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Cross-Project Software Defect Prediction Based on SMOTE and Deep Canonical Correlation Analysis
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作者 Xin Fan Shuqing Zhang +2 位作者 Kaisheng Wu Wei Zheng Yu Ge 《Computers, Materials & Continua》 SCIE EI 2024年第2期1687-1711,共25页
Cross-Project Defect Prediction(CPDP)is a method that utilizes historical data from other source projects to train predictive models for defect prediction in the target project.However,existing CPDP methods only consi... Cross-Project Defect Prediction(CPDP)is a method that utilizes historical data from other source projects to train predictive models for defect prediction in the target project.However,existing CPDP methods only consider linear correlations between features(indicators)of the source and target projects.These models are not capable of evaluating non-linear correlations between features when they exist,for example,when there are differences in data distributions between the source and target projects.As a result,the performance of such CPDP models is compromised.In this paper,this paper proposes a novel CPDP method based on Synthetic Minority Oversampling Technique(SMOTE)and Deep Canonical Correlation Analysis(DCCA),referred to as S-DCCA.Canonical Correlation Analysis(CCA)is employed to address the issue of non-linear correlations between features of the source and target projects.S-DCCA extends CCA by incorporating the MlpNet model for feature extraction from the dataset.The redundant features are then eliminated by maximizing the correlated feature subset using the CCA loss function.Finally,cross-project defect prediction is achieved through the application of the SMOTE data sampling technique.Area Under Curve(AUC)and F1 scores(F1)are used as evaluation metrics.This paper conducted experiments on 27 projects from four public datasets to validate the proposed method.The results demonstrate that,on average,our method outperforms all baseline approaches by at least 1.2%in AUC and 5.5%in F1 score.This indicates that the proposed method exhibits favorable performance characteristics. 展开更多
关键词 Cross-project defect prediction deep canonical correlation analysis feature similarity
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Canonical Correlation Analysis of Agronomic Characters of Brassica juncea in Western China
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作者 大次卓嘎 王建林 +1 位作者 次仁央金 王忠红 《Agricultural Science & Technology》 CAS 2011年第11期1600-1604,1666,共6页
[Objective] The study aimed at exploring the relationship among the agronomic characters of B. juncea in western China, in order to provide scientific basis for the breeding of B. juncea in western China. [Method] 39 ... [Objective] The study aimed at exploring the relationship among the agronomic characters of B. juncea in western China, in order to provide scientific basis for the breeding of B. juncea in western China. [Method] 39 B. juncea materials from western China were used for the canonical correlation analysis, and canonical correlations between each pair of the four ecological character (containing 18 variables) were verified, including yield characters (5 variables), caulis characters (6 variables), branch characters (3 variables) and pod characters (3 variables). [Result] Yield per plant of B. juncea in western China suffered a tremendous influence from effective pod number per plant while was not significantly affected by the total pod number per plant, seed number per pod and 1 000-seed weight; the most important character related with the yield character of B. juncea in western China was caulis character, followed by the branch character and pod character; yield characters, caulis characters, branch characters and pod characters