• Asian Pacific Journal of Cancer Prevention
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• 제14권5호
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• pp.3219-3221
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• 2013

Background: This study used receiver operating characteristic (ROC) curves to screen Surveillance, Epidemiology and End Results (SEER) skin melanoma data to identify and quantify the effects of socioeconomic factors on cause specific survival. Methods: 'SEER cause-specific death classification' used as the outcome variable. The area under the ROC curve was to select best pretreatment predictors for further multivariate analysis with socioeconomic factors. Race and other socioeconomic factors including rural-urban residence, county level % college graduate and county level family income were used as predictors. Univariate and multivariate analyses were performed to identify and quantify the independent socioeconomic predictors. Results: This study included 49,999 parients. The mean follow up time (SD) was 59.4 (17.1) months. SEER staging (ROC area of 0.08) was the most predictive foctor. Race, lower county family income, rural residence, and lower county education attainment were significant univariates, but rural residence was not significant under multivariate analysis. Living in poor neighborhoods was associated with a 2-4% disadvantage in actuarial cause specific survival. Conclusions: Racial and socioeconomic factors have a significant impact on the survival of melanoma patients. This generates the hypothesis that ensuring access to cancer care may eliminate these outcome disparities.

• 한국수자원학회논문집
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• 제36권5호
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• pp.879-892
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• 2003

본 연구에서는 강우의 지역빈도분석에 필요한 수문학적 동질성을 갖는 지점강우의 권역화를 수행하였다. 이를 위해 전국에 걸친 기상청 산하의 60개 강우관측소에 대한 32개의 강우특성자료를 추출하였으며, 추출된 각 지점의 많은 강우자료들은 다변량 분석의 자료축약기법인 주성분분석과 그룹화 기법인 군집분석을 통하여 합리적이고 효율적으로 권역화되었다. 본 연구의 결과인 지점강우의 권역은 강우지역을 수문학적 동질성의 5개 권역과 3개의 기타지역으로 분류되었으며, 각 강우성분의 권역별 평균값으로부터 각 권역의 강우특성을 상대적으로 비교 분석하였다.

• 간호행정학회지
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• 제21권2호
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• pp.184-192
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• 2015

Purpose: This study was done to assess nursing students' practice of patient safety management (PSM), identify factors affecting PSM and provide basic data to develop education programs to strengthen students' competencies for patient safety. Methods: In this descriptive research the practice of PSM by nursing students was examined and predictive factors were identified. Participants were junior and senior nursing students from 7 universities in 7 cities. Self-report questionnaires were used for data collection. Results: Significant positive correlations were found between knowledge of PSM, perception of the importance of PSM and practice of PSM. In multivariate analysis, women students, participation in patient safety education in school, knowledge of PSM, and practice of PSM predicted high perception of the importance of PSM. In multivariate analysis, senior year and participation in patient safety education in school predicted higher knowledge of PSM. In multivariate analysis, perception of the importance of PSM predicted high practice of PSM. Conclusion: In this study, knowledge was not found to directly affect PSM practice, but was found to affect the perception of the importance of PSM, a significant predictive variable. Thus, the importance of PSM should be strongly emphasized during education.

• 경영과학
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• 제32권2호
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• pp.69-78
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• 2015

This paper considers a Bayesian Poisson model for multivariate count data using multiplicative rates. More specifically we compose the parameter for overall arrival rates by the product of two parameters, a common effect and an individual effect. The common effect is composed of autoregressive evolution of the parameter, which allows for analysis on seasonal effects on all multivariate time series. In addition, analysis on individual effects allows the researcher to differentiate the time series by whatevercharacterization of their choice. This type of model allows the researcher to specifically analyze two different forms of effects separately and produce a more robust result. We illustrate a simple MCMC generation combined with a Gibbs sampler step in estimating the posterior joint distribution of all parameters in the model. On the whole, the model presented in this study is an intuitive model which may handle complicated problems, and we highlight the properties and possible applications of the model with an example, analyzing real time series data involving customer arrivals to a large retail store.

• Journal of the Korean Data and Information Science Society
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• 제16권2호
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• pp.349-357
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• 2005

Principal component analysis(PCA) was carried out to evaluate the water quality with the monitering data collected from 1997 to 2003 along the coastal area of Ulsan, Korea. To enhance evaluation and to complement descriptive power of traditional PCA, optimal scaling was applied to transform the original data into optimally scaled data. Cluster analysis was also applied to classify the monitering stations according to their characteristics of water quality.

