• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.4
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• pp.653-659
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• 2015

In the last few years, the regulations for efficiency grade of the three phase induction motor are internationally being discussed and upgraded for the protection of environment and energy saving. So the efficiency improvement and the reliable test result are essential to determine the premium grade three phase induction motor. While a study on developing the efficiency motor is active, there is little research about the guarantee for efficiency. So in this paper, the dispersion characteristic of the efficiency is studied using uncertainty theory for the three phase induction motor to improve the reliability of efficiency. The values such as input voltage, current, speed, torque were obtained by loss separation method to evaluate the uncertainty. From the result, it was known that the important loss factor could affect the uncertainty is the stray loss.

• BMB Reports
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• v.29 no.6
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• pp.513-518
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• 1996

A soluble protein from Saccharomyces cerevisiae specifically provides protection against a thiolcontaining oxidation system but not against an oxidation system without thiol. This 25-kDa protein was thus named thiol-dependent protector protein (TPP). The role of TPP in the cellular defense against oxidative stress was investigated in Escherichia coli containing an expression vector with a yeast genomic DNA fragment that encodes TPP (strain YP) and a mutant in which the catalytically essential amino acid in the active site of TPP (Cys-47) has been replaced with alanine by site-directed mutagenesis (strain YPC47A). There was a distinct difference between these two strains in regard to viability, modulation of activities of superoxide dismutase and catalase, and the oxidative damage of DNA upon exposure to menadione. These results suggest that TPP may play a direct role in the cellular defense against oxidative stress by functioning as an antioxidant protein.

• Journal of Ginseng Research
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• v.42 no.3
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• pp.356-360
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• 2018

The fermentation of medicinal herbs facilitated by microbes is assumed to exert promising therapeutic efficacy on the absorption, bioavailability, and pharmacological effects by speeding up the making or conversion of active constituents into their metabolites. We examined the cardioprotective potential of fermented ginseng, GBCK25, against high-fat diet (HFD)-induced metabolic and functional illnesses as following the essential analysis such as electrocardiographic parameters, alterations of body and organ weights, and echocardiographic studies. The results exhibited that body weights were significantly reduced and the gain of different organ weights were partly eased by GBCK25 treatment. Echocardiography results proposed the amelioration of heart function through normalized levels of left ventricle systolic pressure, ejection fraction, and fractional shortening. These outcomes deliver straight confirmation that GBCK25 could be a potential nutraceutical source for the relief of HFD-induced obesity mediated cardiac dysfunctions.

• Journal of Digital Convergence
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• v.10 no.7
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• pp.41-58
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• 2012

Although the social media plays leading role in the change the political, economic, social and cultural environment in all fields, it is not really understanded the overall management of social media in society. With understandings on the influence of social media, the purpose of this study is to investigate the characteristics of social media and to provide some suggestion to make use effectively of social media in society. To achieve th purpose of this study, the responsibility and the effort of government was examined. As a result, the Social Media Strategy Broad (tentative title 'Social Media Committee') suggests to protection of the users' rights and active support of the current utilization. This study is expected to show the meaningful implication of social media strategy and standard of the social media utilization in policy, education etc.

• Korean Parent-Child Health Journal
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• v.5 no.1
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• pp.24-37
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• 2002

The purpose of this study is to investigate the level of perceived self-esteem and maternal caretaking behaviors of college students. Data were collected through self-report questionnaires in which maternal caretaking behaviors and self-esteem were included. This study chose 293 students studying at universities and a college in Busan and a college in Taebaek as subjects. The data were analyzed by the SPSS program. The results were as follows ; 1. The mean score of the subjects on self-esteem was 29.6(Range=10-40). 2. The mean score of the subjects on maternal caretaking behaviors was 82.7(Range=22-110). The mean scores of subsets on the maternal caretaking behaviors were as follows ; achievement(4.03), affection(3.86), rational direction(3.79), active participation (3.60), consistent restriction(3.59), authoritative control(3.49) and over-protection(3.28). 3. The level of maternal caretaking behavior revealed some difference according to the students' gender and their mothers' academic career. 4. The level of self-esteem was positively correlated to the level of maternal caretaking behaviors in subjects. In conclusion, the above findings indicate that mothers' positive pattern of maternal caretaking behaviors are closely related to the students' higher self-esteem.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.132-139
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• 2010

