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Fast Tensor Principal Component Analysis via Proximal Alternating Direction Method with Vectorized Technique
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作者 Haiyan Fan Gangyao Kuang Linbo Qiao 《Applied Mathematics》 2017年第1期77-86,共10页
This paper studies the problem of tensor principal component analysis (PCA). Usually the tensor PCA is viewed as a low-rank matrix completion problem via matrix factorization technique, and nuclear norm is used as a c... This paper studies the problem of tensor principal component analysis (PCA). Usually the tensor PCA is viewed as a low-rank matrix completion problem via matrix factorization technique, and nuclear norm is used as a convex approximation of the rank operator under mild condition. However, most nuclear norm minimization approaches are based on SVD operations. Given a matrix , the time complexity of SVD operation is O(mn2), which brings prohibitive computational complexity in large-scale problems. In this paper, an efficient and scalable algorithm for tensor principal component analysis is proposed which is called Linearized Alternating Direction Method with Vectorized technique for Tensor Principal Component Analysis (LADMVTPCA). Different from traditional matrix factorization methods, LADMVTPCA utilizes the vectorized technique to formulate the tensor as an outer product of vectors, which greatly improves the computational efficacy compared to matrix factorization method. In the experiment part, synthetic tensor data with different orders are used to empirically evaluate the proposed algorithm LADMVTPCA. Results have shown that LADMVTPCA outperforms matrix factorization based method. 展开更多
关键词 TENSOR principal component ANALYSIS PROXIMAL ALTERNATING Direction method Vectorized TECHNIQUE
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Kernel Generalization of Multi-Rate Probabilistic Principal Component Analysis for Fault Detection in Nonlinear Process 被引量:3
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作者 Donglei Zheng Le Zhou Zhihuan Song 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2021年第8期1465-1476,共12页
In practical process industries,a variety of online and offline sensors and measuring instruments have been used for process control and monitoring purposes,which indicates that the measurements coming from different ... In practical process industries,a variety of online and offline sensors and measuring instruments have been used for process control and monitoring purposes,which indicates that the measurements coming from different sources are collected at different sampling rates.To build a complete process monitoring strategy,all these multi-rate measurements should be considered for data-based modeling and monitoring.In this paper,a novel kernel multi-rate probabilistic principal component analysis(K-MPPCA)model is proposed to extract the nonlinear correlations among different sampling rates.In the proposed model,the model parameters are calibrated using the kernel trick and the expectation-maximum(EM)algorithm.Also,the corresponding fault detection methods based on the nonlinear features are developed.Finally,a simulated nonlinear case and an actual pre-decarburization unit in the ammonia synthesis process are tested to demonstrate the efficiency of the proposed method. 展开更多
