• Journal of Korean Society of Forest Science
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• v.102 no.4
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• pp.543-549
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• 2013

This study was conducted to evaluate age-specific and generalized allometric equations and biomass expansion factors (BEFs) for each tree component across three age-sequence stands (35-year-old, 51-year-old, 62-year-old) of black pine (Pinus thunbergii Parl.) in Jinju, located in the western part of Gyeongnam province, Korea. Biomass in each tree component, i.e. foliage, branch, and stem, was quantified by destructive tree harvesting. Allometric regression equations were significant (P<0.05) with diameter at breast height (DBH) or combination of DBH and height ($DBH^2H$) accounting for 55-98% of the variation (as indicated by coefficients of determination, $R^2$) in aboveground biomass except for foliage biomass of the 62-year-old stand. Generalized allometric equations can be used to estimate the biomass of black pine stands because the slopes of age-specific equations over 35-year-old stands were not significantly different by the age-sequence. The stem density and biomass expansion factor (BEFs) were not significantly different (P>0.05) from different stand ages and ranged from 0.45 to $0.51gcm^{-3}$, and from 1.32 to 1.38, respectively. The results indicate that allometric equations, stem density and aboveground BEFs in the matured black pine over 35-year-old are little influenced by different stand ages.

• Journal of Nutrition and Health
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• v.7 no.3
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• pp.27-44
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• 1974

A general survey of 82 perschool children and 473 school children (from 1st to 3rd grade) residing in the Dongnae area of Shindong Myun, choonseoung Gun, Kangwon Province was conducted from June 12 to 21, 1973, to obtain information concerning nutritional status, especially the protein and iron nutrition of preschool and school children in a rural area of Korea. A sample of 58 children 2 to 9 years old was selected from these 555 children for hematological, biochemical and parasitological tests. The results of these tests are presented below, 1) Both the mean body height and mean body weight of these children were higher and heavier than the averages in the Korean Physical Standards. About 39 per cent were above the 90 th percentile of the Korean Physical Standards of height and 35 per cent were above the 90th percentile of the Korean Physical Standards of weight. 2) The rate of infestation by helminthes was 67.6 per cent and there were no cases of hookworm infestation Among the ascaris-infected children, 61.6 per cent fell within an Ascaris E.P.G. count range of $501{\sim}2,000$. This was considered a rather mild intensify of ascaris infection. Nutrient loss due to helminthes was also estimated to be low. 3) The mean hemoglobin level was 11.3gm% $({\pm}0.94)$, and 68.4 per cent of the children were anemic (less than 11gm% among those 5 years old or less, less than l2gm% among those 6 years old or more). The average hematocrit value was 36.1% $({\pm}2.36)$, and only 3.5 per cent showed more than 34% on the M.C.H.C. test. These results showed that the incidence of anemia, in these rural children was high, and that in general it displayed hypochromic characteristics. 4) The average serum iron level was $78.2{\mu}g%$\;({\pm}29.8). The Proportion of the children showing less than $50{\mu}g% in the serum iron level was 5.6 per cent, while 41.8 percent revealed $450{\mu}g% or more in the TIBC determination. Transferrin saturation was below 15% in 71.4 percent of the preschool children, and in 28.6 percent of the school children. Those who had a serum iron level of $50{\mu}g% or less and a TIBC of more than $450{\mu}g% constituted 11.9 percent of the children examined. From these results, it was concluded that especially preschool children were low in iron nutrition, and that most of the anemia might be iron-deficiency anemia. 5) The mean values of total serum protein and albumin were 6.98gm% and 4.99gm% respectively. Especially in serum albumin, all children stowed more than 4 gm%. 6) The mean urinary urea nitrogen Per creatinine ratio was 11.5 $({\pm}4.2)$, and 21.8 percent had a ratio of more than 15. Considering these results, it was suggested that protein nutrition in these children was relatively good.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.5
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• pp.421-427
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• 2013

