检索结果-南通市图书馆

Integral ear elimination and virtual point-based updating algorithms for constrained Delaunay TIN

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2008年第S1期51卷 135-144页

作者： WU LiXin1,2.WANG YanBing2.3 & SHI WenZhong2.4 1 institute for Geo-informatics & Digital Mine research,Northeastern {2.,Shenyang 110004,china 2.institute for gis/rs/gps & subsidence Engineering research,china university of mining & technology,beijing 100085,china 3 Laboratory of 3D Information Acquisition & Application,Capital Normal {2.,beijing 100037,china 4 Center for Advanced gis research,LSGI,Polytechnic {2. Hong Kong,Hong Kong,china Northeastern Univ Inst Geoinformat & Digital Mine Res Shenyang 110004 Peoples R China china Univ mining & Technol Inst GIS RS GPS & Subsidence Engn Res Beijing 100085 Peoples R China Capital Normal Univ Lab Informat Acquisit & Applicat Beijing 100037 Peoples R China Hong Kong Polytech Univ LSGI Ctr Adv GIS Res Hong Kong Hong Kong Peoples R China

Constrained Delaunay Triangular Irregular Networks (CD-TIN),a kind of special data structure,have many practical applications in Geoinformatics,especially in the representation of linear constrained triangulation for DTM and DSM,such as in digital city and digital mine. Past researches on D-TIN mainly focused on point in-sertion and deletion without consideration of constraint,and that on CD-TIN usu-ally paid more attention to the insertion algorithms for points and edges,but little to the deletion algorithms. The presented algorithms are far insufficient for the dy-namic updating of CD-TIN. In this paper,the constraint edge in CD-TIN is consid-ered to be any set of broken lines,i.e.,polygon edges,broken lines and simple segments. The constraint edge may be composed of one or more constraint seg-ments,and it is allowed to be in any form: Open or close,intersection or self-in-tersection. By improving to present insertion and deletion algorithms for D-TIN,two new algorithms for CD-TIN updating are presented. According to the polymorphism of the constraints in CD-TIN,virtual point is adopted to represent the crossing node between constraint edges when a constraint edge is inserted in CD-TIN. Two new algorithms named as Integral Ear Elimination (IEE) and Influence Domain Retrian-gulation for Virtual Point (IDRVP) are presented,the former is for constraint point deletion,while the later is for the insertion and deletion of constraint edge. The principle of IDRVP is that to divide the influence domain of a virtual point into some parts by the constraint-keeping edges,and to retriangulate each part of the influ-ence domain individually referring to the constraint visible property and constraint empty circle (CEC) criterion. Finally,a prototype system is developed with VC++,one case on the integration of 3D terrain and buildings is demonstrated to test the correctness of new algorithms. It shows that the new algorithms are effective for the updating of CD-TIN.

关键词： Delaunay TIN spatial constraint data updating spatial modeling polymorphism digital mine

中国政治经济学年度发展报告（2.2.）（下）

在线全文

学校读者我要写书评

暂无评论

政治经济学评论 2024年第3期 90+207-208页

作者： Center for Studies of Contemporary Political Economy,research institute for 2.st-Century Marxism,Nankai {2.·{2. of Chinese Academy of Social Science Center for Teaching and research on Capital,Renmin {2. of china National institute of Socialist Political Economy with Chinese Characteristics,Renmin {2. of china 南开大学·中国社会科学院大学2.世纪马克思主义研究院当代政治经济学研究中心中国人民大学《资本论》教学与研究中心中国人民大学全国中国特色社会主义政治经济学研究中心

编者按2.2.年，高质量发展扎实推进，新质生产力加快形成，我国经济总体回升向好，圆满实现发展主要预期目标。为针对性地破解经济恢复发展中的难题，聚焦推进中国式现代化进程中的重点、难点问题，中国政治经济学界开展系统深入研究，...

编者按2.2.年，高质量发展扎实推进，新质生产力加快形成，我国经济总体回升向好，圆满实现发展主要预期目标。为针对性地破解经济恢复发展中的难题，聚焦推进中国式现代化进程中的重点、难点问题，中国政治经济学界开展系统深入研究，取得系列代表性成果。为准确刻画学界研究进展和轨迹，推动中国经济学理论体系的构建和完善，本刊精选议题如期奉上《中国政治经济学年度发展报告（2.2.）》。自2.10年起，本刊连续十四年发布《中国政治经济学年度发展报告》，“年度发展报告”专栏已成为本刊标志性特色栏目。2.2.年报告聚焦12.专题，分为（上）（下）两篇，其中专题1—6于报告（上）篇刊登，专题7—12.报告（下）篇刊登。2.2.年报告（下）选题如下：

关键词：

On three-dimensional geological modeling and visualization

同方期刊数据库人大复印报刊资料评论

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2004年第8期47卷 739-748页

作者： WU Qiang1 & XU Hua2.1. Department of Resource Exploitation Engineering, china university of {2. and technology, beijing 100083, china 2. beijing institute of Petrochemical technology, beijing 102.17, china 1. Department of Resource Exploitation Engineering China University of Mining and Technology 100083 Beijing China 2. beijing institute of Petrochemical {2. 102617 Beijing China

