期刊文献+
共找到1,028,428篇文章
< 1 2 250 >
每页显示 20 50 100
Evaluation of the protective effects of Crocus sativus L.against cypermethrin induced reproductive toxicity in male rats through the Nrf2 pathway and in silico ADMET analysis
1
作者 Fareena Tariq Farah Ijaz +9 位作者 Yasameen Hameed Jasim Farah Naz Channa Sohail Ahmed Ahmed Shandookh Hameed Sobia Alyas Ahmed Raheem Rayshan Tahira Bibi Nazima Yousaf Khan Sadia Bibi Jameel Ahmed Buzdar 《Traditional Medicine Research》 2026年第3期12-25,共14页
Background:Epidemiological studies have confirmed that longer exposure to insecticides like cypermethrin(CYP)significantly increases the risk of male reproductive toxicity.Crocus sativus L.has been recognized due to i... Background:Epidemiological studies have confirmed that longer exposure to insecticides like cypermethrin(CYP)significantly increases the risk of male reproductive toxicity.Crocus sativus L.has been recognized due to its therapeutic properties,but its exact role and molecular mechanisms in treatment of reproductive dysfunction remain unclear.Methods:During this study,36 rats were randomly divided into six groups(n=6):control,CYP-induced(60 mg/kg),standard(leuprolide 3 mg/kg)and three treatment groups receiving aqueous,ethanolic,and oil extracts(50 mg/kg or 20 mL/kg)for post-toxicity induction.Results:The finding represented that exposure of CYP significantly increased oxidative stress,disrupted testicular architecture,and markedly reduced testosterone levels(P<0.05).Importantly,Crocus sativus L.treatment alleviated these changes by increasing the expression of Nrf2(nuclear factor erythroid 2-related factor 2),restoring the activity of antioxidant enzymes,and enhancing testicular histomorphology.Surprisingly,molecular docking established a high binding affinity of Crocus sativus L.phytoconstituents such as gallic acid,cinnamic acid and quercetin to the Nrf2-Keap1 complex.It is worth noting that,Crocus sativus L.exhibited a high level of protection against reproductive toxicity caused by CYP in male rats,which was mediated by the activation of Nrf2 pathway,reduction of oxidative damage,and favorable ADMET characteristics.Conclusion:Notably,this research provides a more valid,safe,and effective method of developing new drugs for reproductive disorders,however,further investigation is needed to support the research findings and implement it in clinical practice. 展开更多
关键词 Crocus sativus L. CYPERMETHRIN male reproductive toxicity Nrf2 pathway in silico ADMET analysis
暂未订购
Changes in border-associated macrophages after stroke: Single-cell sequencing analysis
2
作者 Ning Yu Yang Zhao +3 位作者 Peng Wang Fuqiang Zhang Cuili Wen Shilei Wang 《Neural Regeneration Research》 2026年第1期346-356,共11页
