• 근관절건강학회지
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• 제29권1호
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• pp.41-49
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• 2022

Purpose: The purpose of this study was to assess the influence of nurses staffing level on patient health outcomes in intensive care units (ICUs) in Korea. Methods: The study was retrospective in nature. Information on patients and their outcomes, as well as nurse cohort data, were obtained from Korea's National Health Insurance Service Database. The observation period was from January 1, 2008 to December 31, 2018, and data for 2,964,991 patients were analyzed. Independent variables included patient' age and sex and hospital type, intensivist, and nurses staffing level. Results: The mortality rate in ICUs was significantly higher at tertiary hospitals with a level 3~4 (HR, 1.21; 95% confidence interval, 1.19~1.22) or level 5~9 nurse staffing (HR, 1.31; 95% confidence interval, 1.27~1.34) compare to that of tertiary hospitals with a 1~2 level. 28-day mortality rate was also higher at general hospitals with a level 3~4 (HR, 1.13; 95% confidence interval, 1.12~1.14), level 5~6 (HR. 1.34; 95% confidence interval, 1.32~1.36), level 7~9 nurse staffing (HR, 1.38; 95% confidence interval, 1.38~1.42), using level 1~2 as reference. Conclusion: Nurses staffing level is a key determinant of healthcare-associated mortality in critically ICUs patients. Policies to achieve adequate nurse staffing levels are therefore required to enhance patient outcomes.

• 대한교통학회지
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• 제13권1호
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• pp.167-183
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• 1995

The objective of study is to evaluate highway capaicty estimation alternative and to develop capacity from statistical distribution of observed traffic flow. Speed-Volume relation is analyzed from vehicle's headway distribution eliminating the long headway by confidence intervals 99%, 95%, 90%. Capacity estimate alternatives were evaluated from 95% , 90%, 85% level of cummulative distribution of observed hourly traffic flow adjusted to confidence intervals. The result of investigation revealed that maximum hourly rate of flow is 2, 130pcu at confidence interval of 995, 2, 233pcu at 95%, 2, 315pcu at 90% respectively. Compared to the capacity of 2, 200pcu per hour per lane used in HCM and KHCM(Korea Highway Capacity Manual), capa챠y appears to correspond to confidence interval of 95%. Using the traffic flow rate at confidence interval of 95% the maximum hourly flow rate is 2, 187pcu at 95% of cummulative volume distribution, 2, 153pcu at 90%, 2, 215pcu at 85%. The study suggests that raional capacity esimation alternative is to take the 95% of cummulative distribution of observed hourly traffic flow at 95% confidence headway interval eliminating 5% long headway.(i.e. 95-95 rule)

• International Journal of Reliability and Applications
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• 제7권2호
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• pp.177-186
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• 2006

Typical confidence intervals for a mean or mean residual life (MRL) are centered about the mean or mean residual life. We discuss novel confidence intervals that produce statements like "we are 95% confident that the MRL function, e(t), is greater than a prespecified $\mu_o$ for all t in the interval [0, $\hat{\theta})$)" where $\hat{\theta}$ is determined from the sample data, confidence level, and $\mu_o$. Also, we can have statements like 'we are 95% confident that the MRL of population 1, namely $e_1$(t), is greater than the MRL of population 2, $e_2$(t), for all t in the interval [0, $\hat{\theta}$)" where $\hat{\theta}$ is determined from the sample data and confidence level. We illustrate these one and two sample confidence intervals on internal bonds (tensile strengths) for an important modem engineered wood product, called medium density fiberboard (MDF), used internationally.

• 한국식품과학회지
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• 제44권6호
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• pp.658-665
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• 2012

본 연구는 시중 유통되고 있는 곡류가공품 중 zearalenone을 immunoaffinity column 및 LC-MS/MS를 이용해 분석하였다. 표준용액의 검량선은 1, 10, 50, 100, 250 ng/mL농도 범위에서 상관계수($r^2$) 0.999 이상으로 양호한 직선성을 보였고, 검출한계 및 정량한계는 각각 0.3, $1.0{\mu}g/kg$이었다. 회수율은 77.2-107.8%였고, RSD는 1.5-12.8이었다. Product ion 283 m/z으로 정량하여 분석한 결과 과자류 21건 중 1건(4.8%) $2.3{\mu}g/kg$, 옥수수가공품 9건 중 2건(22.2%) $1.6-8.5{\mu}g/kg$, 기타곡류가공품 14건 중 선식 1건(7.1%)에서 $3.4{\mu}g/kg$이 검출되었다. 미숫가루가 19건 중 6건(31.6%)이 검출되어, 최고 검출율을 나타냈으며, $1.1-29.7{\mu}g/kg$의 검출농도를 나타내어 다른 곡류가공품에 비해 높은 수준이었다. 총 시료 89건 중 10건에서 제랄레논이 검출되어 11.2%의 검출율을 보였고, 오염수준은 $1.1-29.7{\mu}g/kg$이었다. 검출시료 12건은 product ion 187 m/z으로 모두 제랄레논임을 확인하였다. 제랄레논을 측정하는 과정 중 불확도 인자를 파악하여 측정 불확도를 추정 한 결과 41.7, $166.7{\mu}g/kg$일때 보리차는 각각 $44.9{\pm}5.0{\mu}g/kg$(95% 신뢰수준 약 k=2), $128.7{\pm}7.9{\mu}g/kg$(95% 신뢰수준 약 k=2), 미숫가루는 각각 $30.7{\pm}5.8{\mu}g/kg$(95% 신뢰수준 약 k=2), $173.7{\pm}14.9{\mu}g/kg$(95% 신뢰수준 k=2.26), 과자는 $37.2{\pm}7.4{\mu}g/kg$(95% 신뢰수준 k=2.31), $151.0{\pm}10.4{\mu}g/kg$(95% 신뢰수준 약 k=2)를 나타내었다.

