• 대한수학회지
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• 제47권2호
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• pp.263-275
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• 2010

Let {$X_n;n\;\geq\;1$} be a strictly stationary sequence of negatively associated random variables with mean zero and finite variance. Set $S_n\;=\;{\sum}^n_{k=1}X_k$, $M_n\;=\;max_{k{\leq}n}|S_k|$, $n\;{\geq}\;1$. Suppose $\sigma^2\;=\;EX^2_1+2{\sum}^\infty_{k=2}EX_1X_k$ (0 < $\sigma$ < $\infty$). We prove that for any b > -1/2, if $E|X|^{2+\delta}$(0<$\delta$$\leq$1), then $$lim\limits_{\varepsilon\searrow0}\varepsilon^{2b+1}\sum^{\infty}_{n=1}\frac{(loglogn)^{b-1/2}}{n^{3/2}logn}E\{M_n-\sigma\varepsilon\sqrt{2nloglogn}\}_+=\frac{2^{-1/2-b}{\sigma}E|N|^{2(b+1)}}{(b+1)(2b+1)}\sum^{\infty}_{k=0}\frac{(-1)^k}{(2k+1)^{2(b+1)}}$$ and for any b > -1/2, $$lim\limits_{\varepsilon\nearrow\infty}\varepsilon^{-2(b+1)}\sum^{\infty}_{n=1}\frac{(loglogn)^b}{n^{3/2}logn}E\{\sigma\varepsilon\sqrt{\frac{\pi^2n}{8loglogn}}-M_n\}_+=\frac{\Gamma(b+1/2)}{\sqrt{2}(b+1)}\sum^{\infty}_{k=0}\frac{(-1)^k}{(2k+1)^{2b+2'}}$$, where $\Gamma(\cdot)$ is the Gamma function and N stands for the standard normal random variable.

• Korean Journal of Radiology
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• 제24권7호
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• pp.626-639
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• 2023

Objective: To investigate the association of clinical, pathologic, and magnetic resonance imaging (MRI) variables with progressive disease (PD) during neoadjuvant chemotherapy (NAC) and distant metastasis-free survival (DMFS) in patients with triple-negative breast cancer (TNBC). Materials and Methods: This single-center retrospective study included 252 women with TNBC who underwent NAC between 2010 and 2019. Clinical, pathologic, and treatment data were collected. Two radiologists analyzed the pre-NAC MRI. After random allocation to the development and validation sets in a 2:1 ratio, we developed models to predict PD and DMFS using logistic regression and Cox proportional hazard regression, respectively, and validated them. Results: Among the 252 patients (age, 48.3 ± 10.7 years; 168 in the development set; 84 in the validation set), PD was occurred in 17 patients and 9 patients in the development and validation sets, respectively. In the clinical-pathologic-MRI model, the metaplastic histology (odds ratio [OR], 8.0; P = 0.032), Ki-67 index (OR, 1.02; P = 0.044), and subcutaneous edema (OR, 30.6; P = 0.004) were independently associated with PD in the development set. The clinical-pathologic-MRI model showed a higher area under the receiver-operating characteristic curve (AUC) than the clinical-pathologic model (AUC: 0.69 vs. 0.54; P = 0.017) for predicting PD in the validation set. Distant metastases occurred in 49 patients and 18 patients in the development and validation sets, respectively. Residual disease in both the breast and lymph nodes (hazard ratio [HR], 6.0; P = 0.005) and the presence of lymphovascular invasion (HR, 3.3; P < 0.001) were independently associated with DMFS. The model consisting of these pathologic variables showed a Harrell's C-index of 0.86 in the validation set. Conclusion: The clinical-pathologic-MRI model, which considered subcutaneous edema observed using MRI, performed better than the clinical-pathologic model for predicting PD. However, MRI did not independently contribute to the prediction of DMFS.

