• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.480-480
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• 2018

전 세계적으로 자연 친화, 하천생태계 보전, 친수하천 등을 조성하기 위한 대대적인 하천 정비사업이 활발히 진행 중에 있다. 최근 홍수로 인한 제방 붕괴에 대응하기 위한 제방의 안정화 및 개선을 위한 방법으로 기존의 시멘트와 같은 혼합물질을 사용하지 않고 환경 친화적이고 지속 가능한 대안에 대한 수요가 증가되고 있는 추세이며 현재 노후화 된 불안정 제방에 대한 보강대책을 수립해나가는 과정으로써 친환경 신소재를 활용하여 제방을 보호하는 연구가 수행되고 있다. 제방사면에 적용되는 신소재는 바이오폴리머를 활용한 재료로써 공동연구기관 카이스트에서 개발된 환경 친화적인 물질로 미생물에 의해 유도된 고인장 및 인체 무해성 등의 특성을 갖고 있으며 경제적 타당성인 측면에서 시멘트와 비교 분석 되어야 하고 실제 현장에서의 적용 가능성, 신뢰성 및 내구성 검토 등 성능을 보장하기 위한 지속적인 연구가 필요한 상황이다. 이에 본 안동하천실험센터에서는 중규모 제방을 직접 제작하여 수리모형실험을 통한 친환경 신소재 활용 제방의 안정성 및 성능 평가를 실시하였다. 수리실험 조건은 카이스트에서 제시된 레시피를 기반으로 먼저 분말형태의 바이이폴리머를 물과 희석하여 만들어진 바이오폴리머 용액을 흙과 혼합한 뒤 제방표면에 직접 미장작업을 수행하여 실험조건에 따라 일정한 두께(1cm, 3cm, 5cm)로 피복하였다. 이후 월류 붕괴 실험이 가능한 3 - 5일 정도의 양생기간을 거쳐 실험을 진행하였다. 실험결과는 다수의 고프로(GoPro) 및 비디오 카메라 등 다양한 영상장치를 이용하여 픽셀기반의 영상분석기법을 활용한 시간 흐름에 따른 제방 사면에서의 붕괴규모를 산정하여 신소재의 피복 두께에 따른 제체의 붕괴 거동 및 안정성을 평가하였으며, 또한 제방 파괴부에서의 흐름 상황 및 유속이 붕괴 발달에 미치는 영향을 분석하기 위하여 PIV 분석을 실시하였다. 이번 연구의 최종목표는 지속적인 예비실험을 수행하여 월류 및 침투, 파이핑 등 파괴 인자 별 신소재의 성능 개선 및 개발된 새로운 공법에 대한 효과 검토를 통한 최적안을 도출함으로써 향후 실규모 실험실증을 통한 신소재 시공 및 공법에 대한 현장적용 가능성 검증을 거쳐 최종적으로 신소재 제방 공법 설계 기술, 신소재 및 공법 표준안, 제방공법 안정성 평가 가이드라인 등을 제시하고자 하며, 이러한 실험데이터를 축적함으로써 실제 제방 붕괴 시 비상대처계획 수립에 필요한 기초자료로 활용이 가능할 것으로 사료된다.

• Journal of vocational education research
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• v.37 no.3
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• pp.47-63
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• 2018

The purpose of this study is to develop the competency model of specialized vocational school teachers as admission officers. Whereas professional admission officers deal with a variety of admission activities in universities, teachers are responsible for admission duties in specialized high schools in Korea. Therefore, it is necessary to identify the core competencies required for teachers responsible for admission duties in specialized high school settings. In order to develop a competency model, factor analysis was completed for the survey results of 191 teachers who teach in specialized vocational high schools in Seoul, Korea. For evaluating validity of the competency model, the responses from those who had high experiences in admission duties and the average teachers were compared. As a result, this study identified a total of 14 competencies in three competency areas. The competencies required for specialized high school teachers include responsibilities for admission officers, ethics for evaluators, communication skills, teamwork, understandings of admissions process for specialized vocational high school, developing evaluation criteria, generating interview questions, increasing interrater reliability, interview skills, simultaneous evaluation of interviewees, quantification of evaluation results, synthesis of evaluation results, and decision making skills.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.721-729
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• 2018

As is the case with South Korea, if the authority for decision making on curricula is concentrated on the state level, the perspective of the understanding on the curricula could be said to be essential. And, such an understanding on the curricula can be important not only to the theorist of curricula but also the teachers in educational institutions. Also, there have been a number of studies to examine the awareness of the teachers on education reform. However, the studies on the resistance factor was mainly focused on the relationships with traits of individuals, covering factors such as their habits, maturity, character, and age, etc. But, it was difficult to find consistency in the results of these studies. Therefore, in this study, the researcher selected the teachers as the key factor of the execution of the curricula and examined the awareness of the teachers on education resistance and the negative views thereupon in the relationship between the knowledge, attitude, skills, and education execution, with a view to find another meaning. The subjects of this study were selected among the teachers in middle or high schools located in Gangnam, Songpa, and Joonggu districts of Seoul. The survey was conducted online with 15 institutions over three weeks from April 13 to 30, 2018. The data gathered were analyzed using SPSS 20.0 and AMOS 20.0, in order to validate the hypotheses through frequency analysis, confidence analysis, factor analysis, structural equation model, and sobel-test. The result of the analyses showed that the factors that affected execution of curricula were the skill system, knowledge system, and attitude of the teachers, in that order, with a positively significant influence. And, significant differences were identified between the factors depending on high or low resistance among teachers.

