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21.
已有的线群目标几何相似性度量方法主要基于数理统计的思想,通过统计整体变化信息计算几何相似性,缺少对局域特征的表达,并不适用于具有高度分形特征的河系。为此,本文将河系几何特征划分为3层次的信息特征:单条河流的形状特征、局部区域的结构特征、全局范围的分布特征。首先,结合角链码法与Hausdorff距离计算单条河流的形状相似度;然后,根据 “二八定律”确定局部特征区域,通过坐标系转换计算M: N的河系局域结构相似度;最后综合整体描述子得到全局分布相似度,并在该基础上,构建差异指标进行河系多尺度相似性计算与综合质量评价。实验表明,该方法的计算结果优于均值指标法,能有效应用于制图综合的质量评价。 相似文献
22.
MORPHOLOGIC EQUATIONS BASED ON THE PRINCIPLE OF MAXIMUM ENTROPY 总被引:1,自引:0,他引:1
MORPHOLOGICEQUATIONSBASEDONTHEPRINCIPLEOFMAXIMUMENTROPYDENGZhiqiang;ZHANGKaiquanAbstract:Theprincipleofmaximumentropyisusedto... 相似文献
23.
Jón EIR 《Frontiers of Earth Science》2008,2(4):449-457
A high-resolution diatom record from core MD99-2275 shows a general paleoceanographic change in the northern North Atlantic
since 5000 cal. a B.P. by Principle Component Analysis. Sea surface temperature (SST) increased gradually during 5000 and
3000 cal. a B.P. on the North Icelandic shelf as a result of increasing influence of warm Atlantic water mass from the Irminger
Current. It apparently started to decrease since 3000 cal. a B.P. due to the weakening influence of warm water and enhanced
influence of the Polar and Arctic water masses from the East Greenland Current and the East Icelandic Current. Abrupt decreases
in SST and intrusions of Polar and Arctic water superimposed on the late Holocene cooling trend during 3000-2600, 1300-1000
and 600-200 cal. a B.P.. The paleoceanographic record revealed from core MD99-2275 corresponds well with δ18O record from the GISP2 and is generally consistent with other SST records based on diatom on the North Icelandic shelf.
__________
Translated from Marine Science Bulletin, 2008, 27(5) [译自:海洋通报] 相似文献
24.
Asian monsoon have multiple forms of variations such as seasonal variation, intra-seasonal variation, interannual variation,
etc. The interannual variations have not only yearly variations but also variations among several years. In general, the yearly
variations are described with winter temperature and summer precipitation, and the variations among several years are reflected
by circulation of ENSO events. In this study, at first, we analyze the relationship between land cover and interannual monsoon
variations represented by precipitation changes using Singular Value Decomposition method based on the time series precipitation
data and 8km NOAA AVHRR NDVI data covering 1982 to 1993 in east Asia. Furthermore, after confirmation and reclassification
of ENSO events which are recognized as the strong signal of several year monsoon variation, using the same time series NDVI
data during 1982 to 1993 in east Asia, we make a Principle Component Analysis and analyzed the correlation of the 7th component
eigenvectors and Southern Oscillation Index (SOI) that indicates the characteristic of ENSO events, and summed up the temporal-spatial
distribution features of east Asian land cover’s inter-annual variations that are being driven by changes of ENSO events. 相似文献
25.
试用主分量分析方法提取澜沧江兰坪地区铜矿化蚀变遥感信息 总被引:7,自引:3,他引:7
通过图像影像特征分析,并经地面调查证实,澜沧江兰坪地区铜矿化蚀变与围岩存在反射波谱特性差异,即在TM5(近红外)波段(1.55μm-1.75μm)蚀变岩呈高反射率。以此为依据,进行了提取与铜矿化蚀变相关的TM遥感信息的计算机图像处理技术方法研究。实践证明,该区主分量分析处理图像效果最佳。图像上显示的色调异常,通过与红土涧矿区地质勘查资料对比和根据兰坪地区图像上典型地物样区色调理论分析,评价了遥感异常的地质意义。由于图像预处理(几何校正、亮度拉伸、多元统计,最佳波段组合选择等)是针对澜沧江兰坪全区的特征进行的,故处理方法在全区内均有一定适用性。本文结合公式2、图4、表4、封二彩片5等实际材料较详细地介绍了有关提取铜矿化蚀变遥感色调异常信息的方法技术。 相似文献
26.
集群技术越来越多地应用在提高系统的稳定性和对数据中心的保护等关键应用领域。本文简述了高可用集群技术的有关概念、Veritas Cluster Server工作原理以及湖北省国土资源电子政务系统如何利用高可用性集群搭建数据库和GIS应用服务的相关案例。 相似文献
27.
Slope failure is very common phenomenon in hilly regions, especially in young techno active mountainous like Himalayas. It
is hazardous because of the accompanying progressive movement of the slope-forming material. In order to minimize the landslide
effects, slope failure analysis and stabilization requires in depth understanding of the process that governs the behavior
of the slope. The present article mainly deals with the analysis of the stability of road cut slopes of Rudraprayag Area,
Uttarakhand, India. The area experiences local as well as regional slides every year. Extensive field study was carried out
along the road cut slopes. Laboratory experiments were conducted to determine the various Physio-mechanical properties of
rock mass. These properties have been used as input parameters for the numerical simulation of slope using FLAC3D (Fast Lagrangian
Analysis of Continua) including geological discontinuities. The computed deformations and the stress distribution along the
failure surface are compared with the field observations. The study indicates that the overall slope is unstable except at
the location E where slope is critically stable. The effects of instability have been thoroughly considered and remedial measures
have been recommended. 相似文献
28.
本文回顾了中国东南沿海滨海地带几例历史大地震造成的巨大灾害;讨论了由定数法所确定的地震烈度折算成抗震设计参数的关系,以及由概率法取得的地震动参数直接作为抗震设防依据的重要性;简述了地震小区划方法;指出开展滨岸地带港口城市,开发区和重大工程场地的地震小区划工作对减轻地震灾害的深远意义。 相似文献
29.
黎政 《广东海洋大学学报》2006,26(2):103-107
《邓小平文选》是领导者语言的范例,存在大量的礼貌现象.体现着礼貌的思想。它们的运用可以给交际对方留面子,从而使交际活动更好地进行下去。以Brown和Levinson的面子保全论为理论基础,运用Leeoh的礼貌原则及六个次准则分析了《邓小平文选》领导语言中的各种礼貌的语言现象,其实现途径以及它的内在语用机制。这说明礼貌理论对文本交际活动也具有很强的阐释力。 相似文献
30.