Web2.O环境下基于布鲁克斯方程的地图信息传输模型     

赵晶辉  尹章才  张世伟  李彦鹤  周沂  吴迎霞 《测绘科学》2011,36(6):164-166

各向地图信息传输模型是传统地图信息传输理论在Web2.0时代的延伸与发展,对提升现代地图学的价值具有重要意义.本文通过分析Web2.0地图的特点和相关工作,研究地图制图模式及其相应的地图信息传输模型,引入信息生态学和布鲁克斯方程,重点探索了基于Web2.0地图的各向地图信息传输模型,利用信息学的布鲁克斯方程对Web2....  相似文献   

基于三维激光扫描技术的超高压输电线路巡线技术研究     

王永波  盛业华 《测绘科学》2011,36(5):60-61,59

本文将三维激光扫描技术应用于超高压输电线路的检测与维护中。与传统的线路检测与维护方法相比较,三维激光扫描技术提供了一种方便、快捷、高效的三维数据获取手段,在此基础上,方便地计算超高压输电线路维护过程中所需的各项参数,如档距、高差、弧垂、导线的相间距离等。一方面,可以有效地论证输电线路的设计方案是否合理;另一方面,也可以合理确定故障频发地段,为电网的安全稳定运行提供了可靠的技术保障。  相似文献   

Transmission and visualization of large geographical maps   总被引：1，自引：0，他引：1  

Liqiang Zhang  Liang ZhangYingchao Ren  Zhifeng Guo 《ISPRS Journal of Photogrammetry and Remote Sensing》2011,66(1):73-80

Transmission and visualization of large geographical maps have become a challenging research issue in GIS applications. This paper presents an efficient and robust way to simplify large geographical maps using frame buffers and Voronoi diagrams. The topological relationships are kept during the simplification by removing the Voronoi diagram’s self-overlapped regions. With the simplified vector maps, we establish different levels of detail (LOD) models of these maps. Then we introduce a client/server architecture which integrates our out-of-core algorithm, progressive transmission and rendering scheme based on computer graphics hardware. The architecture allows the viewers to view different regions interactively at different LODs on the network. Experimental results show that our proposed scheme provides an effective way for powerful transmission and manipulation of large maps.  相似文献   

雷达资料传输质量的影响因素及应对措施     

赵瑞金  杨海龙 《气象科技》2011,39(1):76-82

介绍了河北省目前新一代天气雷达传输与共享资料的种类及实现方法,并结合近年来河北省雷达资料传输的实际情况对影响雷达数据传输的主要因素进行了分析。指出影响新一代天气雷达资料传输质量的因素来自网络和通信线路、传输软件、雷达设备和人为因素等多个环节,并给出了各种影响因素相应的处理措施,为新一代天气雷达的资料共享、监控和提高雷达资料业务传输质量提供参考。  相似文献   

田东35KV输电线路防雷设计分析     

黄伟圣  陈瑜琨 《气象研究与应用》2011,32(1):90-93,105

对广西田东县35KV输电线路进行防雷措施进行设计时,综合考虑当地气候、地形、环境等多种因素,并进行雷击风险评估工作,给出了最佳的防雷保护方案,从而有效地降低输电线路雷击跳闸率,减少雷电对电网安全运行的影响.  相似文献   

多重散射问题的改进算法以及双排非连续弹性屏障对水平向剪切波的隔离研究     

夏唐代  孙苗苗  陈晨 《岩土力学》2011,32(8):2402-2408

与Aviles等学者的多重散射隔振理论相比较,采用更为完整的Fourier-Bessel函数系的级数展开表达式来研究弹性波入射下的多重散射问题。引入Graf加法定理,并结合位移和应力边界条件,推导了无限均匀弹性介质中任意分布的多个弹性圆柱体对于平面水平向剪切波(SH波)入射时散射系数的理论解析解。随后,取圆柱体分布于两条相互平行的直线上,则问题演变为双排弹性桩屏障对于弹性波的隔离问题。引入无量纲位移(屏障后土体总的位移与仅由入射平面水平向剪切波引起的位移的比值)和透射系数(屏障宽度范围内无量纲位移的几何平均值)的概念来研究屏障的隔振效果。重点讨论了双排桩间距h以及桩土的剪切模量比ξ对于屏障整体隔振效果的影响,阐述了双排桩屏障的隔振性状。特别地,当h=0时,该问题退化为常见的单排非连续屏障的隔振问题。  相似文献   

