• Clinical and Experimental Pediatrics
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• v.57 no.2
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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.

• Survey Research
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• v.12 no.3
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• pp.173-186
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• 2011

We introduced the methodologies used to construct the longitudinal weights and cross-sectional weight that are required for the analysis of Korea Youth Panel Survey. To analyze the longitudinal dynamic change of the population, we derived the longitudinal weight through nonresponse adjustment based on logistic regression and post-stratification. Cross-sectional weights that are necessary to produce an asymptotically unbiased estimator of the population parameter were constructed through simple nonresponse adjustment based on overall response rate and post-stratification.

• Journal of the Korea Society of Computer and Information
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• v.14 no.7
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• pp.9-15
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• 2009

The fuzzy weighted mean classifier is one of the most common classification models and could achieve high performance by adjusting the weights. However, the weights were generally decided based on the experience of experts, which made the resulting classifiers to suffer the lack of consistency and objectivity. To resolve this problem, in this paper, a weight deciding method based on the statistics of the data is introduced, which ensures the learned classifiers to be consistent and objective. To investigate the effectiveness of the proposed methods, Iris data set available from UCI machine learning repository is used and promising results are obtained.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.6 no.1
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• pp.3-12
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• 1988

The objective of this paper is to study the characteristics of combination method to correct both angle and distance errors simultaneously based on the least square adjustment methods. Changing the standard errors of distance and angle, the simulation errors of triangultion, trilateration, and combination result in some 39.8%, 33.9%, and 26.3% respectively. As the above, combination method shows more consistent accuracy than other methods. When considering the weight factor about error elements with independence, the diminishing rate of simulated average standard error represents a various change in each method. But considering them simultaneously, it shows a remarkable rate of diminishing 75.5%, 74.1%, and 69.2% in each method. And also, by growing the weight factor, accuracy of triangulation method is growing, whereas that of trilateration is diminishing. Therefore, determining the reasonable weight factors of distance and angle errors simultaneously in the analytical combination method, this method is expected to be one of more accurate and more effective methods for determining horizontal positions on the earth.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.2
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• pp.259-264
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• 2017

Birth weight of a new born baby provides very important information in evaluating many clinical issues such as fetal growth restriction. This paper analyzes birth weight data of babies born in Korea from 2011 to 2013, and it shows that there is a biologically implausible distribution of birth weights in the data. This implies that some errors may be generated in the data collection process. In particular, this paper analyzes the relationship between gestational period and birth weight, and it is shown that the birth weight data mostly of gestational periods from 28 to 32 weeks have noticeable errors. Therefore, this paper employs the finite Gaussian mixture model to classify the collected data points into two classes: non-corrupted and corrupted. After the classification the paper removes data points that have been predicted to be corrupted. This adjustment scheme provides more natural and medically plausible percentile values of birth weights for all the gestational periods.

• Journal of the Korean Society for Railway
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• v.19 no.2
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• pp.135-144
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• 2016

It is essential to lighten the weight of switch girders in order to reduce their costs of manufacturing and make it easier to use them in construction. Lightening the weight of switch is also important to the Maglev 3-way switches system, however, the design variables should be considered very carefully if lightening is to be applied to the system, because these variables are vitally related to the levitation stability. Because Urban Maglev trains have a structure in which train bogie wraps around the guiderail, the adjustment of a girder's height is a possible way to reduce the weight. The safety of the application of this concept is ensured by repeated experiments in a test bed, however, due to a lack of space and budget limits, the design parametric study for the system model can substitute for actual application. The purpose of this paper is to study the design parameters that are concerned with levitation stability while a Maglev train is running on the Maglev 3-way system depending on the weight of the switch girders. In this study, switch girder weight is reduced by adjustment of girder height and girders are and modeled as a flexible body. The effect of the adjustment of girder height on the levitation stability can be analyzed by comparing the velocity of the train when it passes the switch girders, with the lateral gap, and the levitation gap which are obtained from the co-simulation of the Maglev train's dynamics model and flexible switching system. The results of this research will be used to design a Maglev switch.

