In order to improve image quality, a novel Retinex algorithm for image enhancement was presented. Different from conventional algorithms, it was based on certain defined points containing the illumination information ...In order to improve image quality, a novel Retinex algorithm for image enhancement was presented. Different from conventional algorithms, it was based on certain defined points containing the illumination information in the intensity image to estimate the illumination. After locating the points, the whole illumination image was computed by an interpolation technique. When attempting to recover the reflectance image, an adaptive method which can be considered as an optimization problem was employed to suppress noise in dark environments and keep details in other areas. For color images, it was taken in the band of each channel separately. Experimental results demonstrate that the proposed algorithm is superior to the traditional Retinex algorithms in image entropy.展开更多
A new method of single sample polarization filtering is proposed. The algorithm is fast and suitable for the polarization processing of stationary or nonstationary polarized disturbed signals with one or more independ...A new method of single sample polarization filtering is proposed. The algorithm is fast and suitable for the polarization processing of stationary or nonstationary polarized disturbed signals with one or more independent disturbances. A ground wave polarimetric radar with the ability of radio disturbance suppression is then introduced. Some numerical results demonstrate the effectiveness of single sample polarization filtering method for ground wave polarimetric radar.展开更多
车用电子水泵(Electronic Water Pump,EWP)的噪声是反映电子水泵性能优劣的重要指标,对其进行主动控制有利于改善车内声品质。为了实现对EWP噪声的主动控制,提出了一种混合随机载波空间矢量脉宽调制(Hybrid Random Carrier Space Vector...车用电子水泵(Electronic Water Pump,EWP)的噪声是反映电子水泵性能优劣的重要指标,对其进行主动控制有利于改善车内声品质。为了实现对EWP噪声的主动控制,提出了一种混合随机载波空间矢量脉宽调制(Hybrid Random Carrier Space Vector Pulse Width Modulation,HRCSVPWM)策略。首先,采用Xorshift算法设计随机序列生成器,以产生随机性较好的随机数,分散集中出现在载波频率及其整数倍频段的大量谐波;其次,结合锯齿波周期函数,增加对脉宽调制(Pulse Width Modulation,PWM)谐波幅值的削弱作用;然后,搭建EWP仿真模型对空间矢量脉宽调制(Space Vector PWM,SVPWM)、随机载波空间矢量脉宽调制(Random Carrier Space Vector PWM,RCSVPWM)和HRCSVPWM控制策略的谐波抑制效果进行对比分析,验证HRCSVPWM控制策略对PWM谐波的抑制能力;最后,搭建EWP噪声试验平台,对EWP在3种控制策略下的噪声进行分析。结果表明,HRCSVPWM控制策略可使EWP的噪声声压级得到明显下降,平均下降约为3 dB。展开更多
为解决风力发电直接并网所产生的功率波动问题,提出了一种基于改进阿基米德优化算法融合自适应噪声完全集合经验模态分解(complete ensemble EMD with adaptive noise,CEEMDAN)的容量配置方法。采用由限幅与滑动平均结合的加权滤波算法...为解决风力发电直接并网所产生的功率波动问题,提出了一种基于改进阿基米德优化算法融合自适应噪声完全集合经验模态分解(complete ensemble EMD with adaptive noise,CEEMDAN)的容量配置方法。采用由限幅与滑动平均结合的加权滤波算法平滑风电出力,同时减小平滑结果的滞后性,得到风电并网功率和混合储能系统(hybrid energy storage system,HESS)参考功率。为了合理分配HESS的内部功率,借助CEEMDAN分解HESS的参考功率,得到高低频分量。综合考虑HESS功率和容量、荷电状态(state of charge,SOC)与负荷缺点率等因素,构建以年综合成本最小为目标的容量优化配置模型并采用改进阿基米德优化算法求解。基于实际算例进行仿真分析,结果表明,与原始风电并网相比,HESS配置方案将波动率减少了13.538%,平滑度提高了16.057%。相较于传统单一储能平抑效果更加明显,减少了容量配置。同时,对比传统阿基米德优化算法节省了15.325%的投资成本。展开更多
基金Project(61071162) supported by the National Natural Science Foundation of China
文摘In order to improve image quality, a novel Retinex algorithm for image enhancement was presented. Different from conventional algorithms, it was based on certain defined points containing the illumination information in the intensity image to estimate the illumination. After locating the points, the whole illumination image was computed by an interpolation technique. When attempting to recover the reflectance image, an adaptive method which can be considered as an optimization problem was employed to suppress noise in dark environments and keep details in other areas. For color images, it was taken in the band of each channel separately. Experimental results demonstrate that the proposed algorithm is superior to the traditional Retinex algorithms in image entropy.
文摘A new method of single sample polarization filtering is proposed. The algorithm is fast and suitable for the polarization processing of stationary or nonstationary polarized disturbed signals with one or more independent disturbances. A ground wave polarimetric radar with the ability of radio disturbance suppression is then introduced. Some numerical results demonstrate the effectiveness of single sample polarization filtering method for ground wave polarimetric radar.
文摘车用电子水泵(Electronic Water Pump,EWP)的噪声是反映电子水泵性能优劣的重要指标,对其进行主动控制有利于改善车内声品质。为了实现对EWP噪声的主动控制,提出了一种混合随机载波空间矢量脉宽调制(Hybrid Random Carrier Space Vector Pulse Width Modulation,HRCSVPWM)策略。首先,采用Xorshift算法设计随机序列生成器,以产生随机性较好的随机数,分散集中出现在载波频率及其整数倍频段的大量谐波;其次,结合锯齿波周期函数,增加对脉宽调制(Pulse Width Modulation,PWM)谐波幅值的削弱作用;然后,搭建EWP仿真模型对空间矢量脉宽调制(Space Vector PWM,SVPWM)、随机载波空间矢量脉宽调制(Random Carrier Space Vector PWM,RCSVPWM)和HRCSVPWM控制策略的谐波抑制效果进行对比分析,验证HRCSVPWM控制策略对PWM谐波的抑制能力;最后,搭建EWP噪声试验平台,对EWP在3种控制策略下的噪声进行分析。结果表明,HRCSVPWM控制策略可使EWP的噪声声压级得到明显下降,平均下降约为3 dB。
文摘为解决风力发电直接并网所产生的功率波动问题,提出了一种基于改进阿基米德优化算法融合自适应噪声完全集合经验模态分解(complete ensemble EMD with adaptive noise,CEEMDAN)的容量配置方法。采用由限幅与滑动平均结合的加权滤波算法平滑风电出力,同时减小平滑结果的滞后性,得到风电并网功率和混合储能系统(hybrid energy storage system,HESS)参考功率。为了合理分配HESS的内部功率,借助CEEMDAN分解HESS的参考功率,得到高低频分量。综合考虑HESS功率和容量、荷电状态(state of charge,SOC)与负荷缺点率等因素,构建以年综合成本最小为目标的容量优化配置模型并采用改进阿基米德优化算法求解。基于实际算例进行仿真分析,结果表明,与原始风电并网相比,HESS配置方案将波动率减少了13.538%,平滑度提高了16.057%。相较于传统单一储能平抑效果更加明显,减少了容量配置。同时,对比传统阿基米德优化算法节省了15.325%的投资成本。
