• Journal of Ecology and Environment
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• v.37 no.4
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• pp.177-184
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• 2014

This study was conducted to develop allometric equations and to determine the stem density and biomass expansion factor (BEF) for the estimation of the aboveground and belowground biomass of Cryptomeria japonica in Jeju Island, Korea. A total of 18 trees were harvested from the 40-year-old C. japonica stands in Hannam experimental forest, Jeju Island. The mean biomass of the C. japonica was $50.4Mg\;ha^{-1}$ in stem wood, $23.1Mg\;ha^{-1}$ in root, $9.6Mg\;ha^{-1}$ in branch, $4.6Mg\;ha^{-1}$ in needle and $4.3Mg\;ha^{-1}$ in stem bark. The diameter at breast height (DBH) was selected as independent variable for the development of allometric equations. To evaluate the performance of these equations, coefficient of determination ($R^2$) and root mean square error (RMSE) were used and results of the evaluation showed that $R^2$ ranged from 71% (root biomass equation) to 96% (aboveground biomass equation) and the RMSE ranged from 0.10 (aboveground biomass equation) to 0.33 (root biomass equation). The mean stem density of C. japonica was $0.37g\;cm^{-3}$ and the mean aboveground BEF was $1.28g\;g^{-1}$. Furthermore, the ratio of the root biomass to aboveground biomass was 0.32.

• Journal of Korean Society of Forest Science
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• v.24 no.1
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• pp.53-61
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• 1974

Pine forests existing in Hong-do island were examined as regarding such characteristics, tree form, needle length, branch diameter, bark colors, ratio of summer wood to springwood, location and number of resin canal and other measurements. Hong-do island, located the furthest west part of Korea, suports only Pinus densiflora but very few Pinus thunbergii, in fact the present authors could not find any black pine individuals at all through investigation. Checking 14 individual trees of red pine, more than age of 20, of the genetic contamination by black pine, in a certain degree, exist. Here, a very dense foliage type and a very sparse foliage type tree of red pine growing nearby was examined and the unique fact was that each of those type has only one (average number 1.3) accessory resin canal, while other trees have three as minimum or more. The present authors thought this island had not been covered by any Pinus thunbergii but by Pinus densiflora. It was thought that Pinus thunbergii stands grown along the sea-coast of Korean Peninsula are pollen donors to this island.

• Journal of Korean Society of Forest Science
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• v.84 no.2
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• pp.186-197
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• 1995

Site-specific allometric equations relating aboveground tree component biomass and leaf area to tree diameter, basal area, sapwood cross-sectional area and sapwood volume were developed using the destructive harvesting method for Pinus rigida Mill., Larix leptolepis Gordon, and Quercus serrata Thunb. stands in Yangpyeong, Kyonggi Province. There were significantly strong correlations between aboveground tree component biomass or leaf area and diameter at breast height (DBH), basal area, sapwood area and sapwood volume. For a similar diameter tree, the three species had a similar stem wood biomass. However, carbon allocation patterns to stem bark, foliage, branch and total aboveground biomass differed among the three species. Specific leaf area and the ratio of leaf area to sapwood cross-sectional area of the three species were significantly different. Allometric equations seemed To be related to leaf habit or leaf longevity. To elucidate the effect of leaf habit or leaf longevity on allometry and canopy characteristics clearly, more intensive studies are needed.

• Journal of Animal Science and Technology
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• v.58 no.2
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• pp.8.1-8.14
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• 2016

In this research data representing 72,946 primiparous cows from 724 herds with 638,063 total test day records calved between 2001 and 2011. These data were analysed to determine the effect of age at first and season of calving on parameters of the Wood lactation curve. Also, genetic trend of the lactation curve parameters in different calving years were evaluated. The results indicate that the highest rate of atypical lactation curve was related to cows that calved in summer (28.05 %). The maximum phenotypic relationship between initial milk yield and total 305-d milk yield was observed in cows calved in spring (0.40). The role of peak yield is more than peak time on 305-d total milk yield in primiparous Holstein. One month increase in age at first calving from 18 to 26 month raised 305-d milk yield by around 138 kg and from 27 to 32 month decreased by 61 kg. The persistency of lactation between 101 and 200 days is higher than that of 201-305 days. Our results indicate that the shape of lactation curve is largely dependent on the season of calving (higher level of milk production in cows which calved in autumn and winter). The heritabilities of parameters of lactation curve and persistency measures were low. The genetic trends for peak time, peak yield and 305-d milk yields were positive and estimated to be 0.019, 0.021 and 8.13 kg/year respectively. So the range from 24 to 26.5 month of calving is the optimum calving time in primiparous Holstein for maximizing 305-d milk yield.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.44 no.1
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• pp.18-24
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• 2018

