• Journal of The Korean Association For Science Education
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• v.35 no.1
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• pp.53-64
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• 2015

This research was performed of high school science classes. These science classes progressed by using Scratch, and surveyed students' perception after finishing each class. This research was conducted of male students who want to choose department of natural science in the next grade. Those classes are consisted of four classes. This study produced a journal, and contained expressions of their thinking and feeling based on experiences during attending classes and projects. Consequently, that journal was analyzed in view of understanding and perception of Scratch using science classes, and it was also included of utilizing Scratch program. Research shows following three conclusions. First, students preferred Scratch using class to general one. They attend more active with high interest, and they felt senses of accomplishment while they make output by themselves. Second, their studies passed through three stages. These are problem perception, problem solving, and producing. Problem solving stage is especially complicated and difficult stage to students. This stage is consisted of Scratch side and Science side. Scratch side has Design and applying process, and Science side has data gathering and analyzing. Students' comprehension of scientific knowledge is increased and is preserved long time through this stage. Last, students had a hard time using Scratch. Because, it is the first time to them to use that program. Therefore, we deemed that they needed to start this kind of experience at lower grade than they are now, such as middle school stage. It is expected that this type of classes are getting more expanded and more populated as a part of students' core ability.

• Journal of the Korean Society for Library and Information Science
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• v.53 no.2
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• pp.117-137
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• 2019

The purpose of this study is to guide the design and operation of maker education programs in school library and to spread them by sharing the maker education program case. For this purpose, we explained the case of maker education of Daegu S high school library and analyzed its significance in terms of users in quantitative and qualitative way. In order to analyze the user's perception of the image and self-efficacy of capacity building of school library maker education, we compared it with the perception of existing school library education programs. In addition, we analyzed whether there is a statistically significant difference in the perception of the maker education according to the grade of the student and the experience of the maker education. The perception of school library maker education was not more positive than the existing school library education program. However, it is noteworthy that students who experienced school library maker education showed a positive image and high level of perception of the self-efficacy of capacity building in both existing school library education and manufacturing education compared to those who did not. These results suggest that school library maker education can improve the overall image of school library education and raise perception of the self-efficacy of capacity building. We hope that this study will contribute to activate school library maker education.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.4
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• pp.437-442
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• 2010

Flow-accelerated corrosion (FAC) leads to thinning of steel pipe walls that are exposed to flowing water or wet steam. From experience, it is seen that FAC damage to piping at fossil and nuclear plants can result in outages that require expensive repairs and can affect plant reliability and safety. CHECWORKS have been utilized in domestic nuclear plants as a predictive tool to assist FAC engineers in planning inspections and evaluating the inspection data so that piping failures caused by FAC can be prevented. However, CHECWORKS may be occasionally ignore local susceptible portions when predicting FAC damage in a group of pipelines after constructing a database for all the secondary side piping in nuclear plants. This paper describes the methodologies that can complement CHECWORKS and the verifications of CHECWORKS prediction results using numerical analysis. FAC susceptible locations determined using CHECWORKS for two pipeline groups of a nuclear plant was compared with determined using the numerical-analysis-based FLUENT.

• Journal of Environmental Science International
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• v.23 no.2
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• pp.157-164
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• 2014

The essential oil obtained by steam distillation from medicinal plants of Cinnamomum cassia and Prunellae Herba. Analysis of essential oils were performed on GC/MS selective detector. Separations were performed fused silica capillary column. The carrier gas was ultra pure helium with a flow of 1 $m{\ell}/min$ and the splitless injector temperature was set as $280^{\circ}C$. The column temperature program was as follows: initial temperature of $70^{\circ}C$ for 4 min, and increased by $2^{\circ}C/min$ 70 to $100^{\circ}C$ (held 2 min), After that the temperature was varied from 100 to $200^{\circ}C$ at $5^{\circ}C/min$ (held 20 min), increase to $280^{\circ}C$ (held 5 min) at $10^{\circ}C/min$, in a total run time of 73 min. Ten volatile flavor components were identified from C. cassia and ten volatile flavor components were identified from Prunellae Herba. Strong inhibition of growth of Vibrio parahaemolyticus was obtained with all doses of C. cassia tested. Moreover, antimicrobial activity of C. cassia occurred in a dose dependant manner.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.12
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• pp.1069-1078
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• 2013

Recently, condensation heat exchangers have been studied for applications to the passive cooling systems of nuclear plants. To design vertical-type condensation heat exchangers in secondary passive cooling systems, TSCON (Thermal Sizing of CONdenser), a thermal sizing program for a condensation heat exchanger, was developed at KAERI (Korea Atomic Energy Research Institute). In this study, the existing condensation heat transfer correlation of TSCON was evaluated using 1,157 collected experimental data points from the heat exchanger of a secondary passive cooling system for the case of pure steam condensation. The investigation showed that the Shah correlation, published in 2009, provided the most satisfactory results for the heat transfer coefficient with a mean absolute error of 34.8%. It is suggested that the Shah correlation is appropriate for designing a condensation heat exchanger in TSCON.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.2
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• pp.139-148
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• 2013

In this study, an ejector was designed to recirculate the anodic off-gas of SOFC, and a parametric study of the system performance was conducted at various ejector entrainment ratios. Aspen Plus, a chemical engineering program, was used to calculate the operational conditions of the ejector. To minimize the calculation load of the CFD and to ensure the global optimum, a genetic algorithm and Kriging model were used for the optimization. The optimization results showed that the dominant design variables of the sonic ejector are the throat diameter and the first flow nozzle position. The designed ejector has enough flexibility for different operating conditions of a 1-kW SOFC system. When the ejector was applied to the SOFC, it reduced 56% of the steam and 8.4% of the fuel compared to the reference case.

