With respect to the gamma spectrum, the energy resolution improves with increase in energy. The counts of full energy peak change with energy, and this approximately complies with the Gaussian distribution. This study...With respect to the gamma spectrum, the energy resolution improves with increase in energy. The counts of full energy peak change with energy, and this approximately complies with the Gaussian distribution. This study mainly examines a method to deconvolve the LaBr_3:Ce gamma spectrum with a detector response matrix constructing algorithm based on energy resolution calibration.In the algorithm, the full width at half maximum(FWHM)of full energy peak was calculated by the cubic spline interpolation algorithm and calibrated by a square root of a quadratic function that changes with the energy. Additionally, the detector response matrix was constructed to deconvolve the gamma spectrum. Furthermore, an improved SNIP algorithm was proposed to eliminate the background. In the experiment, several independent peaks of ^(152)Eu,^(137)Cs, and ^(60)Co sources were detected by a LaBr_3:Ce scintillator that were selected to calibrate the energy resolution. The Boosted Gold algorithm was applied to deconvolve the gamma spectrum. The results showed that the peak position difference between the experiment and the deconvolution was within ± 2 channels and the relative error of peak area was approximately within 0.96–6.74%. Finally, a ^(133) Ba spectrum was deconvolved to verify the efficiency and accuracy of the algorithm in unfolding the overlapped peaks.展开更多
采用有少量反相器和开关(Inverter and Switch,IS)组合的预编码架构设计模拟预编码部分,相比传统移相器结构的混合预编码可以有效降低系统功耗。利用此结构的混合预编码在计算收发端最优的编码矩阵时会变成一个求解复杂的离散组合问题...采用有少量反相器和开关(Inverter and Switch,IS)组合的预编码架构设计模拟预编码部分,相比传统移相器结构的混合预编码可以有效降低系统功耗。利用此结构的混合预编码在计算收发端最优的编码矩阵时会变成一个求解复杂的离散组合问题。针对多天线多用户的毫米波大规模多输入多输出(Multiple Input Multiple Output,MIMO)场景,提出了一种新的优化方案——SVD_CE,可将2个矩阵的联合优化问题转化为2个独立的组合优化问题,基于改进交叉熵(Cross Entropy,CE)算法分别求解编解码矩阵。仿真结果表明,所提方案与已有解决方案相比不会造成系统性能的损失,在取得相同性能时利用CE算法中所需候选集的数量大幅减少,有效降低了求解的复杂度。展开更多
为提高彩色图像的整体感官效果,在研究CES(Color image Enhancement by Scaling)算法出现块效应的原因基础上,提出了一种改进算法,即各向异性扩散滤波器的ICES(Improved Color image Enhancement byScaling)。与CES相比,ICES算法在不增...为提高彩色图像的整体感官效果,在研究CES(Color image Enhancement by Scaling)算法出现块效应的原因基础上,提出了一种改进算法,即各向异性扩散滤波器的ICES(Improved Color image Enhancement byScaling)。与CES相比,ICES算法在不增加计算复杂性的前提下,不仅得到了不逊于CES算法的增强效果,还能极大地抑制块效应。展开更多
基金supported by the National Natural Science Foundation of China(Nos.41374130 and 41604154)
文摘With respect to the gamma spectrum, the energy resolution improves with increase in energy. The counts of full energy peak change with energy, and this approximately complies with the Gaussian distribution. This study mainly examines a method to deconvolve the LaBr_3:Ce gamma spectrum with a detector response matrix constructing algorithm based on energy resolution calibration.In the algorithm, the full width at half maximum(FWHM)of full energy peak was calculated by the cubic spline interpolation algorithm and calibrated by a square root of a quadratic function that changes with the energy. Additionally, the detector response matrix was constructed to deconvolve the gamma spectrum. Furthermore, an improved SNIP algorithm was proposed to eliminate the background. In the experiment, several independent peaks of ^(152)Eu,^(137)Cs, and ^(60)Co sources were detected by a LaBr_3:Ce scintillator that were selected to calibrate the energy resolution. The Boosted Gold algorithm was applied to deconvolve the gamma spectrum. The results showed that the peak position difference between the experiment and the deconvolution was within ± 2 channels and the relative error of peak area was approximately within 0.96–6.74%. Finally, a ^(133) Ba spectrum was deconvolved to verify the efficiency and accuracy of the algorithm in unfolding the overlapped peaks.
文摘为提高彩色图像的整体感官效果,在研究CES(Color image Enhancement by Scaling)算法出现块效应的原因基础上,提出了一种改进算法,即各向异性扩散滤波器的ICES(Improved Color image Enhancement byScaling)。与CES相比,ICES算法在不增加计算复杂性的前提下,不仅得到了不逊于CES算法的增强效果,还能极大地抑制块效应。