Objectives: Foreign bodies (FBs) account for 3.8% of all pathologies of the head and neck region, and approximately one third of them are missed on initial examination. Thus, FBs represent diagnostic challenges to maxillofacial surgeons, rendering it necessary to employ an appropriate imaging modality in suspected cases. Materials and Methods: In this cross-sectional study, five different materials, including wood, metal, glass, tooth and stone, were prepared in three sizes (0.5, 1, and 2 mm) and placed in three locations (soft tissue, air-filled space and bone surface) within a sheep's head (one day after death) and scanned by panoramic radiography, cone-beam computed tomography (CBCT), and ultrasonography (US) devices. The images were reviewed, and accuracy of the detection modalities was recorded. The data were analyzed statistically using the Kruskal-Wallis, Mann-Whitney U-test, Friedman, Wilcoxon signed-rank and kappa tests (P<0.05). Results: CBCT was more accurate in detection of FBs than panoramic radiography and US (P<0.001). Metal was the most visible FB in all of modalities. US was the most accurate technique for detecting wooden materials, and CBCT was the best modality for detecting all other materials, regardless of size or location (P<0.05). The detection accuracy of US was greater in soft tissue, while both CBCT and panoramic radiography had minimal accuracy in detection of FBs in soft tissue. Conclusion: CBCT was the most accurate detection modality for all the sizes, locations and compositions of FBs, except for the wooden materials. Therefore, we recommend CBCT as the gold standard of imaging for detecting FBs in the maxillofacial region.

• Industry Promotion Research
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• v.9 no.1
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• pp.203-212
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• 2024

The purpose of this study is to examine the validity of Hidden Stems (支藏干) in the Four Pillars of Destiny with regard to the use of human governance periods in the hidden stems (人元用事). First, there is a theory of assigning period of governance for designated constituents (司令論) in the Hidden Stems of the Earthly Branch. Second, there is a theory that determines the structure of the Four Pillars by the Exposed Constituent from the Hidden Stems (透出論) in the Month Earthly Branch. Since these two theories conflict with each other and cause confusions, this study examined the theory of Hidden Stems in the Four Pillars Classics and examined the historical development of governance period for constituent hidden stems and their validity. The results of the study are as follows: Firstly, the number of dates assigned to respective constituents does not correspond to the calendarical principle, and the assignment of the governance dates for each constituent does not correspond to the principles proposed in ancient books of Four Pillars. Second, though it is said in the Classics that 72 days are equally assigned to each of the Five Elements, actual distributed days for the five elements was 65 days for Wood, 55 days for Fire, 100 days for Earth, 65 days for Metal, and 65 days for Water. Third, though it is said that 7 days should be designated to Yang Earth Mu for the months of Tiger 寅, Monkey, Snake, and Pig, it is logically more legitimate to assign those days to Yin Earth Ki since the month before Tiger is Ox, and the month before Monkey is Goat. Lastly, rationale behind assigning Ki Earth only to Horse Oh as constituting Hidden Stem while disregarding months of Rat, Rabbit, and Rooster is considered not reasonable. Looking at these results comprehensively, it is concluded that the Exposed Constituent theory is logically more appropriate than Assigned Governance theory.

• Journal of Sericultural and Entomological Science
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• v.38 no.2
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• pp.93-99
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• 1996

