the well-known electro-mechanical analogy that equates current, voltage, resistance, inductance and capacitance to force, velocity, damping, spring constant and mass has a shortcoming in that mass can only be used to simulate a capacitor which has one terminal connected to ground. a new model that was previously proposed by the authors that combines a mass with a pulley (mp) is shown to simulat...

abstract today, debt stabilization in an uncertain environment is an important issue. in particular, the question how fiscal and monetary authorities should deal with this uncertainty is of much importance. especially for some developing countries such as iran, in which on average 60 percent of government revenues comes from oil, and consequently uncertainty about oil prices has a large effect ...

—This document presents an introduction of two commonly used power system differential algebraic equations for studying electromechanical oscillation and transient stability. Two types of generator models are used to formulate the power system model, respectively: the second-order classical model and the fourth-order generator model. An example is provided on the IEEE 9-bus system.

This paper addresses an approximation-based anti-windup (AW) control strategy for suppressing the windup effect caused by actuator saturation nonlinearity in proportional–integral–derivative (PID) controlled systems. The effect of actuator constraint is firstly regarded as a disturbance imported to the PID controller. The external disturbance can then be modeled by a linear differential equatio...

We describe a differential photoacoustic (PA) imaging system in which almost equal intensity beams modulated 180' out of phase illuminate two regions of a sample in a PA cell. For two regions that are both optically and thermally similar and also homogeneous, the resulting signal is almost zero but if one region has a sub-surface defect this will give an increased signal. This differential sign...

In this study the interaction between self-excited and paramet rically excited oscillations in two-degree-of-freedom systems with quadratic nonlinearities is investigated. The fundamental parametric resonance of the first mode and 3:1 internal resonance is considered, followed by 1:2 internal and parametric resonances of the second mode. The method of multiple time scales is applied to derive f...