Principal component analysis Principal-component analysis 16 principal component analysis 16 Quality control 13 China 8 human 8 Humans 7 Article 6 Cluster analysis 6 Principal Component Analysis 6 Regression analysis 6 Discriminant analysis 5 Learning algorithms 5 Multivariant analysis 5 adult 5 controlled study 5 female 5 male 5 Digital storage 4 Ecology 4 Ecosystems 4 Factor analysis 4 Proteins 4 Risk assessment 4 Spatial variables measurement 4 Support vector machines 4 Water quality 4 Amino acids 3 BP neural networks 3 Decision trees 3