• Journal of Forest and Environmental Science
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• v.28 no.1
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• pp.24-29
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• 2012

This paper assesses the stmpage value of Korean white pine (Pinus koraiensis) stands in the Research Forest of Kangwon National University. Assessment was done by means of the cost value method (Faustmann formula) for age class I, Glaser method for age class II-V, and inversion market method for age class over VI. Generally the value of stumpage is calculated by the inversion market method in the market. However, immature trees and middle age class trees are not assessed in market, and the Korean forest is not old enough to harvest. So, when forests are damaged by attacks from forest fire, blight and harmful insects, the forest cannot be compensated for the loss from the government or insurance company. For this reason, the value of all-age class trees are calculated by using appropriate methods. As a result, the value of age I class stands (0.3 ha) is calculated as 1,786,305 (won), age II-Vclass stands (22.1 ha) 206,677,975 (won) and age VI class and over stands (24.8 ha) 523,789,603 (won).

• Journal of Korean Society of Forest Science
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• v.67 no.1
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• pp.52-59
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• 1984

A Gentan probability q(j) is the probability that a newly planted forest will be felled at age-class j. A future change in growing stock and yield of the forests can be predicted by means of this probability. On the other hand a state of the forests is described in terms of an n-vector whose components are the areas of each age-class. This vector, called age-class vector, flows in a n-1 dimensional simplex by means of $n{\times}n$ matrices, whose components are the age-class transition probabilities derived from the Gentan probabilities. In the simplex there exists a fixed point, into which an arbitrary forest age vector sinks. Theoretically this point means a normal state of the forest. To each age-class-transition matrix there corresponds a single normal state; this means that there are infinitely many normal states of the forests.

• Korean Journal of Child Studies
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• v.13 no.2
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• pp.53-64
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• 1992

The purpose of the present research was to investigate developmental trends in children's class-inclusion performance and to examine the influence of task characteristics(provision or deprivation of quantitative information and perceptual information) on a class-inclusion task. The subjects of this study were 96 children, 12boys and 12girls at each age level. 5, 6. 7 and 8 years of age. The experimental materials consisted of 12 stimulus boards which were constructed on the basis of picture cards used by Judd and Mervis(1979) and Lane and Hodkin(1985). The class-inclusion tasks were individually administered by the researcher. The data were analyzed by the statistical methods of t-test, one-way ANOVA and Duncan multiple range test. The results showed that (1) There were significant age differences in children's class-inclusion performance. That is, children's performance scores on the class-inclusion task increased with age.: (2) There were significant task characteristics differences in children's class-inclusion performance. That is, children performed better on the deprivation of quantitative information task than on the provision of quantitative information task.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.21 no.1
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• pp.45-63
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• 1991

This comparative study was designed to ascertain whether any differences existed between skeletal class Ⅱ malocclusion (

• Korean Journal of Human Ecology
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• v.19 no.4
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• pp.589-599
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• 2010

When the Korean government announced the lowering of the school entrance age from 6 to 5 years in an effort to increase the fertility rate, one candidate for the Seoul mayor rode on the slogan, 'one dong, one public kindergarten'. This study attempted to show the introduction of a preschool class for six-year-olds being used as analternative to lowering school entrance age in Sweden. First, the current state of preschool class, the Early Childhood Education and Care, and the education system in Sweden were described. Next, the background for the introduction of the preschool classes was analyzed. Thirdly, the effects of preschool class were evaluated from the perspectives of 6 year-olds as well as the institutiona land social status of the ECEC. Results from this study imply not only that the lower school entrance age policy should be abolished but also preschool classes could be considered as an alternative.

• Health Policy and Management
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• v.13 no.4
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• pp.99-114
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• 2003

This study was performed to determine the effect of social class distribution as measured by lower social class rate on all cause and cause specific mortality in Korea. I obtained data on social class, fiscal autonomy of municipalities, number of medical doctors, region(Si/Gun) from 1955 Korea Census Data and Regional Statistics Data. And all of the data on mortality adjusted for age for 1995 for each district from the National Statistics Office. Lower social class rate ranged from 18.9％ for Kangnam gu to 85.7％ for Imsil gun and age standardized mortality ranged from 385/100,000 population for Kangnam go to 803/100,000 population for Sinan gun. Lower social class showed had a significant correlation with total mortality adjusted for age(r=0.81, p<0.0001). The association of the rate to total mortality remained highly significant after adjusted for number of medical doctors per 1,000 population, fiscal autonomy of municipalities and region(p<0.0001). Effects of the lower social class were also found for neoplasm (p=0.0008)； cardiovascular disease (p<0.0001)； infectious disease(p=0.0115)； respiratory disease(p=0.0085)； gastrointestinal disease(p<0.0001)； accident ＆ poisoning (p<0.0001). The findings suggest that policies that deal with the inequality in social class may have an important impact on the health of the population.

