• Journal of Korean Society of Forest Science
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• v.109 no.4
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• pp.461-467
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• 2020

The aim of this study was to utilize Kozak's stem taper model to develop both a stem taper equation and a stem volume table for Criptomeria japonica, a tree species distributed across Korea. A total of 1,000 sample trees were cut and collected across the country to measure their diameters by stem height. The equation was then used to estimate examine their stem shapes. Our results show that the Fitness Index for the equation was 98.7%, the Mean Absolute Deviation (MAD) was -0.0142, and the MAD was 1.1640, thus indicating a high level of fitness. A statistically significant difference (p < 0.05) was also found from the analysis of discrepancies between a current table and the new table used in this study. It is therefore suggested that the new table-with data from actual stands-will contribute to enhancing the accuracy of national and municipal forest statistics and reducing losses caused by imprecise data on available forest resources.

• Journal of Korean Society of Forest Science
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• v.8 no.1
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• pp.11-16
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• 1968

1. A Study was to delineate the correlation relationship growth factors, a) height and clear-length, b) height and circle of breast height, c) height and circle of ground height, d) height and crown length, of phyllostachys reticulata kock and phyllostachys edulis riv, 2. The formula applied to arrive at correlation coefficient according to correlation table, was $e=\frac{1-{\mu}^2}{\sqrt{\Sigma}X^2y^2}$ the formula for average error was $e=0.6745\frac{1-{\mu}^2}{\sqrt{n}}$ 3. The correlation coefficient and average error by each species were as three tables. 4. Area of the sample plot were 0.5~1 acres. 5. Height, clear-length, circle of breast height, circle of ground height and crown-length of bamboos were measured by weise hypsometer and pole.

• Korean Journal of Health Education and Promotion
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• v.19 no.4
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• pp.77-97
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• 2002

Since growth promotion was defined by Koch(1935), many researches like Benholdt and Thomsen(1942) have conducted studies for understanding problem of puberty growth. Growth promotion means that growth is developed in puberty, and several researchers have reported that the more becomes economic growth, the more becomes growth promotion. Thereupon, this study was attempted to find Maximum Growth Age(M.G.A.), as an index of height growth promotion in Korea, which was obtained by longitudinal observations of the same group. Thus, this study can explain the earlier tendency of growth. To investigate domestic changes in M.G.A., M.G.A. was calculated with the results of cross-sectional researchs using 25 representative papers between 1940-1953 including measurements by Lee(1940) and data by Kim(1953) in this study. Based on the research data published between 1940 and 2000, height and M.G.A. of males and females who were born between 1925 and 1983 were gotten by years, and a trend of growth promotion for height in Koreans was suggested by examining study subjects. Findings of this study are as follows; 1. M.G.A. for height decreased both in males and females; for males, 14.28 years in 1940, 14.24 in 1953, 13.86 in 1967, 12.74 in 1985, and 11.71 in 2000; for females, 12.0 in 1940, 11.52 in 1965, 10.00 in 1978 and 9.77 in 2000. 2. Regression equations and standard errors of estimate concerning M.G.A. for height by years were obtained; for males, Y$_1$(M.G.A.) = 17.21 - 0.059X$_1$, S$_{Y1X1}$(standard error of estimate about the regression line) = ${\pm}$0.62; for females, Y$_2$(M.G.A.) = 13.81-0.042X$_2$, S$_{Y2X2}$(standard error of estimate about the regression line) = ${\pm}$0.64 3. As a result of finding correlation between year and M.G.A. r=-0.763 (p<0.001) for male and r=-0.699(p<0.001) for female were obtained 4. From a view that the growth promotion has been continued before 2000, M.G.A. decreased 0.6 years for male and 0.4 for female per 10 years. 5. M.G.A. for height is as shown in Table 2. 6. It is thought that the future trend of growth promotion for height will follow the progress from 1940s to now. It shall be reviewed again after development of coming several years is investigated.

