• Journal of Families and Better Life
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• v.27 no.3
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• pp.159-170
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• 2009

The purpose of this study was (1) to investigate the difference of temperament, self-regulation, and problem behavior according to children's gender and age, (2) to investigate the relationship among three variables by use of canonical correlation analysis. The subjects were 210 children ages from 3 to 5 in five day-care center in Incheon city. The SPSS WIN 12.0 Program was used to analyze the collected data. The statistical methods were Frequency, Percentage, Cronbach's ${\alpha}$, Two-way ANOVA, Correlation analysis, and Canonical Correlation analysis. The major results of this research are summarized as follows: (1) Children's temperament were significantly different by their gender and age. The boys got higher score than girls in adaptability, activity, and total temperament. Girls got higher score than boys in reactivity. The age 3 got higher score than the age 5 in activity and the ages 3, 4 got higher than the age 5 in total temperament. (2) Children's self-regulation were significantly different by their age. The children who were older got higher scores in self-regulation ability. (3) Children's problems behavior were significantly different by their gender and age. The boys got higher score than girls in anxiety behavior, aggressive behavior, hyperactive/distractive behavior, and total problem behavior. And the ages 3, 4 got higher score than the age 5 in anxiety behavior and hyperactive/distractive behavior. The age 4 got higher score the ages 3, 5 in aggressive behavior and the age 3 got higher score the ages 4, 5 in total problem behavior. (4) Canonical correlation results showed that stable temperament and self-regulation were positively correlated and self-regulation and problem behavior were negatively correlated.

• Journal of Distribution Science
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• v.15 no.12
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• pp.53-60
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• 2017

Purpose - This paper analyzes the effect of the handset subsidy and the Mobile Number Portability subscriber subsidy regulation, which are the main regulation adopted in "Law on the Improvement of the Mobile Terminal Distribution System" (Mobile Terminal Distribution Act), on the social surplus, the consumer surplus and profits of telecommunications carriers. We focus our analysis on whether the service charge competition is stimulated enough so that it can compensate for the loss of subsidies. Research design, data, and methodology - We use simple economic model to assess the impact of the handset subsidy and the Mobile Number Portability subscriber subsidy regulation. Unlike the former researches on this topic, we depart from using Hotelling model, and instead use the switching cost model, which uses switching cost as a parameter of market powers of telecommunications carriers. We also study the effect of the two different regulations when they are adopted both independently and concurrently. Results - If the market powers of telecommunications carriers are over certain threshold, contrary to the regulatory agency's assertion, the service charge competition would not be stimulated enough to compensate for the deduction in the subsidies, and thus the consumer surplus is compromised. Number Portability subsidy, especially, undermines the rival's market power and thus reduces the service charge. On the other hand, the regulations will also increase the profits of telecommunications carriers. However, social surplus is maximized when both of the regulations are present because the regulations reduces the frequency of switching handsets inefficiently. Conclusions - In enacting the Mobile Terminal Distribution Act, the telecommunications regulatory agency asserted that the regulation on subsidies will stimulate service charge competition, and in the long run, enhance the consumer surplus. However, contrary to the regulatory agency's assertion, subsidy regulation, especially the regulation on Number Portability subsidy, reduces consumer surplus. On the other hand, the Mobile Terminal Distribution Act can also increase the profits of telecommunications carriers because it decreases competition among the telecommunications carriers. However, the Mobile Terminal Distribution Act can increase the social surplus because it reduces inefficient switching of handsets.

• Journal of the Korea Convergence Society
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• v.12 no.9
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• pp.65-71
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• 2021

The purpose of this study is to investigate the factors that affect stress, emotional regulation, and adjustment to college life of health college students. The survey was conducted from June 21 to 30, 2021 for 190 health students in G and J area. The data were analyzed by frequency analysis, reliability analysis, simple correlation analysis, and multiple regression analysis. The results showed that positive perception had positive correlation with negative perception(r=-.286,p<.01), emotional regulation (r=.296,p<.01), and university life adjustment(r=.520,p<.01). Negative perception was correlated with emotional regulation(r=-.619,p<.01), university life adjustment (r=-.428,p<.01) and negative(-). Emotional regulation had a positive correlation with university life adjustment(r=.341,p<.01). Positive perception, negative perception, and emotional regulation, which are sub-factors of perceived stress, were the factors affecting the adjustment to university life, and the explanatory power was 84%. Therefore, it is necessary to develop a program that can improve the adjustment of college students in health.