of B. juncea in western China were closely correlated. [Conclusion] In order to improve the yield characters of B. juncea in western China, caulis characters should be focused on, followed by branch characters and pod characters; rapeseed varieties with high performance in total pod number per plant and effective pod number per plant should be chosen through the perspectives of effective branch number, plant height, pod number of main inflorescence, fruit stalk number of main inflorescence and other traits, while rapeseed varieties with high performance in seed number per pod and 1 000-seed weight should be chosen through the perspectives of beak length and other traits. 展开更多
关键词 Western China Brassica juncea Ecological character canonical correlation analysis Comparative study
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Feature Fusion Multi-View Hashing Based on Random Kernel Canonical Correlation Analysis 被引量:2
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作者 Junshan Tan Rong Duan +2 位作者 Jiaohua Qin Xuyu Xiang Yun Tan 《Computers, Materials & Continua》 SCIE EI 2020年第5期675-689,共15页
Hashing technology has the advantages of reducing data storage and improving the efficiency of the learning system,making it more and more widely used in image retrieval.Multi-view data describes image information mor... Hashing technology has the advantages of reducing data storage and improving the efficiency of the learning system,making it more and more widely used in image retrieval.Multi-view data describes image information more comprehensively than traditional methods using a single-view.How to use hashing to combine multi-view data for image retrieval is still a challenge.In this paper,a multi-view fusion hashing method based on RKCCA(Random Kernel Canonical Correlation Analysis)is proposed.In order to describe image content more accurately,we use deep learning dense convolutional network feature DenseNet to construct multi-view by combining GIST feature or BoW_SIFT(Bag-of-Words model+SIFT feature)feature.This algorithm uses RKCCA method to fuse multi-view features to construct association features and apply them to image retrieval.The algorithm generates binary hash code with minimal distortion error by designing quantization regularization terms.A large number of experiments on benchmark datasets show that this method is superior to other multi-view hashing methods. 展开更多
关键词 HASHING multi-view data random kernel canonical correlation analysis feature fusion deep learning
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Study on soil water characteristics of tobacco fields based on canonical correlation analysis 被引量:1
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作者 Xiao-hou SHAO Yu WANG +3 位作者 Li-dong BI You-bo YUAN Xian-kun SU Jian-guo MO 《Water Science and Engineering》 EI CAS 2009年第2期79-86,共8页
In order to identify the principal factors influencing soil water characteristics (SWC) and evaluate SWC effectively, the multivariate-statistical canonical correlation analysis (CCA) method was used to study and ... In order to identify the principal factors influencing soil water characteristics (SWC) and evaluate SWC effectively, the multivariate-statistical canonical correlation analysis (CCA) method was used to study and analyze the correlation between SWC and soil physical and chemical properties. Twenty-two soil samples were taken from 11 main tobacco-growing areas in Guizhou Province in China and the soil water characteristic curves (SWCC) and basic physical and chemical properties of the soil samples were determined. The results show that: (1) The soil bulk density, soil total porosity and soil capillary porosity have significant effects on SWC of tobacco fiels. Bulk density and total porosity are positively correlated with soil water retention characteristics (SWRC), and soil capillary porosity is positively correlated with soil water supply characteristics (SWSC). (2) Soil samples from different soil layers at the same soil sampling point show similarity or consistency in SWC. Inadequate soil water supply capability and imbalance between SWRC and SWSC are problems of tobacco soil. (3) The SWC of loamy clay are generally superior to those of silty clay loam. 展开更多
