• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.719-724
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• 2016

This paper describes the performance improvement of an inrush current limiter to prevent damage or malfunctions in power converters due to the inrush current. When the power converter of military radar is operated, the circuit breaker of the power converter is often activated because the overcurrent flows through the circuit breaker of the power converter. Therefore, this study performed a cause analysis of the problem, which is a larger current flow than the intended current(250A). The operation principle of an inrush current limiter and SCR (Silicon Controlled Rectifier) used in the inrush current limiter was analyzed. As a result, the overcurrent flow through the circuit breaker was found to be due to dv/dt triggering of SCR. Based on cause analysis, this paper proposes a technique by adding the resistor in front of the SCR to prevent an unnecessary inrush current. Finally, the effectiveness of the improvement was verified by measuring the output current in the inrush current limiter. The power converter equipped with the improved inrush current limiter operated for more than 1 year without the circuit breaker of the power converter being activated.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.6
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• pp.722-728
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• 2012

Urban sewer systems has a limitation of capacity of rainwater storage and problem of occurrence of untreated sewage, so adopting a storage facility for sewer flooding prevention and urban non-point pollution reduction has a big attention. The Korea Ministry of Environment has recently introduced a new concept of "multi-functional storage facility", which is crucial not only in preventive stormwater management but also in dealing with combined sewer overflow and sanitary sewer discharge, and also has been promoting its adoption. However, reserving a space for a single large-scale storage facility might be difficult especially in urban areas. Thus, decentralized construction of small- and midium-sized storage facilities and its operation have been introduced as an alternative way. In this paper, we propose a model predictive control scheme for an optimized operation of distributed storage facilities and sewer networks. To this aim, we first describe the mathematical model of each component of networks system which enables us to analyze its detailed dynamic behavior. Second, overflow locations and volumes will be predicted based on the developed network model with data on the external inflow occurred at specific locations of the network. MPC scheme based on the introduced particle swarm optimization technique then produces the optimized the gate setting for sewer network flow control, which minimizes sewer flooding and maximizes the potential storage capacity. Finally, the operational efficacy of the proposed control scheme is demonstrated by simulation study with virtual rainstorm event.

• Journal of Oriental Neuropsychiatry
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• v.32 no.3
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• pp.167-184
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• 2021

Objectives: Operational definition and its validated measure of traditional Korean medicine (TKM) are pivotal for research studies and reliable clinics. There have been ten years of clinical studies on Eum-Yang (Yin-Yang) and Sasang typology using Sasang Personality Questionnaire (SPQ) of integrative biopsychology. The objective of this study was to perform a systematic review on the use of SPQ to provide insights and foundation for its further studies and clinical application. Methods: Clinical studies on SPQ were searched using five domestic and foreign research databases. Attained research articles were then subjected to predefined systematic reviews. Demographic characteristics of participants and research topics of articles were described. Psychological and physical features of SPQ and its subscales were reviewed and compiled to reveal biopsychological characteristics. Results: There were 33 articles with 15,085 participants on Eum-Yang (n=19) and Sasang typology (n=14). The SPQ-total score was in an increasing order of So-Eum, Tae-Eum, and So-Yang. Eum-Yang groups were categorized at a 3:4:3 ratio using %ile score of SPQ-total. The SPQ-total showed a significant positive correlation with Novelty-Seeking and a negative correlation with Harm-Avoidance in psychological perspective, while it was not significantly correlated with Body Mass Index or Ponderal Index in physical perspective. The SPQ-total and subscales explained psychopathological characteristics of stress recognition, negative emotion, problem behavior, and depression. Conclusions: The SPQ was found to be an objective biopsychological measure of TKM for Sasang typology and psychopathology. It would provide foundation for 'Korean Psychology' and multidisciplinary studies.

