The discontinuous Galerkin （DO） or local discontinuous Galerkin （LDG） method is a spatial discretization procedure for convection-diffusion equations, which employs useful features from high resolution finite volu...The discontinuous Galerkin （DO） or local discontinuous Galerkin （LDG） method is a spatial discretization procedure for convection-diffusion equations, which employs useful features from high resolution finite volume schemes, such as the exact or approximate Riemann solvers serving as numerical fluxes and limiters. The Lax- Wendroff time discretization procedure is an altemative method for time discretization to the popular total variation diminishing （TVD） Runge-Kutta time discretizations. In this paper, we develop fluxes for the method of DG with Lax-Wendroff time discretization procedure （LWDG） based on different numerical fluxes for finite volume or finite difference schemes, including the first-order monotone fluxes such as the Lax-Friedfichs flux, Godunov flux, the Engquist-Osher flux etc. and the second-order TVD fluxes. We systematically investigate the performance of the LWDG methods based on these different numerical fluxes for convection terms with the objective of obtaining better performance by choosing suitable numerical fluxes. The detailed numerical study is mainly performed for the one-dimensional system case, addressing the issues of CPU cost, accuracy, non-oscillatory property, and resolution of discontinuities. Numerical tests are also performed for two dimensional systems.展开更多
Age estimation in short speech utterances finds many applications in daily life like human-robot interaction,custom call routing,targeted marketing,user-profiling,etc.Despite the comprehensive studies carried out to e...Age estimation in short speech utterances finds many applications in daily life like human-robot interaction,custom call routing,targeted marketing,user-profiling,etc.Despite the comprehensive studies carried out to extract descriptive features,the estimation errors(i.e.years)are still high.In this study,an automatic system is proposed to estimate age in short speech utterances without depending on the text as well as the speaker.Firstly,four groups of features are extracted from each utterance frame using hybrid techniques and methods.After that,10 statistical functionals are measured for each extracted feature dimension.Then,the extracted feature dimensions are normalized and reduced using the Quantile method and the Linear Discriminant Analysis(LDA)method,respectively.Finally,the speaker’s age is estimated based on a multi-class classification approach by using the Extreme Gradient Boosting(XGBoost)classifier.Experiments have been carried out on the TIMIT dataset to measure the performance of the proposed system.The Mean Absolute Error(MAE)of the suggested system is 4.68 years,and 4.98 years,the Root Mean Square Error(RMSE)is 8.05 and 6.97,respectively,for female and male speakers.The results show a clear relative improvement in terms of MAE up to 28%and 10%for female and male speakers,respectively,in comparison to related works that utilized the TIMIT dataset.展开更多
基金supported by the European project ADIGMA on the development of innovative solution algorithms for aerodynamic simulations,NSFC grant 10671091,SRF for ROCS,SEM and JSNSF BK2006511.
文摘The discontinuous Galerkin （DO） or local discontinuous Galerkin （LDG） method is a spatial discretization procedure for convection-diffusion equations, which employs useful features from high resolution finite volume schemes, such as the exact or approximate Riemann solvers serving as numerical fluxes and limiters. The Lax- Wendroff time discretization procedure is an altemative method for time discretization to the popular total variation diminishing （TVD） Runge-Kutta time discretizations. In this paper, we develop fluxes for the method of DG with Lax-Wendroff time discretization procedure （LWDG） based on different numerical fluxes for finite volume or finite difference schemes, including the first-order monotone fluxes such as the Lax-Friedfichs flux, Godunov flux, the Engquist-Osher flux etc. and the second-order TVD fluxes. We systematically investigate the performance of the LWDG methods based on these different numerical fluxes for convection terms with the objective of obtaining better performance by choosing suitable numerical fluxes. The detailed numerical study is mainly performed for the one-dimensional system case, addressing the issues of CPU cost, accuracy, non-oscillatory property, and resolution of discontinuities. Numerical tests are also performed for two dimensional systems.
文摘Age estimation in short speech utterances finds many applications in daily life like human-robot interaction,custom call routing,targeted marketing,user-profiling,etc.Despite the comprehensive studies carried out to extract descriptive features,the estimation errors(i.e.years)are still high.In this study,an automatic system is proposed to estimate age in short speech utterances without depending on the text as well as the speaker.Firstly,four groups of features are extracted from each utterance frame using hybrid techniques and methods.After that,10 statistical functionals are measured for each extracted feature dimension.Then,the extracted feature dimensions are normalized and reduced using the Quantile method and the Linear Discriminant Analysis(LDA)method,respectively.Finally,the speaker’s age is estimated based on a multi-class classification approach by using the Extreme Gradient Boosting(XGBoost)classifier.Experiments have been carried out on the TIMIT dataset to measure the performance of the proposed system.The Mean Absolute Error(MAE)of the suggested system is 4.68 years,and 4.98 years,the Root Mean Square Error(RMSE)is 8.05 and 6.97,respectively,for female and male speakers.The results show a clear relative improvement in terms of MAE up to 28%and 10%for female and male speakers,respectively,in comparison to related works that utilized the TIMIT dataset.
