• Journal of Power Electronics
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• v.10 no.3
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• pp.328-333
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• 2010

A photovoltaic power conditioning system (PV PCS) that contains single-phase dc/ac inverters tends to draw an ac ripple current at twice the output frequency. Such a ripple current perturbs the operating points of solar cells continuously and it may reduce the efficiency of the current based maximum power point tracking technique (CMPPT). In this paper, the ripple current generation in a dc link and boost inductor is analyzed using the ac equivalent circuit of a dc/dc boost converter. A new feed-forward ripple current compensation method to incorporate a current control loop into a dc/dc converter for ripple reduction is proposed. The proposed feed-forward compensation method is verified by simulation and experimental results. These results show a 41.8 % reduction in the peak-to peak ac ripple. In addition, the dc/ac inverter control system uses an automatic voltage regulation (AVR) function to mitigate the ac ripple voltage effect in the dc link. A 3kW PV PCS prototype has been built and its experimental results are given to verify the effectiveness of the proposed method.

• Science of Emotion and Sensibility
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• v.17 no.1
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• pp.63-70
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• 2014

Emotion regulation has been suggested as a pathway through which personality traits (e.g., extraversion or neuroticism) affect psychological well-being. However, the pathway needs further investigation across cultures due to variations in parts of the relationship reported in recent culture research. With an aim of improving current understanding of the pathway, we investigated the role of emotion regulation mediating the link between personality traits and well-being across two college samples from different cultural backgrounds: Korea and the United States (US). Results of mediation analysis revealed that the extraversion-well-being relationship was fully mediated by the degree to which individuals regulate negative emotions in both Korean and US samples. However, the neuroticism-well-being relationship was partially mediated by emotion regulation in the US sample, while it was fully mediated in the Korean sample. The role of emotion regulation differently functioning across cultures suggests the importance of investigating cultural-specific mechanism of psychological processes.

• Journal of Power System Engineering
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• v.11 no.4
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• pp.12-17
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• 2007

Recently, many small and medium size diesel vehicles have been equipped with turbocharger and EGR system to get high performance and reduce $NO_x$ emissions but its application to heavy-duty diesel engine is not common yet. In this work, the simulation model for EURO-3 engine was developed using WAVE and then its performance and emission level were verified by comparing with experimental results. The possibility of current EURO-3 engine equipped with LPL EGR system which would be satisfied the EURO-5 regulation are examined. ESC 13 mode was chosen as the primary engine test mode, and the injection timing and fuel quantity were changed to compensate the lost engine performance caused by EGR. The system developed in this study shows that the current EURO-3 engine could satisfy EURO-5 $NO_x$ regulation by applying LPL EGR.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.391-392
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• 2007

In recent, portable information and communication terminals such as a notebook computer, an electronic pocketbook, a hand personal computer(PC) have been regards as the leading role in the coming next generation portable multimedia terminals which have hi-directional wireless data communication capability and can receive information and communication services such as electronic mail, database searching, and electronic shopping at anytime and anyplace. Therefore, in this paper, the circuit is simulated by 0.35um memory process used Current Limit for Boost DC-DC converter. Supply voltage $2.5V{\sim}3.3V$, output voltage 5V, Clock Frequency 1MHz, output current 200mA and line regulation decreased 12.46%.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.3 s.96
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• pp.38-46
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• 1999

Spindle motor current is used to estimate the cutting force indirectly and control the feed rate for the cutting force regulation. The proposed algorithm is implemented to a DSP board based hardware for the industrial application. The software to make POP terminal communicate with the DSP board and POP server is coded under Windows 95 environment. Experiments under varying cutting conditions show that the DSP board recognizes the information of installed cutting tool and cutting conditions delivered from the POP server to use them for the proper control of the feed rate. The cutting force is regulated well during machining of tapered or stepped workpiece and circular shaped workpiece as well.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.1
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• pp.91-98
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• 1999

An integrated ZCS quasi-resonant converter(QRC) for the power factor correction with a single switch is presented in this paper. The power factor correction can be achieved by the discontinuous conduction mode(DCM) operation of the input current. The proposed converter gives the good power factor, low line current harmonics, and tight output regulation. The input current waveform of the prototype designed using design equations shows about 15% of total harmonic distortion at rated condition. Also, the efficiency and power factor can be obtained about 86% and 0.985, respectively, at rated condition. The proposed converter is suitable for a low power level converter with a tightly regulated low output voltage and switching frequency of more than several hundreds kHz.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.675-679
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• 2001

