• Parasites, Hosts and Diseases
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• 제45권3호
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• pp.239-243
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• 2007

Many allergists are currently focusing on the development of new diagnostic tools, and are attempting to improve both the sensitivity and specificity. A multiple allergen simultaneous test-chemiluminescent assay (MAST-CLA) is one of the most popular diagnostic tools used in the Republic of Korea. However, there remains controversy among allergists with regard to the cut-off point for a positive result. The present study was conducted in order to determine the validity of MAST-CLA as compared with that of the skin prick test, with particular emphasis on arthropod allergens, on the basis of percentage agreement rates and k-values, and also to suggest the optimal positive cutoff points using receiver operating characteristic (ROC) curves. The study was conducted with 97 subjects (54 men, 43 women). Optimal individual cut-off points were calculated as follows; class II for Dermatophagoides farinae, class I for Dermatophagoides pteronyssinus, and trace for a cockroach mix. These findings suggest that attempting to apply optimal individual cut-off points will be a good way of improving diagnostic tests, particularly MAST-CLA.

• Asian Pacific Journal of Cancer Prevention
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• 제17권1호
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• pp.347-352
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• 2016

Background: This study used receiver operating characteristic curve to analyze Surveillance, Epidemiology and End Results (SEER) adenosquamous carcinoma data to identify predictive models and potential disparities in outcome. Materials and Methods: This study analyzed socio-economic, staging and treatment factors available in the SEER database for adenosquamous carcinoma. For the risk modeling, each factor was fitted by a generalized linear model to predict the cause specific survival. An area under the receiver operating characteristic curve (ROC) was computed. Similar strata were combined to construct the most parsimonious models. Results: A total of 20,712 patients diagnosed from 1973 to 2009 were included in this study. The mean follow up time (S.D.) was 54.2 (78.4) months. Some 2/3 of the patients were female. The mean (S.D.) age was 63 (13.8) years. SEER stage was the most predictive factor of outcome (ROC area of 0.71). 13.9% of the patients were un-staged and had risk of cause specific death of 61.3% that was higher than the 45.3% risk for the regional disease and lower than the 70.3% for metastatic disease. Sex, site, radiotherapy, and surgery had ROC areas of about 0.55-0.65. Rural residence and race contributed to socioeconomic disparity for treatment outcome. Radiotherapy was underused even with localized and regional stages when the intent was curative. This under use was most pronounced in older patients. Conclusions: Anatomic stage was predictive and useful in treatment selection. Under-staging may have contributed to poor outcome.

• 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.

• 대한안전경영과학회지
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• 제15권2호
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• pp.243-253
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• 2013

This research paper introduces the application and implementation of medical decision metrics that classifies medical decision-making into four different metrics using statistical diagnostic tools, such as confusion matrix, normal distribution, Bayesian prediction and Receiver Operating Curve(ROC). In this study, the metrics are developed based on cross-section study, cohort study and case-control study done by systematic literature review and reformulated the structure of type I error, type II error, confidence level and power of detection. The study proposed implementation strategies for 10 quality improvement activities via 14 medical decision metrics which consider specificity and sensitivity in terms of ${\alpha}$ and ${\beta}$. Examples of ROC implication are depicted in this paper with a useful guidelines to implement a continuous quality improvement, not only in a variable acceptance sampling in Quality Control(QC) but also in a supplier grading score chart in Supplier Chain Management(SCM) quality. This research paper is the first to apply and implement medical decision-making tools as quality improvement activities. These proposed models will help quality practitioners to enhance the process and product quality level.

• 치과방사선
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• 제29권1호
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• pp.65-85
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• 1999

Objectives: To determine the effect of interpolation functions when processing the digital periapical images. Material and Methods: The digital images were obtained by Digora and CDR system on the dry skull and human subject. 3 oral radiologists evaluated the 3 portions of each processed image using 7 interpolation methods, and ROC curves were obtained by trapezoidal methods. Results: The heighest Az value(0.96) was obtained with cubic spline method and the lowest Az value(0.03) was obtained with facet model method in Digora system. The heighest Az value (0.79) was obtained with gray segment expansion method and the lowest Az value(0.07) was obtained with facet model method in CDR system. There was significant difference of Az value in original image between Digora and CDR system at a=0.05 level. There were significant differences of Az values between Digora and CDR images with cubic spline method, facet model method, linear interpolation method and non-linear interpolation method at α=0.1 level.

