In the paper weakness of air leakage system in our company is discussed firstly. Secondly the improved scheme of air leakage system including auto-control is designed. Then, the tooling with role of location and recov...In the paper weakness of air leakage system in our company is discussed firstly. Secondly the improved scheme of air leakage system including auto-control is designed. Then, the tooling with role of location and recovery is developed. At last the application of design optimization is processed. The result reveals that the system of air leakage detection is very valuable and important to manufacture.展开更多
针对核电多回路耦合系统在升功率运行中异常传感器检测困难、检测延时及检测精度低等问题,提出了一种自联想核回归模型(auto-associative kernel regression,简称AAKR)与修正序贯概率比检验(sequential probability ratio test,简称SPRT...针对核电多回路耦合系统在升功率运行中异常传感器检测困难、检测延时及检测精度低等问题,提出了一种自联想核回归模型(auto-associative kernel regression,简称AAKR)与修正序贯概率比检验(sequential probability ratio test,简称SPRT)相结合的方法。首先,利用小波软阈值降噪方法对监测数据预处理,获取高质量的多源传感器解调信号;其次,采用AAKR构造传感器正常运行数据的估计值,并获取多源传感器测量值与估计值之间的残差;然后,运用滑动时间窗获取不同阶段残差向量的均值和方差,设计一种SPRT检测规则对传感器残差进行异常检测;最后,用核电一、二回路耦合系统模拟机实验数据进行方法验证与性能分析。结果表明,所提传感器异常检测方法的准确率达到99.52%,异常检测延时降低了81.73%,可有效提高现有核电厂传感器异常检测的稳定性。展开更多
Both auto-power spectrum and cross-power spectrum need to be controlled in multi-input multi-output （MIMO） random vibration test. During the control process with the difference control algorithm （DCA）, a lower tri...Both auto-power spectrum and cross-power spectrum need to be controlled in multi-input multi-output （MIMO） random vibration test. During the control process with the difference control algorithm （DCA）, a lower triangular matrix is derived from Cholesky decomposition of a reference spectrum matrix. The diagonal elements of the lower triangular matrix （DELTM） may become negative. These negative values have no meaning in physical significance and can cause divergence of auto-power spectrum control. A proportional root mean square control algorithm （PRMSCA） provides another method to avoid the divergence caused by negative values of DELTM, but PRMSCA cannot control the cross-power spectrum. A new control algorithm named matrix power control algorithm （MPCA） is proposed in the paper. MPCA can guarantee that DELTM is always positive in the auto-power spectrum control. MPCA can also control the cross-power spectrum. After these three control algorithms are analyzed, three-input three-output random vibration control tests are implemented on a three-axis vibration shaker. The results show the validity of the proposed MPCA.展开更多
The expression of an auto-antibody in patients with edematous acute pancreatitis and its possible clinical significance was investiaged. Eighteen cases of acute pancreatitis were chosen as experimental group and 25 su...The expression of an auto-antibody in patients with edematous acute pancreatitis and its possible clinical significance was investiaged. Eighteen cases of acute pancreatitis were chosen as experimental group and 25 subjects served as control group. Venous blood samples were taken in both groups at 4 time points: at the day of admission, the 2nd, 4th and 7th day of hospitalization. By using indirect immuno-fluorescence tests the expression of auto-antibody in the samples was semiquantitatively detected. Other biochemical indexes, such as serum amylase, urine amylase, were determined simultaneously. As well, the clinical signs or symptoms were mornitored. It was found that the expression of the auto-antibody was gradually enhanced with the development of acute pancreatitis. The inceased positive expression of auto-antibody showed a correlationship with the improvement of biochemical indexes (r=0.951) and clinical manifestations (r=0.996). There was significant difference between experimental and control groups (P<0.05). During the recovery period of acute pancreatitis, gradually increased auto-antibody expression was detectable. This antibody is against the interstitial structure of the pancreas.展开更多
Based on the auto- corrclation coefficient model.we gave an expression ofsize deviation of raw silk when testing- length is equal to a fraction for the unitlength,and discussed how the ratio of the size deviatinons by...Based on the auto- corrclation coefficient model.we gave an expression ofsize deviation of raw silk when testing- length is equal to a fraction for the unitlength,and discussed how the ratio of the size deviatinons by different testing-length fluctuates with the pseudo- cycle.Using these results as a basis,weexamined how the size deviation with the continuous property of raw silk sizechanges when changing the testing- length from 450 m to ll2.5m.Then weexamined the problem of quality control of raw silk.展开更多
In this article, we use the unrestricted two-regime autoregressive threshold model to test both nonlinearity and stationarity of China's real exchange rate against its Hong Kong and Macao special administrative re...In this article, we use the unrestricted two-regime autoregressive threshold model to test both nonlinearity and stationarity of China's real exchange rate against its Hong Kong and Macao special administrative regions(SARs). Our main finding is that China's real exchange rate is neither linear nor stationary, indicating that the purchasing power parity does not hold between China Mainland and its two SARs, which implies, to certain extent, the three economies may not meet the condition of constituting an optimal currency area.展开更多
文摘In the paper weakness of air leakage system in our company is discussed firstly. Secondly the improved scheme of air leakage system including auto-control is designed. Then, the tooling with role of location and recovery is developed. At last the application of design optimization is processed. The result reveals that the system of air leakage detection is very valuable and important to manufacture.
