清晰易读的可视化工具;与此同时,电子政务为数字中国地理空间基础框架的建设提供了新的应用空间和发展机遇。     

基于数字水印的电子印章系统的研究与实现

讨论了法院信息系统中的电子文档安全性问题.针对传统印章的易伪造性弊端,通过将密码签名原理和数字水印技术应用于电子印章之中,并结合COM插件技术实现了机密文档的防篡改功能、身份认证功能及不可否认性功能.