关键词 Fault detection kernel method multi-rate process probability principal component analysis(PPCA)
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FUZZY PRINCIPAL COMPONENT ANALYSIS AND ITS KERNEL-BASED MODEL 被引量:4
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作者 Wu Xiaohong Zhou Jianjiang 《Journal of Electronics(China)》 2007年第6期772-775,共4页
Principal Component Analysis(PCA)is one of the most important feature extraction methods,and Kernel Principal Component Analysis(KPCA)is a nonlinear extension of PCA based on kernel methods.In real world,each input da... Principal Component Analysis(PCA)is one of the most important feature extraction methods,and Kernel Principal Component Analysis(KPCA)is a nonlinear extension of PCA based on kernel methods.In real world,each input data may not be fully assigned to one class and it may partially belong to other classes.Based on the theory of fuzzy sets,this paper presents Fuzzy Principal Component Analysis(FPCA)and its nonlinear extension model,i.e.,Kernel-based Fuzzy Principal Component Analysis(KFPCA).The experimental results indicate that the proposed algorithms have good performances. 展开更多
关键词 principal component Analysis (PCA) Kernel methods Fuzzy PCA (FPCA) Kernel PCA (KPCA)
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Higher-order principal component pursuit via tensor approximation and convex optimization 被引量:1
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作者 Sijia Cai Ping Wang +1 位作者 Linhao Li Chuhan Zhang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2014年第3期523-530,共8页
Recovering the low-rank structure of data matrix from sparse errors arises in the principal component pursuit (PCP). This paper exploits the higher-order generalization of matrix recovery, named higher-order princip... Recovering the low-rank structure of data matrix from sparse errors arises in the principal component pursuit (PCP). This paper exploits the higher-order generalization of matrix recovery, named higher-order principal component pursuit (HOPCP), since it is critical in multi-way data analysis. Unlike the convexification (nuclear norm) for matrix rank function, the tensorial nuclear norm is stil an open problem. While existing preliminary works on the tensor completion field provide a viable way to indicate the low complexity estimate of tensor, therefore, the paper focuses on the low multi-linear rank tensor and adopt its convex relaxation to formulate the convex optimization model of HOPCP. The paper further propose two algorithms for HOPCP based on alternative minimization scheme: the augmented Lagrangian alternating direction method (ALADM) and its truncated higher-order singular value decomposition (ALADM-THOSVD) version. The former can obtain a high accuracy solution while the latter is more efficient to handle the computationally intractable problems. Experimental results on both synthetic data and real magnetic resonance imaging data show the applicability of our algorithms in high-dimensional tensor data processing. 展开更多
关键词 tensor recovery principal component pursuit alternating direction method tensor approximation.
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Decentralized Fault Diagnosis of Large-scale Processes Using Multiblock Kernel Principal Component Analysis 被引量:23
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作者 ZHANG Ying-Wei ZHOU Hong QIN S. Joe 《自动化学报》 EI CSCD 北大核心 2010年第4期593-597,共5页