Border-associated macrophages are located at the interface between the brain and the periphery, including the perivascular spaces, choroid plexus, and meninges. Until recently, the functions of border-associated macro... Border-associated macrophages are located at the interface between the brain and the periphery, including the perivascular spaces, choroid plexus, and meninges. Until recently, the functions of border-associated macrophages have been poorly understood and largely overlooked. However, a recent study reported that border-associated macrophages participate in stroke-induced inflammation, although many details and the underlying mechanisms remain unclear. In this study, we performed a comprehensive single-cell analysis of mouse border-associated macrophages using sequencing data obtained from the Gene Expression Omnibus(GEO) database(GSE174574 and GSE225948). Differentially expressed genes were identified, and enrichment analysis was performed to identify the transcription profile of border-associated macrophages. CellChat analysis was conducted to determine the cell communication network of border-associated macrophages. Transcription factors were predicted using the ‘pySCENIC' tool. We found that, in response to hypoxia, borderassociated macrophages underwent dynamic transcriptional changes and participated in the regulation of inflammatory-related pathways. Notably, the tumor necrosis factor pathway was activated by border-associated macrophages following ischemic stroke. The pySCENIC analysis indicated that the activity of signal transducer and activator of transcription 3(Stat3) was obviously upregulated in stroke, suggesting that Stat3 inhibition may be a promising strategy for treating border-associated macrophages-induced neuroinflammation. Finally, we constructed an animal model to investigate the effects of border-associated macrophages depletion following a stroke. Treatment with liposomes containing clodronate significantly reduced infarct volume in the animals and improved neurological scores compared with untreated animals. Taken together, our results demonstrate comprehensive changes in border-associated macrophages following a stroke, providing a theoretical basis for targeting border-associated macrophages-induced neuroinflammation in stroke treatment. 展开更多
关键词 border-associated macrophages CLODRONATE hypoxia ISCHEMIA-REPERFUSION ischemic stroke liposomes neuroinflammation single-cell sequencing analysis STAT3 tumor necrosis factor
暂未订购
PCA尺度对地铁站建成环境与客流关联影响研究 被引量:1
3
作者 卢源 赵瑾 姚轶峰 《都市快轨交通》 北大核心 2025年第1期30-36,共7页
地铁站点周边建成环境影响客流量,但行人集水区(pedestrian catchment area,PCA)大小尚未统一。本研究旨在验证PCA大小是否影响地铁客流与建成环境相关性研究的结果值。以南宁市轨道交通1号线25个站点为例,选取居住人口、工作岗位、商... 地铁站点周边建成环境影响客流量,但行人集水区(pedestrian catchment area,PCA)大小尚未统一。本研究旨在验证PCA大小是否影响地铁客流与建成环境相关性研究的结果值。以南宁市轨道交通1号线25个站点为例,选取居住人口、工作岗位、商业设施等5个指标作为自变量,站点实际乘客量作因变量。采用OLS回归模型,对比不同PCA半径变量下模型拟合和影响因素的分析结果。地铁站点PCA不同范围的数据收集,对客流量与建成环境关系研究结果存在影响。针对南宁市,其PCA的半径取值为600 m,在地铁客流与建成环境相关性模型的拟合好于300 m和900 m。PCA范围会导致地铁客流与建成环境关联研究结果不一致。未来相关研究需针对不同PCA半径进行模型分析,根据拟合效果确定适宜的PCA尺度,提高研究准确性。 展开更多