• 대한교통학회지
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• 제32권4호
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• pp.369-379
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• 2014

전통적인 사고예측모형은 통계적 회귀분석에 주로 의존하였으나, 이는 자료 분포 및 함수 형태에 대한 가정에 따른 한계를 가지고 있다. 이에 따라 일부 연구는 신경망 등의 비모수적 기법을 모형 구축에 활용하였으나, 이는 독립변수와 종속변수 간의 직접적인 관계 규명이 어렵다는 한계가 있다. 유전자 프로그래밍 기법은 모형 개발에 특별한 가정이 필요없고, 사고요인 규명이 가능하다는 장점이 있다. 따라서 본 연구에서는 고속도로의 사고예측에 유전자 프로그래밍 기법을 적용함으로써 이러한 한계를 극복하고자 하였다. 이를 위하여 경부고속도로에서 최근 3년간(2010-2012년) 구득된 자료를 활용하였으며, 보다 세밀한 사고 특성 규명을 위해 고속도로 구간을 직선 구간과 곡선 구간으로 구분하였다. 사고 발생에 중요한 영향을 미치는 변수를 선택하기 위하여 랜덤 포레스트 기법을 이용하였으며, 최종 선택된 변수들을 활용하여 사고예측을 위한 유전자 프로그래밍 모형을 구축하였다. 구축된 모형의 예측 성능을 평가하기 위해 음이항 회귀모형과 비교해본 결과, 유전자 프로그래밍 모형의 예측 성능이 더 우수한 것으로 나타났다.

• 보건교육건강증진학회지
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• 제18권2호
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• pp.129-140
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• 2001

Harmful environment around school area have been increased with socio-economic development in Korea. Those entertainment facilities have caused a negative effect on the learning environment in many schools. As a result of increased entertainment harmful facilities in school area, the numbers of deviant behaviors such as drinking, smoking, substance abuse and sexual activity among junior high school students have been significantly increased. Given this situation, the aim of this study was to describe the distribution of the facilities; to access applied(experience) of the facilities according to students demographic variables; and to identify the relationship between use of the facilities and students risk health behaviors such as smoking, drinking, substance abuse and sexual activity. The field theory was used to study the relationship between the use of the facilities and risk health behaviors among students. A self-administered questionnaire survey was conducted in Korea. 2,114 junior and senior high school students(middle and high school students) were recruited by the method of proportional stratified random sampling from June to July 2000. Results indicated that: 1) The rates of using game centers, PC rooms, Song rooms and comic rooms were 78.3%, 75.6%, 71.6%, and 34.3% respectively. 2) High school students visited the entertainment facilities significantly more than middle school students(p〈0.001). 3) The rates of using facilities near schools were significantly associated with parents job(p〈0.05). 4) The rates of drinking, smoking, drug abuse, and sexual activity were 21.6%, 11.9%, 4.3% and 1.6% respectively. 5) Risk health behaviors such as smoking(p〈0.001) and drinking(p〈0.001), amount of smoking and drinking(p〈0.001) and sexual activity(p〈0.05) were associated with the experience of using the facilities. Those who had drinking experience were more likely to go the facilities than those without drinking experience. Also, those who were smoker had higher probability of going using the facilities than non-smokers.

• 한국안광학회지
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• 제18권3호
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• pp.321-327
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• 2013

