The Experts below are selected from a list of 167259 Experts worldwide ranked by ideXlab platform
Kai Zhang - One of the best experts on this subject based on the ideXlab platform.
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curved boundary conditions of the lattice boltzmann method for simulating microgaseous flows in the slip flow regime
arXiv: Computational Physics, 2020Co-Authors: Liang Wang, Shi Tao, Kai ZhangAbstract:The lattice Boltzmann method (LBM) has shown its promising capability in simulating microscale gas flows. However, the suitable boundary condition is still one of the critical issues for the LBM to model microgaseous flows involving curved geometries. In this paper, a local boundary condition of the LBM is proposed to treat curved solid walls of microgaseous flows. The developed boundary treatment combines the Maxwellian diffuse reflection scheme and a single-node boundary scheme which contains a Free Parameter as well as the distance ratio. The curved boundary condition is analyzed within the multiple-relaxation-time (MRT) model for a unidirectional microflow. It is shown that the derived slip velocity depends on the Free Parameter as well as the distance ratio and relaxation times. By virtue of the Free Parameter, the combination Parameter and the uniform relaxation time are theoretically determined to realize the accurate slip boundary condition. In addition, it is found that besides the halfway diffuse-bounce-back (DBB) scheme, previous curved boundary schemes only containing the distance ratio cannot ensure uniform relaxation times to realize the slip boundary condition. Some numerical examples with planar and curved boundaries are carried out to validate the present curved boundary scheme. The good and robust consistency of numerical predictions with analytical solutions demonstrates our theoretical analysis.
Venkatesh R Babu - One of the best experts on this subject based on the ideXlab platform.
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data Free Parameter pruning for deep neural networks
arXiv: Computer Vision and Pattern Recognition, 2015Co-Authors: Suraj Srinivas, Venkatesh R BabuAbstract:Deep Neural nets (NNs) with millions of Parameters are at the heart of many state-of-the-art computer vision systems today. However, recent works have shown that much smaller models can achieve similar levels of performance. In this work, we address the problem of pruning Parameters in a trained NN model. Instead of removing individual weights one at a time as done in previous works, we remove one neuron at a time. We show how similar neurons are redundant, and propose a systematic way to remove them. Our experiments in pruning the densely connected layers show that we can remove upto 85\% of the total Parameters in an MNIST-trained network, and about 35\% for AlexNet without significantly affecting performance. Our method can be applied on top of most networks with a fully connected layer to give a smaller network.
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data Free Parameter pruning for deep neural networks
British Machine Vision Conference, 2015Co-Authors: Suraj Srinivas, Venkatesh R BabuAbstract:Deep Neural nets (NNs) with millions of Parameters are at the heart of many state-of-the-art computer vision systems today. However, recent works have shown that much smaller models can achieve similar levels of performance. In this work, we address the problem of pruning Parameters in a trained NN model. Instead of removing individual weights one at a time as done in previous works, we remove one neuron at a time. We show how similar neurons are redundant, and propose a systematic way to remove them. Unlike previous works, our pruning method does not require access to any training/validation data.
D B H Tay - One of the best experts on this subject based on the ideXlab platform.
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a class of lifting based integer wavelet transform
International Conference on Image Processing, 2001Co-Authors: D B H TayAbstract:A class of integer wavelet transform (IWT) which are parametrized simply by one Free Parameter is presented . The class of IWT is obtained by a lifting based factorization on a class of 9/7 filter pair. The class includes the celebrated 9/7 filter pair of Cohen, Daubechies and Feauveau which is adopted in the upcoming JPEG2000 image compression standard. Within this class are lifting filters with simple rational coefficients which are close in characteristics to the irrational coefficient 9/7 pair employed in JPEG2000. By adjusting the Free Parameter, IWT with different properties and characteristics can be obtained. A study of the non-linearity of this class of IWT is also performed.
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families of binary coefficient biorthogonal wavelet filters
Electronics Letters, 2000Co-Authors: D B H TayAbstract:Two families of binary coefficient biorthogonal wavelet filters are presented. Binary coefficient filters can be implemented efficiently without using any multipliers. By adjusting the Free Parameter, filters with different characteristics can be easily obtained while guaranteeing that the coefficients will always be binary.
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families of binary coefficient biorthogonal wavelet filters
International Symposium on Circuits and Systems, 2000Co-Authors: D B H TayAbstract:Two families of binary coefficient biorthogonal wavelet filters are presented in this paper. A binary (or dyadic) coefficient is an integer divided by a power of 2. The filters can be implemented efficiently without using any multipliers. The technique that is used to obtain the filters, hinges on the idea of Freeing some of the zeros of the Lagrange Halfband Filter (LHBF) to allow some degree of Freedom in choosing the coefficients. The first family is the 9/7 pairs and the second is the 6/10 pairs. Filters within the family are parametrized in a simple manner by a Free Parameter. By adjusting the Free Parameter, filters with different characteristics can be easily obtained while guaranteeing that the coefficients will always be binary.
