• Journal of the Chungcheong Mathematical Society
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• v.28 no.3
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• pp.491-497
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• 2015

In this paper, we have suggested an extended double Newton's method with sixth-order convergence by considering a control parameter ${\gamma}$ and a weight function H(s, u). We have determined forms of ${\gamma}$ and H(s, u) in order to induce the greatest order of convergence and established the main theorem utilizing related properties. The developed theory is ensured by numerical experiments with high-precision computation for a number of test functions.

• Journal of Preventive Medicine and Public Health
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• v.41 no.5
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• pp.323-330
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• 2008

Objectives : This study was conducted to examine the mediating function of body weight perception (BWP) on the relationship between body mass index (BMI) and unhealthy weight control behaviors (UWCB: e.g., fasting, or taking diet pills or laxatives) and between BMI and depressed mood, and to explore the effect of distorted BWP on UWCB and depressed mood among adult women. Methods : A regionally representative sample of 8,581 women aged 20-64 years residing in Seoul, the capital of Korea, completed the 2001 Seoul Citizens Health Indicator Survey which provides self-reported information about height, weight, BWP, UWCB, depressed mood, demo graphic/socioeconomic characteristics, and health-related behaviors. Data were analyzed using bivariate and multivariate logistic regression. Results : BMI was significantly associated both with UWCB and depressed mood, even controlling for all covariates. However, the magnitude and significance of each association was considerably attenuated when BWP was taken into account, indicating that BWP functioned, in part, as a mediator between BMI and UWCB and between BMI and depressed mood, respectively. Among the combinations of BMI and BWP, women who perceived themselves to be heavier than their actual BMls appeared more likely to use UWCB, whereas women who had a distorted BWP, either underestimation or overestimation as compared with their BMIs, tended to be at greater risk for depressed mood than those who had an undistorted BWP. Conclusions : These findings suggest that how women perceive their body weight may be an important predictor and/or mediator of UWCB and depressed mood among adult Korean women.