关键词 canonical correlation analysis tobacco soils soil water characteristics soil texture
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Novel DDoS Feature Representation Model Combining Deep Belief Network and Canonical Correlation Analysis 被引量:2
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作者 Chen Zhang Jieren Cheng +3 位作者 Xiangyan Tang Victor SSheng Zhe Dong Junqi Li 《Computers, Materials & Continua》 SCIE EI 2019年第8期657-675,共19页
Distributed denial of service(DDoS)attacks launch more and more frequently and are more destructive.Feature representation as an important part of DDoS defense technology directly affects the efficiency of defense.Mos... Distributed denial of service(DDoS)attacks launch more and more frequently and are more destructive.Feature representation as an important part of DDoS defense technology directly affects the efficiency of defense.Most DDoS feature extraction methods cannot fully utilize the information of the original data,resulting in the extracted features losing useful features.In this paper,a DDoS feature representation method based on deep belief network(DBN)is proposed.We quantify the original data by the size of the network flows,the distribution of IP addresses and ports,and the diversity of packet sizes of different protocols and train the DBN in an unsupervised manner by these quantified values.Two feedforward neural networks(FFNN)are initialized by the trained deep belief network,and one of the feedforward neural networks continues to be trained in a supervised manner.The canonical correlation analysis(CCA)method is used to fuse the features extracted by two feedforward neural networks per layer.Experiments show that compared with other methods,the proposed method can extract better features. 展开更多
关键词 Deep belief network DDoS feature representation canonical correlation analysis
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ASSESSMENT OF INFLUENCE IN CANONICAL CORRELATION ANALYSIS
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作者 岳荣先 鲁国斌 《Journal of Southeast University(English Edition)》 EI CAS 1993年第2期60-68,共9页
By expanding the perturbation of covariance matrix in the powers of er-ror term,the influence functions for five canonical measurements in CCA are devel-oped and three sample versions are given.For generalized correla... By expanding the perturbation of covariance matrix in the powers of er-ror term,the influence functions for five canonical measurements in CCA are devel-oped and three sample versions are given.For generalized correlation coefficient p_z,the influence function is a quadratic form of r.v.z,and its distribution is considered.A practical example iUustrates the utility of the proposed influence functions. 展开更多
关键词 canonical correlation analysis perturbation/influence FUNCTION influential OBSERVATION
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SPATIAL REGULARIZATION OF CANONICAL CORRELATION ANALYSIS FOR LOW-RESOLUTION FACE RECOGNITION
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作者 周旭东 陈晓红 钱强 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2013年第1期77-81,共5页
