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多重最小成分的神经网络算法及其在曲线拟合中的应用 被引量:2
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作者 董天信 姜玉英 徐宗本 《西安交通大学学报》 EI CAS CSCD 北大核心 2003年第2期205-207,共3页
讨论了空间曲线的拟合问题与多重最小成分抽取问题的等价性,提出了多重最小成分抽取的无导师、自适应神经网络学习算法,该算法为Oja算法的一种改进,没有任何附加条件.数学分析的结果表明,该算法是一种高效、可靠的多重最小成分的抽取方... 讨论了空间曲线的拟合问题与多重最小成分抽取问题的等价性,提出了多重最小成分抽取的无导师、自适应神经网络学习算法,该算法为Oja算法的一种改进,没有任何附加条件.数学分析的结果表明,该算法是一种高效、可靠的多重最小成分的抽取方法,特别可用于空间曲线的拟合. 展开更多
关键词 神经网络 最小成分分析 空间曲线拟合 自适应学习算法 最小成分抽取 Oja算法
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基于主成分分析的黄土沟壑区土壤肥力质量评价——以长武县耕地土壤为例 被引量:82
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作者 黄婷 岳西杰 +1 位作者 葛玺祖 王旭东 《干旱地区农业研究》 CSCD 北大核心 2010年第3期141-147,187,共8页
以陕西省长武县所处的黄土高原沟壑区土壤为研究对象,通过主成分分析并结合Norm值的方法,筛选出活性有机质、全氮、速效磷、速效钾、粘粒、CEC、过氧化氢酶、磷酸酶和转化酶等12项指标,建立了黄土沟壑区土壤综合质量评价的最小数据集(M... 以陕西省长武县所处的黄土高原沟壑区土壤为研究对象,通过主成分分析并结合Norm值的方法,筛选出活性有机质、全氮、速效磷、速效钾、粘粒、CEC、过氧化氢酶、磷酸酶和转化酶等12项指标,建立了黄土沟壑区土壤综合质量评价的最小数据集(MDS)。采用客观方法(主成分分析法)以及主客观相结合的方法确定了两种类型的权重系数,分别计算了土壤综合质量指数,发现两种方法计算所得的土壤综合质量指数之间具有很好的一致性。另外,把由主成分分析法计算的土壤综合质量指数与利用偏相关系数法计算出的土壤综合质量指数进行了线性回归分析,两者之间达到极显著相关,说明用主成分分析法在该地区进行土壤质量综合评价是客观可行的。各因子的隶属度表明,活性有机质是该地区主要的限制性因子,全氮次之。几种不同方法计算的土壤质量表明,果园土壤质量优于农田土壤的,不同地形部位土壤质量比较发现,塬面的土壤质量相对最高,坡地(梯田)次之,河滩地相对最低。 展开更多
关键词 土壤质量评价 成分分析 最小数据集 权重确定 黄土沟壑区
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基于K近邻互信息估计的EEG伪迹消除方法 被引量:5
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作者 何海洋 罗志增 《计算机工程》 CAS CSCD 2013年第6期255-260,共6页
针对脑电信号中的眼电和心电串扰伪迹,提出一种基于最小相依成分分析的互信息(MILCA)算法的伪迹消除方法。在提升小波硬阈值法对多路原始脑电信号去噪基础上,运用MILCA算法对各通道信号进行盲源分离,同时采用信号间互相关系数和互信息... 针对脑电信号中的眼电和心电串扰伪迹,提出一种基于最小相依成分分析的互信息(MILCA)算法的伪迹消除方法。在提升小波硬阈值法对多路原始脑电信号去噪基础上,运用MILCA算法对各通道信号进行盲源分离,同时采用信号间互相关系数和互信息量作为指标,分析伪迹分离程度。与Extend Infomax、FastICA 2种常见盲源分离算法的对比结果表明,运用MILCA算法对脑电信号中的眼电及心电伪迹的分离结果最理想。 展开更多
关键词 脑电信号 盲源分离 K近邻 互信息 最小相依成分分析
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1~H NMR-based serum metabolic profiling in compensatedand decompensated cirrhosis 被引量:10
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作者 Su-Wen Qi Zhi-Guang Tu +4 位作者 Wu-Jian Peng Lin-Xian Wang Xin Ou-Yang An-Ji Cai Yong Dai 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第3期285-290,共6页
AIM: To study the metabolic profiling of serum samples from compensated and decompensated cirrhosis patients. METHODS: A pilot metabolic profiling study was conducted using three groups: compensated cirrhosis patients... AIM: To study the metabolic profiling of serum samples from compensated and decompensated cirrhosis patients. METHODS: A pilot metabolic profiling study was conducted using three groups: compensated cirrhosis patients (n = 30), decompensated cirrhosis patients (n = 30) and healthy controls (n = 30). A 1H nuclear magnetic resonance (NMR)-based metabonomics approach was used to obtain the serum metabolic profiles of the samples. The acquired data were processed by multivariate principal component analysis and orthogonal partial least-squares discriminant analysis (OPLS-DA). RESULTS: The OPLS-DA model was capable of distinguishing between decompensated and compensated cirrhosis patients, with an R2Y of 0.784 and a Q2Y of 0.598. Twelve metabolites, such as pyruvate, phenylala-nine and succinate, were identified as the most influential factors for the difference between the two groups. The validation of the diagnosis prediction showed that the accuracy of the OPLS-DA model was 85% (17/20). CONCLUSION: 1H NMR spectra combined with pattern recognition analysis techniques offer a new way to diagnose compensated and decompensated cirrhosis in the future. 展开更多
关键词 Liver cirrhosis Metabolic profiling Orthogo- nal partial least-squares discriminant analysis
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MIMO Soft-sensor Model of Nutrient Content for Compound Fertil- izer Based on Hybrid Modeling Technique 被引量:6
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作者 傅永峰 苏宏业 褚健 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2007年第4期554-559,共6页