• Journal of The Korean Association For Science Education
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• v.38 no.6
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• pp.793-812
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• 2018

This study, from a critical view on knowledge-centered science education, aims to explore the wisdom that can be acquired from science. In other words, to find the categories and examples of "Wisdom of Science(WOS)" that can be shared in science classroom is the purpose of this study. For the data collection, twelve hours of physics classes of three high schools were observed, together with teacher interviews and student interviews. Collected data were analyzed qualitatively based on the operational definition of WOS. In this study, WOS was defined in a limited sense to mean 'wise action such as behaviors, attitudes, methods, and thoughts that can be found in the process of formation and application of scientific knowledge'. The results of this study, i.e. three categories and six examples of WOS, can be summarized as follows. First category of WOS is 'wisdom as a scientific attitude'. The examples of this category are 'rational suspicion and open-minded attitude', and 'effort to find the best way in given situation'. Second category of WOS is 'wisdom as a method for problem solving'. The examples of this category are 'thinking with changing the conditions', and 'communication using the language of science'. Third category of WOS is 'wisdom as a reflection about science and human'. The examples of this category are 'understanding of the relationship between science and society', and 'perceiving the relationship between science and my life'. In conclusion, "Wisdom-oriented Science Education" as an alternative goal of future science education is suggested with its meanings and implications.

• 재활복지
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• v.18 no.4
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• pp.165-186
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• 2014

The purpose of the study is intended to analysis on students adjustment of students with disabilities in a special class of the elementary school focused on KCI journals through a systematic review. This study was searched from papers published from Jan, 2004 to May, 2014 using KISS, DBPIA, RISS, Google databases. The key words were "inclusive education, special class, inclusive class, student with disabilities, school adjustment, school life, school adjustment scale, elementary school". Results of data analysis were follows; 1. A total of 35 papers were analyzed. Except for 6 papers published in 2004~2007, 29 papers were published after 2008.; 2. The participant of study subject was total 141. Students with intellectual disability were 61.7%. Students with learning disabilities were 17.0%.; 3. The assessment domain of study was analyzed total 51 data.; academic achievement and task performance (25.4%), class attitude and participatory behavior(23.5%), problem behavior(21.5%). The Study in student with intellectual disability was 10 assessment domains.; 4. The method of assessment was total 41.; the use of operational definition(56.1%), the development of test (17.1%), and the use of assessment tool(14.6%).

• The Korean Journal of Archival Studies
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• no.60
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• pp.49-88
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• 2019

Today, the civil society plays a key role not only in criticizing and monitoring the functions of the state and the market, but also as an active producer of public services by complementing the government and the public sector. Public records management is also becoming more and more popular. In the case of appraisal and selection, which is the core area of record management, discussions about citizen participation are becoming more serious than any other areas. The concept of 'proactive appraisal', which has emerged as a paradigm of citizens' participation in appraisal, reminds us that citizens themselves are the subjects of public records and are no longer alienated from the appraisal system. The problem is, while the growth of the Korean civil society about institutional participation is spreading rapidly, but citizen participation is hard to find in the field of public records. The purpose of this paper is to examine the role of citizen participation in the process of appraisal of public records, and to debunk the role of citizen participation in the appraisal processes by exploring the examples in the UK, Canada, and Australia. This paper emphasizes that the appraisal system of the national public records in crisis today could be largely restored through the domestic application of this active citizen participation cases. First of all, this study presents a conceptual appraisal model that could reflect citizen participation in the field of record management along with the analyses of the advanced cases in some western countries. Specifically, this paper focuses on presenting the models of 'appraisal documentation' and 'governance-based appraisal', reflecting the active citizen participation. This study suggests that these citizens' participatory evaluation models should be settled in Korea in the future and we should urgently discuss 'citizen participation appraisal'.

• Journal of Korean Society on Water Environment
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• v.36 no.6
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• pp.546-558
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• 2020