Canonical correlation analysis ( CCA ) based methods for low-resolution ( LR ) face recognition involve face images with different resolutions ( or multi-resolutions ), i.e.LR and high-resolution ( HR ) .For single-re... Canonical correlation analysis ( CCA ) based methods for low-resolution ( LR ) face recognition involve face images with different resolutions ( or multi-resolutions ), i.e.LR and high-resolution ( HR ) .For single-resolution face recognition , researchers have shown that utilizing spatial information is beneficial to improving the recognition accuracy , mainly because the pixels of each face are not independent but spatially correlated.However , for a multi-resolution scenario , there are no related works.Therefore , a method named spatial regularization of canonical correlation analysis ( SRCCA ) is developed for LR face recognition to improve the performance of CCA by the regularization utilizing spatial information of different resolution faces.Furthermore , the impact of LR and HR spatial regularization terms on LR face recognition is analyzed through experiments. 展开更多
关键词 face recognition canonical correlation analysis low-resolution spatial information
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Canonical correlation analysis to land-use structure and its driving forces——Taking Yulin Prefecture as an example
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作者 ZHANG MingInstitute of Geography, CAS, Beijing 100101 CHINA 《Journal of Geographical Sciences》 SCIE CSCD 1998年第2期73-79,共7页
In this paper, one of the most classical statistical methods, Canonical Correlation Analysis (CCA) is applied to identify quantitatively the driving forces of landuse structure in Yulin Prefecture. The main analysis i... In this paper, one of the most classical statistical methods, Canonical Correlation Analysis (CCA) is applied to identify quantitatively the driving forces of landuse structure in Yulin Prefecture. The main analysis is carried out through the software SPSS with the data on the level of towns and townships in 1992. The results indicate that landuse structure is determined by comprehensive action of different factors. Landuse structure with rural characteristics is mainly determined by geographical factors such as the elevation, temperature and precipitation, while the landuse structure with urban characteristics is mainly determined by demographic and socioeconomic conditions. At the same time, tests were carried out through the canonical correlation coefficient and redundancy analysis. 展开更多
关键词 canonical correlation analysis Redundancy analysis landuse and landcover change driving force
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ON USING NON-LINEAR CANONICAL CORRELATION ANALYSIS FOR VOICE CONVERSION BASED ON GAUSSIAN MIXTURE MODEL
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作者 Jian Zhihua Yang Zhen 《Journal of Electronics(China)》 2010年第1期1-7,共7页
Voice conversion algorithm aims to provide high level of similarity to the target voice with an acceptable level of quality.The main object of this paper was to build a nonlinear relationship between the parameters fo... Voice conversion algorithm aims to provide high level of similarity to the target voice with an acceptable level of quality.The main object of this paper was to build a nonlinear relationship between the parameters for the acoustical features of source and target speaker using Non-Linear Canonical Correlation Analysis(NLCCA) based on jointed Gaussian mixture model.Speaker indi-viduality transformation was achieved mainly by altering vocal tract characteristics represented by Line Spectral Frequencies(LSF).To obtain the transformed speech which sounded more like the target voices,prosody modification is involved through residual prediction.Both objective and subjective evaluations were conducted.The experimental results demonstrated that our proposed algorithm was effective and outperformed the conventional conversion method utilized by the Minimum Mean Square Error(MMSE) estimation. 展开更多
