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The goals of this research were to explore the current literature regarding associations between psychological stress and adverse fetal outcome, associations between aerobic exercise and psychological stress reduction, and associations between aerobic exercise and fetal outcome. The published studies that were located provide evidence of the following: 1) Stress reactivity increases physiologically during pregnancy, 2) pregnant women may experience additional stressors that are usually not experienced in a nonpregnant state, 3) psychological stress in pregnancy is associated with adverse fetal outcome, 4) exercise can be a method of stress reduction, 5) exercise in pregnancy is not associated with adverse fetal outcome, and 6) exercise in pregnancy may provide benefit to the fetus. Data were analyzed from an original study and associations were reported between psychological stress-management activities and participation in aquatic aerobic exercise classes. No reports were available investigating an exercise-induced reduction in psychological stress with fetal outcome. 相似文献
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The University of Florida offers an online professional practice Ed.D. focused on Educational Technology. Twenty-three students have completed professional practice dissertations and graduated since the program’s inception in 2008. The purpose of this article is to share what these dissertations have looked like and to begin a dialogue about professional practice dissertations completed in online educational technology programs. Specifically, we (1) provide an overview of different ways professional practice Ed.D. dissertations are structured, (2) share guiding principles for professional practice dissertations in our Ed.D. program, (3) analyze the ways in which these guiding principles played out in the dissertations and (4) discuss the implications of our analysis for our program and for other online professional practice programs in Educational Technology. 相似文献
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Kara Jackson 《学习科学杂志》2013,22(1):111-150
This article reports on an ethnographic study of a 10-year-old's pursuit of school-based mathematics across school and home to suggest that participating in school-based mathematics is a cross-setting phenomenon in at least 2 ways. First, I illustrate how accomplishing school-based mathematics literally extends into the home and how individuals recruit resources from their histories of participation in alternative settings to accomplish the work of school-based mathematics. Second, I show how a youth's social identification in the classroom is shaped by his teacher's partial accounts of how learning is arranged for in the home. Approaching participation in school-based mathematics as a cross-setting phenomenon illustrates the complexity inherent in participating in schooling and raises questions about how to coordinate schooling across school and home settings. 相似文献
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Ahmed Bendib Aissa Chouder Kamel Kara Abdelhammid Kherbachi Said Barkat Walid Issa 《Journal of The Franklin Institute》2019,356(13):6842-6874
In a microgrid (MG) topology, the secondary control is introduced to compensate for the voltage amplitude and frequency deviations, mainly caused by the inherent characteristics of the droop control strategy. This paper proposes an accurate approach to derive small signal models of the frequency and amplitude voltage at the point of common coupling (PCC) of a single-phase MG by analyzing the dynamics of the second-order generalized integrator-based frequency-locked loop (SOGI-FLL). The frequency estimate model is then introduced in the frequency restoration control loop, while the derived model of the amplitude estimate is introduced for the voltage restoration loop. Based on the obtained models, the MG stability analysis and proposed controllers’ parameters tuning are carried out. Also, this study includes the modeling and design of the synchronization control loop that enables a seamless transition from island mode to grid-connected mode operation. Simulation and practical experiments of a hierarchical control scheme, including traditional droop control and the proposed secondary control for two single-phase parallel inverters, are implemented to confirm the effectiveness and the robustness of the proposal under different operating conditions. The obtained results validate the proposed modeling approach to provide the expected transient response and disturbance rejection in the MG. 相似文献
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Kara Long Santi Thompson Sarah Potvin Monica Rivero 《Cataloging & classification quarterly》2017,55(3):107-128
Increasingly, metadata standards have been recognized as constructed rather than neutral. In this article, we argue for the importance of a documentation approach to metadata standards creation as a codification of this growing recognition. By making design decisions explicit, the documentation approach dispels presumptions of neutrality and, drawing on the “wicked problems” theoretical framework, acknowledges the constructed nature of standards as “clumsy solutions.” 相似文献
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This article presents a new approach to modeling information flows within today's information systems environments characterized by electronic commerce. We treat information as a resource whose value is fundamentally multidimensional in nature. In this article we consider the economic and psychological dimensions of the value of information. It is argued that it is meaningless to model the value of information in isolation away from the context and the specific parties between which this information is exchanged. We therefore focus exclusively on modeling information flows rather than information itself. To achieve this, we propose a formal framework for describing transactions involving information flows. The framework consists of a generalized model for representing information transactions and for defining a set of fundamental properties of multiparty transactions. These properties are fairness, constructiveness, and monopoly. Where applicable, they are defined for individuals, transactions, and a system of transactions. The proposed model reveals the nature of individual transactions and markets, and consequently has important implications for simulation of market scenarios and to help arrive at effective policies for pricing and market regulations. 相似文献
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Asia Pacific Education Review - The current study reports the findings of the first step of a comprehensive performance improvement study, identification of the optimal behaviors. In this sense,... 相似文献