• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.262-263
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• 2008

The Metal-Insulator-Silicon (MIS) capacitors with $SiO_2$ and high-k dielectric were investigated. The high-k dielectrics were obtained by atomic layer deposit (ALD) system. The electrical characteristics were investigated by measuring the current-voltage (I-V) characteristics. The conduction mechanisms were analyzed by using the Fowler-Nordheim (FN) plot and Direct Tunneling (DT) plot. As a result, the MIS capacitors with high-k dielectrics have lower leakage current densities than conventional tunnel-barrier with $SiO_2$ dielectrics.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.232-238
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• 2016

This paper presents protection techniques against electric shock in low voltage DC(direct current) grounding systems depending on the analysis of earth fault current paths. Firstly, the comparison between alternating current and direct current on human was conducted, and current threshold values for each current path and for long duration were analyzed. Secondly, the analyses of the earth fault current flows were performed depending on the grounding types and earth fault conditions. Lastly, based on these analyses, adequate protection measures of electric shock depending on low voltage DC grounding types were provided.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.227-231
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• 2016

Electrical disasters have not been greatly reduced despite continuous prevention efforts until now. However, the smart distribution board which can be measured information about general electrical condition such as current, voltage, power, power factor etc. and electrical safety condition such as over-current, leakage current, arc etc. and communicated analysis information about electrical condition with server will be helpful for the prevention of electrical disasters through real-time surveillance and data analysis under smart grids based on the two-way communication. In this paper, the proposal standard of smart distribution board for electrical safety is suggested about the structure, functional requirements of compositions, communication, security and so on.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.1
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• pp.188-195
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• 2015

This paper presents measurement error reduction technique of touch and step voltage of grounding system based on numerical analysis. When measuring touch and step voltage of grounding system, auxiliary current probes should be located at suitable places. However, the auxiliary probes can not be located at suitable places in such cases as there are buildings and pavements. Therefore, in this paper, we provided measurement error reduction technique of touch and step voltage of grounding system according to the positions of auxiliary probes and angle between auxiliary probes. Also, measurement error analyses of touch and step voltage of grounding system have been conducted using more than one current probe. Based on these analyses, recommended positions of auxiliary probes within allowable measurement errors were presented.

• Journal of Environmental Science International
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• v.20 no.6
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• pp.775-782
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• 2011

The purpose of this study was to evaluate the basic unit of irrigation water on golf courses in Jeju Island. The amounts of rainwater and groundwater used on 20 golf courses have been monitored for this study. The characteristics of rainwater and groundwater from the selected 20 golf courses were analyzed based on the existing data that had been collected for three consecutive years from 2006 to 2009. The range of monthly irrigation water (groundwater + rainwater) used was about $13,200\sim55,600\;m^3$/month, with average of $36,600\;m^3$/month. In the respects of the amount of annual water used, groundwater was recorded as $163,500\;m^3$/year, and rainwater was recorded as $275,400\;m^3$/year. Thus, the total annual irrigation water used was approximately $439,000\;m^3$/year. The correlation (R2) between golf course lot size and average amount of monthly irrigation water used was 0.65, and the monthly basic unit per golf course area ($1,000\;m^2$) was calculated as $60\;m^3$.

• Proceedings of the Korean Society of Computer Information Conference
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• 2011.01a
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• pp.171-172
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• 2011

본 논문에서는 사람들의 관심사를 충족시킬 주제로, 소셜 네트워크(SNS)를 활성화 하여 다자간의 대화를 통한 비즈니스 마케팅을 유도하며 기존의 블로그 형식의 커뮤니티와 쇼핑몰의 형태를 결합한 신개념 네트워크를 제안하고 구현한다. 소셜 네트워크를 활성화 시키고, 패션이라는 주제로 사람들의 개성을 살릴 수 있는 아이템을 선정. 각자의 특성이 담긴 "아바타"를 제작, 본 논문 내에서 각자가 특성이 담긴 패셔니스타가 될 수 있는 공간이 된다. 실제 의류, 소품과 제법 유사하게 만든 이미지를 나와의 신체 비율이 비슷한 아바타에 직접 피팅을 시킬 수 있으며 자신이 직접 입어보지 않고, 시간과 공간의 제약을 받지 않는 것이 특징이다. 다자간의 실시간 커뮤니케이션을 통해 네트워킹도 활성화 될 뿐더러 기업과의 연계를 통해 구매로까지 이어질 수 있는 공간을 만든다.