• The Journal of Internal Korean Medicine
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• v.40 no.3
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• pp.390-408
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• 2019

Objectives: Several pattern diagnosis questionnaires have been developed to objectify the process of pattern diagnosis in Korean medicine. In this context, this study aimed to develop a food retention questionnaire for functional dyspepsia (FRQ-FD) by modifying the previously developed food retention questionnaire (FRQ) and to verify its reliability and validity. Furthermore, this study aimed to identify the optimal cut-off value of the FRQ-FD for standardization and use in clinical situations. Methods: To develop the FRQ-FD, we extracted the major symptoms of food retention pattern for functional dyspepsia from Chinese/Korean medicine textbooks and requested an importance survey from experts using the Delphi method. The first draft of the FRQ-FD was composed of 25 questions comprising 8 questions from the textbooks and the Delphi method and 17 questions from the FRQ already developed in 2013. To analyze its reliability, validity, and optimal cut-off value, 60 subjects were enrolled in this study from June 25 to August 13, 2018. Thirty patients were diagnosed as both functional dyspepsia and food retention pattern, and 30 healthy participants were not. All participants were requested to fill up the FRQ-FD, Stomach Qi Deficiency Questionnaire (SQDQ), Scale for Stomach Qi Deficiency pattern (SSQD), visual analog scale (VAS) for dyspepsia, Nepean Dyspepsia Index-Korean version (NDI-K), and functional dyspepsia-related quality of life (FD-QoL). Results: No statistically significant differences were found in sex distribution, age, and body mass index between the patient group and the control group. As five questions affected the reliability negatively and three questions affected the clinical validity negatively, we decided to exclude the eight questions upon further investigation. The Cronbach's ${\alpha}$ coefficient of the revised FRQ-FD (17 items) was 0.899, and its clinical validity was verified. Construct validity was analyzed by factor analysis and produced five factors. Statistically significant positive correlations were found between the revised FRQ-FD and the other dyspepsia scales, namely, SQDQ, SSQD, VAS, NDI-K, and FD-QoL. VAS and NDI-K especially had strong positive correlations with FRQ-FD. Conclusions: The FRQ-FD developed in this study can provide fundamental reliability and validity for a pattern diagnosis questionnaire. FRQ-FD can help to diagnose food retention pattern in functional dyspepsia patients. Further studies are required to inspect several statistical factors.

• Journal of the Korea Society for Simulation
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• v.28 no.2
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• pp.35-48
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• 2019

Domestic hydraulic drifters till now have been developed by benchmarking products from overseas leading companies. However, they do not have excellent impact performance as they are not suitable for characteristics (large flow rate and low pressure) of Korean hydraulic drill power pack, and therefore, research on the optimum design has not made much headway. This study performs multi-objective function optimization for hydraulic drifters whose capacity has been redesigned to deal with the large flow rate, and also with the help of this function, it aims to improve impact power and reduce supply and surge pressure. A summary of the research study is as follows: First, we set goals for improving impact power, supply pressure, and surge pressure, and then perform multi-objective function optimization on them. After that, we secure the reliability of the optimized analytical model by comparing the test results of the prototype built by the optimized design with the analysis results of the analytical model. This study used SimulationX, that is the hydraulic system analysis software, and EasyDesign, which is a multi-objective function optimization program. Through this research, we have achieved the results that satisfy the goal of developing high power drifters suitable for Korean type hydraulic drills.

• Informatization Policy
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• v.26 no.3
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• pp.3-35
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• 2019

In the fourth industrial revolution age, because of advance in the intelligence information technologies, the various roles of AI have attracted public attention. Starting with Google's Alphago, AI is now no longer a fantasized technology but a real one that can bring ripple effect in entire society. Already, AI has performed well in the medical service, legal service, and the private sector's business decision making. This study conducted an exploratory analysis on the possibilities and issues of AI-driven policy decision making in the public sector. The three research purposes are i) could AI make a policy decision in public sector?; ii) how different is AI-driven policy decision making compared to the existing methods of decision making?; and iii) what issues would be revealed by AI's policy decision making? AI-driven policy decision making is differentiated from the traditional ways of decision making in that the former is represented by rationality based on sufficient amount of information and alternatives, increased transparency and trust, more objective views for policy issues, and faster decision making process. However, there are several controversial issues regarding superiority of AI, ethics, accountability, changes in democracy, substitution of human labor in the public sector, and data usage problems for AI. Since the adoption of AI for policy decision making will be soon realized, it is necessary to take an integrative approach, considering both the positive and adverse effects, to minimize social impact.

