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扩展相似度空间的案例推理故障恢复方法
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作者 李团结 王飞军 严天宏 《西安电子科技大学学报》 EI CAS CSCD 北大核心 2008年第3期499-503,共5页
结合LID算法和CMM方法,提出了基于扩展相似度空间的案例推理多机器人系统故障恢复方法.其核心思想是通过故障特征提取错误节点,进而得到错误节点的扩展相似度空间,然后在扩展相似度空间范围内,直接按错误节点发生概率的大小推测故障.该... 结合LID算法和CMM方法,提出了基于扩展相似度空间的案例推理多机器人系统故障恢复方法.其核心思想是通过故障特征提取错误节点,进而得到错误节点的扩展相似度空间,然后在扩展相似度空间范围内,直接按错误节点发生概率的大小推测故障.该方法不必严格依节点深度递进的次序推测故障,揭示了某些故障具有自然多发性的事实.给出了扩展相似度空间方法的推理模型和算法流程,并进行了实例仿真.结果表明扩展相似度空间方法的平均推测次数少于LEAF方法,缩短了多机器人系统故障恢复时间. 展开更多
关键词 扩展相似度空间方法 案例推理 故障恢复 错误节点 多机器人系统
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基于相似度空间寻优的开集人脸识别方法
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作者 张凯 《微型电脑应用》 2010年第6期31-32,44,共3页
提出了一种对相似度空间进行寻优的新方法,以提高开集人脸识别的准确率。该方法首先将开集识别问题转化为二分类问题,然后引入寻优方法寻找分割相似度空间的最优超平面,该超平面能够将相似度空间分割为接受空间和拒绝空间两部分。在判... 提出了一种对相似度空间进行寻优的新方法,以提高开集人脸识别的准确率。该方法首先将开集识别问题转化为二分类问题,然后引入寻优方法寻找分割相似度空间的最优超平面,该超平面能够将相似度空间分割为接受空间和拒绝空间两部分。在判别过程中,利用相似度向量在空间中的位置判断样本是否为已知类。由于利用了相似度空间中向量分布的信息,训练出的特征具有更强的分类能力。通过不同人脸库的实验表明,相对于传统的方法,本文所提的方法能显著地提高开集识别的准确率。 展开更多
关键词 人脸识别 开集 相似度空间
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Spatial and temporal variation of fish assemblages in a subtropical small stream of the Huangshan Mountain 被引量:12
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作者 Yunzhi YAN Shan HE +3 位作者 Ling CHU Xiuying XIANG Yanju JIA Juan TAO 《Current Zoology》 SCIE CAS CSCD 北大核心 2010年第6期670-677,共8页
Spatial and temporal variation of fish assemblages were investigated seasonally from May 2007 to February 2008 across 11 study sites in a subtropical small stream, the Puxi Stream, of the Huangshan Mountain. Along the... Spatial and temporal variation of fish assemblages were investigated seasonally from May 2007 to February 2008 across 11 study sites in a subtropical small stream, the Puxi Stream, of the Huangshan Mountain. Along the longitudinal gradient from headwater to downstream, fish species richness and abundance increased gradually, but then decreased significantly at the lower reaches. The highest species richness and abundance were observed in August and the lowest in February. Based on analysis of similarities (ANOSIM), fish assemblages were significantly different in spatial variation but not in temporal variation. Although differences were observed both among sites and among stream orders, the lower R value in order-variation suggested stream order was not the optimal factor explaining the spatial variation of fish assemblages. In addition, dam construction did not significantly alter fish assemblages in the sites adjacent to and immediately downstream to dams. Using cluster analysis and non-metric Multi Dimensional Scaling analysis (NMS), assemblages were separated into three groups at a Bray-Curtis similarity value of 42%: the upper, middle and lower groups. Following analysis of similarity percentages of species contributions (SIM- PER), shifts in occurrence or abundance of S. curriculus, Z. platypus, R. bitterling and A. fasciatus contributed most to the differences amongst the three groups. Standard Deviation Redundancy Analysis (RDA) suggested that habitat structure (such as elevation, substrate, and flow velocity) contributed to the spatial and temporal pattem of fish assemblages in the Puxi Stream. In conclusion, the fish assemblages in Puxi Stream presented significant spatial but not temporal variation. Human disturbance has perhaps induced the decrease in species diversity in the lower reaches. However, no significant change was observed for fish assemblages in sites far from and immediately downstream from low-head dams [Current Zoology 56 (6): 670-677, 2010]. 展开更多
关键词 Assemblage structure Low-head dam Stream fish Spatial-temporal pattem
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Fundamental Theories of Spatial Similarity Relations in Multi-scale Map Spaces 被引量:18
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作者 YAN Haowen 《Chinese Geographical Science》 SCIE CSCD 2010年第1期18-22,共5页
Similarity relation is one of the spatial relations in the community of geographic information science and cartography.It is widely used in the retrieval of spatial databases, the recognition of spatial objects from i... Similarity relation is one of the spatial relations in the community of geographic information science and cartography.It is widely used in the retrieval of spatial databases, the recognition of spatial objects from images, and the description of spatial features on maps.However, little achievements have been made for it by far.In this paper, spatial similarity relation was put forward with the introduction of automated map generalization in the construction of multi-scale map databases;then the definition of spatial similarity relations was presented based on set theory, the concept of spatial similarity degree was given, and the characteristics of spatial similarity were discussed in detail, in-cluding reflexivity, symmetry, non-transitivity, self-similarity in multi-scale spaces, and scale-dependence.Finally a classification system for spatial similarity relations in multi-scale map spaces was addressed.This research may be useful to automated map generalization, spatial similarity retrieval and spatial reasoning. 展开更多
关键词 similarity relation spatial relation multi-scale map spaces
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