• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.49-50
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• 2002

Rapid advancements in analytical instrumentations and techniques in the last several decades offer an unprecedented opportunity to analyze the complex chemistry and probe the surfaces for chemical evidence. Recent developments in nanotechnology provide further ability to examine phenomena and mechanisms at the nanometer level. As a result of these advances, our understanding of the complex lubrication system has improved significantly. This paper will attempt to provide a molecular basis of how lubricant and additives function in lubrication.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.329-334
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• 2001

In this paper, the crack properties of steel fiber reinforced concrete (SFRC) structures for environment by experimental and analytical methods are discussed. The major role played by the steel fiber occurs in the post-cracking zone, in which the fibers bridge across the cracked matrix. Because of its improved ability to break crack, SFRC has better crack properties than that of reinforced concrete (RC). Crack properties are influenced by longitudinal reinforcement ratio, volume and type of steel fiber, strength of concrete.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(1)
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• pp.289-292
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• 2001

This paper investigates a RBF equalizer (RBFE) reducing a center Estimating Speed. One of method for RBF center estimation is using k-means clustering. The performance of RBFE is depends on the estimation ability of the RBF center. We Propose a RBF Equalizer using modified k-means clustering algorithm (MKMC) to speed up channel estimation and to reduce complexity of calculation. Computer simulations are included to illustrate the analytical results. It is shown that a discussed method improves about 1 dB via less training data.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.96-98
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• 2005

This paper presents a new two-phase linear hybrid stepping motors (LHSM), which has two windings per phase and one of them shares the other phase winding. The proposed motor shows a unique ability to deliver low cogging force without any particular complex control scheme and additional power electronics hardware in micro stepping control. An analytical and experimental comparison between conventional and proposed LHSM is evaluated to confirm the effectiveness of the proposed design.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.213.2-213.2
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• 2003

A simple analytical procedure using FT-NIR for the rapid determination of individual ingredients was evaluated. Direct measurements were made by reflection using a reflectance accessory, by transmittance using tablet accessory and turn table. FT-NIR spectral data were transformed to the first derivative. Partial Least Square Regression(PLSR) was applied to quantify near-infrared (NIR) spectra of 2 ingredients. These calibration models were cross-validated (leave-one-out approach). The prediction ability of the models was evaluated on ambroxol tablets and compared with the real values in manufacturing procedure. (omitted)

• 한국산업보건학회지
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• 제28권1호
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• pp.108-116
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• 2018

Objectives: This study investigated to the analytical work environment, analyst's expert and status of analytical instrument in the designated organization's laboratory for measuring work environment, and carried out to ensure reliability of analytical results. Methods: This study was conducted by 114 analysts who work in designated organization's laboratory for measuring work environment. Information on the working environment and personal characteristics of the analysts were collected using a self-reported questionnaire and were analyzed using the SPSS program through analysis of frequency and t-test. Results: The speciality of subjects was occupational health(57.0%), environmental health(38.6%) and environmental engineering(4.4%), and they had a higher level of academic ability than workers in other industries. Analysts had to handle a large number of sample analysis and many tasks other than analytical work. The analysts answered that it was difficult to analyze organic substances than inorganic substances, and the difficult parts were the analytical methods setting of new substances(55.3%), instrument analysis(24.6%) and principle of analysis(23.7%). Analytical instruments mainly have legally required instruments. The difficulty of the analysis is solved from the senior analyst in the laboratory and analytical information is mainly exchanged through seminar organized by the Association of Occupational Health Analysts. The analysts who are planning to move or considering the company were 48.2%, and the reasons for moving the company were difficult to work(14.0%), low salary(9.6%), employment type(8.8%) and job stress(7.0%). Conclusions: The conclusions of our study were that it was possible to secure reliability by solving the problems such as implementing professional education to improve expertise of analysts, strengthening analytical instruments through institutional improvement and improving work environment.

