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921.
床面冲淤计算机处理方法 总被引:2,自引:0,他引:2
冲淤计算是河流,河口,海岸等水域中分析,预测床面变化的基础,利用非结构网络自动剖分技术形成覆盖计算区域的三角网,能较好地适应边界和特殊地形,基于高程内插建立三角网数字高程模型,采用垂直三棱柱体作为基本单位计算不同时段冲淤量,从而提高计算精度,通过网络剖分,利用在计算区域内任意选择子域进行淤量的计算和分析。同时将生成的非结构网格直接有于二维床面冲淤数学模型,便于对每个节点的计算结果进行检证以提高模型的可靠性。 相似文献
922.
In this paper, image processing technique that reduces video images of buoy motion to yield time series of image coordinates
of buoy objects will be investigated. The buoy motion images are noisy due to time-varying brightness as well as non-uniform
background illumination. The occurrence of boats, wakes, and wind-induced white caps interferes significantly in recognition
of buoy objects. Thus, semiautomated procedures consisting of object recognition and image measurement aspects will be conducted.
These offer more satisfactory results than a manual process. Spectral analysis shows that the image coordinates of buoy objects
represent wave motion well, indicating its usefulness in the analysis of wave characteristics. 相似文献
923.
Marine seismic data has been collected for several decades in both academia and industry. Early single channel acquisitions
were often, if at all, recorded on magnetic media that are generally no longer supported for replay. Although seismic data
over 10 years old has limited quality compared to modern acquisition, thousands of survey km of hard copy records remains
world wide in areas with no recent coverage. In addition, many processed multi-channel datasets are now not available as digital
files for a variety of reasons. Rising interest in continental margin geology in response to climate change priorities and
the UNCLOS submission requirements of maritime states has created a demand to re-use these older records where the cost of
new or re-acquisition is not pragmatic. Through creating digital SEG-Y files from images of these records they can be reprocessed
and re-interpreted. This paper investigates the practicalities of paper seismic record re-use and measures the performance
of a typical conversion option as an indicator of the validity of the concept. Examples of applications of the process illustrate
what can be achieved and the limitations that exist so that users can make an informed choice of whether to resurrect their
information. 相似文献
924.
925.
新型船载气象卫星接收系统 总被引:8,自引:0,他引:8
新型船载气象卫星接收系统为南极考察船的航海气象保障和在南大洋冰区中航行导航专门研制.该系统能够适应高温、高湿和低温超饱和的气候环境,在12级以上大风和船在破冰时剧烈摇摆和振动以及有雷达等强磁场信号干扰的情况下,具有自我保护能力.有极轨高分辨和静止低分辨卫星的双套接收和图像处理系统.该系统的关键创新之处:(1)采用了有源陀螺仪稳定平台.利用惯性测量和三轴伺服机构控制天线和隔离船摇.解决极轨卫星低仰角和过顶轨道高仰角跟踪丢线的矛盾,解决了船在运动状态下,不断改变位置、方向以及摇摆的状态下,准确地跟踪和捕捉到卫星,接收到清晰的卫星云图.(2)图像处理系统用了最新的BORLAND-DELPHI语言编程,采用两行元素的轨道模式计算动态定位套网格系统.利用电子地图网格数据,用迭代法画出地形海岸线.计算出每一像元素的位置;能够在图上显示任意一点的经纬度,标出任意目标物.解决了在海洋中航行找不到参照物时的困惑.能够监测云和温度、林火、海洋及陆地的异常变化.能够输出24位真彩色的高清晰度的卫星云图.该系统整体结构技术先进,体积小,重量轻,适应恶劣气候和海洋环境,图像处理系统功能齐全、分辨率高,操作方便.既适用于各种船只,也适用于陆地. 相似文献
926.
This policy brief is a summary product of seven case studies examining the integration of local ecological knowledge in fisheries management. Each case began with a series of in-depth interviews with local fishers, after which their answers were examined using both social and biological approaches to assess the possibility of using the information as the basis of simple, valid and locally acceptable indictors for fisheries management. We found that allocation and knowledge issues are closely interlinked and must be addressed in concert, and that the negotiation of shared understandings between multiple sources of knowledge must be a continuous process within an adaptive framework rather than a question of identifying a fixed set of indicators. 相似文献
927.
Past research suggests that how we perceive risk can be related to how we attribute responsibility for risk-related issues, such as climate change; however, a gap in research lies in exploring possible connections between attribution of responsibility, risk perception, and information processing. Using the Risk Information Seeking and Processing model, this study fills this gap by examining how RISP-based variables are related to information processing and whether attribution of responsibility for mitigating climate change influences communication behaviors that are often predicted by elevated risk perceptions. Undergraduates at two large research universities (N = 572) were randomly assigned to read one of two newspaper articles that emphasized either individual responsibility (by highlighting personal actions) or societal responsibility (by highlighting government policy) for climate change mitigation. Results indicate that subjects in the individual responsibility condition were significantly more likely to process the message in a systematic manner; however, attribution of responsibility did not interact with risk perception to influence systematic processing. Moreover, attitudes toward climate change information and negative affect mediated the relationship between other key variables and systematic processing. These and other findings suggest that strategic communication about climate change may benefit from emphasizing individual responsibility to attract more attention from diverse audiences and to promote deeper thinking about the issue. Additional theoretical implications are presented. 相似文献
928.
采用VAP(Velocity Azimuth Processing)方法反演多普勒雷达风矢量场,在利用各个距离圈径向速度随方位角分布的廓线推算风向和风速的设计中,要求基数据速度资料中没有明显的脉动.介绍了在多普勒天气雷达风场反演设计中,直接将方格法的速度资料处理过程融入到方格法风场反演的过程中,利用距离方格内保持中尺度特性的特点,不改变原始资料的同时保证风场反演的正确性. 相似文献
929.
利用Excel的数据处理功能以及自带的"Visual Basic "语言进行二次开发,然后以宏的形式连接在Excel界面上,实现了形变观测数据的处理. 相似文献
930.