ABSTRACT
In order to improve the measuring accuracy of the Hemispherical Resonator Gyro under variable temperature, aiming at the problem of "external temperature is unavailable and internal temperature is unmeasurable," a multiple regression based method is proposed for compensating temperature error in the gyro. The relationship between the internal temperature and the resonant frequency of the gyro is analyzed theoretically. According to a constant temperature experiment, a linear relationship between them is derived based on the least square method. The analysis of a temperature-rising experiment shows that the correlation of the gyro output with the internal temperature is much higher than that with the external temperature. Therefore, taking the resonant frequency as an independent variable, a multiple regression model is established for compensating the temperature error. The compensation effect of the model is verified by temperature-rising and temperature-dropping experiments, which show that the output sequence before compensation is not stable, while it is stable after compensation. After compensation, the drift of the gyro decreases by 62.76% and 48.48%, respectively, and its measuring accuracy becomes equivalent to that at the constant temperature. The experimental results verify the feasibility and effectiveness of the model developed for indirect compensation of temperature error.
ABSTRACT
OBJECTIVE: To study the effect of atorvastatin on atherosclerotic rabbits. METHODS: A total of 60 New Zealand male rabbits were randomly divided into the normal group, model group and atorvastatin group. The replication rabbit atherosclerotic model with immune injury combined with a high fat diet feeding was used. All rabbits were sacrificed after 3 months. TLR4 and NF-κB p65 were observed by HE staining, immunohistochemistry and western blotting. RESULTS: The expression of TLR4, NF-κB p65 were significantly increased in the model group compared with the normal group. The expression of TLR4 and NF-κB p65 decreased significantly in the atorvastatin group, and there was no difference compared with the normal group. CONCLUSIONS: The effect of atorvastatin on atherosclerosis may be achieved by the inhibition of the expression of TLR4 and NF-κB p65.
