• Journal of Korean Society of Forest Science
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• v.70 no.1
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• pp.91-102
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• 1985

Growth and biomass production of natural stands of Quercus variabilis in relation to tree density were studied to obtain basic guide lines for future tending operation. Two natural stands of Quercus variabilis located at 900m (A stand: 6,600trees/ha, $15.84m^2/ha$, $\frac{19}{17-20}$) and 800m (B stand: 4,300trees/ha, $16.65m^2/ha$, $\frac{20}{17-21}$) elevation in Sancheong, Kyongnam Province were selected for the comparative study and following results were obtained through a sample plot method. After diameter of individual trees in the sample plots was measured, twelve average trees from each diameter class were cut felled to measure dry weight of $W_S$, $W_B$, $W_L$, $W_{Ba}$, and standing biomass and biomass production rates by a allometrior regressions related to $D^2H$. Vertical distribution of leaves along the stems indicated that photosynthesis was carried out 2.2m above the ground in Stand A and 1.2m in Stand B. Maximum photosynthesis was located 4.2m and 6.2m above the ground in Stand A and B, respectively. Leaf area index was 4.25ha/ha for Stand A, and 3.89ha/ha for Stand B. Above-ground standing biomass was 49.51 ton/ha for Stand A and 59.20 ton/ha and net annual production was 6.75 ton/ha/yr. for Stand A and 8.99 ton/ha/yr. for Stand B. The ratio of net annual production to standing biomass was 17.5% for Stand A and 16.7% for Stand B. Net assimilation rate was 2.75kg/kg/yr. for Stand A and 3.58kg/kg/yr. for Stand B. Stem wood production rate was 1.46kg/kg/yr. for Stand A and 2.09kg/kg/yr. for Stand B. Bark production rate was 0.60 kg/kg/yr. for Stand A and 0.34kg/kg/yr. for Stand B. Above data indicated that Stand B utilized growing spaces and sites more efficiently than Stand A. It is concluded chat productivity of natural stands of Quercus variabilis can be enhanced through optimization of basal areas and number of tree per hectare and that sound management of natural oak stands should be based on systematic sampling of the area for periodic productivity estimation.

• Journal of the Korean Society of Radiology
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• v.10 no.5
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• pp.327-335
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• 2016

The study is enforce to study image quality evaluation of condition provide the IEC and combination of clinical conditions each quality of radiation that image quality to assess the conditions provided to IEC in the clinical environment to conduct image quality assessment of the digital radiography system in the detector have environmental limits. First, image quality evaluation was evaluated by measuring the MTF, NPS using four quality of radiation and Using MCNPX simulation lastly DQE make a image quality evaluation after calculating the particle fluence to analyze spectrum quality of radiation. Second, Using MCNPX simulation of four quality of radiation was evaluated absorbed dose rate about electronic 1 per unit air, water, muscle, bone by using Radiation flux density and energy, mass-energy absorption coefficient of matter. Results of evaluation of image quality, MTF of four quality of radiation was satisfied diagnosis frequency domain 1.0 ~ 3.0 lp/mm of general X-ray that indicated 1.13 ~ 2.91 lp/mm spatial frequency. The NPS has added filter, spatial frequency 0.5 lp/mm at standard NPS showed a tendency to decrease after increase. Unused added filter, spatial frequency 0.5 lp/mm at standard NPS showed a certain NPS result value after decrease. DQE in 70 kVp / unuesd added filter(21 mm Al) / SID 150 cm that patial frequency 1.5 lp/mm at standard showed a tendency to decrease after certain value showed. Patial frequency in the rest quality of radiation was showed a tendency to decrease after increase. Results of evaluation of absorbed dose, air < water < muscle < bone in the order showed a tendency to increase. Based on the results of this study provide to basic data that present for the image quality evaluation method of a digital radiation imaging system in various the clinical condition.

