General Entropy Model of Line Segments Uncertainty in GIS     

SHI Yufeng SHI Wenzhong School of Architecture Engineering  Shandong University of Technology  Zhangzhou Road  Zibo  China  Key Laboratoryof Geospace Environment  Geodesy  Ministry of Education  Wuhan University  Luoyu Road  Wuhan  China. 《地球空间信息科学学报》2007,10(1):61-66

Spatial data uncertainty can directly affect the quality of digital products and GIS-based decision making. On the basis of the characteristics of randomicity of positional data and fuzziness of attribute data, taking entropy as a measure, the stochastic entropy model of positional data uncertainty and fuzzy entropy model of attribute data uncertainty are proposed. As both randomic-ity and fuzziness usually simultaneously exist in linear segments, their omnibus effects are also investigated and quantified. A novel uncertainty measure, general entropy, is presented. The general entropy can be used as a uniform measure to quantify the total un-certainty caused by stochastic uncertainty and fuzzy uncertainty in GIS.  相似文献   

Climatic significance of δ~(18)O records from an 80.36 m ice core in the East Rongbuk Glacier, Mount Qomolangma (Everest)     

Paul A. Mayewski 《中国科学D辑(英文版)》2005,(2)

The δ18O variations in an 80.36 m ice core retrieved in the accumulation zone of the East Rongbuk Glacier, Mount Qomolangma (Everest), is not consistent with changes of air temperature from both southern and northern slopes of Himalayas, as well as these of the temperature anomalies over the Northern Hemisphere. The negative relationship between the δ18O and the net accumulation records of the ice core suggests the "amount effect" of summer precipitation on the δ18O values in the region. Therefore, the δ18O records of the East Rongbuk ice core should be a proxy of Indian Summer Monsoon intensity, which shows lower δ18O values during strong monsoon phases and higher values during weak phases.  相似文献   

抗滑桩内力计算“K”法的改进与应用   总被引：4，自引：0，他引：4  

戴自航  彭振斌 《地质与勘探》2002,38(3):79-83

对传统的抗滑桩内力计算“K”法作了一些改进,如建立了滑动面上下统一的坐标系,将桩视为一个整体进行考虑,通过合理的假定,保证了桩身在滑动面处内力和位移的连续性,同时,采用名的MATLAB数学软件设计了“K”法的计算程序,适用于滑坡推力和桩前滑体抗力分布的各种形式以及抗滑桩为刚性桩和弹性桩的情况,实例计算结果表明,较之传统的查表法,该方法有效地提高了抗滑桩内力和位移计算速度和精度,同时可得到理想的可视化计算结果,有助于抗滑桩结构的优化设计。  相似文献   

IAP AGCM中短波辐射方案的改进研究I·引入Fu-Liou短波辐射方案     

张凤 《气候与环境研究》2005,(3)

冰云和水云对短波辐射性质(消光系数、单次散射反照率及不对称因子)的影响很不相同,应分别计算。Fu-Liou短波辐射方案(以下称Fu-Liou code)就是对冰云和水云分别采用了不同的参数化方案,云的短波辐射性质直接由云的物理性质来确定。因此,Fu-Liou code在云的处理方面物理意义更清晰且很合理。作者将Fu-Liou code引入IAP AGCM-II中,称为Version 2。对当代气候场的模拟结果表明,Version 2的各个物理过程是协调匹配的,且其对气候场的模拟性能是好的,从而为进一步改进IAP AGCM的短波辐射方案提供了很好的模式基础。  相似文献   

CLIMATE ANOMALY RECORDED IN GULIYA ICE CORE AND ENSO EVENTS          下载免费PDF全文

杨梅学  姚檀栋 《Acta Meteorologica Sinica》2000,(2)

Examination of ENSO events and the accumulated precipitation and δ~(18)O values recorded in theGuliya ice core,China,shows that the relationship between the occurrence of ENSO events and theprecipitation anomaly in Guliya is significant.In the years of El Nino events,the anomalies ofprecipitation and δ~(18)O values in the Guliya ice core were negative anomalies,that is,the ENSO eventsare related to the deficit of precipitation as well as low temperature in the western China.  相似文献   

