• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.8 s.99
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• pp.783-789
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• 2005

In this paper, a novel design and implementation of a dual-band directional coupler based on RF IPD(Integrated Passive Device)-on-glass technology is proposed, which can be adopted in GSM/GPRS cellular phones for closed loop power control at the output of the power amplifier. The proposed coupler has a compensation capacitor to improve the directivity, and was designed using a new diplexing structure to minimize the cross-band isolation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.468-478
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• 2018

The goal of this study is to propose a new directivity for business training based on an analysis of the learner's satisfaction, the cause of the learning effect and the cause of reenrollment in smart learning courses. The data from 878 learners of 11 companies was analyzed by ANOVA and multiple regression analysis and the following results were obtained. First of all, the satisfaction of studying by smart learning showed various results depending on the motivation, process and contents of studying. According to the results, high rates of satisfaction were observed when the people take an active part in studying, as reflected in the frequency and time of studying. Also, when the learning contents were presented in an animated manner, the satisfaction of the students was increased. Second, the motivation of the students to participate in the smart learning and study process was reflected in the frequency, time and quality of their studies, thus confirming the learning effect. Lastly, the satisfaction and effectiveness of studying by smart learning are the causes of reenrollment. Based on the analysis results, it was concluded that the corporation's support and proper compensation are needed to increase the rate of satisfaction and the effectiveness of smart learning from the corporation's perspective. Also, from the viewpoint of the smart learning system operators, it is necessary to find ways of developing the learning contents.