• 한국수자원학회논문집
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• 제38권6호
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• pp.429-438
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• 2005

본 연구에서는 Boussinesq 방정식을 이용하여, 불규칙 파랑의 직접적인 해석이 가능한 한 쌍의 상미분방정식을 유도하였다. 입사파랑은 TMA(TEXEL storm, MARSEN, ARSLOE) 천해 스펙트럼을 이용하여 재현하였으며, 지배방정식은 4차 Runge-Kutta 법을 이용하여 적분하였다. 새로 유도된 파랑 방정식을 이용하여, 일정 수심을 진행하는 파랑의 비선형 에너지 교환효과를 계산하였다. 또한, 일정 경사면의 정현파형 지형을 통과하는 불규칙파랑의 특성에 관해 수치적으로 검토하였다. 비선형성이 불규칙파랑의 통과와 반사에 큰 영향을 주었다.

• Nuclear Engineering and Technology
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• 제55권5호
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• pp.1742-1756
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• 2023

The hydrogen behavior in a nuclear containment vessel is a significant issue when discussing the potential of hydrogen combustion during a severe accident. After the Fukushima-Daiichi accident in Japan, we have investigated in-depth the hydrogen transport mechanisms by utilizing experimental and numerical approaches. Computational fluid dynamics is a powerful tool for better understanding the transport behavior of gas mixtures, including hydrogen. This paper describes a Large-eddy simulation of gas mixing driven by a high-buoyancy flow. We focused on the interaction behavior of heat and mass transfers driven by the horizontal high-buoyant flow during density stratification. For validation, the experimental data of the Containment InteGral effects Measurement Apparatus (CIGMA) facility were used. With a high-power heater for the gas-injection line in the CIGMA facility, a high-temperature flow of approximately 390 ℃ was injected into the test vessel. By using the CIGMA facility, we can extend the experimental data to the high-temperature region. The phenomenological discussion in this paper helps understand the heat and mass transfer induced by the high-buoyancy flow in the containment vessel during a severe accident.

• 정보처리학회논문지A
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• 제18A권6호
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• pp.233-240
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• 2011

본 논문은 지속적으로 증가되고 있는 인터넷 역기능들을 미디어리터러시 기반의 소셜네트워크 서비스 스템을 통하여 미디어 접근능력, 비판적 이해능력, 창의적 표현능력, 참여와 소통능력을 향상 시켜 줄 수 있는 L-SNS시스템을 설계 및 구현 하였다. 구현된 L-SNS시스템은 학습자들의 원활한 소통의 매개체로 스마트폰을 사용하였으며, 실시간 상호작용과 상대방의 입장을 이해 할 수 있도록 간접적 체험을 경험 할 수 있게 하였다. 또한 다른 학습자들의 심도 있는 토론을 제3자의 입장에서 보는 과정을 통하여 객관적 판단을 할 수 있는 환경을 제공하고자 하였다.

• 한국레이저가공학회지
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• 제13권2호
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• pp.1-5
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• 2010

A high speed laser texturing method that relies on laser scanner conditions, to form pattern shapes with micro-narrow surface detail such as dotted line features is demonstrated and analyzed. For example, this method may be used to piston ring and gear part for automotive. Data on friction characteristics of two laser patterns employed for STD61 steel will be shown. Comparison of pattern depths obtained by repetition overlapping process with laser scanner to the results on friction coefficient will be provide. It will be shown that friction characteristic in dotted line patterns can significantly depend upon interaction with the lubrication and laser pattern conditions. Laser pattern processing into a shallow depth provides only slight improvement in friction, while work into a deep shape indicates a significant improvement.

• Ocean Systems Engineering
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• 제7권2호
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• pp.107-120
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• 2017

Spud-can is used for fixing jack-up rig on seabed. It needs to be inserted up to the required depth during the installation process to secure enough soil reaction and prevent overturning accidents. On the other hand, it should be extracted from seabed soils as fast as possible during the extraction process to minimize the corresponding operational cost. To achieve such goals, spud-can may be equipped with water-jetting system including monitoring and control. To develop such a smart spud-can, a reliable numerical simulation tool is essential and it has also to be validated against physical model tests. In this regard, authors developed a numerical simulation tool by using a commercial program ANSYS with extended Drucker-Prager (EDP) formula. Authors also conducted small-scale (1/100) physical model tests for verification and calibration purpose. By using the numerical model, a systematic parametric study is conducted both for sand and K(kaolin)-clay with varying important soil parameters and the best estimated soil properties of the physical test are deduced. Then, by using the selected soil properties, the numerical and experimental results for a sand/K-clay multi-layer case are cross-checked to show reasonably good agreement. The validated numerical model will be useful in the next-stage study which includes controllable water-jetting.

