• Journal of the Korean Statistical Society
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• 제28권2호
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• pp.195-210
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• 1999

We consider a large class of exponential regression models with censored data and propose two modified Fisher scoring methods with corresponding algorithms. These proposed methods improve the Newton-Raphson method in estimating the model parameters. The simulated and real examples are illustrated in aspect of convergence.

• 한국산업정보학회논문지
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• 제4권2호
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• pp.39-43
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• 1999

임의중도절단자료(randomly censored data)를 갖는 일반화된 지수회귀모헝을 고려하여 이 모형에서 모수를 추정하는 수정된 피선 점수화(modified Fisher scoring)방법을 제안한다. 이를 위해 우도방정식(likelihood equations)이 유도되고 추정알고리즘(estimating algorithm)이 개발된다. 실제의 자료를 통해 제안된 방법을 예증한다.

• Restorative Dentistry and Endodontics
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• 제30권1호
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• pp.31-37
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• 2005

본 실험은 resin 시편을 이용하여 미리 제작한 근관 내 불규칙 확장부에서 근관 충전용 sealer의 적용 방법에 따른 충전 효과를 평가해 보았다. Endo-training Bloc을 절단하여 사십 개의 규격화된 resin 블록 시편을 획득하였다. 각각의 시편에 $\#20$, 08taper GT 파일을 사용하여 근관을 형성하였고 근관에 손상이 가지 않도록 시편을 양분한 후 양분된 시편의 한 쪽 근관 벽에 다양한 근관 내 확장부를 표현하는 구를 형성하였다. 양분된 시편을 결찰하고 절단 부위를 밀봉하였으며 AH26 sealer를 사용하여 단일 cone 충전법으로 근관을 충전하였다. 네 가지의 근관 충전용 sealer의 적용방법을 이용하였다: A군, $\#20$ K-file : B군, ultrasonic file : C군, lentulo spiral: D군. EZ-Fill bi-directioanl spiral. 모든 시편은 $37^{\circ}\;100\%$ 상대습도에서 1주일간 보관한 후 각 시편을 근단에서 3mm, 4mm, 5mm 부위에서 수평으로 절단하고 각각의 절단면을 위상차현미경과 디지털 카메라를 이용하여 30배율로 관찰하고 촬영하였다. 관찰된 절단면은 scoring system을 이용하여 점수를 산정하였고 각 군 간의 통계적인 유의성 유무는 Fisher's Exact Test를 이용하여 시행하였다.

• Journal of Trauma and Injury
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• 제24권2호
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• pp.89-94
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• 2011

Purpose: A few studies have assessed the factors affecting the prognoses for major trauma patients and those improving the circumstances when dealing with the trauma system. In that light, we analyzed factors, such as pre-hospital factors, the time to admission, the length of stay in the emergency department (ED) and emergency operation, influencing the outcomes for trauma patients. Methods: The patients who visited our emergency department from April 1, 2009, to February 29, 2011, due to major trauma were enrolled in the study. The inclusion criterion was a revised trauma score (RTS) < 7 or injury severity score (ISS) ${\geq}$ 16. We used reviews of medical records, to analyze each step of emergency medical care with respect to patients' sex, age, visit time and visit date. Continuous variables were described as a median with an interquartile range, and we compared the variables between the survival and the mortality groups by using the Mann-Whitney U test. Fisher's exact test was used for nominal variables. Using the variables that showed statistical significance in univariate comparisons, we performed a logistic regression analysis, and we tested the model's adequacy by the using the Hosmer-Lemeshow method. Results: A total of 261 patients with major trauma satisfied either the RTS score criterion or the ISS score criterion. Excluding 12 patients with missing data, 249 patients were included in this study. The overall mortality rate was 16.9%. Time to ED arrival, time to admission, time of ED stay, RTS, ISS, and visit date being a holiday showed statistically significant differences between the survival and the mortality groups in the univariate analysis. RTS, ISS, length of ED stay, and visit date being a holiday showed statistical significance in the multivariate analysis. Conclusion: The mortality rate did not show a significant relationship with the time to ED arrival, use of 119, on time to admission. Rather, it elicited a quite significant correlation with the trauma scoring system (RTS and ISS), the time of ED stay, and the visit date being a holiday.