• Geomechanics and Engineering
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• 제35권5호
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• pp.499-509
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• 2023

The objective of this study is to perform outlier analysis to obtain the distribution of groundwater levels through the best model. The groundwater levels are measured in 10, 25 and 30 piezometers in Seoul, Daejeon and Suncheon in South Korea. Fifty-eight empirical distribution functions were applied to determine a suitable fit for the measured groundwater levels. The best fitted models based on the measured values are determined as the Generalized Pareto distribution, the Johnson SB distribution and the Normal distribution for Seoul, Daejeon and Suncheon, respectively; the reliability is estimated through the Anderson-Darling method. In this study, to choose the appropriate confidence interval, the relationship between the amount of outlier data and the confidence level is demonstrated, and then the 95% is selected at a reasonable confidence level. The best model shows a smaller error ratio than the GEV while the Mahalanobis distance and outlier labelling methods results are compared and validated. The outlier labelling and Mahalanobis distance based on median shown higher validated error ratios compared to their mean equivalent suggesting, the methods sensitivity to data structure.

• Journal of Preventive Medicine and Public Health
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• 제47권5호
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• pp.266-272
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• 2014

Objectives: The aim of this study was to investigate the relationship between age at cigarette smoking initiation and smoking level among adolescent current smokers. Methods: In 2007, students from one or two classes of the 10th or 11th grade were randomly selected using the probability proportional to size sampling method. In total, 743 current smokers were included. Multiple logistic regression was used to determine the association between age at smoking initiation and smoking level as either frequent, daily, or heavy smokers. Results: The adjusted odds ratios for each smoking level were significantly higher for younger ages of smoking initiation than those for older ages of initiation were (p for trend <0.001). Compared with the students who started smoking in grades 10 to 11, the adjusted odds ratios for frequent, daily, and heavy smokers increased from 2.24 (95% confidence interval [CI], 1.30 to 3.87) to 3.90 (95% CI, 2.02 to 7.56), from 1.56 (95% CI, 0.92 to 2.62) to 3.17 (95% CI, 1.70 to 5.92), and from 2.56 (95% CI, 1.21 to 5.42) to 5.67 (95% CI, 2.61 to 12.30) with younger ages of smoking initiation. Conclusions: Smoking frequency and amount were closely associated with age at smoking initiation. Therefore, smoking prevention programs should be initiated from the young adolescent period.

• 성인간호학회지
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• 제28권6호
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• pp.659-668
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• 2016

Purpose: This study utilized secondary data and investigated the factors associated with life satisfaction by living arrangements among community-dwelling adults aged 65 years or older in Korea. Methods: A total of 2,134 participants were selected from the 2014 Korean Longitudinal Study of Aging (KLoSA). Univariable and multivariable logistic regression were used for data analysis. Results: The significant factors associated with life satisfaction in older adults living with others were education level (odds ratio [OR] 1.73, 95% confidence interval [CI] 1.41~2.11), place of residence in medium-size city (OR 1.57, 95% CI 1.25~1.97), place of residence in rural town(OR 1.52, 95% CI 1.19~1.95), depression (OR 2.99, 95% CI 2.43~3.68), frequency of contact with neighbors (OR 1.39, 95% CI 1.10~1.76), and social participation (OR 1.48, 95% CI 1.14~1.93). In contrast, factors associated with life satisfaction among older adults living alone were education level (OR 1.93, 95% CI 1.15~3.24) and depression (OR 2.49, 95% CI 1.48~4.19). Conclusion: These findings indicated that nursing interventions for improving life satisfaction among older adults should take into account their specific living arrangements.

• 한국지능시스템학회논문지
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• 제15권5호
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• pp.533-537
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• 2005

리커트 척도는 어떤 의도의 질문에 대한 동의를 수치적으로 나타내는 방법으로서 주로 5점 척도를 많이 사용하나 여러번 질문에서 응답자체가 애매성을 가지고 있다. 본 연구에서는 3점 척도의 응답의 애매성을 5점 척도의 멤버쉽 함수로 나타낸 후 한 항목의 응답의 95% 신뢰구간을 다시 멤버쉽함수로 하여 그 데이터를 퍼지가설검정하였다.

• 터널과지하공간
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• 제7권1호
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• pp.51-57
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• 1997

This study provides the results of two different blasting methods applied at the H Telcon construction site in Yeon-dong, Cheju Island. One is the traditional blasting method without bottom-hole stemming and the other with bottom-hole stemming using the materials such as sand, polystyrene and sawdust in 5~10 cm lengths. The effect of these materials on vibration level was studied. Assuming that safety criterion of vibration level be 0.5cm/set, 95% confidence limit line of measured data shows that maximum charge weight per delay could be increased in the following order; traditional methed, polystyrene stemming, sand stemming, sawdust stemming.

• 한국진공학회지
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• 제14권2호
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• pp.59-68
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• 2005

부피가 다른 세 개의 진공용기를 조합하여 정적법 (static expansion method)을 이용한 중진공영역의 국가표준기를 개발하였다. 이 장치를 이용하여 133pa 범위의 용량형 진공게이지 (capacitance diaphragm gauge)를 교정하여 국제표준화기구의 측정불확도 표현지침에 따라 분석하였다. 그 결과 표준압력 0.553Pa에서의 확장불확도 (expanded uncertainty)가 95% 신뢰수준 (confidence level), 포함인자 (coverage factor) k=2에서 $2.628\times10^{-3}Pa$로 우수한 성능을 보였다.

