共查询到20条相似文献，搜索用时 460 毫秒
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王其红 《职教通讯(江苏技术师范学院学报)》2007,13(4)
研究了时滞广义系统的稳定与镇定问题.利用广义二次稳定和广义二次镇定的概念,应用线性矩阵不等式方法分别给出了时滞广义系统广义二次稳定和广义二次镇定的充要条件,它们都是一严格的线性矩阵不等式,同时给出了相应的控制器表达式.最后,举例说明了给出方法的应用. 相似文献
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为了克服数据量化、网络诱导时滞、网络丢包及错序对非线性网络控制系统造成的影响,采用T-S模糊建模方法建立了一个新的非线性网络控制系统模型,并在系统模型中加入2个时变量化器.主要分析方法在于通过构造一个改进的区间时滞依赖的李雅普诺夫函数,并引入自由权矩阵.利用并行分布式补偿技术和矩阵函数的凸性,得出了改进系统的稳定和镇定的条件.仿真实验表明,通过求解一组线性矩阵不等式,可得保证系统渐近稳定并满足一定性能的控制器参数和量化器参数.在具有非线性的弹簧系统中的应用验证了所提方法的有效性. 相似文献
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苏亚坤 《临沂师范学院学报》2007,29(3):10-14
研究输入中含有时滞的系统的鲁棒镇定问题和H∞鲁棒控制.闭环系统的结论最终是以线性矩阵不等式的形式给出的.列举的例子说明文中所提出的方法具有更小的保守性,而且所设计出来的控制器也具有较小的反馈增益. 相似文献
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针对一类同时具有状态时滞和输入时滞的时变不确定连续时滞系统,研究了保成本状态反馈控制器的设计,假定其中的时变不确定性项是范数有界的,但不需要满足匹配条件,通过构造改造的Lyapunov函数和线性矩阵不等式(LMI)方法.给出了系统满足保性能指标的一个充分条件,仅通过求解一个相应的线性矩阵不等式,就可得到保性能控制器使得闭环系统的一个保成本函数对所有允许的不确定参数有上界.通过求解凸优化问题得到最优保性能控制器,最后用示例说明了该方法的有效性. 相似文献
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本文主要对一类带有时变状态滞后的离散系统的镇定问题进行研究．给出了该类系统的输出反馈镇定控制器存在的充分条件。进一步将结果推广到不确定系统．给出了鲁棒镇定控制器存在的充分条件. 相似文献
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本文主要对一类带有时变状态滞后的离散系统的镇定问题进行研究,给出了该类系统的输出反馈镇定控制器存在的充分条件.进一步将结果推广到不确定系统,给出了鲁棒镇定控制器存在的充分条件. 相似文献
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本文主要对一类带有时变：状态滞后的离散系统的镇定问题进行研究．给出了该类系统的输出反馈镇定控制器存在的充分条件。进一步将结果推广到不确定系统．给出了鲁棒镇定控制器存在的充分条件？ 相似文献
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针对一类具有时变状态时滞和参数不确定性的线性不确定时滞系统,研究了闭环极点具有α-稳定性限制的鲁棒H∞控制器设计问题.对所有容许的不确定,首先给出判断系统鲁棒α-稳定且具有干扰衰减γ的充分条件;而后基于线性矩阵不等式方法,分别提出了状态反馈和动态输出反馈控制器存在的充分条件及相应的控制器设计方法.数值算例验证了所给结果的有效性. 相似文献
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《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
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《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
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Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
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Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities. 相似文献
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RUZBEHANI Mohsen 《重庆大学学报(英文版)》2004,3(1):20-25
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec… 相似文献
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唐芳 《读与写:教育教学刊》2008,5(6)
During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context. 相似文献