• Journal of Nutrition and Health
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• 제38권7호
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• pp.578-585
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• 2005

Maternal zinc deficiency is relatively common worldwide, but its consequences for pregnancy outcome are not established. The purpose of this study was to examine the effect of zinc status in the second trimester on pregnancy outcome. Subjects were 248 pregnant Korean women (25-28 wk gestation). Cord blood was collected from subgroup of 69 women and pregnancy outcome data were obtained from 185 babies. Anthropometry measurement, dietary intake, and biochemical characteristics of pregnancy and cord serum substances were measured. The subjects were divided into quartiles on the basis of maternal serum Zn concentration; $ZnQ_1$ (< 25 percentile), $ZnQ_2$ ($26\~50$ percentile), $ZnQ_3$ ($51\~75$ percentile), and $ZnQ_4$ ($76\~100$ percentile). Zn groups were compared in terms of various maternal factors, concentrations of cord serum substances, and pregnancy outcome. Maternal serum Zn concentration was $118.4\;{\pm}\;35.5\;{\mu}g/dl$ as mean. Intake of Zn was lower than Korean RDA. The rate of Zn deficiency among all subjects was $8.5\%$. Maternal serum Zn levels belonged to normal range. Cord serum Zn level was about $154.7\%$ of maternal serum level. Intakes of energy, calcium, iron, folic acid, and riboflavin did not meet the Korean RDA for pregnant women by gestational age. The mean birth weight of neonates is 3083 $\pm$ 697 g, of whom $9.1\%$ were of low birth weight (< 2,500 g). Maternal serum Zn level was positively correlated with pre-pregnancy weight, pre-pregnancy body mass index, and vitamin C intake (p < 0.05). $ZnQ_1$ group had significantly lower maternal serum iron concentration and higher cord serum cholesterol than those in other groups. Maternal serum Zn level, cord serum Zn level, and dietary Zn intake were no related to the pregnancy outcome. The birth weight had a correlation with the maternal hemoglobin and albumin concentration. In conclusion, at this study, we could not find the association with maternal Zn status in 2nd trimester and pregnancy outcome.

• 대한한방소아과학회지
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• 제36권3호
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• pp.49-62
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• 2022

Objectives This study aimed to provide evidence for the use of Korean medicine in underweight patients by analyzing the medical records of underweight children and adolescents. Methods Children and adolescents who visited Korean pediatrics at Kyung Hee University Hospital from June 1, 2019 to May 31, 2022, who had an age-specific weight percentile which was less than 5 and diagnosed with E639.005 or R628.001 were selected for the study. A retrospective chart review was conducted by examining the medical records of subjects who received Korean medical treatment. The treatment effect was analyzed in all subjects and subgroups by comparing changes in height, weight, and body mass index (BMI) percentiles before and after Korean medicine treatment. Results A total of 55 underweight subjects were included in the study. General characteristics such as distribution by sex, age, number of visits, and weight percentile, and clinical characteristics such as diagnosis, past history, family history, drug history, current or past symptoms, and symptom differentiation were collected. The composition of herbal medicines and the contents of other Korean medical treatments were analyzed. In the case of treatment effect, the weight and BMI percentile of all subjects increased significantly. Conclusions This study was conducted to suggest Korean medicine as a method of proper weight management in children and adolescents. In the future, follow-up studies with a large number of subjects and controlled variables, such as the period of taking herbal medicine, are needed.

• 대한토목학회논문집
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• 제30권2D호
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• pp.105-111
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• 2010

주행속도는 고속도로 설계와 운영에 있어 주요한 요소 중 하나이다. 거시적으로 자유교통류 속도(FFS)를 분석한 몇 몇 연구가 보고되고 있으나, 표본수가 적고 교통량과 일중 시간대의 영향을 고려하지 않았다. 본 연구는 FFS의 특성을 분석하기 위해 방대한 양의 표본을 이용하여 자유교통류 상태에서 교통량 수준별 일중 시간대별에 따른 FFS의 분포와 Percentile속도를 미시적으로 분석하였다. 분석결과, 속도분포는 교통량(1-5대/30초)과 일중 시간대(0-5, 6-8, 9-11, 12-19, 20-23)에 따라 변화하였으며 다른 행태를 보였다. 아침, 저녁, 심야 시간대의 V85(85th Percentile 속도)는 교통량이 증가함에 따라 감소하였지만, 오전과 오후 시간대의 V85는 큰 변화를 보이지 않았다. 따라서 시간대에 따른 V85는 교통량이 증가함에 따라 급격하게 변화하였다.

