• 한국산업보건학회지
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• 제25권2호
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• pp.184-193
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• 2015

Objectives: This study focused on three aspects: characterizing concentrations of airborne particles by size distributions and asbestos fibers generated by various building materials; analyzing the characteristics of fibers produced by each simulation and asbestos fibers released from ACBMs; and investigating correlations of airborne asbestos fibers and particles generated and association of particle and asbestos concentrations. Methods: We selected three ACBMs including an insulation board, cement asbestos slate and wallboard. We constructed 4 scenarios; a) crushing with a hammer; b) cutting with a industrial knife; c) brushing with a metal brush; and d) tightening & loosening with a hand drill. We implemented one simulation for 30 seconds followed by 30 seconds resting period. We repeated a total of 5 cycles for 5 minutes. Results: The highest concentration of particulate & fibrous matters was from crushing with a hammer in each scenario followed by brushing with a metal brush, cutting with a industrial knife, and tightening & loosening with a hand drill. For ACBMs studied, asbestos concentrations were highest from an insulation board followed by cement asbestos slate, and wallboard. No difference in terms of concentration was found between an insulation board and asbestos slate. Fibers with $5{\sim}20{\mu}m$ in length were included in 76~90% of total fibrous matters. The distribution of the straight form fibers was greater than that of the curl form. About 90% of $PM_{Total}$ released from ACBMs was consisted of $PM_{10}$ while only 10% of $PM_{Total}$ was $PM_{2.5}$. Particulate matters like $PM_{2.5}$ was significantly correlated with fibrous matters($R^2=0.81$). Conclusions: We found ACBMs can significantly release asbestos fibers as well as $PM_{2.5}$. Concentrations of asbestos generated by ACBMs were well correlated with $PM_{2.5}$.

• 한국콘텐츠학회논문지
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• 제16권4호
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• pp.516-527
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• 2016

본 연구의 목적은 시뮬레이션 수업 후 Lasater의 임상판단 루브릭을 이용한 디브리핑이 간호학생의 비판적 사고성향, 문제해결능력과 임상판단력에 미치는 효과를 검증하는 것이다. 비동등성 대조군 전후 시차설계를 이용한 실험연구이며, 연구대상은 12그룹 60명으로 무작위로 실험군 (n=30)과 대조군 (n=30)을 배정하고, 실험군에게는 시뮬레이션 교육과 Lasater의 임상판단 루브릭을 적용한 디브리핑을 실시하고, 대조군에게는 구조화된 도구를 사용하는 것이 아니라 질문과 피드백으로 이루어진 일반적 디브리핑을 실시하였다. 자료수집은 2015년 6월 15일부터 6월 22일까지 이루어졌으며 비판적 사고성향과 문제해결능력은 자가보고형 설문지를 이용하여 측정하였고 임상판단력은 Lasater의 임상판단 루브릭으로 측정하였다. 연구결과 비판적 사고성향은 실험군은 실험 전 $3.5{\pm}1.4$점에서 실험 후 $3.6{\pm}1.3$점, 대조군은 실험 전 $3.5{\pm}1.4$점에서 실험 후 $3.4{\pm}1.2$점(t=1.86, p= .022), 문제해결능력은 실험군은 실험 전 $3.4{\pm}1.6$점에서 실험 후 $4.0{\pm}1.8$점, 대조군은 실험 전 $3.5{\pm}1.5$점에서 실험 후 $3.6{\pm}1.6$점(t=3.21, p=< .011) 및 임상판단력은 실험 후 실험군은 $11.5{\pm}1.7$, 대조군은 $9.3{\pm}2.3$(t=4.14, p=< .001)으로 실험 후 비판적 사고성향, 문제해결능력, 임상판단력 모두 실험군이 대조군보다 통계적으로 유의하게 높게 나타났다. 이를 통해 Lasater의 임상판단 루브릭을 이용한 디브리핑은 임상판단력을 향상시키는데 유익하므로 시뮬레이션교육에서 Lasater의 임상판단 루브릭을 사용하는 디브리핑이 필요하다고 사료된다.