• 동서간호학연구지
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• 제26권1호
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• pp.91-99
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• 2020

Purpose: The study aims to assess the inter-rater reliability of the Korean Triage and Acuity Scale between the research nurses and the triage nurses. Methods: Interrater reliability was measured on 400 adult (≧15) and 400 pediatric (<15) patients who visited the emergency medical center from January 4 to June 30, 2018. Results: The study result showed that the inter-rater reliability of the Korean Triage and Acuity Scale was substantial, with κ=.73 (95% Confidence interval= .68-.78) and 77.0 percent agreement. The inter-rater of Pediatric Korean Triage and Acuity Scale was also substantial, with κ=.76 (95% Confidence interval= .71-.82) and 83.8 percent agreement. Conclusion: Although the inter-rater reliability of the Korean Triage and Acuity Scale was acceptable, the percent agreement was lower than the desirable level (<80.0%). It was confirmed that Pediatric Korean Triage and Acuity Scale had an acceptable level of inter-rater reliability and percent agreement for clinical use. Efforts should be made to improve the reliability in the future.

• Nuclear Engineering and Technology
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• 제56권2호
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• pp.762-769
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• 2024

The TMSR-SF0 simulator is an integral effect thermal-hydraulic experimental system for the development of thorium molten salt reactor (TMSR) program in China. The simulator has two heat transport loops with liquid FLiNaK. In literature, the 95% level confidence uncertainties of the thermophysical properties of FLiNaK are recommended, and the uncertainties of density, heat capacity, thermal conductivity and viscosity are ±2%, ±10, ±10% and ±10% respectively. In order to investigate the effects of thermophysical properties uncertainties on the molten salt heat transport system, the uncertainty and sensitivity analysis of the heat transfer characteristics of the simulator system are carried out on a RELAP5 model. The uncertainties of thermophysical properties are incorporated in simulation model and the Monte Carlo sampling method is used to propagate the input uncertainties through the model. The simulation results indicate that the uncertainty propagated to core outlet temperature is about ±10 ℃ with a confidence level of 95% in a steady-state operation condition. The result should be noted in the design, operation and code validation of molten salt reactor. In addition, more experimental data is necessary for quantifying the uncertainty of thermophysical properties of molten salts.

• 디지털융복합연구
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• 제14권2호
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• pp.279-286
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• 2016

최근 노인 인구의 증가로 노인들의 삶의 질과 관련하여 구강건강에 관한 관심도 크게 증가하고 있다. 본 연구의 목적은 치매, 치매의심, 정상인 세 그룹으로 나누어 여성 노인들의 잔존 치아 수와의 관련성에 대해서 조사하였다. 일부 지역사회에 거주하는 경로당을 방문한 60세 이상 여성 노인 177명의 구강 상태와 그들의 MMSE 점수로 인지기능을 평가하였다. 모든 자료는 SPSS를 이용하여 chi-square test, t-test, ANOVA, multiful logistic regression 통계기법을 이용하여 분석하였다. Multiful logistic regression으로 MMSE 점수에 따른 치매와 잔존 치아 수와의 관련성을 분석하였고, 95% 신뢰구간으로 정하였다. 치매가 있는 대상자가 잔존 치아수가 0-10개로 적을 위험비가 3.53배(95% confidence interval: 1.382-8.997) 높은 것으로 나타났다. 본 연구에서는 여성 노인들에서 MMSE 점수에 따른 치매와 잔존 치아 수 사이에 유의한 차이가 있는 것으로 조사되었다.

• 응용통계연구
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• 제27권4호
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• pp.645-653
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• 2014

p-값은 관측 표본과 관측 결과보다 심하게 대안가설의 방향으로 영가설을 이탈하는 표본들이 영가설 하에서 갖는 확률이다. p-값이 일정 ${\alpha}$(= 0:05)보다 작게 나타나면 연구자는 대안가설이 지지된 것으로 본다. 그런 경우라고 하더라도 그의 가설이 향후 연구에서 번복될 수 있는데 그 이유는 p-값이 표본에 따라 변동하는 통계량이기 때문이다. Boos와 Stefanski (2011)는 붓스트랩 방법으로 p-값의 예측분포를 구할 수 있음을 보였다. 그들은 그 분포의 상위 10-20% 분위수가 ${\alpha}$보다 작은가를 확인할 필요가 있음을 강조한다. 만약 그렇지 않은 경우에는 "지지"된 가설의 재현성이 문제될 수 있기 때문이다. 가설검정에서 일정 수준의 재현율을 확보하기 위해서는 표본의 증대가 요구된다. 이 연구는 k배 확대 붓스트랩 표본추출(boosted bootstrap sampling)로써 필요한 표본크기를 계산할 수 있음을 두 표본의 비교와 다중선형회귀의 수치 예에서 보인다. k 값을 정하기 위해서는 몇 차례 시행착오를 해야 하지만 계산적 부담은 크지 않다. 95% 신뢰구간은 독립적인 표본들로부터 같은 방식으로 산출되는 구간이 미지의 모수를 포함할 확률이 95%가 되도록 설정된다. 이 연구는 한 관측표본으로부터 얻어진 95% 신뢰구간 내 개별 점이 미래 연구의 신뢰구간에도 포함될 것인지 그 재현성을 붓스트랩 재표본들에서 평가한다. 이 연구는 개별 점에서 산출한 신뢰구간 재현율을 그래프로 보인다.