• Title/Summary/Keyword: class field

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Application of CFD to Design Procedure of Ammonia Injection System in DeNOx Facilities in a Coal-Fired Power Plant (석탄화력 발전소 탈질설비의 암모니아 분사시스템 설계를 위한 CFD 기법 적용에 관한 연구)

  • Kim, Min-Kyu;Kim, Byeong-Seok;Chung, Hee-Taeg
    • Clean Technology
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    • v.27 no.1
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    • pp.61-68
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    • 2021
  • Selective catalytic reduction (SCR) is widely used as a method of removing nitrogen oxide in large-capacity thermal power generation systems. Uniform mixing of the injected ammonia and the inlet flue gas is very important to the performance of the denitrification reduction process in the catalyst bed. In the present study, a computational analysis technique was applied to the ammonia injection system design process of a denitrification facility. The applied model is the denitrification facility of an 800 MW class coal-fired power plant currently in operation. The flow field to be solved ranges from the inlet of the ammonia injection system to the end of the catalyst bed. The flow was analyzed in the two-dimensional domain assuming incompressible. The steady-state turbulent flow was solved with the commercial software named ANSYS-Fluent. The nozzle arrangement gap and injection flow rate in the ammonia injection system were chosen as the design parameters. A total of four (4) cases were simulated and compared. The root mean square of the NH3/NO molar ratio at the inlet of the catalyst layer was chosen as the optimization parameter and the design of the experiment was used as the base of the optimization algorithm. The case where the nozzle pitch and flow rate were adjusted at the same time was the best in terms of flow uniformity.

The Effects of the Online Learning Using Virtual Reality (VR) Geological Data: Focused on the Geo-Big Data Open Platform (가상현실(VR) 지질자료 개발을 통한 원격수업의 효과 분석: 지오빅데이터 오픈플랫폼 활용을 중심으로)

  • Yoon, Han Do;Kim, Hyoungbum;Kim, Heoungtae
    • Journal of the Korean Society of Earth Science Education
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    • v.15 no.1
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    • pp.47-61
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    • 2022
  • In this study, We developed VR (Virtual Reality) geological resources based on the Geo Big Data of the Big Data platform that provided by the Korea Institute of Geoscience and Mineral Material (KIGAM). So students selected the theme of lessons by using these resources and we operated Remote classes using the materials that developed as to Virtual Reality. Therefore, the geological theme maps provided by the Geo Big Data Open Platform were reconstructed and produced materials were created for Study about Real Korean geological outcrops grounded in Virtual Reality. And Topographic information data was used to produce class materials for Remote classes. Twenty students were selected by Random sampling, and data were collected by conducting a survey including interviews to confirm the change in students' perception of remote classes in virtual reality geological data development and the effect of the classes, so data were analyzed through inductive categorization. The results of this study are as follows. First, students showed positive responses in terms of interest, utilization, and knowledge utilization as taking remote classes for developing geological data in virtual reality geological data. This is the result of showing the adaptability of diverse and flexible learning getting away from a fixed framework by motivating and encouraging students and inducing cooperation for communication. Second, students recognized distance education in the development of Virtual Reality geological data as 'Realistic hands-on learning process', 'Immersive learning process by motivation', and 'Learning process of acquiring knowledge in the field of earth science'.

Identifying Characteristics of Korean Language Learners Enrolled in University-attached Lifelong Learning Institutions in Hong Kong (홍콩의 한국어 학습자 특성 연구 - 홍콩의 대학 부설 평생교육기관 학습자를 대상으로)

  • Lee, Hyun Ju;Lee, Young-Min
    • The Journal of the Korea Contents Association
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    • v.22 no.1
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    • pp.368-379
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    • 2022
  • This study aims to understand the characteristics of Korean language learners and propose appropriate teaching plans for them through a focus group interview with Korean language instructors who had experience in teaching Korean at university-attached institutions in Hong Kong. For this purpose, the investigator interviewed ten instructors who taught Korean for at least five years. Korean language learners in Hong Kong who were in their twenties, but there were diverse age groups, including those in their fifties or older. Their motivations for learning Korean included the Korean Wave and the influence of support from the Continuing Education Fund by the Hong Kong government. Korean language learners in Hong Kong were characterized by active learning desire and effort, continuous learning intention, passive performance in speaking, and sensitivity to the disclosure of private information. Based on these findings, the study proposes to devise teaching and learning methods based on various age groups in a class and teaching methods for speaking that reflect the characteristics of Korean language learners in Hong Kong to teach Korean more effectively. The study is significant as a field study that examines the learning motivations, learning attitudes, and difficulties with Korean study of Korean language learners based on an unprecedented survey of the characteristics of common local Korean learners in Hong Kong.

