A kind of calculating method for high order differential expandedby the wavelet scal- ing functions and the of their product used inGalerkin FEM is proposed, so that we can use the wavelet Galerkin FEMto solve boundar...A kind of calculating method for high order differential expandedby the wavelet scal- ing functions and the of their product used inGalerkin FEM is proposed, so that we can use the wavelet Galerkin FEMto solve boundary-value differential equations with orders higherthan two. To combine this method with the Generalized Gaussianintegral method in wavelt theory, we can find That this method hasmany merits in solving mechanical problems, such as the bending ofplates and Those with variable thickness. The numerical results showthat this method is accurate.展开更多
A novel model named Multi-scale Gaussian Processes (MGP) is proposed. Motivated by the ideas of multi-scale representations in the wavelet theory, in the new model, a Gaussian process is represented at a scale by a li...A novel model named Multi-scale Gaussian Processes (MGP) is proposed. Motivated by the ideas of multi-scale representations in the wavelet theory, in the new model, a Gaussian process is represented at a scale by a linear basis that is composed of a scale function and its different translations. Finally the distribution of the targets of the given samples can be obtained at different scales. Compared with the standard Gaussian Processes (GP) model, the MGP model can control its complexity conveniently just by adjusting the scale pa-rameter. So it can trade-off the generalization ability and the empirical risk rapidly. Experiments verify the fea-sibility of the MGP model, and exhibit that its performance is superior to the GP model if appropriate scales are chosen.展开更多
In this paper, an approach is proposed for taking calculations of high order differentials of scaling functions in wavelet theory in order to apply the wavelet Galerkin FEM to numerical analysis of those boundary-valu...In this paper, an approach is proposed for taking calculations of high order differentials of scaling functions in wavelet theory in order to apply the wavelet Galerkin FEM to numerical analysis of those boundary-value problems with order higher than 2. After that, it is realized that the wavelet Galerkin FEM is used to solve mechanical problems such as bending of beams and plates. The numerical results show that this method has good precision.展开更多
Blasting is one of the most economical and efficient mining methods in open-pit mine production.However,behind the huge benefits,it poses a hidden threat to the quality of slope rock mass,stability of slope,and safety...Blasting is one of the most economical and efficient mining methods in open-pit mine production.However,behind the huge benefits,it poses a hidden threat to the quality of slope rock mass,stability of slope,and safety of nearby buildings.In order to explore the influence of blasting vibration on the stability of anti-dip layered rock slopes,herein,the site near the large-scale toppling failure area of Changshanhao gold mine stope of Inner Mongolia Taiping Mining Co.,Ltd.was selected for on-site blasting test and monitoring.The Peak Particle Velocity(PPV)measured at the monitoring point is located on the lower side of the maximum allowable vibration velocity curve that is prepared based on the allowable speed standard evaluation chart in the full frequency domain established by standards practiced in various countries such as German DIN4150,the USBM RI 8507,and Chinese GB6722-2014.This indicates that the blasting vibration has less influence on the location of the monitoring point.The vibration signals obtained in the blasting test were analyzed using the wavelet packet theory,and it was concluded that the blasting vibration signals measured in the anti-dip layered rock slope were mainly concentrated in two frequency bands of 0-80 Hz and 115-160 Hz.The sum of energy of the two frequency bands accounted for more than 99%,wherein,the energy contained in the 0-80 Hz frequency band accounted for more than 85%of the monitoring signals.The vibration signal with 0-80 Hz frequency band monitored at the slope toe was selected for the energy attenuation analysis.The results showed that the energy attenuation decreased in radial,vertical,and tangential directions.Further,the Energy Attenuation Rate per Meter(EARPM)was calculated.In conjunction with the site characteristics analysis,it was found that the energy attenuation rate was significantly affected by the rock mass characteristics of the structural plane.The slope reinforcement project can effectively reduce the absorption of vibration energy by the slope and increase slope stability.展开更多
An optimized damage identification method of beam combined wavelet with neural network is presented in an attempt to improve the calculation iterative speed and accuracy damage identification. The mathematical model i...An optimized damage identification method of beam combined wavelet with neural network is presented in an attempt to improve the calculation iterative speed and accuracy damage identification. The mathematical model is developed to identify the structure damage based on the theory of finite elements and rotation modal parameters. The model is integrated with BP neural network optimization approach which utilizes the Genetic algorithm optimization method. The structural rotation modal parameters are performed with the continuous wavelet transform through the Mexico hat wavelet. The location of structure damage is identified by the maximum of wavelet coefficients. Then, the multi-scale wavelet coefficients modulus maxima are used as the inputs of the BP neural network, and through training and updating the optimal weight and threshold value to obtain the ideal output which is used to describe the degree of structural damage. The obtained results demonstrate the effectiveness of the proposed approach in simultaneously improving the structural damage identification precision including the damage locating and severity.展开更多
Driven by fast development of both virtual reality and volume visualization, we discuss some critical techniques towards building a volumetric VRsystem, specifically the modeling, rendering, and manipulations of a vol...Driven by fast development of both virtual reality and volume visualization, we discuss some critical techniques towards building a volumetric VRsystem, specifically the modeling, rendering, and manipulations of a volumetric scene.Techniques such as voxel-based object simplification, accelerated volume rendering,fast stereo volume rendering, and volumetric 'collision detection' are introduced andimproved, with the idea of demonstrating the possibilities and potential benefits ofincorporating volumetric models into VR systems.展开更多
基金the National Natural Science Foundation of China(No.19772014)the National Outstanding Young Scientist Foundation of China (No.19725207)
文摘A kind of calculating method for high order differential expandedby the wavelet scal- ing functions and the of their product used inGalerkin FEM is proposed, so that we can use the wavelet Galerkin FEMto solve boundary-value differential equations with orders higherthan two. To combine this method with the Generalized Gaussianintegral method in wavelt theory, we can find That this method hasmany merits in solving mechanical problems, such as the bending ofplates and Those with variable thickness. The numerical results showthat this method is accurate.
