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—In this paper, the design of controllers that incorporate structural and multiobjective performance requirements is considered. The control structures under study cover nested, chained, hierarchical, delayed interaction and communications, and symmetric systems. Such structures are strongly related to several modern-day and future applications including(More)
— Lur'e systems represent feedback interconnections of a Linear Time-Invariant system with a nonlinear operator. The Zames-Falb criterion is a powerful tool to determine the stability of a Lur'e system when the nonlinear operator is defined by a monotonic, odd and single-valued function. The article provides a generalization of the Zames-Falb criterion for(More)
—Several methods have been developed for joint working and spare capacity planning in survivable wavelength-division -multiplexing (WDM) networks. These methods have considered a static traffic demand and optimized the network cost assuming various cost models and survivability paradigms. Our interest primarily lies in network operation under dynamic(More)
In this paper, we consider two important objectives of network operation: (i) capacity minimization and (ii) revenue maximization. For capacity minimization, we formulate three operational phases in sur-vivable WDM network operation viz., initial call set up, short/medium-term reconfiguration, and long-term reconfiguration. All three phases are derived from(More)
In this paper, we study the dynamical behavior of a microcantilever-sample system that forms the basis for the operation of atomic force microscopes (AFM). We model the microcantilever by a single mode approximation and the interaction between the sample and cantilever by a van der Waals (vdW) potential. The cantilever is vibrated by a sinusoidal input, and(More)
Hysteresis and constitutive nonlinearities are inherent properties of ferroelectric transducer materials due to the noncentrosymmetric nature of the compounds. In certain regimes, these effects can be mitigated through restricted input fields, charge-or current-controlled amplifiers, or feedback designs. For general operating conditions, however, these(More)
In this paper, we develop nonlinear constitutive equations and resulting system models quantifying the nonlinear and hysteretic field-displacement relations inherent to lead zirconate titanate (PZT) devices employed in atomic force microscope stage mechanisms. We focus specifically on PZT rods utilizing d 33 motion and PZT shells driven in d 31 regimes, but(More)
—In this paper, a method to synthesize controllers that achieve globally optimal robust performance within any prespec-ified tolerance, against structured norm-bounded time-varying and/or nonlinear uncertainty is developed. The performance measure considered is the infinity to infinity induced norm of a system's transfer function. The method developed(More)