• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1103-1105
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• 2002

A conventional AC-DC boost converter has much variation of input current as more increased the load or output voltage by the hysterical control method that is comparing area of current pulse by using PWM method and integration to sinusoidal input current. To improve the problems. in this paper, we propose the single-phase voltage doubler AC-DC converter circuit using the capacitor for boost:confirm characteristics of normal and transition state by using simulation, be stabilized voltage of doubler capacitor for boost, and Identify to get the sinusoidal input current with unity power factor.

• Progress in Superconductivity and Cryogenics
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• v.15 no.1
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• pp.19-24
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• 2013

In this paper, the Superconductor flywheel energy storage system (SFESS) was used for the load frequency control (LFC) of an interconnected 2 area power system. The robust SFESS controller using quantitative feedback theory (QFT) was designed to improve control performance in spite of parameter uncertainty and unexpected disturbances. An overlapping decomposition method was applied to simplify SFESS controller design for the interconnected 2 area power system. The model for simulation of the interconnected 2 area power system included the reheat steam turbine, governor, boiler dynamics and nonlinearity such as governor deadband and generation rate constraint (GRC). To verify robust performance of proposed SFESS controller, dynamic simulation was performed under various disturbances and parameters variation of power system. The results showed that the proposed SFESS controller was more robust than the conventional method.

• KOMUNHWA
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• no.37
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• pp.41-57
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• 1990

• Journal of Environmental Science International
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• v.17 no.1
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• pp.29-36
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• 2008

A large amount of $2.1{\times}10^6m^3$ of polluted sediment was dredged from the Masan Bay and deposited in Gapo confined area, Masan, Korea. The six representative sediments were obtained and analyzed for issue components. The data was discussed with the species of benthos and their distribution. It was judged that toxicological effects of sediment analyzed ranged from ERL to ERM with copper and zinc, and ERL with cadmium, chrome, lead and nickel by the Adverse Biological Effects. The dredging index (DI) of sediments stabilized for 10 years since dumping the confined site was calculated and compared with the DI values of dredged sediment itself. DI values decreased from 0.67 to $0.07{\sim}0.18$, which reflects DI value less than 0.2 is good for benthos in the sediment by the natural recovery of dredged materials. The ecological recovery was confirmed in this confined area as a habitat of benthic organisms.

• Bulletin of the Korean Chemical Society
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• v.24 no.8
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• pp.1203-1206
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• 2003

Analysis of health-related microbes called probiotics was performed by capillary electrophoresis. A rapid and easy characterization for two important probiotics, Saccharomyces cerevisiae and Enterococcus feacalis, was obtained in the running buffer containing poly(ethylene oxide). Quantitation of probiotic (Saccharomyces cerevisiae) shows a good linearity between the peak area versus the concentration of microbe. From the comparison of electropherograms of antidiarrhea, it was found that capillary electrophoresis could be employed for the quality control and quality assurance for the production of a medicine containing the probiotics.

• Asia pacific journal of information systems
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• v.26 no.2
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• pp.290-298
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• 2016

Human cognition and decision-making related to information systems (IS) is a major area of interest in IS research. Among these areas, cognitive bias rooted in behavioral economics is gaining considerable attention from researchers. In the present study, we identify the role of cognitive biases and discuss how they shape the information security behavior. We also seek research opportunities to provide directions and implications for future research.

• Journal of Korea Water Resources Association
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• v.45 no.11
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• pp.1093-1105
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• 2012

In this study, the simulations and analyses of flood flow due to a river inundation in a coastal urban area are carried out using a two-dimensional finite volume model with well-balanced HLLC scheme. The target area is a coastal urban area around Gohyun river which is located at Geoje city in Kyungnam province and was extremely damaged due to the heavy rainfall during the period of the typhoon "Maemi" in September 2003. For the purpose of the verification of the numerical model applied in this study, the simulated results are compared and analyzed with the inundation traces. In addition, the flood flow in an urban area is simulated and analyzed according to the scenarios of inflow variation due to the increase and decrease of the intensity of the heavy rainfall, which.

• Korean journal of food and cookery science
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• v.30 no.5
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• pp.650-662
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• 2014

This study was conducted to identify middle school students' caffeine intake from their favorite foods containing caffeine as well as several factors related to their intake. The objects of the investigation were 369 middle school students in the urban area of Changwon-si and 358 middle school students in the rural area of Haman-gun. The average height was 162.3cm, average weight was 52.3 kg and average BMI was 19.8. The food habit score was generally positive at an average of 3.37. The food habit scores of rural area students were higher than those of urban area students (p<.05). The average stress score was somewhat low at 2.82. The stress index for rural students was lower than that of urban students (p<.01). The recognition of caffeine in favorite foods was 8.12 out of a 12 point scale. The average nutritional knowledge score regarding caffeine was very low at 3.08 out of a 10 point scale. The main reason for selecting favorite foods was 'taste'. The percentage of students who don't check food labels was 49.1%. 'House' was the main location while 'good taste' was the biggest reason for eating caffeine-containing foods. The main side effect of caffeine intake was 'nausea'. The average daily caffeine intake for all subjects was 26.96 mg, with the urban students averaging 27.90 mg and the rural students averaging 25.99 mg. The correlations between several factors and caffeine intake were examined. Food habit showed a negative correlation with stress score and caffeine intake. Nutritional knowledge and recognition of caffeine had positive correlations with caffeine intake. Hence nutritional education about caffeine should be emphasized to improve students' healthy food habits.

• Journal of the Korean Home Economics Association
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• v.46 no.2
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• pp.25-37
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• 2008

This study has investigated the perception of adults in relation to healthy family to help identify import issues. Gathered information were then incorporated to education programs for the Healthy Family Support Center. For this purpose, a survey was conducted in four cities in Kyungnam during March 2007. The responses of 213subjects have been used for the final analysis. The results of this analysis lead to three major findings. Firstly, the surveyed adults regarded positive interaction and domestic family functions as essential activities in healthy families. Secondly, the participants exhibited a very low knowledge-level of the 'Healthy Family Act', and the Healthy Family Support Center. Finally, the respondents said that they are more likely to specifically participate in educational program and counseling program if it helps them prevent family programs.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.355-358
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• 2005

The electrical characteristics for applying the foundation of the house to the substitutional earth electrode was reviewed fundamentally. In order to measure the earth resistance in the foundation of the house, it was performed to investigate the effect of the electrode arrangements and configurations concerning to grounding methods, and tried to the adequate simulation for comparing those experimental data. The number of steel rods and the ground resistivity were affected to change the earth resistance, but the latter caused the large variation in its resistance compared to the former in this experiment. Since the large surface area in the foundation of the house have contacted the ground usually, it is possible to use the earth electrode substitutionally.