文摘A novel model named Multi-scale Gaussian Processes (MGP) is proposed. Motivated by the ideas of multi-scale representations in the wavelet theory, in the new model, a Gaussian process is represented at a scale by a linear basis that is composed of a scale function and its different translations. Finally the distribution of the targets of the given samples can be obtained at different scales. Compared with the standard Gaussian Processes (GP) model, the MGP model can control its complexity conveniently just by adjusting the scale pa-rameter. So it can trade-off the generalization ability and the empirical risk rapidly. Experiments verify the fea-sibility of the MGP model, and exhibit that its performance is superior to the GP model if appropriate scales are chosen.
文摘In this paper, an approach is proposed for taking calculations of high order differentials of scaling functions in wavelet theory in order to apply the wavelet Galerkin FEM to numerical analysis of those boundary-value problems with order higher than 2. After that, it is realized that the wavelet Galerkin FEM is used to solve mechanical problems such as bending of beams and plates. The numerical results show that this method has good precision.
基金supported by Open Research Fund of State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences(Grant No.Z020007)。
文摘Blasting is one of the most economical and efficient mining methods in open-pit mine production.However,behind the huge benefits,it poses a hidden threat to the quality of slope rock mass,stability of slope,and safety of nearby buildings.In order to explore the influence of blasting vibration on the stability of anti-dip layered rock slopes,herein,the site near the large-scale toppling failure area of Changshanhao gold mine stope of Inner Mongolia Taiping Mining Co.,Ltd.was selected for on-site blasting test and monitoring.The Peak Particle Velocity(PPV)measured at the monitoring point is located on the lower side of the maximum allowable vibration velocity curve that is prepared based on the allowable speed standard evaluation chart in the full frequency domain established by standards practiced in various countries such as German DIN4150,the USBM RI 8507,and Chinese GB6722-2014.This indicates that the blasting vibration has less influence on the location of the monitoring point.The vibration signals obtained in the blasting test were analyzed using the wavelet packet theory,and it was concluded that the blasting vibration signals measured in the anti-dip layered rock slope were mainly concentrated in two frequency bands of 0-80 Hz and 115-160 Hz.The sum of energy of the two frequency bands accounted for more than 99%,wherein,the energy contained in the 0-80 Hz frequency band accounted for more than 85%of the monitoring signals.The vibration signal with 0-80 Hz frequency band monitored at the slope toe was selected for the energy attenuation analysis.The results showed that the energy attenuation decreased in radial,vertical,and tangential directions.Further,the Energy Attenuation Rate per Meter(EARPM)was calculated.In conjunction with the site characteristics analysis,it was found that the energy attenuation rate was significantly affected by the rock mass characteristics of the structural plane.The slope reinforcement project can effectively reduce the absorption of vibration energy by the slope and increase slope stability.
文摘An optimized damage identification method of beam combined wavelet with neural network is presented in an attempt to improve the calculation iterative speed and accuracy damage identification. The mathematical model is developed to identify the structure damage based on the theory of finite elements and rotation modal parameters. The model is integrated with BP neural network optimization approach which utilizes the Genetic algorithm optimization method. The structural rotation modal parameters are performed with the continuous wavelet transform through the Mexico hat wavelet. The location of structure damage is identified by the maximum of wavelet coefficients. Then, the multi-scale wavelet coefficients modulus maxima are used as the inputs of the BP neural network, and through training and updating the optimal weight and threshold value to obtain the ideal output which is used to describe the degree of structural damage. The obtained results demonstrate the effectiveness of the proposed approach in simultaneously improving the structural damage identification precision including the damage locating and severity.
文摘Driven by fast development of both virtual reality and volume visualization, we discuss some critical techniques towards building a volumetric VRsystem, specifically the modeling, rendering, and manipulations of a volumetric scene.Techniques such as voxel-based object simplification, accelerated volume rendering,fast stereo volume rendering, and volumetric 'collision detection' are introduced andimproved, with the idea of demonstrating the possibilities and potential benefits ofincorporating volumetric models into VR systems.