传统的信道估计方法未充分利用信道的稀疏性。利用信道冲激响应的稀疏特性,提出了将FOCUSS(Focal Underdetermined System Solver)压缩感知算法应用到信道估计中,从均方误差和正确检测率方面分别与传统最小二乘估计和正交匹配追踪压缩...传统的信道估计方法未充分利用信道的稀疏性。利用信道冲激响应的稀疏特性,提出了将FOCUSS(Focal Underdetermined System Solver)压缩感知算法应用到信道估计中,从均方误差和正确检测率方面分别与传统最小二乘估计和正交匹配追踪压缩感知信道估计相比较。仿真结果表明,本文算法的均方误差较小,正确检测率较高,能够以较少的导频信号获得好的估计性能。展开更多
Hepatocellular carcinoma(HCC) is the sixth-most common type of cancer worldwide. The only definitive treatment modalities capable of achieving a cure are hepatic resection and hepatic transplantation. However, most pa...Hepatocellular carcinoma(HCC) is the sixth-most common type of cancer worldwide. The only definitive treatment modalities capable of achieving a cure are hepatic resection and hepatic transplantation. However, most patients are not candidates for these therapies. Overall, treatment options are driven by the stage of HCC. Early-stage disease is treated with ablative therapies, with radiofrequency ablation the ablative therapy of choice. Microwave ablation and irreversible electroporation are the other upcoming alternatives. Intermediate-stage disease is managed with transarterial chemoembolization(TACE), while advanced-stage disease is managed by sorafenib, with TACE and radioembolization as other alternatives.展开更多
针对观测和传感矩阵都存在噪声扰动的欠定线性系统的稀疏恢复问题,该文基于FOCUSS(FOCal Underdetermined System Solver)算法提出了一种改进算法——SD(Synchronous Descending)-FOCUSS。文中由MAP(最大后验)估计方法推导出系统模型的...针对观测和传感矩阵都存在噪声扰动的欠定线性系统的稀疏恢复问题,该文基于FOCUSS(FOCal Underdetermined System Solver)算法提出了一种改进算法——SD(Synchronous Descending)-FOCUSS。文中由MAP(最大后验)估计方法推导出系统模型的的目标函数,应用松弛迭代算法对其进行优化从而找到近似最优的稀疏解。SD-FOCUSS算法可应用于MMV(多观测向量)模型。可证明SD-FOCUSS是收敛算法;最后用仿真实验展示了与其他算法相比时,新算法在准确性、稳定性等方面的优越性。展开更多
The properties and designment of the strong focusing lens system and the application to metal modification of gear cutting tools are described. The focused ion beam produced by a special three asymmetric voltage lens ...The properties and designment of the strong focusing lens system and the application to metal modification of gear cutting tools are described. The focused ion beam produced by a special three asymmetric voltage lens has the unique features of short midfocal length, strong focusing and omitted focusing electric power. These properties of strong focusing lens system are due to the application of the high energy ratio of 20 to 50 onto the lens.展开更多
文摘传统的信道估计方法未充分利用信道的稀疏性。利用信道冲激响应的稀疏特性,提出了将FOCUSS(Focal Underdetermined System Solver)压缩感知算法应用到信道估计中,从均方误差和正确检测率方面分别与传统最小二乘估计和正交匹配追踪压缩感知信道估计相比较。仿真结果表明,本文算法的均方误差较小,正确检测率较高,能够以较少的导频信号获得好的估计性能。
文摘Hepatocellular carcinoma(HCC) is the sixth-most common type of cancer worldwide. The only definitive treatment modalities capable of achieving a cure are hepatic resection and hepatic transplantation. However, most patients are not candidates for these therapies. Overall, treatment options are driven by the stage of HCC. Early-stage disease is treated with ablative therapies, with radiofrequency ablation the ablative therapy of choice. Microwave ablation and irreversible electroporation are the other upcoming alternatives. Intermediate-stage disease is managed with transarterial chemoembolization(TACE), while advanced-stage disease is managed by sorafenib, with TACE and radioembolization as other alternatives.
文摘针对观测和传感矩阵都存在噪声扰动的欠定线性系统的稀疏恢复问题,该文基于FOCUSS(FOCal Underdetermined System Solver)算法提出了一种改进算法——SD(Synchronous Descending)-FOCUSS。文中由MAP(最大后验)估计方法推导出系统模型的的目标函数,应用松弛迭代算法对其进行优化从而找到近似最优的稀疏解。SD-FOCUSS算法可应用于MMV(多观测向量)模型。可证明SD-FOCUSS是收敛算法;最后用仿真实验展示了与其他算法相比时,新算法在准确性、稳定性等方面的优越性。
文摘The properties and designment of the strong focusing lens system and the application to metal modification of gear cutting tools are described. The focused ion beam produced by a special three asymmetric voltage lens has the unique features of short midfocal length, strong focusing and omitted focusing electric power. These properties of strong focusing lens system are due to the application of the high energy ratio of 20 to 50 onto the lens.