• 한국임상수의학회지
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• 제28권4호
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• pp.422-426
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• 2011

For a national survey in which wide geographic region or an entire country is targeted, multi-stage sampling approach is widely used to overcome the problem of simple random sampling, to consider both herd- and animallevel factors associated with disease occurrence, and to adjust clustering effect of disease in the population in the calculation of sample size. The aim of this study was to establish sample size for estimating bovine tuberculosis (TB) in Korea using stratified two-stage sampling design. The sample size was determined by taking into account the possible clustering of TB-infected animals on individual herds to increase the reliability of survey results. In this study, the country was stratified into nine provinces (administrative unit) and herd, the primary sampling unit, was considered as a cluster. For all analyses, design effect of 2, between-cluster prevalence of 50% to yield maximum sample size, and mean herd size of 65 were assumed due to lack of information available. Using a two-stage sampling scheme, the number of cattle sampled per herd was 65 cattle, regardless of confidence level, prevalence, and mean herd size examined. Number of clusters to be sampled at a 95% level of confidence was estimated to be 296, 74, 33, 19, 12, and 9 for desired precision of 0.01, 0.02, 0.03, 0.04, 0.05, and 0.06, respectively. Therefore, the total sample size with a 95% confidence level was 172,872, 43,218, 19,224, 10,818, 6,930, and 4,806 for desired precision ranging from 0.01 to 0.06. The sample size was increased with desired precision and design effect. In a situation where the number of cattle sampled per herd is fixed ranging from 5 to 40 with a 5-head interval, total sample size with a 95% confidence level was estimated to be 6,480, 10,080, 13,770, 17,280, 20.925, 24,570, 28,350, and 31,680, respectively. The percent increase in total sample size resulting from the use of intra-cluster correlation coefficient of 0.3 was 22.2, 32.1, 36.3, 39.6, 41.9, 42.9, 42,2, and 44.3%, respectively in comparison to the use of coefficient of 0.2.

• 한국산학기술학회논문지
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• 제18권4호
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• pp.408-417
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• 2017

본 연구의 목적은 의료기관 간호사 확보수준이 수술한 암환자의 원내 사망과 원내 감염에 어떠한 영향을 미치는지 알아보고자 하였다. 이차자료를 이용하였으며, 2012년 상반기에 260개 의료기관에서 수술 후 사망률이 높은 6개 암으로 수술받은 암환자 24,510명을 대상으로 하였다. 단순 로지스틱 회귀분석과 일반화추정방정식(GEE) 모형을 이용하여 분석하였다. 환자 및 의료기관 특성(기관 종별 유형, 소재지, 수술건수)을 보정 후, 사망 가능성은 간호사 확보수준 0-1등급에 비해 2-3등급 군(odds ratio [OR], 1.46; 95% confidence interval [CI], 1.00-2.11), 6-7등급 군(OR, 3.28; 95% CI, 1.87-5.74)에서 더 높은 것으로 나타났다. 병원 감염이 발생할 가능성은 간호사 1인당 침상수가 하나씩 증가할 때마다 증가하여, 0-1등급 군에 비해 2-3등급 군은 6.63배(95% CI, 3.00-14.62), 4-5등급 군은 5.79배(95% CI, 1.88-17.78), 6-7등급 군은 8.4배(95% CI, 1.82-38.84) 높은 것으로 나타났다. 낮은 간호사 확보수준은 환자안전과 의료의 질을 반영하는 지표인 높은 수술 후 원내 사망과 감염발생과 관련이 있었다. 이는 적절한 간호사 확보 수준은 수술 후 암 환자 결과와 관련 있음을 보여준다. 수술한 암환자의 의료의 질 향상과 환자 안전을 위해서는 적절한 간호사 수가 확보되어야 하며, 이를 위한 정책 유지가 필요하다.

