This study takes Lin'an City which early carries out the experiment of ecological operation of hickory as the study site.On the basis of the input-output data on hickory and farmers' land,we analyze the input-...This study takes Lin'an City which early carries out the experiment of ecological operation of hickory as the study site.On the basis of the input-output data on hickory and farmers' land,we analyze the input-output status of hickory land which practises ecological operation,the operators' willingness to accept ecological operation and the influencing factors.The results show that in the short term,ecological operation of hickory will have a certain negative impact on the economic benefits;within the experimental area,the degree of operators' willingness to accept ecological operation of hickory is high,and the operators have a clear understanding of long-term comprehensive benefits which may be brought by ecological operation;the ecological experiment and demonstration of hickory have achieved certain results;family income level,characteristics of householders,education and training,and so on,are the main factors that affect the operators' willingness to choose ecological operation.Finally,for how to further improve the promotion efficiency of ecological operation of hickory,we put forth some constructive recommendations.展开更多
针对防空作战中现有多功能雷达功率资源利用率低的问题,提出一种基于服务质量(Quanlity of Service,QoS)模型的三维机动跟踪功率分配方法以差异化标准提升多目标跟踪性能。将目标三维机动模型建立为自适应当前统计模型,通过将加速度协...针对防空作战中现有多功能雷达功率资源利用率低的问题,提出一种基于服务质量(Quanlity of Service,QoS)模型的三维机动跟踪功率分配方法以差异化标准提升多目标跟踪性能。将目标三维机动模型建立为自适应当前统计模型,通过将加速度协方差与估计误差协方差矩阵相关联以实现自适应调整。在此基础上,对三维跟踪下的贝叶斯克拉美罗下界进行推导,并将其作为跟踪误差衡量指标。通过构建关于目标威胁度与期望跟踪精度的函数关系,建立防空QoS模型下的闭环功率优化分配机制。证明所构建功率优化分配模型是凸优化问题,并进一步转化为半正定规划问题进行求解。仿真结果表明,相对于传统功率分配方法,所提方法能显著提高全局跟踪效能。展开更多
以基于演算子理论的鲁棒右互质分解(Operator-based robust right coprime factorization,RRCF)为基础,提出了一种较新的非线性鲁棒控制方法.本文将简述此方法的概念、基本理论及其应用.具体地说,本文首先介绍此方法的起源与基本概念;然...以基于演算子理论的鲁棒右互质分解(Operator-based robust right coprime factorization,RRCF)为基础,提出了一种较新的非线性鲁棒控制方法.本文将简述此方法的概念、基本理论及其应用.具体地说,本文首先介绍此方法的起源与基本概念;然后,讨论此方法在系统的鲁棒稳定性、输出跟踪与故障检测方面的设计等问题;最后,介绍此方法的实际应用从而进一步证明其有效性.展开更多
基金Supported by Zhejiang Provincial Natural Science Foundation(Y6090002)Talent Initiation Project of Zhejiang Agriculture and Forestry University (2011FR001)Scientific Research Innovation Fund Project of Zhejiang Agriculture and Forestry University(2112010015)
文摘This study takes Lin'an City which early carries out the experiment of ecological operation of hickory as the study site.On the basis of the input-output data on hickory and farmers' land,we analyze the input-output status of hickory land which practises ecological operation,the operators' willingness to accept ecological operation and the influencing factors.The results show that in the short term,ecological operation of hickory will have a certain negative impact on the economic benefits;within the experimental area,the degree of operators' willingness to accept ecological operation of hickory is high,and the operators have a clear understanding of long-term comprehensive benefits which may be brought by ecological operation;the ecological experiment and demonstration of hickory have achieved certain results;family income level,characteristics of householders,education and training,and so on,are the main factors that affect the operators' willingness to choose ecological operation.Finally,for how to further improve the promotion efficiency of ecological operation of hickory,we put forth some constructive recommendations.
文摘针对防空作战中现有多功能雷达功率资源利用率低的问题,提出一种基于服务质量(Quanlity of Service,QoS)模型的三维机动跟踪功率分配方法以差异化标准提升多目标跟踪性能。将目标三维机动模型建立为自适应当前统计模型,通过将加速度协方差与估计误差协方差矩阵相关联以实现自适应调整。在此基础上,对三维跟踪下的贝叶斯克拉美罗下界进行推导,并将其作为跟踪误差衡量指标。通过构建关于目标威胁度与期望跟踪精度的函数关系,建立防空QoS模型下的闭环功率优化分配机制。证明所构建功率优化分配模型是凸优化问题,并进一步转化为半正定规划问题进行求解。仿真结果表明,相对于传统功率分配方法,所提方法能显著提高全局跟踪效能。
文摘现有工程运行数据显示,并网变流器(grid-connected converter,GCC)的动态特性与工作点密切相关。受新能源出力波动、负载投切等外部因素的影响,变流器工作点呈现随机时变特性。因此,分析整个工作区间中所有工作点的系统稳定性具有重要意义。传统阻抗/导纳分析方法可以有效分析GCC运行于特定工作点时的稳定性,但考虑系统所有可能工作点时则需重复分析,工作量大且难度较高。为解决这一难题,提出一种考虑工作点变量的多元建模方法。将工作点变量引入导纳模型,通过控制环路重构,建立GCC的多变量单输入单输出(single input single output,SISO)模型。所提模型直接包含工作点变量,因此可以有效分析变流器全工作区间动态特性。此外,综合考虑变流器最大传输限制和动态特性,提出一种基于安全运行域的稳定性分析方法,以实现多维工作区间中系统稳定性的直观表征。仿真和实验验证了所提多变量SISO模型和基于安全运行域的分析方法的正确性。所提模型和方法在分析电力电子装置运行极限、指导变流器设计和辅助功率器件发挥极限性能等工程场景中具有广泛应用潜力。
文摘以基于演算子理论的鲁棒右互质分解(Operator-based robust right coprime factorization,RRCF)为基础,提出了一种较新的非线性鲁棒控制方法.本文将简述此方法的概念、基本理论及其应用.具体地说,本文首先介绍此方法的起源与基本概念;然后,讨论此方法在系统的鲁棒稳定性、输出跟踪与故障检测方面的设计等问题;最后,介绍此方法的实际应用从而进一步证明其有效性.
