网络分层用于最短路问题的算法研究     

付江缺  高井祥  段春燕  孙正明 《测绘科学》2009,34(3)

提出了一种基于Dijkstra方法的网络分层算法,实现了两点间节点数最少条件下最短通路的求取,并与传统Dijkstra算法进行了比较,得到了一些有益的结论。  相似文献   

Global sea level change and thermal contribution   总被引：4，自引：0，他引：4  

Juncheng Zuo  Jianli Zhang  Ling Du  Peiliang Li  Lei Li 《中国海洋大学学报(英文版)》2009,8(1):1-8

The global long-term sea level trend is obtained from the analysis of tide gauge data and TOPEX/Poseidon data. The linear trend of global mean sea level is highly non-umiform spatially, with an average rate of 2.2 mm year-1 in T/P sea-level rise from October 1992 to September 2002. Sea level change duc to temperature vanation (the thermosteric sea level) is discussed. The results are compared with TOPEX/Poseidon altimeter data in the same temporal span at different spatial scales. It is indicated that the ther-mal effect accounts for 86% and 73% of the observed seasonal variability in the northern and southern hemispheres, respectively. The TOPEX/Poseidon observed sea level lags behind the TSI, by 2 months in the zonal band of 40°-60° in both the northern and southern hemispheres. Systematic differences of about 1-2cm between TOPEX/Poseidon observations and thermosteric sea level data are obtained. The potential causes for these differences include water exchange among the atmosphere, land, and oceans, and some pos-sible deviations in thermosteric contribution estimates and geophysical corrections to the TOPEX/Poseidon data.  相似文献   

鄂霍次克海南部晚第四纪的古海洋学记录   总被引：1，自引：0，他引：1  

孙烨忱  王汝建  陈建芳  高爱国  李秀珠  韩贻兵 《海洋地质与第四纪地质》2009,(2)

鄂霍次克海是太平洋第二大边缘海,在西北太平洋水文环境中扮演重要角色。综合分析了鄂霍次克海南部T00孔沉积物的多种替代性指标,揭示了鄂霍次克海晚第四纪以来的环境变化受季节性海冰变化、大气循环模式、陆源物质通量和表层生产力的共同影响。对比放射虫Cycladophora davisiana的含量曲线与LR04氧同位素记录,该孔沉积物可划分为氧同位素1-7期,底部年龄约为250ka。C.davisiana在间冰期的高含量表明鄂霍次克海中层水是北太平洋中层水的主要源区。蛋白石和有机碳的分析显示鄂霍次克海表层生产力在冰消期突然增大,随后在间冰期逐渐下降,冰期普遍较低。C/N比值曲线的分析说明鄂霍次克海的有机质沉积物主要来源于海洋。沉积物粒度的分析揭示鄂霍次克海冰期时陆源粗颗粒含量较低,至冰消期粗颗粒含量突然增加,而在间冰期陆源粗颗粒含量较高。  相似文献   

ERDAS IMAGINE在1∶50000土壤底图纠正中的应用     

高晖  范兰  韩东明 《测绘标准化》2009,(4):36-38

目前利用ERDAS IMAGINE软件进行影像纠正的技术和工艺已日益成熟和完美。通过ERDAS IMAGINE在1∶50000土壤底图纠正中的应用,从生产的角度叙述了ERDAS IMAGINE软件在影像纠正中的关键技术问题,主要包括基础地理信息数据的处理、地面控制点的选取和控制点的判读。  相似文献   

GIS数据质量控制技术在地籍数据库建设中的应用   总被引：2，自引：1，他引：1  

陈春华  余红举  高淑芬  龚卉 《地理空间信息》2009,7(1):31-33

对GIS数据质量控制技术在地籍数据建库中的应用进行了研究，在地籍数据库建设质量控制实践中综合运用了过程控制法和软件检查法，有效地控制地籍建库各个阶段的精度，保证最终成果满足设计要求。  相似文献   

