• The Journal of the Korean dental association
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• v.19 no.2 s.141
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• pp.167-174
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• 1981

The purpose of this study was observing the annual growth increment in cephalogram. The cephalograms of 29 boys & 23 girls were analized by method of Downs & Steiner, range from 7 to 8 years in Korean children. the results were as follows; 1. The craniofacial complex of Korean children grew downward and fordward. 2. The pronounced linear and angular growth changes were in the upper central incisors and lower central incisors. 3. The SN Plane to Mandibular plane angle was reduced. 4. The SNA and SNB was almost constant in male.

• Proceedings of the KIEE Conference
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• summer
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• pp.73-75
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• 2004

This paper presents the ability and the application of software packages for distribution planning which are DISPLAN(Distribution Planning System) and DLPLAN(Distribution Line Planning System) developed in KEPCO. After calculating size and position of maximum load by administration section for distribution, it forecasts the demand of distribution load considering growth location, increment, new load plan, etc of load by annual. Also it calculates distribution loss, voltage drop using modeled distribution line by you, and support for establishment and enlargement plan of substation and distribution line, decision of most optimal path. And it presents the abstract of used algorithm to develop this system.

• Korean Journal of Agricultural and Forest Meteorology
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• v.13 no.4
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• pp.157-164
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• 2011

Long-term annual water balances are analyzed for two forest catchments located in Gwangneung covered with forests of different types and ages. The water balance trends of the two catchments from 1982 to 2009 are compared to identify the effect of forest growth and thinning on the water balance in a planted coniferous forest catchment. According to the averaged annual precipitation and runoff for the four designated periods from 1982 to 2009, the water balance of the old natural broad-leaved forest catchment (GB) remained relatively unchanged. In contrast, the young planted coniferous forest catchment (GC) showed significant changes in the water balance due to the forest growing and thinning. The results showed that the catchment runoff decreases with increasing tree age whereas the forest thinning results in an increase in catchment runoff. The mean annual runoff from the catchment GC after thinning increased by 1.7 times, compared with the mean annual runoff before forest thinning. The mean annual runoff from the catchment GB was very stable throughout the period. However, such an effect of forest thinning appeared to last only for about 10 year-period, after which the water yield increment in the catchment GC disappeared. It indicates that the proper forest management should be reconsidered at the interval of 10 years to effectively reduce water loss and increase water yield in the planted coniferous forest.

• Journal of Korean Society of Forest Science
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• v.97 no.6
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• pp.605-610
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• 2008

This study was carried out to investigate the short-term (3 years) effect of thinning on aboveground carbon storage for 34-year-old (site 1) and 45-year-old (site 2) Korean pine (Pinus koraiensis Siebold et Zuccarini) plantations with different diameter class and site quality located in Gwangneung experimental forest. Thinning was manually carried out in consideration of basal area in 2004 (site 1 : 30% and 60% of basal area removed and site 2 : 60% of basal area removed). In 2004 and 2007, DBH and tree height were measured to analyze the changes in carbon storage after thinning. In the sites of 60% of basal area removed, although the mean DBH of site 1 was higher than that of site 2, mean annual carbon storage increment in site 2 ($6.5Mg\;C\;ha^{-1}yr^{-1}$) was about 3 times higher than that in site 1 ($2.3Mg\;C\;ha^{-1}yr^{-1}$). The reason for this result was probably due to higher stem density and site quality in site 2 compared to site 1. In site 2, mean annual carbon storage increment in thinned plot ($6.5Mg\;C\;ha^{-1}yr^{-1}$) was about 1.3 times higher than that in control ($5.2Mg\;C\;ha^{-1}yr^{-1}$). The results suggest that the stem density and site quality may be much more related to the aboveground carbon storage compared to diameter class. In addition, it is needed to consider these two factors for determining whether thinning is a feasible management alternative for the increase in aboveground carbon sequestration.

