An input-output signal selection based on Phillips-Heffron model of a parallel high voltage alternative current/high voltage direct current(HVAC/HVDC) power system is presented to study power system stability. It is w...An input-output signal selection based on Phillips-Heffron model of a parallel high voltage alternative current/high voltage direct current(HVAC/HVDC) power system is presented to study power system stability. It is well known that appropriate coupling of inputs-outputs signals in the multivariable HVDC-HVAC system can improve the performance of designed supplemetary controller. In this work, different analysis techniques are used to measure controllability and observability of electromechanical oscillation mode. Also inputs–outputs interactions are considered and suggestions are drawn to select the best signal pair through the system inputs-outputs. In addition, a supplementary online adaptive controller for nonlinear HVDC to damp low frequency oscillations in a weakly connected system is proposed. The results obtained using MATLAB software show that the best output-input for damping controller design is rotor speed deviation as out put and phase angle of rectifier as in put. Also response of system equipped with adaptive damping controller based on HVDC system has appropriate performance when it is faced with faults and disturbance.展开更多
An adaptive approach to select analysis window param- eters for linear frequency modulated （LFM） signals is proposed to obtain the optimal 3 dB signal-to-noise ratio （SNR） in the short- time Fourier transform （S...An adaptive approach to select analysis window param- eters for linear frequency modulated （LFM） signals is proposed to obtain the optimal 3 dB signal-to-noise ratio （SNR） in the short- time Fourier transform （STFT） domain. After analyzing the instan- taneous frequency and instantaneous bandwidth to deduce the relation between the window length and deviation of the Gaus- sian window, high-order statistics is used to select the appropriate window length for STFT and get the optimal SNR with the right time-frequency resolution according to the signal characteristic under a fixed sampling rate. Computer simulations have verified the effectiveness of the new method.展开更多
【目的】对金定鸭与台湾褐色菜鸭进行选择信号分析,挖掘这2个蛋鸭品种在长期进化过程中受到强烈选择的重要经济性状相关候选基因,为揭示优异性状形成的遗传差异奠定基础。【方法】选取金定鸭和台湾褐色菜鸭各30只进行全基因组重测序,经...【目的】对金定鸭与台湾褐色菜鸭进行选择信号分析,挖掘这2个蛋鸭品种在长期进化过程中受到强烈选择的重要经济性状相关候选基因,为揭示优异性状形成的遗传差异奠定基础。【方法】选取金定鸭和台湾褐色菜鸭各30只进行全基因组重测序,经过滤获取高质量单核苷酸多态性位点(SNPs)后,对其进行主成分分析(PCA),确定其遗传分化情况;然后采用群体遗传分化指数(Fst)和群体核酸多样性比值(πratio)2种方法综合筛选金定鸭和台湾褐色菜鸭的受选择信号,分析其遗传差异。【结果】金定鸭和台湾褐色菜鸭重测序分别获得5.68和5.59 Gb高质量数据,分别检测到152238286和155009562个SNPs,其SNP位点分布相似。主成分分析结果显示,金定鸭和台湾褐色菜鸭显著分化;以100 kb为窗口、10 kb为步长分别计算Fst与πratio值,将Fst top 5%(Fst>0.482)与πratio top 5%&bottom 5%(0<πratio≤0.47&πratio≥3.00)作为信号重叠区域,共注释到208个候选基因。对这208个候选基因进行GO与KEGG富集分析,发现金定鸭在免疫、脂质代谢、肌肉生长发育等方面受到更强烈的选择,筛选到IL15、CCL3、CD180、AKT1、PPARGC1A、PRKAA1、FASN、PIK3R1等功能基因。【结论】金定鸭和台湾褐色菜鸭显著分化,金定鸭在免疫、脂质代谢、肌肉生长发育等方面受到强烈选择。展开更多
针对在信号交叉口前由于车辆转向和换道操作频繁容易引发冲突、降低通行效率的问题,构建基于深度强化学习(DQN)的车辆群体控制模型,优化车辆车道选择.首先,利用传感器和网联设备等获取周围车辆及交叉口信号灯实时状态信息,基于共享DQN...针对在信号交叉口前由于车辆转向和换道操作频繁容易引发冲突、降低通行效率的问题,构建基于深度强化学习(DQN)的车辆群体控制模型,优化车辆车道选择.首先,利用传感器和网联设备等获取周围车辆及交叉口信号灯实时状态信息,基于共享DQN模型进行车道选择,并根据该结果计算下一时刻位置、速度和转向角;进一步以效率及安全性指标建立奖励函数对车道选择决策实施评价,将状态信息、决策信息及奖励评价信息整合形成经验,存入同一经验池用于共享DQN模型参数迭代更新;最后,使用SUMO(simulation of urban mobility)与Python联合仿真搭建不同交通流量环境对训练后的模型进行验证.研究表明:相较于SUMO中的车道选择模型,基于共享DQN模型的信号交叉口前车辆群体车道选择模型,在低、中、高流量测试场景的平均速度均有提高,交叉口前排队长度分别减少了9.6%、22.5%和24.8%.本文模型可以有效减少信号交叉口的排队长度、提高信号交叉口前的路段平均速度、增强车辆从上游到达交叉口的效率,为未来车路协同的应用提供理论借鉴和技术支持.展开更多
文摘An input-output signal selection based on Phillips-Heffron model of a parallel high voltage alternative current/high voltage direct current(HVAC/HVDC) power system is presented to study power system stability. It is well known that appropriate coupling of inputs-outputs signals in the multivariable HVDC-HVAC system can improve the performance of designed supplemetary controller. In this work, different analysis techniques are used to measure controllability and observability of electromechanical oscillation mode. Also inputs–outputs interactions are considered and suggestions are drawn to select the best signal pair through the system inputs-outputs. In addition, a supplementary online adaptive controller for nonlinear HVDC to damp low frequency oscillations in a weakly connected system is proposed. The results obtained using MATLAB software show that the best output-input for damping controller design is rotor speed deviation as out put and phase angle of rectifier as in put. Also response of system equipped with adaptive damping controller based on HVDC system has appropriate performance when it is faced with faults and disturbance.