关键词 城市轨道交通 行人集水区(pca) 回归模型 建成环境 客流 南宁市
在线阅读 下载PDF
应用二维经验模分解(2D-EMD)-主成分分析(PCA)组合模型定量圈定与评价胶东金与关键金属找矿靶区
4
作者 陈永清 郑澳月 +2 位作者 费金娜 赵婕 赵鹏大 《地学前缘》 北大核心 2025年第1期266-282,共17页
近年来,随着制造业和全球经济发展,全球对矿产资源的需求量大幅上升,迫切需要研究和开发新方法来勘探未发现矿产资源。然而,多阶段的成矿作用使成矿元素在地质单元内的分布呈现出复杂的叠加特征,而且大多数矿产常常伴生多种元素。本研... 近年来,随着制造业和全球经济发展,全球对矿产资源的需求量大幅上升,迫切需要研究和开发新方法来勘探未发现矿产资源。然而,多阶段的成矿作用使成矿元素在地质单元内的分布呈现出复杂的叠加特征,而且大多数矿产常常伴生多种元素。本研究将二维经验模分解(2D-EMD)与主成分分析(PCA)相结合,基于胶东金多金属矿集区水系沉积物地球化学数据,提取局部和区域多元素组合异常分量,从多阶段成矿过程产生的复杂叠加异常中识别找矿靶区。研究结果表明:(1)通过PCA建立了Au-Ag-Cd和Be-La-Mo-Nb-Th-U-Y两种多元素组合;(2)应用2D-EMD从主成分得分分别识别多元素成矿组合局部和区域异常分量;(3)局部异常分量可用于识别Au-Ag-Cd和Be-La-Mo-Nb-Th-U-Y找矿靶区,区域异常分量可识别高背景带。结合局部异常分量和花岗岩的空间分布,推断Au-Ag-Cd矿化与玲珑花岗岩和郭家岭花岗闪长岩侵入有关,Be-La-Mo-Nb-Th-U-Y矿化与郭家岭花岗闪长岩侵入体和伟德山二长岩侵入体侵入有关,郭家岭花岗闪长岩岩体具有贵金属和关键金属双重成矿特征。 展开更多
关键词 2D-EMD pca 多元素组合异常分量 胶东金多金属矿集区
在线阅读 下载PDF
基于PCA-Logistic回归模型的图像过曝光区域检测方法
5
作者 陈涛 符均 +1 位作者 丁子硬 陈希 《制造业自动化》 2025年第4期40-47,共8页
针对过曝光区域检测问题,提出了一种基于主成分分析(Principal Components Analysis,PCA)和Logistic回归的过曝光图像饱和像素检测方法。首先通过研究分析过曝光图像的显著性特征,提取了亮度及颜色特征、人类视觉修正的饱和度特征、空... 针对过曝光区域检测问题,提出了一种基于主成分分析(Principal Components Analysis,PCA)和Logistic回归的过曝光图像饱和像素检测方法。首先通过研究分析过曝光图像的显著性特征,提取了亮度及颜色特征、人类视觉修正的饱和度特征、空间邻域特征、局部熵特征、灰度对比度特征等变量作为检测图像过曝光的初始指标;接着利用主成分分析方法对原始指标变量进行降维处理,然后利用建立的L2正则化的Logistic回归模型进行分析预测;最后与其他过曝光检测算法进行了对比分析,并在某安防监控图像中进行了过曝光区域检测效果验证。结果表明,该模型检测结果更具整体性,检测区域更紧凑,也更符合人眼对过曝光区域的视觉感知。 展开更多
关键词 过曝光图像 饱和像素检测 主成分分析(pca) LOGISTIC回归分析
在线阅读 下载PDF
基于PCA-TOPSIS法的物流管理专业学生实践能力评价
6
作者 邹浩 李燕 +2 位作者 杨鹏 唐力翔 袁倩茹 《物流工程与管理》 2025年第2期156-159,共4页
学生实践应用能力是优化学习效果、解决社会问题、满足行业需求等的关键能力。从个人综合素质、学校内部因素、外部环境因素三方面构建了物流管理专业学生实践应用能力评估指标体系,并结合PCA和TOPSIS法对学生实践应用能力进行评估、排... 学生实践应用能力是优化学习效果、解决社会问题、满足行业需求等的关键能力。从个人综合素质、学校内部因素、外部环境因素三方面构建了物流管理专业学生实践应用能力评估指标体系,并结合PCA和TOPSIS法对学生实践应用能力进行评估、排序,最后通过数值算例验证了该方法的可行性。 展开更多
关键词 物流管理专业 实践应用能力 pca TOPSIS 综合评估
在线阅读 下载PDF
基于PCA-BP神经网络的应急响应物资精准需求预测模型构建——以地震灾害响应初期的灾民生活物资需求为例
7
作者 李尧远 曲政澍 《灾害学》 北大核心 2025年第4期31-36,共6页
为提升灾害应急响应能力,实现响应初期应急物资精准供给,保障灾民基本生活需求,该文以我国部分地震灾害为例,收集地震数据,以紧急转移安置人口数量为预测目标,选取相关地震指标为影响因素,构建基于主成分分析(PCA)与反向传播(BP)神经网... 为提升灾害应急响应能力,实现响应初期应急物资精准供给,保障灾民基本生活需求,该文以我国部分地震灾害为例,收集地震数据,以紧急转移安置人口数量为预测目标,选取相关地震指标为影响因素,构建基于主成分分析(PCA)与反向传播(BP)神经网络的紧急转移安置人口数量预测模型。在此基础上,结合紧急转移安置人口数量与灾民生活物资需求的关系,建立物资需求预测模型。结果表明:该模型在在紧急转移安置人口预测方面具有更高的精度,能够较为准确估算紧急转移安置人口数量;在生活物资需求预测方面,经算例验证,该模型具备一定实践价值,可为应急响应初期的物资配置决策提供科学依据。 展开更多
关键词 应急响应 需求预测 地震 主成分分析法(pca) 反向(BP)神经网络
在线阅读 下载PDF
基于PCA-RF预测方便米饭品质模型的建立
8
作者 周显青 康招阳 +2 位作者 韩佳静 闫会杰 冯萧雨 《河南工业大学学报(自然科学版)》 北大核心 2025年第2期87-95,共9页
