To improve the security of the smart grid, quantum key distribution（QKD） is an excellent choice. The rapid fluctuations on the power aerial optical cable and electromagnetic disturbance in substations are two main c...To improve the security of the smart grid, quantum key distribution（QKD） is an excellent choice. The rapid fluctuations on the power aerial optical cable and electromagnetic disturbance in substations are two main challenges for implementation of QKD. Due to insensitivity to birefringence of the channel, the stable phase-coding Faraday–Michelson QKD system is very practical in the smart grid. However, the electromagnetic disturbance in substations on this practical QKD system should be considered. The disturbance might change the rotation angle of the Faraday mirror, and would introduce an additional quantum bit error rate（QBER）. We derive the new fringe visibility of the system and the additional QBER from the electromagnetic disturbance. In the worst case, the average additional QBER only increases about 0.17% due to the disturbance, which is relatively small to normal QBER values. We also find the way to degrade the electromagnetic disturbance on the QKD system.展开更多
为提高固态变压器逆变级的性能,实现系统自动寻优,解决各种负载扰动时暂态稳定性问题,提出了一种基于线性扩张状态观测器LESO(linear extended state observer)估计误差补偿的改进二阶线性自抗扰单环控制策略,并引入模糊自适应与改进线...为提高固态变压器逆变级的性能,实现系统自动寻优,解决各种负载扰动时暂态稳定性问题,提出了一种基于线性扩张状态观测器LESO(linear extended state observer)估计误差补偿的改进二阶线性自抗扰单环控制策略,并引入模糊自适应与改进线性自抗扰中的状态误差反馈控制率结合,使用Lyapunov稳定性定义证明了系统的稳定性。最后,利用MATLAB/Simulink仿真平台对固态变压器逆变级进行建模,对文中提出的策略在各种工况下的控制性能进行了测试,验证了其正确性和参考价值。展开更多
The main purpose of this paper is to give an extension on learning with errors problem (LWE) based cryptosystem about the probability of decryption error with more general disturbance. In the first section, we introdu...The main purpose of this paper is to give an extension on learning with errors problem (LWE) based cryptosystem about the probability of decryption error with more general disturbance. In the first section, we introduce the LWE cryptosystem with its application and some previous research results. Then we give a more precise estimation probability of decryption error based on independent identical Gaussian disturbances and any general independent identical disturbances. This upper bound probability could be closed to 0 if we choose applicable parameters. It means that the probability of decryption error for the cryptosystem could be sufficiently small. So we verify our core result that the LWE-based cryptosystem could have high security.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61101137,61201239,61205118,and 11304397)the National Basic Research Program of China(Grants No.2013CB338002)
文摘To improve the security of the smart grid, quantum key distribution（QKD） is an excellent choice. The rapid fluctuations on the power aerial optical cable and electromagnetic disturbance in substations are two main challenges for implementation of QKD. Due to insensitivity to birefringence of the channel, the stable phase-coding Faraday–Michelson QKD system is very practical in the smart grid. However, the electromagnetic disturbance in substations on this practical QKD system should be considered. The disturbance might change the rotation angle of the Faraday mirror, and would introduce an additional quantum bit error rate（QBER）. We derive the new fringe visibility of the system and the additional QBER from the electromagnetic disturbance. In the worst case, the average additional QBER only increases about 0.17% due to the disturbance, which is relatively small to normal QBER values. We also find the way to degrade the electromagnetic disturbance on the QKD system.
文摘为提高固态变压器逆变级的性能,实现系统自动寻优,解决各种负载扰动时暂态稳定性问题,提出了一种基于线性扩张状态观测器LESO(linear extended state observer)估计误差补偿的改进二阶线性自抗扰单环控制策略,并引入模糊自适应与改进线性自抗扰中的状态误差反馈控制率结合,使用Lyapunov稳定性定义证明了系统的稳定性。最后,利用MATLAB/Simulink仿真平台对固态变压器逆变级进行建模,对文中提出的策略在各种工况下的控制性能进行了测试,验证了其正确性和参考价值。
文摘The main purpose of this paper is to give an extension on learning with errors problem (LWE) based cryptosystem about the probability of decryption error with more general disturbance. In the first section, we introduce the LWE cryptosystem with its application and some previous research results. Then we give a more precise estimation probability of decryption error based on independent identical Gaussian disturbances and any general independent identical disturbances. This upper bound probability could be closed to 0 if we choose applicable parameters. It means that the probability of decryption error for the cryptosystem could be sufficiently small. So we verify our core result that the LWE-based cryptosystem could have high security.