• 과학교육연구지
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• 제42권3호
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• pp.352-370
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• 2018

이 연구의 목적은 Peer Instruction의 지속적 활용이 초등학교 3학년 학생들의 과학 수업참여도와 토론 능력의 신장에 어떤 영향을 미치는지 살펴보고자 이루어졌다. 수업 주제와 관련된 선다형 문항을 활용하여 이루어지는 토론식 수업인 Peer Instruction이 3학년 과학 교과의 전차시의 수업에 대하여 6개월 동안 지속적으로 적용이 이루어졌고, 과학 수업참여도와 토론 능력을 조사하여 그 신장 정도를 알아보았다. 그 결과, 수업참여도 5개 영역인 수업준비하기, 수업활동하기, 의사표현하기, 수업확장하기, 수업열정, 모두에 대하여 통계적으로 유의한 효과를 나타내었음은 물론, 토론 능력 6개 영역인 논리력, 분석력, 듣기능력, 수용성, 규칙성, 적극성 영역에 대해서도 통계적으로 모두 유의한 효과를 보이는 것으로 나타나, Peer Instruction의 적용은 초등학교 3학년 학생들의 수업참여도와 토론 능력의 변화에 매우 긍정적인 영향을 미치는 것으로 확인되었다.

• 분석과학
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• 제9권2호
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• pp.161-167
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• 1996

이성분계 첨가물을 이용한 카드뮴 석출과 수소 생성의 상대족인 속도를 조절할 수 있는 가능한 방법에 대하여 조사하였다. 수소를 발생하는 물의 전기환원을 억제하는 소수성 필름을 형성할 수 있는 벤질 알코올을 첨가제 중의 하나로 선택하였다. 다른 한 가지 첨가제는 카드뮴(II) 이온의 친수성을 약화시킴으로써 소수성 벤질 알코올 필름층을 쉽게 가로질러 환원극에 전착시킬 수 있는 것을 선택하였다. 전압 전류 효율 연구로부터 이온쌍과 착물 첨가제가 벤질 알코올 필름 존재하에서 카드뮴의 환원을 촉진시킬 수 있다는 것을 확인하였다. 벤질 알코올 필름은 나트륨 이온과 카드뮴의 염화착물을 형성하는 이온쌍을 얻기에 충분하도록 전극 주위의 유전상수를 낮추고, 카드뮴의 환원을 촉진시킨다. 이러한 환원의 촉진은 염화물이 존재하지 않는 황산염 용액에서는 일어나지 않는다. 왜냐하면 카드뮴은 본래 아쿠아 착물과 이온쌍으로 존재하여 카드뮴의 환원을 촉진시키지 못하고 환원을 방해시키기 때문이다.

• Geomechanics and Engineering
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• 제5권5호
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• pp.379-399
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• 2013

In practice, analysis of laterally loaded piles is carried out using beams on non-linear Winkler springs model (often known as p-y method) due to its simplicity, low computational cost and the ability to model layered soils. In this approach, soil-pile interaction along the depth is characterized by a set of discrete non-linear springs represented by p-y curves where p is the pressure on the soil that causes a relative deformation of y. p-y curves are usually constructed based on semi-empirical correlations. In order to construct API/DNV proposed p-y curve for clay, one needs two values from the monotonic stress-strain test results i.e., undrained strength ($s_u$) and the strain at 50% yield stress (${\varepsilon}_{50}$). This approach may ignore various features for a particular soil which may lead to un-conservative or over-conservative design as not all the data points in the stress-strain relation are used. However, with the increasing ability to simulate soil-structure interaction problems using highly developed computers, the trend has shifted towards a more theoretically sound basis. In this paper, principles of Mobilized Strength Design (MSD) concept is used to construct a continuous p-y curves from experimentally obtained stress-strain relationship of the soil. In the method, the stress-strain graph is scaled by two coefficient $N_C$ (for stress) and $M_C$ (for strain) to obtain the p-y curves. $M_C$ and $N_C$ are derived based on Semi-Analytical Finite Element approach exploiting the axial symmetry where a pile is modelled as a series of embedded discs. An example is considered to show the application of the methodology.

• 문화기술의 융합
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• 제6권2호
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• pp.397-407
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• 2020

본 연구는 간호대학생의 핵심역량인 시뮬레이션 기반 실습 교육이 눈치, 문제해결 능력, 회복 탄력성에 미치는 효과를 알아보기 위해 시도되었다. 연구 결과 눈치의 하위변인 눈치 파악이 유의미하게 증가하였고, 문제해결 능력과 하위변인 문제 인식, 정보수집, 분석능력, 확산적 사고, 의사결정, 기획력, 실행과 모험 감수, 평가, 피드백에 유의미하게 증가하였다. 회복 탄력성과 하위변인 통제성, 긍정성, 사회성이 유의미하게 증가하였다. 이러한 결과는 시뮬레이션 기반 실습 교육이 간호 대학생의 핵심역량을 강화할 수 있다는 것이므로 현장감 있는 실습 모듈 개발을 위한 기반이 마련되어야 할 것이다.