针对人工耳蜗在噪声环境下言语感知效果差,以及现有算法降噪能力不足的问题,本研究提出了一种改进的Wave-U-Net模型。通过采取轻量化卷积,引入注意力机制,改进损失函数,优化数据集结构,以提高人工耳蜗的降噪效果。使用短时客观可懂度(sh...针对人工耳蜗在噪声环境下言语感知效果差,以及现有算法降噪能力不足的问题,本研究提出了一种改进的Wave-U-Net模型。通过采取轻量化卷积,引入注意力机制,改进损失函数,优化数据集结构,以提高人工耳蜗的降噪效果。使用短时客观可懂度(short-time objective intelligibility,STOI)、语音质量评估(perceptual evaluation of speech quality,PESQ)、浮点运算次数(floating point operations per second,FLOPs)和参数量(Params)对模型的降噪效果和复杂度进行了评估,分别达到0.81、2.75,0.83 G,1.04 M。实验结果表明,本研究算法在符合人工耳蜗产品规范的基础上,实现了明显的降噪效果,提高了人工耳蜗使用者在复杂噪声环境中的语音感知效果。本研究方法为人工耳蜗算法的改进提供了新的可能,可为听力受损患者提供更好的听觉感受。展开更多
In this study, the physics-based device simulation tool Silvaco ATLAS is used to characterize the electrical properties of an AlGaN/GaN high electron mobility transistor （HEMT） with a U-type gate foot. The U-gate Al...In this study, the physics-based device simulation tool Silvaco ATLAS is used to characterize the electrical properties of an AlGaN/GaN high electron mobility transistor （HEMT） with a U-type gate foot. The U-gate AlGaN/GaN HEMT mainly features a gradually changed sidewall angle, which effectively mitigates the electric field in the channel, thus obtaining enhanced off-state breakdown characteristics. At the same time, only a small additional gate capacitance and decreased gate resistance ensure excellent RF characteristics for the U-gate device. U-gate AlGaN/GaN HEMTs are feasible through adjusting the etching conditions of an inductively coupled plasma system, without introducing any extra process steps. The simulation results are confirmed by experimental measurements. These features indicate that U-gate A1GaN/GaN HEMTs might be promising candidates for use in millimeter-wave power applications.展开更多
U-wave changes during treadmill exercise test were compared between 34 patientswith CAD and 33 normal controls.All of them were confirmed by coronary angiographv.Tenpatients with CAD and 1 normal subject in this study...U-wave changes during treadmill exercise test were compared between 34 patientswith CAD and 33 normal controls.All of them were confirmed by coronary angiographv.Tenpatients with CAD and 1 normal subject in this study showed U-wave inversion during exercisetest.Of the 10 patients,4 had significant stenosis in one-vessel and 6 in multi-vessel of the ma-jor coronary arteries.The sensitivity,specificity and predictive value of exercise-inducedU-wave inversion were 29％, 97％ and 91％,respectively.It is proposed that exercise inducedU-wave inversion is a reliable predictive index of CAD.展开更多
When ocean waves propagate over the sea floor,dynamic wave pressures and bottom shear stresses exert on the surface of seabed.The bottom shear stresses provide a horizontal loading in the wave-seabed interaction syste...When ocean waves propagate over the sea floor,dynamic wave pressures and bottom shear stresses exert on the surface of seabed.The bottom shear stresses provide a horizontal loading in the wave-seabed interaction system,while dynamic wave pressures provide a vertical loading in the system.However,the bottom shear stresses have been ignored in most previous studies in the past.In this study,the effects of the bottom shear stresses on the dynamic response in a seabed of finite thickness under wave loading will be examined,based on Biot＇s dynamic poro-elastic theory.In the model,an ＂u-p＂ approximation will be adopted instead of quasi-static model that have been used in most previous studies.Numerical results indicate that the bottom shear stresses has certain influences on the wave-induced seabed dynamic response.Furthermore,wave and soil characteristics have considerable influences on the relative difference of seabed response between the previous model（without shear stresses） and the present model（with shear stresses）.As shown in the parametric study,the relative differences between two models could up to 10% of p0,depending on the amplitude of bottom shear stresses.展开更多
文摘针对人工耳蜗在噪声环境下言语感知效果差,以及现有算法降噪能力不足的问题,本研究提出了一种改进的Wave-U-Net模型。通过采取轻量化卷积,引入注意力机制,改进损失函数,优化数据集结构,以提高人工耳蜗的降噪效果。使用短时客观可懂度(short-time objective intelligibility,STOI)、语音质量评估(perceptual evaluation of speech quality,PESQ)、浮点运算次数(floating point operations per second,FLOPs)和参数量(Params)对模型的降噪效果和复杂度进行了评估,分别达到0.81、2.75,0.83 G,1.04 M。实验结果表明,本研究算法在符合人工耳蜗产品规范的基础上,实现了明显的降噪效果,提高了人工耳蜗使用者在复杂噪声环境中的语音感知效果。本研究方法为人工耳蜗算法的改进提供了新的可能,可为听力受损患者提供更好的听觉感受。
基金Project supported by the Major Program of the National Natural Science Foundation of China （Grant No. 60890191） and the National Key Basic Research Program of China （Grant No. 2010CB327503）.
文摘In this study, the physics-based device simulation tool Silvaco ATLAS is used to characterize the electrical properties of an AlGaN/GaN high electron mobility transistor （HEMT） with a U-type gate foot. The U-gate AlGaN/GaN HEMT mainly features a gradually changed sidewall angle, which effectively mitigates the electric field in the channel, thus obtaining enhanced off-state breakdown characteristics. At the same time, only a small additional gate capacitance and decreased gate resistance ensure excellent RF characteristics for the U-gate device. U-gate AlGaN/GaN HEMTs are feasible through adjusting the etching conditions of an inductively coupled plasma system, without introducing any extra process steps. The simulation results are confirmed by experimental measurements. These features indicate that U-gate A1GaN/GaN HEMTs might be promising candidates for use in millimeter-wave power applications.
文摘U-wave changes during treadmill exercise test were compared between 34 patientswith CAD and 33 normal controls.All of them were confirmed by coronary angiographv.Tenpatients with CAD and 1 normal subject in this study showed U-wave inversion during exercisetest.Of the 10 patients,4 had significant stenosis in one-vessel and 6 in multi-vessel of the ma-jor coronary arteries.The sensitivity,specificity and predictive value of exercise-inducedU-wave inversion were 29％, 97％ and 91％,respectively.It is proposed that exercise inducedU-wave inversion is a reliable predictive index of CAD.
基金supported by State Key Laboratory of Ocean Engineering Self-Development (GKZD010053-3) and EPSRC (EP/G006482/1)
文摘When ocean waves propagate over the sea floor,dynamic wave pressures and bottom shear stresses exert on the surface of seabed.The bottom shear stresses provide a horizontal loading in the wave-seabed interaction system,while dynamic wave pressures provide a vertical loading in the system.However,the bottom shear stresses have been ignored in most previous studies in the past.In this study,the effects of the bottom shear stresses on the dynamic response in a seabed of finite thickness under wave loading will be examined,based on Biot＇s dynamic poro-elastic theory.In the model,an ＂u-p＂ approximation will be adopted instead of quasi-static model that have been used in most previous studies.Numerical results indicate that the bottom shear stresses has certain influences on the wave-induced seabed dynamic response.Furthermore,wave and soil characteristics have considerable influences on the relative difference of seabed response between the previous model（without shear stresses） and the present model（with shear stresses）.As shown in the parametric study,the relative differences between two models could up to 10% of p0,depending on the amplitude of bottom shear stresses.
