The upgrade project of the Beijing Electron Positron Collider （BEPCII） and its injector linac is working well. The linac upgrade aims at a higher injection rate of 5OmA/min into the storage ring, which requires an i...The upgrade project of the Beijing Electron Positron Collider （BEPCII） and its injector linac is working well. The linac upgrade aims at a higher injection rate of 5OmA/min into the storage ring, which requires an injected beam with low emittance, low energy spread and high beam orbit and energy stabilities. This goal is finally reached recently by upgrading the linac components and by dealing with rich and practical beam physics, which are described in this study.展开更多
In this paper, we propose novel hardware architecture for intra 16 × 16 module for the macroblock engine of a new video coding standard H.264. To reduce the cycle of intra prediction 16 × 16, transform/quant...In this paper, we propose novel hardware architecture for intra 16 × 16 module for the macroblock engine of a new video coding standard H.264. To reduce the cycle of intra prediction 16 × 16, transform/quantization, and inverse quantization/inverse transform of H.264, an advanced method for different operation is proposed. This architecture can process one macroblock in 208 cycles for all cases of macroblock type by processing 4 × 4 Hadamard transform and quantization during 16 × 16 prediction. This module was designed using VHDL Hardware Description Language (HDL) and works with a 160 MHz frequency using ALTERA NIOS-II development board with Stratix II EP2S60F1020C3 FPGA. The system also includes software running on an NIOS-II processor in order to implementing the pre-processing and the post-processing functions. Finally, the execution time of our HW solution is decreased by 26% when compared with the previous work.展开更多
Abstract A transonic, high Reynolds number natural laminar flow airfoil is designed and studied. The γ-θ transition model is combined with the shear stress transport （SST） k-w turbulence model to predict the trans...Abstract A transonic, high Reynolds number natural laminar flow airfoil is designed and studied. The γ-θ transition model is combined with the shear stress transport （SST） k-w turbulence model to predict the transition region for a laminar-turbulent boundary layer. The non-uniform free-form deformation （NFFD） method based on the non-uniform rational B-spline （NURBS） basis function is introduced to the airfoil parameterization. The non-dominated sorting genetic algorithm-II （NSGA-II） is used as the search algo- rithm, and the surrogate model based on the Kriging models is introduced to improve the efficiency of the optimization system. The optimization system is set up based on the above technologies, and the robust design about the uncertainty of the Mach number is carried out for NASA0412 airfoil. The optimized airfoil is analyzed and compared with the original airfoil. The results show that natural laminar flow can be achieved on a supercritical airfoil to improve the aerodynamic characteristic of airfoils.展开更多
文摘The upgrade project of the Beijing Electron Positron Collider （BEPCII） and its injector linac is working well. The linac upgrade aims at a higher injection rate of 5OmA/min into the storage ring, which requires an injected beam with low emittance, low energy spread and high beam orbit and energy stabilities. This goal is finally reached recently by upgrading the linac components and by dealing with rich and practical beam physics, which are described in this study.
文摘In this paper, we propose novel hardware architecture for intra 16 × 16 module for the macroblock engine of a new video coding standard H.264. To reduce the cycle of intra prediction 16 × 16, transform/quantization, and inverse quantization/inverse transform of H.264, an advanced method for different operation is proposed. This architecture can process one macroblock in 208 cycles for all cases of macroblock type by processing 4 × 4 Hadamard transform and quantization during 16 × 16 prediction. This module was designed using VHDL Hardware Description Language (HDL) and works with a 160 MHz frequency using ALTERA NIOS-II development board with Stratix II EP2S60F1020C3 FPGA. The system also includes software running on an NIOS-II processor in order to implementing the pre-processing and the post-processing functions. Finally, the execution time of our HW solution is decreased by 26% when compared with the previous work.
文摘Abstract A transonic, high Reynolds number natural laminar flow airfoil is designed and studied. The γ-θ transition model is combined with the shear stress transport （SST） k-w turbulence model to predict the transition region for a laminar-turbulent boundary layer. The non-uniform free-form deformation （NFFD） method based on the non-uniform rational B-spline （NURBS） basis function is introduced to the airfoil parameterization. The non-dominated sorting genetic algorithm-II （NSGA-II） is used as the search algo- rithm, and the surrogate model based on the Kriging models is introduced to improve the efficiency of the optimization system. The optimization system is set up based on the above technologies, and the robust design about the uncertainty of the Mach number is carried out for NASA0412 airfoil. The optimized airfoil is analyzed and compared with the original airfoil. The results show that natural laminar flow can be achieved on a supercritical airfoil to improve the aerodynamic characteristic of airfoils.
