为了能够更加准确地评价语音包丢失对基于IP的语音传输(voice over internet protocol,Vo IP)的语音质量的损伤,对ITU-T G.107建议书提出的语音质量预测模型E-Model中计算丢包与编码造成的损伤Ie-eff的方法作出改进,在综合考虑语音包的...为了能够更加准确地评价语音包丢失对基于IP的语音传输(voice over internet protocol,Vo IP)的语音质量的损伤,对ITU-T G.107建议书提出的语音质量预测模型E-Model中计算丢包与编码造成的损伤Ie-eff的方法作出改进,在综合考虑语音包的内部特性和存在突发连续丢包情况后,提出利用在固定语音长度下,语音实际损失时间Tloss来衡量语音包丢失造成的语音损伤。仿真结果表明,相比原有模型,改进后的模型得到的语音质量评分同主观语音质量评估方法(perceptual evaluation of speech quality,PESQ)评分相比,皮尔森相关系数平均提高了0.045 8,均方根误差平均降低了0.053 4,改进后的E-Model模型在评价语音质量时与PESQ更具有一致性,可以更为准确地预测Vo IP通信的语音质量。展开更多
The coupled CFD-E-model for multiphase micro-mixing was developed,and used to predict the micro-mixing effects on the parallel competing chemical reactions in semi-batch gas–liquid and solid–liquid stirred tanks.Bas...The coupled CFD-E-model for multiphase micro-mixing was developed,and used to predict the micro-mixing effects on the parallel competing chemical reactions in semi-batch gas–liquid and solid–liquid stirred tanks.Based on the multiphase macro-flow field,the key parameters of the micro-mixing E-model were obtained with solving the Reynolds-averaged transport equations of mixture fraction and its variance at low computational costs.Compared with experimental data,the multiphase numerical method shows the satisfactory predicting ability.For the gas–liquid system,the segregated reaction zone is mainly near the feed point,and shrinks to the exit of feed-pipe when the feed position is closer to the impeller.Besides,surface feed requires more time to completely exhaust the added H+solution than that of impeller region feed at the same operating condition.For the solid–liquid system,when the solid suspension cloud is formed at high solid holdups,the flow velocity in the clear liquid layer above the cloud is notably reduced and the reactions proceed slowly in this almost stagnant zone.Therefore,the segregation index in this case is larger than that in the dilute solid–liquid system.展开更多
目的探索适合我国食管癌患者的疾病诊断相关分组(diagnosis related groups,DRGs)方案,为响应国家DRGs/按病种分值付费(diagnosis-intervention packet,DIP)付费改革政策、规范医保精准支付、优化专科运营与质控管理提供实践依据。方法...目的探索适合我国食管癌患者的疾病诊断相关分组(diagnosis related groups,DRGs)方案,为响应国家DRGs/按病种分值付费(diagnosis-intervention packet,DIP)付费改革政策、规范医保精准支付、优化专科运营与质控管理提供实践依据。方法收集某三甲医院2021—2025年上半年收治的食管癌患者的病案首页数据,采用单因素分析和多元线性回归模型筛选影响住院费用的关键因素,进而运用E-CHAID决策树算法构建DRGs分组方案。结果手术/操作类型、住院天数、是否进行达芬奇手术和是否使用呼吸机4个分类节点将1995例患者划分为6个DRGs分组,组间差异有统计学意义(H=1641.395,P<0.001),组内变异系数(CV)为0.12~0.61,组内同质性良好;全组超限病例72例(3.61%),处于合理区间。结论基于E-CHAID算法构建的食管癌患者住院费用分组方案合理。该模型证实手术方式、创新技术应用以及病情危重程度是影响住院费用的核心因素,为实现食管癌住院费用的精细化管理与DRGs付费改革提供参考。展开更多
分布式光伏(distributed photovoltaic,DPV)的大规模无序接入为山区配电网带来了过电压、功率倒送等问题,影响配电网的稳定运行。如何准确计算山区配电网DPV承载能力已成为目前亟待研究和解决的重要问题。针对这一问题,以山区配电网所...分布式光伏(distributed photovoltaic,DPV)的大规模无序接入为山区配电网带来了过电压、功率倒送等问题,影响配电网的稳定运行。如何准确计算山区配电网DPV承载能力已成为目前亟待研究和解决的重要问题。针对这一问题,以山区配电网所能接入的DPV最大容量为目标函数,构建考虑储能系统(energy storage system,ESS)容量健康退化和含有ESS的智能软开关(soft open point integrated with energy storage,E-SOP)的确定性模型。其次,分析DPV出力曲线,并在确定性模型的基础上构建山区柔性配电网DPV承载能力双层鲁棒模型。然后,根据KKT条件将模型转化为混合整数线性规划问题,并采用Gurobi求解器求得模型评估结果。最后,通过改进的IEEE33节点山区柔性配电网进行算例分析,研究ESS容量健康退化和DPV出力不确定性对DPV承载能力的影响。算例分析表明所提模型使DPV承载能力提高了8.43%,验证了该模型的可行性和有效性。展开更多