• 한국방사선학회논문지
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• 제10권6호
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• pp.443-450
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• 2016

본 연구는 복부 전산화단층촬영 영상을 이용하여 지방간환자의 영상을 질감특징분석과 ROC curve 분석을 하였으며, 컴퓨터보조진단시스템의 구현을 위한 실험적인 선형 연구로서 전산화단층촬영 영상에서 지방간의 객관적이고 신뢰성 있는 진단 정보를 의사에게 제공하고자 하였다. 실험은 정상 및 지방간 복부 전산화단층촬영 영상을 실험영상으로 하여 설정된 구역에 대한 wavelet 변환을 거쳐 질감의 특징값을 나타내는 6가지 파라미터로 통계적 분석 결과를 나타내었다. 그 결과 엔트로피, 평균밝기, 왜곡도는 90% 이상의 비교적 높은 인식률을 보였고, 대조도, 평탄도, 균일도는 약 70% 정도로 비교적 낮은 인식률을 나타내었다. ROC curve를 이용한 분석에서 6가지의 파라미터 모두 0.900(p=0.0001)이상을 나타내어 질환인식에 의미가 있는 결과를 나타내었다. 또한 6가지 파라미터에서 질환 예측을 위한 cut-off 값을 결정하였다. 이러한 결과는 향후 복부 전산화단층촬영 영상에서 질환 자동검출 및 최종진단의 예비 진단 자료로서 적용 가능할 것이다.

• Clinical and Experimental Reproductive Medicine
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• 제36권4호
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• pp.255-263
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• 2009

목 적: 한국 가임기 여성의 다낭난소증후군 진단시에 복식 초음파를 이용하는 방법의 유용성과 정확도를 분석하여 국내 다낭난소증후군의 진단 기준 마련에 도움이 되고자 하였다. 연구방법: 이화여자대학교 목동병원에서 선별설문조사를 받은 15~44세 여성 8,793명에서 복식 초음파를 시행한 총 701명 중, 정상 월경을 하면서 안드로겐 과다 및 초음파의 다낭난소 소견이 없는 정상 대조군에서 복식 초음파를 시행한 185명과 초음파 검사 소견을 제외하고 NIH 진단 기준으로 다낭난소증후군을 진단 받은 248명의 환자에서 복식 초음파를 시행한 소견을 ROC (receiver operating characteristic) 곡선 분석하였다. 결 과: 정상 대조군의 평균 연령은 $23.64{\pm}4.26$세로 복식 초음파로 측정된 평균 난소 부피는 $6.03{\pm}1.89\;cm^3$, 평균 난포 개수는 $6.49{\pm}1.93$개였다. 복식 초음파를 진단에 사용할 경우 난소 부피를 이용하면 AURC (area under the ROC curve)가 0.761로 난소 부피>$9\;cm^3$ 기준일 때, 민감도 51.0%, 특이도 91.4%였다. 난포 개수에 대한 AURC는 0.733으로 ${\geq}9$개 기준일 때, 민감도 54.9%, 특이도 87.0%였으며, 난포 개수 ${\geq}10$개 기준일 때, 민감도 53.2%, 특이도 90.4%였다. 복식 초음파로 난소 부피와 난포 개수를 검사하여 다낭난소증후군의 선별 진단에 이용하기에는 부적합하였다. 결 론: 복식 초음파를 이용하여 다낭난소증후군을 진단하는 방법은 유용성과 정확도에서 신뢰할만하지 못하다.

• 한국콘텐츠학회논문지
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• 제10권7호
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• pp.107-114
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• 2010

색채는 빛을 통해 인간이 시각적으로 느끼는 감각으로, 사람이 인지할 수 있는 색채인 유채색(chromatic color area)과 무채색(achromatic color area)으로 구분할 수 있다. 유채색은 색상, 명도, 채도의 속성이 존재하지만 무채색은 유채색의 속성 중 명도는 있지만 색상과 채도의 성격을 갖지 않는다. 따라서 인간의 시각에 기초하여 인간이 색채를 인지할 수 있는 영역과 인지하지 못하는 영역을 분리하는 것은 중요하다. 본 논문에서는 영상의 유채영역인 색상영역과 무채영역인 비색상영역을 분리하는 함수를 도출한다. 먼저 입력된 RGB 컬러공간의 입력영상을 인간의 시각을 고려한 HSI 컬러공간으로 변환하여 이진영상을 구한 후 색상 영역(ROC: Region of chromatic)과 비색상 영역(ROA:Region of achromatic)으로 분류하기 위한 함수를 도출한다. 일반영상에서 ROC와 ROA의 영역을 분리하기는 어려우므로 색상영역과 비색상영역을 도출하기 위해 색상값의 변화가 크지 않고 명암과 채도가 변화하는 그레디언트 영상을 생성하여 함수를 도출한다. 성능평가는 실험영상과 일반영상의 결과영상을 비숙련가 50인에게 주관적 화질평가를 실시하였으며 제안방법은 기존의 방법에 비해 27.5~32.96%가 개선되었다.