• 한국대기환경학회지
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• 제33권2호
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• pp.139-158
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• 2017

CMAQ (Community Multiscale Air Quality Model) simulations were carried out to estimate the potential range of contributions on surface $PM_{2.5}$ concentrations over the Seoul Metropolitan Area (SMA) with the gaseous precursors and Primary Particulate Matters(PPM) available from a recent national emissions inventory. In detail, on top of a base simulation utilizing the 2013 Clean Air Policy Supporting System (CAPSS) emission inventory, a set of Brute Force Method (BFM) simulations after reducing anthropogenic $NO_x$, $SO_2$, $NH_3$, VOCs, and PPM emissions released from area, mobile, and point sources in SMA by 50% were performed in turn. Modeling results show that zero-out contributions(ZOC) of $NH_3$ and PPM emissions from SMA are as high as $4{\sim}5{\mu}g/m^3$ over the region during the modeling period. On the contrary, ZOC of local $NO_x$ and $SO_2$ emissions to SMA $PM_{2.5}$ are less than $1{\mu}g/m^3$. Moreover, model analyses indicate that a wintertime $NO_x$ reduction at least up to 50% increases SMA $PM_{2.5}$ concentrations, probably due to increased HNO3 formation and conversion to aerosols under more abundant ozone and radical conditions after the $NO_x$ reduction. However, a nation-wide $NO_x$ reduction decreased SMA $PM_{2.5}$ concentrations even during winter, which implies that nation-wide reductions would be more effective to curtail SMA $PM_{2.5}$ concentrations than localized efforts.

• 한국입자에어로졸학회지
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• 제5권4호
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• pp.171-178
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• 2009

$PM_{2.5}$ is one of critical air pollutants due to its high absorbability of heavy metallic fumes, PAH and bacillary micro organisms. Such a fine particulate matter is often formed through various nucleation processes including condensation. This study attempts to find the nucleation behaviors of $PM_{2.5}$ arisen from coal power stations using a classical heterogeneous Fletcher's theory. The numerical simulation by C-language could approximate the nucleation process of $PM_{2.5}$ from water vapor, of which approach revealed the required energy for embryo formation and embryo size and nucleation rate. As a result of the calculation, it was found that wetting agents could affect the particle nucleation in vapor condensation. In particular, critical contact angle relates closely with the vapor saturation. Particle condensation could be reduced by lowering the angles. The wetting agents aid to decrease the contact angle and surface tensions, thereby may contribute to save the formation energy.

• Child Health Nursing Research
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• 제20권4호
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• pp.294-303
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• 2014

목적 본 연구의 목적은 간호대학생의 비판적 사고성향과 문제해결과정 정도 및 시뮬레이션 기반 임상수행능력 평가 점수와의 상관관계를 파악하는 데에 있다. 방법 본 연구의 대상자는 일 간호대학 3학년 학생 214명으로 대상자의 비판적 사고성향과 문제해결과정 정도 및 시뮬레이션 기반 임상수행능력 평가 점수와의 관계를 파악하였다. 비판적 사고성향은 Yoon (2008)이 개발한 5점 척도의 도구를 사용하여 측정하였고, 문제해결과정 정도는 Lee 등(2008)가 개발한 5점 척도의 문제해결과정 측정도구, 시뮬레이션 기반 임상수행능력 평가는 연구자가 개발한 체크리스트를 사용하였다. 수집된 자료는 SPSS WIN 18.0 프로그램을 이용하여 기술통계, Pearson's correlation coefficients를 이용하여 분석하였다. 결과 간호대학생의 비판적 사고성향 정도는 $3.76{\pm}0.46$ (점수범위 1-5점), 문제해결과정 정도는 $3.67{\pm}0.47$ (점수범위 1-5점)으로 중간 이상의 점수를 보였다. 시뮬레이션 기반 임상수행능력 평가 점수는 비판적 사고 성향이 평균점수(3.67점) 이상으로 높은 간호대학생에게서 유의하게 높게 나타난 반면, 문제해결과정 정도와의 유의한 상관관계는 없는 것으로 조사되었다. 비판적 사고성향은 시뮬레이션 기반 임상수행능력 평가의 하부 영역 중 간호사정 영역에서 유의한 상관관계가 있는 것으로 나타났다. 결론 본 연구는 시뮬레이션 기반 학습은 간호학생들의 비판적 사고성향이 기반이 되어야 하며 비판적 사고 성향정도는 복합적인 상황에서 대상자의 상태를 파악하는 간호사정에서 긍정적 영향을 미친다는 근거를 제시하였다. 그러므로 간호대학생의 비판적 사고함양을 위한 지속적인 교육이 필요하다. 또한 시뮬레이션 기반 학습은 학습자의 이러한 강점과 약점을 고려하여 시뮬레이션 평가 전 단계에서 충분한 학습의 기회를 제공함으로써 질적으로 우수한 간호사에 대한 요구가 증대되는 현 시점에 효과적인 대응책이 될 수 있을 것이다.

