A Receiver Operating Characteristic(ROC)analysis of a power is important and useful in clinical trials.A Classical Conditional Power(CCP)is a probability of a classical rejection region given values of true treatment ...A Receiver Operating Characteristic(ROC)analysis of a power is important and useful in clinical trials.A Classical Conditional Power(CCP)is a probability of a classical rejection region given values of true treatment effect and interim result.For hypotheses and reversed hypotheses under normal models,we obtain analytical expressions of the ROC curves of the CCP,find optimal ROC curves of the CCP,investigate the superiority of the ROC curves of the CCP,calculate critical values of the False Positive Rate(FPR),True Positive Rate(TPR),and cutoff of the optimal CCP,and give go/no go decisions at the interim of the optimal CCP.In addition,extensive numerical experiments are carried out to exemplify our theoretical results.Finally,a real data example is performed to illustrate the go/no go decisions of the optimal CCP.展开更多
本文使用中国家庭动态跟踪调查(CFPS)数据,基于代理工具测试模型(Proxy means testing,PMT)并结合ROC曲线方法(Receiver Operating Characteristics)研究低保的反贫困瞄准问题.结果显示:城市单个贫困指数以卫生间类型、电脑拥有情况来...本文使用中国家庭动态跟踪调查(CFPS)数据,基于代理工具测试模型(Proxy means testing,PMT)并结合ROC曲线方法(Receiver Operating Characteristics)研究低保的反贫困瞄准问题.结果显示:城市单个贫困指数以卫生间类型、电脑拥有情况来衡量较为有效,农村单个贫困指数则以户主年龄、冰箱拥有情况来衡量较为有效.更改贫困概率门槛值会影响公共预算转移支付贫困瞄准结果,对于一个较低的贫困概率门槛值,其对应的覆盖率(公共预算转移支付覆盖贫困人口)和漏损率(非贫困人口被纳入公共预算转移支付)都比较高.当政策制定者把对覆盖贫困人口和排除非贫困人口的目标赋予同等权重时,城乡贫困概率门槛值约为0.5左右.当贫困率较低且使用与贫困率相同的瞄准率时,基于PMT模型的贫困瞄准较差.在贫困率给定的条件下,随着受益比率(包含率)的增加,贫困瞄准的精确性在提高.使用全覆盖所需预算的百分比下降时,覆盖率和漏损率也都呈现下降态势,贫困率逐渐上升,预算中做覆盖之用的比例上升,而预算中漏损部分的比例下降.贫困线的变动会影响覆盖率、漏损率.展开更多
基金supported by the National Social Science Fund of China(Grand No.21XTJ001).
文摘A Receiver Operating Characteristic(ROC)analysis of a power is important and useful in clinical trials.A Classical Conditional Power(CCP)is a probability of a classical rejection region given values of true treatment effect and interim result.For hypotheses and reversed hypotheses under normal models,we obtain analytical expressions of the ROC curves of the CCP,find optimal ROC curves of the CCP,investigate the superiority of the ROC curves of the CCP,calculate critical values of the False Positive Rate(FPR),True Positive Rate(TPR),and cutoff of the optimal CCP,and give go/no go decisions at the interim of the optimal CCP.In addition,extensive numerical experiments are carried out to exemplify our theoretical results.Finally,a real data example is performed to illustrate the go/no go decisions of the optimal CCP.
文摘滑坡地质灾害易发性评价是防灾减灾的一种重要手段,易发性评价模型的选取和优化至关重要。以思南县为研究区,选取高程、坡度、曲率、地层、土地利用、年平均降雨量等16个评价因子,采用频率比(frequency ratio,FR)模型与支持向量机(support vector machine,SVM)模型和随机森林(random forest,RF)模型相耦合,引入网格搜索方法来获取SVM模型、RF模型及其耦合模型最优参数组合并用于模型训练,最终构建SVM、RF、FR-SVM及FR-RF模型对整个研究区进行滑坡易发性预测,并进行了受试者操作特征(receiver operating characteristics,ROC)曲线验证。结果表明:与单一机器学习模型相比,耦合机器学习有更多的滑坡灾害样本落于高易发区和极高易发区,有更高的准确率。单一模型中,RF模型有较多的滑坡灾害样本落于高易发区和极高易发区,耦合模型中,FR-RF模型有较多的滑坡灾害样本落于高易发区和极高易发区,且FR模型和FR-RF模型中没有滑坡灾害样本落在极低易发区,表明无论是单一模型还是耦合模型,RF模型的性能优于SVM模型。4种模型的ROC预测曲线的曲线下面积(area under the curve,AUC)分别为0.8316、0.8439、0.8644、0.9104,说明FR模型与RF模型结合的耦合模型有更高的准确率,该模型更适用于思南县的滑坡易发性评价研究,评价结果可为当地滑坡地质灾害的防灾减灾提供一定的参考。
文摘本文使用中国家庭动态跟踪调查(CFPS)数据,基于代理工具测试模型(Proxy means testing,PMT)并结合ROC曲线方法(Receiver Operating Characteristics)研究低保的反贫困瞄准问题.结果显示:城市单个贫困指数以卫生间类型、电脑拥有情况来衡量较为有效,农村单个贫困指数则以户主年龄、冰箱拥有情况来衡量较为有效.更改贫困概率门槛值会影响公共预算转移支付贫困瞄准结果,对于一个较低的贫困概率门槛值,其对应的覆盖率(公共预算转移支付覆盖贫困人口)和漏损率(非贫困人口被纳入公共预算转移支付)都比较高.当政策制定者把对覆盖贫困人口和排除非贫困人口的目标赋予同等权重时,城乡贫困概率门槛值约为0.5左右.当贫困率较低且使用与贫困率相同的瞄准率时,基于PMT模型的贫困瞄准较差.在贫困率给定的条件下,随着受益比率(包含率)的增加,贫困瞄准的精确性在提高.使用全覆盖所需预算的百分比下降时,覆盖率和漏损率也都呈现下降态势,贫困率逐渐上升,预算中做覆盖之用的比例上升,而预算中漏损部分的比例下降.贫困线的变动会影响覆盖率、漏损率.
