Introduction-Being an easy-to-use (eight items) quality of life questionnaire specific to GERD, the Reflux- Qual Short form (RQS ) was developed for use in everyday practice. The purpose of this study was to assess ...Introduction-Being an easy-to-use (eight items) quality of life questionnaire specific to GERD, the Reflux- Qual Short form (RQS ) was developed for use in everyday practice. The purpose of this study was to assess the psychometric properties of the RQS . Methods and materials -The reliability of the RQS-was measured by the Cronbachs alpha coefficient and its clinical validity by comparing the RQS score for increasing clinical severity groups. The RQS discriminative power was compared with that of the SF- 12. Sensitivity to change over time was measured by calculating effect- sizes. Results-The reliability and validity of the questionnaire were assessed on a sample of 1195 patients. Its psychometric properties were very satisfactory: Cronbach alpha = 0.84;RQS score significantly reduced for the worst- affected patients; the discriminative power was up to 5 times higher when compared with the SF- 12. Sensitivity to change over time, evaluated with 362 patients, showed highly significant differences between groups with different levels of clinical progression (P = 0.0001). Conclusion- The RQS is a quality of life measurement instrument specific to GERD which is short, reliable, valid, and sensitive to within and between- subject differences.展开更多
The high-speed development of space defense technology demands a high state estimation capacity for spacecraft tracking methods.However,reentry flight is accompanied by complex flight environments,which brings to the ...The high-speed development of space defense technology demands a high state estimation capacity for spacecraft tracking methods.However,reentry flight is accompanied by complex flight environments,which brings to the uncertain,complex,and strongly coupled non-Gaussian detection noise.As a result,there are several intractable considerations on the problem of state estimation tasks corrupted by complex non-Gaussian outliers for non-linear dynamics systems in practical application.To address these issues,a new iterated rational quadratic(RQ)kernel high-order unscented Kalman filtering(IRQHUKF)algorithm via capturing the statistics to break through the limitations of the Gaussian assumption is proposed.Firstly,the characteristic analysis of the RQ kernel is investigated in detail,which is the first attempt to carry out an exploration of the heavy-tailed characteristic and the ability on capturing highorder moments of the RQ kernel.Subsequently,the RQ kernel method is first introduced into the UKF algorithm as an error optimization criterion,termed the iterated RQ kernel-UKF(RQ-UKF)algorithm by derived analytically,which not only retains the high-order moments propagation process but also enhances the approximation capacity in the non-Gaussian noise problem for its ability in capturing highorder moments and heavy-tailed characteristics.Meanwhile,to tackle the limitations of the Gaussian distribution assumption in the linearization process of the non-linear systems,the high-order Sigma Points(SP)as a subsidiary role in propagating the state high-order statistics is devised by the moments matching method to improve the RQ-UKF.Finally,to further improve the flexibility of the IRQ-HUKF algorithm in practical application,an adaptive kernel parameter is derived analytically grounded in the Kullback-Leibler divergence(KLD)method and parametric sensitivity analysis of the RQ kernel.The simulation results demonstrate that the novel IRQ-HUKF algorithm is more robust and outperforms the existing advanced UKF with respect to the kernel method in reentry vehicle tracking scenarios under various noise environments.展开更多
文摘Introduction-Being an easy-to-use (eight items) quality of life questionnaire specific to GERD, the Reflux- Qual Short form (RQS ) was developed for use in everyday practice. The purpose of this study was to assess the psychometric properties of the RQS . Methods and materials -The reliability of the RQS-was measured by the Cronbachs alpha coefficient and its clinical validity by comparing the RQS score for increasing clinical severity groups. The RQS discriminative power was compared with that of the SF- 12. Sensitivity to change over time was measured by calculating effect- sizes. Results-The reliability and validity of the questionnaire were assessed on a sample of 1195 patients. Its psychometric properties were very satisfactory: Cronbach alpha = 0.84;RQS score significantly reduced for the worst- affected patients; the discriminative power was up to 5 times higher when compared with the SF- 12. Sensitivity to change over time, evaluated with 362 patients, showed highly significant differences between groups with different levels of clinical progression (P = 0.0001). Conclusion- The RQS is a quality of life measurement instrument specific to GERD which is short, reliable, valid, and sensitive to within and between- subject differences.
基金supported by the National Natural Science Foundation of China under Grant No.12072090.
文摘The high-speed development of space defense technology demands a high state estimation capacity for spacecraft tracking methods.However,reentry flight is accompanied by complex flight environments,which brings to the uncertain,complex,and strongly coupled non-Gaussian detection noise.As a result,there are several intractable considerations on the problem of state estimation tasks corrupted by complex non-Gaussian outliers for non-linear dynamics systems in practical application.To address these issues,a new iterated rational quadratic(RQ)kernel high-order unscented Kalman filtering(IRQHUKF)algorithm via capturing the statistics to break through the limitations of the Gaussian assumption is proposed.Firstly,the characteristic analysis of the RQ kernel is investigated in detail,which is the first attempt to carry out an exploration of the heavy-tailed characteristic and the ability on capturing highorder moments of the RQ kernel.Subsequently,the RQ kernel method is first introduced into the UKF algorithm as an error optimization criterion,termed the iterated RQ kernel-UKF(RQ-UKF)algorithm by derived analytically,which not only retains the high-order moments propagation process but also enhances the approximation capacity in the non-Gaussian noise problem for its ability in capturing highorder moments and heavy-tailed characteristics.Meanwhile,to tackle the limitations of the Gaussian distribution assumption in the linearization process of the non-linear systems,the high-order Sigma Points(SP)as a subsidiary role in propagating the state high-order statistics is devised by the moments matching method to improve the RQ-UKF.Finally,to further improve the flexibility of the IRQ-HUKF algorithm in practical application,an adaptive kernel parameter is derived analytically grounded in the Kullback-Leibler divergence(KLD)method and parametric sensitivity analysis of the RQ kernel.The simulation results demonstrate that the novel IRQ-HUKF algorithm is more robust and outperforms the existing advanced UKF with respect to the kernel method in reentry vehicle tracking scenarios under various noise environments.
