We propose multi-periodic nanostructures yielded by superposition of multiple binary gratings for wide control over photon emission in thin-film devices. We present wavelength- and angle-resolved photoluminescence measurements of multi-periodically nanostructured organic light-emitting layers. The spectral resonances are determined by the periodicities of the individual gratings. By varying com...

We present an approach to the design of feedback control laws that stabilize relative equilibria of general nonlinear systems with continuous symmetry. Using a template-based method, we factor out the dynamics associated with the symmetry variables and obtain evolution equations in a reduced frame that evolves in the symmetry direction. The relative equilibria of the original systems are fixed ...

Delays in feedback control loop, as induced by networked distributed control schemes, may have detrimental effects on control performance. This induces an interest in safety verification of delay differential equations (DDEs) used as a model of embedded control. This article explores reachable-set computation for a class of DDEs featuring a local homeomorphism property. This topological propert...

This paper proposes an active noise control algorithm for periodic disturbances of unknown frequency. The algorithm is appropriate for the feedback case in which a single error microphone is used. A previously proposed algorithm for the rejection of sinusoidal noise sources is extended for the cancellation of multiple harmonics. Unlike many other approaches, the estimates of the frequencies of ...

The stabilization of periodic control systems using time scales is studied. Time scale is a model of time. The language of time scales seems to be an ideal tool to unify the continuous-time and the discrete-time theories. In this work we suggest an alternative way to solve stabilization problems. This method is based on a combination of the Lyapunov functions method with local controllability c...

In this paper a recursive control theoretic smoothing spline approach is proposed for reconstructing a closed contour. Periodic splines are generated through minimizing a cost function subject to constraints imposed by a linear control system. The optimal control problem is shown to be proper and sufficient optimality conditions are derived for a special case of the problem using Hamilton-Jacob...

EEorts on the numerical approximation and simulation of control of time periodic parabolic distributed parameter system are reported. Test examples have been chosen suc that the optimal control can be explicitly computed via analytical methods. The approximation framework and convergence theory are applied to a polynomial spline based approximation scheme. In the case of control of one dimensio...

Chaotic attractors of discrete-time neural networks include infinitely many unstable periodic orbits, which can be stabilized by small parameter changes in a feedback control. Here we explore the control of unstable periodic orbits in a chaotic neural network with only two neurons. Analytically, a local control algorithm is derived on the basis of least squares minimization of the future deviat...

It is demonstrated that improved entrainment control of chaotic systems can maintain periodic goal dynamics near unstable periodic orbits without feedback. The method is based on the optimization of goal trajectories and leads to small open-loop control forces.

Chaotic attractors of discrete-time neural networks include innnitely many unstable periodic orbits, which can be stabilized by small parameter changes in a feedback control. Here we explore the control of unstable periodic orbits in a chaotic neural network with only two neurons. Analytically a local control algorithm is derived on the basis of least squares minimization of the future deviatio...