Based on Fourier series theory, for almost periodic functions, the general as well as the specific harmonic‐balance model of induction machines is presented together with a brief…
Abstract
Based on Fourier series theory, for almost periodic functions, the general as well as the specific harmonic‐balance model of induction machines is presented together with a brief derivation. Whereas the general model refers to both symmetrical and asymmetrical machines, the specific one is valid for only the former ones, with windings without parallel branches. The specific model permits classification of all symmetrical machines into three categories. The classification preserves its usefulness for machines not strictly fulfilling assumptions for the validity of the specific model. Expressions for the asynchronous and synchronous torque components are derived. Categories as well as frequencies of both the slot harmonics and the synchronous torques are listed in four tables referring to machines with one to four pole pairs.
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The contribution deals with the dynamics of induction machine during reswitching process from the main feeder on the stand‐by one. The main feeder may be a current source inverter…
Abstract
The contribution deals with the dynamics of induction machine during reswitching process from the main feeder on the stand‐by one. The main feeder may be a current source inverter in which case the machine, before switching off, may be operated with lower frequency than the frequency of the stand‐by supply net. It causes that the electromotive force on the opened machine terminals is no longer a measure of the magnitude of the rotor currents. The analysis was carried out with recognition for the magnetic saturation of the main flux.
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Erica S. Jablonski, Chris R. Surfus and Megan Henly
This study compared different types of full-time caregiver (e.g., children, older adults, COVID-19 patients) and subgroups (e.g., disability, race/ethnicity, sexual orientation…
Abstract
Purpose
This study compared different types of full-time caregiver (e.g., children, older adults, COVID-19 patients) and subgroups (e.g., disability, race/ethnicity, sexual orientation) in the United States during the COVID-19 pandemic for potentially meaningful distinctions.
Methodology/Approach
Data from the 9,854 full-time caregivers identified in Phase 3.2 (July 21–October 11, 2021) of the US Census Household Pulse Survey (HPS) were analyzed in this study using multinomial logistic regression to examine relationships between caregiver types, marginalized subgroups, generation, and vaccination status.
Findings
The prevalence of caregiving was low, but the type of full-time caregiving performed varied by demographic group (i.e., disability, race/ethnicity, sexual orientation, gender, generation, and vaccination status). The relative risk of being a COVID-19 caregiver remained significant for being a member of each of the marginalized groups examined after all adjustments.
Limitations/Implications
To date, the HPS has not been analyzed to predict the type of full-time informal caregiving performed during the COVID-19 pandemic or their characteristics. Research limitations of this analysis include the cross-sectional, experimental dataset employed, as well as some variable measurement issues.
Originality/Value of Paper
Prior informal caregiver research has often focused on the experiences of those caring for older adults or children with special healthcare needs. It may be instructive to learn whether and how informal caregivers excluded from paid employment during infectious disease outbreaks vary in meaningful ways from those engaged in other full-time caregiving. Because COVID-19 magnified equity concerns, examining demographic differences may also facilitate customization of pathways to post-caregiving workforce integration.