Utilization of STEP AP 210 at The Boeing Company

Boeing has been working on the development and implementation of STEP AP 210 since its inception. Using a combination of internally funded activities, external government contracts and multi-company pilots, Boeing has developed prototype tools to utilize AP 210 and is poised to move these tools into production. This paper begins with a brief overview of STEP and AP 210. The status of available AP 210 vendor translators (data generators), along with viewers and analysis programs (data consumers) is covered. Discussion continues with present and planned usage of AP 210 in several companies with the primary emphasis on implementation at The Boeing Company. The document concludes with a summary of key points.     

狗经氡子体暴露后血、毛中~(210)Pb 和~(210)Po 含量的动态变化

本文叙述了实验狗经氡子体暴露后血、毛中~(210)Po、~(210)Pb 含量、~(210)po/~(210)Pb 比率及血中~(210)Po,~(210)Pb 排出的动态变化。     

SFG and DFG investigation of Au(111), Au(210), polycrystalline Au,Au–Cu and Au–Ag–Cu electrodes in contact with aqueous solutions containing KCN and 4-cyanopyridine

We report on potential-dependent in situ SFG and DFG spectroscopy carried out at Au(111), Au(210), polycrystalline Au, Au–Cu and Au–Ag–Cu electrodes in contact with aqueous solutions containing CN⁻ and 4-cyanopyridine (4CP). Spectroelectrochemical work was complemented by cyclic voltammetry. The chief stress has been placed on systematising and quantifying the interaction between 4CP and CN⁻ and the attending effects on the vibrational and electronic structures of the interface. The voltammetric behaviour of the investigated electrodes, modified by the addition of 4CP to the CN⁻ electrolyte, denote changes in the CN⁻ adsorption characteristics and effects of the adsorbed CN⁻ layer on the electrodic reactivity of 4CP. The differences among the investigated electrodes can be explained in terms of their respective degrees of atomic packing or with alloying effects on the stability of adsorbed CN⁻. The potential-dependent spectra have been analysed quantitatively with a model for the second order non linear susceptibility accounting for vibrational and electronic effects. The spectral changes induced by addition of 4CP denote interaction of the aromatic with the electrode through the CN⁻ monolayer. The non-resonant contribution yields information on the effects of 4CP on the fine structure of the bound electron density of states.     

Gain‐scheduled dynamic output feedback control for discrete‐time LPV systems

This paper presents synthesis conditions for the design of gain‐scheduled dynamic output feedback controllers for discrete‐time linear parameter‐varying systems. The state‐space matrix representation of the plant and of the controller can have a homogeneous polynomial dependency of arbitrary degree on the scheduling parameter. As an immediate extension, conditions for the synthesis of a multiobjective ??_∞ and ??₂ gain‐scheduled dynamic feedback controller are also provided. The scheduling parameters vary inside a polytope and are assumed to be a priori unknown, but measured in real‐time. If bounds on the rate of parameter variation are known, they can be taken into account, providing less conservative results. The geometric properties of the uncertainty domain are exploited to derive finite sets of linear matrix inequalities based on the existence of a homogeneous polynomially parameter‐dependent Lyapunov function. An application of the control design to a realistic engineering problem illustrates the benefits of the proposed approach. Copyright © 2011 John Wiley & Sons, Ltd.     

Robust ℋ︁∞ PID control for multivariable networked control systems with disturbance/noise attenuation

In this paper, we study the design problem of PID controllers for networked control systems (NCSs) with polyhedral uncertainties. The load disturbance and measurement noise are both taken into account in the modeling to better reflect the practical scenario. By using a novel technique, the design problem of PID controllers is converted into a design problem of output feedback controllers. Our goal of this paper is two‐fold: (1) To design the robust PID tracking controllers for practical models; (2) To develop the robust ??_∞ PID control such that load and reference disturbances can be attenuated with a prescribed level. Sufficient conditions are derived by employing advanced techniques for achieving delay dependence. The proposed controller can be readily designed based on iterative suboptimal algorithms. Finally, four examples are presented to show the effectiveness of the proposed methods. Copyright © 2011 John Wiley & Sons, Ltd.     

A new design of delay‐dependent robust ℋ︁∞ filtering for continuous‐time polytopic systems with time‐varying delay

This paper revisits the problem of delay‐dependent robust ?_∞ filtering design for a class of continuous‐time polytopic linear systems with a time‐varying state delay. Based on a newly developed parameter‐dependent Lyapunov–Krasovskii functional combined with Projection Lemma and an improved free‐weighting matrix technique for delay‐dependent criteria, a new sufficient condition for robust ?_∞ performance analysis is first derived and then the filter synthesis is developed by using a simple matrix inequality linearization technique. It is shown that the desired filters can be constructed by solving a set of linear matrix inequalities. Finally, two simulation examples are given to show the effectiveness and less conservatism of the proposed method in comparison with the existing approaches. Copyright © 2009 John Wiley & Sons, Ltd.     

COMPLEX AND REAL PERFORMANCE RADII AND THEIR COMPUTATION

This paper considers the problem of robust performance of a linear time-invariant system in the ℋ︁_∞ norm. The concepts of complex and real performance radii are introduced to describe the smallest size of dynamic or parametric perturbations to a feedback system that either destabilize the system or destroy a performance bound in a certain closed-loop transfer matrix of the system. An algorithm to compute the complex performance radius is given. For the real performance radius, a lower bound, which often turns out to be exact, is obtained. © 1997 by John Wiley & Sons, Ltd.     

Robust performance analysis for uncertain negative‐imaginary systems

Negative‐imaginary systems are important in engineering practice as this class of systems appears quite often in practical problems, for example, lightly damped flexible structures with collocated position sensors and force actuators. In this paper, an analytical framework for robust performance of uncertain negative‐imaginary systems is proposed. The results are obtained by transforming negative‐imaginary systems into a bounded‐real framework via the positive‐real property. This paper deals with all the significant technical difficulties that appear due to the transformation and the punctured j ω‐axis frequency condition of negative‐imaginary systems. The problem is equivalently cast into a structured singular value condition that gives a quantitative performance test for this class of systems. This result also gives an analytical framework for robust stability when the perturbations are mixture of bounded‐real and negative‐imaginary uncertainties. A numerical example is presented to show the usefulness of the proposed methods. Copyright © 2011 John Wiley & Sons, Ltd.     

基于Cortex-A8的数据采集监控系统设计

该文介绍了一种采用单总线数字式的温度传感器DS18B20与S5PV210芯片组成的新型温度监控系统,系统以S5PV210芯片为控制核心,利用新型一线制温度传感器DS18B20测量温度值,实现环境温度的检测和监控。该设计以温度采集为例,详细描述了基于Cortex-A8的数据采集监控系统的硬件结构与软件实现。     

内螺纹管内部缺陷分析

电厂在对管屏用测厚仪测厚时发现内螺纹管局部壁厚不足,取样解剖,通过着色发现在管子横断面上有很细的长条缺陷,现场判断为分层。实际是,电厂测厚的结果大部分是由于测厚仪与管子间偶合的不好,个别点是由于内螺纹管内部有小缺陷导致测厚减薄。经金相试验,结果表明缺陷是夹杂物。