• Journal of Preventive Medicine and Public Health
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• 제30권3호
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• pp.530-539
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• 1997

This study was conducted to assess the health risk on the volatile organic compounds such as toluene, xylene, and styrene in painting workplace. It was monitored through personal air sampling during working time in selected 5 workplaces and analysed using gas chromatography. For the settlement of exposure situation, there were regarded working conditions such as working hours, yearly working days, and working years. Also, Monte-Carlo simulation was used for the induction of hazard index using toxicity value from IRIS(Integrated risk information system) database. The results of risk assessment were summarized as follows. 1. The air concentration of toluene was $7.096{\pm}15,644ppm,\;2.586{\pm}4.275ppm\;for\;xylene,\;1.914{\pm}5.320ppm$ for styrene in blast painting workplaces. The level of toluene was different significantly compared with the level of xylene and styrene. 2. Computated chronic daily intake values of 95th percentile on toluene, xylene and styrene treated by Monte-Carlo simulation were 9.616, 3.567, 2.782 mg/kg/day, respectively. 3. Computated hazard index values of 75th percentile on toluene, xylene and styrene treated by Monte-Carlo simulation were 3.5, 1.0 and 1.6, respectively. Adverse health effects on the toluene, xylene and styrene would be expected by working exposure in selected 5 workplaces since the hazard indices of three compounds were exceeded 1 in the surroundings of 75th percentile though having the low emerged frequency.

• 제어로봇시스템학회논문지
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• 제15권5호
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• pp.543-547
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• 2009

This paper describes the design, simulation, development, and experiment of a six degree-of-freedom micropositioning parallel manipulator. A movable stage was supported with six links, each of which extends with a dc-servo micropositioning actuator. In case of parallel manipulator, while the solution of the inverse kinematics is easily found by the vectors of the links which are composed of the joint coordinates in base and platform, but forward kinematic is not easily solved because of the nonlinearity and complexity of the parallel manipulator's kinematic output equation with the multi-solutions. The movable range of the prototype was ${\pm}25mm$ in the x- and y-directions and ${\pm}12.5mm$ in the z-direction. The minimum incremental motion of the prototype was $1{\mu}m$ in the x- and y-directions and $0.5{\mu}m$ in the z-direction. The repeatability of the prototype was ${\pm}2{\mu}m$ in the x- and y-directions and ${\pm}1{\mu}m$ in the z-direction. The motion performance was also evaluated by not only the computer simulation of CAD model but also the experiment using a capacitive sensor system.

• 환경영향평가
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• 제24권5호
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• pp.456-471
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• 2015

