A selective moving window partial least squares(SMW-PLS) soft sensor was proposed in this paper and applied to a hydro-isomerization process for on-line estimation of para-xylene(PX) content. Aiming at the high freque...A selective moving window partial least squares(SMW-PLS) soft sensor was proposed in this paper and applied to a hydro-isomerization process for on-line estimation of para-xylene(PX) content. Aiming at the high frequency of model updating in previous recursive PLS methods, a selective updating strategy was developed. The model adaptation is activated once the prediction error is larger than a preset threshold, or the model is kept unchanged.As a result, the frequency of model updating is reduced greatly, while the change of prediction accuracy is minor.The performance of the proposed model is better as compared with that of other PLS-based model. The compromise between prediction accuracy and real-time performance can be obtained by regulating the threshold. The guidelines to determine the model parameters are illustrated. In summary, the proposed SMW-PLS method can deal with the slow time-varying processes effectively.展开更多
In this paper, by using the Nevanlinna Theory on angular domain, we establish a theorem which concerns the growth of entire function and his zero. As an application, we survey the location of zero of higher order diff...In this paper, by using the Nevanlinna Theory on angular domain, we establish a theorem which concerns the growth of entire function and his zero. As an application, we survey the location of zero of higher order differential equation, which can be regarded as an alternating but precise version of Wu and Yi.展开更多
A cogeneration plant can run at off-design due to change of load demand or ambient conditions. The cogeneration considered for this study is gas turbine based engine consists of variable stator vanes （VSVs） compress...A cogeneration plant can run at off-design due to change of load demand or ambient conditions. The cogeneration considered for this study is gas turbine based engine consists of variable stator vanes （VSVs） compressor that are re-staggered for loads greater than 50% to maintain the gas turbine exhaust gas temperature at the set value. In order to evaluate the exergetic performance of the cogeneration, exergy model of each cogeneration component is formulated. A 4.2 MW gas turbine based cogeneration plant is analysed for a wide range of part load operations including the effect of VSVs modulation. For loads less than 50%, the major exergy destruction contributors are the combustor and the loss with the stack gas. At full load, the exergy destructions in the combustor, turbine, heat recovery, compressor and the exergy loss with stack gas are 63.7, 14.1, 11.5, 5.7, and 4.9%, respectively. The corresponding first and second law cogeneration efficiencies are 78.5 and 45%, respectively. For comparison purpose both the first and second law efticiencies of each component are represented together. This analysis would help to identify the equipment where the potential for performance improvement is high, and trends which may aid in the design of future plants.展开更多
Objective： To observe the clinical effect of electroacupuncture in treating perimenopause syndrome （PMS） and explore its possible action mechanism. Methods： All of 110 cases with PMS were randomized into group A [...Objective： To observe the clinical effect of electroacupuncture in treating perimenopause syndrome （PMS） and explore its possible action mechanism. Methods： All of 110 cases with PMS were randomized into group A [Guanyuan （CV 4） and Sanyinjiao （SP 6）] and group B [Neiguan （PC 6） and Zusanli （ST 36）], 55 cases in each. After 4-week treatments, the Kupperman Menopausal Index （KMI） was adopted to evaluate the therapeutic effect. Estradiol （E2）, follicle-stimulating hormone （FSH） and luteinizing hormone （LH） were assayed respectively before and after treatments. Results： The KMI decreased by 52.6% in group A, versus 47.4% in group B. The total effective rate was 93.6% in group A, versus 85.7% in group B, and the difference was not significant （P〈0.05）. The content of E2 both increased in the two groups after 4-week treatments （P〈0.05）; the contents of FSH and LH dropped but without statistical difference （P〈0.05）. Conclusion： Both of the two acupoints groups can significantly lower KMI, and effectively increase the contents of E2 in patients with PMS展开更多
基金Supported by the National Natural Science Foundation of China(61203133,61203072)the Open Project Program of the State Key Laboratory of Industrial Control Technology(ICT1214)
文摘A selective moving window partial least squares(SMW-PLS) soft sensor was proposed in this paper and applied to a hydro-isomerization process for on-line estimation of para-xylene(PX) content. Aiming at the high frequency of model updating in previous recursive PLS methods, a selective updating strategy was developed. The model adaptation is activated once the prediction error is larger than a preset threshold, or the model is kept unchanged.As a result, the frequency of model updating is reduced greatly, while the change of prediction accuracy is minor.The performance of the proposed model is better as compared with that of other PLS-based model. The compromise between prediction accuracy and real-time performance can be obtained by regulating the threshold. The guidelines to determine the model parameters are illustrated. In summary, the proposed SMW-PLS method can deal with the slow time-varying processes effectively.
文摘In this paper, by using the Nevanlinna Theory on angular domain, we establish a theorem which concerns the growth of entire function and his zero. As an application, we survey the location of zero of higher order differential equation, which can be regarded as an alternating but precise version of Wu and Yi.
文摘A cogeneration plant can run at off-design due to change of load demand or ambient conditions. The cogeneration considered for this study is gas turbine based engine consists of variable stator vanes （VSVs） compressor that are re-staggered for loads greater than 50% to maintain the gas turbine exhaust gas temperature at the set value. In order to evaluate the exergetic performance of the cogeneration, exergy model of each cogeneration component is formulated. A 4.2 MW gas turbine based cogeneration plant is analysed for a wide range of part load operations including the effect of VSVs modulation. For loads less than 50%, the major exergy destruction contributors are the combustor and the loss with the stack gas. At full load, the exergy destructions in the combustor, turbine, heat recovery, compressor and the exergy loss with stack gas are 63.7, 14.1, 11.5, 5.7, and 4.9%, respectively. The corresponding first and second law cogeneration efficiencies are 78.5 and 45%, respectively. For comparison purpose both the first and second law efticiencies of each component are represented together. This analysis would help to identify the equipment where the potential for performance improvement is high, and trends which may aid in the design of future plants.
文摘Objective： To observe the clinical effect of electroacupuncture in treating perimenopause syndrome （PMS） and explore its possible action mechanism. Methods： All of 110 cases with PMS were randomized into group A [Guanyuan （CV 4） and Sanyinjiao （SP 6）] and group B [Neiguan （PC 6） and Zusanli （ST 36）], 55 cases in each. After 4-week treatments, the Kupperman Menopausal Index （KMI） was adopted to evaluate the therapeutic effect. Estradiol （E2）, follicle-stimulating hormone （FSH） and luteinizing hormone （LH） were assayed respectively before and after treatments. Results： The KMI decreased by 52.6% in group A, versus 47.4% in group B. The total effective rate was 93.6% in group A, versus 85.7% in group B, and the difference was not significant （P〈0.05）. The content of E2 both increased in the two groups after 4-week treatments （P〈0.05）; the contents of FSH and LH dropped but without statistical difference （P〈0.05）. Conclusion： Both of the two acupoints groups can significantly lower KMI, and effectively increase the contents of E2 in patients with PMS
