• 한국환경보건학회지
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• 제46권1호
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• pp.96-102
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• 2020

Objectives: This study identified factors impacting radiation knowledge among aircrew, who are affected by cosmic radiation exposure due to their occupational environment. Methods: In September 2019 we conducted an online survey of aircrew through a Google link. We evaluated the level of radiation knowledge using a ten-item (10 points) questionnaire. The following exploratory variables were evaluated in relationship with the level of radiation knowledge using univariable linear regression models: sex, age, duration of employment, position level, company, marriage, education level, personal/family history of disease, and the number of times acquiring information on radiation through various channels (internet searching, watching television, reading newspaper, conversation about radiation with aircrew/non-aircrew, in-house training). With a p of 0.2 in univariable models, we built a multivariable linear regression model using a stepwise selection method. Results: The average radiation knowledge score of the 356 respondents was 7.22. Univariable linear regression analysis showed that radiation knowledge of the aircrew was associated with their company, position level, age, and number of conversations with other aircrew members. Our multivariable model showed that the radiation knowledge level of aircrew decreased as they had more conversations about radiation with other aircrew members and as their age increased. Conclusions: Korean air crew showed a lower level of radiation knowledge as their age and the number of conversations with colleagues increased. The study suggests that more education is needed in order for aircrew to gain accurate radiation knowledge.

• 응용통계연구
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• 제31권4호
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• pp.475-484
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• 2018

감마 일반화 선형모형은 음이 아니며 치우침이 있는 반응변수에 유용한 모형으로 알려져 있다. 그러나 포아송 분포 또는 이항 분포에 기반한 일반화 선형모형에 비해 적은 관심을 받아왔다. 특히, 회귀계수의 유의성 검정에 대해서는 연구가 면밀히 되어 있지 않다. 본 논문에서는 감마 일반화 선형 모형의 검정에 대해 다양한 통계량들을 알아보고 수치 연구를 통해 그들의 성능을 비교한다. 수치 실험의 결과 부분 이탈도 검정 방법의 문제점이 나타났으며, 가능도비 검정 방법과 F-검정 방법이 좋은 성능을 보임을 확인하였다.

• 한국의학물리학회지:의학물리
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• 제1권1호
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• pp.75-84
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• 1990

We have claculated the absorbed dose distributions in water phantom irradiated by high energy photon beam. PDD (Percent Depth Dose) and Beam Profile can be represented by functions of depths and distances by using one dimensional model model based on transport theory. The parameters on scattering and absorption are evaluated by using non-linear regression process method. The values neeessary for calculation are obtained by simple experiment. The calculated values are in good agreement with the measured values.

• 한국염색가공학회지
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• 제11권5호
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• pp.38-43
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• 1999

A calculation method of optimum parameters on dual adsorption isotherm system was examined. The optimum parameters were obtained by non-linear regression analysis based upon a limited solute concentration of dual adsorption isotherm. The results were analyzed with adducing experimental data of formerly reported treaties. The percentage mean deviation of dual adsorption equation calculated with optimum parameters was less than about 5% of experimental data, which was far less than results obtained with parameters of the adduced treatises.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.189-192
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• 2006

This study was performed to suggest the mediocre prediction equation of chloride diffusion coefficient which is used to estimate the service life of marine concrete, in order to provide the useful data for concrete mix design of marine concrete. As a result, the mediocre prediction equation of chloride diffusion coefficient which set W/B and mineral admixture replacement ratio as parameters was presented by performing the multivariate non linear regression analysis.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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• pp.861-864
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• 1993

This research provides the results of a trial to generate the chaos by using nonlinear function constructed by fuzzy inference rules. The chaos generation function or chaotic behavior can be obtained by using Takagi-Sugeno fuzzy model with some constraint of the relationship of its parameters. Two examples are shown in this research. The first is simple example that construct of logistic image by fuzzy model. The second is more complicated one that provide the chaotic time series by non-linear autoregression based on fuzzy model. Simulated results are shown in these examples.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전력기술부문
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• pp.491-493
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• 2003

Load foretasting model used generally such as times series and econometric regression model often doesn't reflect the load characteristics of small remote islands. Therefore, in this paper load demand forecast is peformed using EGARCH-M non-linear forecasting model.

• Journal of the Korean Data and Information Science Society
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• 제20권2호
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• pp.293-299
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• 2009

이 논문에서는 대구 두 개 동의 시간별 오존농도를 예측하는 모형으로 회귀, 자기회귀누적이동평균, 자기회귀누적이동평균 오차를 가지는 회귀 같은 선형모형들을 고려하였다. 평균제곱오차제곱근에 근거하여 보았을 때 한 개 동에서는 자기회귀누적이동평균 모형이 최적의 모형으로 선택되었고, 다른 동에서는 자기회귀누적이동평균 오차를 가지는 회귀 모형이 최적 모형으로 선택되었다. 이 최적의 모형으로부터 나온 잔차들의 변동석 분석을 수행하였는데 이를 통해 120 ppb를 넘는 오존 주의보 날짜를 예측하였다. 2000년에서 2003년까지의 훈련용 자료에 근거하여 보았을 때 잔차값의 경계값으로 35 ppb를 잡았을 때 오존주의보 날짜를 예측하는데 좋은 결과를 보였다. 하나의 동에서는 2004년의 오존주의보가 발령된 이틀 중 하루와 나머지 주의보가 발령되지 않은 364일을 모두 정확히 예측하였다. 다른 동에서는 2004년의 오존주의보가 발령된 하루와 주의보가 발령되지 않은 365일을 모두 정확히 예측하였다.

• 한국학교ㆍ지역보건교육학회지
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• 제19권1호
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• pp.99-109
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• 2018

Objectives: The study was conducted to understand job stress and fatigue conditions by dividing nurses in a polyclinic-level public medical institution, Seoul with more than 600 beds into ward nurses and non-ward nurses and to comprehend sub-areas of job stress that affect fatigue. Methods: A survey was conducted from August 18 2014 to September 12 2014, so 216 cases were analyzed by using PASW statistics 18.0. Results: Job stress of ward nurses is significantly high in the psychological burden of nursing service area and medical limit. Fatigue of ward nurses is also higher. As a result of multiple Linear regression, nursing service area affects fatigue of ward nurses and there is no significant influence factors in non-ward nurses. Conclusion: Therefore, mental health education and interest of hospital in nursing service area are more needed for ward nurses with high job stress and fatigue among nurses.

• Journal of Korean Society for Atmospheric Environment
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• 제9권E호
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• pp.358-363
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• 1993

Total particulate mater (TPM), $NO_2$ and $NH_3$ were measured simultaneously in the smoking and non-smoking locations during an eleven month period from March 1986 to January 1987 at three sites in Chicago : Illinois Institute of Technology Cafeteria, Rush-Presbyterian St. Lukes Medical Center Cafeteria and a downtown office building. From this study, the mean concentrations of $NO_2$ and $NH_3$ were not significantly different between the smoking and non-smoking locations at any sampling site ; however, there was a statistical difference for TPM between the smoking and non-smoking locations. Activity factor was useful for describing the contribution from indoor source. The linear regression analysis was reasonable method for discriminating the individual contribution of source to determine the emission factor. The TPM emission factor determined from this technique was in good agreement with value from the literature.