• Journal of Korean Society of Industrial and Systems Engineering
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• v.25 no.6
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• pp.17-22
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• 2002

In this paper, We consider some generalization of these five basic indices to cover non-normal distribution. The proposed generalizations are compared with the five basic indices. The results show that the proposed generalizations are more accurate than those basic indices and other generalization in measuring process capability. We compared an estimation methods by Clements with based on sample percentiles WVM to calculate the proposed generalization as an example The results indicated that Clements method is more accurate than percentile method, WVM in measuring process capability But the calculations of percentile method are easy to understand, straightforward to apply, and show be valuable used for applications.

• Journal of the Korean Statistical Society
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• v.24 no.2
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• pp.551-562
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• 1995

We consider the iterated bootstrap method in regression model with heterogeneous error variances. The iterated wild bootstrap confidence intervla of the mean response is considered. It is shown that the iterated wild bootstrap confidence interval has coverage error of order $n^{-1}$ wheresa percentile method interval has an error of order $n^{-1/2}$. The simulation results reveal that the iterated bootstrap method calibrates the coverage error of percentile method interval successfully even for the small sample size.

• Journal of the Korean Data and Information Science Society
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• v.6 no.1
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• pp.73-83
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• 1995

We construct the approximate bootstrap confidence intervals for reliability (R) when the distributions of strength and stress are both normal. Also we propose percentile, bias correct (BC), bias correct acceleration (BCa), and percentile-t intervals for R. We compare with the accuracy of the proposed bootstrap confidence intervals and classical confidence interval based on asymptotic normal distribution through Monte Carlo simulation. Results indicate that the confidence intervals by bootstrap method work better than classical confidence interval. In particular, confidence intervals by BC and BCa method work well for small sample and/or large value of true reliability.

• Korean Journal of Otorhinolaryngology-Head and Neck Surgery
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• v.61 no.12
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• pp.681-685
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• 2018

Background and Objectives This study was performed to evaluate the long-term effect of adenotonsillectomy on childhood growth by examining preoperative growth status and presenting symptoms. Subjects and Method One hundred and four patients who underwent adenotonsillectomy from January to December 2009 were enrolled in this study. Clinical data were collected from medical record reviews and through the administered questionnaire. We investigated symptoms and growth changes during 5 years following the surgery. Results The mean age of patients was $6.0{\pm}1.94$ years (range, 3-10), with the male to female ratio of 62:42. Pre-operative symptoms were significantly improved after the surgery. The mean pre-operative height and weight percentiles were $53.6{\pm}27.4$ and $59.6{\pm}29.2$ at initial evaluation, and $67.1{\pm}26.4$ and $59.6{\pm}28.6$ at 5 years post adenotonsillectomy (p<0.001, p=0.989), respectively. An increase in height percentile was more prominent in patients whose pre-operative height percentile was less than 50 compared to those with a percentile of 50 or more (p<0.001). Weight percentile was significantly increased in those with the pre-operative weight percentile of less than 50 and decreased in patients with a percentile of 50 or more. Conclusion Adenotonsillectomy has a positive effect on height growth in children with adenotonsillar hypertrophy, especially in patients whose height percentile is less than 50. Weight gain also can be expected in preoperative low-weight children.

• Journal of Korean Society on Water Environment
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• v.24 no.6
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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.

• Journal of the Korean Society of Safety
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• v.29 no.1
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• pp.31-36
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• 2014

In this study, the methodologies for evaluating the low-flow at the ungauged watershed are reviewed and assessed. The ungauged watershed can be classified into different situations such as the partially recorded watershed and the completely ungauged watershed. The extension method and the percentile method are used to evaluated the low-flow at the partially recorded watershed. The drainage-area ratio method and the regional regression method are used at the completely ungauged watershed. These four methods are applied and validated based on the hydrological and geometric data acquired from unit watersheds in Han River basin for TMDLs. In case of partially recorded watershed, the values of low-flow evaluated by the extension method are in better agreement with measured flow-rate rather than those by the percentile method. In case of completely ungauged watershed, the drainage-area method is broadly used to estimate the low-flow. It must be paid attention to consider the treated sewage discharge produced at watersheds when applying the method.