Autumn intensification of the Ryukyu Current during 2003-2007   总被引：2，自引：0，他引：2  

ZHU Xiao-Hua  HUANG DaJi & GUO XinYu State Key Laboratory of Satellite Ocean Environment Dynamics  Second Institute of Oceanography  State Oceanic Administration  Hangzhou  China  Center for Marine Environmental Study  Ehime University  - Bunkyo-cho  Matsuyama -  Japan 《中国科学:地球科学(英文版)》2010,(4)

Inverse calculations using data from 16 repeat hydrographic transects collected from April 2003 to June 2007 have yielded velocity structures and volume transports(VTs) of the Ryukyu Current in the region east of the northern Ryukyu Islands.The inverse calculation results show that the Ryukyu Current is dominated by a subsurface velocity core with maximum velocities from 15.1 to 80.0 cm/s,whose positions vary between 110 and 600 dbar and 27.2°-28.2°N along the transect.The mean velocity exhibits a subsurface velocity core with a maximum value of 24.6 cm/s at 326 dbar depth,a VT of 14.0 Sv(1 Sv≡106 m3/s),a vertical dimension of 800 m,and a horizontal dimension of 60 km.The seasonal mean velocities show that the Ryukyu Current is stronger in autumn than in other seasons.It is suggested that this seasonal variation is coincident with the intensification of the anticyclonic eddy south of Shikoku,Japan.  相似文献   

基于GOCE卫星重力测量技术确定地球重力场的研究     

钟波 《测绘学报》2011,40(4):535

随着GOCE卫星的成功发射,围绕GOCE数据处理和应用研究已成为目前地学研究的热点问题之一。本文研究基于GOCE卫星重力测量技术确定地球重力场的理论和方法,研制相应的数据处理软件包与仿真模拟平台。论文的主要工作如下：  相似文献   

江西南部武夷群及其地质时代   总被引：3，自引：0，他引：3  

巫建华  项媛馨  刘帅 《地层学杂志》2011,(2):200-208

江西南部三百山、蔡坊、版石、岩背等火山盆地由长英质火山岩组成,岩石组合与北武夷地区的武夷群一致,可归人武夷群,并可进一步划分出双峰岭和鹅湖岭两个组.错石SHRIMP U-Pb测年结果表明,三百山盆地粗面岩的年龄为142.0±1.0Ma,蔡坊盆地流纹岩的年龄为131.4±1.3Ma,版石盆地围东一带流纹质凝灰岩的年龄为1...  相似文献   

Selected Trace Elements in Snowpack on Urumqi Glacier No. 1, Eastern Tianshan, China: As Yielded by Leaching Treatment Representative of Real-World Environmental Conditions     

张明军  王圣杰  王飞腾  李月芳 《中国地质大学学报(英文版)》2011,(4)

To investigate the seasonal variability and potential environmental significance of trace elements in mountain glaciers, the surface snow and snow pit samples were collected at Urumqi Glacier No. 1 (43o06'N, 86o49'E, 4 130 m a.s.l.), eastern Tianshan (天山), from September 2002 to September 2003, and analyzed for Li, V, Cr, Mn, Co, Cu, and Ba. The samples were acidified (leached) in a manner intended to reasonably approximate the extent to which the natural hydrologic and weathering cycles would liberate elem...  相似文献   

Rapid Shrinking of Glaciers in the Middle Qilian Mountain Region of Northwest China during the Last ～50 Years     

王璞玉  李忠勤  高闻宇 《中国地质大学学报(英文版)》2011,(4)

During the past five decades, fluctuations of glaciers were reconstructed from historical documents, aerial photographs, and remote sensing data. From 1956 to 2003, 910 glaciers investigated had reduced in area by 21.7% of the 1956 value, with a mean reduction for the individual glacier of 0.10 km2. The relative area reductions of small glaciers were usually higher than those of large ones, which exhibited larger absolute loss, indicating that the small glaciers were more sensitive to climate change than la...  相似文献