The research is to discuss the current resource recycling and recovery policy, which was enacted by Environmental Protection Administrative (EPA) in Taiwan. For the past few years, the solid waste generated in Taiwan has greatly increased about 5 % per year. In addition to the construction of landfill sites and incineration plants, 4 R techniques (Reduction, Reuse, Recycle and Recovery) were also publicized among the citizens and then promulgated to furthermore manage these increased solid waste. Although the regulations have been carried out to a great success, they still need to be revised and updated since solid waste contains varieties of different materials. Therefore, this research discusses the current regulation and makes suggestion for future regulation revision. From the results of this study, energy recovery was suggested to be emphasized in the regulation. Energy could be recovered from materials such as waste tires, and all kinds of plastic containers. Waste tires and most of the plastic containers made of hydrocarbon species, which contains great heating values, should be considered as one of the alternatives for the resource recycling.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.66 no.2
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• pp.63-68
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• 2017

This paper proposes a new non-isolated DC conversion circuit topology of the voltage source coupled inductor series resonant high-frequency PFM controlled boost chopper type DC-DC power converter using two in one IGBT power module, which can efficiently operate under a principle of zero current soft switching for wide output regulation voltage setting ranges and wide fluctuation of the input DC side voltage as well as the load variation ranges. Its steady state operating principle and the output voltage regulation characteristics in the open-loop-based output voltage control scheme without PI controller loop are described and evaluated from theoretical and experimented viewpoints. Finally, in this paper the computer-aided simulation steady-state analysis and the experimental results are presented in order to prove the effectiveness and the validity of voltage regulation characteristics of the proposed series resonant zero current soft switching boost chopper type DC-DC power converter circuit using IGBTs which is based on simple pulse frequency modulation strategy more than, 20kHz.

• Journal of Internet Computing and Services
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• v.18 no.6
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• pp.137-144
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• 2017

A variety of customized marketing strategies are being implemented in the telecommunications market, including the offering of gifts to consumers, as competition in the market is being restructured with the focus on bundled products. However, the Korea Communications Commission (KCC) has recently imposed fines for user discrimination on telecommunication carriers whose marketing strategies have included the award of excessive prizes. In that regard, various issues related to the suitability and appropriate limit of the current gift regulation in the telecommunications market have been raised. Since the Fair Trade Commission, which had a similar scheme to that of the KCC, abolished the regulation on gifts in July 2016, disputes have arisen as to whether the current regulation on gifts is practically effective from the perspective of consumer benefit. In other words, discussions on the rationality of the theoretical and empirical grounds for the regulation on gifts only in the telecommunication market but not in other commodities markets have begun. As such, this study aims to empirically analyze the suitability of the current regulation on gifts in the domestic telecommunications market under the new competitive environment centered on bundled products, and to seek the rational improvement of, and infer the implications for, the regulation on gifts in the telecommunications market based on the results of the analysis.

• Biomolecules & Therapeutics
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• v.17 no.2
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• pp.125-132
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• 2009

Calbindin-$D_{9k}$ (CaBP-9k), a cytosolic calcium-binding protein, is expressed in a variety of tissues, i.e., the duodenum, uterus, placenta, kidney and pituitary gland. Duodenal CaBP-9k is involved in intestinal calcium absorption, and is regulated at transcriptional and post-transcriptional levels by 1,25-dihydroxyvitamin D3, the hormonal form of vitamin D, and glucocorticoids (GCs). Uterine CaBP-9k has been implicated in the regulation of myometrial action(s) through modulation of intracellular calcium, and steroid hormones appear to be the main regulators in its uterine and placental regulation. Because phenotypes of CaBP-9k-null mice appear to be normal, other calcium-transporter genes may compensate for its gene deletion and physiological function in knockout mice. Previous studies indicate that CaBP-9k may be controlled in a tissue-specific fashion. In this review, we summarize the current information on calcium homeostasis related to CaBP-9k gene regulation by GCs, vitamin D and its receptors, and its molecular regulatory mechanism. In addition, we present related data from our current research.