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1.
考虑了一类关联大系统的可靠控制器设计问题,该系统具有常时滞、参数不确定性和传感器故障.其中参数不确定性满足匹配条件,传感器具有部分失效的模型.目的是设计无记忆分散控制器来镇定该系统.通过解线性矩阵不等式获得此控制器,使得当传感器器发生故障时被控系统能够保持渐近稳定.最后通过仿真的例子,验证该状态反馈控制器的可行性.  相似文献   

2.
研究了一类具有参数不确定性的关联模糊大系统的保性能控制问题,基于线性矩阵不等式(LMI)方法给出了该不确定性模糊大系统分散状态反馈保性能控制器的设计方案,所设计的分散状态反馈保性能控制器不但使得该不确定性模糊大系统闭环渐近稳定,而且使得其二次型性能指标的上界最小.最后通过一个数值例子说明了所提出方法的有效性.  相似文献   

3.
考虑参数不确定性对一类宏观经济系统的影响,研究了宏观经济系统的鲁棒控制问题,给出系统的鲁棒控制律以及经济系统鲁棒稳定的条件,鲁棒控制律保证了宏观经济系统稳定的运行,同时可以使国民产总值在短时间内跟踪总需求,通过仿真验证了该算法的有效性.  相似文献   

4.
线性不确定大系统的分散变结构控制   总被引:2,自引:2,他引:0  
本研究了具有参数摄动、关联影响和外界干扰等不确定因素影响的线性大系统的分散控制问题。在假设系统不确定性有界且满足一定匹配条件的前提下,给出了系统的一种分散变结构控制算法,实现了大系统的全局渐近稳定。该控制律设计简单,并保证了闭环系统较好的动态性能和较强的鲁棒性。  相似文献   

5.
基于李雅普诺夫函数法,提出了一种适用于不确定性线性大系统的分散鲁棒稳定控制方法.系统的不确定性因素包括系统参数摄动、关联变化以及外界干扰.由于实际大系统的不确定因素复杂且系统关联变化很难描述,因而在控制律中又引入了对设计参数的自适应算法,大大简化了控制器的设计和实现.所提出的控制律可以保证系统在不确定性干扰和关联变化的情况下全局稳定,同时自适应算法使参数收敛.仿真结果表明了该控制方法的有效性  相似文献   

6.
考虑了一类参数不确定广义互联大系统的分散鲁棒镇定问题,所考虑的不确定参数满足范数有界条件,利用LMI方法,给出了保证闭环系统鲁棒稳定的充分条件,最后用数值算例说明该方法简单有效.  相似文献   

7.
本文针对具有强结构不确定性的时滞关联大系统,通过构造适当的Lyapunov函数,并利用M矩阵的性质,给出了系统时滞无关的鲁棒稳定充分条件。并通过一个算验证例了所得结果。  相似文献   

8.
基于状态观测器,给出了具有参数摄动、关联影响和外界干扰等不确定因素影响的线性组合大系统的一种分散变结构控制器的设计方法,该控制器设计简单并能保证闭环大系统的全局渐近稳定.  相似文献   

9.
针对一类多平衡态非线性系统,考虑系统具有范数有界时变参数不确定性,存在执行器故障时的绝对稳定控制问题.对于Lur’e型多平衡态非线性系统,基于将Leonov的频域判据转化为H∞次优问题,考虑系统具有范数有界时变参数不确定性,且系统的执行器出现故障时,采用动态输出反馈控制,给出系统鲁棒容错控制器存在性问题的判据,进一步给出了基于LM I(线性矩阵不等式)的鲁棒控制器的设计方法.仿真表明了该方法的有效性.  相似文献   

10.
研究δ算子描述的线性不确定时滞系统的可靠保性能控制问题.考虑系统含有参数范数有界不确定性和连续模型执行器故障,根据Lyapunov稳定性理论,给出对于所有允许的不确定性和执行器故障,均使闭环系统渐近稳定且给定性能指标具有一定上界的状态反馈控制器的存在条件,由此提出相应控制器的设计方法.通过数值算例验证了设计方法的可行性.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

14.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

15.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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