This paper proposes a Flexible Power Electronic Transformer (FPET) for the application in the micro-grids. The low frequency transformer is usually used at the Point of Common Coupling (PCC) to connect the low voltage grid and utility network to each other. The conventional 50Hz transformer results in enhanced low voltage-grid power management system during grid-connected operation. In this pap...

In this work we consider Symplectic Runge Kutta Nyström methods with five stages. A new fourth algebraic order method with phase-lag order eight is presented. Also the symplectic Runge Kutta Nyström of Calvo and Sanz Serna with five stages and fourth order is modified to produce a phase-fitted method. We apply the new methods on several Hamiltonian systems and on the computation of the eigenval...

A fundamental aspect of predictive microbiology is the shape of the microbial growth curve and many models are used to fit microbial count data, the modified Gompertz and Baranyi equation being two of the most widely used. Rapid, automated methods such as turbidimetry have been widely used to obtain growth parameters, but do not directly give the microbial growth curve. Optical density (OD) dat...

Cortical neurons in vivo undergo a continuous bombardment due to synaptic activity, which acts as a major source of noise. Here, we investigate the effects of the noise filtering by synapses with various levels of realism on integrate-and-fire neuron dynamics. The noise input is modeled by white (for instantaneous synapses) or colored (for synapses with a finite relaxation time) noise. Analytic...

We use the technique of wavelet analysis to quantitatively investigate the role of solar variability in forcing terrestrial climate change on solar cycle timescales (roughly 11 years). We examine the connection between mean annual solar irradiance, as reconstructed from sunspot and isotope records, and the climate, as proxied by two Northern Hemisphere surface air temperature reconstructions. B...

The specific activity of the periplasmic hydrogenase from Desulfovibrio gigas is increased approximately 10-fold in the Hz utilization assay with benzyl viologen by several hours of incubation under an atmosphere of Hz. After a variable lag phase during which residual traces of O2 are removed, the reversible activation is exponential. The extent of activation is dependent on pH and the redox po...

In this paper, the tracking control problem of a class of uncertain Euler-Lagrange systems subjected to unknown input delay and bounded disturbances is addressed. To this front, a novel delay dependent control law, referred as Adaptive Robust Outer Loop Control (AROLC) is proposed. Compared to the conventional predictor based approaches, the proposed controller is capable of negotiating any inp...

The use of frequency-weighted performance indices in linear quadratic (LQ) optimal control has been the subject of recent r e ~ e a c h ' ~ . The primary motivation for frequency-weighting is the possibility of enhancing the robustness of LQ designs in critical frequency bands. A preliminary study3 of the case where high frequencies in the control are weighted more heavily has shown that the op...