In this article, a semi-analytical method to estimate elastic follow-up factor as input to estimate the transient creep C(t) parameter under secondary loading is presented and validated against finite element results for a cracked two-bar structure under constant displacement loading. Predicted values of C(t) agree well with the finite element results for both elastic-creep cases and for elastic-plastic cases with the same creep and plastic hardening exponents. For elastic-plasticcreep cases with different creep and plastic hardening exponents, the proposed method gives good predictions at long time but can under-or over-predict C(t) at short time.

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This paper presents the analysis and design of an active electromagnetic interference (EMI) filter (AEF) for the common-mode (CM) noise reduction of switching power converters. The features of the several types of AEFs are discussed and compared in terms of implementation. The feed-forward AEF with a voltage-sensing and voltage-cancellation (VSVC) structure is implemented for an LLC resonant converter to replace a multiple-stage passive EMI filter and thereby reduce CM noise. The characteristics and performance of the VSVC-type AEF are investigated through theoretical and experimental works.

Maternal interaction behavior, language input and children's language of 34 multicultural families were compared with those of ordinary families. MLU's of multicultural mothers and their children were shorter than those of ordinary Korean mothers and children. Positive maternal interaction behaviors of multicultural mothers were significantly lower than those of ordinary mothers. Correlational analyses revealed that there were positive correlations among maternal interaction behaviors, mother's MLU and children' MLU in multicultural families. However, there were no such correlations in ordinary families. Findings suggest language education and support for multicultural mothers be an effective policy for their children's language development.

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