In this article, a partially linear single-index model /or longitudinal data is investigated. The generalized penalized spline least squares estimates of the unknown parameters are suggested. All parameters can be est...In this article, a partially linear single-index model /or longitudinal data is investigated. The generalized penalized spline least squares estimates of the unknown parameters are suggested. All parameters can be estimated simultaneously by the proposed method while the feature of longitudinal data is considered. The existence, strong consistency and asymptotic normality of the estimators are proved under suitable conditions. A simulation study is conducted to investigate the finite sample performance of the proposed method. Our approach can also be used to study the pure single-index model for longitudinal data.展开更多
In this paper, we consider the variable selection for the parametric components of varying coefficient partially linear models with censored data. By constructing a penalized auxiliary vector ingeniously, we propose a...In this paper, we consider the variable selection for the parametric components of varying coefficient partially linear models with censored data. By constructing a penalized auxiliary vector ingeniously, we propose an empirical likelihood based variable selection procedure, and show that it is consistent and satisfies the sparsity. The simulation studies show that the proposed variable selection method is workable.展开更多
This paper considers the local linear regression estimators for partially linear model with censored data. Which have some nice large-sample behaviors and are easy to implement. By many simulation runs, the author als...This paper considers the local linear regression estimators for partially linear model with censored data. Which have some nice large-sample behaviors and are easy to implement. By many simulation runs, the author also found that the estimators show remarkable in the small sample case yet.展开更多
Under Type-Ⅱ progressively hybrid censoring, this paper discusses statistical inference and optimal design on stepstress partially accelerated life test for hybrid system in presence of masked data. It is assumed tha...Under Type-Ⅱ progressively hybrid censoring, this paper discusses statistical inference and optimal design on stepstress partially accelerated life test for hybrid system in presence of masked data. It is assumed that the lifetime of the component in hybrid systems follows independent and identical modified Weibull distributions. The maximum likelihood estimations(MLEs)of the unknown parameters, acceleration factor and reliability indexes are derived by using the Newton-Raphson algorithm. The asymptotic variance-covariance matrix and the approximate confidence intervals are obtained based on normal approximation to the asymptotic distribution of MLEs of model parameters. Moreover,two bootstrap confidence intervals are constructed by using the parametric bootstrap method. The optimal time of changing stress levels is determined under D-optimality and A-optimality criteria.Finally, the Monte Carlo simulation study is carried out to illustrate the proposed procedures.展开更多
In this paper, we discuss some characteristic properties of partial abstract data type (PADT) and show the diffrence between PADT and abstract data type (ADT) in specification of programming language. Finally, we clar...In this paper, we discuss some characteristic properties of partial abstract data type (PADT) and show the diffrence between PADT and abstract data type (ADT) in specification of programming language. Finally, we clarify that PADT is necessary in programming language description.展开更多
电池充电时的初始荷电状态SOC(state of charge)往往是随机的,因此在实际应用中难以得到锂电池完整的充电数据,针对这一问题提出一种基于部分充电数据的锂电池健康状态SOH(state of health)估计方法。通过建立的门控循环单元-反向传播GR...电池充电时的初始荷电状态SOC(state of charge)往往是随机的,因此在实际应用中难以得到锂电池完整的充电数据,针对这一问题提出一种基于部分充电数据的锂电池健康状态SOH(state of health)估计方法。通过建立的门控循环单元-反向传播GRU-BP(gated recurrent unit-back propagation)模型,可以由部分充电数据得到完整的充电曲线,然后在完整的充电曲线中提取能够有效表征电池老化程度的特征进行SOH预测。该方法能够实现在恒流充电模式下的任意定长电压区间充电数据下电池的SOH估计。通过实验证明,所提出的模型在数据不完备的情况下能够有效预测锂电池SOH,其估计的均方根误差RMSE(root mean square error)均在2%以下。展开更多
