Critical aortic valve stenosis in newborns is the cause of a severe clinical condition with the onset of symptoms during first hours after birth.We present a clinical case of a successful surgical correction of a crit...Critical aortic valve stenosis in newborns is the cause of a severe clinical condition with the onset of symptoms during first hours after birth.We present a clinical case of a successful surgical correction of a critical aortic stenosis using a hybrid method applied in a newborn during the first day of life.The infant was diagnosed with a hypoplastic left heart complex with an intact atrial septum(aortic and mitral valves stenosis variant),that led to the cardiogenic shock and acute pulmonary edema.The procedure included bilateral banding of the pulmonary artery branches and atrioseptostomy with stenting of the interatrial septum.The surgery was performed through a median sternotomy.展开更多
为解决通道不一致性对传统极化敏感阵列长矢量模型的测向精度影响及传统长矢量多重信号分类(multiple signal classification,MUSIC)算法实时性不高的问题,本文在传统极化敏感测向系统基础上,在阵列中心增加一个标量平面螺旋天线,利用...为解决通道不一致性对传统极化敏感阵列长矢量模型的测向精度影响及传统长矢量多重信号分类(multiple signal classification,MUSIC)算法实时性不高的问题,本文在传统极化敏感测向系统基础上,在阵列中心增加一个标量平面螺旋天线,利用其天线方向图的增益稳定性,作为内部源对其他矢量通道不一致性进行实时校正;然后将结合标量圆阵和快速傅里叶变换(fastFouriertransform,FFT)的快速MUSIC算法推广到矢量阵列,提出降维快速极化MUSIC算法.仿真结果验证了此误差校正方法的有效性,且快速算法在保证测角精度前提下有效提高了算法实时性.本文为极化敏感阵列测向提供了一种误差校正方法及一种快速实用的测向算法.展开更多
Wind energy is the burgeoning renewable energy. Accurate wind speed prediction is necessary to ensure the stability and reliability of the power grid for wind energy. This study focuses on developing a novel hybrid fo...Wind energy is the burgeoning renewable energy. Accurate wind speed prediction is necessary to ensure the stability and reliability of the power grid for wind energy. This study focuses on developing a novel hybrid forecasting model to tackle adverse effects caused by strong variability and abrupt changes in wind speed. The hybrid model combines data decomposition and error correction strategy for a wind speed forecasting model applied to wind energy. First, wavelet packet decomposition is applied to wind speed series to obtain stationary subseries. Next, outlier robust extreme learning machine is implemented to predict subseries. Finally, an error correction strategy coupled with data decomposition is designed to repair preliminary prediction results. In addition, four measured datasets from China and USAwind farms with different time intervals are used to evaluate the performance of the proposed approach. Experimental analysis indicates that the proposed model outperforms the compared models. Results show that(1) the prediction accuracy of the proposed model is remarkably improved compared with other conventional models;(2) the proposed model can reduce the influence of the end effect in the decomposition-based forecasting model;(3) the coupling framework is successful for enhancing performance of hybrid forecasting model.展开更多
针对目前带探头补偿的平面近远场变换中,探头H面方向图对远区副瓣引入较大误差的情况,结合国内传统的E面电场法和K.T.Selvan提出的边缘电流逼近法各自的优点,利用混合算法研究了一种新的探头方向图逼近公式,并将其应用于平面近场测试中...针对目前带探头补偿的平面近远场变换中,探头H面方向图对远区副瓣引入较大误差的情况,结合国内传统的E面电场法和K.T.Selvan提出的边缘电流逼近法各自的优点,利用混合算法研究了一种新的探头方向图逼近公式,并将其应用于平面近场测试中。通过在某大型微波暗室对一频段阵列天线进行实际测量,分别用E面电场法、边缘电流逼近法以及新的方法进行带探头补偿的近远场变换。最后,将各种方法与实际测试结果进行比较,求得其误差曲线,并在全域的角度分析各种方法的-50 d B超低副瓣精度。结果表明,此方法集合了前两种方法的优点,相比E面电场法,远区副瓣精度提高了8.2 d B,整个角域内副瓣精度提高了1.13 d B;相比边缘电流逼近法,近区副瓣精度提高了0.89d B,整个角域内副瓣精度提高了0.87d B。展开更多
文摘Critical aortic valve stenosis in newborns is the cause of a severe clinical condition with the onset of symptoms during first hours after birth.We present a clinical case of a successful surgical correction of a critical aortic stenosis using a hybrid method applied in a newborn during the first day of life.The infant was diagnosed with a hypoplastic left heart complex with an intact atrial septum(aortic and mitral valves stenosis variant),that led to the cardiogenic shock and acute pulmonary edema.The procedure included bilateral banding of the pulmonary artery branches and atrioseptostomy with stenting of the interatrial septum.The surgery was performed through a median sternotomy.
文摘为解决通道不一致性对传统极化敏感阵列长矢量模型的测向精度影响及传统长矢量多重信号分类(multiple signal classification,MUSIC)算法实时性不高的问题,本文在传统极化敏感测向系统基础上,在阵列中心增加一个标量平面螺旋天线,利用其天线方向图的增益稳定性,作为内部源对其他矢量通道不一致性进行实时校正;然后将结合标量圆阵和快速傅里叶变换(fastFouriertransform,FFT)的快速MUSIC算法推广到矢量阵列,提出降维快速极化MUSIC算法.仿真结果验证了此误差校正方法的有效性,且快速算法在保证测角精度前提下有效提高了算法实时性.本文为极化敏感阵列测向提供了一种误差校正方法及一种快速实用的测向算法.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11732010, 12072185, 11972220, 11825204, and 92052201)
文摘Wind energy is the burgeoning renewable energy. Accurate wind speed prediction is necessary to ensure the stability and reliability of the power grid for wind energy. This study focuses on developing a novel hybrid forecasting model to tackle adverse effects caused by strong variability and abrupt changes in wind speed. The hybrid model combines data decomposition and error correction strategy for a wind speed forecasting model applied to wind energy. First, wavelet packet decomposition is applied to wind speed series to obtain stationary subseries. Next, outlier robust extreme learning machine is implemented to predict subseries. Finally, an error correction strategy coupled with data decomposition is designed to repair preliminary prediction results. In addition, four measured datasets from China and USAwind farms with different time intervals are used to evaluate the performance of the proposed approach. Experimental analysis indicates that the proposed model outperforms the compared models. Results show that(1) the prediction accuracy of the proposed model is remarkably improved compared with other conventional models;(2) the proposed model can reduce the influence of the end effect in the decomposition-based forecasting model;(3) the coupling framework is successful for enhancing performance of hybrid forecasting model.
文摘针对目前带探头补偿的平面近远场变换中,探头H面方向图对远区副瓣引入较大误差的情况,结合国内传统的E面电场法和K.T.Selvan提出的边缘电流逼近法各自的优点,利用混合算法研究了一种新的探头方向图逼近公式,并将其应用于平面近场测试中。通过在某大型微波暗室对一频段阵列天线进行实际测量,分别用E面电场法、边缘电流逼近法以及新的方法进行带探头补偿的近远场变换。最后,将各种方法与实际测试结果进行比较,求得其误差曲线,并在全域的角度分析各种方法的-50 d B超低副瓣精度。结果表明,此方法集合了前两种方法的优点,相比E面电场法,远区副瓣精度提高了8.2 d B,整个角域内副瓣精度提高了1.13 d B;相比边缘电流逼近法,近区副瓣精度提高了0.89d B,整个角域内副瓣精度提高了0.87d B。
