Search

This study investigates the impact of different modes and tailor-made response enhancing measures (TMREM)—such as bilingual interviewers with a shared ethnic background and translated questionnaires—on the measurement of substantive variables in surveys among minority ethnic groups in the Netherlands. It also provides insight into the ability to detect mode measurement effects of a recently developed method for disentangling mode measurement and mode selection effects, as well as into the tenability of the assumptions underlying this method. The data used in this study come from a large-scale survey design experiment among the four largest non-Western minority ethnic groups in the Netherlands comparing single-mode computer-assisted personal interviewing (CAPI) and sequential computer-assisted web interviewing, computer-assisted telephone interviewing, and CAPI-MM. The number and intensity of the TMREM varied among the four ethnic groups. The results show that mode measurement effects occur among all ethnic groups and are the result of a combination of the presence or absence of an interviewer and TMREM. Mode measurement effects occur more often on sociocultural questions, but also, on occasion, on more sociostructural or background questions. The method used to disentangle mode measurement and mode selection effects can be applied to detect mode measurement effects, but one should be cautious in interpreting them. Implausible mode measurement effects can be caused by the violation of the assumptions underlying this method. [ABSTRACT FROM AUTHOR]

A novel method is proposed to locate the source of events in power distribution systems by using distribution-level phasor measurement units, a.k.a., micro-PMUs. An event in this paper is defined rather broadly to include any major change in any component across the distribution feeder. The goal is to enhance situational awareness in distribution grid by keeping track of the operation (or misoperation) of various grid equipment, assets, distribution energy resources, loads, etc. The proposed method is built upon the compensation theorem in circuit theory to generate an equivalent circuit to represent the event by using voltage and current synchrophasors that are captured by micro-PMUs. Importantly, this method makes critical use of not only magnitude but also synchronized phase angle measurements, thus, it justifies the need to use micro-PMUs, as opposed to ordinary RMS-based voltage and current sensors. The proposed method can work with data from as a few as only two micro-PMUs. The effectiveness of the developed method is demonstrated through computer simulations on the IEEE 123-bus test system, and also on micro-PMUs measurements from a real-life 12.47 kV test feeder in Riverside, CA. The results verify that the proposed method is accurate and robust in locating the source of different types of events on power distribution systems. [ABSTRACT FROM AUTHOR]

A gender difference in motor activity level (AL) is well established for children, but questions about the existence and nature of an infant sex difference remain. To assess these questions, we applied meta-analytic procedures to summarize 46 infancy studies comprising 78 male–female motor activity comparisons. Our results showed that, as with children, male infants were more active than females. Objective measures of infant AL estimated the size of this difference to be 0.2 standard deviations, though subjective parent-report measures estimated the difference to be smaller. We argue that this early sex difference in activity level is biologically based. However, socialization processes, such as gender-differentiated expectations and experiences, in conjunction with further sex-differentiated biological developments, amplify this early difference to produce the larger gender differences in activity found during childhood. Copyright © 1999 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]