• Journal of Korean Society of Forest Science
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• v.110 no.4
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• pp.648-657
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• 2021

This study was conducted to estimate the volume growth by forest type and major species using the national forest resource inventory and to predict the final age of maturity by deriving the mean annual increment (MAI) and the current annual increment (CAI). We estimated the volume growth using the Chapman-Richards model. In the volume estimation equations by forest type, coniferous forests exhibited the highest growth. According to the estimation formula for each major species, Larix kaempferi will grow the highest among coniferous tree species and Quercus mongolica among broad-leaved tree species. And these estimation formulas showed that the fitness index was generally low, such as 0.32 for L. kaempferi and 0.21 for Quercus variabilis. In the analysis of residual amount, which indicates the applicability of the volume estimation formula, the estimates of the estimation formula tended to be underestimated in about 30 years or more, but most of the residuals were evenly distributed around zero. Therefore, these estimation formulas have no difficulty estimating the volume of actual forest species in Korea. The maximum age attained by calculating MAI was 34 years for P. densiflora, 35 years for L. kaempferi, and 31 years for P. rigida among coniferous tree species. In broad-leaved tree species, we discovered that the maximum age was 32 years for Q. variabilis, 30 years for Q. acutissima, and 29 years for Q. mongolica. We calculated MAI and CAI to detect the point at which these two curves intersected. This point was defined by the maximum volume harvesting age. These results revealed no significant difference between the current standard cutting age in public and private forests recommended by the Korea Forest Service, supporting the reliability of forestry policy data.

• Journal of The Korean Society of Grassland and Forage Science
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• v.10 no.3
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• pp.141-146
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• 1990

Changes in dry matter yield, crude components, nutrients uptake($P_2O_5$, $K_2O$, CaO, MgO) and sulphur containing amino acid(cysteine, methionine) of orchardgrass(Dacty1is glomerata. L) and alfalfa(A4edicago sativa. L) by gypsum application(as sulphur source, 0, 2. 5, 10, 20kg SIlOa) were investigated to understand the effect of sulphur on herbage production in pasture, which was established in 1987 as means of hand broadcasting. The effect of gypsum on dry matter yield at different cutting times during growing seasons has not been found both in orchardgrass and in alfalfa, but in respect to annual total dry matter yield there were increment in herbage yield (P<0.05) of alfalfa at 5, 10, 20kg SIlOa in 1989 and the amounts of sulphur taken up in herbage slightly increased according to the rates of gypsum application. Maximum apparent recovery of sulphur was 7.55% at 2kg SIlOa in orchardgrass and was 17.8% at 5kg S/lOa in alfalfa. There were no any great differences in the content of crude components of both species and this trend was similar with the mineral contents of orchardgrass. But in alfalfa, the amounts of $K_2O$, CaO, and $P_2O_5$ taken up were increased by gypsum application and the increment in the amounts of minerals taken up in herbage at 20kg SIlOa were 14.9 of $K_2O$, 9.1 of CaO, and 2.5kgIlOa of $P_2O_5$ as compared to those of at untreated plot. Cysteine and methionine were not influenced by gypsum applicaton not only in orchardgrass but also cysteine in alfalfa, however, the content of methionine in alfalfa was slightly increased at 2, 5, lOkg SIlOa and at 20kg SIlOa was reverse.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.1
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• pp.9-16
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• 2008

In this study we investigated the effects of the microclimatic conditions on tree growth in different site types for natural deciduous forests in Korea. First, we classified all the sites into 36 types according to their aspect (east, west, south, and north), elevation (higher than 1,000 m, 700$\sim$1,000 m, and lower than 700 m), and topographical conditions (ridge, slope, and valley). For each site type, we measured diameter growth with increment borer, and then estimated periodic annual increment of diameter, height and volume. We applied a topoclimatological technique for estimating microclimatic conditions, and produced monthly climatic estimates from which 17 weather variables (including indices of warmth, coldness, and aridity) were computed for each site type. The periodic annual increments of diameter, height, and volume were then correlated by regression analysis with those weather variables to examine effects of microclimate on tree growth by site type. We found that the correlation of diameter growth by site type was significantly correlated with most weather variables except daily photoperiod. Water condition was the most important factor for the height growth. For volume growth, on the other hand, the conditions such as relatively high temperature and low humidity provided favorable environment. Our regression analysis shows that aridity index is a good predictor for tree growth including diameter, height and volume increments.

