Generation of the second harmonic initiated by Bell-Plesset effects in a cylindrical geometry is studied analytically. For an initial single-mode velocity perturSation, the second-order mode-coupling formula is obtain...Generation of the second harmonic initiated by Bell-Plesset effects in a cylindrical geometry is studied analytically. For an initial single-mode velocity perturSation, the second-order mode-coupling formula is obtained by expanding the perturbation displacement and velocity potential up to the second-order accuracy. It is found that the initially symmetric interface evolves into a significant bubble-spike asymmetric pattern. The second-order solutions clearly show that the amplitude of the spike grows faster than that of the buSble. The temporal evolutions of the amplitudes of the 5ubSie and spike are dependent on the interface velocity Vo. The larger interface velocity leads to the smaller amplitude of the perturbation at an arbitrary interface position in a cylindrically convergent geometry.展开更多
目的应用贝叶斯Logistic回归分析法探讨糖尿病患者血糖稳定性存在错误分类时的影响因素,并与传统Logistic回归分析法相比较,为临床工作者提供一种结局指标存在错误分类时的研究方法。方法采用分层抽样的方法选取江苏省糖尿病并发症监测...目的应用贝叶斯Logistic回归分析法探讨糖尿病患者血糖稳定性存在错误分类时的影响因素,并与传统Logistic回归分析法相比较,为临床工作者提供一种结局指标存在错误分类时的研究方法。方法采用分层抽样的方法选取江苏省糖尿病并发症监测点上的患者,以糖化血红蛋白(glycosylated hemoglobin,HbA1c)为“金标准”给出问卷调查血糖稳定性的灵敏度与特异度的专家先验,应用贝叶斯方法和传统方法进行单因素与多因素分析,回归模型的选择以偏差信息准则(deviance information criterion,DIC)或赤池信息准则(Akaike information criterion,AIC)小且参数最少为标准。结果调查对象共509人,年龄为(62.32±9.29)岁,贝叶斯多因素Logistic回归分析得出糖尿病病程短(OR=0.299,95%CI:0.093~0.840)、文化程度高(OR=0.348,95%CI:0.130~0.914)为血糖稳定性的保护因素,食用腌制食物的频率高(OR=4.310,95%CI:1.369~22.131)、BMI异常(OR=2.912,95%CI:1.196~9.865)为血糖稳定性的危险因素。传统Logistic回归分析也得出了同样的结果,但每周食用腌制食物的频率和BMI的OR(95%CI)值被低估,分别为1.671(1.100~2.538)、1.650(1.115~2.440)。结论贝叶斯方法和传统Logistic回归分析法均得出病程、文化程度、食用腌制食物的频率以及BMI是影响血糖稳定性的因素,且贝叶斯方法可以校正因变量分类错误,得到的结果更可信。展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 11074300, 11075024, 11274026, and 11275031, the National Basic Research Program of China under Grant Nos 2013CB834100 and 2013CBA01504, and the National Science and Technology Major Project of the Ministry of Science and Technology of China under Grant Nos 2011ZX05038-001.
文摘Generation of the second harmonic initiated by Bell-Plesset effects in a cylindrical geometry is studied analytically. For an initial single-mode velocity perturSation, the second-order mode-coupling formula is obtained by expanding the perturbation displacement and velocity potential up to the second-order accuracy. It is found that the initially symmetric interface evolves into a significant bubble-spike asymmetric pattern. The second-order solutions clearly show that the amplitude of the spike grows faster than that of the buSble. The temporal evolutions of the amplitudes of the 5ubSie and spike are dependent on the interface velocity Vo. The larger interface velocity leads to the smaller amplitude of the perturbation at an arbitrary interface position in a cylindrically convergent geometry.
文摘目的应用贝叶斯Logistic回归分析法探讨糖尿病患者血糖稳定性存在错误分类时的影响因素,并与传统Logistic回归分析法相比较,为临床工作者提供一种结局指标存在错误分类时的研究方法。方法采用分层抽样的方法选取江苏省糖尿病并发症监测点上的患者,以糖化血红蛋白(glycosylated hemoglobin,HbA1c)为“金标准”给出问卷调查血糖稳定性的灵敏度与特异度的专家先验,应用贝叶斯方法和传统方法进行单因素与多因素分析,回归模型的选择以偏差信息准则(deviance information criterion,DIC)或赤池信息准则(Akaike information criterion,AIC)小且参数最少为标准。结果调查对象共509人,年龄为(62.32±9.29)岁,贝叶斯多因素Logistic回归分析得出糖尿病病程短(OR=0.299,95%CI:0.093~0.840)、文化程度高(OR=0.348,95%CI:0.130~0.914)为血糖稳定性的保护因素,食用腌制食物的频率高(OR=4.310,95%CI:1.369~22.131)、BMI异常(OR=2.912,95%CI:1.196~9.865)为血糖稳定性的危险因素。传统Logistic回归分析也得出了同样的结果,但每周食用腌制食物的频率和BMI的OR(95%CI)值被低估,分别为1.671(1.100~2.538)、1.650(1.115~2.440)。结论贝叶斯方法和传统Logistic回归分析法均得出病程、文化程度、食用腌制食物的频率以及BMI是影响血糖稳定性的因素,且贝叶斯方法可以校正因变量分类错误,得到的结果更可信。
