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A frequency analysis has been conducted to study vibration energy harvesting performance and characteristics of a single degree of freedom vibration energy harvester connected to a single load resistor based on the Laplace transfer method and physical models of a voltage source. The performance and characteristics of electromagnetic and piezoelectric harvesters have been analysed and compared. The main research outcome is the disclosure of similarity and duality of electromagnetic and piezoelectric harvesters for both the energy harvesting efficiency and the normalised resonant harvested power using only two dimensionless characteristic parameters: the normalised resistance and the normalised force factor. The dimensionless resonant harvested power and energy harvesting efficiency analysis allows for a parameter study and optimization of the ambient vibration energy harvesters from macro- to nano-scales and for evaluation of the vibration energy harvester performance regardless of the size and type. [ABSTRACT FROM AUTHOR]

Abstract: This paper is concerned with robust integral sliding mode control for an offshore steel jacket platforms subject to nonlinear wave-induced force and parameter perturbations. A robust integral sliding mode controller is designed to stabilize the dynamic model of the offshore steel jacket platform. It is shown through simulation results that the robust integral sliding mode control scheme can reduce the internal oscillations of the offshore steel jacket platform dramatically; and the performance of the offshore steel jacket platform under the robust integral sliding mode control scheme is better than the ones under the nonlinear control scheme and the dynamic output feedback control scheme. [Copyright &y& Elsevier]