Development of a modified model for predicting cabbage yield based on soil properties using GIS (GIS를 이용한 토양정보 기반의 배추 생산량 예측 수정모델 개발)

  • Choi, Yeon Oh;Lee, Jaehyeon;Sim, Jae Hoo;Lee, Seung Woo
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.40 no.5
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    • pp.449-456
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    • 2022
  • This study proposes a deep learning algorithm to predict crop yield using GIS (Geographic Information System) to extract soil properties from Soilgrids and soil suitability class maps. The proposed model modified the structure of a published CNN-RNN (Convolutional Neural Network-Recurrent Neural Network) based crop yield prediction model suitable for the domestic crop environment. The existing model has two characteristics. The first is that it replaces the original yield with the average yield of the year, and the second is that it trains the data of the predicted year. The new model uses the original field value to ensure accuracy, and the network structure has been improved so that it can train only with data prior to the year to be predicted. The proposed model predicted the yield per unit area of autumn cabbage for kimchi by region based on weather, soil, soil suitability classes, and yield data from 1980 to 2020. As a result of computing and predicting data for each of the four years from 2018 to 2021, the error amount for the test data set was about 10%, enabling accurate yield prediction, especially in regions with a large proportion of total yield. In addition, both the proposed model and the existing model show that the error gradually decreases as the number of years of training data increases, resulting in improved general-purpose performance as the number of training data increases.

Vegetation Structure of Abies nephrolepis Forest in Mt. Doota and Mt. Cheongok, Gangwon-do, Korea (강원도 두타산과 청옥산 일대 분비나무림의 식생 구조 분석)

  • Shin, Dong-Bin;Oh, Seung-Hwan
    • Korean Journal of Environment and Ecology
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    • v.36 no.4
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    • pp.413-421
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    • 2022
  • This study was conducted to identify the vegetation structure of the Abies nephrolepis forests by analyzing species composition in Mt. Doota and Mt. Cheongok in the Gangwon region with the phytosociological method. In order to perform a field investigation, 18 survey areas with an area of about 400 m2 were set up for the stands where A. nephrolepis grow wild. Communities were classified through TWINSPAN and visualized using DCA (Detrended Correspondence Analysis). Species diversity analysis, importance value analysis, and DBH class analysis were employed to identify the characteristics of each community. As a result, the A. nephrolepis forests in Mt. Doota and Mt. Cheongok have been classified into 4 communities; GroupI, II, III and IV. GroupIis Quercus mongolica-A. nephrolepis competitive forest dominated by Q. mongolica and A. nephrolepis in the order. Group II is A. nephrolepis-Betula ermanii competitive forest dominated by A. nephrolepis, Sorbus commixta, and B. ermanii in the order. Group III is dominated by A. nephrolepis, but is expected to have competition between A. nephrolepis and Q. mongolica in the future due to the mass occurrence of Q. mongolica saplings. A. nephrolepis, S. commixta, and Q. mongolica are the dominant species in Group IV, and A. nephrolepis is the major dominant species in all layers. The species diversity of the A. nephrolepis forests in Mt. Doota and Mt. Cheongok is lower than other A. nephrolepis forests in Mt. Seorak, Maruguem, and Mt. Odae. It is necessary to establish conservation measures and to continuously monitor the A. nephrolepis forests in Mt. Doota and Mt. Cheongokis due to the harsh environment and the competition that may occur between A. nephrolepis and deciduous trees such as Q. mongolica in the future.

An Exploratory Study on the Preparation for the High School Credit System of the Home Economics Education Community through the Analysis of Operation Case of High School Credit System Research School (고교학점제 연구학교 운영 사례 분석을 통한 가정과 교육공동체의 고교학점제 준비 방안에 대한 탐색적 연구)

  • Han, Ju
    • Journal of Korean Home Economics Education Association
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    • v.33 no.2
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    • pp.1-25
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    • 2021
  • The purpose of this paper is to explore ways to prepare for the high school credit system in the home economics educational community through the case of high school credit system research school operation. To this end, the operation process of H high school in Gangwon-do, which operated a high school credit system in 2019, was monitored for 5 months, and surveys and interviews were conducted with students, parents, and teachers to determine the operation of the curriculum. Suggestions based on the case of H high school's operation of the high school credit system for home economics educational community are as follows. Home economics teachers should make active efforts to provide attractive and meaningful home economics lessons to their students by improving instruction and assessment, and implementing a variety of elective courses within the subject of home economics, including collaborative online curricula. Home economics teacher communities and related associations should build a solid network that connects local home economics subject research groups, share information related to curriculum operation, and use it as a channel for disseminating class research results. Home economics teacher training institutions should innovate the curriculum to help prospective teachers develop the ability to guide multiple classes in line with the changing teacher training policy, and develop and provide high-quality online and offline programs for field teacher re-education.

