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971.
1IntroductionElectronholographyhasnowbecomeapowerfultoolfordirectobservationofelectromagneticmicrofield,forthereasonthatcoher... 相似文献
972.
We study deterministic discounted optimal control problems associated with discrete-time systems. It is shown that, for small discount rates, the controllability properties of the underlying system can guarantee the convergence of the discounted value function to the value function of the average yield. An application in the theory of exponential growth rates of discrete inclusions is presented. This application motivates the analysis of infinite-horizon optimal control problems with running yields that are unbounded from below. 相似文献
973.
G. Ambrosino G. Celentano F. Garofalo 《Journal of Optimization Theory and Applications》1986,50(2):239-255
The development of flexible manufacturing systems calls for industrial robots characterized by robustness of performance with regard to the variations of the loads and real time specification of the trajectory in the work space. In this paper, the design of a feedback controller guaranteeing such performance is considered. At first, the manipulator dynamics are embedded into a larger class of uncertain dynamical systems and a class of feedback controls is proposed that guarantees uniform ultimate boundedness of the tracking error. Successively, the methodology is specialized for the case of robotic manipulators to track trajectories described in task-oriented coordinates; the proposed control algorithm operates without requiring any explicit coordinate transformation. 相似文献
974.
Qihong Chen 《Journal of Mathematical Analysis and Applications》2003,277(1):303-323
This paper is concerned with an optimal control problem for some semilinear evolutionary variational inequalities associated with bilateral constraints. The control domain is a general separable metric space and has no algebraic structure, in particular, it is not necessarily convex. Existence and optimality conditions of optimal pairs are established. 相似文献
975.
In this paper an important problem in chaos control theory concerningthe possibility of generating a new stable periodic solutionby a small feedback control law for a dynamical system is addressed.It is proved that a solution with an initial point being somekind of non-wandering property can become a new asymptoticallystable solution by a small feedback control law. This showsthat the popular opinion that a small control law is not ableto create a new periodic point is untrue, and suggests a newapproach to controlling chaos. 相似文献
976.
This paper is concerned with the simultaneous maneuver and vibration control of a flexible spacecraft. The problem is solved by means of a perturbation approach whereby the slewing of the spacecraft regarded as rigid represents the zero-order problem and the control of vibration, as well as of perturbations from the rigid-body maneuver, represents the first-order problem. The zero-order control is to be carried out in minimum time, which implies bang-bang control. On the other hand, the first-order control is a time-dependent linear quadratic regulator including integral feedback and prescribed convergence rate.This research was sponsored by USAF/ASD and AFOSR Research Grant F33615-86-C-3233 monitored by Drs. A. K. Amos and V. B. Venkayya, whose support is greatly appreciated. 相似文献
977.
978.
979.
G. Ortner M. Bayer A. Kress A. Forchel Y. B. Lyanda-Geller T. L. Reinecke 《Physica E: Low-dimensional Systems and Nanostructures》2004,21(2-4):171
Semiconductor nanostructures have attracted considerable interest during the recent years in view of the potential application in quantum information processing. In particular, quantum dots have been suggested to fulfill an essential requirement for quantum computation: controllable interaction that couples two quantum dot qubits. Previous experiments on two vertically aligned quantum dots have demonstrated the formation of coupled exciton states. We show that this coupling between two In0.60Ga0.40As/GaAs quantum dots can be tuned by an electric field applied along the molecule axis. This controllable coupling in such a relatively simple configuration could be implemented in a solid-state-based quantum device. 相似文献
980.
J. H. Park 《Journal of Optimization Theory and Applications》2005,124(2):491-502
In this article, the guaranteed cost control problem for a class of neutral delay systems is investigated. A linear--quadratic cost function is considered as a performance measure for the closed-loop system. Based on the Lyapunov method, delay-dependent criteria, which are expressed in terms of matrix inequalities, are proposed to guarantee the asymptotic stability of the system. The matrix inequalities can be solved easily by various efficient optimization algorithms. 相似文献