基于图像退化模型的天气现象识别     

宋晓建  杨玲 《成都信息工程学院学报》2011,(4):132-136

在不同的天气条件下,由于气溶胶对光波的散射作用,通过成像系统获得的图像都会有一定程度的退化。利用图像的退化模型可以获取与天气现象相关的参量,从而达到识别天气的目的。对不同天气条件下得到的同一场景图进行研究,运用多垂线检测法,检测出不同天气条件下直线模糊边缘上的灰度值,采用signloid函数拟合出刃边函数,进而求出线扩散函数。通过分析线扩散函数的变化规律,总结出其与天气现象之间的紧密联系。测试结果表明,应用该方法对于晴天、薄雾、雨、霾、沙尘暴等天气现象具有一定的判别效果。  相似文献   

用于可重构机床控制系统的电力线通信技术     

杨东升  郇极  Stefan Schmitz 《地理研究》2011,37(9)

介绍了可重构机床对通信系统的要求,提出了一种基于宽带电力线通信（PLC,PowerLine Communication）技术的新型通信系统．通过对机床电力线的信道特性和噪声频谱的分析与测量,选定了通信系统的载波频率和带宽等参数．为了对抗电力线信道的多径效应,提高频谱利用率,实现可靠高效的数据传输,采用正交频分复用技术（OFDM,Orthogonal Frequency Division Multiplex）作为调制解调方式．开发了PLC调制解调器,定义了物理层帧结构．最后以机床主轴伺服系统为例对该通信系统进行了实验验证．实验结果表明,该系统实现了有效数据传输率10Mbit／s,误比特率（BER,Bit Error Rate）小于10^-8的高效数据传输．  相似文献   

Variability of atmospheric freezing level height derived from radiosonde data in China during 1958–2005 and its impact to cryosphere changes     

YanJun Guo  YinSheng Zhang 《寒旱区科学》2011,3(6):0485-0490

Atmospheric air temperature data from 92 stations in China’s radiosonde network were used to analyze changes in the freezing level height (FLH), glacier snow line, and ice edge from 1958–2005 (48 years) and to examine the impact of these changes on the cryosphere. In general, the FLH, glacier snow line, and ice edge exhibited latitudinal zonation, declining from south to north. Trends in the FLH, glacier snow line, and ice edge showed spatial heterogeneity during the study period, with prevailing upward trends. Temporally, the FLH, glacier snow line, and ice edge trends differed on various time scales.  相似文献   

基于形态分割的高分辨率遥感影像道路提取   总被引：27，自引：1，他引：26  

朱长青  王耀革  马秋禾  史文中 《测绘学报》2004,33(4):347-351

基于灰度形态学,提出一种从高分辨率遥感图像提取道路网络的方法.首先利用灰度形态特征对遥感影像进行分割,进而得到基本的道路网络轮廓.然后在此基础上,利用线段特征匹配方法提取道路网络.提出的方法能适应于从道路和背景区别不很清楚的遥感图像中提取道路.实验结果也表明,本文方法能有效地从遥感影像中提取道路网络.  相似文献   

RTK技术在送变电线路测量中的应用   总被引：3，自引：1，他引：2  

吕忠刚 《测绘与空间地理信息》2004,27(5):69-71

在简介RTK技术的基础上,分析和研究了RTK技术在送变电工程测量中各阶段的主要应用,提出了具体的应用方法,指出了应用中应注意的主要问题与解决的技术措施,对工程应用具有一定的指导意义。  相似文献   

GIS‐evaluation of two slope‐calculation methods regarding their suitability in slope analysis using high‐precision LiDAR digital elevation models     

M. Irfan Ashraf  Zhengyong Zhao  Charles P.‐A. Bourque  Fan‐Rui Meng 《水文研究》2012,26(8):1119-1133

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Stratigraphic architecture and sedimentology of a Late Pleistocene subaqueous moraine complex,southwest Ireland     

David J. A. Evans  John F. Hiemstra  Colm Ó Cofaigh 《第四纪科学杂志》2012,27(1):51-63

Glacigenic sediments exposed in coastal cliffs cut through undulatory terrain fronting the Last Glacial Maximum laterofrontal moraine at Waterville on the Iveragh Peninsula, southwest Ireland, comprise three lithofacies. Lithofacies 1 and 2 consist of interdigitated, offlapping and superimposed ice‐proximal subaqueous outwash and stacked sequences of cohesionless and cohesive subaqueous debris flows, winnowed lag gravels and coarse‐grained suspension deposits. These are indicative of sedimentation in and around small grounding line fans that prograded from an oscillating glacier margin into a proglacial, interlobate lake. Lithofacies 3 comprises braided river deposits that have undergone significant syn‐sedimentary soft‐sediment deformation. Deposition was likely related to proglacial outwash activity and records the reduction of accommodation space for subaqueous sedimentation, either through the lowering of proglacial water levels or due to basin infilling. The stratigraphic architecture and sedimentology of the moraine at Waterville highlight the role of ice‐marginal depositional processes in the construction of morphostratigraphically significant ‘end moraine’ complexes in Great Britain and Ireland. Traditional ‘tills’ in these moraines are often crudely stratified diamictons and gravelly clinoforms deposited in ice‐proximal subaqueous and subaerial fans. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

基于卡西欧fx-4800P计算器的附合导线近似平差程序     

王景海  刘春彦 《北京测绘》2010,(1):73-75

卡西欧fx-4800P计算器近年来普遍应用于工程测量工作中。针对卡西欧fx-4800P计算器具体特点,编制附合导线近似平差计算程序,并演示算例,可以提高计算准确率与工作效率。  相似文献   

利用全站仪直线放样功能测量定线的精度分析   总被引：2，自引：0，他引：2  

何英伟  刘飞  曹军奇  徐思睿 《北京测绘》2010,(4):35-38

针对测量定线过程中出现的问题,介绍了全站仪直线放样功能用于测量定线的基本原理,并对测线上的转点和整条测线进行了精度分析。为了提高测线精度,提出了依据实地观测条件,分别在各测线段引入转点分段测量的方法。  相似文献   

An interconnect width and spacing optimization model considering scattering effect     

朱樟明  万达经  杨银堂 《海洋学报(英文版)》2010,29(9)

As the feature size of the CMOS integrated circuit continues to shrink, the more and more serious scattering effect has a serious impact on interconnection performance, such as delay and bandwidth. Based on the impact of the scattering effect on latency and bandwidth, this paper first presents the quality-factor model which optimises latency and bandwidth effectively with the consideration of the scattering effect. Then we obtain the analytical model of line width and spacing with application of curve-fitting method. The proposed model has been verified and compared based on the nano-scale CMOS technology. This optimisation model algorithm is simple and can be applied to the interconnection system optimal design of nano-scale integrated circuits.  相似文献