• Journal of Power Electronics
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• v.14 no.2
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• pp.302-314
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• 2014

Due to advancements in power electronics and inverter topologies, the current controlled multilevel voltage-source pulse width modulated (PWM) inverter is usually preferred for accurate control, quick response and high dynamic performance. A multilevel topology approach is found to be best suited for overcoming many problems arising from the use of high power converters. This paper presents a comprehensive review and comparative study of several current control (CC) techniques for multilevel inverters with a special emphasis on various approaches of the hysteresis current controller. Since the hysteresis CC technique poses a problem of variable switching frequency, a ramp-comparator controller and a predictive controller to attain constant switching frequency are described along with its quantitative comparison. Furthermore, various methods have been reviewed to achieve hysteresis current control PWM with constant switching frequency operation. This paper complies various guidelines to choose a particular method suitable for application at a given power level, switching frequency and dynamic response.

• Journal of the Korea Society of Computer and Information
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• v.23 no.4
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• pp.167-173
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• 2018

This purpose of this study was to analyze the variables associated with the ethical consumption behavior of children consumers. This subjects were 431 elementary school students. PASW 18.0 was used for data processing to do frequency analysis, T-test, one-way ANOVA, correlation analysis and multiple regression analysis. The results were as follows. First, children consumers tend to a little higher everyday ethical consumption behavior than others-oriented ethical consumption behavior. Second, as a result of analyzing ethical consumption behavior according to social economic variables, a high tendency of ethical consumption behavior was shown in groups that personality is extrovert and their household economic status is over upper middle class and father's age is higher. Third, the variables affecting ethical consumption behavior of children consumers were self-regulation ability, materialism, altruism, personality tendency, household economic status. Materialism had a negative effect but self-regulation ability, materialism, altruism, personality tendency, and household economic status had a positive effect.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.159-162
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• 2000

In his paper the principle of using coreless printed circuit board (PCB) based transformer in 2.3MHz, 12W class ZVS Forward DC-DC converter has been successfully demonstrated. With no core loss coreless PCB transformer and inductor are found to have favorable characteristics at high frequency operations. The maximum power conversion efficiency is 80% Even for high operating frequency an efficiency greater than 70% can be obtained with under 0.7% regulation error.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.1100-1103
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• 1992

Two different resonance inverters used as fluorescent lamp ballast are based on the self oscillation at the series resonance of the circuit components. Each circuit is simulated on a computer in order to explain its function and the variation of the circuit variables for each of the circuit elements. Experimental results have bean carried out on the unsymmetrical scheme to indicate the voltage and current of the fluorescent lamp operation at the high frequency.

• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.381-384
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• 1988

This paper analysed basic operation in Zero-voltages-switching quasi-resonant buck converter and considered steady state characteristics. Especially, it is confirmed that converter operating at maximum 1MHz switching frequency in load characteristics. In this paper, a novel slope method is proposed and implemented in regulation characteristics analysis. It is proved that experimenental results coincide with theory results.

• Proceedings of the IEEK Conference
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• 2000.06e
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• pp.9-12
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• 2000

This paper describes the modeling and experimental results of coreless printed circuit board (PCB) based transformer that can be used for power conversion at high frequency operation. The principle of using coreless PCB based transformer in 2MHz, 10W class ZVS Flyback DC-DC converter has been successfully demonstrated. The maximum power conversion efficiency is 79%. Even for high operating frequency, an efficiency greater than 70% can be obtained with under 1% regulation error.

• 전기의세계
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• v.28 no.1
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• pp.53-58
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• 1979

In the microwave heating system, a ferroresonant transformer is used to regulate the magnetron power fluctuation. For the simplification, nonlinear characteristics of the transformer and the magnetron are idealized to be piecewise linear. Dipped peak shape of the magnetron current is explained qualitatively by considering the fundamental and third harmonic frequency components in the circuit. Design equations providing the values of the leakage inductance, turn ratio of the transformer and the capacitance are derived analytically by cosnidering the fundamental frequency component only. The ferroresonant transformer is designed to obtain a required regulation and high input power factor from the derived design equations, and analytical calculations are compared with experimental measurements.