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青城山森林群落的数量分类 被引量:5
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作者 马丹炜 邹琴 《四川师范大学学报(自然科学版)》 CAS CSCD 2003年第1期74-78,共5页
以森林植被样地中乔木层树种的重要值为指标,采用群落相似系数分类法、最近邻体法、组平均法对青城前山森林植被样地进行数量分类.3种分类法的结果表明,所调查的11个森林植被的样地分为2个植被亚型5个群系.常绿阔叶林中的各个群系基本... 以森林植被样地中乔木层树种的重要值为指标,采用群落相似系数分类法、最近邻体法、组平均法对青城前山森林植被样地进行数量分类.3种分类法的结果表明,所调查的11个森林植被的样地分为2个植被亚型5个群系.常绿阔叶林中的各个群系基本处于稳定阶段,仅有个别样地受到人类的轻度干扰,一些阳生性的落叶成分侵入群落内,群落表现出明显的次生性质,但是,目前落叶成分在群落中缺乏更新幼苗,若加强森林管理,群落将会恢复其原生状态;杉木群系主要分布在人为影响较大的常绿阔叶林的林缘地带,由于许多常绿树种已进入群落的最高层造成遮荫,杉木在林内生长状况不良,群落最终将演替为常绿阔叶林. 展开更多
关键词 森林群落 青城山 数量分类 森林植被 群落生态学 群落相似系数分类法 最近邻体法
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利用计算机视觉识别茶叶的色泽类型 被引量:45
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作者 陈全胜 赵杰文 +1 位作者 张海东 方明 《江苏大学学报(自然科学版)》 EI CAS 北大核心 2005年第6期461-464,共4页
针对茶叶色泽的感官评定存在识别结果的主观性强和一致性差等缺点,提出了一种新的识别方法,在计算机视觉技术定量描述茶叶的颜色特征的基础上,根据相似分类法(SIMCA)模式识别原理分别为碧螺春、龙井和祁红等三种茶叶建立了各自的分类识... 针对茶叶色泽的感官评定存在识别结果的主观性强和一致性差等缺点,提出了一种新的识别方法,在计算机视觉技术定量描述茶叶的颜色特征的基础上,根据相似分类法(SIMCA)模式识别原理分别为碧螺春、龙井和祁红等三种茶叶建立了各自的分类识别模型并进行识别.结果显示在显著性水平α=5%的条件下,所建立的模型最佳;训练时,各自模型对己类样本的回判率和对非己类样本的拒绝率都达到100%;预测时,各自模型对己类样本的识别率分别为90%、90%和100%,对非己类样本的拒绝率都是100%.试验结果表明,利用计算机视觉技术识别茶叶的色泽类型是可行的. 展开更多
关键词 茶叶色泽 识别 计算机视觉 相似分类法
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Clustering analysis algorithm for security supervising data based on semantic description in coal mines 被引量:1
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作者 孟凡荣 周勇 夏士雄 《Journal of Southeast University(English Edition)》 EI CAS 2008年第3期354-357,共4页
In order to mine production and security information from security supervising data and to ensure security and safety involved in production and decision-making,a clustering analysis algorithm for security supervising... In order to mine production and security information from security supervising data and to ensure security and safety involved in production and decision-making,a clustering analysis algorithm for security supervising data based on a semantic description in coal mines is studied.First,the semantic and numerical-based hybrid description method of security supervising data in coal mines is described.Secondly,the similarity measurement method of semantic and numerical data are separately given and a weight-based hybrid similarity measurement method for the security supervising data based on a semantic description in coal mines is presented.Thirdly,taking the hybrid similarity measurement method as the distance criteria and using a grid methodology for reference,an improved CURE clustering algorithm based on the grid is presented.Finally,the simulation results of a security supervising data set in coal mines validate the efficiency of the algorithm. 展开更多
关键词 semantic description clustering analysis algorithm similarity measurement
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今天我到哪儿去?
