• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.4
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• pp.499-508
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• 1993

This paper has dealt with the design methods and the analysis of frequency characteristics for the power splitters with ferrite toroids, which are extensively used in CATV and/or MATV systems. The theoretical design methods and frequency characteristics of the prototype Wilkinson's 2-way power divider have been reviewed in lumped-element circuits form. On the basis of the design theory of the prototype Wilkinson's power divider, the method compensating of the prototype Wilkinson's power divider has been proposed by means of adding matching transformers. Thus, it has been shown that the theoretical frequency characteristics of the compensated power splitter are improved drastically in comparison with the prototype Wilkinson's power divider. Furthermore, the practical measurements of the frequency characteristics for the fabricated circuits show agreements with the theoretical results, and hence, the validity of the proposed design and analysis methods has been confirmed.

• The Journal of the Korea Contents Association
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• v.19 no.8
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• pp.303-315
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• 2019

In 2018, 14.3 percent of South Korea's elderly population aged 65 or older entered an aged society and is expected to enter a super-aged society with more than 20 percent of the elderly population around 2025. Older adults often visit different medical institutions to take medicine, which requires medication management, such as interaction between each drug. In this study, we wanted to analyze the U.S. system, which specializes in drug management for the elderly, and Korea's system, which is about to enter a super-aged society, to find a systematic way to manage drugs for the elderly. The method of study was a systematic literature study on elderly drug management in Korea and the United States. Studies have shown that the United States has enacted the Medication Therapy Management (MTM) for the elderly and has been running the Senior Drug Enforcement Program. In Korea, a community care business is underway to manage drugs for senior citizens, but it is analyzed that the elderly need to have a special medicine system for senior citizens to use them more safely.

• Journal of the Korean Magnetics Society
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• v.25 no.2
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• pp.58-65
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• 2015

This paper deals with the generating characteristic analysis of permanent magnet linear generator (PMLG) with double-sided Halbach magnet array mover and three phases concentrated stator windings by using analytical method. On the basis of a magnetic vector potential and Maxwell's equations, governing equations are obtained, and magnetization modeling for Halbach magnet array is performed analytically by using the Fourier series. And then, we obtain electrical parameters such as back-EMF constant, resistance, and coil inductance based on magnetic field calculations. Finally, analytical results for generating performance are confirmed by comparing with finite element analysis results.