为了改善方便米饭在加工过程中品质不稳定的问题,缩短产品研发周期,采用主成分分析法(PCA)对方便米饭的外观品质(L^(*)、a^(*)、b^(*)、W、孔隙率、比容)、质构特性(硬度、黏性、弹性、咀嚼性、内聚性、回复性)、感官评价(气味、色泽、... 为了改善方便米饭在加工过程中品质不稳定的问题,缩短产品研发周期,采用主成分分析法(PCA)对方便米饭的外观品质(L^(*)、a^(*)、b^(*)、W、孔隙率、比容)、质构特性(硬度、黏性、弹性、咀嚼性、内聚性、回复性)、感官评价(气味、色泽、完整性、黏性、弹性、软硬度、总分)进行降维分类处理,然后利用降维后的数据以工艺参数为输入变量,综合评分为输出变量,建立随机森林(RF)预测模型;采用均方误差(MSE)、平均绝对误差(MAE)以及决定系数(R^(2))评价回归预测模型的准确性以及模型对数据的拟合程度。结果表明:经过PCA降维后,方便米饭品质可分为优(1~<2)、良(0~<1)、中(-1~<0)、差(-2~<-1)4类;当RF算法中决策树的棵数为800,最大深度为5时,PCA-RF预测模型的预测误差最小、精度最高;PCA法降维得到的预测模型预测准确率优于LDA法;与PCA-BP、PCA-PLS和PCA-ELM预测模型相比,PCA-RF预测模型的MAE、MSE均最小,R^(2)为0.898,高于其他3种模型。所建立的PCA-RF模型预测效果好、误差小、精度高,具备较好的学习能力与泛化能力,可为方便米饭工业化生产的质量控制提供参考。 展开更多
关键词 大米 品质分析 数学建模 随机森林 pca
在线阅读 下载PDF
基于PCA的短跑运动员起跑蹬腿动作特征提取方法
9
作者 沈营 章明辉 《河南财政金融学院学报(自然科学版)》 2025年第2期69-74,共6页
以提高短跑运动员起跑速度为目标,提出基于PCA的短跑运动员起跑蹬腿动作特征提取方法,降低特征提取的误差。选取含有CMOS传感器组件摄像头的机器视觉系统,采集短跑运动员的起跑蹬腿动作图像;利用LBP算法构建动作识别模型,通过对比图像... 以提高短跑运动员起跑速度为目标,提出基于PCA的短跑运动员起跑蹬腿动作特征提取方法,降低特征提取的误差。选取含有CMOS传感器组件摄像头的机器视觉系统,采集短跑运动员的起跑蹬腿动作图像;利用LBP算法构建动作识别模型,通过对比图像各像素灰度值与邻域像素灰度,获取图像灰度区间内的纹理信息,经直方图转换后,形成LBP动作样本特征矩阵;通过PCA算法K-L变换降低特征矩阵维数,通过“平均脸”法获取动作图像的“平均动作”,实现动作的特征提取。实验结果表明,该方法可有效提取起跑运动员起跑蹬腿动作特征,识别最大误差率不超过3.5%。 展开更多
关键词 短跑运动员 起跑蹬腿 动作特征 特征提取 pca算法 旋转不变性 特征矩阵
在线阅读 下载PDF
Tool Health Condition Recognition Method for High Speed Milling of Titanium Alloy Based on Principal Component Analysis(PCA)and Long Short Term Memory(LSTM) 被引量:2
10
作者 YANG Qirui XU Kaizhou +2 位作者 ZHENG Xiaohu XIAO Lei BAO Jinsong 《Journal of Donghua University(English Edition)》 EI CAS 2019年第4期364-368,共5页
The healthy condition of the milling tool has a very high impact on the machining quality of the titanium components.Therefore,it is important to recognize the healthy condition of the tool and replace the damaged cut... The healthy condition of the milling tool has a very high impact on the machining quality of the titanium components.Therefore,it is important to recognize the healthy condition of the tool and replace the damaged cutter at the right time.In order to recognize the health condition of the milling cutter,a method based on the long short term memory(LSTM)was proposed to recognize tool health state in this paper.The various signals collected in the tool wear experiments were analyzed by time-domain statistics,and then the extracted data were generated by principal component analysis(PCA)method.The preprocessed data extracted by PCA is transmitted to the LSTM model for recognition.Compared with back propagation neural network(BPNN)and support vector machine(SVM),the proposed method can effectively utilize the time-domain regulation in the data to achieve higher recognition speed and accuracy. 展开更多
关键词 HEALTH CONDITION recognition MILLING TOOL principal component analysis(pca) long short TERM memory(LSTM)
在线阅读 下载PDF
PCA-SVM算法在智能访客人脸识别系统中的应用及性能优化
11
作者 刘敏 丁俊美 +1 位作者 周沭玲 豆利 《电脑知识与技术》 2025年第3期24-26,38,共4页
文章研究了基于主成分分析(PCA)和支持向量机(SVM)算法的智能访客人脸识别系统。通过图像预处理、PCA降维和SVM分类,构建了一个优化模型。实验结果表明,该模型在ORL和自建数据集上均取得了比传统PCA方法更高的识别率和更快的匹配速度,... 文章研究了基于主成分分析(PCA)和支持向量机(SVM)算法的智能访客人脸识别系统。通过图像预处理、PCA降维和SVM分类,构建了一个优化模型。实验结果表明,该模型在ORL和自建数据集上均取得了比传统PCA方法更高的识别率和更快的匹配速度,有效降低了误报率,为智能访客系统的性能提升提供了技术支持。 展开更多