• Research in Community and Public Health Nursing
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• v.30 no.1
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• pp.90-98
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• 2019

Purpose: The purpose of this study is to identify the association between maternal feeding practices and excessive weight gain in infants. Methods: This study adopted a cross-sectional design and included 240 pairs of mothers and their infants (129 boys and 111 girls) in public healthcare centers in the Daejeon area in South Korea. Via multivariate analyses, the association between maternal feeding practices and excessive weight gain in infants was identified. Results: Among 240 infants in this study, 39 (16.3%) infants gained excessive weight during 12 months after birth. Using multivariate logistic regression with adjustment for covariates, more than 7 months of exclusive breastfeeding was associated with a reduced likelihood of excessive weight gain in infants during the 12 months after birth (adjusted odds ratio: 0.39, 95% confidence interval: 0.02~0.81, p=.029). Conclusion: Based on these results, nurses in communities and clinics should educate mothers on the importance of longer durations of exclusive breast feeding and develop strategies for encouraging such behavior. Furthermore, support for exclusive breast feeding should be provided in various settings.

• Journal of the Korean Statistical Society
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• v.24 no.2
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• pp.349-360
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• 1995

This paper deals with the robustness properties of the minimum disparity estimation in linear regression models. The estimators defined as statistical quantities whcih minimize the blended weight Hellinger distance between a weighted kernel density estimator of the residuals and a smoothed model density of the residuals. It is shown that if the weights of the density estimator are appropriately chosen, the estimates of the regression parameters are robust.

• Journal of the Korean Geophysical Society
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• v.8 no.1
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• pp.23-33
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• 2005

The digital surface model (DSM) is used for several purposes in photogrammetry, remote sensing and laser scanned data such as orthoimage production, contours erivation, extraction of height information. Creation of a surface model from point-clouds (3-D sparse points) that can be derived from stereo imagery and range data (e.g. laser scanned data) can be done with several mathematical interpolation models. In this paper, thin-plate-spline (TPS) is used for digital surface modeling. Determination of suitable weight is an important problem in thin-plate function for a surface. The Voronoi algorithm has been proposed as a method for determination of the weight in thin-plate-spline. In this paper, methods has been tested for different surfaces. The results show that thin-plate-spline can be independent of weight.

• Journal of the Korean Society of School Health
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• v.14 no.1
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• pp.115-130
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• 2001

Dieting behaviors prevail among most women and are highly increasing among female adolescents who don't have to lose weight. The dieting behaviors of normal or low weight groups are highly related to the negative impact of health risk behaviors. We need a strategy for intervening in the dieting behaviors of relevant groups. With this background, a study was conducted to examine the current situation of dieting behaviors and related factors in middle school girls, and to provide guidelines for the relevant dieting group. This survey was carried out by self-questionnaires passed out to 901 middle school girls from 3 middle schools in Seoul. Data were collected from April 10th, 2000 to April 17th, 2000 and 794 respondents' data were finally selected for analysis. The instruments of this study were Shin's scale for effects of mass-media, Birleson's depression self-rating scale translated by shim, Rosenberg's self-esteem scale, Smilkstein's Family APGAR score translated by Yoon, Kim's school-related adjustment scale. The credibility of instruments was 0.41~0.83 in the pilot study and 0.70~0.86 in the main study. The summary of results was as follows: 1. The general characteristics of respondents were analyzed. In comparison of grade and dieting behaviors, the subjects of the group perceived that their body image was obeser than their real body image and their ideal body image was slenderer than their current body image. A dieter's body image was seriously distorted. 2. The dieting behaviors were analyzed. The Subjects' BMI was within the normal to low range -- they didn't have to lose weight. But actually 47.3% of the respondents were dieters. Their main dieting methods were exercise(71.8%), computer games(64.9%) such as DDR and pump, and intake reduction(64.1%). Most dieters were using desirable methods such as exercise and intake control. But unhealthy methods such as saunax, smoking and harmful drug-use were also used by a few dieters. The main reason for dieting was attractiveness. The chief resources of dieting methods were mass-media(67.8%), friends(64.3%), and parents & relatives(35.1%). Only a few subjects obtained the information from health professionals. While they were trying to lose weight, 42.1% of the subjects experienced side effects such as dizziness(45.0%), apathy(20.5%), appetite loss(18.5%), amenorrhea and the irregularity of the menstrual cycle(16.6%). 3. The relationship between dieting behaviors and factors was analyzed. Dieting behaviors were significantly related to the experience of menarche, the experience of dating with heterosexuals, perceived body image, self-esteem, depression, family's relationship, school instruction-related adjustment, school life-related adjustment, and the effect of mass-media. After that, the multiple logistic regression was used. The analysis revealed that dating, perceived body image, the experience of menarche and the effect of mass media were significant factors. In conclusion, strategies for preventing irrelevant dieting behaviors are urgently required to enhance female adolescents' ability to choose the right information from countless others and to recognize their optimum body image.