The head-related transfer function(HRTF)involves the cues for human auditory localization,which turns it into an essential item of virtual auditory display technology.In practice,the interpolation of HRTF is necessary...The head-related transfer function(HRTF)involves the cues for human auditory localization,which turns it into an essential item of virtual auditory display technology.In practice,the interpolation of HRTF is necessary for the virtual auditory display systems to achieve high spatial resolution.Traditional geometric-based interpolation methods are generally restrained by the spatial distribution of reference on HRTF.When the spatial distribution is sparse,the accuracy of interpolation decreases significantly.Therefore,an interpolation method using the common-pole/zero model and the fitting neural network is proposed.First,we propose a common-pole/zero model to represent HRTFs across multiple subjects,in which the low-dimensional features of the measured HRTFs are extracted.Then,for a new spatial direction,we predict the corresponding low-dimensional HRTF with a fitting neural network.Finally,we reconstruct the high-dimensional HRTF from the predicted low-dimensional HRTF.The simulation results suggest that the proposed method outperforms other interpolation methods such as Linear_AMBC,Bilinear_AMBC,and the Combination method.展开更多
Modelling and simulation of projectile flight is at the core of ballistic computer software and is essential to the study of performance of rifles and projectiles in various engagement conditions.An effective and repr...Modelling and simulation of projectile flight is at the core of ballistic computer software and is essential to the study of performance of rifles and projectiles in various engagement conditions.An effective and representative numerical model of projectile flight requires a relatively good approximation of the aerodynamics.The aerodynamic coefficients of the projectile model should be described as a series of piecewise polynomial functions of the Mach number that ideally meet the following conditions:they are continuous,differentiable at least once,and have a relatively low degree.The paper provides the steps needed to generate such piecewise polynomial functions using readily available tools,and then compares Piecewise Cubic Hermite Interpolating Polynomial(PCHIP),cubic splines,and piecewise linear functions,and their variant,as potential curve fitting methods to approximate the aerodynamics of a generic small arms projectile.A key contribution of the paper is the application of PCHIP to the approximation of projectile aerodynamics,and its evaluation against a set of criteria.Finally,the paper provides a baseline assessment of the impact of the polynomial functions on flight trajectory predictions obtained with 6-degree-of-freedom simulations of a generic projectile.展开更多
基金the National Key R&D Program of China(No.2017YFB1002803)National Nature Science Foundation of China(No.61801334,No.61761044)Basic Research Project of Science and Technology Plan of Shenzhen(JCYJ20170818143246278)。
文摘The head-related transfer function(HRTF)involves the cues for human auditory localization,which turns it into an essential item of virtual auditory display technology.In practice,the interpolation of HRTF is necessary for the virtual auditory display systems to achieve high spatial resolution.Traditional geometric-based interpolation methods are generally restrained by the spatial distribution of reference on HRTF.When the spatial distribution is sparse,the accuracy of interpolation decreases significantly.Therefore,an interpolation method using the common-pole/zero model and the fitting neural network is proposed.First,we propose a common-pole/zero model to represent HRTFs across multiple subjects,in which the low-dimensional features of the measured HRTFs are extracted.Then,for a new spatial direction,we predict the corresponding low-dimensional HRTF with a fitting neural network.Finally,we reconstruct the high-dimensional HRTF from the predicted low-dimensional HRTF.The simulation results suggest that the proposed method outperforms other interpolation methods such as Linear_AMBC,Bilinear_AMBC,and the Combination method.
文摘Modelling and simulation of projectile flight is at the core of ballistic computer software and is essential to the study of performance of rifles and projectiles in various engagement conditions.An effective and representative numerical model of projectile flight requires a relatively good approximation of the aerodynamics.The aerodynamic coefficients of the projectile model should be described as a series of piecewise polynomial functions of the Mach number that ideally meet the following conditions:they are continuous,differentiable at least once,and have a relatively low degree.The paper provides the steps needed to generate such piecewise polynomial functions using readily available tools,and then compares Piecewise Cubic Hermite Interpolating Polynomial(PCHIP),cubic splines,and piecewise linear functions,and their variant,as potential curve fitting methods to approximate the aerodynamics of a generic small arms projectile.A key contribution of the paper is the application of PCHIP to the approximation of projectile aerodynamics,and its evaluation against a set of criteria.Finally,the paper provides a baseline assessment of the impact of the polynomial functions on flight trajectory predictions obtained with 6-degree-of-freedom simulations of a generic projectile.
