基于集员估计的线性MIMO系统故障检测方法

考虑了一类具有未知有界噪声的线性多输入多输出(MIMO)系统的故障检测问题,提出了一种基于集员估计的故障检测方法.通过当前时刻系统状态范围和测量输出值的一致性检验来检测系统是否发生故障.如果系统正常运行,则利用系统测量输出信息校正当前时刻系统状态范围.利用三容水箱系统模型进行了仿真研究,结果表明了所提方法的有效性.     

基于高增益近似微分器的执行器故障重构

针对一类伴有外界干扰的线性系统,探讨了执行器故障重构的问题．首先,使用高增益近似微分器得到输出导数的估计值．然后,构建一种未知输入观测器,实现对外界干扰和执行器故障解耦,可以渐近跟踪系统的状态．基于状态和输出导数的估计值,使用代数方法可以直接重构系统的执行器故障．仿真结果表明,所提出的方法是有效的．     

一种基于鲁棒残差生成器的故障估计方法

针对具有加性执行器或元部件故障的线性系统,在独立故障的个数大于独立测量个数的情况下,提出了一种基于鲁棒残差生成器的故障估计方法.该故障估计方法是基于鲁棒残差生成器实现的,不需要额外设计动态的故障估计器.故障估计的实现需要:设计编码集;基于编码集设计鲁棒残差生成器;利用编码集和鲁棒残差生成器的输出实现故障分离和故障的渐近估计.给出了本方法的适用的充分条件,并证明了故障估计误差的渐近收敛性.最后,针对具有加性执行器故障的线性系统,基于几何方法设计鲁棒残差生成器,并进行了故障检测、故障分离和故障估计的仿真.仿真结果验证了本故障估计方法的有效性.     

基于RBF神经网络的非线性系统故障诊断

针对一类含模型不确定性的非线性系统,提出了具有强鲁棒性和高灵敏度的在线故障检测与诊断方法.其中,系统只有输入、输出可检测,故障是关于输入和状态的非线性函数.非线性在线估计器用于估计系统不确定部分,同时监视系统是否发生故障,估计故障的大小.仿真结果表明,故障诊断算法稳定.     

非线性系统执行器故障检测及重构

针对受到外部干扰的利布希茨非线性系统,讨论了一种观测器匹配条件不满足下的基于观测器的执行器故障检测方法.通过构造辅助输出,使得匹配条件针对该辅助输出得以满足;通过一高阶滑模观测器,不仅估计出辅助输出,还估计出它的微分.基于高阶滑模观测器,提出了一种执行器故障重构的方法.通过引入一个自适应调节项,对利布希茨常数进行自适应性调节,从而设计中无需知道利布希茨常数的大小.最后通过一个3阶系统的仿真,表明了方法的有效性.     

Lipschitz非线性系统未知输入观测器设计

针对观测器匹配条件不满足情况下的Lipschitz非线性系统状态估计和未知输入重构问题,提出了一种未知输入观测器设计方法.首先,通过构造辅助输出向量,突破了观测器匹配条件的限制,并设计高阶、高增益滑模微分器实现对辅助输出向量及其微分的精确估计;之后,在辅助输出及其微分精确估计的基础上,设计具有滑模控制律和自适应调节律的自适应鲁棒滑模观测器,并提出了一种未知输入重构方法.该观测器设计方法不需知道Lipschitz常数,其大小可通过自适应调节律调节,且信息重构具有避免直接使用系统输出微分的优点.仿真结果表明,所设计的未知输入观测器不仅在观测器匹配条件不满足情况下可以实现对状态的渐进估计以及对未知输入重构之目的,而且自适应调节律能够在约5 s时间内实现对Lipschitz常数的自适应调节.     

基于T-S模糊模型的观测器和动态输出反馈容错控制器设计

针对具有执行器故障和传感器故障的非线性系统,提出了一种基于T-S模型的观测器设计和动态输出反馈控制器设计方法。首先,将非线性系统转化为T-S模型,以此模型作为设计模型,利用扩展传感器故障为辅助状态向量的方式,将系统扩展为增维的T-S描述系统;然后,针对增维的T-S描述系统,设计模糊自适应观测器以达到对非线性系统的状态、执行器和传感器故障同时估计的目的;最后,基于观测器对传感器和执行器故障的估计,设计了一种动态输出反馈容错控制器以达到容错控制的目的,其中以线性矩阵不等式的方式给出了观测器和容错控制器存在的充分性条件。通过实例仿真验证了该文设计方法的有效性。     

故障估计的快速梯度算法

加性故障的估计通常是依赖于状态空间模型,如滑动时域估计和未知的输入观测器。本文基于闭环系统的输入-输出观测数据,采用直接设计的方法来估计故障,并设计控制器。该直接方法无需建立系统和故障的状态空间模型,也无需采用子空间辨识来建模。对于故障的估计,利用闭环系统中输入-输出关系建立一个参数化的最小二乘问题。在施加故障的上下限约束条件下,采用快速梯度算法来估计故障。最后以直升机悬停状态为例,利用本文方法估计故障,验证方法的有效性。     

基于多频H_∞最优观测器的航天器故障诊断

针对航天器姿态控制系统中的陀螺故障,利用控制输入信息,依据故障信号频率,使用LMI分别设计多组H∞最优故障观测器。该方法无需其他测量校验,能够克服传统诊断方法对星敏感器的依赖;同时扩展H∞观测器的设计自由度,降低惯量不确定性对系统诊断精度的影响。在Matlab/Simulink环境下对航天器姿态系统进行了仿真,仿真结果表明:提出的控制算法处理航天器陀螺故障问题的有效性和可行性。     

线性参数变化系统的鲁棒故障估计

针对仿射参数变化系统,研究了鲁棒H∞故障估计问题。基于增益调度的思想,提出了一种鲁棒H∞故障估计器设计方法,该方法所设计的故障估计器与对象具有相同的参数依赖性,而且可以通过线性矩阵不等式进行求解。文中通过实例展示了设计的全过程,仿真结果表明本文所给出的方法能够有效地处理一类参数变化系统的故障估计问题。     

Markedness and its Interpretation in Language Use

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Features of Women's language

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.     

On Tragic Consciousness In The Works By Ernest Hemingway

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.