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81.
数字水印技术与算法实现   总被引:6,自引:0,他引:6  
综述了数字水印技术的起源、概念、特点和应用;提出了数字水印处理技术的基本框架;列出了一些主要的基于图像的水印嵌入算法和水印检测算法;并展望了水印处理技术的未来发展趋势;最后给出了一种基于DCT变换的水印嵌入与检测算法。  相似文献   
82.
为解决目前医院地理信息服务系统在信息共享、空间分析等方面的不足,采用ArcGIS Server组件、C#编程语言、SQL Server数据库研发了医院网络地理信息服务系统。该系统以天地图作为基础地理数据,融合医院空间与医疗信息,并部署到互联网环境中。除具有医疗专题信息的网络浏览与查询外,系统还实现了诸多空间分析、地学统计等功能,既可为市民就医提供更全面的信息查询,又可为医疗事故的突发与应急提供技术支撑。  相似文献   
83.
随着卫星影像技术和计算机技术的不断发展,人类已进入了数字化的信息时代,卫星影像具有测量精度高、现势性好、分辨率高、信息丰富、直观真实且具有良好的可判读性和可量测性的特点,在人们生产生活中的应用也较为广泛,具有十分广阔的应用潜力。本文论述了卫星影像DOM技术在生产以及检查中的应用。  相似文献   
84.
This paper describes the structure, geometric model and geometric calibration of Photogrammetron I—the first type of photogrammetron which is designed to be a coherent stereo photogrammetric system in which two cameras are mounted on a physical base but driven by an intelligent agent architecture. The system calibration is divided into two parts: the in-lab calibration determines the fixed parameters in advance of system operation, and the in-situ calibration keeps tracking the free parameters in real-time during the system operation. In a video surveillance set-up, prepared control points are tracked in stereo image sequences, so that the free parameters of the system can be continuously updated through iterative bundle adjustment and Kalman filtering.  相似文献   
85.
This paper presents a conceptual data model, the STA-model, for handling spatial, temporal and attribute aspects of objects in GIS. The model is developed on the basis of object-oriented modeling approach. This model includes two major parts: (a) modeling the signal objects by STA-object elements, and (b) modeling relationships between STA-objects. As an example, the STA-model is applied for modeling land cover change data with spatial, temporal and attribute components.  相似文献   
86.
This paper presents the hypermedia data model based on the infinity RS image information system we have developed. The hypermedia data model consists of different semantic units called nodes, and the associations between nodes are called links. This paper proposes three kinds of nodes (interior node, physical node and complex node) and two kinds of links (plane network structure link, hyper-cube network structure links). The hypermedia information system, based on the model and the basic data layer (the infiniy RS image), represents a digital globe. An approach to the “Getting Lost in the Hyper-space” problem is presented. The approach using the hypermedia data model is an efficient way of handling a large number of RS images in various geographical information systems.  相似文献   
87.
Point set generalization is one of the essential problems in map generalization. On the demands analysis of point set generalization, this paper proposes a method to generalize point sets based on the Kohonen Net model; the standard SOM algorithm has been improved so as to preserve the spatial distribution properties of the original point set. Examples illustrate that this method suits the generalization of point sets.  相似文献   
88.