The river technology of Japan was highly developed and achieved much result in flood protection, water use and the environment. Nowadays, the function which is requested to the river is changes because the society changes from growth to maturity. In this study, we suggest the functions of the river in the maturity society about future welfare, medical care and education based on field research of case study. In this research, we pay attention to the functions related with culture, one) function of healing, mental stress improvement and life, two) function of landscape, education and recreation. And this paper proposed the usage of the river where adopt to the times, a function and the value of "the river as the space". We made a questionnaire to 187 river managers, and 90% of answers wear positive for use the river as the medical aspect, health and the welfare. Furthermore, based on research result of hospitals and welfare facilities which used a river for their activities, we suggest to develop and use the river walk, to design a city and rivers as one, and to use many facilities which are located on river front more active, those are improve the new river functions.

• Proceedings of the KIEE Conference
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• summer
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• pp.1477-1479
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• 2004

Increasing numbers of photovoltaic arrays are being connected to the power utility through the power conditioning systems (PCS). This has raised potential problems of network protection. If, due to the action of the PCS, the local network voltage and frequency remain within regulatory limits when the utility is disconnected, then islanding is said to occur. In this paper, the representative methods to prevent the islanding are described and a PSIM-based model and analysis of the reactive power variation (RPV) method are presented. A novel phase detector using the all-pass filter and digital phase locked loop (DPLL) is proposed especially for the single-phase PCS. Finally, this paper provides the simulation and experimental results with a single-phase 3kW prototype PCS. Islanding test method of IEEE Std. 929-2000 was performed for verification.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.55-57
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• 2007

A Power control and Distribution Unit (PCDU) plays roles of protection of battery against overcharge by active control of solar array generated power, distribution of unregulated electrical power via controlled outlets to bus and instrument units, distribution of regulated electrical power to selected bus and instrument units, and provision of status monitoring and telecommand interface allowing the system and ground operate the power system, evaluate its performance and initiate appropriate countermeasures in case of abnormal conditions. In this work, we perform the preliminary design of a PCDU for the small Low Earth Orbit (LEO) Satellite applications. The main constitutes of the PCDU are the battery interface module, solar array regulators with maximum power point tracking (MPPT) technology, heater power distribution modules, internal converter modules for regulated bus voltage generation, power distribution modules of unregulated and regulated primary bus, and instrument power distribution modules.

• Journal of Microbiology and Biotechnology
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• v.11 no.5
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• pp.838-844
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• 2001

The enzyme Fuc aldolase from Methanococcus jannaschii that catalyzes the aldol condensation of DHAP and L-lactaldehyde to give fuculose-1-phosphate was inactivated by DEP. The inactivation was pseudo first-order in the enzyme and DEP, which was biphasic. A pseudo second-order rate constant of 120$M^{-1}min^{-1}$ was obtained at pH 6.0 and $25{\circ}C$. Quantifying the increase in absorbance at 240nm showed that four histidine residues per subunit were modified during the nearly complete inactivation. The statistical analysis and the time course of the modification suggested that two or three histidine residues were essential for activity. The rate of inactivation was dependent on the pH, and the pH inactivation data implied the involvement of the amino acid residue with a $pK_a$ value of 5.7. Fuc aldolase was protected against DEP inactivation by DHAP, indicating that the histidine residues were located at the active site of Fuc aldolase. DL-Glyceraldehyde, as an alternative substrate to L-lactaldehyde, showed no specific protection for the Fuc aldolase.

• Journal of Power Electronics
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• v.11 no.3
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• pp.271-278
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• 2011

This paper presents a LLC resonant controller IC for secondary side control without external active devices to achieve low profile and low cost LED back light units. A gate driving transformer is adopted to isolate the primary side and the secondary side instead of an opto-coupler. A new integrated dimming circuitry is proposed to improve the dynamic current control characteristic and the current density of a LED for the brightness modulation of a large screen LCD. A dual-slope clock generator is proposed to overcome the frequency error due to the under shoot in conventional approaches. This chip is fabricated using 0.35 ${\mu}m$ BCD technology and the die size is $2{\times}2\;mm^2$. The frequency range of the clock generator is from 50 kHz to 500 kHz and the range of the dead time is from 50 ns to 2.2 ${\mu}s$. The efficiency of the LED driving circuit is 97 % and the current consumption is 40 mA for a 100 kHz operation frequency from a 15 V supply voltage.