Semisupervisedmakesfulluseoflargeamountsofunlabeledsamplestomakeuptheinsufficiency of labeled samples. Since it is difficult to obtain a large number of accurate labeled samples and it is a good way for modeling by using a small amount of labeled samples or a large number of inaccurate samples, we proposed a new method named as semi-supervised partial least squares ( SS-PLS) to optimize model based on semi supervised learning. We used 211 samples of tobacco near infrared spectrum and sensory evaluation for modeling and used SS-PLS method to optimize tobacco sensory evaluation model. In the optimized model, the coefficient of determination ( R2 ) can reach up to 90%, the ratio of performance to deviation ( RPD) can reach up to 3 . 0 , and the standard error of cross validation and the standard error of prediction ( SECV and SEP) are below 1. 0. We divided the original sensory evaluation and SS-PLS optimized data into three grades of excellent, medium and poor in accordance with the fixed threshold, the result using projection model of based on principal component and Fisher criterion ( PPF ) shows that the classification of SS-PLS optimized data is better than the original sensory evaluation data. The SS-PLS method can solve the data representation problem of using small sample set for modeling and provides a new chemometrics method for near infrared spectroscopy modeling in case of obtaining a large number of accurately labeled samples is difficult.

Objective:According to the requirements set forth by the " regulations on the management of drug clinical trial institutions" and the 2020 version of Good Clinical Practice, problems faced by the construction of Institutional Review Board (hereinafter referred to as the IRB) in the implementation of the filing system is solved.Methods:According to the study of laws and regulations, combined with problem analysis during the early construction of IRB, problems during the IRB filing are identified and analyzed.Results:The IRB faced many problems that including the organizational structure, continuing review, informed consent and multicenter ethical review. We can gradually improve the ability of ethical review through continuous in-depth study of relevant laws and regulations, so as to ensure the scientific validity and ethical acceptability of drug clinical trials.Conclusions:It is of great significance for the high-quality development of IRB to improve its organizational structure, optimize its review mechanism and improve its review efficiency.