The effects of UIC Cooperation Programs on Youth Employment (정부 산학연협력 지원의 고용효과 분석)

  • Kim, Sunwoo;Yoon, Yoon-Gyu
    • Korean small business review
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    • v.42 no.2
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    • pp.179-193
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    • 2020
  • In the rapid trend of social change, such as the 4th industrial revolution and the realignment of job structures, university-industry cooperation(UIC) is emphasized as a key factor in enhancing national competitiveness. The level of UIC in Korea is insufficient compared to national competitiveness, and despite the world-class R&D investment, there is a lack of linkage between the result of technology development and the industrial field, and the knowledge-transfer between university and industry is also insufficient. This paper analyzed the employment effects of UIC program supported by government, especially youth employment effects. The companies participating in the UIC program showed higher employment effect than the non-participating companies. In addition, the result of examining the employment growth rate of participating companies only for projects aimed at 'education and human resource development', show that employment growth rate after one year (total, youth employment) was significantly higher than that of non-participating companies, while employment growth after two years was not significant. UIC program need to have sustainability and systemicity so that they can be directly linked to the employment effects.

Changes in Early Childhood Pre-service Teachers' Perceptions of the Disabilities, Attitudes toward Inclusive Education, and Teacher Efficacy through Capstone Design-based Disability Teaching Materials Production Classes (캡스톤 디자인 기반 장애교재교구 제작을 통한 예비보육교사의 장애 인식, 통합교육에 대한 태도 및 교사효능감의 변화)

  • Park, Mi-Kyung
    • The Journal of the Korea Contents Association
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    • v.21 no.11
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    • pp.793-805
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    • 2021
  • The purpose of this study was to identify changes and differences in perceptions of disabilities, attitudes toward inclusive education, and teacher efficacy in Early childhood pre-service teachers through capstone design-based disability teaching material production classes. The study participants were 50 third-year child care majoring students (25 experimental group, 25 comparison group) who participated in capstone design class for one semester in 2020 at 3-year K university. Looking at the results of the study, the experimental group, which produced teaching materials for the disabilities, showed significant changes in disability awareness, attitude toward inclusive education, and teacher efficacy than the comparative group. there was a positive change in the perception of disability due to an increase in the overall understanding and knowledge of the disabilities. It is judged that these positive changes in the perception of people with disabilities gave positive changes to the attitude toward inclusive education and teachers' efficacy. This positive change of early childhood pre-service teachers will serve as an opportunity to improve the quality of teaching behavior and various roles of teachers when interacting with children with disabilities in the inclusive education field.

A Study on the Perception of Information Search Process(ISP) and the Verification of Effectiveness of Scaffolding Strategy (정보탐색과정(ISP)에 대한 인식조사 및 스캐폴딩 전략의 효과성 검증)

  • Jeong-Hoon, Lim;Byeong-Ki, Lee
    • Journal of the Korean Society for Library and Information Science
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    • v.56 no.4
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    • pp.239-267
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    • 2022
  • In this study, the adolescents' perception of the Information Search Process(ISP); their anxiety and the need for intervention during the process were investigated based on Kuhlthau's ISP model, and the relationship among the factors was analyzed with structural equations. In addition, the effectiveness of scaffolding strategy to the experimental group during the class was verified. The main findings are as follows. First, as a result of exploring the anxiety felt by learners and the need for intervention in the information search process, it was found that the presentation stage had a significant effect on the anxiety, and the collection, presentation, and assessment stages had significant effects on the need for intervention. Second, as a result of controlling each variable to investigate the anxiety felt by learners and necessity of intervention in the information search process, it was confirmed that among the demographic variables, the difference between the first graders and the second ones was significant; and the difference in the metropolitan area was more significant than that in the Gangwon province. Third, as a result of paired t-test and covariance analysis on the control group and the experimental group, it was confirmed that the anxiety and need for intervention of the experimental group were statistically significantly reduced. The significance of this study lies in the point that it presents a practical basis for applying scaffolding strategies appropriate to information search process in the field of education.

Design and Development of the SNIPE Bus System (초소형위성 SNIPE 본체 설계 및 개발)

  • Kim, Hae-Dong;Choi, Won-Sub;Kim, Min-Ki;Kim, Jin-Hyung;Kim, KiDuck;Kim, Ji-Seok;Cho, Dong-Hyun;Lee, Jaejin
    • Journal of Space Technology and Applications
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    • v.2 no.2
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    • pp.81-103
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    • 2022
  • In this paper, the contents of the design and development process of the 6U micro-satellite Snipe (SNIPE, national name Toyosat; small scale magnetospheric and Ionospheric plasma experiment ), which was developed to observe the near-global space environment through polarization flight for the first time in Korea, were described. Snipe performs transversal flight to observe the Earth's surrounding space environment in three dimensions, and aims to simultaneously observe the space plasma density and temperature in the ionosphere, as well as temporal changes in the solar magnetic field and electromagnetic waves. In this way, it was developed by dividing it into a test certification model (EQM) and a flight model (FM) to perform the actual mission for at least six months, away from developing a cube satellite for short-term space technology verification or manpower training. Currently, Snipe, which has completed the development of a total of four FM and completed all space environment tests, is scheduled to launch 2023. In this paper, we introduce the design contents and development process of the Snipe satellite body ahead of launch, and hope that it will be a useful reference for the development of 6U-class micro-satellite for full-scale mission in Korea.