文摘为了能够更加准确地评价语音包丢失对基于IP的语音传输(voice over internet protocol,Vo IP)的语音质量的损伤,对ITU-T G.107建议书提出的语音质量预测模型E-Model中计算丢包与编码造成的损伤Ie-eff的方法作出改进,在综合考虑语音包的内部特性和存在突发连续丢包情况后,提出利用在固定语音长度下,语音实际损失时间Tloss来衡量语音包丢失造成的语音损伤。仿真结果表明,相比原有模型,改进后的模型得到的语音质量评分同主观语音质量评估方法(perceptual evaluation of speech quality,PESQ)评分相比,皮尔森相关系数平均提高了0.045 8,均方根误差平均降低了0.053 4,改进后的E-Model模型在评价语音质量时与PESQ更具有一致性,可以更为准确地预测Vo IP通信的语音质量。
基金supported by the National Key Research and Development Program(2016YFB0301702)the National Natural Science Foundation of China(21808221,21776282,21938009)+3 种基金Major Research Plan of NSFC(91934301)the Key Research Program of Frontier Sciences,CAS(QYZDJ-SSW-JSC030)the Key Research Program of Nanjing IPE Institute of Green Manufacturing Industry(No.E0010719)the Youth Innovation Promotion Association CAS。
文摘The coupled CFD-E-model for multiphase micro-mixing was developed,and used to predict the micro-mixing effects on the parallel competing chemical reactions in semi-batch gas–liquid and solid–liquid stirred tanks.Based on the multiphase macro-flow field,the key parameters of the micro-mixing E-model were obtained with solving the Reynolds-averaged transport equations of mixture fraction and its variance at low computational costs.Compared with experimental data,the multiphase numerical method shows the satisfactory predicting ability.For the gas–liquid system,the segregated reaction zone is mainly near the feed point,and shrinks to the exit of feed-pipe when the feed position is closer to the impeller.Besides,surface feed requires more time to completely exhaust the added H+solution than that of impeller region feed at the same operating condition.For the solid–liquid system,when the solid suspension cloud is formed at high solid holdups,the flow velocity in the clear liquid layer above the cloud is notably reduced and the reactions proceed slowly in this almost stagnant zone.Therefore,the segregation index in this case is larger than that in the dilute solid–liquid system.
文摘目的探索适合我国食管癌患者的疾病诊断相关分组(diagnosis related groups,DRGs)方案,为响应国家DRGs/按病种分值付费(diagnosis-intervention packet,DIP)付费改革政策、规范医保精准支付、优化专科运营与质控管理提供实践依据。方法收集某三甲医院2021—2025年上半年收治的食管癌患者的病案首页数据,采用单因素分析和多元线性回归模型筛选影响住院费用的关键因素,进而运用E-CHAID决策树算法构建DRGs分组方案。结果手术/操作类型、住院天数、是否进行达芬奇手术和是否使用呼吸机4个分类节点将1995例患者划分为6个DRGs分组,组间差异有统计学意义(H=1641.395,P<0.001),组内变异系数(CV)为0.12~0.61,组内同质性良好;全组超限病例72例(3.61%),处于合理区间。结论基于E-CHAID算法构建的食管癌患者住院费用分组方案合理。该模型证实手术方式、创新技术应用以及病情危重程度是影响住院费用的核心因素,为实现食管癌住院费用的精细化管理与DRGs付费改革提供参考。
文摘分布式光伏(distributed photovoltaic,DPV)的大规模无序接入为山区配电网带来了过电压、功率倒送等问题,影响配电网的稳定运行。如何准确计算山区配电网DPV承载能力已成为目前亟待研究和解决的重要问题。针对这一问题,以山区配电网所能接入的DPV最大容量为目标函数,构建考虑储能系统(energy storage system,ESS)容量健康退化和含有ESS的智能软开关(soft open point integrated with energy storage,E-SOP)的确定性模型。其次,分析DPV出力曲线,并在确定性模型的基础上构建山区柔性配电网DPV承载能力双层鲁棒模型。然后,根据KKT条件将模型转化为混合整数线性规划问题,并采用Gurobi求解器求得模型评估结果。最后,通过改进的IEEE33节点山区柔性配电网进行算例分析,研究ESS容量健康退化和DPV出力不确定性对DPV承载能力的影响。算例分析表明所提模型使DPV承载能力提高了8.43%,验证了该模型的可行性和有效性。