关键词 pca SVM 访客系统 优化 人脸识别
在线阅读 下载PDF
The PCA3 test for guiding repeat biopsy of prostate cancer and its cut-off score: a systematic review and meta-analysis 被引量:13
12
作者 Yong Luo Xin Gou Peng Huang Chan Mou 《Asian Journal of Andrology》 SCIE CAS CSCD 2014年第3期487-492,共6页
The specificity of prostate-specific antigen (PSA) for early intervention in repeat biopsy is unsatisfactory. Prostate cancer antigen 3 (PCA3) may be more accurate in outcome prediction than other methods for the ... The specificity of prostate-specific antigen (PSA) for early intervention in repeat biopsy is unsatisfactory. Prostate cancer antigen 3 (PCA3) may be more accurate in outcome prediction than other methods for the early detection of prostate cancer (PCa). However, the results were inconsistent in repeated biopsies. Therefore, we performed a systematic review and meta-analysis to evaluate the role of PCA3 in outcome prediction. A systematic bibliographic search was conducted for articles published before April 2013, using PubMed, Medline, Web of Science, Embase and other databases from health technology assessment agencies. The quality of the studies was assessed on the basis of QUADAS criteria. Eleven studies of diagnostic tests with moderate to high quality were selected. A meta-analysis was carried out to synthesize the results. The results of the meta-analyses were heterogeneous among studies. We performed a subgroup analysis (with or without inclusion of high-grade prostatic intraepithelial neoplasia (HGPIN) and atypical small acinar proliferation (ASAP)). Using a PCA3 cutoff of 20 or 35, in the two sub-groups, the global sensitivity values were 0.93 or 0.80 and 0.79 or 0.75, specificities were 0.65 or 0.44 and 0.78 or 0.70, positive likelihood ratios were 1.86 or 1.58 and 2.49 or 1.78, negative likelihood ratios were 0.81 or 0.43 and 0.91 or 0.82 and diagnostic odd ratios (ORs) were 5.73 or 3.45 and 7.13 or 4.11, respectively. The areas under the curve (AUCs) of the summary receiver operating characteristic curve were 0.85 or 0.72 and 0.81 or 0.69, respectively. PCA3 can be used for repeat biopsy of the prostate to improve accuracy of PCa detection. Unnecessary biopsies can be avoided by using a PCa cutoff score of 20. 展开更多
关键词 META-analysis pca3 prostate cancer repeat biopsy systematic review
在线阅读 下载PDF
应用奇异值分解(SVD)-主成分分析(PCA)组合模型定量圈定与评价腾冲地块锡钨和铅锌多金属找矿靶区 被引量:3
13
作者 郑澳月 费金娜 +3 位作者 陈永清 宁妍云 曹一琳 赵鹏大 《地学前缘》 北大核心 2025年第1期283-301,共19页
成矿元素或元素组在一个地质单元中的富集是成岩和成矿地质过程多阶段作用的产物。基于水系沉积物地球化学数据,主成分分析(principal component analysis,PCA)可识别成矿元素组。奇异值分解(singular value decomposition,SVD)可将成... 成矿元素或元素组在一个地质单元中的富集是成岩和成矿地质过程多阶段作用的产物。基于水系沉积物地球化学数据,主成分分析(principal component analysis,PCA)可识别成矿元素组。奇异值分解(singular value decomposition,SVD)可将成矿元素组主成分得分进一步分解为两个部分:(1)成矿元素组合区域异常分量,能够表征在地壳演化过程中,由各种地质作用(岩浆作用、沉积作用和/或变质作用)形成的有利于成矿的高背景区域;(2)成矿元素组合局部异常分量,能够表征成矿作用引起的,叠加在成矿元素组合区域异常分量之上的成矿元素组合局部异常分量,应用局部异常分量能够识别找矿靶区。本次研究,首先基于国家1∶200000水系沉积物地球化学数据,应用主成分分析建立不同类型的成矿元素组;其次,利用SVD从成矿元素组的主成分得分中识别出不同类型成矿过程引起的成矿元素组合局部异常分量;最后,应用局部异常分量识别找矿靶区。最终在腾冲地块圈定15处找矿靶区,其中Sn-W找矿靶区8处,Pb-Zn-Ag找矿靶区7处。预测Sn-W潜在资源量915 Mt,Pb-Zn-Ag潜在资源量792 Mt。 展开更多