• Korean Journal of Community Nutrition
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• v.18 no.5
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• pp.525-538
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• 2013

The purpose of this study was to provide information on obesity assessment for Koreans. Among total of 1012 research papers enlisted in the Korean J Community Nutrition form 1996 to 2011, 248 articles were examined in which subjects were divided into more than 2 groups by obesity rate. About the method of anthropometric data collection, more than half of the research papers examined 52.5% and 28.7% of studies utilized the directly measured data and self-described data, respectively. About the utilization of obesity assessment methods, indirect methods of weight-height index (BMI, BMI percentile, and R$\ddot{o}$hrer index) and PIBW (WLR, Broca index, and KDA) were 62.4% and 23.2%, respectably, and the direct method of percent body fat assessment was only 9.3%. The most frequently utilized methods were WLR in under primary and primary school children, and BMI in the middle and high school students and in adults. For primary school students, WLR was the most frequently utilized method up to 2007, but it changed to BMI percentile afterward. Broca Index was no longer utilized since 2008. There were no articles utilizing BMI percentile and R$\ddot{o}$hrer index for obesity assessment in adults. Criteria for obesity assessment were not consistent among research papers: for example, % body fat, 19~40%; BMI, 20~30; BMI percentile, 85th or 95th. In the case of PIBW, 120% of ideal weight was the most frequently utilized criterion for obesity. Based on these findings, we suggest that proper methods and criteria of obesity assessment for each age group should be determined and proclaimed.

• The Journal of Pediatrics of Korean Medicine
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• v.26 no.4
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• pp.24-31
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• 2012

Objectives: The purpose of this study was to estimate differences in physical growth according to sleep during preschool period. Methods: Difference of height and BMI percentile according to quality and quantity of sleep obtained through survey from 377 preschool children was measured using statistical method. Results: There was no significant difference in height and BMI percentile according to bedtime, rising hour, sleeping hours and sleeping environment. Children who had woken up more from scare during sleep showed smaller height percentile. Conclusions: Children who woke up more from scare during sleep could have smaller height.

• Journal of Community Nutrition
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• v.1 no.2
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• pp.81-87
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• 1999

Body mass index(BMI) is recognized as one of the most useful indexes for adiposity in children and adults. This study was conducted to provide information on BMI distribution by age and sex in Korean children, and to identify sociodemographic factors that affected BMI among children. The study was conducted on 2376 children(boys 1184, girls 1192) living in a middle-size city in Korea. Subjects were selected from the primary schoolchildren in grades 1-6 using the two-stage sampling method. Their mean age was 9.4 years. The percentile of BMI tended to increase as age increased in both sexes. The 85th percentile for boys, aged 6-12 years, was 19.8kg/㎡, and the 95th percentile was 22.5kg/㎡. The 85th percentile for girls, aged 6-12 years, was 18.9kg/㎡, and the 95th percentile was 21.5kg/㎡. Multiple regression analysis was carried out to predict BMI from percent ideal body weight (PIBW), age and sex. After adjusting PIBW and age, BMI for boys was 0.062kg/㎡ lower than that for girls. One year of age increased BIM by 0.55kg/㎡. The prevalence rate of overweight and obesity based on PIBW was 15.8% and 15.0% for boys, and 14.0% and 11.0% for girls, respectively. Demographic factors such as sex, age, and parents' obesity influenced children's BMI. After adjusting for sex, age and parents' BMI, the presence of another children in family, and mother's employment status showed a strong effect on children's BMI. The results suggest an age-sex specific BMI distribution of Korean children. The present study also provides direct evidence of a correlation between early life environmental factors, such as presence of siblings or mother's employment, and BMI level in Korean children.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.1
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• pp.48-56
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• 2019

The objective of this study was to examine measuring agreement between middle phalanx of the third finger and cervical vertebrae analysis for assessing skeletal maturity according to body mass index percentile. A retrospective chart view was used to select patients with body mass index data, hand - wrist radiographs and lateral cephalograms of same day. The patients were divided into 4 groups by body mass index percentile. The hand - wrist radiographs were analyzed using modified middle phalanx of the third finger method and the lateral cephalograms were categorized according to cervical vertebral maturation stage. The degree of agreement between the 2 methods of analyzing skeletal maturation was measured by calculating weighted kappa statistic according to body mass index percentile group. There was a good agreement between the 2 methods in the entire body mass index percentile group. According to the body mass index percentile group, the agreement was found to be different, and the pattern was different between boys and girls. Pediatric dentist should consider sex and weight status when evaluating growing children and adolescents because it can affect the agreement of 2 method of analyzing skeletal maturation.