Aiming to deal with the difficult issues of terrain data model simplification and crack disposal,the paper proposed an improved level of detail(LOD)terrain rendering algorithm,in which a variation coefficient of eleva...Aiming to deal with the difficult issues of terrain data model simplification and crack disposal,the paper proposed an improved level of detail(LOD)terrain rendering algorithm,in which a variation coefficient of elevation is introduced to express the undulation of topography.Then the coefficient is used to construct a node evaluation function in the terrain data model simplification step.Furthermore,an edge reduction strategy is combined with the improved restrictive quadtree segmentation to handle the crack problem.The experiment results demonstrated that the proposed method can reduce the amount of rendering triangles and enhance the rendering speed on the premise of ensuring the rendering effect compared with a traditional LOD algorithm.展开更多
为了提高浅海环境监测的及时性和避免人为主观评价水质的不合理性,引入窄带物联网(Narrow Band Internet of Things, NB-IoT)多节点方式进行浅海环境参数回传,并在远程端使用数据融合技术对其进行融合处理,实现水质等级科学评价。采用...为了提高浅海环境监测的及时性和避免人为主观评价水质的不合理性,引入窄带物联网(Narrow Band Internet of Things, NB-IoT)多节点方式进行浅海环境参数回传,并在远程端使用数据融合技术对其进行融合处理,实现水质等级科学评价。采用两级并联融合方式进行环境参数融合,在融合前使用模糊理论中的相关性函数剔除外界及传感器本身噪声所造成的异常数据;然后使用自适应加权融合算法对其进行第一级融合,最后运用模糊综合评价方法将上一级的融合结果进行决策层融合,实现浅海环境的水质等级评价。经试验验证,使用上述方法能够更加及时、有效地获取水质环境参数且第一级融合相对误差小于6.5%,并能以概率形式直观展现出监测区域的水质等级,提高水质等级评价的准确性与可靠性。展开更多
基金Supported by the National Natural Science Foundation of China(61363075)the National High Technology Research and Development Program of China(863 Program)(2012AA12A308)the Yue Qi Young Scholars Program of China University of Mining&Technology,Beijing(800015Z1117)
文摘Aiming to deal with the difficult issues of terrain data model simplification and crack disposal,the paper proposed an improved level of detail(LOD)terrain rendering algorithm,in which a variation coefficient of elevation is introduced to express the undulation of topography.Then the coefficient is used to construct a node evaluation function in the terrain data model simplification step.Furthermore,an edge reduction strategy is combined with the improved restrictive quadtree segmentation to handle the crack problem.The experiment results demonstrated that the proposed method can reduce the amount of rendering triangles and enhance the rendering speed on the premise of ensuring the rendering effect compared with a traditional LOD algorithm.
文摘为了提高浅海环境监测的及时性和避免人为主观评价水质的不合理性,引入窄带物联网(Narrow Band Internet of Things, NB-IoT)多节点方式进行浅海环境参数回传,并在远程端使用数据融合技术对其进行融合处理,实现水质等级科学评价。采用两级并联融合方式进行环境参数融合,在融合前使用模糊理论中的相关性函数剔除外界及传感器本身噪声所造成的异常数据;然后使用自适应加权融合算法对其进行第一级融合,最后运用模糊综合评价方法将上一级的融合结果进行决策层融合,实现浅海环境的水质等级评价。经试验验证,使用上述方法能够更加及时、有效地获取水质环境参数且第一级融合相对误差小于6.5%,并能以概率形式直观展现出监测区域的水质等级,提高水质等级评价的准确性与可靠性。
