• Journal of Electrical Engineering and Technology
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• v.10 no.5
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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).

• The Journal of the Korea Contents Association
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• v.12 no.9
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• pp.27-39
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• 2012

The purpose of this study is to develop and suggest u-project teaching and learning model in order to effectively practice multidisciplinary and practical green growth conversion education, In order to achieve the purpose of study, the researchers conducted surveys to middle and high school teachers (189), teachers-to-be (285), and middle school students (358) on green growth perception, and analyzed relation between the ten green growth strategic directions and the 2007 and 2009 curricula. The extraction of the teaching and learning contents for the ubiquitous green growth conversion education and the development of a TUGG (Teaching Ubiquitously for Green Growth) model that is suitable for middle school application were also pursued. This study will increase the understanding of the necessity and propriety of green growth and also promote multidisciplinary and practical green growth conversion education.

• Nuclear Engineering and Technology
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• v.55 no.10
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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.

• The Journal of Korean Medical History
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• v.23 no.2
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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.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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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.

• The Journal of Korean Association of Computer Education
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• v.9 no.1
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• pp.97-106
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• 2006

In the next-generation Internet backbone network, DWDM technology was appeared as an alternative to solve circuit shortage of existing TDM-based Internet. In this DWDM Network, it is inevitable to consider wavelength-conversion function as well as RWA in case of setting up connection for the efficient use of resources and customer satisfaction. This study is to describe an efficient strategy for the wavelength-conversion function with a limited range and for the use of a wavelength converter with the selected node, and to verify the optimum use of a wavelength converter through the performance test.

• Journal of Broadcast Engineering
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• v.24 no.7
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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%.

• Journal of the Korean Dietetic Association
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• v.24 no.3
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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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• v.40 no.4
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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.

• Journal of Digital Convergence
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• v.15 no.1
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• pp.393-401
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• 2017

This article aims to suggest a principle frame and direction for the development of the character education program using Maumgram. Maumgram is said to clearly illustrate step-by-step structures of character education, for which the human mind is classified as four types(indulged type, rage-type, competition type, selfishness type) on the basis of the existing analytical psychology and Yogacara Thought. The design of the mind type program is composed of three steps. The first step is the 'discovery' step to awaken the cause of self-consciousness through observation, and the second is the 'conversion' step. Learning process to control the negative desires in a positive desire, and the third is the 'relationship'-oriented step to promote a sense of community with other people.