목적: 수직주시시차의 유형별 분포를 분석하고 입체시와의 상관관계를 알아보고자 한다. 방법: 입체시 검사표는 부분적으로 random dot을 이용하는 RANDOT(R) stereotest를 사용하였다. 근거리에서 수직주시시차는 환자와의 거리를 25 cm 유지한 상태에서 Wesson fixation disparity card를 이용해, 한쪽 눈에 하나씩 보이는 두 개의 가는 선이 프리즘을 가입하여 한 줄로 일치될 때의 측정결과를 바탕으로 주시시차곡선을 6가지 유형으로 분류하였다. 결과: 43명을 대상으로 근거리 수직주시시차 곡선의 유형은 제 1유형이 55.82%로 가장 많이 분포하였고, 제 2유형이 23.25%로 가장 적게 분포하였으며, 제 3유형이 4.65%, 제 4유형은 4.65%, 제 5유형은 6.98%, 제 6유형은 4.65%로 분포하였다. 두 변수들 사이의 선형적 상관관계의 정도를 보는 상관분석의 결과를 보면 입체시는 수직주시시차를 나타내는 Y-intercept(r = -0.07), 일부융합제거시 사위량(r = -0.03), 완전융합제거시 사위량(r = -0.00)과 상관관계가 없는 것으로 나타났고, 통계적으로 유의하지 않았다(p>0.05). 수직주시시차 곡선의 기울기와는 r = 0.36으로 양의 상관관계를 가지며 그 관계는 낮은 편으로 통계적으로 유의하였다(p<0.05). 수직주시시차를 나타내는 Y-intercept는 일부융합 제거시 사위량(r = 0.89)과는 높은 상관관계를 보였으며 통계적으로 유의하였다(p<0.05). 수직주시시차 곡선의 기울기는 r = -0.33으로 음의 상관관계를 보였고, 그 관계는 낮았으며 통계적으로 유의하게 나타났다(p<0.05). 회귀분석(regresson analysis)결과, 입체시와 수직주시시차의 변화에 따른 관계는 수직주시시차가 1분( ' ) 변하면 입체시는 7.631초( ' ) 만큼 변화하며, 입체시가 1초( ' ) 변하면 수직주시시차는 0.017분( ' ) 만큼 변화하였고 통계적으로 유의하였다(p<0.05). 결론: 입체시와 수직주시시차는 낮은 상관관계를 보였으며, 수직주시시차 만으로 입체시를 판단하기 힘들며 입체시에 영향을 미치는 인자는 수직주시시차 이외의 다른 요인이 더 클 것으로 사료된다.

• 한국보건간호학회지
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• 제5권2호
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• pp.45-51
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• 1991

The purpose of this study is to investigate the stress and coping level as a result of dysmenorrhea which was experienced by girls. For the collection of data, the girls from the 1st to the 3rd grade in middle school in Seoul were selected through a random sampling technique. The survey was conducted from the 1st. to the 14th of June, 1991 by the use of questionnaires made after a pilot study. The final subjects for analysis were restricted to only those who had experienced me~arche, the number of which totaled 1,131. The stress, coping level, and other variables, were tested and analysed by descriptive statistics (eg, frequency, percentage, mean and standard deviation), t-test, ANOVA and Pearson's correlation coefficients. The obtained results are summarized as follows. 1. The chronological start for menarche was at a mean age of 13.1 The respondents who had experienced menarche numbered $70.9\%$ of the 1st grades and $96.2\%$ of the 2nd grades in middle school, otherwise the starting age for menarche was in the 4th grade in primary school. 2. Their menstrual cycle and period were longer than adult's one. The number of students studied who had experienced dysmenorrhea during their menstrual cycle were 860, and 650 of those revealed that their mothers or sisters had experienced similar problems. 3. The subjects who were late or head left early rather than being absent from school every menstruation cycle were more stressful. The results are thought to show that the girl's perception of dysmenorrhea seems to be more sensitive than adult's one. 4, A significant negative correlation was found between the perception of menstrual flow and strees level. It means that an increase in the stress of dysmenorrhea was associated with decreased menstrual bleeding. The degree of hypochondrical concern assessed by the girls was significantly correlated to stress and coping level. When the girls perceived high stress as a result of dysmenorrhea, they worried about their physical health more. The above results lead us to the suggestion that the starting point of early education with a school program is appropriate for the 4th grade in primary school. Especially if the girls in middle school should be required to give the information about correct knowledge and sufficient self -care management of menstruation monthly, if this could be implemented the loss in school days among the students due to dysmenorrhea would be minimized with more ease.