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161.
El Kebir Boukas Peng Shi Sing Kiong Nguang 《Journal of Mathematical Analysis and Applications》2003,282(1):241-255
This paper studies the problem of stochastic stability and disturbance attenuation for a class of linear continuous-time uncertain systems with Markovian jumping parameters. The uncertainties are assumed to be nonlinear and state, control and external disturbance dependent. A sufficient condition is provided to solve the above problem. An H∞ controller is designed such that the resulting closed-loop system is stochastically stable and has a disturbance attenuation γ for all admissible uncertainties. It is shown that the control law is in terms of the solutions of a set of coupled Riccati inequalities. A numerical example is included to demonstrate the potential of the proposed technique. 相似文献
162.
工业污染排放中气──固两相流的光学测量 总被引:1,自引:0,他引:1
烟尘及各种工业性粉尘排放是典型的气-固两相系.迄今为止,国内外尚缺少有效的监测其排放的手段.本文基于光的散时原理,提出了一种非接触的光学方法,能对上述固体颗粒物的污染排放浓度及粒径大小进行实时、在线的监测。计算机模拟和实验研究表明,该方法具有广阔的工业应用前景。 相似文献
163.
Hans van den Berg Michel Mandjes Rudesindo Núñez-Queija 《Operations Research Letters》2007,35(3):297-307
We study a processor-sharing model in which users choose between a high- and a low-priority service, based on their utility functions and prices charged by the service provider. The latter aims at revenue maximization. The model is motivated by file transmissions in data networks with distributed congestion control. 相似文献
164.
Frank Rutz Martin Koch Shilpa Khare Martin Moneke Heike Richter Uwe Ewert 《International Journal of Infrared and Millimeter Waves》2006,27(4):547-556
We report on experiments that evaluate the potential of terahertz (THz) time-domain spectroscopy (TDS) for quality control
of polymeric compounds. We investigate specimens out of a polyethylene compound with silver-coated titanium dioxide nanospheres
and a glass-fiber reinforced epoxy composite. We further examine an industrial polymer product produced by injection molding.
Our data demonstrates that THz imaging is a powerful tool for contactless quality control in the polymer industry. 相似文献
165.
A class of long-range predictive adaptive fuzzy relational controllers is presented. The plant behavior is described over an extended time horizon by a fuzzy relational model which is identified based on input-output closed-loop observations of the plant variables. In this class of adaptive controllers the control law attempts to minimize a quadratic cost over an extended control horizon. When used with linear models, this approach has revealed a significant potential for overcoming the limitations of one-step ahead schemes, such as the stabilization of non-minimum phase plants. Here, a uniform framework is adopted for implementing both the fuzzy model and the fuzzy controller, namely distributed fuzzy relational structures gaining from their massive parallel processing features and from the learning capabilities typical of the connectivist approaches. Issues such as maintenance during the adaptation process of the meaning of linguistic terms used at both fuzzy systems interfaces are addressed, namely by introducing a new design methodology for on-line fuzzy systems interface adaptation. The examples presented reinforce the claim of the usefulness of this new approach. 相似文献
166.
The solvability of a class of forward-backward stochastic differential equations (SDEs for short) over an arbitrarily prescribed time duration is studied. The authors design a stochastic relaxed control problem, with both drift and difftusion all being controlled, so that the solvability problem is converted to a problem of finding the nodal set of the viscosity solution to a certain Hamilton-Jacobi-Bellman equation. This method overcomes the fatal difficulty encountered in the traditional contraction mapping approach to the existence theorem of such SDEs. 相似文献
167.
一、引 言 利用垂直场反馈控制等离子体位移是所有托卡马克装置运行的重要组成部分。对于中小型的托卡马克装置,人们曾倾向于用大功率晶闸管作反馈系统的调节器。它所遇到的主要困难有:第一需要有一个较大功率的中频电源。无论是中频发电机或者是逆变器都需要有较大的投资。另一方面受到中频电源的频率及晶闸管的关断时间的限制使反馈系统的时间响 相似文献
168.
169.
Linear propagation of two pulses through methanol solution of aluminum phthalocyanine chloride is investigated using a modified white-light Michelson interferometer. The observed coherence time of the white light is 6 fs, and the separation between the two-excitation pulses is set to about 10 fs. The excitation is dependent on the phase-relation between the two pulses. We have observed an enhancement of the excitation when the two pulses are in-phase and strong suppression of the excitation when the two pulses are out of phase by π. 相似文献
170.
Manicka Dhanasekar Jianjun Han Qinghua Qin 《Finite Elements in Analysis and Design》2006,42(14-15):1314-1323
Much work on special elements that simplify geometrical modelling of structures containing holes, cracks and/ or inclusions has been reported extensively in the literature. This paper presents a hybrid-Trefftz element containing elliptic hole formulated using Hellinger–Reissner principle by employing trial functions based on the mapping technique and the Cauchy integral method. The element presented in this paper could be regarded as an improved formulation over Piltner [Special finite elements with holes and internal cracks, Int. J. Numer. Methods Eng. 21 (1985) 1471–1485] element because the chosen trail functions in this paper have provided relatively more stable solutions. The use of the element with other ordinary displacement-based finite elements has also yielded very accurate solutions even when very coarse meshes relative to the size of the elliptic hole have been used. 相似文献