• Journal of Korean Society of Forest Science
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• v.111 no.4
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• pp.622-629
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• 2022

The study aim was to derive a stem taper equation for Phyllostachys pubescens, a type of bamboo in South Korea, and to develop a stem volume table. To derive the stem taper equation, three stem taper models (Max & Burkhart, Kozak, and Lee) were used. Since bamboo stalks are hollow because of its woody characteristics, the outer and inner diameters of the tree were calculated, and connecting them enabled estimating the tree curves. The results of the three equations for estimating the outer and inner diameters led to selection of the Kozak model for determining the optimal stem taper because it had the highest fitness index and lowest error and bias. We used the Kozak model to estimate the diameter of Phyllostachys pubescens by stem height, which proved optimal, and drew the stem curve. After checking the residual degree in the stem taper equation, all residuals were distributed around "0", which proved the suitability of the equation. To calculate the stem volume of Phyllostachys pubescens, a rotating cube was created by rotating the stem curve with the outer diameter at 360°, and the volume was calculated by applying Smalian's method. The volume of Phyllostachys pubescens was calculated by deducting the inner diameter calculated volume from the outer diameter calculated volume. The volume of Phyllostachys pubescens was only 20~30% of the volume of Larix kaempferi, which is a general species. However, considering the current trees/ha of Phyllostachys pubescens and the amount of bamboo shoots generated every year, the individual tree volume was predicted to be small, but the volume/ha was not very different or perhaps more. The significance of this study is the stem taper equation and stem volume table for Phyllostachys pubescens developed for the first time in South Korea. The results are expected to be used as basic data for bamboo trading that is in increasing public and industrial demand and carbon absorption estimation.

• Korean Journal of School Psychology
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• v.8 no.2
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• pp.133-152
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• 2011

This is a short-term longitudinal study investigating the relationships between changes in mental health and academic burnout among Korean middle school students. Study sample consisted of 409 middle school students in Seoul provision, with 161 male, 216 female, and 32 unidentified. Both Symptom Check List(SCL-47) and Maslach Burnout Inventory-Student Survey(MBI-SS) were used. In order to examine the pattern of changes in mental health and academic burnout among students, standardized residuals were calculated using regression equations which were then put into canonical correlation analysis. The results of this study are as follows. First, according to Function 1, among sub-factors of mental health, decreases in depression, compulsion, anxiety, and hostility were particularly associated with decreases in exhaustion and cynicism among academic burnout. Put in another way, students who showed increases in depression, compulsion, anxiety, and hostility experienced more academic exhaustion and cynicism. Second, according to Function 2, increases in phobic anxiety, compulsion with decreases in anxiety, depression were associated with decrease in academic exhaustion and increase in cynicism. Considering Russell's dimensional theory of emotion, Function 1 showed that mental health symptoms including both aroused and non-aroused affects were related with increases in exhaustion and cynicism while Function 2 showed that mental health symptoms including only aroused aspects were related with decrease in exhaustion and increase in cynicism. Thus, a conclusive intervention program seems to be required to deal with both aroused and non-aroused affects of students who are experiencing increased exhaustion and cynicism. On the other hand, an intervention program focused on aroused affects seems appropriate to students who are experiencing decreased exhaustion and increased cynicism. This study has its value in that it has enhanced understanding of students in school and counseling settings by revealing the relationships between mental health and academic burnout among adolescents and suggested differentiated intervention strategies based on patterns of students' academic burnout.

• Tuberculosis and Respiratory Diseases
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• v.50 no.3
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• pp.320-333
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• 2001

Background : Peak expiratory flow (PEF) provides a simple, quantitative, and reproducible measure of the existence and severity of airflow obstructions. Peak flow meters are designed to monitor the condition asthma patients. There are many reports showing the normal predicted value of PEF in other countries. Studies on healthy Korean adults have been performed in a relatively small sample number and a lower limit for the normal value was not reported. Therefore, an attempt to provide normal predictive PEF value with a lower limit was made. Method : The PEF(Mini-Wright Peak Flow Meter) measurements and spirometry were done in 233 men and 631 women without history of respiratory disease. All subjects were non-smokers with no respiratory symptoms. The normal predictive value and its lower limit were developed by multiple regression analysis. The result was compared with regression equations in other reports. Results : The regression equation for the normal PEF predictive value(L/min) is $25.117+4.587{\times}$Age(year)-$0.064{\times}Age^2+2.931{\times}$Height(cm) in men($R^2=025$), and 146.942-$0.011{\times}Age^2+1.795{\times}$Height(cm)+$0.836{\times}$Weight(kg) in women($R^2=0.21$). The regression equation for the lower limit of this value (L/min) is $25.117+4.587{\times}$Age(year)-$0.064{\times}Age^2+1.936{\times}$Height(cm) in men, and $146.942-0.011{\times}Age^2+1.232{\times}$Height(cm)+$0.481{\times}$Weight(kg) in women. The residuals were normally distributed. The PEF in Korean males was sililar to those reported in British and Japanese subjects. The PEF in Korean females was similar to that in British subjects, but higher than the PEF in Japanese subjects. The lower limit of normal value was 71% of normal predictive PEF value in men and 76% in women. Conclusion : The normal predictive PEF value and its lower limit was measured from 233 male and 631 female asymptomatic, lifelong non-smoking participants. The normal predictive value was different from those of other studies on Korean subjects. Therefore, further studies are required.