In general, it can be assumed that the tropospheric effect are removed through double-differencing technique in short-baseline GPS data processing. This means that the high-accuracy positioning can be obtained because various error sources can be eliminated and the number of unknown can be decreased in the adjustment computation procedure. As a consequence, short-baseline data processing is widely used in the fields such as deformation monitoring which require precise positioning. However, short-baseline data processing is limited to achieve high positioning accuracy when the height difference between the reference and the rover station is significant. In this study, the effects of tropospheric delays on the determination of short-baseline is analyzed, which depends on the orientation of baseline. The GPS measurements which include tropospheric effect and measurement noises are generated by simulation, and then rover coordinates are computed by short-baseline data processing technique. The residuals of rover coordinates are analyzed to interpret the tropospheric effect on the positioning. The results show that the magnitudes of the biases in the coordinate residuals increase as the baseline length gets longer. The increasing rate is computed as 0.07cm per meter in baseline length. Therefore, the tropospheric effects should be carefully considered in short-baseline data processing when the significant height difference between the reference and rover is observed.

• Fisheries and Aquatic Sciences
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• v.1 no.1
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• pp.82-93
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• 1998

Monthly changes of the gonad follicle index (GFI), reproductive cycle, egg-diameter composition, first sexual maturity of the Pacific oyster, Crassostrea gigas, were studied based on the samples which have been collected from the intertidal zone of Poryong west coast of Korea, from January to December, 1996. C. gigas, is dioecious, while a few individuals are alternatively hermaphroditic. Monthly variation of gonad follicle index (GFI) used for determination of spawning period, coincided with the reproductive cycle. GFI increased from April when seawater temperatures gradually increased and reached the maximum in May. And then, GFI sharply decreased from June to September due to spawning. Reproductive cycle of this species can be divided into five successive stages: in females, early active stage (March to April), late active stage (April to May), ripe stage (May to August), partially spawned stage (June to September) and spent/inactive stage (September to February); in males, early active stage (February to March), late active stage (April to May), ripe stage (May to September), partially spawned stage (June to September) and spent/ inactive stage (September to February). The diameter of fully mature eggs are approximately 50um. Spawning occurred from June to September, and two spawning peaks were observed in June and August when the seawater temperature was above $20^{\circ}C$. Percentages of the first sexual maturity of males of 20.1-25.0 mm in shell height were over $50\%$, while those of females of 25.1-30.0 mm in shell height were over $50\%$. All the males of > 30.1 mm and all the females of ^gt; 35.1 mm completed their first sexual maturity. The results suggest that C. gigas has a protandry phenomenon. Sex ratios of 919 oysters observed were 453 females $(49.29\%)$, 429 males $(46.68\%)$, 16 hermaphrodites $(1.74\%)$, and 21 indeterminate individuals $(2.29\%)$. In age class I, sex ratio of males were $64.00\%$, thus, a higher percentage than that of females. It was noted that $64.00\%$ of the young males (age class I) were more functional than females in age class I, but 2-3 year-old oysters showed higher percentage of females. Percentages of hemaphrodites in 2-3 year classes were relatively higher than those in other year classes. Histological pattern of hermaphrodites can be divided into two types: Type I (hermaphrodite having a number of newly formed developing oocytes on the oogenic tissues within a degenerating spermatogenic follicle after discharge of numerous spermatozoa) and Type II (hermaphrodite having two separate follicles in the same gonad).