• 한국콘텐츠학회논문지
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• 제13권12호
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• pp.829-839
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• 2013

본 연구는 로지스틱 회귀분석과 의사결정나무 분석을 활용하여 일 대도시 주민의 우울에 영향을 주는 요인을 예측하고 비교하고자 시도된 서술적 조사연구이다. 연구대상은 20세에서 65세 미만의 일 대도시 주민 462명이었다. 자료 수집은 2011년 10월 7일부터 10월 21일까지이었으며, 자료 분석은 SPSS 18.0 프로그램을 이용하여 빈도, 백분율, 평균과 표준편차 및 ${\chi}^2$-test, t-test, 로지스틱 회귀분석, roc curve, 의사결정나무 분석으로 분석하였다. 본 연구 결과, 로지스틱 회귀분석과 의사결정나무 분석에서 공통적으로 나타난 우울 예측요인은 사회부적응, 주관적 신체증상 및 가족 지지이었다. 로지스틱 회귀분석에서 특이도 93.8%, 민감도 42.5%이었고, 본 연구의 모형 적합도를 roc curve 검증 한 결과 AUC=.84으로 본 연구 모형은 적합(p=<.001)하다고 할 수 있다. 우울예측에 대한 의사결정나무 분석은 분류에 대한 예측 정확도에서 특이도 98.3%, 민감도 20.8%이었고, 전체 분류 정확도는 로지스틱 회귀분석은 82.0%, 의사결정나무 분석은 80.5% 이었다. 본 연구 결과 민감성과 분류 정확도와 더 높게 나타난 로지스틱 회귀분석 방법이 지역 주민의 우울 예측 모형을 구축하는데 더 유용한 자료로 사용될 수 있으리라 사료된다.

• 한국도로학회논문집
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• 제20권2호
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• pp.35-44
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• 2018

PURPOSES : The purpose of this research is to analyze the characteristics of panels that affect the evaluating results of riding quality and to evaluate the appropriateness of roughness management criteria based on ride comfort satisfaction. METHODS : In order to analyze the influence of panel characteristics of riding quality, 33 panels, consisting of civilians and experts, were selected. Also, considering the roughness distribution of the expressway, 35 sections with MRI ranging from 1.17 m/km to 4.65 m/km were selected. Each panel boarded a passenger car and evaluated the riding quality with grades from 0 to 10, and assessed whether it was satisfied or not. After removing outlier results using a box plot technique, 964 results were analyzed. An ANOVA was conducted to evaluate the effects of panel expertise, age, driving experience, vehicle ownership, and gender on the evaluation results. In addition, by using the receiver operating characteristics (ROC) curve, the MRI value, which can most accurately evaluate the satisfaction with riding quality, was derived. Then, the compatibility of MRI was evaluated using AUC as a criterion to assess whether the riding quality was satisfactory. RESULTS : Only the age of the panel participants were found to have an effect on the riding quality satisfaction. It was found that satisfaction with riding quality and MRI are strongly correlated. The satisfaction rate of roughness management criteria on new (MRI 1.6 m/km) and maintenance (MRI 3.0 m/km) expressways were 95% and 53%, respectively. As a result of evaluating the roughness management criteria by using the ROC curve, it was found that the accuracy of satisfaction was the highest at MRI 3.1-3.2 m/km. In addition, the AUC of the MRI was about 0.8, indicating that the MRI was an appropriate index for evaluating the riding quality satisfaction. CONCLUSIONS : Based on the results, the distribution of the panels' age should be considered when panel rating is conducted. From the results of the ROC curve, MRI of 3.0 m/km, which is a criterion of roughness management on maintenance expressways, is considered as appropriate.