关键词 Speech processing Voice conversion Non-Linear canonical correlation analysis(NLcca) Gaussian Mixture Model(GMM)
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A NOVEL ALGORITHM FOR VOICE CONVERSION USING CANONICAL CORRELATION ANALYSIS
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作者 Jian Zhihua Yang Zhen 《Journal of Electronics(China)》 2008年第3期358-363,共6页
A novel algorithm for voice conversion is proposed in this paper. The mapping function of spectral vectors of the source and target speakers is calculated by the Canonical Correlation Analysis (CCA) estimation based o... A novel algorithm for voice conversion is proposed in this paper. The mapping function of spectral vectors of the source and target speakers is calculated by the Canonical Correlation Analysis (CCA) estimation based on Gaussian mixture models. Since the spectral envelope feature remains a majority of second order statistical information contained in speech after Linear Prediction Coding (LPC) analysis, the CCA method is more suitable for spectral conversion than Minimum Mean Square Error (MMSE) because CCA explicitly considers the variance of each component of the spectral vectors during conversion procedure. Both objective evaluations and subjective listening tests are conducted. The experimental results demonstrate that the proposed scheme can achieve better per- formance than the previous method which uses MMSE estimation criterion. 展开更多
关键词 Speech processing Voice conversion canonical correlation analysis cca
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Canonical Correlation Analysis and climate research
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作者 Gordon G. Liao 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1989年第3期351-358,共8页
Correlation analysis as used by meteorologists and oceanographers is a tool for the analysisof the spacial or temporal variability of physical fields. In his notes, Dr. Hasselmann pro-posed to combine correlation anal... Correlation analysis as used by meteorologists and oceanographers is a tool for the analysisof the spacial or temporal variability of physical fields. In his notes, Dr. Hasselmann pro-posed to combine correlation analysis and linear regression analysis in climate prediction re-search. The main idea is to decompose the physical field into its principal oscillation patterns. 展开更多
关键词 LRA canonical correlation analysis and climate research
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Multiple moving sources passive location based on multiset canonical correlation analysis
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作者 禹华钢 Huang Gaoming Gao Jun 《High Technology Letters》 EI CAS 2013年第2期197-202,共6页
To solve the problem of multiple moving sources passive location, a novel blind source separa- tion (BSS) algorithm based on the muhiset canonical correlation analysis (MCCA) is presented by exploiting the differe... To solve the problem of multiple moving sources passive location, a novel blind source separa- tion (BSS) algorithm based on the muhiset canonical correlation analysis (MCCA) is presented by exploiting the different temporal structure of uncorrelated source signals first, and then on the basis of this algorithm, a novel multiple moving sources passive location method is proposed using time difference of arrival (TDOA) and frequency difference of arrival (FDOA) measurements. The key technique of this location method is TDOA and FDOA joint estimation, which is based on BSS. By blindly separating mixed signals from multiple moving sources, the multiple sources location problem can be translated to each source location in turn, and the effect of interference and noise can also he removed. The simulation results illustrate that the performance of the MCCA algorithm is very good with relatively light computation burden, and the location algorithm is relatively simple and effective. 展开更多