• Journal of Korean Neurosurgical Society
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• v.56 no.1
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• pp.5-10
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• 2014

Objective : When the pedicle screw insertion technique is failed or not applicable, C7 intralaminar screw insertion method has been used as an alternative or salvage fixation method recently. However, profound understanding of anatomy is required for safe application of the bilaterally crossing laminar screw at C7 in clinic. In this cadaveric study, we evaluated the anatomic feasibility of the bilateral crossing intralaminar screw insertion and especially focused on determination of proper screw entry point. Methods : The C7 vertebrae from 18 adult specimens were studied. Morphometric measurements of the mid-laminar height, the minimum laminar thickness, the maximal screw length, and spino-laminar angle were performed and cross-sectioned vertically at the screw entry point (spino-laminar junction). The sectioned surface was equally divided into 3 parts and maximal thickness and surface area of the parts were measured. All measurements were obtained bilaterally. Results : The mean mid-laminar height was 13.7 mm, mean minimal laminar thickness was 6.6 mm, mean maximal screw length was 24.6 mm, and mean spinolaminar angle was $50.8{\pm}4.7^{\circ}$. Based on the measured laminar thickness, the feasibility of 3.5 mm diameter intralaminar screw application was 83.3% (30 sides laminae out of total 36) when assuming a tolerance of 1 mm on each side. Cross-sectional measurement results showed that the mean maximal thickness of upper, middle, and lower thirds was 5.0 mm, 7.5 mm, and 7.3 mm, respectively, and mean surface area for each part was $21.2mm^2$, $46.8mm^2$, and $34.7mm^2$, respectively. Fourteen (38.9%) sides of laminae would be feasible for 3.5 mm intralaminar screw insertion when upper thirds of C7 spino-laminar junction is the screw entry point. In case of middle and lower thirds of C7 spino-laminar junction, 32 (88.9%) and 28 (77.8%) sides of laminae were feasible for 3.5 mm screw insertion, respectively. Conclusion : The vertical cross-sectioned area of middle thirds at C7 spinolaminar junction was the largest area and 3.5 mm screw can be accommodated with 77.8 % of feasibility when lower thirds were the screw entry point. Thus, selection of middle and lower thirds for each side of screw entry point in spino-laminar junction would be the safest way to place bilateral crossing laminar screw within the entire lamina. This anatomic study result will help surgeons to place the screw safely and accurately.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.13 no.2
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• pp.177-185
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• 1995

Gravity anomalies were recovered on a $5'\times{5'}$grid using the sea surface height data obtained from the combination of Geosat, ERS-1, Topex/Poseidon altimeter data around Korean Peninsula bounded by latitude between $30^\circ{N}\;and\;50^\circ{N}$ and longitude $120^\circ{E}\;to\;140^\circ{E.}$ In order to recover the gravity anomalies from SSH(Sea Surface Height), inverse FFT technique was applied. The estimated gravity anomalies were compared with gravity anomalies measured by shipboard around Korean Peninsula. In comparison with the differences of gravity anomaly between measured data and altimeter data, the mean and the standard deviation were found to be -0.51 mGal and 13.48 mGal, respectively. In case of comparison between the measured data and the OSU91A geopotential model, the mean and the standard deviation were found to be 11.93 mGal and 19.19 mGal, respectively. The comparison of gravity anomalies obtained from the OSU91A geopotential model and the altimeter data was carried out. The results were mean of 5.30 meal and standard deviation of 19.62 mGal. From the results, we could be concluded that the gravity anomalies computed from the altimeter data is used to the geoid computation instead of the measured data.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.3
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• pp.135-142
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• 2015

Floating offshore structures should be designed by considering the most extreme environmental loadings which may be encountered in their design life. The most severe loading on a wave-offshore wind hybrid power generation system is wave loads. The principal parameters of wave loads are wave length, wave height and wave direction. The wave loads have different effects on the structural behavior characteristic depending on the combination of wave parameters. Therefore, the process of investigation for critical loads based on the individual wave loading parameter is need. Namely, the equivalent design wave should be derived by finding the wave condition which generates the maximum stress in entire wave conditions. Through a series of analysis, an equivalent regular wave height can be obtained which generates the same amount of the hydrodynamic loads as calculated in the response analysis. The aim of this study is the determination of equivalent design wave regarding to characteristic global hydrodynamic responses for wave-offshore wind hybrid power generation system. It will be utilized in the global structural response analysis subjected to selected design waves and this study also includes an application of global structural analysis.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2D
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• pp.323-334
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• 2011

