Fast functional modelling of diode-bridge rectifier using dynamic phasors

In this paper, a functional model for diode-bridge rectifiers is developed based on the dynamic phasor concept. The developed model is suitable for accelerated simulation studies of the electric power systems under normal, unbalanced and line faulty conditions. The high accuracy and efficiency of the developed model have been demonstrated by comparison against three-phase time-domain model and against the model employing synchronous space-vector representations. The experimental verification of the developed model is also reported. In addition, an error analysis shows that the error of the developed model is less than 10% at the most severe unbalanced conditions. The prime purpose of the model is for the simulation studies of more-electric aircraft power architectures at a system level; however it can be directly applied for simulation study of any other electrical power system interfacing with uncontrolled diode bridge rectifiers

Discrimination in hiring against immigrants and ethnic minorities: the effect of unionization

There has been a long debate concerning whether unions are exclusive or inclusive with respect to immigrants and ethnic minorities. In the exclusive view of unions, unionization is expected to increase the likelihood of employers asking questions that discriminate against immigrants and ethnic minorities and decrease the likelihood of employers asking Equal Employment Opportunity (EEO) questions related to immigrant or ethnic minority status. The contrary is expected for the inclusive view. Our analysis, using New Zealand data for job applications, provides some support for the inclusive view of unions, as the higher the unionization rate, the more likely EEO information is sought, but no relationship is found between unionization rate and discriminatory questioning. This suggests that unions are probably helpful in promoting diversity but not yet in combating discrimination against immigrants and ethnic minorities in hiring