Abstract

</p>Gamepads and joysticks have the potential to improve spatial navigation in virtual globes, block diagrams and 2D maps. Digital school atlases, in particular, can become more engaging if support for gamepads and joysticks is added, as children and adolescents are very proficient at using these devices. The fusion of gaming devices and interactive school atlases offers interesting new use cases: teachers can control a digital wall map with a remote-control gamepad while lecturing from the front of the classroom, or students can explore maps on their personal computers using an enticing way to interact. This paper presents these use cases, the characteristics of the most common gaming devices, and discusses spatial navigation with gamepads and joysticks for globes, block diagrams and 2D maps. The ideas presented originated from the ongoing development of a new, interactive version of the Swiss World Atlas for schools.  <a href="relate_search.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=A41A70F4AB56AB1B&aid=5A172168B32099AE544AB8BD3EC6ADF4&language=1&ctl=0&etl=29" target="_blank">相似文献</a>    </div> <div></div> <div class="clear"></div> </div> <div class="clear"></div> </div> <div class="search_article"> <div class="search_articleleft">89.</div> <div class="search_articleright"> <div> <a class="a1" href="https://td.alljournals.cn/view_abstract.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&aid=E21E6737789C2A77CDEA14F652F3DA65" target="_blank">Generation and study of satellite gravity over Gujarat,India and their possible correlation with earthquake occurrences</a>   <em><strong></strong></em>   </div> <div> <a href="search.aspx?subject=astronomy_earth_science&major=chx&field=author_name&encoding=utf-8&q=T.+J.+Majumdar" target="_blank">T. J. Majumdar</a>  <a href="search.aspx?subject=astronomy_earth_science&major=chx&field=author_name&encoding=utf-8&q=R.+Bhattacharyya" target="_blank">R. Bhattacharyya</a> <a class="a2" href="#">《国际地球制图》</a>2013,28(4):269-280 </div> <div>High-resolution satellite gravity data have been generated and utilized to infer subsurface geological structures in the area of devastating earthquake that struck the Bhuj region in Gujarat on 26 January 2001. Latitudinal gravity profiles have been generated in the Bhuj, Anjar and IBF regions across the epicentres (23.5° N, 69.8° E/M<sub>w</sub> 7.0 in 2001; 23.2° N, 70° E/M<sub>w</sub> 7.0 in 1956; 24.2° N, 69.2° E/M<sub>w</sub> 7.8 in 1819). Substantial differences in gravity anomaly patterns as high as 37 mGal could be observed existing near the epicentre regions. These gravitational differences might have caused due to the plate tectonic processes and due to the changes in densities of different lithospheric zones/sedimentary layers. Temporal variations of the satellite-derived gravity and their probable relations with already occurred major earthquakes in this region have been studied. Hence we conclude that drastic changes in gravity anomalies can be considered as a precursor for occurrences of substantially large earthquakes.  <a href="relate_search.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=A41A70F4AB56AB1B&aid=E21E6737789C2A77CDEA14F652F3DA65&language=1&ctl=0&etl=119" target="_blank">相似文献</a>    </div> <div></div> <div class="clear"></div> </div> <div class="clear"></div> </div> <div class="search_article"> <div class="search_articleleft">90.</div> <div class="search_articleright"> <div> <a class="a1" href="https://td.alljournals.cn/view_abstract.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&aid=94CB1CF5420CA8621FC2B6C9EFDA4DFC" target="_blank">规则格网DEM地形综合方法分析</a>   <em><strong></strong></em>   </div> <div> <a href="search.aspx?subject=astronomy_earth_science&major=chx&field=author_name&encoding=utf-8&q=%e5%be%90%e9%9d%99" target="_blank">徐静</a>  <a href="search.aspx?subject=astronomy_earth_science&major=chx&field=author_name&encoding=utf-8&q=%e9%a1%be%e7%95%99%e7%a2%97" target="_blank">顾留碗</a>  <a href="search.aspx?subject=astronomy_earth_science&major=chx&field=author_name&encoding=utf-8&q=%e5%bc%a0%e8%80%80%e6%b0%91" target="_blank">张耀民</a>  <a href="search.aspx?subject=astronomy_earth_science&major=chx&field=author_name&encoding=utf-8&q=%e9%9f%a9%e5%85%89%e8%be%89" target="_blank">韩光辉</a> <a class="a2" href="#">《测绘工程》</a>2014,23(9):26-31 </div> <div>针对当前丰富多样的DEM地形综合模型,分类阐述其综合原理、关键技术及优缺点,以黄土丘陵1:1万DEM为基础,对其地形综合效果进行对比分析。研究结果表明:现有的DEM地形综合模型各有优缺点;不同综合模型综合后的地形,高程数值随着综合尺度的增加,存在显著差异,而且不同综合模型对流域边界的综合处理也存在显著差异,没有形成客观有效的流域边界描述;当前困扰DEM地形综合的关键问题,是缺乏不同尺度下地形综合质量的客观评价标准,致使现有综合模型地形综合结果和DEM格网分辨率之间没有建立本应存在的内在联系,有待进一步深入研究。  <a href="relate_search.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=A41A70F4AB56AB1B&aid=94CB1CF5420CA8621FC2B6C9EFDA4DFC&language=2&ctl=15&etl=47" target="_blank">相似文献</a>    </div> <div></div> <div 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