• 한국식생활문화학회지
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• 제25권2호
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• pp.170-178
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• 2010

We conducted this study to determine the factors associated with childhood obesity. The subjects were 170 preschool children in Busan. Data were collected by using questionnaires which asked for information about socioeconomic status, parental perception of their child's weight status and dietary/physical activity behavior. BMI was calculated for each child and their classification was determined, according to their age and sex, as follows: "overweight" at or above the 85th percentile, "normal" for the 15th-85th percentile, and with a BMI below the 15th percentile the children were deemed as underweight. Classification according to BMI percentile showed that 23.5% ($18.25{\pm}1.33\;kg/m^2$) of the children were overweight, 62.9% ($15.51{\pm}0.76\;kg/m^2$) normal, and 13.5% ($13.23{\pm}2.86\;kg/m^2$) were underweight. Socioeconomic status, as represented by the parents' level of education, the occupation of the father and the household income, did not affect the results. However, mothers working outside the household was a factor that was more likely to affect the weight status (p<0.05). Among mothers whose children were overweight, 30% underestimated their children's weight status (believing them to be of normal weight when they were overweight), and 25% failed to recognize the necessity of weight control for their overweight children. While sedentary activity and total daily activity levels were not related to BMI, the level of physically active leisure activity was inversely correlated with BMI (p<0.05). Although there were no differences in total energy intake, dietary behavior was significantly related to weight status. Overweight children had poor eating tendancies: they eat faster (in less than 15 minutes), overeat, and eat late at night. Based on our findings where hereby recommended the following interventions to help limit weight problems in Korean pre-schoolers: early promotion of active leisure behavior and healthy eating habits, along with attempting to correct parental misperception of healthy weight status for children.

• 응용통계연구
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• 제37권2호
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• pp.177-189
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• 2024

관리도에서 런길이는 관리 통계량이 관리한계를 벗어날 때까지 관측한 표본의 수로 정의한다. 일반적으로 런길이의 분포는 비대칭이 심하고 변동성이 크기 때문에 평균 런길이만 사용하여 관리도를 설계하고 성능을 평가하는 것은 적절하지 않을 수도 있다. 평균 런길이 기반 설계에 대한 대안으로 이 논문에서는 백분위수를 기반으로 한 관리도의 설계를 소개하고, 이를 지수가중이동평균 관리도의 설계에 적용하는 절차를 제안하고 있다. 이 절차는 백분위수 모수들이 주어진 경우, 모의실험을 통하여 적합된 함수를 사용하여 관리한계의 계수를 설정하는 것이다. 또한 모의실험을 수행하여 제안된 설계 절차를 평균 런길이 기반 설계와 비교하고 평가하였다. 모의실험 결과, 제안된 절차는 이상상태에서 탐지 능력은 거의 유지하면서 관리상태에서의 성능을 향상시킨다는 사실을 확인할 수 있었다.

• 자원ㆍ환경경제연구
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• 제13권1호
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• pp.49-82
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• 2004

울산 지역에서 대기중 벤젠으로 인한 발암 인체영향에 대한 경제성 평가를 위해서, 건강 위해성 평가를 수행하여 대상 지역의 이론적 암 사망자수를 추정하고, 대상 지역 주민을 대상으로 가상 가치평가법을 통한 위해도 감소의 지불의사금액을 추정하여 1인의 통계적 생명가치액을 유도하여 이론적 암 사망자수에 대한 사망 손실비용을 유도하였다. 대상 지역의 대기중 벤젠의 평균 농도는 $7.88{\mu}g/m^3$(min: 1.16~max: $23.32 {\mu}g/m^3$)로 조사되었다. US EPA IRIS의 벤젠 단위 위해도 $2.2{\times}10^{-6}{\sim}7.8{\times}10^{-6}$을 사용하고, 30세 이상의 노출인구수 51만 6,641명에 대한 연간 인구 집단 위해도를 추정한 결과 10년간 발생 가능한 발암 사망자수는 2.90명(5 percentile: 0.32명~95 percentile: 9.11명)으로 조사되었다. 1인의 통계적 생명가치액을 추정하기 위하여, 공단 지역의 지불의사금액 모형을 추정한 결과, 응답자의 암 치료경험 유 무와 기대 여명, 가족수, 교육수준이 유의한 영향 요인으로 조사되었고, 연간 1만 명당 5명의 위해도 감소에 대한 지불의사금액은 월 1만 4,852원(95% C.I: 1만 3,135원~1만 6,794)으로 산출되었으며, 위해도 감소치를 고려한 1인의 통계적 생명가치액은 약 3억 6,000만 원(95% C.I: 3억 2,000만 원~4억 원)으로 추정되었다. 대기중 벤젠의 발암 영향으로 인한 건강 손실비용은 발암 위해성 평가로 추정된 이론적 사망자수에 1인의 통계적 생명가치액을 곱하여 추정하였다. 추정 결과, 현 수준의 벤젠의 발암 영향이 10년간 지속될 경우 약 10억 원(5 percentile: 1억 원~95 percentile: 33억 원)의 건강 손실이 있는 것으로 추정되었다. 본 연구 결과, 대기중 벤젠의 노출로 인한 위해도를 줄이기 위해서는 벤젠 단독물질에 대해서 이론적으로 10년간 약 10억 원에 대응하는 감소 대책에 투자하여야 한다. 그러나 벤젠 한 물질만을 감소시키기 위한 대안은 현실적이지 못하므로, 이 연구를 모델로 하여 차후 벤젠을 포함한 휘발성 유기오염물질에 대한 통합 적용이 필요하고 손실비용을 재추정해야 할 것이다.

