The small sample prediction problem which commonly exists in reliability analysis was discussed with the progressive prediction method in this paper.The modeling and estimation procedure,as well as the forecast and co...The small sample prediction problem which commonly exists in reliability analysis was discussed with the progressive prediction method in this paper.The modeling and estimation procedure,as well as the forecast and confidence limits formula of the progressive auto regressive(PAR) method were discussed in great detail.PAR model not only inherits the simple linear features of auto regressive(AR) model,but also has applicability for nonlinear systems.An application was illustrated for predicting the future fatigue failure for Tantalum electrolytic capacitors.Forecasting results of PAR model were compared with auto regressive moving average(ARMA) model,and it can be seen that the PAR method can be considered good and shows a promise for future applications.展开更多
Objective: Physical loading changes bone microstructure and may influence quantitative ultrasound(QUS) parameters. This study aims at evaluating the effect of physical loading on bone QUS measurement. Methods: Ten fre...Objective: Physical loading changes bone microstructure and may influence quantitative ultrasound(QUS) parameters. This study aims at evaluating the effect of physical loading on bone QUS measurement. Methods: Ten fresh bovine bone specimens were studied, which were scanned by a micro-CT and the density and structure parameters were calculated. The QUS measurement was performed when specimens subjected to loading, which changed from 0 to 1,000 N with the step of 100 N. Statistical analysis was performed to evaluate the difference between n BUA measured with and without loading, and the relationship between n BUA and the parameters measured by micro-CT. Results: While the loading exerted on bone lugher than 200 N, the measured nBUA significantly higher than n BUA measured without loading. With the increasing of loading, which exerted on bone, the values of nBUA also increased. A new parameter, the slope of the linearity fitted curve of nBUA values measured under different loading conditions, was introduced to evaluate BMD. The correlation coefficient between the slope and BMD is-0.869(P=0.001). Conclusion: Physical loading substantially influences bone QUS measurement. QUS measurement performed under loading condition may be a new ultrasound method for osteoporosis diagnosis.展开更多
基金Supported by Fanzhou Science and Research Foundation for Young Scholars(Grant No.20100511)
文摘The small sample prediction problem which commonly exists in reliability analysis was discussed with the progressive prediction method in this paper.The modeling and estimation procedure,as well as the forecast and confidence limits formula of the progressive auto regressive(PAR) method were discussed in great detail.PAR model not only inherits the simple linear features of auto regressive(AR) model,but also has applicability for nonlinear systems.An application was illustrated for predicting the future fatigue failure for Tantalum electrolytic capacitors.Forecasting results of PAR model were compared with auto regressive moving average(ARMA) model,and it can be seen that the PAR method can be considered good and shows a promise for future applications.
文摘Objective: Physical loading changes bone microstructure and may influence quantitative ultrasound(QUS) parameters. This study aims at evaluating the effect of physical loading on bone QUS measurement. Methods: Ten fresh bovine bone specimens were studied, which were scanned by a micro-CT and the density and structure parameters were calculated. The QUS measurement was performed when specimens subjected to loading, which changed from 0 to 1,000 N with the step of 100 N. Statistical analysis was performed to evaluate the difference between n BUA measured with and without loading, and the relationship between n BUA and the parameters measured by micro-CT. Results: While the loading exerted on bone lugher than 200 N, the measured nBUA significantly higher than n BUA measured without loading. With the increasing of loading, which exerted on bone, the values of nBUA also increased. A new parameter, the slope of the linearity fitted curve of nBUA values measured under different loading conditions, was introduced to evaluate BMD. The correlation coefficient between the slope and BMD is-0.869(P=0.001). Conclusion: Physical loading substantially influences bone QUS measurement. QUS measurement performed under loading condition may be a new ultrasound method for osteoporosis diagnosis.
