• Journal of Electrical Engineering and Technology
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• 제10권5호
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• pp.1921-1929
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• 2015

The smart substation is the heart of a transmission system, which is particularly emphasized as the most significant composition of smart grids in China. In order to assess the functionality performance of substation technologies, this paper presents methods used to identify the most promising solutions for smart substation design and to evaluate the technical levels of available technologies. The multi-index optimization model is presented to address the issue of smart substation planning. A mathematical model of the planning decision problem is established with multiple objectives consisting of economic, reliability, and green key indices, and many kinds of concerns including physical and environmentally friendly operations are formulated as a set of constraints. With respect to the assessment of the technical level regarding integration of advanced technologies into a substation, a modified grey whitenization weight function is adopted to structure a novel grey clustering method. The proposed grey clustering approach is used to overcome the difficulty of insufficient quantitative assessment capacity for traditional methods. The evaluation of technical effects provides the classification definition for the development phase and the maturity level of the smart substation. The effectiveness of the proposed approaches in planning decision-making and evaluation of construction efforts is demonstrated with case studies involving the actual smart substation projects of Wenchongkou substation in China Southern Power Grid (CSG) and Mengzi substation in State Grid Corporation of China (SGCC).

• 한국콘텐츠학회논문지
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• 제12권9호
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• pp.27-39
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• 2012

본 연구는 인문사회과학을 통합하는 간 학문적 실천적 녹색성장 융합 교육을 효과적으로 실시하기 위하여 u-프로젝트 교수 학습 모형을 개발 제시하는데 목적이 있다. 연구의 목적을 달성하기 위하여 교사, 예비교사, 중학생을 대상으로 녹색성장에 대한 인식수준 조사, 녹색성장 10대 정책방향과 중등/사범대학 교육과정 간 연관성 분석, 녹색성장 융합교육을 위한 교수 학습 내용요소를 추출하였다. 그리고 녹색성장 u-프로젝트 교수 학습의 핵심활동 요소와 절차를 구안한 후 중등학교 상황에 적용하기 용이하도록 교수 학습의 세부 진행모형을 개발하였다. 본 연구에서 개발된 모형을 통해 녹색성장의 필요성과 타당성에 대한 이해를 증진시키는 것과 동시에 인문사회과학을 통합하는 간 학문적 실천적 교육이 가능할 것으로 예상된다.

• Nuclear Engineering and Technology
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• 제55권10호
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• pp.3775-3786
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• 2023

Mixing Vane Grid (MVG) is one of the most important structures in fuel assembly due to its high performance in mixing the coolant and ultimately increasing Critical Heat Flux (CHF), which avoids the temperature rising suddenly of fuel rods. To evaluate the mixing performance of the MVG, a Total Diffusion Coefficient (TDC) mixing coefficient is defined in the subchannel analysis code. Conventionally, the TDC of the spacer grid is obtained from the combination of experiments and subchannel analysis. However, the processing of obtaining and determine a reasonable TDC is much challenging, it is affected by boundary conditions and MVG geometries. In is difficult to perform all the large and costing rod bundle tests. In this paper, the CFD method was applied in TDC analysis. A typical 5 × 5 MVG was simulated and validated to estimate the mixing performance of the MVG. The subchannel code was used to calculate the TDC. Firstly, the CFD method was validated from the aspect of pressure drop and lateral temperature distribution in the subchannels. Then the effect of boundary conditions including the inlet temperature, inlet velocities, heat flux ratio between hot and cold rods and the arrangement of hot and cold rods on MVG mixing and TDC were studied. The geometric effects on mixing are also carried out in this paper. The effect of vane pattern on mixing was investigated to determine which one is the best to represent the grid's mixing performance.

• 한국의사학회지
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• 제23권2호
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• pp.15-22
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• 2010

Currently, in Korea, all lengths are written in "meter" unit, and the non-statutory measuring units are banned for use. However, in some fields, traditional measuring units are widely used with necessary modifications, and people in such fields raise varying arguments on conversion to "meter" unit. This research examines traditional measuring units from historical and cultural viewpoints, and provides suggestions on how to improve consistency and standardization for more accurate and effective exchangeof scientific opinions.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2012년도 춘계학술발표회 논문집
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• pp.227-228
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• 2012

In interfaces between carbon black or Pt and FTO glass in dye-sensitized solar cell counter electrodes, a marginal resistant channel for electrons, we tried to improve the connection by modifying the sintering process. A stepwise sintering process for carbon black and Pt counter electrodes was applied and its effect on power conversion efficiency was studied. Power conversion efficiencies of built-in DSSC made by a one-step sintering process with carbon black and Pt counter electrodes were about 5.01% and 5.02%, respectively. Cells made with the stepwise sintering process were 5.96% and 6.21%, respectively, indicating an 20% improvement. Fill factor (FF) increased, and it was them main reason for the power conversion efficiency improvement. Step wise sintering increased the adhesion of the interface and reduced the film thickness and surface roughness. As a result, the resistivity of the counter electrode and EIS impedance of DSSCs decreased.

• 컴퓨터교육학회논문지
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• 제9권1호
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• pp.97-106
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• 2006

차세대 인터넷 백본망에서 DWDM 기술은 기존의 TDM 기반 인터넷이 가진 회선 부족 문제를 해결하기 위한 대안으로 등장하였다. DWDM 망에서는 자원의 효율적인 사용과 각기 다른 사용자 요구사항을 충족하기 위해 연결 설정시 RWA 문제와 더불어 파장 변환 기능에 대한 고려가 필수적이다. 본 논문에서는 제한된 범위의 파장 변환 기능 및 선택된 노드의 파장변환기 사용에 대한 효율적인 방안에 대해 기술하고, 성능 실험을 통해 최적의 파장변환기 사용을 검증한다.

