重要性权值的驾车导航POI表达规则

在导航电子地图中,针对驾车任务的POI自适应表达是提高导航电子地图信息传输效率的关键。针对这一问题,提出了基于重要性权值的驾车导航POI表达规则。首先,分析了POI重要性权值的影响因素;其次,从影响因素出发,研究了基于权值的POI规则表达的各规则项;最后,设计了POI自适应表达规则库,并在嵌入了数据处理规则库的绘图软件上进行了技术实现。试验结果表明,利用基于权值的POI表达规则进行地图表达,可以提高地图内容的层次性与清晰性,优化驾车导航服务。     

农村土地承包经营权确权登记颁证的实践与探索

土地是人类赖以生存和发展的物质基础。真实、准确的土地所有权数据是国家进行宏观经济调控的基础和重要依据。本文以广东省韶关市某村为试点,介绍了农村土地承包经营权确权登记的技术路线和工作流程,探讨了权属调查及数据库建设的方法。     

基于UML模型的空间数据库可视化建模

针对传统数据库模式在建立庞大、多维、关系复杂的地理数据库模型的过程中存在语义表达不清等问题,本文研究了空间数据库模型在传统建模软件中的构建规律,设计了空间数据库模型在UML图中的表达方式及模板库和在XML文件中的存储规则,实现了将XML文件导入GIS数据库后自动生成控件数据库模型。通过在原型系统中的应用,表明了本文建模方法具有可扩展、方便修改、建模可视化的优点。     

Performance optimization of grid aggregation in spatial data warehouses

The problem of storage and querying of large volumes of spatial grids is an issue to solve. In this paper, we propose a method to optimize queries to aggregate raster grids stored in databases. In our approach, we propose to estimate the exact result rather than calculate the exact result. This approach reduces query execution time. One advantage of our method is that it does not require implementing or modifying functionalities of database management systems. Our approach is based on a new data structure and a specific model of SQL queries. Our work is applied here to relational data warehouses.     

新区地籍数据库建设的探索与创新

地籍数据库建设工作是现代地籍管理工作的基础,在实际工作中已形成一套成熟的技术路线和数据标准.近年城市建设范围的迅速扩展对土地管理工作提出高要求,而地籍管理工作是土地管理的基础,所以地籍数据库的建设必须紧跟新区建设的步伐.在实际工作中老城区地籍数据库的建设方法并不适合在新区使用,为了提高新区地籍数据库建设工作的效率,本文对该工作进行了探索与创新.     

Characterisation of geotechnical model uncertainty

The calculated response from a numerical model will deviate from the measured one given the presence of modelling idealizations and real world construction effects. This deviation can be directly captured by a ratio between the measured and the calculated quantity. The ratio is also called a model factor in many design guides. The probabilistic distribution of the model factor is arguably the most common and simplest complete representation of model uncertainty. The characterisation of model uncertainty is identified as one of the critical elements in a geotechnical reliability-based design process in Annex D of ISO 2394:2015 “General Principles on Reliability of Structures”. This Spotlight paper reviews the databases for various geo-structures and determines their associated model statistics. Foundation load test databases are the most prevalent. A recent effort to compile a large generic database (PILE/2739) that contains 2739 field load tests conducted on various piles and installed in different soils and countries, is highlighted. This systematic compilation of load test data is part of a broader research agenda to digitalise foundation design for “precision construction”, which is targeted at characterising “site-specific” model factors and soil parameters based on both site-specific and generic data for further customisation of design to a particular site. The mean and COV of the model factor for a range of geo-structures, geomaterials, and limit states (both ultimate and serviceability) are summarized in a form suitable for adoption in design and codes of practice. Based on this summary, it is proposed that a model factor for a design model can be classified as: (1) moderately conservative (1?≤?mean?相似文献   

A computational procedure for joining separate map sheets

Map sheets have been often used as a basic spatial unit for managing spatial data produced from paper maps. This often results in incompatibility between adjacent map sheets, because spatial objects do not cross the boundaries smoothly and even the boundaries themselves do not match their neighbors exactly. To solve the problem this paper proposes a computational procedure for joining separate map sheets to obtain seamless spatial data. Line objects digitized separately in different map sheets are considered, which are frequently used to represent road networks, gas pipelines, and boundaries of polygon objects. The procedure consists of three steps: (1) extraction of end nodes, (2) detection of matching nodes, and (3) transformation of the map sheet. Each step goes interactively so that unexpected errors can be avoided by human observation. To test the validity of the procedure, map sheets are combined containing the road network data of Tokyo 23-ku area, Japan. This revised version was published online in July 2006 with corrections to the Cover Date.     

国际标准物质数据库COMAR及有证标准物质

有证标准物质（CRMs）是具有准确量值的测量标准,在分析方法研究和评价、定性和定量分析、矿产勘查、仲裁检验、质量监督检验等领域发挥着重要的作用。20世纪80年代成立的国际标准物质数据库（COMAR）是目前国际上最大的CRMs数据库,收录来自25个成员国274个生产机构提供的CRMs数量超过10200种。本文从CRMs的数量、分类、发展变化等角度全面评述了国际数据库COMAR,阐述了欧盟组织、美国、中国、日本、澳大利亚等成员国的标准物质研究情况。英、美、法、德等国家的标准物质研究开展较早,研究水平高,处于世界领先地位;中国、日本等亚洲国家标准物质的发展虽起步晚,但发展迅速,已成为向COMAR提供CRMs最多的两个国家,分别为1194种和1456种（截至2013年8月）。COMAR建立以来,工业、有色金属和物理特性三大传统应用领域的CRMs占COMA数据库总CRMs的份额一直较大,比例始终保持50%以上,其中工业领域的CRMs数量最多,占19%;有机、生物与临床类CRMs所占份额最少,仅为7%和3%。随着社会需求的增加,生物与临床、生活质量领域标准物质成为未来标准物质发展的热点方向。本文指出,未来标准物质的发展将由过去的钢铁、有色金属、物理特性等传统领域逐渐转向食品安全、环境保护、气候变化、临床医学、制药产业、生物能源等新兴领域,标准物质的研究制备、定值及不确定度将面临新的技术挑战。     

工程勘察信息系统的简单实现

随着城市建设的迅速发展，各个勘察单位积累了大量的工程资料，怎样有效的保持和利用这些资料成了一个迫切的问题。文章根据个人开发工程勘察信息系统的经历，介绍了利用VB6、Server和Matlab开发工程勘察信息系统的步骤和方法。     

高放废物处置库预选场地地学信息库的建立

本文以高放废物处置库预选场地甘肃北山玉门镇地学信息库的建立为例,详细阐述了地理信息系统在高放废物地质处置中的应用,并在此基础上分析了其应用前景,为不同层次的管理、科研人员提供了全新思路;介绍了将地理信息系统技术引入图件和资料管理的优点。