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An optofluidic maskless photopolymerization process was developed for in situ negatively charged nanoporous hydrogel [poly-AMPS (2-acrylamido-2-methyl-1-propanesulfonic acid)] fabrication. The optofluidic maskless lithography system, which combines a high power UV source and digital mirror device, enables fast polymerization of arbitrary shaped hydrogels in a microfluidic device. The poly-AMPS hydrogel structures were positioned near the intersections of two microchannels, and were used as a cation-selective filter for biological sample preconcentration. Preconcentration dynamics as well as the fabricated polymer shape were analyzed in three-dimensions using fluorescein sample and a confocal microscope. Finally, single-stranded DNA preconcentration was demonstrated for polymerase chain reaction-free signal enhancement. 相似文献
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多元化战略是企业扩展业务、增强企业竞争力的关键战略之一。然而,在不同的宏观环境下,关于多元化战略与企业绩效之间关系的实证研究往往得到不一致的结果。与以往的研究不同,本文采用固定的研究对象,但在截然不同的经营环境中,观察其多元化战略与企业绩效之间的关系。通过利用韩国30家大型企业集团1997年亚洲金融危机前后14年(1990~1996, 1999~2005)的财务数据,以企业经营管理因素为自变量,企业绩效为因变量,衡量不同多元化程度的企业绩效差异。结果表明:(1)金融危机促进了企业对内部管理因素的重视,并使企业改变对于危机管理的态度;(2)危机之后,企业的经营因素与经营成果之间的正相关关系更加显著;(3)低多元化企业较高多元化企业表现出更好的经营绩效。 相似文献
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M.J. Park O.M. Kwon Ju H. Park S.M. Lee E.J. Cha 《Journal of The Franklin Institute》2012,349(5):1699-1720
This paper proposes new delay-dependent synchronization criteria for coupled stochastic neural networks with time-varying delays and leakage delay. By constructing a suitable Lyapunov–Krasovskii's functional and utilizing Finsler's lemma, novel synchronization criteria for the networks are established in terms of linear matrix inequalities (LMIs) which can be easily solved by using the LMI toolbox in MATLAB. Three numerical examples are given to illustrate the effectiveness of the proposed methods. 相似文献
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Kwon Kyong-Ah Ford Timothy G. Salvatore Alicia L. Randall Ken Jeon Lieny Malek-Lasater Adrien Ellis Natalie Kile Mia S. Horm Diane M. Kim Sun Geun Han Minkyung 《Early Childhood Education Journal》2022,50(1):157-168
Early Childhood Education Journal - The majority of teachers in the early care and education (ECE) workforce face disparities in physical and psychological well-being as well as working conditions.... 相似文献
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Kwon Kyong-Ah Jeon Shinyoung Castle Sherri Ford Timothy G. 《Early Childhood Education Journal》2022,50(7):1221-1232
Early Childhood Education Journal - Using the nationally representative Head Start Family and Child Experiences Survey 2014 (FACES 2014), this study examined the associations... 相似文献
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This study focuses on 2 sound elements of sports broadcasting. Specifically, this study sought to explore the differential and combinational effects of commentary sound and on-site spectator sound on the motor resonance and attentional process of viewers. To analyze, this study selected electroencephalogram (EEG) time-frequency analysis using wavelet transforms as a method to observe the viewers’ direct brain responses. The overall findings suggest that delivering on-site spectator’s sound needs to be regarded as important as it can have a significant effect on viewers’ sports-viewing experience. 相似文献
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Although there is a considerable body of research regarding the relationships between the sociopolitical and economic transition and its implications for the education system in South Korea, there is little known about how sociopolitical and economic factors affect labor education practice in South Korea. The premise of the study is that the development of labor education is driven not only by workers’ needs but also by the state's policy to increase productivity while keeping the labor movement and political expression under control. Since many educators often overlook the importance of labor education by excluding it from adult education, very few studies have been conducted to identify the relationship between sociopolitical and economic factors and labor education in South Korea. The purpose of the study is thus to examine the effect of particular combinations of social, political, and economic forces on the development and expansion of labor education in South Korea during the period between the 1960s and the 1990s. The results of the study can be compared with studies of other countries that underwent a similar pattern of political and economic transformation. 相似文献
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Hyun-Joo Jeon Kyong-Ah Kwon Bridget Walsh Melissa M. Burnham Yun-Jung Choi 《Early education and development》2019,30(1):131-144
Research Findings: This study used teacher questionnaires to investigate the relationships of early childhood education teachers’ depressive symptoms, professional motivation, and job-related stress to their beliefs about children and teaching practices. Teachers (N = 207) were recruited from early childhood education programs in the southern United States. Path analyses showed that teachers who exhibited fewer depressive symptoms were more likely to have a career orientation to their jobs and indicated feeling less job-related stress. Teachers with a career orientation to their jobs were also more likely to have child-centered beliefs and endorse developmentally appropriate teaching practices. Teachers’ job-related stress, however, was not related to beliefs about children or teaching practices. Practice or Policy: These results suggest that teachers’ psychological and job-related well-being are linked to their beliefs about children and teaching practice in early childhood education. It is therefore important to provide support systems and preventive programs for teachers to enhance their well-being. 相似文献