• Journal of dental hygiene science
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• v.15 no.4
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• pp.445-456
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• 2015

The aim of this study was to identify an effective control method of metabolic syndrome (MS) and oral diseases by investigating relationship between of MS and periodontal disease, tooth loss of the adult men and woman. We analyzed and concluded as follows, using a nationwide representative sample, in 8,225 middle senior citizens based on raw data of the 5th National Nutrition Survey in 2010, 2012. The data were analyzed by descriptive statistics, chi-squared test, and logistic regression using SAS ver. 9.2 program. The results are as follows, for correlation of metabolic component to periodontal disease, it was found that in men, the periodontal disease odds ratio of the group with abnormal fasting blood glucose increased 1.27 fold (95% confidence interval [CI], 1.04~1.54), and in woman, the odds ratios of the group with abnormal high density lipoprotein cholesterol increased 1.45 fold (95% CI, 1.22~1.72) and the odds ratio of the group with abnormal obesity increased 1.44 fold (95% CI, 1.17~1.77). For correlation of MS to periodontal disease, it was found that the odds ratio of periodontal disease in the woman at-risk group increased 1.55 fold (95% CI, 1.19~2.01) and that of the group with MS increased 2.25 fold (95% CI, 1.68~3.02). For correlation of woman's metabolic component to missing teeth, it was found that the odds ratio of group with abnormal blood pressure increased 1.41 fold (95% CI, 1.10~1.82). For correlation of woman's MS to missing teeth, it was found that the odds ratio of missing teeth in the group with MS increased 1.48 fold (95% CI, 1.07~2.04). It is considered that a public health project comprising preventive and systematic disease management is necessary for controlling MS and oral disease. The findings of the study are expected to lay the foundation for the development of oral health promotion programs.

• Economic and Environmental Geology
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• v.53 no.1
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• pp.33-43
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• 2020

CO₂ geological storage is currently considered as the most stable and effective technology for greenhouse gas reduction. The saline formations for CO₂ geological storage are generally located at a depth of more than 800 m where CO₂ can be stored in a supercritical state, and an extensive impermeable cap rock that prevents CO₂ leakage to the surface should be distributed above the saline formations. Trough analysis of seismic and well data, we identified the basalt flow structure for potential CO₂ storage where saline formation is overlain by basalt cap rock around PZ-1 exploration well in the Southern Continental Shelf of Korea. To evaluate CO₂ storage capacity of the saline formation, total porosity and CO₂ density are calculated based on well logging data of PZ-1 well. We constructed a 3D geological grid model with a certain size in the x, y and z axis directions for volume estimates of the saline formation, and performed a property modeling to assign total porosity to the geological grid. The estimated average CO₂ geological storage capacity evaluated by the U.S. DOE method for the saline formation covered by the basalt cap rock is 84.17 Mt of CO₂(ranges from 42.07 to 143.79 Mt of CO₂).

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.16 no.4
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• pp.196-205
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• 2011

To investigate the contribution of macroalgae to biogeochemical nutrients and carbon cycles, we measured the uptake rates of nutrients and $CO_2$ and characteristics of fluorescence of Saccharina japonica (Laminaria japonica Areschoug) using an incubation method in an acrylic chamber. From January to May 2011, S.japonica was sampled at Ilkwang, one of well-known macroalgae culture sites around Korea and ranged 46~288 cm long and 4.8~22.0 cm wide of whole thallus. The production rate of dissolved oxygen by S. japonica (n=25) was about $6.9{\pm}5.8{\mu}mol\;g^{-1}$ fresh weight(FW) $h^{-1}$. The uptake rate of total dissolved inorganic carbon ($TCO_2$), calculated by total alkalinity and pH, was $8.9{\pm}7.9{\mu}mol\;g^{-1}\;FW\;h^{-1}$. Mean nutrients uptake were $175.6{\pm}161.1\;nmol\;N\;g^{-1}\;FW\;h^{-1}$ and $12.7{\pm}10.1\;nmol\;P\;g^{-1}\;FW\;h^{-1}$. There were logarithmic relationships between thallus length and uptake rates of nutrients and $CO_2$, which suggested that younger specimens (<100-150 cm) were much more efficient at nutrients and $CO_2$ uptake than old specimens > 150 cm. There was a positive linear correlation ($r^2$=9.4) existed between the dissolved oxygen production rate and the $TCO_2$ uptake rate, suggesting that these two factors may serve as good indicators of S. japonica photosynthesis. There was also positive linear relationship between maximal quantum yield ($F_v/F_m$) and production/uptake rates of dissolved oxygen, $TCO_2$ and phosphate, suggested that $F_v/F_m$ could be used as a good indicator of photosynthetic ability and $TCO_2$ consumption of macroalgae. Maximum relative electron transport rate ($rETR_{max}$) of S. japonica increased as thallus grew and was high in distal part of thallus which may be resulted from the increase of photosynthetic cell density per area. The annual $TCO_2$ uptake by S. japonica in Gijang area was estimated about $1.0\sim1.7{\times}10^3C$ ton, which was about 0.02-0.03% of carbon dioxide emission in Busan City. Thus, more research should be focused on macroalgae-based biogeochemical cycles to evaluate the roles and contributions of macroalgae to the global carbon cycle.

