The importance analysis method represents a powerful tool for quantifying the impact of input uncertainty on the output uncertainty.When an input variable is described by a specific interval rather than a certain prob...The importance analysis method represents a powerful tool for quantifying the impact of input uncertainty on the output uncertainty.When an input variable is described by a specific interval rather than a certain probability distribution,the interval importance measure of input interval variable can be calculated by the traditional non-probabilistic importance analysis methods.Generally,the non-probabilistic importance analysis methods involve the Monte Carlo simulation(MCS)and the optimization-based methods,which both have high computational cost.In order to overcome this problem,this study proposes an interval important analytical method avoids the time-consuming optimization process.First,the original performance function is decomposed into a combination of a series of one-dimensional subsystems.Next,the interval of each variable is divided into several subintervals,and the response value of each one-dimensional subsystem at a specific input point is calculated.Then,the obtained responses are taken as specific values of the new input variable,and the interval importance is calculated by the approximated performance function.Compared with the traditional non-probabilistic importance analysis method,the proposed method significantly reduces the computational cost caused by the MCS and optimization process.In the proposed method,the number of function evaluations is equal to one plus the sum of the subintervals of all of the variables.The efficiency and accuracy of the proposed method are verified by five examples.The results show that the proposed method is not only efficient but also accurate.展开更多
目的探究间歇无氧运动对正常体重及超重哮喘患儿呼吸功能和运动能力的影响,为制订针对性的运动处方提供依据。方法选取2015年1月至2017年10月于本院就诊的2640例哮喘患儿为研究对象,根据体质指数(body mass index,BMI)将入选患儿分为超...目的探究间歇无氧运动对正常体重及超重哮喘患儿呼吸功能和运动能力的影响,为制订针对性的运动处方提供依据。方法选取2015年1月至2017年10月于本院就诊的2640例哮喘患儿为研究对象,根据体质指数(body mass index,BMI)将入选患儿分为超重组(BMI>24 kg/m^2,1176例)和正常体重组(BMI≤24 kg/m2,1464例),均进行8周间歇无氧运动。比较两组患儿运动前后呼吸功能和运动能力的变化、无氧运动训练情况及不良反应发生情况。结果两组患儿训练完成率及不良反应发生率比较均无显著差异(χ~2=0.346,P=0.852;χ~2=2.711,P=0.100)。与训练前比较,两组患儿训练后呼气流量峰值(peak expiratory flow,PEF),峰值功率、平均功率及疲劳指数(fatigue index,FI)均显著升高(P<0.05),正常体重组患儿PEF和FI均显著高于超重组(P<0.05),用力肺活量(forced vital capacity,FVC)、第一秒用力呼气量(forced expiratory volume in first second,FEV1)及FEV1/FVC训练前后均无显著差异(P>0.05)。结论间歇无氧运动可明显改善哮喘患儿的呼吸功能和运动能力,尤其对正常体重患儿的改善效果更加明显,同时具有较高的安全性。展开更多
目的探讨胎儿超声心动图定量右心时间间期在右心室流出道梗阻性疾病(RVOTO)胎儿右心功能评估中的价值。方法这是一项前瞻性研究。纳入2021年2月至2022年8月在浙江大学医学院附属邵逸夫医院超声心动图诊断为RVOTO的胎儿28例(RVOTO组)及...目的探讨胎儿超声心动图定量右心时间间期在右心室流出道梗阻性疾病(RVOTO)胎儿右心功能评估中的价值。方法这是一项前瞻性研究。纳入2021年2月至2022年8月在浙江大学医学院附属邵逸夫医院超声心动图诊断为RVOTO的胎儿28例(RVOTO组)及同期胎龄匹配的心脏超声检查未见明显异常的胎儿114例(正常组)。胎儿右心功能参数包括M型超声心动图测量三尖瓣环收缩期位移(TAPSE)、组织多普勒(TDI)获取三尖瓣环舒张期流速曲线并测量舒张早期速度(E')及舒张晚期速度(A'),并计算E'/A'值,同时测量右心等容收缩时间(ICT)、等容舒张时间(IRT)、充盈时间(FT)、射血时间(ET)及心动周期(CT),并通过公式计算胎儿右心的心肌做功指数(RVMPI)、收缩舒张时间指数(SDI)、收缩舒张持续时间比(SDR)、充盈时间分数(FTF)和射血时间分数(ETF)。比较2组间各超声心动图参数,分析其差异性。结果RVOTO组IRT平均值为(43.21±4.88)ms,低于正常组(45.71±5.12)ms;RVOTO组ICT平均值为(42.79±5.59)ms,低于正常组(47.82±7.09)ms;RVOTO组胎儿(ICT+IRT)平均值为(87.29±7.78)ms,低于正常组(93.51±10.48)ms;RVOTO组FT平均值为(124.46±4.70)ms,低于正常组(142.00±15.77)ms,以上参数2组间比较差异均有统计学意义(P均<0.05)。RVOTO组胎儿RVMPI指数大于正常组(0.52±0.06 vs 0.48±0.07,P<0.001),RVOTO组SDI大于正常组(2.17±0.18 vs 1.95±0.24,P<0.001),RVOTO组SDR大于正常组(1.35±0.12 vs 1.22±0.12,P<0.001),RVOTO组FTF小于正常组(0.31±0.02 vs 0.34±0.03,P<0.001),三尖瓣环E'值正常组大于RVOTO组(6.38±1.82 vs 5.59±1.96,P<0.001),三尖瓣环E'/A'值正常组大于RVOTO组(0.62±0.11 vs 0.51±0.12,P<0.001)。结论胎儿超声心动图定量右心室MPI、SDI、SDR、FTF及三尖瓣环E'值和E'/A'比值有助于对RVOTO胎儿的右心功能进行综合评价,对评估胎儿当前疾病状态及估测预后有潜在的临床应用价值。展开更多
文摘The importance analysis method represents a powerful tool for quantifying the impact of input uncertainty on the output uncertainty.When an input variable is described by a specific interval rather than a certain probability distribution,the interval importance measure of input interval variable can be calculated by the traditional non-probabilistic importance analysis methods.Generally,the non-probabilistic importance analysis methods involve the Monte Carlo simulation(MCS)and the optimization-based methods,which both have high computational cost.In order to overcome this problem,this study proposes an interval important analytical method avoids the time-consuming optimization process.First,the original performance function is decomposed into a combination of a series of one-dimensional subsystems.Next,the interval of each variable is divided into several subintervals,and the response value of each one-dimensional subsystem at a specific input point is calculated.Then,the obtained responses are taken as specific values of the new input variable,and the interval importance is calculated by the approximated performance function.Compared with the traditional non-probabilistic importance analysis method,the proposed method significantly reduces the computational cost caused by the MCS and optimization process.In the proposed method,the number of function evaluations is equal to one plus the sum of the subintervals of all of the variables.The efficiency and accuracy of the proposed method are verified by five examples.The results show that the proposed method is not only efficient but also accurate.