• Journal of the Korean Home Economics Association
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• v.11 no.1
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• pp.14-25
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• 1973

The measurements includings 22 items such as height, weight, body width were carried out for Korean male and female students, one hundred each, from 18 to 24 years old. The correlation coefficient was calculated for every two items. The values are basic for the Clothing construction and the Pattern grading. The results are as follows : 1) The measuring values are as shown in Table 1 and the index are as shown in Table 2. 2) The correlation coefficient of length to length is larger than that of length to girth and that of length to width. The correlation coefficient of girth to girth is larger than girth to length and that of girth to width. The correlation coefficient of width to width does not show remarkable difference from those of others. 3) The correlation coefficient values of weight to lengths, weight to lengths, weight to girths and weight to width are larger. Among these, the correlation coefficient of weight to girths is the largest. 4) The correlation coefficient in general shows almost positive values except a few exception showing negative values. 5) No meaning differences are found between males and females.

• Journal of the Korea Furniture Society
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• v.15 no.2
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• pp.53-62
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• 2004

This study explored the development of wood furniture made of aged Castanea crenata Sieb. et Zucc, which has been largely planted in the southern area since 1960s and has hardly been used as furniture materials. First, the physical properties of the chestnut wood including specific gravity, stiffness, and shrinkage were compared with Zelkova serrata, Acer palmatum Thunb., Fagus crenata var. multinevis, Quercus, Tagayasan, Prunus serrulata var. spontanea, Juglans sinenis, Pteronrpus santalinus, Diospyros ebenum, and Fraxinus rhynchophylla, which have largely been used in manufacturing furniture. The chestnut wood had appropliate physical properties for wood furniture like other furniture woods. A piece of small table 50 cm in width, 50 cm in length and 60 cm in height by the chestnut tree was created for a current interior space. Since the diameter of the chestnut tree planted since 1960s is below around 30 cm, the top plate of the table had to be put together by an end-joint technique using a small strip. Finally, it is expected that this study will create a greate motivation for furniture designers, furniture studios and furniture companies in Korea to use the woods from the aged chestnut tree in developing furniture in the future.

• Journal of Environmental Science International
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• v.23 no.4
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• pp.605-613
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• 2014

In this work, the delay time for groundwater recharge was estimated by comparing simulated recharges by means of SWAT(Soil and Water Assessment Tool) model and WTF(Water Table Fluctuation) method. The delay time for groundwater recharge means that the time when the water from rainfall travelled through vadose zone just after getting out of soil zone bottom. As measuring this delay time is almost impossible, we used to compare the estimated values from modeling(SWAT) and analytic method(WTF). The test site is Hancheon watershed which has 8 groundwater measurement stations. The results show that the altitude has a linear relationship with the estimated delay time values. To validate these results, we conducted corelation analysis between transformed groundwater levels and observed ones. The results showed that computed groundwater levels have good corelation($R^2$=0.97, 0.87, respectively). The estimated delay time would be used for the groundwater behaviour characteristics in vadose zone. As recharge rates vary according to the height, the delay time is thought to be an import variable for the proper groundwater recharge estimation.

• Journal of the Earthquake Engineering Society of Korea
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• v.19 no.4
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• pp.161-171
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• 2015

A series of tests was conducted for full-scale single-pylon asymmetric cable-stayed bridges using a system of multiple shaking tables. The 2-span bridge length was 28 m, and the pylon height was 10.2 m. 4 different base conditions were considered: the fixed condition, RB (rubber bearings), LRB (lead rubber bearings), and HDRB (high damping rubber bearings). Based on investigation of the seismic response, the accelerations and displacements in the axial direction of the isolated bridge were increased compared to non-isolated case. However, the strain of the pylon was decreased, because the major mode of the structure was changed to translation for the axial direction due to the dynamic mass. The response of the cable bridge could differ from the desired response according to the locations and characteristics of the seismic isolator. Therefore, caution is required in the design and prediction in regard to the location and behavior of the seismic isolator.

• Korean Journal of Agricultural Science
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• v.50 no.3
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• pp.469-484
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• 2023

In this study, three types of structures-stepped gabion retaining walls, vertical gabion retaining walls, and parapets-were installed on the dam floor crest to prevent the overflow of deteriorative homogeneous reservoirs. The acceleration response, displacement behavior, and pore water pressure ratio behavior were compared and evaluated using shaking-table model tests. The experimental conditions were set to 0.154 g in consideration of the domestic standard and the seismic acceleration range according to the magnitude of the earthquake, and the input waveform was applied with Pohang, Gongen, and artificial earthquake waves. The acceleration response according to the design ground acceleration increased as the height of the embankment increased, and the observed value were larger in the range of 1.1 to 2.1 times the input acceleration for all structures. The horizontal and vertical displacements exhibited maximum values on the upstream slope, and the embankment was evaluated as stable and included within the allowable range for all waveforms. The settlement ratio considering the similarity law exhibited the least change in the case of the parapet structure. The amplification ratio was 1.1 to 1.5 times in all structures, with the largest observed in the dam crest. The maximum excess pore water pressure ratio was in the range of 0.010 - 0.021, and the liquefaction evaluation standard was within 1.0, which was considered very stable.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.1
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• pp.17-22
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• 2015