• Journal of Nutrition and Health
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• v.49 no.4
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• pp.247-257
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• 2016

Purpose: The aim of this study was to investigate the relationship between instant noodle intake and metabolic factors in Korean adults. Methods: Study subjects were 5,894 (male 2,293, female 3,601) aged 19~64 years who participated in the 2013~2014 KNHANES. Information on frequency and consumption of instant noodles was obtained by the food frequency questionnaires method in KNHANES (Korean National Health and Nutrition Examination Survey), and subjects were classified according to age, sex, and instant noodle consumption (INC). Results: The frequency and consumption of instant noodles was 1.2 times/week and 1.2 servings in subjects. High INC group (${\geq}1$ serving/week) was significantly younger in age compared with the low INC group (< 1 serving/week). However, the high INC group had significantly higher waist circumference, metabolic factors (triglyceride, cholesterol, and HDL-cholesterol), and dietary intake (energy intake, fat, and sodium density) compared with the low INC group. Hyperglycemia showed association with higher risk of highest quartile of INC after adjustments for multiple confounding factors, including age, gender, household income, education, smoking, and alcohol compared with the lowest quartile (OR: 1.4, 95% CI: 1.1-1.8). In female, abdominal obesity showed association with higher risk of highest quartile of INC after adjustments for multiple confounding factors compared with the lowest quartile (OR: 1.6, 95% CI: 1.2-2.2). Conclusion: Consumption of instant noodles was associated with increased prevalence of abdominal obesity and hyperglycemia in women. These findings suggest an association of instant noodle consumption status with metabolic risk.

• Journal of Korean Society for Geospatial Information Science
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• v.23 no.1
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• pp.101-111
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• 2015

Stream restoration projects have become threats to riparian ecosystem in Rep. of korea. Riparian wildlife becomes isolated and the animals are often experience difficulties in crossing riparian corridors. The purposes of this study is to select suitable wildlife passages for wild animals crossing riparian corridors. Maximum entropy model and snow tracking data on embankment in winter seasons were used to develop species distribution models to select suitable wildlife passages for water deer. The analysis suggests the following. Firstly, most significant factors for water deer's habitat in area nearby riparian area are shown to distance to water, age-class, land cover, slope, aspect, digital elevation model, tree density, and distance to road. For the riparian area, significant factors are shown to be land cover, size of riparian area, distance to tributary, and distance to built-up. Secondly, the suitable wildlife passages are recommended to reflect areas of high suitability with Maximum Entropy model in riparian areas and the surrounding areas and moving passages. The selected suitable areas are shown to be areas with low connectivity due to roads and vertical levee although typical habitats for water deer are forest, grassland, and farmland. In addition, the analysis of traces on snow suggests that the water deer make a detour around the artificial structures. In addition, the water deer are shown to make a detour around the fences of roads and embankment around farmland. Lastly, the water deer prefer habitats around riparian areas following tributaries. The method used in this study is expected to provide cost-efficient and functional analysis in selecting suitable areas.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.1
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• pp.15-24
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• 2015

