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1.
This paper focuses on the fault estimation problem for switched systems with partially unknown nonlinear dynamics, actuator and sensor faults, simultaneously. The fault estimation observers are constructed, in which the observer dimension is not fixed and can be selected in a certain range. Both the disturbance decoupling and disturbance attenuation are considered, where the unknown nonlinear dynamics can be decoupled and the effect of modeling error and measurement disturbance is attenuated. Based on the average dwell time and the piecewise Lyapunov function, the observer parameter matrices can be calculated by solving LMIs and matrix equations. Finally, two examples are listed to verify the proposed fault estimation approach. 相似文献
2.
《Applied Mathematical Modelling》2014,38(9-10):2601-2612
This study devotes to incorporating a nonmonotone strategy with an automatically adjusted trust-region radius to propose a more efficient hybrid of trust-region approaches for unconstrained optimization. The primary objective of the paper is to introduce a more relaxed trust-region approach based on a novel extension in trust-region ratio and radius. The next aim is to employ stronger nonmonotone strategies, i.e. bigger trust-region ratios, far from the optimizer and weaker nonmonotone strategies, i.e. smaller trust-region ratios, close to the optimizer. The global convergence to first-order stationary points as well as the local superlinear and quadratic convergence rates are also proved under some reasonable conditions. Some preliminary numerical results and comparisons are also reported. 相似文献
3.
电流变液与电-磁流变液的衍射特性 总被引:5,自引:3,他引:2
本文把电流变液装置作为反射光栅研究其衍射特性,首次提出由电场强度改变来调节光栅常数的概念.并讨论了同时外加电场与磁场的情况下,电磁流变液的衍射特性. 相似文献
4.
首先用溶胶-凝胶法制备符合SrAl2O4:Eu^2 ,Dy^3 化学组成的溶胶,然后通过机械研磨、水热反应和微波加热反应三种不同的组装方法和微波还原扩散法使其进入主体ZSM-5沸石的孔道中。主客体材料的荧光光谱出现显著蓝移,余辉光谱出现400nm和517nm两个发射峰,两个余辉峰的相对发射强度随组装方法和组装浓度的改变而具有可调性,呈现有规律的变化。分析其原因是由于发光材料进入沸石的纳米级孔洞引起的。 相似文献
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调整光谱仪的光谱分辨率,可使光谱仪在满足不同目标测量需求的同时,减少数据采集、处理和存储的时间,提高仪器的整体性能。为克服传统傅里叶变换光谱仪的光谱分辨率固定的缺点,提出了一种分辨率可调的空间调制傅里叶变换光谱仪。介绍了该新型光谱仪及其干涉仪的工作原理,利用光线追迹的方法推导了光程差和横向剪切量的计算公式,并分析了新型干涉仪的光程等效模型。在此基础上,分析了光谱分辨率的调节原理。结果表明,该光谱分辨率可调的新型空间调制傅里叶变换光谱仪克服了传统光谱仪分辨率固定、稳定性差等缺点,具有分辨率可调、高稳定性、结构灵活和易于装调等特点。该研究内容为分辨率可调的干涉光谱仪的设计提供了理论基础,扩展了傅里叶变换光谱仪的实用范围。 相似文献
7.
Carole M. Dean Christian Ahmarani Maurice Bettez Reinhardt J. Heuer 《Journal of voice》2001,15(1):141-150
An adjustable laryngeal implant made of titanium has been developed for the treatment of unilateral vocal fold paralysis. The implant includes three parts: a plate that allows fixation to the thyroid cartilage, a block of titanium which includes the adjustable part, and a micrometric screw in the middle of the lateral side of the block, which moves the adjustable part. Precise medialization is accomplished by regulating the screw which also permits easy secondary adjustments, if needed in the future. This retrospective study assesses clinical outcomes of medialization laryngoplasty with the titanium adjustable implant, in patients with unilateral vocal fold paralysis. This study has the limitations of a retrospective study. However, preliminary results are encouraging. Analysis of subjective responses confirmed marked improvement in laryngeal function, speech, and swallowing. Objective voice analysis confirmed improvement in the aerodynamic measures. The adjustable laryngeal implant has many advantages including: precise medialization, ease of secondary adjustment, and preseveration of the mucosal wave. This implant is biocompatible, no migration is possible (it is fixed to the cartilage) and no extrusion of the implant has occurred. Titanium is magnetic resonance imaging (MRI)-safe. 相似文献
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This paper presents an approximate affinely adjustable robust counterpart for conic quadratic constraints. The theory is applied
to obtain robust solutions to the problems of subway route design with implementation errors and a supply chain management
with uncertain demands. Comparison of the adjustable solutions with the nominal and non-adjustable robust solutions shows
that the adjustable (dynamic) robust solution maintains feasibility for all possible realizations, while being less conservative
than the usual (static) robust counterpart solution. 相似文献
9.
Alexander Shapiro 《Operations Research Letters》2011,39(2):83-87
In this paper we consider the adjustable robust approach to multistage optimization, for which we derive dynamic programming equations. We also discuss this from the point of view of risk averse stochastic programming. We consider as an example a robust formulation of the classical inventory model and show that, like for the risk neutral case, a basestock policy is optimal. 相似文献
10.
在Glauber理论的基础上,考虑到原子内部的电子运动对于象e-H的弹性和非弹性散射截面计算的影响。理论计算表明,原子内部电子的运动对于e-H的弹性散射截面影不大,而对于非弹性散射截面有着一定的影响。 相似文献