关键词 multiset canonical correlation analysis (Mcca blind source separation (BSS) time difference of arrival (TDOA) frequency difference of arrival (FDOA) passive location mul-tiple sources
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基于PSD特征的FBCCA脑电信号识别方法 被引量:1
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作者 张学军 杨京儒 《科学技术与工程》 北大核心 2024年第4期1411-1417,共7页
当前基于稳态视觉诱发电位(steady-state visual evoked potential,SSVEP)的脑机接口(brain-computer interfaces,BCIs)使用的都是单一识别算法,针对不同时间长度的识别准确率较低。提出了一种基于滤波器组的典型相关分析(filter bank c... 当前基于稳态视觉诱发电位(steady-state visual evoked potential,SSVEP)的脑机接口(brain-computer interfaces,BCIs)使用的都是单一识别算法,针对不同时间长度的识别准确率较低。提出了一种基于滤波器组的典型相关分析(filter bank canonical correlation analysis,FBCCA)与功率谱密度(power spectral density,PSD)分析相结合的SSVEP识别算法,可以提高SSVEP识别的普适性与准确率。该方法使用FBCCA寻找高相似度的参考频率信号,再通过多组PSD分析来锁定最终的响应频率,完成频率识别。该方法无需经过训练就能得到较高的识别准确率。实验结果表明:在刺激时长为1 s时,该方法能达到86.61%的准确率,比PSD分析方法提升了5.44%,比典型相关性分析方法(canonical correlation analysis,CCA)提升了10.38%的准确率,比FBCCA提升了8.86%的准确率。 展开更多
关键词 脑机接口(BCI) 稳态视觉诱发电位(SSVEP) 滤波器组的典型相关分析(FBcca) 功率谱密度(PSD) 频率识别
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基于MLCCA的高速列车牵引系统故障诊断
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作者 程超 霍乃西 +2 位作者 许水清 蒲茜 陈宏田 《控制工程》 CSCD 北大核心 2024年第7期1163-1168,共6页
随着高速列车牵引系统的复杂性和智能性的提高,牵引系统的故障诊断越来越重要,故提出了一种基于多层典型相关分析(multi-layer canonical correlation analysis,MLCCA)的故障诊断方法。该方法对数据进行非线性预测,达到提高牵引系统的... 随着高速列车牵引系统的复杂性和智能性的提高,牵引系统的故障诊断越来越重要,故提出了一种基于多层典型相关分析(multi-layer canonical correlation analysis,MLCCA)的故障诊断方法。该方法对数据进行非线性预测,达到提高牵引系统的故障检测性能的目的,并引入最小绝对值收缩和选择算子(least absolute shrinkage and selection operator,LASSO)中的惩罚项来提高预测精度。根据高速列车传感器数据的性质,对数据进行分组分析,设置2组不同的统计量比较算法的检测效果。采集牵引系统传感器故障时的数据进行仿真实验,并将所提方法与常用方法进行对比,实验结果验证了所提方法的优越性。 展开更多
关键词 故障诊断 高速列车牵引系统 多层典型相关分析 LASSO
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基于CCA-ELM模型的国产LNG出厂价格中短期预测研究——以陕西省为例 被引量:1
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作者 潘凯 谢翔 +7 位作者 张曦 刘定智 张晗 张元涛 邓钰暄 贺美 李慧慧 孙仁金 《国际石油经济》 2024年第7期99-106,共8页
考虑供需基本面因素和非基本面因素,构建CCA-ELM模型用于国产LNG出厂价格的预测。供需基本面因素包括LNG的产量、销量、库存、气温以及原料气成本,非基本面影响因素包括原油、汽油、柴油、煤炭等替代能源价格与东北亚天然气现货价格。... 考虑供需基本面因素和非基本面因素,构建CCA-ELM模型用于国产LNG出厂价格的预测。供需基本面因素包括LNG的产量、销量、库存、气温以及原料气成本,非基本面影响因素包括原油、汽油、柴油、煤炭等替代能源价格与东北亚天然气现货价格。通过典型相关性分析,研究各个影响因素对价格的作用程度。以10个影响因素的周度数据为研究对象,以LNG出厂价格的历史序列与其影响因素构建CCA-ELM神经网络预测模型。10个影响因素整体与LNG出厂价格的相关性较强,中国LNG出厂价格受能源市场的影响程度较高,受供需基本面的影响程度较低。兼顾LNG出厂价格历史数据与影响因素的CCA-ELM模型有效改进了时间序列神经网络的预测方法,提高了预测精度。 展开更多
关键词 LNG出厂价格 影响因素 ELM神经网络 典型相关分析
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A Novel CCA-NMF Whitening Method for Practical Machine Learning Based Underwater Direction of Arrival Estimation
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作者 Yun Wu Xinting Li Zhimin Cao 《Journal of Beijing Institute of Technology》 EI CAS 2024年第2期163-174,共12页
Underwater direction of arrival(DOA)estimation has always been a very challenging theoretical and practical problem.Due to the serious non-stationary,non-linear,and non-Gaussian characteristics,machine learning based ... Underwater direction of arrival(DOA)estimation has always been a very challenging theoretical and practical problem.Due to the serious non-stationary,non-linear,and non-Gaussian characteristics,machine learning based DOA estimation methods trained on simulated Gaussian noised array data cannot be directly applied to actual underwater DOA estimation tasks.In order to deal with this problem,environmental data with no target echoes can be employed to analyze the non-Gaussian components.Then,the obtained information about non-Gaussian components can be used to whiten the array data.Based on these considerations,a novel practical sonar array whitening method was