• Journal of the Korean Data and Information Science Society
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• 제12권2호
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• pp.35-45
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• 2001

We introduce a new percentile envelope for diagnosing supernormality in regression analysis. Furthermore, we compare this percentile envelope, which is much simpler and easier, with Atkinson's and Flack and Flores' envelopes. Using percentile envelope, we investigate characteristics of normal probability plots with envelope for error distributions when supernormality is occurred. We give cautions that test result for normality assumption of errors can be reached the wrong conclusion by supernormality.

• Journal of the Korean Data and Information Science Society
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• 제21권2호
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• pp.291-296
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• 2010

In this paper, we consider a versatile test based on percentile tests. The versatile test may be useful when the underlying distributions are unknown or quite different types. We consider two kinds of combining functions for the percentile statistics, the quadratic and summing forms and obtain the limiting distributions under the null hypothesis. Then we illustrate our procedure with an example. Finally we discuss some interesting features of the test as concluding remarks.

• Journal of Nutrition and Health
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• 제30권7호
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• pp.832-839
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• 1997

The purpose of this study is to survey the prevalence of obesity assessed on the basis of height and weight among students in primary and secondary schools in the metropolitan area of Seoul, Korea during the period of 1979 to 1996. The major findings are as follows ; 1) The fiftieth percentile values of BMI have increased more in mid-ranged age group than upper(16-17 years old) and lower(6-7 years old) ranged age groups. 2) The prevalence of obesity by standard weight of height was higher among male students than female students and students in the primary schools showed higher weight increase than adolescent age(12-17 years old) group. As a whole, the prevalence of obesity over last 18 years has increased 4.6 times in males and 3.2 times in females. 3) Judged on the basis of the BMI 90th, 95th percentile values of 1979 , the prevalence of obesity among male students showed higher increases than among female students. Higher increase was also observed among primary school students than among middle and high school students. Increase of weight was higher for the $\geq$95th percentile group than the 90-95th percentile group. 4) Judged on the basis of the BMI, 90th, 95 th percentile values of NHANES-I, the $\geq$95th percentile group showed higher increase in the prevalence of obesity than the 90-95th percentile group. According to the 1996 data, severe obesity group ($\geq$95th percentile) was about two times of NHANES-I in male primary school students, while the number for female middle and high school students was about 1/5 of NHANES-I.

• 대한한방소아과학회지
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• 제37권4호
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• pp.1-14
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• 2023

Objectives This study aimed to evaluate the correlation between pediatric weakness scale scores and growth indices. Furthermore, we intended to calculate the cut-off values for diagnosing Kidney Weak Children through growth indices. Methods A total of 193 patients, aged 6 - 12 years, underwent both the pediatric weakness scale and bone age assessment, and the correlations between the pediatric weakness scale and growth indices were analyzed. Moreover, the cut-off values for diagnosing Kidney Weak Children were calculated. Differences in bone age and predicted height between the normal group and Kidney Weak Children, classified according to the calculated cut-off values, were analyzed. Results The weakness of the Shin or kidney system was significantly correlated with the height percentile, weight percentile, differences in current height percentile and mid parental height percentile, differences in predicted height and mid parental height, and differences in bone age and chronological age. When the criteria for diagnosing Kidney Weak Children is set at "height percentile of ≤25% and weight percentile of ≤25%", the sensitivity and specificity of the cut-off value were maximized. The cut-off values for weakness of the Shin or kidney system were 9 in children aged 6 - 9 years and 10 in children aged 10 - 12 years. Conclusions To diagnose Kidney Weak Children, the cut-off values of weakness of the Shin or kidney system were 9 in children aged 6 - 9 years and 10 in children aged 10 - 12 years.

• 한국신뢰성학회지:신뢰성응용연구
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• 제1권1호
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• pp.55-63
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• 2001

In this paper, we utilize the asymptotic variance of $C_{pk}$ to propose a two-sided confidence interval based on percentile-t bootstrap method. This confidence interval is compared with the ones based on the standard and percentile bootstrap methods. Simulation results show that percentile-t bootstrap method is preferred to other methods for constructing the confidence interval.l.

• 한국시뮬레이션학회논문지
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• 제9권4호
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• pp.67-75
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• 2000

Often system analysts are interested in the estimation of percentile for system performance. For instance, in PERT network system, the percentile that the project. Typically the control variate method is used to reduce the variability of mean response using the correlation between the response and the control variates with a little additional cost during the course of simulation. In the same spirit, we apply this method to estimate the percentile of project completion time in PERT system, and evaluate the efficiency of the controlled estimator for its percentile.1 Simulation results indicate that the controlled estimators are more effective in reducing the variances of estimators than the simple estimators, however those tend to a little underestimate the percentiles for some critical values. We need more simulation experiments to examine such a kind of bias problem. We expect this research presents a step forward in the area of variance reduction techniques of stochastic simulation.

