Squeezed reservoir engineering is a powerful technique in quantum information that combines the features of squeezing and reservoir engineering to create and stabilize non-classical quantum states. In this paper, we f...Squeezed reservoir engineering is a powerful technique in quantum information that combines the features of squeezing and reservoir engineering to create and stabilize non-classical quantum states. In this paper, we focus on the previously neglected aspect of the impact of the squeezing phase on the precision of quantum phase and amplitude estimation based on a simple model of a two-level system(TLS) interacting with a squeezed reservoir. We derive the optimal squeezed phase-matching conditions for phase φ and amplitude θ parameters, which are crucial for enhancing the precision of quantum parameter estimation. The robustness of the squeezing-enhanced quantum Fisher information against departures from these conditions is examined, demonstrating that minor deviations from phase-matching can still result in remarkable precision of estimation. Additionally, we provide a geometric interpretation of the squeezed phase-matching conditions from the classical motion of a TLS on the Bloch sphere. Our research contributes to a deeper understanding of the operational requirements for employing squeezed reservoir engineering to advance quantum parameter estimation.展开更多
旋转叶片是航空发动机的关键易损件,需要对其进行状态监测。叶端定时(Blade tip timing,BTT)是一种有效的旋转叶片非接触监测方法。然而,传统的叶端定时严重依赖键相信号,叶端定时信号存在严重的欠采样问题。对此,提出了一种基于叶片振...旋转叶片是航空发动机的关键易损件,需要对其进行状态监测。叶端定时(Blade tip timing,BTT)是一种有效的旋转叶片非接触监测方法。然而,传统的叶端定时严重依赖键相信号,叶端定时信号存在严重的欠采样问题。对此,提出了一种基于叶片振动差的正交匹配追踪(Orthogonal matching pursuit,OMP)方法来提取叶片固有频率。首先,使用叶端定时传感器计算叶片振动差。然后,构建叶片振动差的稀疏模型,在变转速情况下使用正交匹配追踪方法对叶片振动差信号进行分解,提取叶片振动振幅和固有频率。通过数值仿真验证了该方法的有效性和鲁棒性,并在叶端定时试验台上进行试验。结果表明,该方法可以准确识别叶片异步振动的振幅和固有频率。展开更多
针对双目结构光三维重建在左右图像的立体匹配过程中匹配基源选取不当造成的重建精度低等问题,提出一种基于绝对相位的匹配方法,从而降低误匹配率,提高重建精度。首先,在相移法与多频外差法求解的绝对相位基础上,利用极线约束对左右图...针对双目结构光三维重建在左右图像的立体匹配过程中匹配基源选取不当造成的重建精度低等问题,提出一种基于绝对相位的匹配方法,从而降低误匹配率,提高重建精度。首先,在相移法与多频外差法求解的绝对相位基础上,利用极线约束对左右图像像素点采用全局搜索与局部搜索创建搜索匹配区域;然后对搜索区域进行3次样条插值实现亚像素立体匹配;最后利用三角测距原理完成匹配点二维坐标到三维坐标的转换,实现对目标表面的三维重建。实验结果表明:本文提出的方法较绝对误差和(Sum of Absolute Differences,SAD)与误差平方和(Sum of Squared Differences,SDD)匹配算法在匹配耗时上缩短了87.77%,在重建精度上分别提高了77.75%和90%,具有较强的通用性和实用性。同时三维重建后的点云无水波纹现象,表面平整光滑更接近实物。展开更多