关键词 SVD pca 成矿元素组合异常分量 地球化学块体 锡钨和铅锌多金属矿 腾冲地块 西南地区
在线阅读 下载PDF
Degradation of malathion by Pseudomonas during activated sludge treatment system using principal component analysis (PCA) 被引量:3
14
作者 Hashmi Imran Khan M Altaf Kim Jong-Guk 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2006年第4期797-804,共8页
Popular descriptive multivariate statistical method currently employed is the principal component analyses (PCA) method. PCA is used to develop linear combinations that successively maximize the total variance of a ... Popular descriptive multivariate statistical method currently employed is the principal component analyses (PCA) method. PCA is used to develop linear combinations that successively maximize the total variance of a sample where there is no known group structure. This study aimed at demonstrating the performance evaluation of pilot activated sludge treatment system by inoculating a strain of Pseudomonas capable of degrading malathion which was isolated by enrichment technique. An intensive analytical program was followed for evaluating the efficiency of biosimulator by maintaining the dissolved oxygen (DO) concentration at 4.0 mg/L. Analyses by high performance liquid chromatographic technique revealed that 90% of malathion removal was achieved within 29 h of treatment whereas COD got reduced considerably during the treatment process and mean removal efficiency was found to be 78%. The mean pH values increased gradually during the treatment process ranging from 7.36-8.54. Similarly the mean ammonia-nitrogen (NH3-N) values were found to be fluctuating between 19.425-28.488 mg/L, mean nitrite-nitrogen (NO3-N) ranging between 1.301- 2.940 mg/L and mean nitrate-nitrogen (NO3-N) ranging between 0.0071-0.0711 mg/L. The study revealed that inoculation of bacterial culture under laboratory conditions could be used in bioremediation of environmental pollution caused by xenobiotics. The PCA analyses showed that pH, COD, organic load and total malathion concentration were highly correlated and emerged as the variables controlling the first component, whereas dissolved oxygen, NO3-N and NH3-N governed the second component. The third component repeated the trend exhibited by the first two components. 展开更多
关键词 activated sludge system malathion principal component analyses pca raw wastewater removal efficiency
在线阅读 下载PDF
Early Sensor Fault Detection Based on PCA and Clustering Analysis 被引量:2
15
作者 Xue-Bing Gong Ri-Xin Wang Min-Qiang Xu 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2014年第6期113-120,共8页