关键词 分散系统 MBKPCA SPF PCA
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Combining Principal Component Regression and Artificial Neural Network to Predict Chlorophyll-a Concentration of Yuqiao Reservoir’s Outflow 被引量:1
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作者 张旋 王启山 +1 位作者 于淼 吴京 《Transactions of Tianjin University》 EI CAS 2010年第6期467-472,共6页
In order to investigate the eutrophication degree of Yuqiao Reservoir, a hybrid method, combining principal component regression (PCR) and artificial neural network (ANN), was adopted to predict chlorophyll-a concentr... In order to investigate the eutrophication degree of Yuqiao Reservoir, a hybrid method, combining principal component regression (PCR) and artificial neural network (ANN), was adopted to predict chlorophyll-a concentration of Yuqiao Reservoir’s outflow. The data were obtained from two sampling sites, site 1 in the reservoir, and site 2 near the dam. Seven water variables, namely chlorophyll-a concentration of site 2 at time t and that of both sites 10 days before t, total phosphorus(TP), total nitrogen(TN),... 展开更多
关键词 principal component regression artificial neural network hybrid method CHLOROPHYLL-A eutrophica-tion
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Robust Principal Component Analysis via Truncated Nuclear Norm Minimization
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作者 张艳 郭继昌 +1 位作者 赵洁 王博 《Journal of Shanghai Jiaotong university(Science)》 EI 2016年第5期576-583,共8页
Robust principal component analysis(PCA) is widely used in many applications, such as image processing, data mining and bioinformatics. The existing methods for solving the robust PCA are mostly based on nuclear norm ... Robust principal component analysis(PCA) is widely used in many applications, such as image processing, data mining and bioinformatics. The existing methods for solving the robust PCA are mostly based on nuclear norm minimization. Those methods simultaneously minimize all the singular values, and thus the rank cannot be well approximated in practice. We extend the idea of truncated nuclear norm regularization(TNNR) to the robust PCA and consider truncated nuclear norm minimization(TNNM) instead of nuclear norm minimization(NNM). This method only minimizes the smallest N-r singular values to preserve the low-rank components, where N is the number of singular values and r is the matrix rank. Moreover, we propose an effective way to determine r via the shrinkage operator. Then we develop an effective iterative algorithm based on the alternating direction method to solve this optimization problem. Experimental results demonstrate the efficiency and accuracy of the TNNM method. Moreover, this method is much more robust in terms of the rank of the reconstructed matrix and the sparsity of the error. 展开更多
关键词 truncated nuclear norm minimization(TNNM) robust principal component analysis(PCA) lowrank alternating direction method
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Principal Component-Discrimination Model and Its Application
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作者 韩天锡 魏雪丽 +1 位作者 蒋淳 张玉琍 《Transactions of Tianjin University》 EI CAS 2004年第4期315-318,共4页
