Water quality assessment for Ulansuhai Lake using fuzzy clustering and pattern recognition   总被引：1，自引：0，他引：1  

任春涛  李畅游  贾克力  张生  李卫平  曹有玲 《中国海洋湖沼学报》2008,26(3):339-344

Water quality assessment of lakes is important to determine functional zones of water use. Considering the fuzziness during the partitioning process for lake water quality in an arid area, a multiplex model of fuzzy clustering with pattern recognition was developed by integrating transitive closure method, ISODATA algorithm in fuzzy clustering and fuzzy pattern recognition. The model was applied to partition the Ulansuhai Lake, a typical shallow lake in arid climate zone in the west part of Inner Mongolia, China and grade the condition of water quality divisions. The results showed that the partition well matched the real conditions of the lake, and the method has been proved accurate in the application.  相似文献   

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王穗辉  潘国荣 《大地测量与地球动力学》2008,28(1):59-64

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基于端元独立性的端元数目自动获取方法     

齐建成  朱述龙  朱宝山  曹闻 《测绘科学》2009,34(6)

目前端元数目主要是图像处理者目视判读影像获得的经验值,往往与影像中实际典型地物种类数目不符合。根据端元数目取值不同时的分类结果均方根误差(RMSE)的大小,能够得到实际端元数,但该方法因多次分类导致计算量过大。本文在研究端元间光谱相关性与端元数目之间关系的基础上,提出一种基于端元独立性的端元数目自动获取方法。与基于RMSE的端元数目自动获取方法的对比实验表明,该方法不仅能够正确有效地获取实际端元数,提高端元提取自动化程度,而且能够大大减少运算时间。  相似文献   

1：50000 DLG数据质量检查软件     

张明灯  左志进 《地理空间信息》2009,7(3):27-29

简要介绍了1：50000 DLG数据质量的重要性以及研究DLG数据质量检查软件的必要性。对1：50000 DLG数据质量检查软件的结构、功能进行了总体设计，对软件功能实现的关键算法做了详细阐述。  相似文献   

城市暴雨积水模拟方法分析及研究   总被引：4，自引：0，他引：4  

杨弋  吴升 《测绘信息与工程》2009,34(1):35-37

在总结目前常用城市暴雨积水模拟方法的基础上，从水体由高到低的运动机理着手，将基于数字地形分析技术的路径算法引入城市暴雨积水模拟，并考虑到管网汇流及城市地形因素，给出数据修正与算法改进的具体方法。  相似文献   

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潘国荣  谷川  王穗辉  蔡润彬 《大地测量与地球动力学》2009,29(1):57-63

???????????????д???????????????????????????????????н??????????????????Щ?????????????????????????д?????????????????????Ч????????????????????????е??????????????RANSAC????????????н???????????????????Ч???????????????н?????????????????????????????????????????????????????????????????????????????????????  相似文献   

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闫丽丽  高井祥  孙久运 《大地测量与地球动力学》2009,29(4):116-119

?????е???α???????λ???????и???????????μ???????????С????????????λ???????????????λ?????????????????????????????????????????????μ?????????????????????????????1??75???????￡??μ??λ????????????λ?????и???????????????????????10?????????0.02???????????  相似文献   

SA算法优化BP神经网络应用于GPS高程拟合     

彭友志  罗登贵  张雄 《地理空间信息》2009,7(1):106-108

BP神经网络算法用于高程拟合有训练速度慢和易于陷入局部最小值的缺点，基于BP算法学习特点，模拟退火算法（SA）在局部极小处的概率突变性，本文作者有效结合BP和SA算法，提出一种SA优化BP神经网络算法的BPSA混合学习策略，并以实例验证了该算法的有效性。  相似文献   

自动综合算法库的构建     

钱海忠 《测绘科学》2009,34(6)

要提高自动综合的自动化水平,不但要开发自动化、智能化程度高的自动综合算法,同时需要对自动综合算法进行有效地管理和使用。目前国内外研究重点在于前者,而对后者研究较少。本文提出了自动综合算法元数据的概念,并从自动综合算法的适用范围、算法功能、算法参数等关键信息,以及算法基本信息、经验信息、改进信息和综合评价指标等辅助信息,以及自动综合算法优先权等方面着手,分步骤、分层次地设计并构建了自动综合算法的元数据管理体系,从而实现了方便、有效地管理与调用自动综合算法,为提高自动综合的自动化程度和水平提供了有力支持。  相似文献   

一个从基于位置相关服务而收集的零星位置点中获取连续车辆轨迹的方法(英文)   总被引：1，自引：1，他引：0  

李响  张喜慧  林珲 《地球空间信息科学学报》2009,12(2):85-94

The paper proposes an economical and fast algorithm for deriving trajectories from sporadic tracking points collected in location-based services (LBS). Although many traffic studies or applications can benefit from the derived trajectories, the sporadic tracking points are always implicitly overlooked by most of existing map-matching algorithms. The algorithm proposed in this paper finds network paths or trajectories traveled by vehicles through augmenting GPS data with odometer data. An odometer can provide data of traveled distance which are compared with the lengths of candidate network paths in order to find the most approximate network path approaching the trajectory of a vehicle. Tracking points are classified into anchor points and non-anchor points. The former are used to divide trajectories, and the latter screen candidate network paths. An elliptic selection zone and a reduction process are applied to the selection of possible road segments composing candidate network paths. A brute-force searching algorithm is developed to find candidate network paths and calculate their lengths. A two-step screening process is designed to select the final result from candidate network paths. Finally, a series of experiments are conducted to validate the proposed algorithm. Supported by the National Natural Science Foundation of China (No.40701142), the Scientific Research Starting Foundation for Returned Overseas Chinese Scholars, Ministry of Education, China.  相似文献