智慧园区各类新兴业务在电力物联网(power internet of things,PIo T)设备提供的数据支持下开展。这些业务具有严格的时间同步要求。如何在现有电力线载波通信(power line carrier,PLC)的基础上实现高精度、高可靠时间同步成为关键问题...智慧园区各类新兴业务在电力物联网(power internet of things,PIo T)设备提供的数据支持下开展。这些业务具有严格的时间同步要求。如何在现有电力线载波通信(power line carrier,PLC)的基础上实现高精度、高可靠时间同步成为关键问题。针对上述问题,首先,该文建立基于PLC的智慧园区电力物联网精准时间同步网络模型,根据改进精准时间协议(precision time protocol,PTP)计算同步误差,在此基础上,建立基于数字锁相环的频率偏移补偿模型,降低累积误差;其次,提出站点(station,STA)时间同步误差最小化问题;最后,提出基于经验匹配的电力物联网精准时间同步算法,通过调整时间同步匹配成本,优化STA的时间同步路径选择策略。仿真结果表明,所提方法能有效提高时间同步精度。展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 12265004)Jiangxi Provincial Natural Science Foundation (Grant No. 20242BAB26010)+1 种基金the National Natural Science Foundation of China (Grant No. 12365003)Jiangxi Provincial Natural Science Foundation (Grant Nos. 20212ACB211004 and 20212BAB201014)。
文摘Squeezed reservoir engineering is a powerful technique in quantum information that combines the features of squeezing and reservoir engineering to create and stabilize non-classical quantum states. In this paper, we focus on the previously neglected aspect of the impact of the squeezing phase on the precision of quantum phase and amplitude estimation based on a simple model of a two-level system(TLS) interacting with a squeezed reservoir. We derive the optimal squeezed phase-matching conditions for phase φ and amplitude θ parameters, which are crucial for enhancing the precision of quantum parameter estimation. The robustness of the squeezing-enhanced quantum Fisher information against departures from these conditions is examined, demonstrating that minor deviations from phase-matching can still result in remarkable precision of estimation. Additionally, we provide a geometric interpretation of the squeezed phase-matching conditions from the classical motion of a TLS on the Bloch sphere. Our research contributes to a deeper understanding of the operational requirements for employing squeezed reservoir engineering to advance quantum parameter estimation.
文摘旋转叶片是航空发动机的关键易损件,需要对其进行状态监测。叶端定时(Blade tip timing,BTT)是一种有效的旋转叶片非接触监测方法。然而,传统的叶端定时严重依赖键相信号,叶端定时信号存在严重的欠采样问题。对此,提出了一种基于叶片振动差的正交匹配追踪(Orthogonal matching pursuit,OMP)方法来提取叶片固有频率。首先,使用叶端定时传感器计算叶片振动差。然后,构建叶片振动差的稀疏模型,在变转速情况下使用正交匹配追踪方法对叶片振动差信号进行分解,提取叶片振动振幅和固有频率。通过数值仿真验证了该方法的有效性和鲁棒性,并在叶端定时试验台上进行试验。结果表明,该方法可以准确识别叶片异步振动的振幅和固有频率。
文摘针对双目结构光三维重建在左右图像的立体匹配过程中匹配基源选取不当造成的重建精度低等问题,提出一种基于绝对相位的匹配方法,从而降低误匹配率,提高重建精度。首先,在相移法与多频外差法求解的绝对相位基础上,利用极线约束对左右图像像素点采用全局搜索与局部搜索创建搜索匹配区域;然后对搜索区域进行3次样条插值实现亚像素立体匹配;最后利用三角测距原理完成匹配点二维坐标到三维坐标的转换,实现对目标表面的三维重建。实验结果表明:本文提出的方法较绝对误差和(Sum of Absolute Differences,SAD)与误差平方和(Sum of Squared Differences,SDD)匹配算法在匹配耗时上缩短了87.77%,在重建精度上分别提高了77.75%和90%,具有较强的通用性和实用性。同时三维重建后的点云无水波纹现象,表面平整光滑更接近实物。
文摘智慧园区各类新兴业务在电力物联网(power internet of things,PIo T)设备提供的数据支持下开展。这些业务具有严格的时间同步要求。如何在现有电力线载波通信(power line carrier,PLC)的基础上实现高精度、高可靠时间同步成为关键问题。针对上述问题,首先,该文建立基于PLC的智慧园区电力物联网精准时间同步网络模型,根据改进精准时间协议(precision time protocol,PTP)计算同步误差,在此基础上,建立基于数字锁相环的频率偏移补偿模型,降低累积误差;其次,提出站点(station,STA)时间同步误差最小化问题;最后,提出基于经验匹配的电力物联网精准时间同步算法,通过调整时间同步匹配成本,优化STA的时间同步路径选择策略。仿真结果表明,所提方法能有效提高时间同步精度。