• Nuclear Engineering and Technology
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• v.27 no.3
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• pp.403-417
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• 1995

The upturn of Korean nuclear power program can be considered to have started in early 70's while future plants for the construction of new nuclear power plane virtually came to a halt in United States. It is projected that power plant systems from combination of nuclear and coal fired types might shift to all coal fired type, considering the current trend of construction on the new Plants in the United States. However, with the depletion of natural resources, it is desirable to understand the utilization of two competitive utility technologies in terms of invested energy. Presented in this paper is a comparison between two systems, nuclear power plant and coal fired steam power plant in terms of energy investment. The method of comparison is Net Energy Analysis (NEA). In doing so, Input-Output Analysis (IOA) among industries and commodities is done. Using these information, net energy ratios are calculated and compared. NEA is conducted for power plants in U. S. because the availability of necessary data are limited in Korea. Although NEA does not offer conclusive solution, this method can work as a screening process in decision making. When considering energy systems, results from such analysis can be used as a general guideline.

• Korean Journal of Community Nutrition
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• v.16 no.1
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• pp.98-112
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• 2011

This study aimed to suggest a 1300 scale of a middle school foodservice facility floor plan which was compliant to the principle of HACCP, as well as ensuring food and work safety, and the flow of personnel and food materials. which consisted of 46 nutrition teachers and 6 experts, responded with a questionnaire on the relationship of functional area and space. Using their opinions, key principles for the design of the facility were single direction movement of food materials, customers and workers; minimization of the cross-contamination through the separation of functional space; and securement of customer-focused efficiency; staff-centered convenience and efficiency; and work and food safety. After the completion of an adjacency diagram, bubble diagram and program statement, the functional areas of a 1300 scale middle school food-service facility were allocated as follows: $9.9\;m^2$ for the receiving area, $56.1\;m^2$ for the pre-preparation area, $10.5\;m^2$ for the food storage area, $6.0\;m^2$ for the supplies storage area, $97.8\;m^2$ for the cooking area, $33.6\;m^2$ for the service area, $52.5\;m^2$ for dish washing area, cafeteria $410.5\;m^2$, $4.5\;m^2$ for the front room, for a total of $725.8\;m^2$. Expert groups have pointed to limitations within this model as there are no windows in the office for the influx of fresh outside air and a need for the straight line installation of steam-jacket and frying kettles on the sides of windows. This study can be useful as the guidelines for estimating the investment cost of the facility and placing the placement of functional areas and equipment in the renovation of the facility. It can be also useful data for a methodology of foodservice facility design.

• Journal of the Korean Society for Library and Information Science
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• v.52 no.4
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• pp.137-161
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• 2018

The purpose of this study is identify the awareness and opinion of school librarians and teacher-librarians on the school library maker space. To do this, we used a semi-structured questionnaire to interview and analyzed in-depth telephone interviews of 7 school library professionals qualitatively. The recognition of makerspaces, the necessity of transforming school libraries into makerspaces and maker education, preparations and difficulties of implementation were investigated through the interview. As the result of interview analysis, school library professionals recognized that school library makerspace is essential to fulfill the users needs and important to enhance the library services. Also, school library professionals felt that it is desirable for the school library to function as a center for the in-school maker education program. Other important issues of the makerspace in school library were also identified. The key findings of this study are expected to be used as a momentum to activate the maker education centering on the school library.

• Journal of the Korean Society of Safety
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• v.36 no.3
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• pp.74-80
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• 2021

Korea Atomic Energy Research Institute (KAERI) has been operating an integral effects test facility, the Advanced Thermal-Hydraulic Test Loop for Accident Simulation (ATLAS), according to APR1400 for transient experimental and design basis accident simulation. Moreover, based on the experimental data, the domestic standard problem (DSP) program has been conducted in Korea to validate system codes. Recently, through DSP-05, the performance of the passive auxiliary feedwater system (PAFS) in the event of multiple steam generator tube rupture (MSGTR) has been analyzed. However, some errors exist in the reference input model distributed for DSP-05. Furthermore, the calculation results of the heat loss correlation for the secondary system presented in the technical report of the reference indicate that a large difference is present in heat loss from the target value. Thus, in this study, the reference model is corrected using the geometric information from the design report and drawings of ATLAS. Additionally, a new heat loss correlation is suggested by fitting the results of the heat loss tests. Herein, MSGTR-PAFS accident analysis is performed using MARS-KS 1.5 with the improved model. The steady-state calculation results do not significantly differ from the experimental values, and the overall physical behavior of the transient state is properly predicted. Particularly, the predicted operating time of PAFS is similar to the experimental results obtained by the modified model. Furthermore, the operating time of PAFS varies according to the heat loss of the secondary system, and the sensitivity analysis results for the heat loss of the secondary system are presented.