• 지구물리와물리탐사
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• 제1권3호
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• pp.170-175
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• 1998

이 연구는 다변량 통계 기법을 이용한 물리검층 자료로부터의 암석물리학상 결정으로 암상을 예측하는 것이다. 기술 통계 분석으로 물리검층 자료의 특성을 파악하고 주성분 분석에 의한 다변량 검층 자료들의 상관도 분석을 통해 변수들을 변환시켜 새로운 변수인 주성분을 구하고 변수들의 차원을 축소한다. 통계적 방법에 의한 주성분 검층 자료의 구획에 의한 효율적 자료 축소와 계산의 효율성을 높여 양질의 해석결과를 얻을 수 있다. 구획된 주성분 검층 자료로부터 계보적 군집 분석에 의해 암석물리학상을 결정한다. 최적 암석물리학상의 수는 전체 변동과 군집내의 변동사이의 비와 코어자료 등에 의해 비교 결정된다. 이 연구에서 개발된 암석물리학상 결정법을 국내대륙붕 물리검층자료에 적용한 결과 결정된 암석물리학상은 시추 코어 및 시추 암편 분석에 의한 암상 구분화와 잘 일치하였다. 이러한 연구는 저류층 특성인자의 신뢰성 있고 정량적인 평가로 유전 개발 및 생산 계획 시 유용한 도구로 활용될 수 있을 것이다.

• 한국품질경영학회:학술대회논문집
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• 한국품질경영학회 1998년도 The 12th Asia Quality Management Symposium* Total Quality Management for Restoring Competitiveness
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• pp.295-300
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• 1998

Recently graphical modelling is being studied as a useful process analysis tool for exploratory causal analysis. Graphical modelling is a presentation method that uses graphs to describe statistical models of the structures of multivariate data. This paper describes an application of this graphical modeling with two cases from the automotive parts industry. One case is the unbalance problem of the pulley, an automotive generator part. There is multivariate data of the product from each of the processes which are connected in the series. By means of exploratory causal analysis between the variables using graphical modeling, the key processes which causes the variation of the final characteristics and their mechanism of the causal relationship have become clear. Another case is, also, the unbalanced problem of automotive starter parts which consists of many parts and is manufactured by complex machinery and assembling process. By means of the similar technique, the key processes are obtained easily and the results are reasonable from technical knowledge.

• 응용통계연구
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• 제5권1호
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• pp.103-111
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• 1992

다변량 통계분석기법중 하나로 제기된 투사지향방법은 다변량자료를 관심있는 일차원 또는 이차원의 자료로의 선형투사를 찾아 나가는 방법이다. 이 방법은 다변량 자료가 갖는 차원의 문제를 해결해 줄 수 있는 유용한 기법으로 제시되었다. 본 연구에서는 투사지향방법을 이용하여 추정한 다변량 확률밀도함수를 사용한 새로운 비모수적인 판별분석방법을 제시하고, 이를 기존의 모수적 판별분석방법중 실제적으로 많이 사용되는 선형판별함수방법, 그리고 기존의 비모수적 판별분석방법중 계산상의 편리성이 많은 K-최인접방법과 컴퓨터 시뮬레이션을 통하여 비교분석하였다.

• International Journal of Automotive Technology
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• 제4권2호
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• pp.101-108
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• 2003

There are a lot of factors that influence automotive fuel economy such as average trip time per kilometer, average trip speed, the number of times of vehicle stationary, and so forth. These factors depend on road conditions and traffic environment. In this study, various driving data were measured and recorded during road tests in Seoul. The accumulated road test mileage is around 1,300 kilometers. The objective of the study is to identify the driving patterns of the Seoul metropolitan area and to analyze the fuel economy based on these driving patterns. The driving data which was acquired through road tests was analysed statistically in order to obtain the driving characteristics via modal analysis, speed analysis, and speed-acceleration analysis. Moreover, the driving data was analyzed by multivariate statistical techniques including correlation analysis, principal component analysis, and multiple linear regression analysis in order to obtain the relationships between influencing factors on fuel economy. The analyzed results show that the average speed is around 29.2 km/h, and the average fuel economy is 10.23 km/L. The vehicle speed of the Seoul metropolitan area is slower, and the stop-and-go operation is more frequent than FTP-75 test mode which is used for emission and fuel economy tests. The average trip time per kilometer is one of the most important factors in fuel consumption, and the increase of the average speed is desirable for reducing emissions and fuel consumption.

• 한국습지학회지
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• 제21권4호
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• pp.281-289
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• 2019

본 연구에서는 남부 내륙지역에 속한 시군구별 태풍으로 인한 피해를 예측할 수 있는 태풍피해예측모형을 개발하였다. 내륙지역의 태풍 피해는 호우, 강풍으로 인한 피해가 복합적으로 발생하므로, 모형을 구성하는 변수가 많고 다양하나, 내륙지역 시군구 단위의 피해사례는 모형을 개발할 만큼 충분하지 않다. 태풍피해 관련 수문기상 자료는 3시간 간격 지속기간별 최대 강우량, 총강우량, 1-5일 선행강우량, 최대풍속 및 제주도 인근 지역에서의 태풍중심기압을 이용하였다. 피해자료의 부족을 고려하기 위해 군집화를 하였으며, 강우 관련 자료의 다중공선성을 제거하기 위하여 주성분분석 등 다변량 통계분석을 이용하여 권역별(경남, 경북, 전남, 전북)로 피해예측모형을 개발하였다. 모형에 의한 태풍피해추정치와 실측치는 최대 2.2배 정도까지 차이가 발생하였는데, 이는 강풍에 의한 피해를 추정하기 어렵고, 전국 69개 ASOS 관측소에 의한 강우자료가 지역적 강우특성을 제대로 반영하지 못하기 때문인 것으로 추정된다.