This paper proposes a novel scoring index for the early sensor fault detection in order to make full use of massive archived spacecraft telemetry data.The early detection of sensor faults is made by using the index co... This paper proposes a novel scoring index for the early sensor fault detection in order to make full use of massive archived spacecraft telemetry data.The early detection of sensor faults is made by using the index constructed by the K-means algorithm and PCA model.The sensor fault detection includes the learning phase and monitoring phase.The amplitude of sensor fault has been always increasing when the performance of sensors deteriorates during a period.The proposed index can detect the smaller sensor faults than the squared prediction error( SPE) index which means it can discover the sensor faults earlier than the later.The simulation results demonstrate the effectiveness and feasibility of the proposed index which can decrease the check-limit as much as 40% than SPE in the same magnitude of bias sensor fault. 展开更多
关键词 early fault detection pca K-means algorithm SPE Sensor faults
在线阅读 下载PDF
Application of exploratory data analysis: HCA and PCA in the classification of bicarbonated and not bicarbonated groundwaters in the Western Amazon Region 被引量:1
16
作者 Francisco S. P. dos Santos Panero Henrique E. B. S. Eduardo Bezerra da Silva Joao S. P. dos Santos Panero 《Chinese Journal Of Geochemistry》 EI CAS 2006年第B08期165-166,共2页
关键词 HCA pca 亚马逊河 地下水 重碳酸盐
在线阅读 下载PDF
Phase Analysis and Identification Method for Multiphase Batch Processes with Partitioning Multi-way Principal Component Analysis (MPCA) Model 被引量:3
17
作者 董伟威 姚远 高福荣 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2012年第6期1121-1127,共7页
Multi-way principal component analysis (MPCA) is the most widely utilized multivariate statistical process control method for batch processes. Previous research on MPCA has commonly agreed that it is not a suitable me... Multi-way principal component analysis (MPCA) is the most widely utilized multivariate statistical process control method for batch processes. Previous research on MPCA has commonly agreed that it is not a suitable method for multiphase batch process analysis. In this paper, abundant phase information is revealed by way of partitioning MPCA model, and a new phase identification method based on global dynamic information is proposed. The application to injection molding shows that it is a feasible and effective method for multiphase batch process knowledge understanding, phase division and process monitoring. 展开更多
关键词 batch process multi-way principal component analysis MULTIPHASE process monitoring
在线阅读 下载PDF
Analysis and Optimisation of Halomonas Growth Factors Based on PCA and RSM 被引量:2
18
作者 Shi Ke Huang Guofu +4 位作者 Xu Huachun Xue Jianliang Sun Jingkuan Xiao Xinfeng Li Lin 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2019年第4期81-87,共7页
