Detecting target echo in the existence of self-screen jamming is a challenging work for radar system, especially when digital radio frequency memory(DRFM) technique is employed that mixes the jamming and target echo b...Detecting target echo in the existence of self-screen jamming is a challenging work for radar system, especially when digital radio frequency memory(DRFM) technique is employed that mixes the jamming and target echo both in spatial and time-frequency domain. The conventional way to solve this problem would suffer from performance degradation when physical target(PT) and false target(FT) are superposed in time. In this paper, we propose a new spatial filter according to the different correlation characteristic between PT and FT. The filter takes the ratio of expected signal power to expected jamming and noise power as the objective function under the constant filter modulus constraint. The optimal filter coefficients are derived with a generalized rayleigh quotient approach. Moreover, we analytically compute the target detection probability and demonstrate the applicability of the proposed method to the correlation coefficient. Monte Carlo simulations are provided to corroborate the proposed studies. Furthermore, the proposed method has simple architecture and low computation complexity, making it easily applied in modern radar system.展开更多
介绍了除渣器、多盘过滤机和压力筛新产品研发背景和性能,包括除渣器IDC-4F在废纸线和卫生纸线的改造,Flowing扇片在白水多盘过滤机上的改造,以及C-b a r筛框在废纸线一段精筛上的改造,这些应用都取得了较好的改造效果,达到了提产节能...介绍了除渣器、多盘过滤机和压力筛新产品研发背景和性能,包括除渣器IDC-4F在废纸线和卫生纸线的改造,Flowing扇片在白水多盘过滤机上的改造,以及C-b a r筛框在废纸线一段精筛上的改造,这些应用都取得了较好的改造效果,达到了提产节能目标。展开更多
针对高效用模式挖掘任务中假阳性模式和冗余模式的判别问题,提出一种基于无限制检验和独立成长率的判别高效用模式挖掘算法UTDHU(Unlimited Testing for Discriminative High Utility pattern mining)。首先,找到目标事务集合中满足效...针对高效用模式挖掘任务中假阳性模式和冗余模式的判别问题,提出一种基于无限制检验和独立成长率的判别高效用模式挖掘算法UTDHU(Unlimited Testing for Discriminative High Utility pattern mining)。首先,找到目标事务集合中满足效用阈值和差异阈值的判别高效用模式;其次,建立前缀项共享树以快速计算每个模式的独立成长率,并基于独立成长率筛除未超过独立阈值的冗余判别高效用模式;最后,使用无限制检验计算余下每个模式的统计显著性度量p值,并根据错误率判断族过滤整体结果中的假阳性判别高效用模式。在4个基准事务集合和2个仿真事务集合上的实验结果表明,相较于Hamm和YBHU(Yekutieli-Benjamini resampling for High Utility pattern mining)等算法,所提算法在模式数量方面输出最少,过滤了至少97.8%的被检验模式;在模式质量方面,所提算法的假阳性判别高效用模式占比低于5.2%,且构造特征的分类准确率高于对比算法至少1.5个百分点;虽然所提算法在运行时间方面慢于Hamm算法,但快于其余3个基于统计显著性检验的算法。可见,所提算法能够有效剔除一定数量的假阳性和冗余判别高效用模式,在挖掘性能上更优,且运行效率更高。展开更多
文摘Detecting target echo in the existence of self-screen jamming is a challenging work for radar system, especially when digital radio frequency memory(DRFM) technique is employed that mixes the jamming and target echo both in spatial and time-frequency domain. The conventional way to solve this problem would suffer from performance degradation when physical target(PT) and false target(FT) are superposed in time. In this paper, we propose a new spatial filter according to the different correlation characteristic between PT and FT. The filter takes the ratio of expected signal power to expected jamming and noise power as the objective function under the constant filter modulus constraint. The optimal filter coefficients are derived with a generalized rayleigh quotient approach. Moreover, we analytically compute the target detection probability and demonstrate the applicability of the proposed method to the correlation coefficient. Monte Carlo simulations are provided to corroborate the proposed studies. Furthermore, the proposed method has simple architecture and low computation complexity, making it easily applied in modern radar system.
文摘针对高效用模式挖掘任务中假阳性模式和冗余模式的判别问题,提出一种基于无限制检验和独立成长率的判别高效用模式挖掘算法UTDHU(Unlimited Testing for Discriminative High Utility pattern mining)。首先,找到目标事务集合中满足效用阈值和差异阈值的判别高效用模式;其次,建立前缀项共享树以快速计算每个模式的独立成长率,并基于独立成长率筛除未超过独立阈值的冗余判别高效用模式;最后,使用无限制检验计算余下每个模式的统计显著性度量p值,并根据错误率判断族过滤整体结果中的假阳性判别高效用模式。在4个基准事务集合和2个仿真事务集合上的实验结果表明,相较于Hamm和YBHU(Yekutieli-Benjamini resampling for High Utility pattern mining)等算法,所提算法在模式数量方面输出最少,过滤了至少97.8%的被检验模式;在模式质量方面,所提算法的假阳性判别高效用模式占比低于5.2%,且构造特征的分类准确率高于对比算法至少1.5个百分点;虽然所提算法在运行时间方面慢于Hamm算法,但快于其余3个基于统计显著性检验的算法。可见,所提算法能够有效剔除一定数量的假阳性和冗余判别高效用模式,在挖掘性能上更优,且运行效率更高。
