该文在奇异值矩阵分解方法的基础上,提出了一种融合景点季节演变信息的旅游推荐算法。该算法根据景点属性与季节演变之间的关联,将旅游景点的属性划分为静态方面和动态方面,并通过设计包含时间因素的动态偏置函数来刻画用户偏好与景点...该文在奇异值矩阵分解方法的基础上,提出了一种融合景点季节演变信息的旅游推荐算法。该算法根据景点属性与季节演变之间的关联,将旅游景点的属性划分为静态方面和动态方面,并通过设计包含时间因素的动态偏置函数来刻画用户偏好与景点之间的动态关联。这些静态和动态方面的信息被作为新的偏置项融入有偏奇异分解(Bias singular value decomposition,Bias SVD)模型,以改善用户对旅游景点的评分预测。标准数据集Yelp上的实验结果表明,相比于对用户签到数据无差别对待的推荐方法,该文方法在推荐精度和用户体验方面均有明显的提升。展开更多
针对锁相环同步的弱连接电压源变流器(weakgrid connected voltage source converter,WG-VSC)系统的暂态稳定问题,该文首先应用线性矩阵不等式优化法构建WG-VSC系统的最大估计吸引域(largest estimated domain of attraction,LEDA),并将...针对锁相环同步的弱连接电压源变流器(weakgrid connected voltage source converter,WG-VSC)系统的暂态稳定问题,该文首先应用线性矩阵不等式优化法构建WG-VSC系统的最大估计吸引域(largest estimated domain of attraction,LEDA),并将LEDA与基于LaSalle不变集定理的能量函数法和平方和规划法构建的LEDA进行详细对比,验证了所提方法在刻画LEDA方面具有更低的保守性。然后从保证故障穿越控制过程中的锁相环暂态同步稳定作为切入点,首次提出WG-VSC系统在电网对称故障大扰动下的有功/无功电流设定值可行域概念,并基于线性矩阵不等式方法刻画的LEDA,提出该可行域的求解算法,分析了典型参数对该电流设定值可行域的影响。该可行域为故障过程中的有功和无功电流设定值提供了切实可行的指导依据。最后在PSCAD/EMTDC中搭建了基于详细开关模型的WG-VSC系统仿真算例,通过多种暂态仿真工况验证了该文所构建的LEDA和电流设定值可行域的有效性和可行性。展开更多
The aim of this paper is to study the determination of the stability regions for continuous-time systems subject to actuator saturation. Using an affine saturation-dependent Lyapunov function, a new method is proposed...The aim of this paper is to study the determination of the stability regions for continuous-time systems subject to actuator saturation. Using an affine saturation-dependent Lyapunov function, a new method is proposed to obtain the estimation of the domain of attraction of the closed-loop system. A family of linear matrix inequalities （LMIs） that provides sufficient conditions for the existence of this type of Lyapunov function are presented. The results obtained in this paper can reduce the conservativeness compared with the existing ones. Numerical examples are given to illustrate the effectiveness of the proposed results.展开更多
Both time-delays and anti-windup(AW)problems are conventional problems in system design,which are scarcely discussed in cellular neural networks(CNNs).This paper discusses stabilization for a class of distributed time...Both time-delays and anti-windup(AW)problems are conventional problems in system design,which are scarcely discussed in cellular neural networks(CNNs).This paper discusses stabilization for a class of distributed time-delayed CNNs with input saturation.Based on the Lyapunov theory and the Schur complement principle,a bilinear matrix inequality(BMI)criterion is designed to stabilize the system with input saturation.By matrix congruent transformation,the BMI control criterion can be changed into linear matrix inequality(LMI)criterion,then it can be easily solved by the computer.It is a one-step AW strategy that the feedback compensator and the AW compensator can be determined simultaneously.The attraction domain and its optimization are also discussed.The structure of CNNs with both constant timedelays and distribute time-delays is more general.This method is simple and systematic,allowing dealing with a large class of such systems whose excitation satisfies the Lipschitz condition.The simulation results verify the effectiveness and feasibility of the proposed method.展开更多
文摘该文在奇异值矩阵分解方法的基础上,提出了一种融合景点季节演变信息的旅游推荐算法。该算法根据景点属性与季节演变之间的关联,将旅游景点的属性划分为静态方面和动态方面,并通过设计包含时间因素的动态偏置函数来刻画用户偏好与景点之间的动态关联。这些静态和动态方面的信息被作为新的偏置项融入有偏奇异分解(Bias singular value decomposition,Bias SVD)模型,以改善用户对旅游景点的评分预测。标准数据集Yelp上的实验结果表明,相比于对用户签到数据无差别对待的推荐方法,该文方法在推荐精度和用户体验方面均有明显的提升。
基金Supported by the grants from the National Natural Science Foundation of China(61004043)the Specialized Research Fund for the Doctoral Program of Higher Education(2009092120066)
文摘针对锁相环同步的弱连接电压源变流器(weakgrid connected voltage source converter,WG-VSC)系统的暂态稳定问题,该文首先应用线性矩阵不等式优化法构建WG-VSC系统的最大估计吸引域(largest estimated domain of attraction,LEDA),并将LEDA与基于LaSalle不变集定理的能量函数法和平方和规划法构建的LEDA进行详细对比,验证了所提方法在刻画LEDA方面具有更低的保守性。然后从保证故障穿越控制过程中的锁相环暂态同步稳定作为切入点,首次提出WG-VSC系统在电网对称故障大扰动下的有功/无功电流设定值可行域概念,并基于线性矩阵不等式方法刻画的LEDA,提出该可行域的求解算法,分析了典型参数对该电流设定值可行域的影响。该可行域为故障过程中的有功和无功电流设定值提供了切实可行的指导依据。最后在PSCAD/EMTDC中搭建了基于详细开关模型的WG-VSC系统仿真算例,通过多种暂态仿真工况验证了该文所构建的LEDA和电流设定值可行域的有效性和可行性。
基金supported by the National Creative Research Groups Science Foundation of China (No.60721062)the National High Technology Research and Development Program of China (863 Program) (No.2006AA04 Z182)National Natural Science Foundation of China (No.60736021)
文摘The aim of this paper is to study the determination of the stability regions for continuous-time systems subject to actuator saturation. Using an affine saturation-dependent Lyapunov function, a new method is proposed to obtain the estimation of the domain of attraction of the closed-loop system. A family of linear matrix inequalities （LMIs） that provides sufficient conditions for the existence of this type of Lyapunov function are presented. The results obtained in this paper can reduce the conservativeness compared with the existing ones. Numerical examples are given to illustrate the effectiveness of the proposed results.
基金supported by the National Natural Science Foundation of China(61374003 41631072)the Academic Foundation of Naval University of Engineering(20161475)
文摘Both time-delays and anti-windup(AW)problems are conventional problems in system design,which are scarcely discussed in cellular neural networks(CNNs).This paper discusses stabilization for a class of distributed time-delayed CNNs with input saturation.Based on the Lyapunov theory and the Schur complement principle,a bilinear matrix inequality(BMI)criterion is designed to stabilize the system with input saturation.By matrix congruent transformation,the BMI control criterion can be changed into linear matrix inequality(LMI)criterion,then it can be easily solved by the computer.It is a one-step AW strategy that the feedback compensator and the AW compensator can be determined simultaneously.The attraction domain and its optimization are also discussed.The structure of CNNs with both constant timedelays and distribute time-delays is more general.This method is simple and systematic,allowing dealing with a large class of such systems whose excitation satisfies the Lipschitz condition.The simulation results verify the effectiveness and feasibility of the proposed method.