In this study, we performed the residual geoid modeling using the FFT and LSC methods in context of application of R-R (Remove and Restore) technique as a general technique for gravimetric geoid model in order to propose the effective way of geoid determination in Korea. For this, a number of data compiled for residual geoid modeling by the multi-band spherical FFT method with Stoke's formula and LSC method as known as statistical method. The geometric geoidal heights obtained from 503 GPS/Levelling data were used for inducing the various elements and proper computation process which should be considered for improving the accuracy of residual geoid modeling. Finally, we statistically compared the results of residual geoid heights between FFT and LSC methods and reviewed then the proper way of residual geoid modeling to the region of Korea. As the results of comparison, LSC method is not suitable for residual geoid modeling in Korea due to the noise and lack of gravity observations and the effects of local characteristics, while FFT method by applying Stokes' integral with proper cap size and modified kernel which provides the better accuracy of residual geoid heights up to 10 cm more than those of LSC method.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.3
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• pp.168-175
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• 2021

The optimal determination of seeding rate is critical to minimizing uncertainties about the large variations observed in forage quality and productivity when alfalfa is cultivated under different geographical areas and growing conditions. The objective of this investigation was to provide information about the proper seeding rate according to harvest timing for alfalfa cultivation in the Northern regions of Korea. Alfalfa was sown in September 2018 at a seeding rate of 20, 30 or 40 kg/ha and harvested four times in 2019: May 3, July 2, September 11, and October 13. Regardless of seeding rate, alfalfa plant height was longest at the third harvest (113 cm) and the shortest in the last annual harvest (43.8 cm). However, seeding rate had no effect on alfalfa plant height at any harvest. Forage relative feed value was increased in the first cutting but decreased in the third cuttings as seeding rate increased. However, seeding rate had slight effect on alfalfa forage quality components at the second and fourth cuttings. Total annual DM and crude protein production (in 4 harvests) was greater at higher seeding rates. Plots seeded at a rate of 40 kg/ha produced on average 1,257 and 2,620 kg/ha more forage (DM basis) than those seeded at a rate of 30 or 20 kg/ha, respectively. Forage DM production at the first, second, third, and fourth harvests accounted for 36.1, 24.0, 27.1, and 12.8 % of total annual DM production, respectively. Overall, small differences were seen when alfalfa seeding rate was different but maximum forage DM production (in four harvests) was detected when seeding rate was 40 kg/ha. These data could be useful to the alfalfa growers by allowing them to make more accurate trade-offs between seed price and the expected magnitude of forage yield gains in order to select the best seeding rate.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.2
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• pp.108-117
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• 2011

In drafting the standards on changes in current conditions, the height or the number of stories is applied in a restrictive manner by limiting to securing the distance to vertical surface for cultural properties within the influence investigation area, but this is expected to have a negative impact on the surrounding sceneries as well as results in the dwarfing phenomenon for precious cultural properties. That is, the preparation for supplementing the insufficient objectivity that is likely to take place during the process of drafting the standards on changes in current conditions. Thus the author attempts to suggest the analytic method for the decision making related to objective and reasonable determination and regulation of the changes in current conditions through computer based simulation work that considers the cultural properties and surrounding environments under investigation. In order to achieve such research objectives, the author reviewed the subject sites where the cultural property dwarfing phenomenon was expected to occur in case of the permission for the changes in current conditions or where the impact of natural landscape and natural feature on the earth is less than architectural building or artificial structure or where the new policy program is likely to be adopted due to incomplete establishment of current condition change standard within influence investigation area, among other cultural properties with architectural building or artificial structure nearby located in Cheonan city and then selected Cheonansaji Dangganjiju(flag poles) and Jiksanhyun Gwana(government office). The author then undertook the quantitative visibility analysis in order to determine the comprehensive prospect rights for the cultural properties and surrounding environments concerned.