• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.5
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• pp.1068-1073
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• 2004

5 V/500 mA transless type power module was designed by using a semiconductor switching technique for a small-sized electric power source. It used voltage drop type chopper method, and is composed of switching circuit, control circuit, voltage detect circuit, and constant voltage circuit. The switching power module which is designed in this study, showed load regulation of 0.2 V, line regulation of 0.1 V, output ripple of 85 mVp-p, switching frequency of 64.7 kHz, maximum power efficiency of 58 %, and satisfied its reliability and EMC test.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.5
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• pp.838-844
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• 2015

Latest development of ICT makes building, including houses, factories and public facilities, more intelligent and automatized. It follows that a wide variety of electric and ICT installations are adopted along with micro electronic equipments. Corresponding to such changes, the frequency of lightning increases due to the abnormal climate. The major damage by lightning surge is disconnection and malfunction of facilities. It is necessary, therefore, to make a regulation of inspection and maintenance for lightning protection facilities. This paper deals with main issues of a regulation draft of inspection and maintenance for lightning protection facilities based on IEC 62305

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.64-68
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• 2001

This paper presents an innovative prototype of a new conceptual electromagnetic induction heated type far infrared rays radiant heating appliance using the voltage-fed edge-resonant ZVS-PWM high frequency inverter using IGBTs for food cooking and processing which operates under a constant frequency variable power regulation scheme. This power electronic appliance with soft switching high frequency inverter using IGBTs has attracted special interest from some advantageous viewpoints of safety, cleanliness, compactness and rapid temperature response, which is more suitable for consumer power electronics applications.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.6264-6269
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• 2014

This study examined the state of the UWB frequency band of foreign policy for application to domestic findings. The results confirmed that the UWB frequency can be prescribed mainly for use in a communication service area, unlike foreign countries, such as the United States and Europe for the current technology standard. On the other hand, the expansion of the UWB service area to various fields may appear as interference in the domestic industry protection and enable these rules. Therefore, the UWB frequency should be used in other areas except for broadcast and communication, if the output meets the specified criteria, as in the case of a foreign country. This is thought to be helpful for protecting the domestic industry and activated services.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.8
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• pp.1339-1348
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• 2008

According to diffusion and wide utilization of Radio telecommunication, demands of radio frequency source are increasing. Thus, we have o continuously study on regulations which should be managed efficiently and usefully for father technical developing. In this paper dispute bout developing radio frequency police depends on changes of conditions and sing radio frequency source depend on a variation of environment and an advance of technique and then we consider a international agreement and an amendment of international regulations for an alternative proposal so that we suggest foundations of national radio regulations for revisions and decisions connect with radio frequency control policies and rules.

• Journal of Power Electronics
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• v.4 no.3
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• pp.138-151
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• 2004

In this paper, a constant frequency phase shifting PWM-controlled voltage source full bridge-type series load resonant high-frequency inverter using the $4^{th}$ generation IGBT power modules is presented for innovative consumer electromagnetic induction heating applications, such as a hot water producer, steamer and super heated steamer. The bridge arm side link passive capacitive snubbers in parallel with each power semiconductor device and AC load side linked active edge inductive snubber-assisted series load resonant tank soft switching inverter with a constant frequency phase shifted PWM control scheme is evaluated and discussed on the basis of the simulation and experimental results. It is proved from a practical point of view that the series load resonant and edge resonant hybrid high-frequency inverter topology, what is called, DE class type, including the variable-power variable-frequency regulation function can expand zero voltage soft switching commutation area even under low output power setting ranges, which is more suitable and acceptable for newly developed induction heated dual pack fluid heaters. Furthermore, even the lower output power regulation mode of this high-frequency load resonant tank inverter circuit is verified so that this inverter can achieve ZVS with the aid of the single auxiliary inductor snubber.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1066-1071
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• 2005