By treatment(dropping) of 0.1~0.4% colchicine solution on the sprouts of winter buds of hard wood cutting slips for 4~5 days, two lines of artificial autotetraploids from Yongchonppong and one line from Yeongbyonppong were bred and the important cultivative characteristics of those new lines were as follows. The greentip sprouting stage of the new bred lines in spring season is later than the parental varieties by two days, but growth speed of the new lines after sprouting was faster than that of the parental varieties reaching the same level development with the parental varieties at the fifth leaf sprouting stage to be mid varieties same as the origins. The leaf shape of the new bred lines was wide round and the petioloes were long and thick. The thickness of leaf was thicker than the parental varieties by 17-33% and single leaf weight was heavy. The leaf area weight increased by 21-31% and the content of chlorophyll was also higher by 11-33%. With all the characteristics, the new breds produced good quality of leaves. The length and number of branches were shorter and less, respectively, than the parental varieties, but the internode length was either same or longer than the parents. Looking at the characteristics, the constitution of shoots was slightly inferior to the parental varieties. The cold hardness expressed by the death top rate of Sawonppong 23 and Sawonppong 24 was same level as that of Yongchonppong, but Sawonppong 25 was stronger than Yeongbyonppong in it with a high infection rate of dwarf disease. The productivity was lower than the parental varieties, but young shoot rate to shoot and branch and the ratio of leaf to young shoot were higher than the parental varieties. The fertility of Sawonppong 23 and Sawonppong 24 was comparatively high with 62% of cross success, but that of Sawonppong 25 was low with 23.9% of cross success.

• Journal of Korean Society of Forest Science
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• v.95 no.4
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• pp.393-397
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• 2006

Thuja koraiensis Nak. is a short and creeping evergreen shrub which reaches about 3 m in height and only occurs in the northeast China and in high mountains over the Korea. It's designated as a rare and endangered tree species in Korea and DD (data deficient) in Red List Category & Criteria of IUCN. This study was carried out to develop the propagation technique by cutting for conservation of genetic resources of T. koraiensis. The rooting responses of branch cuttings, obtained from hard (May) and semi-hard wood shots (August) to three plant growth regulators (PGRs), namely, IAA, IBA, and NAA applied at various concentrations (0, 100, 500, 1000, 2000, and 3000 mg/l) were examined in sand and mixed soil media. Percentage of rooting showed significant difference between cutting time, among kinds and among concentration of PGRs. The optimum cutting time was April to May in hardwood cutting. The application of IAA 1000 mg/l and NAA 500mg/l were effective in callus formation and rooting of cutting. Relatively, rooting of cutting of the control taken in May was above 93%.

• Korean Journal of Plant Resources
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• v.23 no.4
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• pp.368-373
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• 2010

Juniperus chinensis var. sargentii Henry is a short and creeping evergreen shrub which reaches about 60 cm in height and only occurs in the northeast Asia and in the top of high mountains over the Korea. The Korea Forest Service protects it strictly by law since J. chinensis var. sargentii is an eccentric plant and possibly may be exterminated soon in Korea. This study was carried out to develop the propagation technique by cutting for conservation of genetic resources of J. chinensis var. sargentii. The rooting responses of branch cuttings, obtained from hard(May) and semi-hard wood shoots (August) to four growth regulators, namely, IAA, IBA, NAA and Rooton(exceptionally powder method) applied at various concentrations(0, 100, 200, 500, 1000 and 2000 $mgL^{-1}$) were examined in mixed soil media. Rooting rate showed significant difference between cutting times, among kinds and among concentrations of growth regulators. The optimum cutting time was April to May in hardwood cutting. The application of IBA 1000 $mgL^{-1}$(rooting rate : 36.4%) was most effective in callus formation and rooting of cutting. Relatively, rooting of cutting of the control taken in May was 30.4%. Root characteristics such as number, length and diameter of root were not significantly affected by kinds and concentrations of growth regulators in hardwood cutting.

• Journal of Korean Society of Forest Science
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• v.34 no.1
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• pp.1-14
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• 1977

These studies were carried out to know the variation of morphological tree forms, needles, cotyledons, seed characters and top height growth of seedlings of Pinus koraiensis S. et Z. by populations in Mt. Jiri. The results are summarized as follows: 1. It was observed that the characteristics of length, needles of serration density of needles, percentage of full seeds length, of seeds, thickness, of seeds length of cotyledons, width of cotyledon, numbers of the stomata line in cotyledons and the top height growth of seedlings were significantly different in individual trees and populations. 2. The characteristics of branch angle specific gravity of wood and resin canal numbers of cotyledons were significantly different in populations. 3. It was that the characteristics of numbers of stomata line, width, of seeds weight, of seeds serration density of cotyledons, numbers of cotyledons were significantly different in individuals. 4. The resin canals of needles showed three principle resin canals in individual trees and population, and the coefficients of variation were not shown in individual trees and populations. Stem forms showed to be a straight form with all populations. 5. The characteristics of cotyledons had generally higher tendency than the characteristics of needles in comparison with coefficience of variation.