A total of CNU 28 hybrids were developed at the CNU Corn Breeding Lab. were evaluated to identify new cultivars in botanical characteristics, fresh yield per 10a and taste qualities. Most of these hybrids were stable in environmental stresses such as lodging, disease and insects. Stem height ranged from 115.0 to 239.3 cm, and ear height ranged from 30.7 to 107.0 cm. The ear height to stem height ratio was showed low than 50% of standard as a stable plant type to lodging. The range of ear length was 14.2 cm to 23.0 cm. Especially, CNU 13H-73 was very longest ear as a 23 cm. The fresh yield per 10a was high in purple of CNU13H-79 hybrid than control hybrid Miheuckchal, and CNU13H-73 in white hybrid was similar Yeonnong check hybrid. The 100-kernel weights in CNU13H-3 and CNU13H-9 hybrids were higher than that of the control hybrid. CNU13H-98 among hybrids had a 100-kernel weight of 20.32 g, which was heavier than that of the control hybrid Daehackchal Gold 1. The average pericarp thickness was $41.4{\mu}m$, CNU13H-46 among hybrids had a very thin pericarp as a $35.5{\mu}m$. The mean sugar content of the used hybrids was 14.95 brix%; CNU13H-73 and CNU13H-55 had higher than Mibak2 as a control hybrid.

• Journal of Korean Society of Forest Science
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• v.25 no.1
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• pp.49-71
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• 1975

The importance of bamboo as raw material for bamboo wares and several kinds of industrial products is highly appreciated at home and abroad. But different kinds of bamboo-bundle systems have been traditionally used in the local areas. There being no reasonable bamboo-bundle system, we have a lot of difficulty in trading bamboo products and executing adrinistmative works. Therefore, a reasonable bamboo-bundle system based on scientific proofs needs to be tested and established for fair trade and administration. This study is carried out to solve the above difficulty with statistical investigation and analysis. The results obtained are as follows. 1. The larger the circles at eye-height become, the more the possibility of the largest internode covering the span between eye-height and 1/4 height increases. 2. The longest internodes are distributed according to a rule without relation to circles at eye-height. 3. The tapering grade of bamboo culms is very high and its form is almost the same without relation to its size. (Form exponent; 0.71-1.05, eye-height form factor; 0.60-0.66, 1/4 becomes, seeing that the circle grade and the percentage of actual volume height form factor; 0.61-0.69). 4. The larger the circles at eye-height are, the lower the percentage of actual volume have negative curve relation to each other. 5. It is considered that the numbers of bamboos bundled in a "Sok" is not decided according to the usefulness of bamboos, judging from the fact that the outputs of bamboo wares per "Sok" in every circle grade are not the same. 6. As the results of the regression analysis, the empirical formulae of several amounts to circles at eye-height and culm length are as follows; Volume, $${\hat{y}}_i=\bar{3}.821874+2.013181log\;C_i+0.839128log\;H_i$$ $$V=0.0066355\;C^{2.013181}\;H^{0.839128}$$ Actual volume, $${\hat{y}}_{ai}=3.915338+0.776549log\;C_i+1.857000log\;H_i$$ $$V_a=0.0082288\;C^{0.776549}\;H^{1.857000}$$ Weight, $$w_i=3.869148+1.936410log\;C_i+0.566904log\;H_i$$ $$W=0.0073986\;G^{1.936410}\;H^{0.565904}$$ 7. Korean Phyllostachys bambusoides Sieb. et Zucc. is almost the same as that of Japan in several amounts, just the same especially in the weight. 8. It is found that the bamboo-bundle systems of Korea and Japan have much closer relation to the weight than other amounts. So It is, therefore, considered that the weight is important factor in deciding bamboo-bundle system. 9. According to the item 8, I should like to propose the appropriate numbers per "Sok" adjusted on the basis of the weight in the Table 18.