• Journal of Korean Society of Forest Science
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• v.99 no.1
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• pp.144-152
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• 2010

This study was conducted to analyze the growth characteristics and aboveground carbon storage for old growth Zelkova serrata artificial forests (site1: age class IX, site2: age class VIII) in Gwangneung Experimental Forest. The trees were classified by crown classes for analyzing forest stand structure. The growth characteristics were analized through ringwidth increment by crown classes and stem analysis of dominant trees. There were a wide range of DBH (site1: 8~62 cm, site2: 14~40 cm) and height (site1: 8~26 m, site2: 12~26 m) distributions and revealed different growth characteristics by crown classes in both sites. The mean annual increment (MAI) of ringwidth for the last 5 years of dominant trees for site1 (3.3 mm) was higher than MAI of ringwidth of total growth period (2.3 mm) and MAI of ringwidth for the last 5 years of dominant trees for site2 (2.2 mm) was equal to MAI of ringwidth of total growth period (2.2 mm). Also, the growth increment of ringwidth by crown classes had significant differences between dominant tree and the others crown classes (p<0.01) in both sites. As a results of stem analysis of dominant trees in both sites, there were similar to their volume between site1 (1.106 $m^3$) and site2 (1.035 $m^3$). In spite of old age, the annual increment of volume has been increasing steadily until recent year. Meanwhile, total aboveground carbon storage of site1 (65.6 Mg C $ha^{-1}$) was higher than that of site2 (56.1 Mg C $ha^{-1}$). The proportion of dominant and co-dominant trees to total aboveground carbon storage was more than 90% and the greatest individual aboveground carbon storage by crown classes was dominant tree in all both sites. However, individual aboveground carbon storage of dominant tree in site1 had 0.054 Mg C $tree^{-1}$ more than site2 owing to the differences from average DBH of dominant trees by sites. We think that these results will contribute to the forest practice for Zelkova serrata artificial forests as a basic information.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.1
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• pp.1-11
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• 2002

This study was conducted to reveal the effects of local climatic conditions on the early growth of Korean white pine progeny test stands. For this, stand variables such as mean DBH, mean height, basal area per hectare, and volume per hectare by stand age and locality were first measured and summarized for each stand. Based on these statistics, annual increments for 10 years from stand age 10 to 20 were calculated for each of stand variables. The effects of local climatic conditions as one of environmental factors on the growth were then analyzed by both a topoclimatological method and a spatial statistical technique. From yearly climatic estimates,30 climatic indices which affect the tree growth were computed for each of the progeny test stand. The annual increments were then correlated with and regressed on the climatic indices to examine effects of local climatic conditions on the growth. Gapyung area provided the best conditions for the early growth of Korean white pine and Kwangju area ranked second. On the other hand, the growth pattern in Youngdong ranked last overall as expected. It is also found that the local growth patterns of Korean white pine in juvenile stage were affected by typical weather conditions. The conditions such as low temperature and high relative humidity provide favor environment for the early growth of Korean white pine. Especially, it was concluded that the low temperature is a main factor influencing the early growth of Korean white pine based on the results of correlation analysis and regression equations developed far the prediction of annual increments of stand variables.

• Journal of Korean Society of Forest Science
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• v.79 no.1
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• pp.1-15
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• 1990

In this study the stem analysis program, which can be operated with personal computer was developed to reduce time and cost of calculation, and to increase accuracy of analysis. The stem analysis method used in this program was compared with other methods. The results obtained were as follows : The value, 1/100mm measured from the latest annual ring measurement machine (Jahrringme${\beta}$geraete Johan Type II) was automatically inputed to the computer and saved into given file name. Turbo Pascal program was written to do this. The measured data was analyzed by stem analysis calculation program written by Fortran-77. Volume and height increments were approximated by spline function, and diameter of the stem disk was calculated by quadratic mean method. The increment values calculated by the programs were printed annually and in every five-year. Stem analysis diagram and several increment graphs were also easily printed. The result compared between those analysis methods showed that quadratic mean could reduce the error caused from eccentric pith. When the stem taper curve method, approximated by spline function, was used in the calculation of tree height and volume, increments would be more exactly calculated.