• 품질경영학회지
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• 제51권4호
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• pp.531-550
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• 2023

Purpose: The unique nature of life-and-death healthcare services sets them apart from other service industries. While many studies exist on the relationship between healthcare services and customer satisfaction, most of them focus on mildly ill patients, ignoring the differences between critically ill and non-seriously ill patients. This study discusses the actual quality of healthcare services for patients who are facing life-threatening illnesses and are on life support, as well as their right to protection and dignity. Methods: The survey conducted to 149 patients with the four major illnesses: cancer, heart disease, brain disease and rare and incurable disease, those who have experiences with senior general hospitals. Results: The basic statistics of this study are adequate to represent the four major critical illnesses, and the reliability and validity of this study's hypotheses, which were measured by multiple items, were analyzed, and the internal consistency was judged to be high. In addition, it was found that the convergent validity was good and the discriminant validity was also secured. When examining the goodness of fit of the hypotheses, the SRMR, which is the standardized root mean square of residuals that measures the difference between the covariance matrix of the data variables and the theoretical covariance matrix structure of the model, met the optimal criteria. Conclusion: The academic implications of this study are differentiated from other studies by moving away from evaluating the quality of healthcare services for mildly ill patients and focusing on the rights and dignity of patients with life-threatening illnesses in four senior general hospitals. In terms of academic implications, this study enriches the depth of related studies by demonstrating the right to protection and dignity as a factor of patient-centeredness based on physical environment quality, interaction quality, and outcome quality, which are presented as sub-factors of healthcare quality. We found that the three quality factors classified by Brady and Cronin (2001) are optimized for healthcare quality assessment and management, and that the results of patients' interaction quality assessment can be used to provide a comprehensive quality rating for hospitals. Health and human rights are inextricably linked, so assessing the degree to which rights and dignity are protected can be a superior and more comprehensive measurement tool than traditional health level measures for healthcare organizations. Practical implications: Improving the quality of the physical environment and the quality of outcomes is an important challenge for hospital managers who attract patients with life and death conditions, but given the scale and economics of time, money, and human inputs, improving the quality of interactions and defining them as performance indicators in hospital quality management is an efficient way to create maximum value in the short term.

• 유통과학연구
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• 제11권6호
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• pp.59-65
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• 2013

Purpose - Studies of mechanism as a competitive strategy, a relatively new field in the study of strategic management research, has recently drawn the attention of the business management scholars. The literature has so far proposed the subjective-based view, environment-based view, and the resource-based view in its analyses of firm management. Hence, it is highly likely for the firm management to be reasonably thought of as a combination of and interaction among the three key elements of subject, environment, and resources this is the mechanism-based view (MBV). It is reasonable to consider firm management to be the combination of and interaction among the three key elements of subject, environment, and resources. The overall dynamic process that integrates these three elements and creates functional harmony is identified as the mechanism, the principle of firm management. Much of the extant literatures on MBV has mainly focused on case studies, a qualitative approach prone to subjectivity of the researcher, although the intuition from the study may lead to meaningful insights into a firm-specific mechanism. This study's focus is also on case analysis, but it still attempts a quantitative approach in order to reach a scientific and systematic understanding of the MBV. Research design, data, and methodology - I used both a qualitative and quantitative approach to a single model, given the complexity of the innovation processes. I conducted in-depth interviews with POSCO employees-20 from general management, two from human resources, eight from information technology, five from finance and accounting, and five from production and logistics management. Once the innovative events were selected, the interview results were double-checked by the interviewees themselves to ensure the accuracy of the answers recorded. Based on the interview, I then conducted statistical validation using the survey results as well. Results - This study analyzes the building process of innovation and the effect of the mechanism pattern on innovation by examining the case of POSCO, which has survived over the past 21 years. I apply a new analytical tool to study mechanism innovation types, perform a new classification, and describe the interrelationships among the mechanism factors. This process allows me to see how the "Subject"factor interacts with the other factors. I found that, in the innovation process of the adoption stage, Subject had a mediating effect but that the mediating effect of resource and performance was smaller than the effect of Subject on performance alone. During the implementation stage, the mediating effect of Subject increased. Conclusion - Therefore, I have confirmed that the subject utilizes resources reasonably and efficiently. I have also advanced mechanism studies: whereas the field's research methods have been largely confined to single case studies, I have used both qualitative and quantitative methods to examine the relationships among mechanisms.