文摘目的探究间歇无氧运动对正常体重及超重哮喘患儿呼吸功能和运动能力的影响,为制订针对性的运动处方提供依据。方法选取2015年1月至2017年10月于本院就诊的2640例哮喘患儿为研究对象,根据体质指数(body mass index,BMI)将入选患儿分为超重组(BMI>24 kg/m^2,1176例)和正常体重组(BMI≤24 kg/m2,1464例),均进行8周间歇无氧运动。比较两组患儿运动前后呼吸功能和运动能力的变化、无氧运动训练情况及不良反应发生情况。结果两组患儿训练完成率及不良反应发生率比较均无显著差异(χ~2=0.346,P=0.852;χ~2=2.711,P=0.100)。与训练前比较,两组患儿训练后呼气流量峰值(peak expiratory flow,PEF),峰值功率、平均功率及疲劳指数(fatigue index,FI)均显著升高(P<0.05),正常体重组患儿PEF和FI均显著高于超重组(P<0.05),用力肺活量(forced vital capacity,FVC)、第一秒用力呼气量(forced expiratory volume in first second,FEV1)及FEV1/FVC训练前后均无显著差异(P>0.05)。结论间歇无氧运动可明显改善哮喘患儿的呼吸功能和运动能力,尤其对正常体重患儿的改善效果更加明显,同时具有较高的安全性。
文摘目的探讨胎儿超声心动图定量右心时间间期在右心室流出道梗阻性疾病(RVOTO)胎儿右心功能评估中的价值。方法这是一项前瞻性研究。纳入2021年2月至2022年8月在浙江大学医学院附属邵逸夫医院超声心动图诊断为RVOTO的胎儿28例(RVOTO组)及同期胎龄匹配的心脏超声检查未见明显异常的胎儿114例(正常组)。胎儿右心功能参数包括M型超声心动图测量三尖瓣环收缩期位移(TAPSE)、组织多普勒(TDI)获取三尖瓣环舒张期流速曲线并测量舒张早期速度(E')及舒张晚期速度(A'),并计算E'/A'值,同时测量右心等容收缩时间(ICT)、等容舒张时间(IRT)、充盈时间(FT)、射血时间(ET)及心动周期(CT),并通过公式计算胎儿右心的心肌做功指数(RVMPI)、收缩舒张时间指数(SDI)、收缩舒张持续时间比(SDR)、充盈时间分数(FTF)和射血时间分数(ETF)。比较2组间各超声心动图参数,分析其差异性。结果RVOTO组IRT平均值为(43.21±4.88)ms,低于正常组(45.71±5.12)ms;RVOTO组ICT平均值为(42.79±5.59)ms,低于正常组(47.82±7.09)ms;RVOTO组胎儿(ICT+IRT)平均值为(87.29±7.78)ms,低于正常组(93.51±10.48)ms;RVOTO组FT平均值为(124.46±4.70)ms,低于正常组(142.00±15.77)ms,以上参数2组间比较差异均有统计学意义(P均<0.05)。RVOTO组胎儿RVMPI指数大于正常组(0.52±0.06 vs 0.48±0.07,P<0.001),RVOTO组SDI大于正常组(2.17±0.18 vs 1.95±0.24,P<0.001),RVOTO组SDR大于正常组(1.35±0.12 vs 1.22±0.12,P<0.001),RVOTO组FTF小于正常组(0.31±0.02 vs 0.34±0.03,P<0.001),三尖瓣环E'值正常组大于RVOTO组(6.38±1.82 vs 5.59±1.96,P<0.001),三尖瓣环E'/A'值正常组大于RVOTO组(0.62±0.11 vs 0.51±0.12,P<0.001)。结论胎儿超声心动图定量右心室MPI、SDI、SDR、FTF及三尖瓣环E'值和E'/A'比值有助于对RVOTO胎儿的右心功能进行综合评价,对评估胎儿当前疾病状态及估测预后有潜在的临床应用价值。