基金supported by the National Natural Science Foundation of China(6107313361175053+8 种基金6127236960975019)the Heilongjiang Postdoctoral Grant(LRB08362)the Fundamental Research Funds for the Central Universities of China(2011QN0272011QN1262012QN0302011ZD010)the Science and Technology Planning Project of Dalian City(2011A17GX0732010E15SF153)
文摘An adaptive approach to select analysis window param- eters for linear frequency modulated （LFM） signals is proposed to obtain the optimal 3 dB signal-to-noise ratio （SNR） in the short- time Fourier transform （STFT） domain. After analyzing the instan- taneous frequency and instantaneous bandwidth to deduce the relation between the window length and deviation of the Gaus- sian window, high-order statistics is used to select the appropriate window length for STFT and get the optimal SNR with the right time-frequency resolution according to the signal characteristic under a fixed sampling rate. Computer simulations have verified the effectiveness of the new method.
文摘【目的】对金定鸭与台湾褐色菜鸭进行选择信号分析,挖掘这2个蛋鸭品种在长期进化过程中受到强烈选择的重要经济性状相关候选基因,为揭示优异性状形成的遗传差异奠定基础。【方法】选取金定鸭和台湾褐色菜鸭各30只进行全基因组重测序,经过滤获取高质量单核苷酸多态性位点(SNPs)后,对其进行主成分分析(PCA),确定其遗传分化情况;然后采用群体遗传分化指数(Fst)和群体核酸多样性比值(πratio)2种方法综合筛选金定鸭和台湾褐色菜鸭的受选择信号,分析其遗传差异。【结果】金定鸭和台湾褐色菜鸭重测序分别获得5.68和5.59 Gb高质量数据,分别检测到152238286和155009562个SNPs,其SNP位点分布相似。主成分分析结果显示,金定鸭和台湾褐色菜鸭显著分化;以100 kb为窗口、10 kb为步长分别计算Fst与πratio值,将Fst top 5%(Fst>0.482)与πratio top 5%&bottom 5%(0<πratio≤0.47&πratio≥3.00)作为信号重叠区域,共注释到208个候选基因。对这208个候选基因进行GO与KEGG富集分析,发现金定鸭在免疫、脂质代谢、肌肉生长发育等方面受到更强烈的选择,筛选到IL15、CCL3、CD180、AKT1、PPARGC1A、PRKAA1、FASN、PIK3R1等功能基因。【结论】金定鸭和台湾褐色菜鸭显著分化,金定鸭在免疫、脂质代谢、肌肉生长发育等方面受到强烈选择。
文摘针对在信号交叉口前由于车辆转向和换道操作频繁容易引发冲突、降低通行效率的问题,构建基于深度强化学习(DQN)的车辆群体控制模型,优化车辆车道选择.首先,利用传感器和网联设备等获取周围车辆及交叉口信号灯实时状态信息,基于共享DQN模型进行车道选择,并根据该结果计算下一时刻位置、速度和转向角;进一步以效率及安全性指标建立奖励函数对车道选择决策实施评价,将状态信息、决策信息及奖励评价信息整合形成经验,存入同一经验池用于共享DQN模型参数迭代更新;最后,使用SUMO(simulation of urban mobility)与Python联合仿真搭建不同交通流量环境对训练后的模型进行验证.研究表明:相较于SUMO中的车道选择模型,基于共享DQN模型的信号交叉口前车辆群体车道选择模型,在低、中、高流量测试场景的平均速度均有提高,交叉口前排队长度分别减少了9.6%、22.5%和24.8%.本文模型可以有效减少信号交叉口的排队长度、提高信号交叉口前的路段平均速度、增强车辆从上游到达交叉口的效率,为未来车路协同的应用提供理论借鉴和技术支持.