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作者 Michael J.Miller 李江卫 《个人电脑》 1995年第6期31-32,共2页
这是一个我最近经常反复琢磨的问题。随着越来越多的人们联接Internet并且 访问World-Wide Web网点更加容易后,他们经常也会想,“下一步我将到哪儿呢?”下面是我的几个非常感兴趣的Web访问点。
关键词 虚拟图书馆 WebCrawler 主页 查询引擎 INTERNE 相似分类法 统一资源定位器 Windows WEB网 EINet
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An Approach to Unsupervised Character Classification Based on Similarity Measure in Fuzzy Model
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作者 卢达 钱忆平 +1 位作者 谢铭培 浦炜 《Journal of Southeast University(English Edition)》 EI CAS 2002年第4期370-376,共7页
This paper presents a fuzzy logic approach to efficiently perform unsupervised character classification for improvement in robustness, correctness and speed of a character recognition system. The characters are first ... This paper presents a fuzzy logic approach to efficiently perform unsupervised character classification for improvement in robustness, correctness and speed of a character recognition system. The characters are first split into eight typographical categories. The classification scheme uses pattern matching to classify the characters in each category into a set of fuzzy prototypes based on a nonlinear weighted similarity function. The fuzzy unsupervised character classification, which is natural in the repre... 展开更多
关键词 fuzzy model weighted fuzzy similarity measure unsupervised character classification matching algorithm classification hierarchy
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Vari-gram language model based on word clustering
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作者 袁里驰 《Journal of Central South University》 SCIE EI CAS 2012年第4期1057-1062,共6页
Category-based statistic language model is an important method to solve the problem of sparse data.But there are two bottlenecks:1) The problem of word clustering.It is hard to find a suitable clustering method with g... Category-based statistic language model is an important method to solve the problem of sparse data.But there are two bottlenecks:1) The problem of word clustering.It is hard to find a suitable clustering method with good performance and less computation.2) Class-based method always loses the prediction ability to adapt the text in different domains.In order to solve above problems,a definition of word similarity by utilizing mutual information was presented.Based on word similarity,the definition of word set similarity was given.Experiments show that word clustering algorithm based on similarity is better than conventional greedy clustering method in speed and performance,and the perplexity is reduced from 283 to 218.At the same time,an absolute weighted difference method was presented and was used to construct vari-gram language model which has good prediction ability.The perplexity of vari-gram model is reduced from 234.65 to 219.14 on Chinese corpora,and is reduced from 195.56 to 184.25 on English corpora compared with category-based model. 展开更多
关键词 word similarity word clustering statistical language model vari-gram language model
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Classification of hyperspectral remote sensing images using frequency spectrum similarity 被引量:10
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作者 WANG Ke GU XingFa +3 位作者 YU Tao MENG QingYan ZHAO LiMin FENG Li 《Science China(Technological Sciences)》 SCIE EI CAS 2013年第4期980-988,共9页
An algorithm of hyperspectral remote sensing images classification is proposed based on the frequency spectrum of spectral signature.The spectral signature of each pixel in the hyperspectral image is taken as a discre... An algorithm of hyperspectral remote sensing images classification is proposed based on the frequency spectrum of spectral signature.The spectral signature of each pixel in the hyperspectral image is taken as a discrete signal,and the frequency spectrum is obtained using discrete Fourier transform.The discrepancy of frequency spectrum between ground objects' spectral signatures is visible,thus the difference between frequency spectra of reference and target spectral signature is used to measure the spectral similarity.Canberra distance is introduced to increase the contribution from higher frequency components.Then,the number of harmonics involved in the proposed algorithm is determined after analyzing the frequency spectrum energy cumulative distribution function of ground object.In order to evaluate the performance of the proposed algorithm,two hyperspectral remote sensing images are adopted as experimental data.The proposed algorithm is compared with spectral angle mapper (SAM),spectral information divergence (SID) and Euclidean distance (ED) using the product accuracy,user accuracy,overall accuracy,average accuracy and Kappa coefficient.The results show that the proposed algorithm can be applied to hyperspectral image classification effectively. 展开更多
关键词 hyperspectral image spectral similarity frequency spectrum feature remote sensing CLASSIFICATION
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