배출량 자료는 대기질 수치모의에 있어서 큰 영향을 주는 요소로서 정확한 대기질 수치모의를 위해서 배출량 자료의 정확성과 신뢰도 향상은 대기질 모델 연구에 있어 필수적이다. 본 연구에서는 울산지역을 대상으로 2003년과 2010년 CAPSS 배출량 자료인 CAPSS-2003과 CAPSS-2010를 입력자료로 하여 WRF-CMAQ 모델을 수행하여 울산지역 배출량 지료의 타당성을 검토하였다. 우선 오염물질의 장거리 수송 영향을 배제하기 위하여 울산지역 자체 내의 배출량 영향이 우세한 종관 기상조건을 가진 사례일을 선정하고 선정된 사례일에 대해서 WRF-CMAQ모델을 수행한 후 그 결과인 CO, $NO_2$, $SO_2$, $PM_{10}$ 농도와 관측 값을 비교하여, 과소 혹은 과대 모의되는 정도를 분석하여 모의결과를 보정 할 수 있는 'scaling factor'를 제시하였다. 그 결과 CAPSS-2003을 이용한 모의결과는 CO와 $NO_2$에 대해서는 관측과 유사한 수준으로 모의하였으나 $SO_2$는 약 12배 과대모의, $PM_{10}$은 약 27배나 과소모의하는 결과를 얻었다. 반면 CAPSS-2010을 이용한 모의결과에서는 CO와 $NO_2$의 모의결과는 유사하였으며, $SO_2$는 약 2배 과대모의, $PM_{10}$은 약 5배 과소모의 하여 $SO_2$와 $PM_{10}$ 배출량이 상당히 개선됨을 확인하였다. $SO_2$와 $PM_{10}$ 역시 이전 보다는 관측에 가깝게 모의되었으나 현실적 모델링 결과를 도출하기 위해서 배출량은 향후 개선되어야 할 부분으로 판단되었다. 따라서 보다 현실적인 모델링 결과를 도출하기 위해서는 본 연구에서 제시한 울산지역 배출량의 'scaling factor'를 이용하면 보다 안정된 모델링 결과가 도출 될 것으로 판단된다.

• Safety and Health at Work
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• 제9권3호
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• pp.356-359
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• 2018

This case report attempts to present a case of acute toxic hepatitis in fire extinguisher manufacturing workers exposed to 2,2-dichloro-1,1,1-trifluoro-ethane (HCFC-123) in August 2017 in Korea. Twenty-two-year-old male workers were exposed to HCFC-123 for 1.5 hours one day and for 2.5 hours the other day, after which one worker died, and the other recovered after treatment. The workers were diagnosed with acute toxicity of hepatitis. However, exposure levels of HCFC-123 were not known with no work environment measurement done. Therefore, this study was conducted to estimate the exposure concentration of HCFC-123 via a job simulation experiment. In the simulation, the HCFC-123 exposure concentration was measured with the same working practice and working time as with the workers aforementioned. As a result, the workers who infused HCFC-123 into storage tanks were estimated to be exposed to HCFC-123 at a concentration of $20.65{\pm}10.81ppm$, and a mean concentration of area samples within a working radius were estimated as $70.30{\pm}18.10ppm$. Valve assembly workers working on valves of a fire extinguisher filled with HCFC-123 were exposed to HCFC-123 at concentrations of $91.65{\pm}4.03ppm$ and $115.55{\pm}7.28ppm$, respectively, in the simulation, and area samples simulated within the working radius were also found to be high with concentrations of $122.75{\pm}91.15ppm$ and $126.80{\pm}60.25ppm$, respectively. Nitrogen gas packing workers, who did not handle HCFC-123 directly, were exposed to the agent at a concentration of $71.80{\pm}8.49ppm$. These results suggest that exposure to HCFC-123 at high concentrations for 1.5-2.5 hours caused acute toxic hepatitis in two workers.

• 중환자간호학회지
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• 제8권2호
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• pp.23-32
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• 2015

Purpose: The purpose of this study was to analyze the effects of simulation-based training on nursing students' knowledge and ability to perform advanced cardiovascular life support. Methods: A nonequivalent control group non-synchronized design was used. The participants were, in total, 59 junior college nursing students (experimental group: 30, control group: 29). The data were analyzed with a ${\chi}^2$-test, independent t-tests, and analysis of covariance (ANCOVA) using IBM SPSS Statistics 23 program. Results: The experimental group ($80.8{\pm}8.4$), who received simulation-based advanced cardiovascular life support education, showed a higher level of knowledge of advanced cardiovascular life support than the control group ($75.0{\pm}9.9$), who received lecture-based education. In addition, the experimental group ($106.4{\pm}11.9$) showed a higher level of ability to perform advanced cardiovascular life support than the control group ($86.5{\pm}9.9$). Conclusion: Simulation-based advanced cardiovascular life support education was more effective for increasing the knowledge and performance ability of college students than lecture-based education. Therefore, simulation-based training should be used to improve the knowledge and ability of nursing students and should be applied with reinforced systematic education programs.