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Traditional power-system dynamic simulation tools make a number of simplifying assumptions to speed up computations; thus, they can only capture snapshots of the system operation, ignoring the dynamics between states. This paper applies the shifted-frequency-analysis (SFA) theory to the Electromagnetic Transients Program (EMTP) simulator in order to efficiently obtain the time-domain simulation results in the neighborhood of the fundamental frequency without making quasi-steady-state or other simplifying assumptions. The SFA-based EMTP simulator can provide dynamic-phasor results that accurately trace the evolution of the system state in three-phase power systems. Dynamic phasors provide envelopes of the time-domain waveforms and can be accurately transformed back to instantaneous time values. Test cases have verified the usefulness of the SFA-based dynamic simulation method. [ABSTRACT FROM PUBLISHER]

A new adaptive circuit design approach is proposed and analyzed employing independently biased back-gated Double-Gate MOSFET (DGMOSFET) devices. Threshold voltage tuning using back-gate of the DGMOSFET was compared with a conventional body-bias method. The technique is a promising solution to control the transistor's threshold voltage while reducing undesirable effects at the sub-50-nm device technology nodes. An automatic adaptive circuit for threshold voltage tuning was implemented using DGMOSFET devices in 45 nm CMOS technology. Simulation results show that this circuit compensates for static and dynamic variations. This adaptation approach using DGMOSFETs along with adaptive supply voltage scaling allows simultaneous optimization of power and performance according to application-specific workload and requirements. Simulation results using a 45 nm CMOS technology indicate that this adaptive circuit design can provide 50% higher performance for the same energy, or consume 40% less energy for the same performance. In contrast to conventional methods which only employ dynamic voltage scaling, adaptive tuning of threshold voltages reduces power consumption while maintaining its noise margin. [ABSTRACT FROM AUTHOR]