proposed.Specifically,based on a weak assumption that the non-Gaussian components in adjacent patches with and without target echoes are almost the same,canonical cor-relation analysis(CCA)and non-negative matrix factorization(NMF)techniques are employed for whitening the array data.With the whitened array data,machine learning based DOA estimation models trained on simulated Gaussian noised datasets can be used to perform underwater DOA estimation tasks.Experimental results illustrated that,using actual underwater datasets for testing with known machine learning based DOA estimation models,accurate and robust DOA estimation performance can be achieved by using the proposed whitening method in different underwater con-ditions. 展开更多
关键词 direction of arrival(DOA) sonar array data underwater disturbance machine learn-ing canonical correlation analysis(cca) non-negative matrix factorization(NMF)
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2008年苏州阳澄湖浮游藻类群落结构与环境因子的CCA分析 被引量:16
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作者 陈立婧 吴淑贤 +3 位作者 彭自然 胡忠军 王武 薛俊增 《生物学杂志》 CAS CSCD 2012年第6期65-69,共5页
2008年1月—12月对江苏阳澄湖的浮游藻类进行了调查,分析了藻类的群落结构、物种多样性以及其与阳澄湖生态环境的相互关系。共发现藻类8门124属324种(包括变种),全年优势种为铜绿微囊藻(Microcystis aerugini-sa)、小席藻(Phorimidium t... 2008年1月—12月对江苏阳澄湖的浮游藻类进行了调查,分析了藻类的群落结构、物种多样性以及其与阳澄湖生态环境的相互关系。共发现藻类8门124属324种(包括变种),全年优势种为铜绿微囊藻(Microcystis aerugini-sa)、小席藻(Phorimidium tenus)、不定微囊藻(M.incerta)、密集微囊藻(M.densa)等。藻类的年平均丰度为3462.93×104cell/L,年平均生物量为8.09 mg/L。利用生物学指标对湖泊进行营养状况评价,阳澄湖属于α-中污染富营养型湖泊。CCA分析表明阳澄湖的蓝藻主要分布在夏、秋季,绿藻在夏季受到微囊藻的抑制,硅藻主要分布在春、冬季,金藻和黄藻主要分布在冬季;温度是阳澄湖藻类的首要影响因子,总氮与总磷的影响作用由入湖河道向东湖逐步减小。 展开更多
关键词 阳澄湖 藻类 环境因子 典范相关分析(cca)
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基于加权局部判别CCA的多视角步态识别方法 被引量:11
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作者 王献锋 黄文准 张善文 《计算机工程与应用》 CSCD 北大核心 2018年第21期90-94,共5页
为了解决步态特征提取难题和克服单一视觉的步态进行身份识别方法的局限性,提出一种加权局部判别典型相关分析(WLDCCA)算法。在此基础上,提出一种基于WLDCCA的多视角步态识别方法。该方法通过在WLDCCA中引入样本的类信息和局部信息,将... 为了解决步态特征提取难题和克服单一视觉的步态进行身份识别方法的局限性,提出一种加权局部判别典型相关分析(WLDCCA)算法。在此基础上,提出一种基于WLDCCA的多视角步态识别方法。该方法通过在WLDCCA中引入样本的类信息和局部信息,将不同视觉的步态特征有机地融合起来,提取的融合特征能够最小化同类样本之间的距离,同时最大化异类样本之间的距离,提高了步态识别的识别率和鲁棒性。在CASIA步态数据库上的实验结果验证了该算法的有效性和可行性。 展开更多
关键词 多视角步态识别 典型相关分析(cca) 局部判别cca(LDcca) 加权LDcca(WLDcca)
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典型相关分析(CCA)对我国冬季气温的短期气候预测试验 被引量:16
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作者 毛恒青 李小泉 《应用气象学报》 CSCD 北大核心 1997年第4期385-392,共8页
利用典型相关分析(CCA)方法建立统计气候预测模型,对我国冬季气温进行了预测试验,采用历史资料独立样本检验的方法,对预报技巧给出合理的评定.结果表明,使用CCA方法对我国冬季气温进行短期气候预测,有一定的预报技巧,对... 利用典型相关分析(CCA)方法建立统计气候预测模型,对我国冬季气温进行了预测试验,采用历史资料独立样本检验的方法,对预报技巧给出合理的评定.结果表明,使用CCA方法对我国冬季气温进行短期气候预测,有一定的预报技巧,对于特定地区和特定时期优选的因子场组合,可以取得较为满意的预报效果.大部分地区的季平均预报时效在2个季以内时,最佳预报相关系数在0.5以上.季平均的预报水平明显高于月平均的预报.海温场是所有因子场中最好的预报因子.不仅单独海温场的预报效果较好,而且与其它因子场组合后的预报水平还可以得到进一步提高. 展开更多
关键词 相关分析 预报试验 相关系数 气温 短期气候预测
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基于CCA的坡面尺度生物结皮空间分布 被引量:10
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作者 张朋 卜崇峰 +3 位作者 杨永胜 叶菁 张晓萍 石志华 《生态学报》 CAS CSCD 北大核心 2015年第16期5412-5420,共9页
生物结皮是干旱半干旱地区普遍存在的活地被物,在该区生态系统中具有重要的生态功能。探讨生物结皮的空间分布规律是科学管理该资源的理论基础。选择黄土高原水蚀风蚀交错区六道沟小流域内的典型坡面,通过全面调查并应用GS+和CANOCO统... 生物结皮是干旱半干旱地区普遍存在的活地被物,在该区生态系统中具有重要的生态功能。探讨生物结皮的空间分布规律是科学管理该资源的理论基础。选择黄土高原水蚀风蚀交错区六道沟小流域内的典型坡面,通过全面调查并应用GS+和CANOCO统计软件进行分析,探讨了坡面尺度上生物结皮的空间分布特征及其影响因子。结果表明:(1)生物结皮的分布具有明显的空间分异性。沙土区生物结皮以大面积连续分布为主,平均结皮盖度在30%以上;在黄土区则以零星分布为主,结皮盖度大都在20%以下,主要分布在坡的边缘和末端。而生物结皮厚度和抗剪强度的空间变异不大,说明其主要与生物结皮的发育年限有关。(2)典范对应分析(CCA)表明:生物结皮的空间分布与土壤、植被、地表湿度、坡度坡向等有密切关系。其中,土壤类型和生物结皮的空间分布关系最大,可以解释生物结皮空间变异的20%。其次是植被群落类型和地形湿度指数,沙蒿(Artemisia desertorum Spreng.Syst.Veg.)地和小叶杨(Populus simonii Carr.)林地是其最理想的生长环境;其他如坡度、坡向、太阳辐射等也都对生物结皮的分布有一定的影响。总体上,生物结皮具有明显的地形、土壤和植被群落的选择性,偏向于生长在较湿润的沙生植被群落当中。 展开更多
关键词 生物结皮(BSCs) 典范对应分析(cca) 水蚀风蚀交错区 坡面尺度 空间分布
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