矢量空间数据渐进传输研究进展     

温永宁  闾国年  陈旻 《地理与地理信息科学》2011,27(6):6-12,40

渐进传输被认为是解决目前海量空间数据传输与实时用户体验之间矛盾的有效方法。栅格数据渐进传输的相关研究比较成熟,但矢量数据的渐进传输理论和技术还存在问题。为了推进矢量数据渐进传输的相关研究,该文对与矢量数据渐进传输密切相关的二维矢量数据、三维表面模型两种数据的多分辨率表达和渐进传输的研究现状进行归纳与总结,指出相关研究的发展方向,为海量空间数据适用于分布式网络传输提供参考依据。  相似文献   

An empirical formula for friction coefficient of a perforated wall with vertical slits     

Kyung-Duck Suh  Yeul Woo KimChang-Hwan Ji 《Coastal Engineering》2011

The friction coefficient in the permeability parameter of a perforated wall has been estimated on the basis of a best fit between measured and predicted values of such hydrodynamic coefficients as reflection and transmission coefficients. In the present study, an empirical formula for the friction coefficient is proposed in terms of known variables, i.e., the porosity and thickness of the perforated wall and the water depth. This enables direct estimation of the friction coefficient without invoking a best fit procedure. To obtain the empirical formula, hydraulic experiments are carried out, the results of which are used along with other researchers' results. The proposed formula is used to predict the reflection and transmission coefficients of various types of structures including a perforated wall. The concurrence between the experimental data and calculated results is good, verifying the appropriateness of the proposed formula. It is also shown that the proposed formula can be used for irregular waves as well.  相似文献   

Experimental researches on reflective and transmitting performances of quarter circular breakwater under regular and irregular waves   总被引：1，自引：1，他引：0  

史艳娇  吴米玲  蒋学炼  李炎保 《中国海洋工程》2011,25(3):469-478

A series of regular and irregular wave experiments are conducted to study the reflective and transmitting performances of quarter circular breakwater (QCB) in comparison with those of semi-circular breakwater (SCB). Based on regular wave tests, the reflection and transmission characteristics of QCB are analyzed and a few influencing factors are investigated. Then, the wave energy dissipation as wave passing over the breakwater is discussed based on the hydraulic coefficients of QCB and SCB. In irregular wave experiments, the reflection coefficients of QCB and their spectrums are studied. Finally, the comparisons between the experimental results and numerical simulations for QCB under regular and irregular wave conditions are presented.  相似文献   

用于复合驱防腐垢剂的综合性能评价     

孟祥海  张云宝 《海洋地质译丛》2011,(3):45-49

适合于复合驱的防腐垢剂BH是一种磷硅酸盐。针对矿场实际,通过室内实验,对含该防腐垢剂的三元复合体系基本性质进行了研究。结果表明,这种磷硅酸盐防腐垢剂具有良好的缓蚀防垢效果,且驱油体系与渤海油田原油仍然可以形成超低界面张力。体系的表观黏度和界面张力的稳定性也有所改善。压力传导和转向调44能力实验结果表明：“聚合物／BH助剂”和“聚合物／表面活性剂／BH助剂”复合体系相比聚合物溶液其传导能力分别下降了14．2％和29．5％,转向调剖能力分别提高了11．8％和14．9％;而“聚合物／ga活性剂／BH助剂”相比“聚合物／表面活性剂／NaOH”体系传导能力相差不大,但转向调剖能力相对提高了10％左右。可见BH防腐垢剂不仅具有良好的缓蚀防垢和降低界面张力效果,而且具有较强的转向调剖能力。  相似文献