An optimal decentralized control approach for damping of inter-area oscillations in power systems with a guaranteed level of damping is suggested in this paper. Widearea signals are used to supplement the actions of local controllers to improve the damping of the overall system. To guarantee a well-damped transient response, poles of the closedloop system are required to be in a prescribed regi...

We consider a shape optimization problem of finding the optimal damping set of a two-dimensional membrane such that the energy of the membrane is minimized at some fixed end time. Traditional shape optimization is based on sensitivities of the cost functional with respect to small boundary variations of the shapes. We use an iterative shape optimization scheme based on level set methods and the...

In this paper we treat the case of an abstract vibrational system of the form Mẍ + Cẋ + x = 0, where the positive semi-definite selfadjoint operators M and C commute. We explicitly calculate the solution of the corresponding Lyapunov equation which enables us to obtain the set of optimal damping operators, thus extending already known results in the matrix case.

Ambient operation poses a challenge to atomic force microscopy because in contrast to operation in vacuum or liquid environments, the cantilever dynamics change dramatically from oscillating in air to oscillating in a hydration layer when probing the sample. We demonstrate atomic resolution by imaging of the KBr(001) surface in ambient conditions by frequency-modulation atomic force microscopy ...

In this paper, the advantage of an adaptive damping system is presented. A damper with variable stiffness is tuned based on estimates of the real-time frequency response, facilitating optimal vibration mitigation. The performance of the developed routines is investigated on an existing tied arch railway bridge. Based on previous field measurements, resonant behaviour of several hangers was foun...

We consider a mathematical model of a linear vibrational system described by the second-order system of differential equations Mẍ +Dẋ+Kx = 0, where M, K and D are positive definite matrices, called mass, stiffness and damping, respectively. We are interested in finding an optimal damping matrix which will damp a certain part of the undamped eigenfrequencies. For this we use a minimization crite...

A numerical technique, composed of the Van Leer-Tai-Powell optimization and a modified procedure, is applied to design multistage schemes that give optimal damping of high frequencies for given upwind-biased spatial differencing with implicit and explicit residual smoothing. The analysis is done for a scalar convection equation in one space dimension. The object of this technique is to make the...

We define quantum-correlating power (QCP) of a local quantum channel acting on the left part of a bipartite quantum system as the maximum amount of left quantum correlation that can be created by this channel. We prove that for any local channel, the optimal input state, which corresponds to the maximum quantum correlation in the output state, must be a classical-classical state. Further, the s...

An optimal procedure for designing coordinated output feedback damping controllers of power system stabilizer (PSS) and STATCOM is developed for achieving and enhancing dynamic stability in single-machine infinite-bus power system. The coordinated design problem of STATCOM and PSS with output feedback controllers over a wide range of loading conditions is formulated as an optimization problem w...