Multidimensional-unified topological relations computation: a hierarchical geometric algebra-based approach     

Linwang Yuan  Zhaoyuan Yu  Wen Luo  Lin Yi  Guonian Lü 《International journal of geographical information science》2014,28(12):2435-2455

This article presents a geometric algebra-based model for topological relation computation. This computational model is composed of three major components: the Grassmann structure preserving hierarchical multivector-tree representation (MVTree), multidimensional unified operators for intersection relation computation, and the judgement rules for assembling the intersections into topological relations. With this model, the intersection relations between the different dimensional objects (nodes at different levels) are computed using the Tree Meet operator. The meet operation between two arbitrary objects is accomplished by transforming the computation into the meet product between each pair of MVTree nodes, which produces a series of intersection relations in the form of MVTree. This intersection tree is then processed through a set of judgement rules to determine the topological relations between two objects in the hierarchy. Case studies of topological relations between two triangles in 3D space are employed to illustrate the model. The results show that with the new model, the topological relations can be computed in a simple way without referring to dimension. This dimensionless way of computing topological relations from geographic data is significant given the increased dimensionality of geographic information in the digital era.  相似文献   

Geospatial spreadsheets with microscale air quality visualization and synchronization for supporting multiple-scenario visual collaboration     

Seung Man An  Ho-Young Lee  Byungsoo Kim  Chae-Yeon Yi  Jeong-Hee Eum 《International journal of geographical information science》2014,28(12):2511-2532

A major obstacle of the interdisciplinary communications for decision-making is that each participant prefers the solution from their own area because current collaboration systems cannot effectively mediate among many alternatives. If a visual collaboration system could display multiple alternatives in a single visual presentation, users would be able to compare alternatives with only a few variables, where all other parameters are fixed, at least from a visual perspective. In this study, we developed a visualization tool to support a microscale air quality (MSAQ) management group, the members of which often need to compare the effects of many alternative control methods. The main achievements of this study are: (1) three-dimensional (3D) visualization of the MSAQ using a 3D city model and (2) development of a geospatial spreadsheet (GS) to facilitate visual comparisons, thereby improving decision-making by making it easy to compare differences based on realistic visual display items. A questionnaire-based survey showed that use of the GS could generate a shared perspective and provide a spatiotemporal context for the participants, thereby making it easy to compare, mediate and reach decisions when confronted with many alternatives.  相似文献   

兰州市地质灾害特征与防治对策研究     

宿星  王得楷  董艳艳  施泽东  张连科 《地质灾害与环境保护》2014,(2):3-6

从地质环境条件、地质灾害特征和城市发展建设方面,分析兰州市地质灾害的成因。从科学技术和社会管理方面,结合国内外的经验和兰州的实际,提出兰州市地质灾害防治的对策和建议。该研究的突破在于把地质灾害防治的科技支撑与社会管理相结合。  相似文献   

科学深钻DPI-1智能化多功能钻参仪的研制与应用研究   总被引：1，自引：0，他引：1  

罗光强 《地质与勘探》2014,50(4):777-782

在科学钻探中,智能化钻参仪被称为“钻井工程的眼睛”。根据深部钻探项目需要,研制了一套DPI-1智能化多功能钻参仪系统,它能检测多路关键钻进参数,自动生成电子班报表,建立数据库管理系统,完成数据近程基地无线传输和远程网络传输。科学钻探现场试验证明,该系统安装简便、测试精度高、稳定性好、实用性强,可广泛适用于配套转盘钻机、立轴钻机、全液压钻机等不同类型钻机。  相似文献   

科学超深井硬岩取心关键技术   总被引：1，自引：0，他引：1       下载免费PDF全文

王稳石  张恒春  闫家 《探矿工程》2014,41(1):9-12

科学超深井是人类观测深部地球的“望远镜”。获取典型区块的原状岩心,建立高分辨率的地层剖面及其物、化性剖面,是科学钻探的最主要的目的之一。在深部钻探中,钻头驱动方式和岩心提取方法,是影响工程能源消耗、施工周期和工程经费的关键因素,从多方面阐述了科学超深井取心钻进多项关键技术和难点,并提出了针对性的解决方案和研究方向。  相似文献   

汶川地震断裂带科学钻探项目WFSD-4孔定向钻进技术应用   总被引：2，自引：0，他引：2       下载免费PDF全文

樊腊生  张伟  吴金生  赵远刚  庄生明 《探矿工程》2014,41(9):101-108,113

介绍了汶川地震断裂带科学钻探项目四号孔定向钻进的施工情况,包括定向钻孔的设计、造斜工具的选择、定向方法、钻孔轨迹控制以及无线随钻定向钻进施工、利用钻具组合进行定向钻进施工、侧钻绕障和定向钻进效果。  相似文献   

汶川地震断裂带科学钻探项目WFSD-4孔钻探施工概况和关键技术   总被引：1，自引：1，他引：0       下载免费PDF全文

吴金生.  张伟  李旭东  段晓青  任福建 《探矿工程》2014,41(9):120-125

介绍了汶川地震断裂带科学钻探项目WFSD-4孔钻探施工概况及采用的关键技术,包括螺杆马达-液动锤-长半合管取心钻进技术、偏心扩孔取心技术、防冲蚀取心钻头技术、大斜度定向钻进技术、活动套管技术、新型钻井液体系和新型深孔取心钻机等。  相似文献   

汶川地震断裂带科学钻探项目WFSD-4孔强缩径地层钻进工艺研究   总被引：1，自引：0，他引：1       下载免费PDF全文

罗光强  张伟  李正前  李旭东 《探矿工程》2014,41(9):130-132，138

介绍了汶川地震断裂带科学钻探项目WFSD-4孔强缩径地层钻进的技术问题。在分析地层缩径机理和影响因素的基础上,提出了强缩径地层的钻进工艺措施。措施在WFSD-4孔中实施取得了显著的效果。  相似文献   

YZX130型液动锤研究及其在WFSD-4孔中的应用          下载免费PDF全文

王跃伟  杨泽英  谢文卫  齐力强  苏长寿  张伟  吴金生 《探矿工程》2014,41(9):143-145

对YZX130型液动锤的结构和工作原理进行了介绍,通过室内调试和测试总结出其主要特点。在WFSD-4孔中的应用证实,YZX130型液动锤可大幅度提高机械效率和回次进尺,尤其在坚硬破碎地层效果更佳,而在塑性较高的软弱松散地层效果则相对较差。  相似文献   

汶川地震断裂带科学钻探项目WFSD-4井钻井液技术          下载免费PDF全文

张林生  陈礼仪  彭刚  张统得 《探矿工程》2014,41(9):146-150

汶川地震断裂带科学钻探项目4号孔（WFSD-4）地层极其复杂,钻探施工难度极大,对钻井液技术要求较高,据此优选钾石灰聚磺钻井液体系为该孔的钻井液主体系。介绍了钻井液技术在各开次的使用维护情况,同时还详细介绍了该孔中的特殊工艺钻井液技术及复杂情况下钻井液应对措施等。  相似文献