The technology of 3D geological modeling will bring about great changes in the methods of geological data acquiring, storing, processing and displaying. However, no perfect or convenient software systems have been developed up to now since the geologic data which re-flect geological entities bear the feature of diversity, uncertainty and complexity. Some supervoxel models, mathematical models of fault and geometrical models of fold have been contrived so as to show the space geometric configuration of the complicated geologic structures. The application-oriented system architecture for 3D geological modeling is established; and a novel design concept based on spatial data processing is also proposed with the technology of solid modeling as its core and the application of models as its objective. Theories and methods for 3D geological modeling will hopefully be enriched and developed. In the light of these theories and methods, a feature-based navigation visualization technique is also put forward in the paper. By integrating geo-database, graphics libraries and KBS with 3D dynamic simulation systems, geologists will be able to capture the partial characteristics and whole structure embodied in the geological data in a direct-viewing, figurative and accurate manner.

关键词： 3D geological modeling,geometrical model,system architecture,visualization

On some tests-based projection pursuit for elliptical symmetry of a high-dimensional distribution

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1998年第6期43卷 450-458页

作者： JING Ping 1 and ZHU Lixing 2.1. Mathematics Lab, china university of mining & technology, beijing 100083, {2. 2. Probability Lab, institute of Applied Mathematics, Chinese Academy of Sciences, beijing 100080, {2. Mathematics Lab China University of Mining & Technology Beijing China Probability Lab Institute of Applied Mathematics Chinese Academy of Sciences Beijing China

Some test statistics of Kolmogorov type and Cramér-von Mises type based on projection pursuit technique are proposed for the testing problem of sphericity of a high-dimensional distribution. The limiting distributions of the test statistics are derived under the null hypothesis and under any fixed alternative. The asymptotic properties of bootstrap approximation are investigated. Furthermore, for computational reasons, an approximation for the statistics, based on the number theoretic method, is suggested.

关键词： bootstrap approximation projection pursuit type statistic elliptical symmetry.

A new method for mining deformation monitoring with gps-RTK

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2011年第S3期21卷 659-664页

作者： GAO Jing-xiang1, 2. LIU Chao2. WANG Jian1, 2. LI Zeng-ke2. MENG Xiang-chao2.1. Key Laboratory for Land Environment and Disaster Monitoring of State Bureau of Surveying and Mapping, china university of {2. and technology, Xuzhou 2.1116, china 2. School of Environment and Spatial Informatics, china university of {2. and technology, Xuzhou 2.1116, china [a] Key Laboratory for Land Environment and Disaster Monitoring of State Bureau of Surveying and Mapping China University of Mining and Technology Xuzhou 221116 China [b] School of Environment and Spatial Informatics China University of Mining and Technology Xuzhou 221116 China

Based on ranging intersection theory, a new method which is simple and easy to operate was proposed for data collection in the mine surface deformation monitoring with gps-RTK centering rod measurements. It can fully eliminate the inevitable shaking error and the vertical deflection, and to some extent weaken the multipath effect on the estimates of coordinates in a relatively short period of time, using high-frequency observations. The results show that three-dimensional coordinates with a height accuracy better than 1 cm, horizontal accuracy better than 2.4 cm can be achieved through only 15-30 s continuous observation by 2. Hz high-frequency and effectively improve the measurement accuracy and efficiency of RTK, fully satisfying the high-speed and high-precision data acquisition in mine surface {2. deformation monitoring.

关键词： gps rover pole multipath delay deformation monitoring

Simulating the impacts of climate variation and land-cover changes on basin hydrology: A case study of the Suomo basin

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2005年第9期48卷 1501-1509页

作者： CHEN Junfeng1,2. LI Xiubin2.& ZHANG Ming2.1. institute of Remote Sensing & gis, Peking {2., beijing 100871, china 2. institute of Geographical Sciences and Natural Resources research, Chinese Academy of Sciences, beijing 100101, china 1. institute of Remote Sensing & gis Peking University 100871 Beijing China 2. institute of Geographical Sciences and Natural Resources research Chinese Academy of Sciences 100101 Beijing Chin

Impacts of land cover changes on watershed hydrology have been a long-term academic concern with acute dispute. But little attention has been paid to such effects on mesoscale river basins, where the society has a closer link to river hydrology. The present study focuses on a mesoscale river basin, the Suomo Basin that is located on the upper reaches of the Yangtze River. Land covers in the basin in the years 1970, 1986 and 1999 were mapped. A lumped hydrologic model, CHARM, and a distributed hydrologic model, SWAT, were used to model the impacts of both land-cover change and climate variation on river runoff during the past four decades. The results show that the contribution of climate variation to the change of runoff regime makes up 60%―80%, while that of land cover changes only 2.%.

关键词： climate variation, land-cover changes, Suomo Basin, CHARM model, SWAT model.