In compound fertilizer production, several quality variables need to be monitored and controlled simultaneously. It is very diifficult to measure these variables on-line by existing instruments and sensors. So, soft-s... In compound fertilizer production, several quality variables need to be monitored and controlled simultaneously. It is very diifficult to measure these variables on-line by existing instruments and sensors. So, soft-sensor technique becomes an indispensable method to implement real-time quality control. In this article, a new model of multi-inputs multi-outputs (MIMO) soft-sensor, which is constructed based on hybrid modeling technique, is proposed for these interactional variables. Data-driven modeling method and simplified first principle modelingmethod are combined in this model. Data-driven modeling method based on limited memory partial least squares(LM-PLS) al.gorithm is used to build soft-senor models for some secondary variables.then, the simplified first principle model is used to compute three primary variables on line. The proposed model has been used in practicalprocess; the results indicate that the proposed model is precise and efficient, and it is possible to realize on line quality control for compound fertilizer process. 展开更多
关键词 multi-inputs multi-outputs soft-sensor limited memory partial least squares simplified first principle model nutrient content of compound fertilizer
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Winners and losers among tree species in Xishuangbanna: which traits are most important? 被引量:1
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作者 赵美玲 潘勃 +1 位作者 谭运洪 Richard T.Corlett 《Science Bulletin》 SCIE EI CAS CSCD 2015年第10期916-924,I0007,共10页
Massive human interference in natural ecosystems is resulting in a few "winners" and many "losers". However, the drivers of this winner-loser replacement pattern remain poorly understood. The aim of the study repo... Massive human interference in natural ecosystems is resulting in a few "winners" and many "losers". However, the drivers of this winner-loser replacement pattern remain poorly understood. The aim of the study reported here was to identify winners among the tree flora of Xishuangbanna and compare their functional traits, specific leaf area (SLA), wood density (WD), seed mass (SM) and maximum height (MH) with previously identified losers (i.e., endangered species). Fifteen native tree species were identified as winners from expert opinion, plot-based surveys of secondary forests and plotless surveys along roads. Twelve endangered tree species for which trait information could be obtained were used for comparison. Traits were compared with a Wilcoxon rank-sum test. Winners had significantly higher SLA, but lower WD. SM and MH did not differ significantly between groups. When the effects of phylogeny were removed by using phylogenetic generalized least squares, the difference in SLA became marginally insignificant. Principal component analysis resulted in two overlapping groups, showing that the selected traits were insufficient to distinguish winners and losers. Our results suggest that the "few winners, many losers" paradigm applies to trees in Xishuangbanna, with15 species accounting for most trees in the disturbed habitats sampled. 展开更多
关键词 Human disturbance - Functional traits Phylogeny Conservation status Tropical forests
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Visual tracking based on the sparse representation of the PCA subspace
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作者 陈典兵 朱明 王慧利 《Optoelectronics Letters》 EI 2017年第5期392-396,共5页
We construct a collaborative model of the sparse representation and the subspace representation. First, we represent the tracking target in the principle component analysis(PCA) subspace, and then we employ an L_1 reg... We construct a collaborative model of the sparse representation and the subspace representation. First, we represent the tracking target in the principle component analysis(PCA) subspace, and then we employ an L_1 regularization to restrict the sparsity of the residual term, an L_2 regularization term to restrict the sparsity of the representation coefficients, and an L_2 norm to restrict the distance between the reconstruction and the target. Then we implement the algorithm in the particle filter framework. Furthermore, an iterative method is presented to get the global minimum of the residual and the coefficients. Finally, an alternative template update scheme is adopted to avoid the tracking drift which is caused by the inaccurate update. In the experiment, we test the algorithm on 9 sequences, and compare the results with 5 state-of-art methods. According to the results, we can conclude that our algorithm is more robust than the other methods. 展开更多
关键词 Distributed computer systems Principal component analysis
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