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一种基于边缘点特征与矢量特征的人体掌形认证算法
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作者 张雪飞 李欣 董静薇 《哈尔滨理工大学学报》 CAS 2008年第4期4-6,共3页
提出了一种将掌形边缘点特征与矢量特征相结合的人体掌形认证算法.该算法将两种特征有机地结合在一起,降低了对手指摆放位置的要求,摆脱了传统掌形仪需要固定栓的限制,同时提高了掌形认证的准确度.使未来掌形仪的设计更加灵活,更加人性化.
关键词 人体掌形认证 边缘点特征 失量特征
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一种融和特征矢量与边缘点特征的掌形认证方法 被引量:1
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作者 李欣 张雪飞 《哈尔滨理工大学学报》 CAS 2008年第5期25-27,共3页
针对常用的两种掌形认证方法(特征矢量法、边缘点特征法)中存在的误受率高、运算量大等问题,提出了手指左、右半轴宽度概念,可将上述两种方法的优点有机结合起来,有效克服了两种方法中各自的缺陷,在与特征矢量法运算量相近的前提下,可... 针对常用的两种掌形认证方法(特征矢量法、边缘点特征法)中存在的误受率高、运算量大等问题,提出了手指左、右半轴宽度概念,可将上述两种方法的优点有机结合起来,有效克服了两种方法中各自的缺陷,在与特征矢量法运算量相近的前提下,可以保证误受率和误拒率都较低.由于本方法是针对多个手指进行认证的,可以降低对手指摆放位置的要求,可以取消目前掌形仪中的固定栓,使认证过程更方便和人性化,使未来掌形仪的设计更加灵活. 展开更多
关键词 人体掌形认证 特征 边缘点特征
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The effects of vegetation on runoff and soil loss:Multidimensional structure analysis and scale characteristics 被引量:10
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作者 刘见波 高光耀 +3 位作者 王帅 焦磊 伍星 傅伯杰 《Journal of Geographical Sciences》 SCIE CSCD 2018年第1期59-78,共20页
This review summarizes the effects of vegetation on runoff and soil loss in three dimensions: vertical vegetation structures(aboveground vegetation cover, surface litter layer and underground roots), plant diversity, ... This review summarizes the effects of vegetation on runoff and soil loss in three dimensions: vertical vegetation structures(aboveground vegetation cover, surface litter layer and underground roots), plant diversity, vegetation patterns and their scale characteristics. Quantitative relationships between vegetation factors with runoff and soil loss are described. A framework for describing relationships involving vegetation, erosion and scale is proposed. The relative importance of each vegetation dimension for various erosion processes changes across scales. With the development of erosion features(i.e., splash, interrill, rill and gully), the main factor of vertical vegetation structures in controlling runoff and soil loss changes from aboveground biomass to roots. Plant diversity levels are correlated with vertical vegetation structures and play a key role at small scales, while vegetation patterns also maintain a critical function across scales(i.e., patch, slope, catchment and basin/region). Several topics for future study are proposed in this review, such as to determine efficient vegetation architectures for ecological restoration, to consider the dynamics of vegetation patterns, and to identify the interactions involving the three dimensions of vegetation. 展开更多
关键词 RUNOFF soil loss vertical vegetation structure plant diversity vegetation pattern scale characteristics
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