• 방송공학회논문지
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• 제24권7호
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• pp.1209-1220
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• 2019

The demand for virtual reality (VR) is rapidly increasing. Providing the immersive experience requires much operation and many data to transmit. For example, a 360-degree video (360 video) with at least 4K resolution is needed to offer an immersive experience to users. Moreover, the MPEG-I group defined three degrees of freedom plus (3DoF+), and it requires the transmission of multiview 360 videos simultaneoulsy. This could be a burden for the VR streaming system. Accordingly, in this work, a bitrate-saving method using projection conversion is introduced, along with experimental results for streaming 3DoF+ 360 video. The results show that projection conversion of 360 video with 360lib shows a Bjontegaard delta bitrate gain of as much as 11.4%.

• 대한영양사협회학술지
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• 제24권3호
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• pp.261-274
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• 2018

The purpose of this study was to compare wage treatment and the employment environment of school foodservice employees before and after conversion to indefinite contract status since September 2012 when the Ordinance on the Appointment of Education Officials (indefinite contract) under the Gangwon Provincial Superintendent of Education was applied as well as to examine the effects of wage treatment and the employment environment on job stability. The questionnaire survey was conducted from March 31 to April 10, 2017 for school foodservice employees working at 97 schools in Gangwon province. A total of 477 questionnaires were distributed and 470 questionnaires were used for the analysis. Statistical analysis was conducted using SPSS Window Ver.18.0. The detailed results of this study were as follows. First, wage treatment (2.29 vs. 3.16), employment environment (3.45 vs. 4.22) and job stability (1.88 vs. 2.35) revealed significantly positive perceptions after conversion to indefinite contract status compared to before conversion. Second, after analyzing leading factors influencing job stability, it was revealed that wage treatment (before: ${\beta}{\hat{a}}=0.516$, P<0.05; after: ${\beta}{\hat{a}}=0.465$, P<0.05) had a positive (+) effect on job stability, whereas employment environment did not affect job stability. In conclusion, in the context that most school foodservice employees are contract employees, this study is significant in that the changes in the employment policies of the national government and education office were confirmed to have effects on school foodservice employees.

• Journal of Ginseng Research
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• 제40권4호
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• pp.366-374
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• 2016

Background: In this study, we screened and identified an endophyte JG09 having strong biocatalytic activity for ginsenosides from Platycodon grandiflorum, converted ginseng total saponins and ginsenoside monomers, determined the source of minor ginsenosides and the transformation pathways, and calculated the maximum production of minor ginsenosides for the conversion of ginsenoside Rb1 to assess the transformation activity of endophyte JG09. Methods: The transformation of ginseng total saponins and ginsenoside monomers Rb1, Rb2, Rc, Rd, Rg1 into minor ginsenosides F2, C-K and Rh1 using endophyte JG09 isolated by an organizational separation method and Esculin-R2A agar assay, as well as the identification of transformed products via TLC and HPLC, were evaluated. Endophyte JG09 was identified through DNA sequencing and phylogenetic analysis. Results: A total of 32 ${\beta}$-glucosidase-producing endophytes were screened out among the isolated 69 endophytes from P. grandiflorum. An endophyte bacteria JG09 identified as Luteibacter sp. effectively converted protopanaxadiol-type ginsenosides Rb1, Rb2, Rc, Rd into minor ginsenosides F2 and C-K, and converted protopanaxatriol-type ginsenoside Rg1 into minor ginsenoside Rh1. The transformation pathways of major ginsenosides by endophyte JG09 were as follows: $Rb1{\rightarrow}Rd{\rightarrow}F2{\rightarrow}C-K$; $Rb2{\rightarrow}C-O{\rightarrow}C-Y{\rightarrow}C-K$; $Rc{\rightarrow}C-Mc1{\rightarrow}C-Mc{\rightarrow}C-K$; $Rg1{\rightarrow}Rh1$. The maximum production rate of ginsenosides F2 and C-K reached 94.53% and 66.34%, respectively. Conclusion: This is the first report about conversion of major ginsenosides into minor ginsenosides by fermentation with P. grandiflorum endophytes. The results of the study indicate endophyte JG09 would be a potential microbial source for obtaining minor ginsenosides.

• 디지털융복합연구
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• 제15권1호
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• pp.393-401
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• 2017

이 연구는 마음그램을 활용한 인성교육프로그램의 개발을 위한 기초적인 틀과 방향을 제시하는 데에 목적이 있다. '마음그램'이란 기존의 분석심리학 및 유식학의 마음구조를 기반으로 인간의 마음을 네 가지 마음자리(탐닉형, 분노형, 경쟁형, 이기심형)로 유형화하고, 이를 위한 인성교육의 단계적 구조를 알기 쉽게 도식화한 것을 말한다. 마음유형별 프로그램의 설계는 세 단계로 구성된다. 첫 번째 단계는 관찰을 통해 자아의식의 원인을 자각하는 '발견'의 단계이며, 두 번째는 부정적인 욕구를 긍정적인 욕구로 조절하는 학습과정인 '전환'단계, 세 번째는 공동체의식의 함양을 목표로 하는 타자와의 '관계'지향의 단계이다.