基于控制规则的地图符号化技术研究     

李少梅  孙群  刘海砚  周炤 《测绘学院学报》2009,(2)

在数字地图符号化过程中,普遍存在着同一种地理要素由于其某一属性项取值的不同而采用不同的地图符号进行符号化的情况。另外,由于数字地图中没有记录说明注记的位置、字体、颜色、方式等相关信息,因此说明注记在符号化过程中缺乏定位和显示的相关依据。为了灵活、有效地解决上述问题,总结并提出了地图符号化控制规则,通过对控制规则的解释来实现数字地图的符号化。这种地图符号化技术已在实际应用中取得预期的效果,证明了其可行性。  相似文献   

关联规则挖掘在卷烟市场研究中的应用     

黄智  何跃 《成都信息工程学院学报》2005,20(3):319-322

应用基于Apriori算法的关联规则挖掘技术对一次卷烟市场调查得到的数据进行分析，找出其中的关联规则，作为正确决策的基础。  相似文献   

主动式地理信息服务质量(QoAGIS)评估研究   总被引：2，自引：0，他引：2  

黄全义  朱海国  钟少波  郭际明 《测绘学报》2009,38(6)

设计主动式地理信息服务质量(quolily of active geospatial information service,QoAGIS)评估系统,阐述主动式地理信息服务的内涵及其逻辑结构,提出AGIS质量评估指标的概念,并对其中的本征质量指标与广义质量指标的定量化实现进行研究,给出综合评估指标.最后,通过实验表明QoAGIS评估系统的适应性和可靠性.

Abstract：

Currently, the passive aspects of geospatial information service (GIS) and the unpredictability of QoGIS are unable to meet the applications in some deeper fields. A new evaluation system of quality of active geospatial information service (QoAGIS) is presented. The connotation and logical structure of AGIS is analyzed, in which it advanced basic event and its expression, event operation's methods, the expression of complex event and the driven rules, the indices of QoAGIS evaluation are presented, in which the intrinsic quality index and the generalized quality index are researched on. Finally the compositive evaluation index is calculated. The QoAGIS evaluation system has been used in an application of AGIS, the experiment indicated its adaptation and reliability.  相似文献   

Methods for ultimate limit state assessment of ships and ship-shaped offshore structures: Part I—Unstiffened plates     

Jeom Kee Paik  Bong Ju Kim  Jung Kwan Seo 《Ocean Engineering》2008,35(2):261-270

The present paper is Part I of a series of three papers prepared by the authors on the methods useful for ultimate limit state assessment of marine structures, that have been developed in the literature during the last few decades. It is considered that such methods are now mature enough to enter day-by-day design and strength assessment practice. The aims of the three papers are to conduct some benchmark studies of such methods on ultimate limit state assessment of (unstiffened) plates, stiffened panels, and hull girders of ships and ship-shaped offshore structures, using some candidate methods such as ANSYS nonlinear finite element analysis (FEA), DNV PULS, ALPS/ULSAP, ALPS/HULL, and IACS common structural rules (CSR) methods. As an illustrative example, an AFRAMAX-class hypothetical double hull oil tanker structure designed by CSR method is studied. In the present paper (Part I), the ultimate limit state assessment of unstiffened plates under combined biaxial compression and lateral pressure loads is emphasized using ANSYS, DNV PULS, and ALPS/ULSAP methods, and their resulting computations are compared. Part II will deal with methods for the ultimate limit state assessment of stiffened panels under combined biaxial compression and lateral pressure using ANSYS, DNV PULS, and ALPS/ULSAP methods, and Part III will treat methods for the progressive collapse analysis of the hull structure using ANSYS, ALPS/HULL, and IACS CSR methods.  相似文献   

美国“孤立湿地”保护中的“候鸟规则”及对我国湿地保护的启示     

唐双娥  裘丽 《湿地科学与管理》2021,(1):67-72

在美国,孤立湿地与可通航水域没有水文联系,被认为不属于《清洁水法》中的“水域”,联邦无权管辖。为此,陆军工程兵团制定“候鸟规则”,作为对孤立湿地行使管辖权的依据。美国“孤立湿地”保护中的“候鸟规则”对我国的启示在于:(1)应从水文学角度界定孤立湿地,孤立湿地是指与其它水体缺乏联系、相对孤立的湿地,这更符合我国湿地政策的现状;(2)人工“孤立湿地”受保护,除了需满足一定的水文条件,还须是野生动物事实上的栖息地,不应限于建立“栖息地档案”意义下的野生动物栖息地或纳入野生动物重要栖息地名录的栖息地;(3)孤立的人工湿地如果是国家重点保护野生动物栖息地,其管辖权应由中央行使;(4)国家重点保护野生动物栖息地外的其他孤立湿地,面积达到35 hm2以上,也应由中央管辖。  相似文献   

The spatial structure of employment in the metropolitan region of Tokyo: A scale-view     

Yan Li  Tawhid Monzur 《Urban geography》2018,39(2):236-262

Despite Tokyo’s size and position in the global urban system, studies of its employment distribution have been few. This research identified the locations and ranks of the employment centers in the entire metropolitan region and analyzed the characteristics of the economic sectors in those centers by using fine scale economic census data. Minimum sizes for a center were explored at a range from as small as 250 by 250 m to 3,000 by 3,000 m, and the Local Indicators of Spatial Association technique was utilized for detecting centers in different ranks. The results showed that, from a regional view, Tokyo has a typical monocentric or concentric spatial structure. However, from a fine scale view, the distribution was revealed to be expanding along the railroads to the suburbs, and both the main central business district and the suburbs are polycentric. Through this research, the authors argue that rather than using thresholds of total employment and minimum densities as seen in the previous studies, centers can be effectively detected by comparing with the surrounding areas at different scales. This “scale-view” approach of center identification may provide a new perspective to other metropolitan regions of the world as well.  相似文献   

基于数据立方体的多最小支持度关联规则在犯罪分析中的应用     

王海波  张永田  吴升 《测绘科学技术学报》2016,(4):405-409

为了快速获取候选项集的支持度,避免频繁访问数据库而造成效率低下的问题,在MSapriori算法的基础上引入数据立方体,提出DC_MSapriori算法。该算法无需多次扫描事务数据库,减少了I/O操作,降低了搜索开销。实验基于福州市鼓楼区各大医院周边的案事件数据,快速挖掘出犯罪时空模式,验证了算法的有效性。  相似文献   

基于规则的拓扑在地理国情普查空间数据质量检查中的应用     

马建芳 《测绘与空间地理信息》2016,(12):124-126

在研究ArcGIS基于规则的拓扑关系的基础上,探讨了基于规则的拓扑在第一次全国地理国情普查空间数据的质量检查中的应用,并以某县地理国情普查数据为例,进行拓扑关系的创建与验证。  相似文献   

Implications of climate change for the management of North Sea cod (Gadus morhua)   总被引：1，自引：0，他引：1  

Kell  Laurence T.; Pilling  Graham M.; O'Brien  Carl M. 《ICES Journal of Marine Science》2005,62(7):1483-1491

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Another diet of worms: the applicability of polychaete feeding guilds as a useful conceptual framework and biological variable   总被引：1，自引：0，他引：1  

Paulo Roberto Pagliosa 《Marine Ecology》2005,26(3-4):246-254

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