局部放电是表征电力设备绝缘劣化的关键早期征兆之一,但其在现场实际发生的概率较低,且不同放电类型的发生频率存在显著差异,导致可用于智能诊断的训练样本存在严重的类别不平衡。为此,提出一种面向样本不平衡的局部放电缺陷识别方法,...局部放电是表征电力设备绝缘劣化的关键早期征兆之一,但其在现场实际发生的概率较低,且不同放电类型的发生频率存在显著差异,导致可用于智能诊断的训练样本存在严重的类别不平衡。为此,提出一种面向样本不平衡的局部放电缺陷识别方法,融合加权软动态时间规整重心平均(Dynamic Time Warping Barycenter Averaging,DBA)数据增强与DenseNet分类模型。首先,利用加权软DBA算法对训练集中的少数类样本进行扩充,以重构更均衡的数据分布;然而,采用增强后的数据训练DenseNet网络,实现端到端的故障识别。实验表明,采用所提方法对少数类扩充1000个样本后,模型整体准确率提升至88.5%,在保持多数类高识别率的同时,显著改善了少数类别的检测性能,为复杂现场条件下的设备状态评估提供了可靠依据。展开更多
电池健康状态SOH(state of health)评估在确保储能系统安全稳定运行方面具有重要意义。然而,使用固定电压段作为模型输入的方法在实际应用中受到用户使用习惯变化的限制,且多数利用容量增量IC(incremental capacity)分析估计SOH的研究...电池健康状态SOH(state of health)评估在确保储能系统安全稳定运行方面具有重要意义。然而,使用固定电压段作为模型输入的方法在实际应用中受到用户使用习惯变化的限制,且多数利用容量增量IC(incremental capacity)分析估计SOH的研究仍存在着平滑参数选择较为困难的问题。提出的滑动窗口平滑方法在获得平滑IC曲线的同时,简化了实际应用中参数的选择过程。该方法使用了2种互补的Wasserstein距离计算方法评估目标IC曲线和参考曲线的差异,并将该差异作为健康特征HF(health feature)与对应电压段起始电压结合,作为模型输入,用于训练高斯过程回归模型。测试结果显示,任意区间的电压段,即使是未包含IC曲线峰值的部分充电数据,均可作为模型输入来获得低于2%均方根误差RMSE(root mean square error)的SOH估算结果。此外,分析了不同平滑参数、采样频率及估计模型对估算结果的影响。分析结果表明,所提取的HFs具有较强的鲁棒性,模型具有较高的估计精度。展开更多
A balancing method was used to build a DC partial discharge (PD) testing circuit for electrical equipment,and a narrow-band detection system was designed using detection resistance and a filter. After signal accesse...A balancing method was used to build a DC partial discharge (PD) testing circuit for electrical equipment,and a narrow-band detection system was designed using detection resistance and a filter. After signal accessed a high-speed digital acquisition (DAQ) card,the system was triggered to extract a single partial discharge (PD) signal. To eliminate the interference pulses caused by power supply ripple,etc.,the time domain and frequency domain features of pulses were extracted. Based on the features,cluster analysis was used to exclude interference pulses. Two-dimensional and three-dimensional histograms were obtained by use of the Δt method. Then,22 discharge statistical operators were calculated for the two-dimensional charts. Lastly,the defective capacitors were tested to verify the system's ability. The results show that the system is capable of PD detection in electrical equipment.展开更多
基金Supported by the National Natural Science Foundation of China (10571008)the Natural Science Foundation of Henan (092300410149)the Core Teacher Foundationof Henan (2006141)
摘要In this article, a partially linear single-index model /or longitudinal data is investigated. The generalized penalized spline least squares estimates of the unknown parameters are suggested. All parameters can be estimated simultaneously by the proposed method while the feature of longitudinal data is considered. The existence, strong consistency and asymptotic normality of the estimators are proved under suitable conditions. A simulation study is conducted to investigate the finite sample performance of the proposed method. Our approach can also be used to study the pure single-index model for longitudinal data.
基金Supported by the National Natural Science Foundation of China(Grant Nos.1110111911126332)+2 种基金the National Social Science Foundation of China(Grant No.11CTJ004)the Natural Science Foundation of Guangxi Province(Grant No.2010GXNSFB013051)the Philosophy and Social Sciences Foundation of Guangxi Province(Grant No.11FTJ002)
摘要In this paper, we consider the variable selection for the parametric components of varying coefficient partially linear models with censored data. By constructing a penalized auxiliary vector ingeniously, we propose an empirical likelihood based variable selection procedure, and show that it is consistent and satisfies the sparsity. The simulation studies show that the proposed variable selection method is workable.
摘要This paper considers the local linear regression estimators for partially linear model with censored data. Which have some nice large-sample behaviors and are easy to implement. By many simulation runs, the author also found that the estimators show remarkable in the small sample case yet.