• 한국수자원학회논문집
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• 제56권2호
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• pp.115-124
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• 2023

현재 극한기상의 발생빈도가 많아지면서 극한기상현상이 발생하였을 때 피해규모는 증가하고 있다. 이게 과거부터 강우량의 예측을 위해 많은 시간과 제원을 투자하여 예측정보를 제공하고 있다. 하지만 이러한 정보는 전문가가 아닌 일반인이 이해하기 어려우며 특히 극한기상현상이 발생하였을 때 어느정도의 규모의 피해가 발생하는지에 대한 정보는 포함되어 있지 않다. 이에 본 연구에서는 영국에서 최초로 제시한 Risk Matrix 작성을 통해 영향예보 기준을 활용하여 호우피해 등급기준 Risk Matrix를 제시하였다. 먼저 강우량 자료와 피해자료와의 상관 분석을 통해 Risk Matrix 작성에 필요한 변수를 선정하고 선행연구에서 제시된 PERCENTILE (25%, 75%, 90%, 95%)과 JNBC(Jenks Natural Breaks Classification)기법을 이용하여 강우량과 피해에 따른 등급기준을 산정하여 두 개의 등급기준을 합성하여 하나의 기준을 제시하였다. 분석 결과에 이재민 세대수 결과의 경우 가장 많은 피해가 발생하였던 영산강, 섬진강유역에서 JNBC 보다 PERCENTILE이 가장 많은 분포를 보였으며, 충청도 지역에서는 유사한 결과를 나타내었다. 강우량의 등급화 결과를 살펴보면 PERCENTILE보다 JNBC의 등급이 높게 산정되었으며, 특히 전라도 지역과 충청도 지역에서 가장 큰 등급을 나타내었다. 또한 피해지역 호우특보 현황과 비교해 보면 JNBC가 유사한 것을 확인할 수 있다. Risk Matrix 결과에서 가장 피해가 심했던 세종, 대전, 충남, 충북, 광주, 전남, 전북지역을 살펴보면 PERCENTILE보다 JNBC가 잘 모사한 것을 확인하였다.

• 산업공학
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• 제17권1호
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• pp.1-12
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• 2004

In a modern semiconductor device manufacturing industry, statistical bin limits on wafer level test bin data are used for minimizing value added to defective product as well as protecting end customers from potential quality and reliability excursion. Most wafer level test bin data show skewed distributions. By Monte Carlo simulation, this paper evaluates methods and sample size effect regarding determination of statistical bin limits. In the simulation, it is assumed that wafer level test bin data follow the Poisson distribution. Hence, typical shapes of the data distribution can be specified in terms of the distribution's parameter. This study examines three different methods; 1) percentile based methodology; 2) data transformation; and 3) Poisson model fitting. The mean square error is adopted as a performance measure for each simulation scenario. Then, a case study is presented. Results show that the percentile and transformation based methods give more stable statistical bin limits associated with the real dataset. However, with highly skewed distributions, the transformation based method should be used with caution in determining statistical bin limits. When the data are well fitted to a certain probability distribution, the model fitting approach can be used in the determination. As for the sample size effect, the mean square error seems to reduce exponentially according to the sample size.

• 한국대기환경학회지
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• 제24권3호
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• pp.300-309
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• 2008

Variations in PM10 concentration between 2000 and 2005 from 84 urban air monitoring stations operated by the government were analyzed. The K-means cluster analysis was attempted using annual average and the 99th percentile of daily averages as parameters. The results obtained by excluding Asian dust episode days were compared with those obtained by using all available data. In any cases, the cluster with the highest mean concentration was mostly composed of stations in Seoul and Gyeonggi. Annual average of the cluster with the highest mean concentration showed a distinct decreasing trend, but that excluding Asian dust episode days did not show such a trend. Without Asian dust episode days high concentrations of monthly averages in March and April were also not observed. The effect of Asian dust was more pronounced in the 99th percentile of daily averages. The 99th percentile of daily averages of the cluster with the highest mean concentration was the highest in June following downs in April and May.

• 한국물환경학회지
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• 제24권6호
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• pp.676-681
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• 2008

The evaluation of the effluent water quality of sewage treatment plant is one of the most important factor in calculating total maximum daily loads (TMDLs). Current method to calculate 95% upper limit of effluent water quality of sewage treatment plant assuming normal distribution of data needs to be implemented in case of non-normal distribution. We have investigated the applicability of percentile ranking method as a non-parametric statistical analysis in case of non-normal distribution of data.