Having researched for many years, seismologists in China presented about 80 earthquake prediction factors which reflected omen information of earthquake. How to concentrate the information that the 80 earthquake predi... Having researched for many years, seismologists in China presented about 80 earthquake prediction factors which reflected omen information of earthquake. How to concentrate the information that the 80 earthquake prediction factors have and how to choose the main factors to predict earthquakes precisely have become one of the topics in seismology. The model of principal component-discrimination consists of principal component analysis, correlation analysis, weighted method of principal factor coefficients and Mahalanobis distance discrimination analysis. This model combines the method of maximization earthquake prediction factor information with the weighted method of principal factor coefficients and correlation analysis to choose earthquake prediction variables, applying Mahalanobis distance discrimination to establishing earthquake prediction discrimination model. This model was applied to analyzing the earthquake data of Northern China area and obtained good prediction results. 展开更多
关键词 principal component analysis discrimination analysis correlation analysis weighted method of principal factor coefficients
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Principal component analysis and cluster analysis based orbit optimization for earth observation satellites
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作者 卫晓娜 DONG Yun-feng +3 位作者 LIU Feng-rui TIAN Lu HAO Zhao SHI Heng 《Journal of Chongqing University》 CAS 2016年第3期83-94,共12页
This paper proposes a design optimization method for the multi-objective orbit design of earth observation satellites, for which the optimality of orbit performance indices with different units, such as: total coverag... This paper proposes a design optimization method for the multi-objective orbit design of earth observation satellites, for which the optimality of orbit performance indices with different units, such as: total coverage time, the frequency of coverage, average time per coverage and maximum coverage gap, etc. is required simultaneously. By introducing index normalization method to convert performance indices into dimensionless variables within the range of [0, 1], a design optimization method based on the principal component analysis and cluster analysis is proposed, which consists of index normalization method, principal component analysis, multiple-level cluster analysis and weighted evaluation method. The results of orbit optimization for earth observation satellites show that the optimal orbit can be obtained by using the proposed method. The principal component analysis can reduce the total number of indices with a non-independent relationship to save computing time. Similarly, the multiple-level cluster analysis with parallel computing could save computing time. 展开更多
关键词 satellite orbit multi-objective optimization index normalization method principal component analysis cluster analysis
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Bankruptcy Prediction in the Polish Banking Industry Using Principal Component Analysis and BP Neural Network
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作者 Shiqing Li Qiancheng Tan 《Journal of Applied Mathematics and Physics》 2025年第5期1629-1643,共15页