• 한국과학교육학회지
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• 제31권2호
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• pp.239-255
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• 2011

이 연구는 초등 과학영재수업에서 코티칭의 활용에 대한 사례 연구로, 코티칭 과학영재수업의 특징을 수업 계획, 수업 진행, 수업 반성 및 평가 단계로 나누어 분석했다. 이를 위해 두 명의 교사가 코티칭을 활용하여 진행한 12차시의 과학영재수업을 관찰하고, 수업동영상과 교사들이 작성한 일지 및 교사들과의 심층면담 전사본 등을 분석했다. 연구 결과, 코티칭 과학영재수업의 특징으로 수업 계획 단계에서는 과학영재교육 프로그램의 질 향상, 과학영재교육 프로그램 개발에 대한 심리적 부담감 감소, 공동 수업 준비로 인한 일부 효율성 감소가 나타났다. 수업 진행 단계에서 나타난 특징으로는 역할분담을 통한 원활한 수업 진행, 학생들의 탐구 기회 증가, 교사의 미흡한 설명과 간과한 내용의 보완, 교사와 학생 및 학생간의 상호작용 증가, 실험안전사고의 위험 감소, 수업 진행에 대한 책임감 감소가 있었다. 수업 반성 및 평가 단계에서 나타난 특징은 평가 관점의 다양화, 수업 전문성 향상을 위한 배움의 기회 증가, 자신의 수업 평가에 대한 두려움 증가로 분류할 수 있었다.

• 자원환경지질
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• 제22권1호
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• pp.1-16
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• 1989

양평-원주지역 광화대에는 원생대 편마암류 내에 NS 단층파쇄대를 충진한 수십개조의 평행한 함 금-은 열수 맥상 광상들이 부존한다. 구조운동에 수반되어 3회에 걸쳐 진행된 열수 광화작용의 시기는 $67.5{\pm}1.6m.y.$이다. 일렉트럼(55.0-60.0wt. % Au)-방연석-섬아연석의 광화정출 작용은, 최대 압력 50기압 하에서, 8.2-2.wt. % NaCl상당 염농도를 갖는 광화유체로부터 $260-180^{\circ}C$에 걸쳐서 비등작용과 함께 냉각작용에 의하여 진행되었다. 비등작용과 유화광물의 침전에 의한 광화유체내 $H_2S$의 감소는 유황동위원소의 re-equilibration을 야기하고 $H_2S$의 ${\delta}^{34}S$값을 광화초기 -1.4-2.7‰에서 후기 6.6-9.2‰로 증가시켰다. 광화작용이 진행됨에 따라 열수유체내의 산소, 수소 안정동위원소의 값은 점점 감소하여 천수의 값에 가까와지는데, 이는 천수의 유입이 점진적으로 중가하였음을 뜻하며, 쥬라기 심부 열수계보다 큰 water-rock interaction의 값을 갖는 백악기 천부 열수 광상들의 값과 일치한다.

• 정보교육학회논문지
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• 제19권3호
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• pp.311-322
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• 2015

본 연구는 교사가 개발한 콘텐츠의 설계 동향과 문제들을 분석하고, 개선방안을 모색하였다. 교육정보화연구 대회에서 최근 3년 동안 1등급을 받은 콘텐츠들을 분석하였다. 콘텐츠를 8가지 교수 학습 활동 유형과 6가지 지식 유형으로 나누어 살펴보았을 때, 대부분의 콘텐츠가 개인교수 유형과 개념 및 원리 학습 유형에 치중되어 있었다. 한편, 교육용 소프트웨어 품질인증 기준을 적용한 결과, 다수의 준거들에서 미흡하게 설계된 것으로 밝혀졌다. 이와 더불어서, 내용 분석 방법을 적용하여 설계의 특성을 심층적으로 분석한 결과, 평가, 피드백, 학습목표 등과 관련하여 다수의 문제들이 발견되었으며, 이 외에도 수준별 학습 지원, 학습자와 내용 간의 상호작용, 텍스트와 내레이션 제시, 학습자 정보 처리, 화면 설계, 학습자의 수준을 고려한 내용 선정 등에서 몇 가지 공통된 문제들이 발견되었다. 분석 결과로 발견된 문제들과 관련하여 평가 문항 선정 및 안내, 피드백 내용 및 종류, 학습목표 기술, 학습내용 선정, 상호작용, 텍스트 제시, 화면 설계 등에 대한 개선 방안들이 제안되었다.