• 한국정보과학회논문지:데이타베이스
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• 제41권4호
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• pp.256-261
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• 2014

Top-${\kappa}$ 유사도 조인 문제는 두 개의 입력 레코드 집합들에서 유사도를 기준한 상위 ${\kappa}$ 개의 레코드 쌍을 찾는 것이다. 샘플링 기법을 이용하여 상위 ${\kappa}$ 개의 유사도 조인 쌍을 반환하는 효율적인 알고리즘을 제안한다. 입력 레코드들의 표본에서 집합 유사도 조인들의 히스토그램을 구성하고, 상위 ${\kappa}$ 개의 조인 쌍을 위한 추정 유사도 한계치를 통계 추론으로 95% 신뢰 구간의 오차 한계 내에서 계산한다. 상위 ${\kappa}$ 개의 유사도 조인을 얻기 위하여 최소-히프 구조를 사용하는 일반 유사도 조인 알고리즘에 이 추정 한계치를 적용한다. 대 용량의 실제 데이터집합에서의 실험결과는 제안된 알고리즘의 좋은 성능을 보여준다.

• KIEAE Journal
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• 제13권3호
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• pp.15-20
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• 2013

The purpose of this study is to analyze the planning characteristics of passive house by the building structural types in foreign cases. The interests and demands about passive house have been increased, and various building structural types and design methods have been attempted for passive house in Korea. But domestic research results and development experiences about passive house were lack. The results of this study are as follows; First, in terms of energy performance, insulation performance, airtightness, there are not significant differences at the 95% confidence level by the structural types of passive house. Second, in terms of the types of insulation materials, there are significant differences at the 95% confidence level by the structural types of passive house. Third, in principle there is no need of traditional heating facility in passive houses, but in practice traditional heating facilities are used additionally in about half of survey cases for the comfort of occupants.

• Journal of Biosystems Engineering
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• 제24권6호
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• pp.539-546
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• 1999

오이를 공시재료로 하여, 생육중인 식물 잎으로부터 비교적 신속하게 생체정보 수집이 가능한 비파괴 계측기인 엽록소 측정기, 엽록소 형광측정기, 적외선 엽온측정기, 반사형 분광분석기를 이용하여 질소 결핍장해 오이의 조기 진단 가능성 여부와 그 유용한 정도를 파악하기 위하여 수행한 연구의 주요 결과는 다음과 같다. 1) 엽록소 측정기의 측정값으로서 질소 결핍장해 오이의 진단은 엽록소 함량 45 SPAD 이하 여부로서 판단할 수 있고, 이에 의한 질소 결핍 장해의 진단은 장해 발생 후 빠르면 3일 정도면 적중율 95%수준의 장해 진단이 가능하고 7∼10일 후엔 높은 정확도의 진단이 가능함을 알 수 있었다. 2) 엽록소 형광 측정에 의한 질소 결핍장해 오이의 진단은 장해 발생 후 빠르면 5일째부터 적중률 95%수준의 장해 진단이 가능하며, 이에 의한 오이의 질소 결핍장해 진단은 엽록소 함량 측정에 의한 진단보다는 우수하지 못하다. 그리고 대기-엽온차에 의해 질소 결핍장해 오이의 진단은 불가능한 것으로 판단되었다. 3) 분광분석기의 흡광도 분석에 의한 질소 결핍 진단의 민감 파장대는 562∼564 nm, 700∼724 nm, 1,886∼1,894 nm으로 분석되었다. 이러한 영역의 파장에 의한 질소 결핍장해 오이의 진단은 장해 발생후 3∼4일째부터 적중을 95%수준의 진단이 가능하며, 진단의 정확도는 본 연구에서 사용한 4가지 측정기 중 가장 우수하였다.

• 한국간호교육학회지
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• 제16권2호
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• pp.339-346
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• 2010

Purpose: Bystander cardiopulmonary resuscitation (CPR) improves survival. However, there have been few studies on the performance of bystander CPR in Korea. This study was done to identify the reasons for being unwilling to perform CPR, and to investigate the factors associated with performing CPR on a stranger in an emergency situation. Method: The participants in this study were 444 local residents. Data were collected by using self-reported questionnaires from May 1 to June 30, 2010. For data analysis, descriptive statistics and multiple logistic regression were performed using SAS version 9.1. Result: Only 32.2% of respondents reported being willing to perform CPR on a stranger. The major reason for not being willing to perform CPR on a stranger was "have no confidence to perform CPR well". From multiple logistic regression analysis, statistically significant predictors of CPR performance on a stranger were found to be a higher educational level (OR=6.11, 95% CI 1.46-25.52), neighbors with angina pectoris or myocardial infarction (OR=6.65, 95% CI 3.93-11.24), and having confidence of performing CPR (OR=3.02, 95% CI1.78-5.14). Conclusion: CPR education (including automatic external defibrillator) should be offered to family members and neighbors. In addition, the Good Samaritan Law must be given wider publicity at the national level.