With the rapid growth of the international banking industry,bank failures can lead to severe economic losses and social impacts.Although existing measures to address such failures are well-developed,timely prediction ... With the rapid growth of the international banking industry,bank failures can lead to severe economic losses and social impacts.Although existing measures to address such failures are well-developed,timely prediction can significantly mitigate these effects.This study analyzes key indicators influencing bank fail-ure through data analysis and correlation analysis,then develops a neural net-work-based risk prediction model to estimate failure probabilities.First,we ex-tracted 64 indicators from the dataset,identified the most relevant indicators using the entropy weight method,and established a bank efficiency evaluation formula to determine the failure threshold.Next,we applied principal compo-nent analysis(PCA)to reduce dimensionality and derive a comprehensive scoring formula.Based on these findings,we constructed a machine learning model in MATLAB to predict bank failures.Finally,the model was used to predict the failure probabilities of all banks and identify 20 representative existing and failed banks.The developed models effectively predict bank fail-ure risks and demonstrate strong applicability across different scenarios. 展开更多
关键词 BP Neural Network Entropy Weight method principal component Analysis
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Principal components of nuclear mass models
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作者 Xin-Hui Wu Pengwei Zhao 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2024年第7期65-71,共7页
Principal component analysis(PCA)is employed to extract the principal components(PCs)present in nuclear mass models for the first time.The effects from different nuclear mass models are reintegrated and reorganized in... Principal component analysis(PCA)is employed to extract the principal components(PCs)present in nuclear mass models for the first time.The effects from different nuclear mass models are reintegrated and reorganized in the extracted PCs.These PCs are recombined to build new mass models,which achieve better accuracy than the original theoretical mass models.This comparison indicates that using the PCA approach,the effects contained in different mass models can be collaborated to improve nuclear mass predictions. 展开更多
关键词 nuclear mass principal component analysis nuclear models statistical methods
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东营凹陷八面河地区古近系沙四段湖相白云岩测井识别及应用 被引量:1
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作者 胡心玲 荣焕青 +2 位作者 杨伟 张再昌 漆智先 《岩性油气藏》 CAS 北大核心 2025年第1期13-23,共11页
湖相白云岩储层岩石组分复杂、结构多样,利用测井资料对白云岩岩性进行识别具有重要意义。为了解决传统测井方法工作量大和识别精度低等问题,提出利用蛛网图-交会图-主成分分析法融合的方法,构建岩性敏感因子交会图,开展湖相白云岩岩性... 湖相白云岩储层岩石组分复杂、结构多样,利用测井资料对白云岩岩性进行识别具有重要意义。为了解决传统测井方法工作量大和识别精度低等问题,提出利用蛛网图-交会图-主成分分析法融合的方法,构建岩性敏感因子交会图,开展湖相白云岩岩性综合识别。研究结果表明:①东营凹陷八面河地区古近系沙四段主要由颗粒云岩、微晶云岩、泥晶云岩、砂岩和页岩等组成,其中,颗粒云岩、微晶云岩和页岩为主要岩石类型。②优选6类特征参数分析不同岩石类型蛛网图和交会图的差异,其中,GR和AC可有效区分颗粒云岩,SP对砂岩具有较好的识别效果,在蛛网图与交会图的识别成果基础上,应用主成分分析法对测井参数进行标准化处理,构建出累计方差贡献率为90.75%的主成分F1和F2,建立岩性判别模型,综合识别岩性。③通过产能与取心井验证,岩性识别准确度高达85.4%,明确研究区颗粒云岩在西部以SW—NE走向呈条带状分布,向南部和北部过渡为微晶云岩和泥晶云岩,东部则以不规则分布的砂岩为主。 展开更多
关键词 湖相白云岩 岩性测井识别 蛛网图 主成分分析法 沙四段 古近系 八面河地区 东营凹陷
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基于多复合测井参数的复杂岩性核主元识别方法——以开鲁盆地陆西凹陷九佛堂组储层为例 被引量:1
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作者 裴家学 郭晗 +5 位作者 周立国 张甲明 田涯 李皓 李雪英 隋强 《大庆石油地质与开发》 北大核心 2025年第2期136-146,共11页