• Journal of Sasang Constitutional Medicine
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• v.31 no.2
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• pp.12-21
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• 2019

Objectives This study was aimed to evaluate the one-year test-retest reliability of the Korea Sasang constitutional diagnostic questionnaire (KS-15) in university students. Methods In March 2017, and March 2018, a survey was sent by email to 583 Korean medicine students in two universities. Of these, 149 (25.6%) participated and completed the first survey (test) and second survey (retest). Participants responded to the KS-15 questionnaire and the general characteristics including their age, sex, height, and weight. Cohen's kappa Spearman's rank correlation coefficient and agreement rate (%) were used for the test-retest reliability for each question item and the diagnosis of the Sasang constitution. The independent T-test was used to determine the difference in BMI between Sasang constitutional accordance and discordance groups obtained from the test-retest results of KS-15. Results The agreement of Sasang constitutional diagnosis was 75.8% (Kappa = 0.618), indicating that KS-15 had a certain level (substantial) of test-retest reliability. However, the kappa of each item was 0.161 ~ 0.620, which showed a large difference between the items. The agreements of each Sasang constitution were 85.1% for Taeeumin, 73.6% for Soeumin, and 58.6% for Soyangin. There was no significant difference in the BMI change between Sasang constitutional accordance and discordance groups in the test-retest. Conclusions These results indicate KS-15 has a reliable one-year test-retest reliability. However, further studies will be required to improve reliability, validity and application across different age ranges for the practical utilization of KS-15.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.1
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• pp.42-54
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• 2019

Crop models depend on a large number of input parameters including the cultivar parameters that represent the genetic characteristics of a given cultivar. The cultivar parameters have been estimated using high quality data for crop growth, which require considerable costs and efforts. The objective of this study was to examine the feasibility of using low quality data for the parameter estimation. In the present study, the cultivar parameters for cv. Shindongjin were estimated using the data obtained from the report of new cultivars development and research from 2005 to 2016. The root mean square errors (RMSE) of the heading dates were less than 3 days when the parameters associated with phenology were estimated. In contrast, the coefficient of determination for yield tended to be less than 0.1. The large errors incurred by the fact that no growth data collected over a season was used for parameter estimation. This suggests that detailed observation data needs to be prepared for parameter calibration, which would be aided by remote sensing approaches. The occurrence of natural disasters during a growing season has to be considered because crop models cannot take into account the effects of those events. Still, our results provide a reasonable range for the parameters, which could be used to set the boundary of a given parameter for cultivars similar to cv. Shindongjin in further studies.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.2
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• pp.123-131
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• 2021

The buffer is a key component of an engineered barrier system that safeguards the disposal of high-level radioactive waste. Buffers are located between disposal canisters and host rock, and they can restrain the release of radionuclides and protect canisters from the inflow of ground water. Since considerable heat is released from a disposal canister to the surrounding buffer, the thermal conductivity of the buffer is a very important parameter in the entire disposal safety. For this reason, a lot of research has been conducted on thermal conductivity prediction models that consider various factors. In this study, the thermal conductivity of a buffer is estimated using the machine learning methods of: linear regression, decision tree, support vector machine (SVM), ensemble, Gaussian process regression (GPR), neural network, deep belief network, and genetic programming. In the results, the machine learning methods such as ensemble, genetic programming, SVM with cubic parameter, and GPR showed better performance compared with the regression model, with the ensemble with XGBoost and Gaussian process regression models showing best performance.

• Tunnel and Underground Space
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• v.31 no.4
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• pp.243-269
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• 2021

Since the early 2010s, the social importance of research and practical projects targeting deep geological disposal of high-level nuclear waste, underground CO₂ storage and characterization of deep subsurface by borehole investigation has been increasing. In this regard, there is also a significant increase in the need for in situ test technology to obtain quantitative and reliable information on the hydraulic characteristics of deep rock mass. Through years of research and development, we have independently set up Deep borehole Hydraulic Test System (DHTS) based on the key apparatuses designed and made with our own technology. Using this system, high precision constant pressure injection tests were successfully completed at the two 1 km boreholes located in Mesozoic granite and sedimentary rock regions, Gyeongju. During the field tests, it was possible to measure very low flow rate below 0.01 l/min with micro flow rate injection/control module. In this paper, the major characteristics of DHTS are introduced and also some results obtained from the high precision field tests under the deep and low permeable rock mass environment are briefly discussed.