Thermal-mechanical coupled effect on fracture mechanism and plastic characteristics of sandstone

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2007年第6期50卷 833-843页

作者： ZUO JianPing1,2. XIE HePing2.3, ZHOU HongWei1,2.PENG SuPing1 1 State Key Laboratory of Coal Resources and Safe mining, china {2. of mining and technology, beijing 100083, china 2.institute of Rock Mechanics and Fractals, china {2. of mining and technology, beijing 100083, china 3 Sichuan {2., Chengdu 610065, china 1. State Key Laboratory of Coal Resources and Safe mining China University of Mining and Technology Beijing 100083 China 2. institute of Rock Mechanics and Fractals China University of Mining and Technology Beijing 100083 China 3. Sichuan university Chengdu 610065 China

Scanning electronic microscopy (SEM) was employed to investigate fractographs of sandstone in mine roof strata under thermal-mechanical coupled effect. Based on the evolution of sandstone surface morphology in the failure process and frac- tography, the fracture mechanism was studied and classified under meso and mi- cro scales, respectively. The differences between fractographs under different tem- peratures were examined in detail. Under high temperature, fatigue fracture and plastic deformation occurred in the fracture surface. Therefore, the temperature was manifested by these phenomena to influence strongly on micro failure mechanism of sandstone. In addition, the failure mechanism would transit from brittle failure mechanism at low temperature to coupled brittle-ductile failure mechanism at high temperature. The variation of sandstone strength under differ- ent temperature can be attributed to the occurrence of plastic deformation, fatigue fracture, and microcracking. The fatigue striations in the fracture surfaces under high temperature may be interpreted as micro fold. And the coupled effect of tem- perature and tensile stress may be another formation mechanism of micro fold in geology.

关键词： sandstone, thermal-mechanical coupled effects, fractograph, plastic deformation, SEM, micro fold

Dynamic mechanisms of the post-seismic deformation following large events:Case study of the 1999 Chi-Chi earthquake in Taiwan of china

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2009年第11期52卷 1813-1824页

作者： ZHU ShouBiao1,2.& CAI YongEn2.1 institute of Crustal Dynamics, china Earthquake Administration, {2., china 2.Department of Geophysics, Peking university, beijing 100871, china 1. institute of Crustal Dynamics China Earthquake Administration Beijing 100085 China 2. Department of Geophysics Peking University Beijing 100871 China

The mechanism of postseismic deformation related to strong earthquakes is important in geodynamics, and presumably afterslip or viscoelastic relaxation is responsible for the postsesimic deformation. The 1999 Chi-Chi, Taiwan of china, earthquake occurred in the region where {2. observation station is most densely deployed in the world. The unprecedented {2. data provides a unique opportunity to study the physical processes of postseismic deformation. Here we assume that the interactions of viscoelastic relaxation, afterslip, fault zone collapse, poroelastic rebound, flow of underground fluids, and all these combined contribute to the surface displacements following the main shock. In order to know the essence of the postseismic deformation after the strong event, fault zone collapse, poroelastic rebound, flow of underground fluids, and so on, are represented equivalently by the variations of the focal medium properties. Therefore, the viscoelastic relaxation, afterslip, and the variations of the equivalent focal medium properties are inverted by applying the {2. temporal series measurement data with viscoelastic finite element method. Both the afterslip rate distribution along the fault and the afterslip evolution with time are obtained by means of inversion. Also, the preliminary result suggests that viscosities of the lower crust and the upper mantle in Taiwan region is 2.7×1018 and 4.2.102. Pa·s, respectively. Moreover, the inversion results indicate that the afterslip contributing to postseismic deformation of 44.6% in 450 days after the Chi-Chi earthquake, with 34.7% caused by the viscous relaxation and 2..7% by other factors such as fault zone collapse, poroelastic rebound, and the flow of liquids.

关键词： mechanism of postseismic deformation viscoelastic finite element method gps temporal series data Chi-Chi earthquake

林克明旧居修缮与活化利用,广州,广东,中国

在线全文

学校读者我要写书评

暂无评论

世界建筑 2024年第8期 64-69页

作者： Guangdong Architectural Design and research institute Group Co.,Ltd. Architectural Design and research institute of South china university of technology 广东省建筑设计研究院集团股份有限公司华南理工大学建筑设计研究院有限公司

街区断点更新林克明旧居(简称旧居)1935年由中国第一代著名建筑师林克明设计建造。旧居所在的越秀北路原为民国初年广州城墙拆除后的城基路,城外即东濠涌,前后高差达8m。林克明巧妙地利用地形组织功能与空间,并采用摩登建筑理念,使建筑... 详细信息

街区断点更新林克明旧居(简称旧居)1935年由中国第一代著名建筑师林克明设计建造。旧居所在的越秀北路原为民国初年广州城墙拆除后的城基路,城外即东濠涌,前后高差达8m。林克明巧妙地利用地形组织功能与空间,并采用摩登建筑理念,使建筑形体呈现出迷人的风采。

关键词：建筑形体建筑理念活化利用功能与空间著名建筑师林克明修缮城墙