开鲁盆地陆西凹陷九佛堂组储层复杂岩性与测井曲线之间存在非线性响应关系,致使常规岩性识别方法存在多解性和不确定性。为此引入4个与储层岩性相关的复合测井参数,增强测井曲线描述复杂岩性非线性响应特征能力;结合高斯核函数和多项式... 开鲁盆地陆西凹陷九佛堂组储层复杂岩性与测井曲线之间存在非线性响应关系,致使常规岩性识别方法存在多解性和不确定性。为此引入4个与储层岩性相关的复合测井参数,增强测井曲线描述复杂岩性非线性响应特征能力;结合高斯核函数和多项式核函数各自的优良特性,构建组合核函数,改善核主元分析方法的全局识别能力;采用K-折交叉验证法确定合理的核半径参数,从而建立一套基于多复合测井参数表征的复杂岩性核主元识别方法。实际岩性数据测试分析结果表明,引入多复合测井参数后,复杂岩性数据在核主元空间具有显著的线性可分性,岩性相对位置集中、固定且区带划分标准明确,表明该岩性划分方法具有良好的稳定性,后验识别符合率92.7%以上,证明该方法在复杂岩性识别中的有效性。研究成果为开鲁盆地复杂岩性区的岩性精确识别提供了一种新的技术思路。 展开更多
关键词 核主元分析 岩性识别 复合测井参数 组合核函数 K-折交叉验证法
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Synthetic Evaluation of Steady-state Power Quality Based on Combination Weighting and Principal Component Projection Method 被引量:20
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作者 Jidong Wang Wenjie Pang +2 位作者 Lipeng Wang Xipin Pang Ryuichi Yokoyama 《CSEE Journal of Power and Energy Systems》 SCIE 2017年第2期160-166,共7页
With integration of renewable energy and use of non-linear loads in power systems,the power quality problem is increasingly attracting attention of researchers.In China,standards for individual power quality indexes a... With integration of renewable energy and use of non-linear loads in power systems,the power quality problem is increasingly attracting attention of researchers.In China,standards for individual power quality indexes are set.However,when evaluating power quality in practice,individual indexes cannot directly reflect a comprehensive level of power quality.In this paper,a comprehensive analysis of various indexes is conducted to obtain a unified parameter for describing the characteristics of power quality from an overall perspective.First,weight values of power quality indexes are calculated by combining the subjective and objective weight.Then,based on the principal components of the projection method,projection values of boundary data and data to be evaluated are obtained.Finally,using these projection values,a grade range for power quality data is located.A practical case study is presented to show the validity of the proposed method for evaluating power quality. 展开更多
关键词 Combination weighting entropy weight method G1 method power quality principal component projection
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综合物探信息融合技术在土石坝渗漏隐患探测中的应用
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作者 徐力群 何英铭 +3 位作者 李东泽 张国琛 马泽锴 沈振中 《水利水电科技进展》 北大核心 2025年第3期86-92,共7页
为解决单一物探技术无法精准定位土石坝局部渗漏问题,结合面波法和高密度电法探测技术,将不同源原始探测数据转化为电阻率,提出了采用主成分分析法的综合物探信息融合技术,开展了预设3处渗漏隐患通道的均质土石坝物理模型试验,对比分析... 为解决单一物探技术无法精准定位土石坝局部渗漏问题,结合面波法和高密度电法探测技术,将不同源原始探测数据转化为电阻率,提出了采用主成分分析法的综合物探信息融合技术,开展了预设3处渗漏隐患通道的均质土石坝物理模型试验,对比分析两种单一物探技术与综合物探信息融合技术的渗漏通道定位区域,论证了综合物探技术的渗漏隐患定位的精准性,并给出了渗漏隐患区域的判别标准。将综合物探信息融合技术应用于某存在渗漏问题的土石坝工程,结果表明该技术具有无损探测、高效便捷、结果明显等优点,可实现渗漏隐患位置的精准定位。 展开更多
关键词 土石坝 渗漏探测 综合物探技术 信息融合 电阻率 主成分分析法
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浙江12种桑树叶片营养品质的综合评价
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作者 刘岩 林天宝 +3 位作者 魏佳 刘培刚 朱燕 吕志强 《浙江农业科学》 2025年第9期2253-2259,共7页
桑叶富含丰富营养物质和多种天然活性成分,已被用于养蚕、食品、制药等领域,具有广阔的应用前景。为分析评价桑叶营养品质,本研究对浙江12种桑树品种的叶片进行营养成分检测,结果表明:不同品种间各营养成分含量呈现一定差异,不同指标间... 桑叶富含丰富营养物质和多种天然活性成分,已被用于养蚕、食品、制药等领域,具有广阔的应用前景。为分析评价桑叶营养品质,本研究对浙江12种桑树品种的叶片进行营养成分检测,结果表明:不同品种间各营养成分含量呈现一定差异,不同指标间的变异系数也不同。经聚类分析将桑树叶片,分为富含多糖、脂肪类,富含生物碱类和富含氨基酸类。结合主成分分析、相关性分析和熵权法综合分析,确立桑叶营养品质中粗蛋白含量、粗纤维含量和总多糖含量这3个核心评价指标的权重系数分别为58.26%、29.68%和12.06%,经灰色关联度加权法分析的综合评价表明,综合品质排在前2位的为农桑8号和农桑14号。综上,本研究建立了桑叶营养品质综合评价方法,为今后桑树种质资源评价、新品种选育和利用提供指导。 展开更多