文摘针对核电多回路耦合系统在升功率运行中异常传感器检测困难、检测延时及检测精度低等问题,提出了一种自联想核回归模型(auto-associative kernel regression,简称AAKR)与修正序贯概率比检验(sequential probability ratio test,简称SPRT)相结合的方法。首先,利用小波软阈值降噪方法对监测数据预处理,获取高质量的多源传感器解调信号;其次,采用AAKR构造传感器正常运行数据的估计值,并获取多源传感器测量值与估计值之间的残差;然后,运用滑动时间窗获取不同阶段残差向量的均值和方差,设计一种SPRT检测规则对传感器残差进行异常检测;最后,用核电一、二回路耦合系统模拟机实验数据进行方法验证与性能分析。结果表明,所提传感器异常检测方法的准确率达到99.52%,异常检测延时降低了81.73%,可有效提高现有核电厂传感器异常检测的稳定性。
基金National Natural Science Foundation of China （10972104） The Fundamental Research Funds for NUAA（NS2010007）
文摘Both auto-power spectrum and cross-power spectrum need to be controlled in multi-input multi-output （MIMO） random vibration test. During the control process with the difference control algorithm （DCA）, a lower triangular matrix is derived from Cholesky decomposition of a reference spectrum matrix. The diagonal elements of the lower triangular matrix （DELTM） may become negative. These negative values have no meaning in physical significance and can cause divergence of auto-power spectrum control. A proportional root mean square control algorithm （PRMSCA） provides another method to avoid the divergence caused by negative values of DELTM, but PRMSCA cannot control the cross-power spectrum. A new control algorithm named matrix power control algorithm （MPCA） is proposed in the paper. MPCA can guarantee that DELTM is always positive in the auto-power spectrum control. MPCA can also control the cross-power spectrum. After these three control algorithms are analyzed, three-input three-output random vibration control tests are implemented on a three-axis vibration shaker. The results show the validity of the proposed MPCA.
文摘The expression of an auto-antibody in patients with edematous acute pancreatitis and its possible clinical significance was investiaged. Eighteen cases of acute pancreatitis were chosen as experimental group and 25 subjects served as control group. Venous blood samples were taken in both groups at 4 time points: at the day of admission, the 2nd, 4th and 7th day of hospitalization. By using indirect immuno-fluorescence tests the expression of auto-antibody in the samples was semiquantitatively detected. Other biochemical indexes, such as serum amylase, urine amylase, were determined simultaneously. As well, the clinical signs or symptoms were mornitored. It was found that the expression of the auto-antibody was gradually enhanced with the development of acute pancreatitis. The inceased positive expression of auto-antibody showed a correlationship with the improvement of biochemical indexes (r=0.951) and clinical manifestations (r=0.996). There was significant difference between experimental and control groups (P<0.05). During the recovery period of acute pancreatitis, gradually increased auto-antibody expression was detectable. This antibody is against the interstitial structure of the pancreas.
文摘Based on the auto- corrclation coefficient model.we gave an expression ofsize deviation of raw silk when testing- length is equal to a fraction for the unitlength,and discussed how the ratio of the size deviatinons by different testing-length fluctuates with the pseudo- cycle.Using these results as a basis,weexamined how the size deviation with the continuous property of raw silk sizechanges when changing the testing- length from 450 m to ll2.5m.Then weexamined the problem of quality control of raw silk.
基金the National Natural Science Foundation of China(No.71373219)
文摘In this article, we use the unrestricted two-regime autoregressive threshold model to test both nonlinearity and stationarity of China's real exchange rate against its Hong Kong and Macao special administrative regions(SARs). Our main finding is that China's real exchange rate is neither linear nor stationary, indicating that the purchasing power parity does not hold between China Mainland and its two SARs, which implies, to certain extent, the three economies may not meet the condition of constituting an optimal currency area.