While industrialization has provided in abundance, the pollution it creates has caused untold damage to the environment, increasing the frequency and severity of natural disasters through changes in global climate patterns. The World Risk Forum's (WEF) World Risk Report presented the results of a survey of experts from around the world detailing the most influential risk factors over the next decade. Notably, the failure to respond to climate change ranked first and the global water crisis third. The extreme drought in the western Chungnam province was unexpected in 2016. At the time, the water level of Boryeong Dam was drastically decreased due to receiving less than half the average recorded rainfall in the region that year. The Boryeong Dam diversion pipeline has the capacity to solve the water shortage problem between these two regions by providing water from Geumgang to the western part of Chungnam, including Boryeong City. Current weather trends suggest drought is likely to continue in western Chungnam, which uses the Boryeong Dam as an intake source. This makes it necessary to operate Boryeong Dam diversion pipeline in an efficient and effective manner. SWAT is a watershed scale model developed to predict the impact of land management practices on water. The SWAT model was used in this study to evaluate the adequacy of the Boryeong Dam diversion pipeline operational plan by comparing it to present Boryeong Dam diversion pipeline operation. By investigating the number of days required to reach each reservoir stage, we determined that the number of days required to reach the boundary stage was less than that of the current operation. This determination accounts for the caveats that the Boryeong Dam waterway was not operated and only one pump will be operated from October to May of next year. As our results suggest, the most stable operation scenario is to operate two pumps at all times. This can be accomplished by operating two pumps from the caution stage to increase the number of pumps whenever the stage is raised. In addition to the stable operation of the Boryeong Dam pipeline, policy considerations are required with regard to imposing a water use charge on users of the Boryeong Dam region.

• The Journal of the Korea Contents Association
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• v.21 no.8
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• pp.236-246
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• 2021

The purpose of this study was to help solve the problems of the high school credit system by exploring its operation plans for both career guidance and the effective and efficient operation of the high school credit system. The study's research method was literature research; it examined prior research, public hearings, press releases, the 2015 revised curriculum, and plans to promote the high school credit system by the Ministry of Education. To solve the problems facing the high school credit system, the curriculum should be organized as follows. First, it should be organized around general subjects. Second, students need to be able to study subjects related to their desired fields in depth. Third, it is necessary to confirm the basis for organizing the curriculum. Meanwhile, the following steps should be taken to improve the operation of the high school credit system for career guidance. First, a career curriculum committee for career learning and coaching should be formed and operationalized. Second, the teachers' work system should be restructured. Third, career aspirations should be identified, and directions for further study should be researched. Fourth, career and academic design guidance coaching books should be provided. Fifth, it is the role of the career and academic design guidance teacher. Sixth, emphasis should be placed on responsibility for subject selection and preparation for re-taking program.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.6
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• pp.409-415
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• 2021

Medical waste management is becoming increasingly important, specifically in light of the current COVID-19 pandemic, as hospitals, clinics, quarantine centers, and medical research institutes are generating tons of medical waste every day. Previously, a traditional incineration process was utilized for managing medical waste, but the lack of landfill sites, and accompanying environmental concerns endanger public health. Consequently, an innovative sterilization shredding system was developed to resolve this problem. In this research, we focused on the design and numerical analysis of a shredding system for hazardous and infectious medical waste, to establish its operational performance. The shredding machine's components were modeled in a CAD application, and finite element analysis (FEA) was conducted using ABAQUS software. Static, fatigue, and dynamic loading conditions were used to analyze the structural stability of the cutting blade. The blade geometry proved to be effective based on the cutting force applied to shred medical waste. The dynamic stability of the structure was verified using modal analysis. Furthermore, an S-N curve was generated using a high cycle fatigue study, to predict the expected life of the cutting blade. Resultantly, an appropriate shredder system was devised to link with a sterilization unit, which could be beneficial in reducing the volume of medical waste and disposal time, thereof, thus eliminating environmental issues, and potential health hazards.

• Journal of Practical Engineering Education
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• v.13 no.3
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• pp.515-532
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• 2021

The purpose of this study was to analysis of PBL for Korean Apprenticeship Program in Mechanical Engineering. The details of the study were as follows: First, the perception related to the PBL of Korean apprenticeship program was investigated. Second, the utilization and the operational difficulties of PBL for Korean Apprenticeship Program were investigated. Third, the supporting system for PBL was suggested. Research methods were literature research, questionnaire survey and FGI. The survey was conducted online from July 15 to August 14, 2021. A total of 515 respondents responded. A total of 108 in 515 respondents were in Mechanical Engineering. FGI conducted a total of 25 people who actual use PBL in the field of Korean Apprenticeship Program. Conclusions and suggestions based upon the result of this study are as follows. First, It is necessary to improve the utilization of PBL for Korean Apprenticeship Program in Industry. Second, PBL is necessary to apply optionally according to the job and field situation. Third, it is necessary to support system of evaluation for PBL in Korean Apprenticeship Program. Finally, related operation model and guideline need to be prepared for best practice.