The purpose of this paper is to broaden the knowledge of mean difference and, in particular, of an important distribution model known as truncated normal distribution, which is widely used in applied sciences and econ...The purpose of this paper is to broaden the knowledge of mean difference and, in particular, of an important distribution model known as truncated normal distribution, which is widely used in applied sciences and economics. In this work, we obtained the general formula of mean difference, which is not yet reported in literature, for the aforementioned distribution model and also for particular truncated cases.展开更多
The purpose of this paper is to broaden the knowledge of mean difference and,<span><span><span style="font-family:;" "=""> </span></span></span><span sty...The purpose of this paper is to broaden the knowledge of mean difference and,<span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">in particular, of an important distribution model known as Tukey lambda, which is generally used to choose a model to fit data.</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">We have obtained compact formulas, which are not yet reported in literature, of mean deviation and mean difference related to the said distribution model.</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">These results made it possible to analyze the relationships among variability indexes, namely standard deviation, mean deviation and mean difference, regarding Tukey lambda model.</span></span></span>展开更多
目的观察俯卧位应用不同呼气末正压条件下对每搏量变异度、脉搏压变异度及脉搏灌注变异指数预测容量状态的准确性及诊断阈值的影响。方法选择在全麻下俯卧位行颈椎或腰椎手术患者60例,全麻后连续监测每搏量变异度(SVV)、脉搏压变异度(P...目的观察俯卧位应用不同呼气末正压条件下对每搏量变异度、脉搏压变异度及脉搏灌注变异指数预测容量状态的准确性及诊断阈值的影响。方法选择在全麻下俯卧位行颈椎或腰椎手术患者60例,全麻后连续监测每搏量变异度(SVV)、脉搏压变异度(PPV)、脉搏灌注变异指数(PVI)等血流动力学指标,在俯卧位体位下分别加以0、5、10、15 mm Hg的呼气末正压(PEEP),记录每个PEEP时点的各血流动力学指标数值,后以7 ml/kg进行补液试验后,再分别加以0、5、10、15 mm Hg的PEEP值后记录输液后各血流动力学指标数值。然后以输液前后每搏量变异指数的差值(ΔSVI)将患者分为两组,即有反应组(ΔSVI≥15%)和无反应组(ΔSVI<15%)组,分别绘制SVV、PPV和PVI判断扩容效应的受试者工作特征性(ROC)曲线,确定俯卧位时在不同PEEP条件下对SVV、PPV和PVI预测容量状况的准确性、诊断阈值及其相关性。结果与平卧位相比较,俯卧位条件下SVV、PPV、PVI均增大(P<0.05),平均动脉压降低(P<0.05),心率、每搏量、每搏量指数、心输出量、心指数差异无统计学意义(P>0.05)。俯卧位时,在PEEP=0、5、10、15 mm Hg条件下,SVV判断扩容有效的ROC曲线下面积分别为0.864、0.759、0.718、0.521,PPV判断扩容有效的ROC曲线下面积分别为0.873、0.792、0.705、0.505,PVI判断扩容有效的ROC曲线下面积分别为0.851、0.765、0.709、0.512。当PEEP=0 mm Hg时,SVV、PPV、PVI诊断阈值分别为10.5、11.5、13.5;当PEEP=5 mm Hg时,SVV、PPV、PVI诊断阈值分别为11.5、13.5、14.5;当PEEP=10 mm Hg时,SVV、PPV、PVI诊断阈值分别为13.5、14.5、16.5。俯卧位时在不同PEEP条件下SVV、PPV、PVI变化分别与PEEP值变化呈正相关(r分别为0.424、0.561、0.553,P<0.01)。结论 SVV、PPV和PVI在PEEP≤10 mm Hg时可以准确预测俯卧位时应用全麻机械通气患者的容量状况,三者预测容量状况的准确性相似,诊断阈值随PEEP值增大而增�展开更多
文摘The purpose of this paper is to broaden the knowledge of mean difference and, in particular, of an important distribution model known as truncated normal distribution, which is widely used in applied sciences and economics. In this work, we obtained the general formula of mean difference, which is not yet reported in literature, for the aforementioned distribution model and also for particular truncated cases.
文摘The purpose of this paper is to broaden the knowledge of mean difference and,<span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">in particular, of an important distribution model known as Tukey lambda, which is generally used to choose a model to fit data.</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">We have obtained compact formulas, which are not yet reported in literature, of mean deviation and mean difference related to the said distribution model.</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">These results made it possible to analyze the relationships among variability indexes, namely standard deviation, mean deviation and mean difference, regarding Tukey lambda model.</span></span></span>
文摘目的观察俯卧位应用不同呼气末正压条件下对每搏量变异度、脉搏压变异度及脉搏灌注变异指数预测容量状态的准确性及诊断阈值的影响。方法选择在全麻下俯卧位行颈椎或腰椎手术患者60例,全麻后连续监测每搏量变异度(SVV)、脉搏压变异度(PPV)、脉搏灌注变异指数(PVI)等血流动力学指标,在俯卧位体位下分别加以0、5、10、15 mm Hg的呼气末正压(PEEP),记录每个PEEP时点的各血流动力学指标数值,后以7 ml/kg进行补液试验后,再分别加以0、5、10、15 mm Hg的PEEP值后记录输液后各血流动力学指标数值。然后以输液前后每搏量变异指数的差值(ΔSVI)将患者分为两组,即有反应组(ΔSVI≥15%)和无反应组(ΔSVI<15%)组,分别绘制SVV、PPV和PVI判断扩容效应的受试者工作特征性(ROC)曲线,确定俯卧位时在不同PEEP条件下对SVV、PPV和PVI预测容量状况的准确性、诊断阈值及其相关性。结果与平卧位相比较,俯卧位条件下SVV、PPV、PVI均增大(P<0.05),平均动脉压降低(P<0.05),心率、每搏量、每搏量指数、心输出量、心指数差异无统计学意义(P>0.05)。俯卧位时,在PEEP=0、5、10、15 mm Hg条件下,SVV判断扩容有效的ROC曲线下面积分别为0.864、0.759、0.718、0.521,PPV判断扩容有效的ROC曲线下面积分别为0.873、0.792、0.705、0.505,PVI判断扩容有效的ROC曲线下面积分别为0.851、0.765、0.709、0.512。当PEEP=0 mm Hg时,SVV、PPV、PVI诊断阈值分别为10.5、11.5、13.5;当PEEP=5 mm Hg时,SVV、PPV、PVI诊断阈值分别为11.5、13.5、14.5;当PEEP=10 mm Hg时,SVV、PPV、PVI诊断阈值分别为13.5、14.5、16.5。俯卧位时在不同PEEP条件下SVV、PPV、PVI变化分别与PEEP值变化呈正相关(r分别为0.424、0.561、0.553,P<0.01)。结论 SVV、PPV和PVI在PEEP≤10 mm Hg时可以准确预测俯卧位时应用全麻机械通气患者的容量状况,三者预测容量状况的准确性相似,诊断阈值随PEEP值增大而增�
