• Transactions on Electrical and Electronic Materials
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• 제16권1호
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• pp.20-24
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• 2015

We studied the relationship between the surface smoothness of the internal Cu ribbon and the morphology of the Sn-Pb plating layer for solar cell modules. A bumpy surface was observed on the surface of the solar ribbon, which caused irregular reflection of light. Large, Pb-rich, primary ${\alpha}$-phases were found below the convex surface of the solar ribbon, passing from the surface of the internal Cu ribbon to the surface of the plating layer. The primary ${\alpha}$-phases heterogeneously nucleated on the convex surface of the Cu ribbon, and then largely grew to the convex surface of the plating layer. The restriction of the primary ${\alpha}$-phase's formation was enabled by enhancing the smoothness of the Cu ribbon's surface; it was also possible to increase the adhesive strength and decrease contact resistance. We confirmed that the solar ribbon's surface smoothness depends on the internal Cu ribbon's surface smoothness.

• 한국해양공학회지
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• 제28권1호
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• pp.55-63
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• 2014

In this paper, we propose an threshold-based Schur algorithm for estimating the media characteristics of sub-bottom multi-layers by using the signal generated by a parametric array transducer. We use the KZK model to generate a parametric array signal, and use the proposed threshold-based Schur algorithm for estimating the reflection coefficients of multiple sea bottom layers. Using computer simulation, we verify that the difference frequency component generated by the KZK model prevails over the signals of primary frequencies at long range. For the simulation, we use the transmit signal generated by the KZK and the reflected signal obtained from a lattice filter model for the seawater and sub-bottom of multi-level non-homogeneous layers. Through the simulation, we verify that the proposed threshold-based Schur algorithm can give much more accurate and efficient estimates of the reflection coefficients than methods using received signal, matched filter output signal, and normal Schur algorithm output.

• 한국직업건강간호학회지
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• 제12권2호
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• pp.134-145
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• 2003

Purpose: The present study examines symptoms of VDT syndrome perceived by those nurses reviewing the application of health insurance at hospitals. This study also investigates those factor influencing on the experience of VDT syndrome among those nurses. Method: Data were collected through mail questionnaire survey in April, 2003. Of the 250 questionnaires disseminated, 214 questionnaires were finally analyzed using descriptive statistics and multiple regression analysis through SPSS/PC version 10.0. Result: Of the VDT syndrome, the musculoskeletal symptom score was highest, followed by ophthalmologic symptoms. The musculoskeletal symptoms were higher among younger nurses, having smaller space under the desk, and feeling uncomfortableness of the chair. The ophthalmologic symptoms were higher among those with a bachelor's degree, younger nurses, and those having a light reflection on the computer monitor, and those maintaining less than 40cm between eyes and the monitor. Higher dermatologic symptoms were observed among younger nurses and those using unclear monitor. The psychological symptoms were higher among younger nurses, those having a light reflection on the monitor, those unable to control the height of their chair, and those using uncomfortable chair. The overall symptoms were higher among younger nurses, those having a light reflection on the monitor, and those smaller space under the desk. Conclusion: Primary intervention should be given to those nurses with symptoms of VDT syndrome in order to regain health and prevent further aggravation of the symptoms. In particular, self-care behaviors of the nurses using VDT should be promoted with administrative support.

• 한국환경과학회지
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• 제32권11호
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• pp.801-809
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• 2023

The purpose of this study is to predict the reflection distance following to the pulsing pressure, total air supplying, filter bag size using numercial analysis techniques and use it as an efficient operation condition and economic data for off-line type pulse air jet bag filter. In this research, filtration area 6 m² condition, calculate filter resistance coefficient for simulation through the main experiments using coke dust. Ansys fluent V19.0 apply to CFD simulation, and analysis pulsing characteristics about pulsing pressure, filtration velocity and nozzle diameter. The maximum reflecting distance of off-line type pulse air jet bag filter is 1,000 mm regardless of total air supplying at over the 42 L/m² conditions, that indicates off-line type can extend filter bag length 1,000 mm than on-line type. In order to effective primary and secondary pulsing of off-line type pulse air jet bag filter, over the 5 bar of pulsing pressure and over the 42 L/m² of total air supplying are needed.

• 한국철도학회논문집
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• 제17권1호
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• pp.7-13
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• 2014

팬터그래프와 전차선 사이의 이선을 유발하는 주요 요인은 팬터그래프로 인하여 전차선에 야기되는 파동의 전파와 반사 그리고 열차 진행방향의 전차선로 강성변화이다. 본 논문의 목적은 200km/h급 일반철도와 300km/h급 고속철도에서 이선을 효과적으로 줄이기 위하여 앞서 언급하였던 두 가지 요인 중에서 어느 쪽을 중요하게 고려해야 하는지를 분석하는 것이다. 고속철도 경우에는 파동의 전파와 반사가 강성 변화에 비하여 집전성능에 영향을 더 크게 미친다. 증속을 위해서는 드로퍼 경량화와 전차선 고 장력 부여를 위한 고 강도 전차선 개발이 필요하다. 파동전파속도를 향상하기 위하여 조가선의 장력을 증가시키면 오히려 집전성능을 악화할 수 있음에 유의해야 한다. 200km/h급 일반철도의 경우에는 전차선로 강성 변화가 파동 전파 및 반사에 비하여 집전성능에 영향을 더 미치므로 강성변화를 완화시키기 위하여 경간길이 축소, 전차선로의 장력 증가 및 드로퍼배치 최적화가 필요하다.

• Journal of Astronomy and Space Sciences
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• 제1권1호
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• pp.55-65
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• 1984

A total of 618 photoelectric observations (302 in yellow and 316 in bule) is made in 1982 at the Yonsei University Observatory. Except that of the secondary eclipse the homogeneous coverage of observations successfully secured B, V, and B-V light curves. Enhanced distortions in the light curves are appeared at the phases aroung $0.^P1$, which supports the wave-like migration period of 9.7 years(Rodono 1981). One epoch time of the primary minimum was made by combining the observations in three nights. This minimum time shows that the O-C values are still decreasing and there seems to indication of increasing. B and V light curves of the primary minimum are in strong asymmetry which show less luminous in the third and fourth contacts compared to those of the first and second ones. This asymmetry may be as a result of the reflection of the wave minimum at $0.^P1$, and B-V curve also shows asymmetry, redder at the third contact than the second one by about $0.^m04$. This color difference apperature distribution on the surface of cooler, larger component(KO IV star).

• 한국해양학회지
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• 제20권3호
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• pp.37-54
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• 1985

1984년 5월과 10월, 2회에 걸쳐 동해 서남 해역에서 조사한 수온, 클로로필-a, 영양염, 식물플랑크톤 및 일차생산에 관한 자료를 토대로 하여 대산 수역의 phytohydrography를 논의하였다. 식물플랑크톤의 종별 양적분포로 부터 특성 해수의 이전 환경을 추측할 수 있었는데, 이는 해양물리${\cdot}$화학적인 자료만으로는 기대하기 어려운 결과였다. 울기 및 감포 부근 해역의 상층부에서는, 그 하층에 근접한 냉수로 부터 영양염을 공급받아, 높은 일차생산력, 높은 클로로필-a 및 낮은 미세플랑크톤 비율 등의 특징이 나타났다. 반면에 대마난류수에는 매우 낮은 일차생산력, 빈약한 현존량 및 극히 높은 미세플랑크톤 비율 등의 특징이 나타나 좋은 대조를 이루었다. 연구해역에서 식물플랑크톤의 세포수 뿐만 아니라 클로로필-a 및 일차생산량에서도 미세플랑크톤이 압도적으로 우세함을 확인하였다. 이는 한반도 전해역 가운데 난류수가 예외적으로 강하게 유입되는 연구해역의 생물해양학적 특성을 잘 반영해 주는 현상이다.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제18권3호
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• pp.203-216
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• 2015

본 연구는 초등학교 6학년 수학 영재 학생을 대상으로 ACODESA 방법을 적용한 문제해결 과정에서 나타나는 표상 사용의 유형을 분석하였다. 수업 설계는 다양한 표상의 조직화된 사용을 강화시키는 ACODESA 방법에 따라 이루어졌으며 40분 동안 4차시에 걸쳐 수업이 진행되었다. 자료 분석을 위해 동영상 촬영, 학생과의 인터뷰 등을 수집하여 녹취록을 작성하였고, Despina(2011)의 표상 사용유형에 따라 표상의 변화를 분석한 결과 추가형, 정교화, 그리고 제한형이 나타났다. 이러한 연구 결과를 통해 문제해결 과정에서는 개인적 표상이 소그룹별 토론과 확인의 과정을 거쳐 제도적 표상으로 생성될 수 있는 수업 설계가 필요함을 알 수 있었다.

• 한국간호교육학회지
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• 제25권3호
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• pp.300-311
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• 2019

Purpose: The purpose of this study was to review and synthesize the existing literature on the experience of nursing students in simulation. Methods: A systematic review was undertaken using meta-ethnography. Eight databases were searched up to January 2014 for peer-reviewed studies, written in Korean and English, that reported primary data, used identifiable and interpretative qualitative methods, and offered a valuable contribution to the synthesis. Results: Nine studies were identified, with quality appraisal undertaken. Three key concepts were generated: ambivalence of simulation practice, learning by reflection, and building up of the competency as a future nurse. Six sub-concepts emerged: double sidedness of simulation setting; feeling ambivalence of simulation; learning from others; learning from self-reflection; improvement of confidence by role experience; and internalization of nursing knowledge. A line of argument has been developed based on the themes generated. Conclusion: The findings from this qualitative synthesis and other related literature indicated the importance of capability of educator and extension of the simulation system to facilitate effective simulation-based education.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제21권3호
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• pp.309-327
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• 2018

이 연구는 소수 나눗셈 수업을 중심으로 초등교사의 수업 성찰과 실행에 관한 사례 연구이다. 초등교사가 수학수업을 계획하고 실행하고 동료교사들과 자신의 수업을 비평하는 과정에서 어떤 고민을 하고 있으며 그 초점은 어떻게 변화해 가는지를 밝히고자 하였다. 수업을 계획하는 교사, 수업을 실행하는 교사, 동료교사와 자신의 수업을 비평하는 교사로 구분하고, 수학 목표, 과제의 실행, 수학적 표현, 수학적 담론, 질문의 설정, 개념적 이해와 절차적 능숙함, 생산적인 어려움, 학생 사고의 증거 활용 등의 8가지 측면을 따라 각 시기의 초등교사의 성찰과 실천을 분석하였다.