• Journal of the Korean Wood Science and Technology
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• v.42 no.6
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• pp.646-652
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• 2014

This study was carried out to test the possibility that tracheid length of red pine growing in Sokwang-ri in Uljin could be used as one of variables to estimate its wood properties. For the study, forest stands of V (500 m a.s.l.) and VIIII (900 m a.s.l.) age class plots were selected in the region, and three trees in each plot were investigated. The tracheid length was separately measured for early- and latewood. It took approximately 25 and 40 years for V and VIIII age class stands, respectively, until the length was stabilized. The lengths in latewood were 3.14 (V age class) and 3.30 (VIIII age class) mm, and in earlywood 2.98 (V age class) and 3.15 (VIIII age class) mm. The lengths in latewood therefore were longer than in earlywood and the lengths for VIIII age class were longer than for V age class. However, the ratio between their lengths in early- and latewood was the same as 0.96 in all age classes. It might be verified whether this ratio can be used as a variable to test the wood property according to provinces by comparing it with others.

• 한국사회정책
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• v.25 no.2
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• pp.281-304
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• 2018

This paper aims at analysing what impacts the experience of self-employed business have had on the income mobility. Since 2000s, the flexibilization of labor market and the population aging led to the increase of the number of self-employed job as many retirees at the age of early 50s has set up the self-employed business as a bridge job. However, previous researches just have emphasized on the impoverishment of the self-employed, but not focused on what different effects the experience of self-employed had on the income class mobility by age group. This paper compares the difference in the income class mobility by age group and employment status, and analyses its longitudinal trends. According to the result, as a whole the experience of self-employed has positive effect on the upper mobility of income class, but it become disadvantageous for the upper mobility as the age goes up. When belonging to the age group over 60s, the experience of self-employed rather increases the risk of lowering income class. Just as the experience of self-employed has different effects on income class mobility by age group, so the differentiated measures for age groups are demanded.

• Journal of Forest and Environmental Science
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• v.9 no.1
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• pp.1-9
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• 1993

In the fall of 1992, growth characteristics and cone-bearing behaviour of crown top shoots were investigated on Pin us koraiensis trees, belonging to age class VII and IV, in the School Forests, College of Forestry, Kangwon National University to obtain basic information for the design of Korean pine cone harvesting machine. The results were summarized as follows. 1. The length of terminal main shoots and lateral shoots of the trees in age class IV was 27~56cm and 18~47cm, respectively, both of which were significantly higher than those of the trees in age class VII. 2. There was no significant difference between two age classes in the branching angle ($24{\sim}89^{\circ}$) of lateral shoots and in the diameter (10~30mm) of two-year-old main shoots. However, one-year-old terminal main shoots of age class IV showed the higher diameter (9~18mm) than those of age class VII. 3. Mean cone number per tree was 5, and mean fresh weight of cone was 272g. No significant difference was found in these traits between both age classes. 4. Cones, on an average, hung on the two-year-old main shoots 15cm above the basal ends in age class VII and 33cm above in age class IV. Both lengths are equivalent to one half and four fifths of the shoots, respectively. 5. The fresh weight range of crown-top shoots containing cones was 1.0~7.4kg.

• Korean Journal of Environment and Ecology
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• v.22 no.4
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• pp.396-408
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• 2008

Gwangtan-myeon, Paju-si, Gyeonggi-do was classified as a 4 grade age-class deciduous tree forest, however as a result of vegetation survey, this site was found to consist of natural forest with deciduous trees, thus causing difficulty in judging which age class it belongs to. Subsequently, the necessity of drawing up a detailed stock map plan was raised. For this reason, this research was designed to propose a mapping method for a detailed stock map plan based on a detailed survey on actual vegetation, vegetation structure, and analysis data on tree rings. The detailed analysis of actual vegetation pattern showed that there exist 22 patterns of vegetation, in which the natural forest has 11 patterns, such as Quercus mongolica forest and Q. variabilis forest, etc. while the artificial forest was found to have 6 patterns including Castanea crenata, etc. In order to verify their age-class, this research measured a tree age by collecting 42 quadrats and 89 specimen tree cores on the basis of a detailed actual vegetation map; as a result, an artificial forest and oak trees with small diameters located at low-lying areas, was categorized as 2-grade age class(covering 29.8%), and other areas were judged to be available for land use as 3-grade age-class(covering 57.6%) while the areas judged to be 4-or-more grade age-class (covering 8.8%) was impossible for land use because they are located on a steep slope ridge line on a boundary. In case a proposed site for a small-scale development is judged as a natural forest with deciduous trees as mentioned above, it is necessary that a detailed stock map plan should be drawn up through a detailed investigation into actual vegetation and analysis of plant gathering structure & specimen trees. A detailed stock map plan includes the data that makes it possible to comprehensively judge natural property, scarcity, and diversity of vegetation; thus, it is considered that a detailed stock map plan will be useful in judging the development propriety of a small-scale site.