• Communications for Statistical Applications and Methods
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• 제28권6호
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• pp.627-641
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• 2021

An asymmetric least squares estimation method has been employed to estimate linear models for percentile regression. An asymmetric maximum likelihood estimation (AMLE) has been developed for the estimation of Poisson percentile linear models. In this study, we propose generalized nonlinear percentile regression using the AMLE, and the use of the parametric bootstrap method to obtain confidence intervals for the estimates of parameters of interest and smoothing functions of estimates. We consider three conditional distributions of response variables given covariates such as normal, exponential, and Poisson for three mean functions with one linear and two nonlinear models in the simulation studies. The proposed method provides reasonable estimates and confidence interval estimates of parameters, and comparable Monte Carlo asymptotic performance along with the sample size and quantiles. We illustrate applications of the proposed method using real-life data from chemical and radiation epidemiological studies.

• Clinical and Experimental Pediatrics
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• 제57권2호
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• pp.79-84
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• 2014

Purpose: Overweight can be defined by the body mass index (BMI) and is likely associated with an increased cardiovascular disease risk. However, waist circumference (WC), a central adiposity index, may be a better indicator of cardiovascular disease risk. Studies comparing the effects of BMI and WC on cardiovascular risk factors, such as high blood pressure (BP), are rare in adolescents. Methods: We analyzed the correlations of BMI and WC with BP in 3,363 Korean adolescents (aged 10-19 years), using data from the Korean National Health and Nutrition Examination Surveys (2009-2011). Results: Systolic BP (SBP) in both sexes and diastolic BP (DBP) in boys were higher in the high BMI (>85th percentile) and high WC (>90th percentile) groups. High BMI and high WC were positively correlated with high SBP (>90th percentile) in both sexes, and high DBP (>90th percentile), in boys. BMI maintained its positive associations with SBP, DBP, high SBP, and high DBP in the normal weight ($BMI{\leq}85th$ percentile) and overweight (BMI>85th percentile) groups in both boys and girls, as well as in all subjects of both sexes, even after adjustment for WC. However, WC did not correlate with SBP, DBP, high SBP, or high DBP after adjustment for BMI in any group in either sex. Conclusion: In Korean adolescents, BMI correlated better with BP and high BP levels than WC. Further, BMI was positively associated with BP and high BP in the normal weight group as well as in the overweight group.

• 대한간호학회지
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• 제25권2호
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• pp.279-294
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• 1995

The purpose of this study was to determine values and value changes in clinical nurses in clinical situations. A survey was conducted of 200 nurses of one of university hospital in Seoul Korea. This study was conducted between July 1 and July 5, 1994, using the Survey of Interpersonal Values (SIV) developed by L. V. Gordon, and standardized for Korea by Kyung Hye Lee & Eung Yun Hwang. The results of the study were as follows, 1. The clinical nurses surveyed showed Independence(18.32 : 63rd percentile) as their highest value, with Support(14.8 : 62nd percentile) next and then Benevolence(16.28 53rd percentile), Leadership(9.06 : 46th percentile), Conformity(18.15 : 42nd percentile) and Recognition(18.32 : 41s1 percentile) in that order in the area of general values. Using a standardised women's value Indicator, the clinical nurses value orientation was within the 32nd∼69th percentile indicating means found among Korean women in general. 2. Looking at how the values were related to demographics, Leadership was most highly valued among the 30∼34 year olds and least valued among the 25∼29 year olds. Unmarried nurses valued Independence more than married nurses did, and junior college graduate nurses valued Conformity more than baccalaureate graduate nurses did. 3. The study showed that the values of with less than one year (16.00) clinical experience were higher than those who had over 10 years (13.60) clinical experience (p<.05). Therefore clinical experience did not positively influence value orientation for clinical nurses. 4. There was no significant differences in the value of nurses in relation to their workplace, their level of motivation, or their aptitude. The study shows that clinical nurses have similar values compared with ordinary Korean women. This means that professional nurses may not be able to satisfy client needs and also that they do not have satisfaction and a positive attitude regarding the nursing profession. Therefore it is suggested that new strategies and continuing education programs be established to help clinical nurses fomulate higher values.

• Korean Journal of Otorhinolaryngology-Head and Neck Surgery
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• 제61권12호
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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.