基金supported by the National Natural Science Foundation of China(71401134 71571144+1 种基金 71171164)the Program of International Cooperation and Exchanges in Science and Technology Funded by Shaanxi Province(2016KW-033)
摘要Under Type-Ⅱ progressively hybrid censoring, this paper discusses statistical inference and optimal design on stepstress partially accelerated life test for hybrid system in presence of masked data. It is assumed that the lifetime of the component in hybrid systems follows independent and identical modified Weibull distributions. The maximum likelihood estimations(MLEs)of the unknown parameters, acceleration factor and reliability indexes are derived by using the Newton-Raphson algorithm. The asymptotic variance-covariance matrix and the approximate confidence intervals are obtained based on normal approximation to the asymptotic distribution of MLEs of model parameters. Moreover,two bootstrap confidence intervals are constructed by using the parametric bootstrap method. The optimal time of changing stress levels is determined under D-optimality and A-optimality criteria.Finally, the Monte Carlo simulation study is carried out to illustrate the proposed procedures.
基金The Project Supported by National Natural Science Foundation of China
摘要In this paper, we discuss some characteristic properties of partial abstract data type (PADT) and show the diffrence between PADT and abstract data type (ADT) in specification of programming language. Finally, we clarify that PADT is necessary in programming language description.
摘要电池充电时的初始荷电状态SOC(state of charge)往往是随机的,因此在实际应用中难以得到锂电池完整的充电数据,针对这一问题提出一种基于部分充电数据的锂电池健康状态SOH(state of health)估计方法。通过建立的门控循环单元-反向传播GRU-BP(gated recurrent unit-back propagation)模型,可以由部分充电数据得到完整的充电曲线,然后在完整的充电曲线中提取能够有效表征电池老化程度的特征进行SOH预测。该方法能够实现在恒流充电模式下的任意定长电压区间充电数据下电池的SOH估计。通过实验证明,所提出的模型在数据不完备的情况下能够有效预测锂电池SOH,其估计的均方根误差RMSE(root mean square error)均在2%以下。
摘要局部放电是表征电力设备绝缘劣化的关键早期征兆之一,但其在现场实际发生的概率较低,且不同放电类型的发生频率存在显著差异,导致可用于智能诊断的训练样本存在严重的类别不平衡。为此,提出一种面向样本不平衡的局部放电缺陷识别方法,融合加权软动态时间规整重心平均(Dynamic Time Warping Barycenter Averaging,DBA)数据增强与DenseNet分类模型。首先,利用加权软DBA算法对训练集中的少数类样本进行扩充,以重构更均衡的数据分布;然而,采用增强后的数据训练DenseNet网络,实现端到端的故障识别。实验表明,采用所提方法对少数类扩充1000个样本后,模型整体准确率提升至88.5%,在保持多数类高识别率的同时,显著改善了少数类别的检测性能,为复杂现场条件下的设备状态评估提供了可靠依据。
摘要电池健康状态SOH(state of health)评估在确保储能系统安全稳定运行方面具有重要意义。然而,使用固定电压段作为模型输入的方法在实际应用中受到用户使用习惯变化的限制,且多数利用容量增量IC(incremental capacity)分析估计SOH的研究仍存在着平滑参数选择较为困难的问题。提出的滑动窗口平滑方法在获得平滑IC曲线的同时,简化了实际应用中参数的选择过程。该方法使用了2种互补的Wasserstein距离计算方法评估目标IC曲线和参考曲线的差异,并将该差异作为健康特征HF(health feature)与对应电压段起始电压结合,作为模型输入,用于训练高斯过程回归模型。测试结果显示,任意区间的电压段,即使是未包含IC曲线峰值的部分充电数据,均可作为模型输入来获得低于2%均方根误差RMSE(root mean square error)的SOH估算结果。此外,分析了不同平滑参数、采样频率及估计模型对估算结果的影响。分析结果表明,所提取的HFs具有较强的鲁棒性,模型具有较高的估计精度。
摘要A balancing method was used to build a DC partial discharge (PD) testing circuit for electrical equipment,and a narrow-band detection system was designed using detection resistance and a filter. After signal accessed a high-speed digital acquisition (DAQ) card,the system was triggered to extract a single partial discharge (PD) signal. To eliminate the interference pulses caused by power supply ripple,etc.,the time domain and frequency domain features of pulses were extracted. Based on the features,cluster analysis was used to exclude interference pulses. Two-dimensional and three-dimensional histograms were obtained by use of the Δt method. Then,22 discharge statistical operators were calculated for the two-dimensional charts. Lastly,the defective capacitors were tested to verify the system's ability. The results show that the system is capable of PD detection in electrical equipment.