GPS/VRS虚拟观测值生成与发布研究     

袁本银  高成发  柯福阳  潘树国 《测绘工程》2009,18(5):27-30

虚拟参考站（VRS）技术是目前GPS网络RTK系统研究领域的热点之一。介绍VRS系统的组成及原理;论述VRS虚拟观测值的生成算法及发送给用户后随机商业软件的解算模型;最后介绍算法的软件系统实现,通过与真实观测值比较的方法验证虚拟观测值的可行性和稳定性。  相似文献   

Sediment texture and grain-size implications: the Changjiang subaqueous delta   总被引：3，自引：1，他引：2  

ZHANG Rui  WANG Yaping  GAO Jianhu  PAN Shaoming 《海洋学报(英文版)》2009,28(4):38-49

Sediment cores were collected from the subaqueous delta of the Changjiang Estuary. Sediment grain-size profiles and their fractal dimensions were analyzed, to elucidate responses to long-term sedimentary processes. In addition, the environmental sensitive populations of grain size have been extracted. The sediment cores can be divided into two parts, according to the sedimentary structures present. The upper part (0-12 cm) is interpreted as being the active layer, which is influenced frequently by changes i...  相似文献   

On tectonic movement in the South China Sea during the Cenozoic   总被引：1，自引：1，他引：0  

LIN Changsong  CHU Fengyou  GAO Jinyao  TAN Yonghua 《海洋学报(英文版)》2009,28(1):25-36

The tectonic movement taking place at the end of Cretaceous and the beginning of Cenozoic had opened the Cenozoic phase of polycyclic tectonic movements, then the whole crust of the South China Sea had been mainly subjected to the regional stress field of tectonic tension, which was characterized by rifting depression. Seven times of regional tectonic movement and sedimentation had been assembled into a geological development history of polycyclic oscillation. Especially, the tectonic movements were strongly intensified at the end of Cretacious and the beginning of Paleagene, between Late Eocene and MidOligocene, during Mid and Late Miocene. These three times of tectonic movement had built the most important regional tectonic interfaces in the South China Sea. Crust movements of the South China Sea were the result and epitome of interaction of the Eurasia, Pacific and IndoAustralia plates, that is, they were introduced by polycyclic changes of directions, rates and strengths of lithospheric movements and asthenospheric flows across the Pacific and IndoAustralia plates.  相似文献   

Characterization of marine microplankton communities of Qingdao coastal areas using randomly amplified polymorphic DNA（RAPD）   总被引：1，自引：1，他引：0  

GAO Shan  HU Xiaozhong  CHEN Zigui  XU Henglong  YI Zhenzhen  LIN Xiaofeng  LIJiqiu 《海洋学报(英文版)》2009,28(1)

Microplankton communities of three coastal sites of Qingdao, Shandong Province, China were investigated using RAPD (random amplified polymorphic DNA) molecular markers and morphological observations. Eight RAPD-primers were selected to amplify the DNA polymorphy. The genetic distances inferred from the pairwise similari-ties were calculated for the phylogenetic tree construction. Meantime, the traditional microscopic determination, a way of visualizing the species composition, was performed to detect the major taxa of microplanktons from all samples. Results showed that: (1) the band sharing index values were in the range of 0. 504 2-0. 763 2 among samples from the same sampling site at different time scales, while 0.406 5-0.685 7 among the samples from different stations at the same time scales, indicating that spatial variations of microplankton communities were more pronounced than temporal ones; (2) samples from the same station basically clustered together, cor-responding to the geographic distribution of the sampling sites; (3) diversity derived from genetic and morpho-logical data did not correspond with each other well.  相似文献   

基于FME的土地管理数据共享途径的探讨     

陈春平  高飞  胡小华 《四川测绘》2009,32(6):254-256

对空间数据共享的实现方法及土地管理数据进行了简单介绍，在分析FME体系结构的基础上给出了在土地管理中利用FME解决问题的实例，同时探讨了利用FME Objects及FME Server实现土地管理数据共享的具体开发方案。  相似文献