The biomass of petroleum-degrading bacteria, such as Halomonas spp., is crucial to the alleviation of severe oil spills through bioremediation. In this paper, the bacterium(HDMP1) was isolated and identified. Growth f... The biomass of petroleum-degrading bacteria, such as Halomonas spp., is crucial to the alleviation of severe oil spills through bioremediation. In this paper, the bacterium(HDMP1) was isolated and identified. Growth factors were analysed and optimised through the single-factor experiments, the factor analysis(FA), the principal component analysis(PCA), and the response surface methodology(RSM). Results indicated that HDMP1 was identified as genus Halomonas. In the single-factor experiments, the range of suitable growth conditions for HDMP1 covered: a salt concentration of 2%-4%, a medium pH value of approximately 9, an inoculum concentration of 1.0%, a substrate concentration of 1.0%-1.4%, and a rotation rate of 140 r/min. The evaluation by FA and PCA indicated that three significant growth factors were the salt concentration, the pH value, and the rotation rate. A maximum biomass of HDMP1 was obtained under the conditions covering a salt concentration of 3.5%, a medium pH of 8, and a rotation rate of 151 r/min by optimization. 展开更多
关键词 BIOMASS factor analysis principal component analysis growth factors response surface methodology
在线阅读 下载PDF
基于CEEMDAN-PCA-AC-CNN模型的离心泵故障识别技术 被引量:1
19
作者 李曈希 刘志龙 +3 位作者 罗骞 曾真 王钦超 聂常华 《核动力工程》 北大核心 2025年第1期265-272,共8页
为确保离心泵的长期健康稳定运行,对其进行在线监测与故障识别显得尤为重要。本文提出了一种基于自适应噪声的集合经验模态分解(CEEMDAN)-主成分分析(PCA)-自相关(AC)-卷积神经网络(CNN)的设备故障识别模型。首先将采集到的振动信号进行... 为确保离心泵的长期健康稳定运行,对其进行在线监测与故障识别显得尤为重要。本文提出了一种基于自适应噪声的集合经验模态分解(CEEMDAN)-主成分分析(PCA)-自相关(AC)-卷积神经网络(CNN)的设备故障识别模型。首先将采集到的振动信号进行CEEMDAN,对得到的内涵模态函数(IMF)分量进行判别,剔除噪声分量,重构第一轮去噪信号。再通过PCA对一轮去噪的信号进行二次降噪处理。然后将经历2次降噪处理后的信号进行AC处理,送入CNN作为输入数据,对模型进行训练。通过对某离心泵故障进行实验验证,结果表明:本文提出的方法相较于传统双层降噪结合CNN的算法、CEEMD-小波降噪-AC-CNN等算法具有更好的抗干扰性能与更快的模型收敛速度,具有更高的识别准确率与更好的鲁棒性,在同等量级下,识别准确率高达97.9%。 展开更多
关键词 自适应噪声的集合经验模态分解(CEEMDAN) 主成分分析(pca) 信号降噪 卷积神经网络(CNN) 故障识别
原文传递
一种改进的K-PCA与PNN结合的快速高光谱遥感分类算法
20
作者 简萌 陈旭凤 +1 位作者 鲁军 郝敏钗 《河北大学学报(自然科学版)》 北大核心 2025年第4期343-351,共9页
高光谱遥感数据可以提供更加丰富的地物信息,但因其数据维度高、冗余性强等特点导致传统分类方法效率低下.针对此问题本文提出一种改进的核-主成分分析(kernel-principalcomponentanalysis,K-PCA)与概率神经网络(probabilisticneuralnet... 高光谱遥感数据可以提供更加丰富的地物信息,但因其数据维度高、冗余性强等特点导致传统分类方法效率低下.针对此问题本文提出一种改进的核-主成分分析(kernel-principalcomponentanalysis,K-PCA)与概率神经网络(probabilisticneuralnetwork,PNN)结合的快速高光谱遥感分类算法.首先提出一种最近邻的样本选择方法,用以筛选更具代表性的地物光谱数据;其次提出一种基于半数重采样的主成分优选策略,有效去除噪声并保留光谱本质特征,大幅度降低数据维度;最后融合K-PCA的非线性降维特性与PNN的最优贝叶斯分类能力进行地物识别.在利用AVIRIS高光谱数据集的验证实验中,本算法不仅将分类精度提升至89.9%,较传统方法提升显著,且运算效率大幅提升.结果表明该算法在兼顾分类精度与实时性的高光谱地物识别场景中凸显优势,为遥感大数据智能处理提供了高效解决方案. 展开更多
关键词 高光谱遥感数据 地物识别 核-主成分分析 概率神经网络 半数重采样
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部