This paper presents the two lossless auxiliary inductors-assisted voltage source type half bridge (single ended push pull: SEPP) series resonant high frequency inverter for induction heated fixing roller in copy and printing machines. The simple high-frequency inverter treated here can completely achieve stable zero current soft switching (ZCS) commutation for wide its output power regulation ranges and load variations under its constant high frequency pulse density modulation (PDM) scheme. Its transient and steady state operating principle is originally described and discussed for a constant high-frequency PDM control strategy under a stable ZCS operation commutation, together with its output effective power regulation characteristics-based on the high frequency PDM strategy. The experimental operating performances of this voltage source SEPP ZCS-PDM series resonant high frequency inverter using IGBTs are illustrated as compared with computer simulation results and experimental ones. Its power losses analysis and actual efficiency are evaluated and discussed on the basis of simulation and experimental results. The feasible effectiveness of this high frequency inverter appliance implemented here is proved from the practical point of view.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.415-420
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• 2005

This paper presents the two lossless auxiliary inductors-assisted voltage source type half bridge (single ended push pull: SEPP) series resonant high frequency inverter for induction heated king roller in copy and printing machines. The simple high-frequency inverter treated here can completely achieve stable zero current soft switching (ZCS) commutation for wide its output power regulation ranges and load variations under its constant high frequency pulse density modulation (PDM) scheme. Its transient and steady state operating principle is originally described and discussed for a constant high-frequency PDM control strategy under a stable ZCS operation commutation, together with its output effective power regulation characteristics-based on the high frequency PDM strategy. The experimental operating performances of this voltage source SEPP ZCS-PDM series resonant high frequency inverter using IGBTs are illustrated as compared with computer simulation results and experimental ones. Its power losses analysis and actual efficiency are evaluated and discussed on the basis of simulation and experimental results. The feasible effectiveness of this high frequency inverter appliance implemented here is proved from the practical point of view.

• Journal of the Korean Society of Safety
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• v.30 no.6
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• pp.26-33
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• 2015

This study suggests systematic procedures to improve safety policies on prevention of industrial accidents associated with industrial machines and devices. Specifically, new method of cause analysis of industrial accidents associated with industrial machines and devices is suggested and the related accident data are re-analyzed. Effectiveness of direct safety regulations such as safety certification, self-declaration of conformity, safety device regulation and safety inspection of industrial machines and devices are also analyzed. Based on those analysis results, transition from the current user-oriented safety device regulation to more balanced direct regulations on both manufacturer and user is suggested. Together with severity and frequency of industrial accidents, unit severity and unit frequency need to be taken into account to further assess the risk associated with a particular industrial machine or device. Balance between safety regulations will be realized by proper adjustment of lists of safety certification and inspection, and certification and inspection standards. This will also guarantee the maximum benefit over cost in such safety regulations.

• Journal of the Korean Home Economics Association
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• v.45 no.2
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• pp.1-22
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• 2007

The purpose of this study was to investigate the effect of mother's characteristics, mediated by disciplinary methods and young children's emotional regulation, on young children's aggression. Subjects of this study consisted of 342 young children drawn from seven preschools in Cheongju city. The pilot study was used to examine the applicability of survey instrument. Data were analyzed by the method of frequency, percentage, Cronbach' ${\alpha}$, factor analysis, T-test. F-test, and Duncan post-hoc test using SPSSWIN program. The test of model was done with analysis of correlational matrix in LISREL VII package using a maximum likehood estimation. The results of this research were as follows: First, there were statistically significant differences in mother's characteristics consisting of neurosis symptom and extroversions, disciplinary methods consisting of coercive-punishment and indifferent-irresponsibility, young children's emotional regulation, and young children's aggression consisting of relation and overtness according to some socio-demographic variables. Girls had the higher emotional regulation than boys. Second, the direct effects of disciplinary methods and emotional regulation on boys' aggression were different in between relational and overt aggression. Third, the variables predicting boys' emotional regulation directly were the same in both relational and overt aggression. Forth, the direct effect of mother's characteristics on disciplinary methods was different in between coercive-punishment and indifferent-irresponsibility. Fifth, the indirect effects of mother's characteristics, mediated by disciplinary methods and young children's emotional regulation, on young children's aggression were partly supported in this study. Sixth, the theoretical model of the impact of mother's characteristics, disciplinary methods, and young children's emotional regulation on young children's aggression was different according to gender.