Z-score and Cluster Analysis in Assessment of Comprehensive Detection Ability of Tobacco Chemical Composition
In order to explore the similarities and differences in evaluation of Single Index by different Z-Score methods,and to solve the problem that the Z-Score cannot satisfy the comprehensive evaluation of multiple indicators.This article takes the verification of the ability to detect the conventional chemical composition of tobacco leaves as a scenario.On one hand,it compares the similarities and differences between the conventional Z-Score and the robust Z-Score in the single index detection ability evaluation,and to evaluate which one is preferred;on the other hand,the combination of Z-Score and principal component analysis and cluster analysis establishes a multi-index comprehensive evaluation method.The evaluation results show that:(1)In the single-index ability evaluation,the laboratory satisfaction rate obtained by the conventional Z-Score and the robust Z-Score is over 85%;(2)The correlation coefficient of two Z-Score is more than 99.90%,and the followability is better;(3)The robust Z-Score is more convenient to calculate and has better applicability under different data distribution forms,while the conventional Z-Score has high applicability when the data comply with abnormal distribution;(4)The combination of Z-Score and cluster analysis can effectively divide 40 laboratories into 6 classes,but more than 80%of laboratories are included in first class;(5)Conventional Z ratio scores with principal component extraction followed by clustering can improve the degree of class-to-class separation and the distinctiveness of class characteristics.Such as,the first and second class are satisfied with the ability verification,but slightly low or high,the third,fourth,fifth,and sixth class represent an unsatisfactory index respectively.
万方数据
维普
