Abstract-In this paper we present a method for the addition of integral action to non-passive outputs of a class of portHamiltonian systems. The proposed integral controller is a dynamic extension, constructed from the open loop system, such that the closed loop preserves the port-Hamiltonian form. It is shown that the controller is able to reject the effects of both matched and unmatched disturbances, preserving the regulation of the non-passive outputs. Previous solutions to this problem have relied on a change of coordinates whereas the presented solution is developed using the original state vector and, therefore, retains its physical interpretation. In addition, the resulting closed loop dynamics have a natural interpretation as a Control by Interconnection scheme.

In this paper we present a new result on rejection of unmatched external disturbances on port-Hamiltonian systems using Control by Interconnection (CbI). The PHS structure is used to design a controller that rejects unmatched constant disturbances from non-passive outputs. In the PHS framework, the disturbance rejection problem has been addressed adding integral action and using a change of coordinates. In our approach, we avoid a change of coordinates keeping the original state vector, which contains variables with physical interpretation. The methodology proposed in this paper is illustrated on an electrical circuit and on a permanent magnet synchronous motor. Simulation of the later example shows the performance of the control design.

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Applied economists have investigated individual adoption choices as well as diffusion (aggregate adoption). The emphasis, however, has been on adopters' behavior and risk associated with production and markets. Marketing also considers broader aspects and marketers develop tools to address risk related to the fit of a product, its performance, and its reliability. This paper expands the economic literature on adoption by analyzing and assessing the implications of the choice of marketing tools, like money‐back guarantees, demonstrations, and others, by marketers. The analysis is based on the threshold model of diffusion, which recognizes heterogeneity and dynamics. We provide evidence and examples from agriculture.

In this letter, we consider the problem of regulating the voltage of an islanded Direct Current (DC) network subject to (i) unknown ZIP-loads, i.e., nonlinear loads with the parallel combination of constant impedance (Z), current (I) and power (P) components, and (ii) unknown time-varying disturbances. Using the port-Hamiltonian framework, two decentralized passivity-based control schemes are designed. It is shown that, using the proposed controllers, the desired equilibrium is exponentially stable and local input-to-state stable (LISS) with respect to unknown time-varying disturbances.