Stefan Leupold - One of the best experts on this subject based on the ideXlab platform.
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two hadron saturation for the pseudoscalar vector vector correlator and phenomenological applications
European Physical Journal C, 2015Co-Authors: T Husek, Stefan LeupoldAbstract:The pseudoscalar–vector–vector correlator is constructed using two meson multiplets in the vector and two in the pseudoscalar channel. The Parameters are constrained by the operator product expansion at leading order where two or all three momenta are considered as large. Demanding in addition the Brodsky–Lepage limit one obtains (in the chiral limit) a pion-vector-vector ( $$\pi $$ VV) correlator with only one Free Parameter. The singly virtual pion transition form factor $$\mathcal F_{\pi ^0\gamma \gamma ^*}$$ and the decay width of $$\omega \rightarrow \pi ^0\gamma $$ are independent of this Parameter and can serve as cross-checks of the results. The Free Parameter is determined from a fit of the $$\omega $$ – $$\pi $$ transition form factor $$\mathcal F_{\pi ^0\omega \gamma ^{*}}$$ . The resulting $$\pi $$ VV correlator is used to calculate the decay widths $$\omega \rightarrow \pi ^0e^{+}e^{-}$$ and $$\omega \rightarrow \pi ^0\mu ^{+}\mu ^{-}$$ and finally the widths of the rare decay $$\pi ^0\rightarrow e^{+}e^{-}$$ and of the Dalitz decay $$\pi ^0\rightarrow e^{+}e^{-}\gamma $$ . Incorporating radiative QED corrections the calculations of $$\pi ^0$$ decays are compared to the KTeV results. We find a deviation of 2 $$\sigma $$ or less for the rare pion decay.
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two hadron saturation for the pseudoscalar vector vector correlator and phenomenological applications
arXiv: High Energy Physics - Phenomenology, 2015Co-Authors: T Husek, Stefan LeupoldAbstract:The pseudoscalar-vector-vector correlator is constructed using two meson multiplets in the vector and two in the pseudoscalar channel. The Parameters are constrained by the operator product expansion at leading order where two or all three momenta are considered as large. Demanding in addition the Brodsky-Lepage limit one obtains (in the chiral limit) a pion-vector-vector correlator with only one Free Parameter. The singly virtual pion transition form factor and the decay width of omega to pion and photon are independent of this Parameter and can serve as cross-checks of the results. The Free Parameter is determined from a fit of the omega-pion transition form factor. The resulting pion-vector-vector correlator is used to calculate the decay widths of omega to pion and dielectron and to pion and dimuon and finally the widths of the rare decay pion to dielectron and of the Dalitz decay pion to photon and dielectron. Incorporating radiative QED corrections the calculations of neutral-pion decays are compared to the KTeV results. We find a deviation of 2 sigma or less for the rare pion decay.
Liang Wang - One of the best experts on this subject based on the ideXlab platform.
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curved boundary conditions of the lattice boltzmann method for simulating microgaseous flows in the slip flow regime
arXiv: Computational Physics, 2020Co-Authors: Liang Wang, Shi Tao, Kai ZhangAbstract:The lattice Boltzmann method (LBM) has shown its promising capability in simulating microscale gas flows. However, the suitable boundary condition is still one of the critical issues for the LBM to model microgaseous flows involving curved geometries. In this paper, a local boundary condition of the LBM is proposed to treat curved solid walls of microgaseous flows. The developed boundary treatment combines the Maxwellian diffuse reflection scheme and a single-node boundary scheme which contains a Free Parameter as well as the distance ratio. The curved boundary condition is analyzed within the multiple-relaxation-time (MRT) model for a unidirectional microflow. It is shown that the derived slip velocity depends on the Free Parameter as well as the distance ratio and relaxation times. By virtue of the Free Parameter, the combination Parameter and the uniform relaxation time are theoretically determined to realize the accurate slip boundary condition. In addition, it is found that besides the halfway diffuse-bounce-back (DBB) scheme, previous curved boundary schemes only containing the distance ratio cannot ensure uniform relaxation times to realize the slip boundary condition. Some numerical examples with planar and curved boundaries are carried out to validate the present curved boundary scheme. The good and robust consistency of numerical predictions with analytical solutions demonstrates our theoretical analysis.