• Korean Journal of Occupational Health Nursing
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• v.29 no.4
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• pp.325-332
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• 2020

Purpose: This study aimed to identify influencing factors on the stress of employees in large corporations by examining relationships between self-esteem, emotional intelligence, and mindfulness. Methods: A hundred and sixty four employees from large corporations completed self-reporting questionnaires during November and December, 2019. The collected data were analyzed with SPSS/WIN 22.0 using descriptive statistics, the t-test, ANOVA, correlation, and multiple regression analysis. Results: The scores were 2.96±0.40 for "self-esteem", 3.56±0.61 for "emotional intelligence", 4.01±0.04 for "mindfulness", and 2.21±0.79 for "stress response". A regression analysis identifying factors affecting the stress response of employees in large corporations showed that "mindfulness" was the most significant factor (β=-.58, p<.001), followed by "emotional intelligence" (β=-.21, p=.005) and "self-esteem" (β=-.16, p=.009). The explanatory power of these variables for the stress response of employees in large corporations was 48%. Conclusion: Our findings suggest that self-esteem, emotional intelligence, and mindfulness are significantly related to employees' stress response in large corporations. Therefore, stress response management programs should be developed to improve self-esteem, emotional intelligence, and mindfulness.

• Journal of Korea Foundry Society
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• v.2 no.1
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• pp.2-11
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• 1982

In order to investigate the relationship between the thermal characteristics of the various molds as green sand mold, dry sand mold, $CO_2$ mold and shell mold, and the solidification characteristics of molten metal, the thermal analysis of rarious molds and melt were performed. The structure of Al-Castings was a/so observed. Results obtained in this experiment were as follows : 1) The heating rate of the molds was increased in the order of green sand mold, $CO_2$ mold, dry sand mold and shell mold, On the other hand the solidification time of the melts was shortened in the order of dry sand mold castings, $CO_2$ mold castings, green sand mold castings and shell mold castings. 2) The arrest temperature period in the heating curve of the green sand mold was resulted from the eraporation of moisture contained in mold, which was transfered to the outer side of the mold. 3) The temperature fluctuation of the melt in the shell mold was considered to be resulted from the combution heat of resin contained in the mold. 4) The amounts of heat absorption of the molds were increased in the order of dry sand mold, $CO_2$ mold, green sand mold and shell mold. 5) The higher the solidification rate was, the longer was its shrinkage pipe and the finer its grain size.

• Journal of the Korean Applied Science and Technology
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• v.12 no.2
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• pp.13-19
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• 1995

Spin finish(SF) for nylon filament was prepared. The influence on the properties of filament obtained by treating the prepared spin finish in this study(SF-2) and foreign-made spin finish(Spinnar N-100) was compared. SF-2 prepared by blending of spindle oil 70g, paraffin wax 10g, glyceryl mono-oleate 5g, POE(6) nonylphenyl ether 4g, POE(10) nonylphenyl ether 4g, POE(10) octylphenyl ether 2g, POE(14) mono-oleate 4g and water 1g was excellent in its characteristics. Some of the properties of Nylon filament treated with SF-2 were better than those treated with Spinnar N-100. Also, optimal physical conditions of nylon filament according to the number of revolution of oil roller were obtained at conditions of 5rpm of number of revolution oil roller, 1.25% of SF-2 oil pick up, and denier 69D.

• Journal of Environmental Science International
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• v.27 no.3
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• pp.167-177
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• 2018

The removal characteristics of As and Se ions from aqueous solution by hexadecyl trimethyl ammonium bromide (HTMAB) modified anthracite (HTMAB-AT) were investigated under various conditions of contact time, pH and temperature. When the pH is 6, the zeta potential value of anthracite (AT) is -24 mV and on the other hand, the zeta potential value of the HTMAB-AT is +44 mV. It can be seen that the overall increase of about 60 mV. Increasing the (+) potential value indicates that the surface of the adsorbent had a stronger positive charge, so adsorption for the anion metal was increased. The isotherm data was well described by Langmuir and Temkin isotherm model. The maximum adsorption capacity was found to be 7.81 and 6.89 mg/g for As and Se ions from the Langmuir isotherm model at 298 K, respectively. The kinetic data was tested using pseudo first and pseudo second order models. The results indicated that adsorption fitted well with the pseudo second order kinetic model. The mechanism of the adsorption process showed that adsorption was dependent on intra particle diffusion model according to two step diffusion. The thermodynamic parameters(${\Delta}G^{\circ}$, ${\Delta}H^{\circ}$, and ${\Delta}S^{\circ}$) were also determined using the equilibrium constant value obtained at different temperatures. The thermodynamic parameters indicated that the adsorption process was physisorption, and also an endothermic and spontaneous process.