基于观测器的广义系统H_∞可靠性控制器

利用广义系统的传感器故障模型,研究广义系统H∞可靠性控制器的设计问题·首先,建立了广义系统传感器故障的一般模型,在此模型的基础上设计基于观测器的控制器·其次,定义了广义系统的H∞可靠性控制器·接着,用带广义约束的广义代数Riccati不等式(GARI),给出传感器正常及出现部分故障时,所设计的控制器使得闭环广义系统容许且传递函数H∞范数有界的充分条件,即存在H∞可靠性控制器的充分条件·同时,还通过对广义系统的受限等价变换,去掉了广义约束,简化了带广义约束的GARI·进而可以通过解简化后的GARI来设计H∞可靠性控制器·最后,给出一个数值例子来演示设计过程并说明此方法的有效性·     

广义非线性交联大系统的鲁棒模糊分散控制

利用广义T S模糊模型对广义非线性交联大系统进行了鲁棒控制研究·首先 ,对广义非线性交联大系统建立模糊模型·然后 ,在系统可解条件下 ,给出了模糊分散控制器的设计方法 ,分析其考虑建模误差时的鲁棒稳定性 ,给出基于LMI的闭环系统鲁棒稳定的充分条件·进而 ,应用模糊规则及权重的性质得到基于LMI优化技术的低保守性的鲁棒模糊分散控制器设计方法·最后 ,算例说明了控制器的设计步骤和有效性·     

具有强不确定性大系统的H_∞分散控制器设计

具有强不确定性的组合大系统控制难点在于其互联项对子系统的强大干扰·针对这个问题,提出了一种H∞分散控制器设计方法·将控制器的设计归结为解一组局部代数Riccati方程·不确定项可分成两部分:结构部分和有界部分·结构部分的不确定性界可以是任意大的,并且是可以不满足匹配条件的·所设计的控制器由两部分组成,保证具有强互联不确定性的组合系统是具有干扰衰减指数γ的分散可稳的·为了克服解Riccati方程的困难,LMI方法被用于分散控制器的设计·     

一类复杂非线性系统的模糊控制稳定性分析

研究一类能够用离散动态模糊模型描述的复杂非线性系统的模糊控制稳定性问题·首先设计出PDC模糊控制器·然后利用区间系统理论,在带扰动系统二次稳定意义下给出了闭环系统渐近稳定的两个充分条件,并且后一稳定性条件被转化为线性矩阵不等式可解性问题·仿真结果证明了此方法的有效性·     

基于多模型切换的多变量直接自适应控制器

当系统参数发生跳变时,为了解决系统暂态响应变差的问题,提出一种基于多模型切换的多变量直接自适应控制器·该控制器由多个参数已知的固定模型和2个自适应模型构成,多个固定参数控制器模型可由系统参数模型通过映射直接得到,并且和邻域一起完全覆盖控制器参数模型集·不但消除了稳态误差,而且实现了解耦控制·最后给出全局收敛性分析·仿真结果表明暂态响应和解耦效果得到了提高·     

TCSC的非线性逆推设计

针对带有TCSC(ThyristorControlledSeriesCompensation)的单机无穷大总线系统的非线性二阶模型,使用逆推方法设计了TCSC的非线性控制器·基于逆推设计方法,无需对原系统进行线性化,并能保证闭环误差系统在Lyapunov意义下渐近稳定·当系统存在常参数不确定性,例如阻尼系数不能精确测量的情况下,应用自适应逆推方法还可以设计一个动态反馈控制器,其中含有对未知参数的实时估计·设计过程表明逆推方法设计的控制器拥有更优越的性能·     

砼小型空心砌块砌体的非线性动力分析有限元模型

提出了一个研究平面动荷下(地震荷载)砼小型空心砌块砌体动力反应的非线性分析模型·并将其导入非线性动力分析有限元程序·将砌块砌体看作为一种非线性均质正交异性材料,提出了破坏包络线,可用于预测灰缝的滑移和开裂,及压碎类型破坏·并通过一个统一灰缝模型来考虑了水平灰缝的方向性效应·非线性动力分析利用修正NewtonRaphson迭代和Newmark时间积分来完成·通过非线性动力分析和试验验证,证明了该模型的有效性·该模型可以用于动力时程分析·     

具有周期系数的单种群模型的最优脉冲控制

最优脉冲捕获意味着被开发资源种群密度的突然变化和获取相对高的利润·种群的这一动态行为可由脉冲微分方程和某一性能指标来描述·从建模开始,得出了所研究模型的满足初值条件解的表达式及它的渐近稳定性定理·在此基础上,通过建立适当的性能指标,对周期脉冲系统进行了最优控制,得到了所研究模型的最优捕获效果和相应的最优捕获量·文章的结果既保证了资源管理者可以得到相对高的利润,也能使种群持续生存下去·     

基于动态神经网络的一类非线性组合系统自适应控制

针对一类非线性组合大系统,提出一种用动态神经网络逼近组合大系统的新型设计方法·首先由动态神经网络辨识非线性组合大系统,也就是利用动态神经网络逼近系统的未知项和互联项,其次设计控制器使实际系统的状态来跟踪参考模型的轨迹·利用Lyapunov稳定性理论保证跟踪误差和其他信号是最终一致有界的·通过一个非线性系统例子的仿真证明这种设计方法的可行性·这种设计方法能够解决大系统中最为复杂的互联项问题,得出基于神经网络的自适应控制律·     

线性不确定时滞系统的时滞相关H~∞控制

基于动态耗散理论和微分对策理论,研究了确定性和不确定性线性时滞系统的时滞相关H∞状态反馈控制器的设计问题·将鲁棒控制器设计问题转化为非合作对策中目标函数求解鞍点问题,并针对确定性和不确定性线性时滞系统分别得到了控制器存在的充分条件·对于不确定线性时滞系统可以通过求解线性矩阵不等式进行时滞相关H∞鲁棒控制器设计,使系统内稳且具有H∞干扰衰减系数λ·而对于确定性线性时滞系统仅需要验证一个线性矩阵不等式,使设计问题得以简化·     

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.     

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.     

A computer generator for randomly layered structures

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

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.