期刊文献+
共找到5篇文章
< 1 >
每页显示 20 50 100
玉米品种(系)间遗传距离计算中几个问题的探讨
1
作者 杨文鹏 王伟 《贵州农业科学》 CAS 北大核心 2013年第12期1-3,共3页
主要探讨了半正定阵和不定阵用于计算品种(系)间遗传距离的可行性,以及在试验中如何避免计算产生零、负特征根,保证以正定实对称矩阵进入计算的问题;同时,阐明了表-主-遗-欧法(PGD法)的优越性。经理论和实用性分析,得出以下结论:半正定... 主要探讨了半正定阵和不定阵用于计算品种(系)间遗传距离的可行性,以及在试验中如何避免计算产生零、负特征根,保证以正定实对称矩阵进入计算的问题;同时,阐明了表-主-遗-欧法(PGD法)的优越性。经理论和实用性分析,得出以下结论:半正定阵或不定阵可用于计算品种(系)间遗传距离;在计算品种(系)间距离时,应具有较大样本,并且宜采用较少和非高度线性相关的性状;PGD法由于考虑了各性状的遗传力,计算的遗传距离能真实地反映品种(系)间的遗传差异。 展开更多
关键词 遗传距离 线性相关 半正定 不定阵 大样本 玉米 植物
在线阅读 下载PDF
一种求任意埃尔米特广义特征值的方法
2
作者 征道生 徐兰 《华东师范大学学报(自然科学版)》 CAS CSCD 1993年第3期34-43,共10页
本文利用五种复变换矩阵(其中四种为作者新提出),给出一种求解埃尔米特广义特征值问题Ax=λBx的方法,这里A,B为n阶任意埃尔米特阵.可说是[1]和[2]中方法的改进与推广,[1]中讨论了A、B实对称B非奇异的情形,[2]中的MDR法只能用于A,B实对称... 本文利用五种复变换矩阵(其中四种为作者新提出),给出一种求解埃尔米特广义特征值问题Ax=λBx的方法,这里A,B为n阶任意埃尔米特阵.可说是[1]和[2]中方法的改进与推广,[1]中讨论了A、B实对称B非奇异的情形,[2]中的MDR法只能用于A,B实对称B半正定的情形.它们都不能解决B为奇异且不定的情形,也不能解决A,B为埃尔米特的情形.本文还对[1]中的中断情况作了改进,对MDR方法的改进在别处讨论,新方法称CHR法. 展开更多
关键词 不定埃米特 广义特征值 CHR法
在线阅读 下载PDF
Decentralized H_∞ state feedback control for large-scale interconnected uncertain systems with multiple delays 被引量:2
3
作者 陈宁 桂卫华 谢永芳 《Journal of Central South University of Technology》 EI 2004年第1期93-97,共5页
Decentralized H_∞ control was studied for a class of interconnected uncertain systems with multiple delays in the state and control and time varying but norm-bounded parametric uncertainties. A sufficient condition w... Decentralized H_∞ control was studied for a class of interconnected uncertain systems with multiple delays in the state and control and time varying but norm-bounded parametric uncertainties. A sufficient condition which makes the closed-loop system decentralized asymptotically stable with H_∞ performance was derived based on Lyapunov stability theorem. This condition is expressed as the solvability problem of linear matrix inequalities. The method overcomes the limitations of the existing algebraic Riccati equation method. Finally, a numerical example was given to demonstrate the design procedure for the decentralized H_∞ state feedback controller. 展开更多
关键词 UNCERTAINTY TIME-DELAY linear matrix inequality decentralized H_∞ control
在线阅读 下载PDF
Error code analysis and selection principle of M-ary modulation in network-based control systems
4
作者 赵顺利 尹逊和 +1 位作者 魏学业 H. K. LAM 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第6期1372-1382,共11页
Error codes induced by M-ary modulation and modulation selection in network-based control systems are studied.It is the first time the issue of error codes induced by M-ary modulation is addressed in control field.In ... Error codes induced by M-ary modulation and modulation selection in network-based control systems are studied.It is the first time the issue of error codes induced by M-ary modulation is addressed in control field.In network-based control systems,error codes induced by noisy channel can significantly decrease the quality of control.To solve this problem,the network-based control system with delay and noisy channel is firstly modeled as an asynchronous dynamic system(ADS).Secondly,conditions of packet with error codes(PEC)loss rate by using M-ary modulation are obtained based on dynamic output feedback scheme.Thirdly,more importantly,the selection principle of M-ary modulation is proposed according to the measured signal-to-noise ratio(SNR)and conditions of PEC loss rate.Finally,system stability is analyzed and controller is designed through Lyapunov function and linear matrix inequality(LMI)scheme,and numerical simulations are made to demonstrate the effectiveness of the proposed scheme. 展开更多
关键词 network-based control system asynchronous dynamic system (ADS) M-ary modulation delay error code linear matrix inequality (LMI)
在线阅读 下载PDF
Design of observer-based discrete repetitive-control system based on 2D model
5
作者 王昭鸿 易灵芝 +1 位作者 兰永红 陈才学 《Journal of Central South University》 SCIE EI CAS 2014年第11期4236-4243,共8页
A discrete observer-based repetitive control(RC) design method for a linear system with uncertainties was presented based on two-dimensional(2D) system theory. Firstly, a 2D discrete model was established to describe ... A discrete observer-based repetitive control(RC) design method for a linear system with uncertainties was presented based on two-dimensional(2D) system theory. Firstly, a 2D discrete model was established to describe both the control behavior within a repetition period and the learning process taking place between periods. Next, by converting the designing problem of repetitive controller into one of the feedback gains of reconstructed variables, the stable condition was obtained through linear matrix inequality(LMI) and also the gain coefficient of repetitive system. Numerical simulation shows an exceptional feasibility of this proposal with remarkable robustness and tracking speed. 展开更多
关键词 state observer two-dimensional discrete system repetitive control linear matrix inequality
在线阅读 下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部