关键词 聚类分析 主成分分析 熵权法 灰色关联度 桑叶
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16个澳洲坚果在贵州南盘江流域的果实性状研究
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作者 张燕 何凤平 +4 位作者 郭广正 康专苗 王代谷 朱文华 李向勇 《贵州农业科学》 2025年第9期97-106,共10页
【目的】探明贵州南盘江流域种植的澳洲坚果果实品质,为当地澳洲坚果产业品种结构调整及推广提供参考依据。【方法】以贵州南盘江流域种植的O.C、H2、HAES695等16个澳洲坚果品种为材料,采用单因素方差分析、相关性分析和主成分分析等方... 【目的】探明贵州南盘江流域种植的澳洲坚果果实品质,为当地澳洲坚果产业品种结构调整及推广提供参考依据。【方法】以贵州南盘江流域种植的O.C、H2、HAES695等16个澳洲坚果品种为材料,采用单因素方差分析、相关性分析和主成分分析等方法分析果实性状,并进行基于隶属函数值法综合评价。【结果】南盘江流域16个澳洲坚果品种的果实性状存在差异,其中,C11果实鲜重最大,为27.43 g;南亚2号出籽率最高,为56.29%;C11壳果鲜重最大,为12.55 g;南亚2号壳果干重最大,为11.03 g;A4果仁干重最大,为3.60 g;南亚116号出仁率和得仁率均最高,分别为44.04%和18.51%。14个果实性状中,有5个性状变异系数低于10.00%,产量的变异系数最大(36.51%),壳果鲜重(15.26%)、壳果干重(15.22%)、果仁干重(15.04%)其次,各品种的果实性状指标间存在较强相关性,其中,影响产量的主要性状果实鲜重与除出籽率、出仁率和得仁率外的其他性状呈显著正相关;壳果干重与壳果横径、壳果纵径和果壳厚度呈极显著正相关,与果仁干重呈显著正相关;果仁干重与出仁率和得仁率呈显著正相关,因此,澳洲坚果品种果实性状评价和筛选应综合考虑各项性状指标。综合评价得分前5的澳洲坚果品种为O.C、HAES344、A4、C11、南亚3号,该5个品种在当地推广发展潜力较大。【结论】贵州南盘江流域16个澳洲坚果品种的果实性状存在一定差异,根据分析结果和实际生产情况,O.C的综合表现较好,可作为优良品种加以推广利用。 展开更多
关键词 澳洲坚果 果实 表型性状 主成分分析 隶属函数值法 南盘江流域
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基于主成分分析法与系统动力学的水资源承载力评价--以庆阳市为例
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作者 汪倩 袁波 +2 位作者 吴剑 刘文士 吴雁 《长江科学院院报》 北大核心 2025年第6期51-59,共9页
黄河流域资源型城市水资源承载力评价相关研究缺失,亟待填补以支撑黄河流域的生态保护与高质量发展战略。以油气资源城市庆阳市为例,其油气开发面临水资源短缺问题。结合庆阳市实际,融合动静评价法构建油气开发区水资源承载力评估体系,... 黄河流域资源型城市水资源承载力评价相关研究缺失,亟待填补以支撑黄河流域的生态保护与高质量发展战略。以油气资源城市庆阳市为例,其油气开发面临水资源短缺问题。结合庆阳市实际,融合动静评价法构建油气开发区水资源承载力评估体系,在静态评估中通过主成分分析法追溯历史变化并分析关键影响因素,动态评估则是采用系统动力学提出了4种优化方案,并对庆阳市2022—2035年水资源承载力趋势进行了预测。结果表明:2012—2022年,由于社会经济发展、水资源利用和生态建设等多方面因素的共同影响,庆阳市水资源承载力总体呈逐年下降趋势,年均下降幅度为18.78%;考虑节水、治污、经济调节等方面形成综合发展方案,认为可通过采取供需双向调整策略缓解水资源压力。研究成果可为庆阳市水资源调控提供参考。 展开更多
关键词 水资源承载力 评估体系 动静评价法 主成分分析 系统动力学 水资源调控 庆阳市
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石梁河许昌段水体富营养化特征研究
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作者 侯刚 吕慧瑶 +2 位作者 侯艳锋 刘雪锋 徐永新 《绿色科技》 2025年第16期72-76,共5页
石梁河许昌段是农业灌溉和城市供水的重要水源,其水质状况直接影响农业生产和居民生活。为评估该河段富营养化水平,本研究于2024年3月采集水样,测定了总氮(TN)、总磷(TP)、高锰酸盐指数(COD_(Mn))、化学需氧量(COD)和透明度(SD)五项指... 石梁河许昌段是农业灌溉和城市供水的重要水源,其水质状况直接影响农业生产和居民生活。为评估该河段富营养化水平,本研究于2024年3月采集水样,测定了总氮(TN)、总磷(TP)、高锰酸盐指数(COD_(Mn))、化学需氧量(COD)和透明度(SD)五项指标。运用主成分分析、单因子分析和综合营养状态指数法进行评价。结果表明:TN是主要污染因子;主成分分析显示水质特征可由2个主成分表征,其中9个采样点达Ⅱ类水标准,10个达Ⅲ类标准;综合营养指数(TLI(Σ))范围为48.34~68.60(均值56.60),水质整体呈轻度富营养化状态,部分区域为中营养或中度富营养。本研究为石梁河许昌段的水资源保护与治理提供了科学依据。 展开更多
关键词 富营养化评价 主成分分析法 综合营养状态指数 石梁河
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咖啡种子表型性状的多样性分析和综合评价
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作者 武瑞瑞 李亚男 +3 位作者 张晓芳 吕玉兰 杨旸 李贵平 《热带农业科学》 2025年第8期23-29,共7页
分析不同产地不同咖啡品种种子性状变异及开展种子性状综合评价,以期筛选出优良种质。对采自保山潞江坝、临沧幸福镇、普洱、德宏瑞丽和芒市等地33个咖啡种子进行考种,测定种子质量、种子长、种子宽、紧致度、长宽比、形数、种子含水量... 分析不同产地不同咖啡品种种子性状变异及开展种子性状综合评价,以期筛选出优良种质。对采自保山潞江坝、临沧幸福镇、普洱、德宏瑞丽和芒市等地33个咖啡种子进行考种,测定种子质量、种子长、种子宽、紧致度、长宽比、形数、种子含水量等7个性状,并采用显著性差异分析、相关性分析及主成分隶属函数法等方法进行统计分析。差异性分析显示,不同样品各个性状间有一定差异,不同性状间的变异程度也不相同;相关性分析显示,各指标之间存在一定的联系,种子性状间不是独立的。根据主成分分析结果,提取了3个主成分,累计贡献率83.235%,第1主成分主要代表种子宽、长宽比、紧致度和形数,第2主成分主要代表种子长、紧致度和形数,第3主成分主要代表了种子质量和含水量。根据主成分的得分进行隶属函数分析,得出33个咖啡种子的性状综合评价值,其中位列前5的依次是编号18、20、23、27、28,即T5175(临沧幸福镇)、爱伲CV-19(普洱)、瑰夏(临沧幸福镇)、瑰夏–圆(临沧幸福镇)、爱伲C36(普洱)。咖啡种子性状都具有丰富的变异性,种源间形态差异较大。从综合评价结果得出,各种植区的咖啡豆大小不一,在同一地点种植的不同咖啡品种各性状间也存在差异。在咖啡推广种植时,应该注意种植品种的选择。 展开更多
关键词 咖啡种子 表型性状 主成分分析 隶属函数法 差异显著性分析 相关性分析
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