$CH_4$ is a trace gas and one of the key greenhouse gases, which requires continuous and systematic monitoring. The application of eddy covariance technique for $CH_4$ flux measurement requires a fast-response, laser-based spectroscopy. The eddy covariance measurements have been used to monitor $CO_2$ fluxes and their data processing procedures have been standardized and well documented. However, such processes for $CH_4$ fluxes are still lacking. In this note, we report the first measurement of $CH_4$ flux in a rice paddy by employing the eddy covariance technique with a recently commercialized wavelength modulation spectroscopy. $CH_4$ fluxes were measured for five consecutive days before and after the rice transplanting at the Gimje flux monitoring site in 2012. The commercially available $EddyPro^{TM}$ program was used to process these data, following the KoFlux protocol for data-processing. In this process, we quantified and documented the effects of three key corrections: (1) frequency response correction, (2) air density correction, and (3) spectroscopic correction. The effects of these corrections were different between daytime and nighttime, and their magnitudes were greater with larger $CH_4$ fluxes. Overall, the magnitude of $CH_4$ flux increased on average by 20-25% after the corrections. The National Center for AgroMeteorology (www.ncam.kr) will soon release an updated KoFlux program to public users, which includes the spectroscopic correction and the gap-filling of $CH_4$ flux.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.1
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• pp.1-7
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• 2010

This study was carried out to investigate plow pan characteristics and to grasp the relationship between its particle size distribution fractal dimension ($D_m$) and water transport in paddy plow pan. Twenty four soil sampling sites with different management groups, ordinary and sandy-textured, were selected and investigated for physical properties of soils such as Yamanaka hardness in April, non-submerged condition, before rice seedling transplanting. The plow pan appearing depth and thickness was determined by penetration resistance profile. Undisturbed core samples with five replicates were sampled at plow pan layerwith 2 inch cores for measuring soil bulk density and saturated hydraulic conductivity. The particle size distribution fractal dimension ($D_m$) was calculated by the method following the procedure Tylerand Wheacraft (1992), using the USDA-based particle size analysis datawith fractions of 0-0.002, 0.002-0.053, 0.053-0.1, 0.1-0.25, 0.25-0.5, 0.5-1.0, and 1.0-2.0 mm. The plow pan of investigated fields appeared at a range from 5 to 30 cm depth, showing minimum value in sandy-textured management group and maximum value in ordinary management group. The thickness of plow pan were distributed from 5 to 17 cm, showing both minimum and maximum values in sandy-textured management group. Averagely, the plow appearing depth were deeper in ordinary management group than in sandy-textured management group, whereas the reverse in the thickness of plow pan. The particle size distribution fractal dimension ($D_m$) had higher value with finer textures, with higher fractality in coarser texture. Saturated hydraulic conductivities, $K_s$, of plow pan soils distributed from 0.5 to 1420 mm $day^{-1}$, having the highest value in sandy skeletal soils. The $K_s$ decreased with decreasing clay content and $D_m$, showing power function relationships. The coefficient of determination, $R^2$, of the fitted power functions were higher in $D_m$ as x-axis than in clay content. This means that $D_m$ could give us more effective estimation than clay content. Especially, sandy-textured paddy soils had higher $R^2$, compared to ordinary paddy soils. $K_s$ of relatively coarse-textured soils with less than 18%of clay content, therefore, was more dependent on particle size distribution than that of relatively fine-textured soils. From these results, it could be concluded that the fractal scaling gives us a unique quantity describing particle size distribution and then can be applied to estimate saturated hydraulic conductivity, especially more effective in coarse-textured soils.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.2
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• pp.112-129
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• 2012

The aim of this study was to provide basic data in managing the project that was carried out on Bulgwangcheon in a nature-friendly way to improve the conditions around the areas, which was brought to completion in 2002, based on changes in ecological characteristics. For this propose, this study examined documents related to the project, compared physical and enviromnental changes before and after the project was conducted and analyzed changes in the stream ecosystem. The result showed that in areas that effluent water was often observed, especially when it rained, the river wall was washed away and vegetation was found damaged. As for actual vegetation, this study compared planting coverage of each section of the research area and actual vegetation charts. The results indicated that Lespedeza spp., Aster koraiensis among mixed seeds that were planted in the reservoir path were almost swept away while Festuca arundinacea dominated the areas. Phragmites communis, Miscanthus sacchariflorns and Salix gracilistyla which had been planted in a small number were also almost washed out though a small number of them were left to form a colony. After examining the topography and structure of the plant community, this study found that areas where mixed seed were planted had changed into two types of vegetation: First type of area is dominated by P and R which are usually raised in apron with abundant floating particles. The second type of area is dominated by dry gramineous plant such as F and A. Areas around low flow channel where Phragmites communis, Miscanthus sacchariflorus and Salix gracilistyla planting construction method is applied was washed away with the width of low flow channel reduced. Though P, M and S formed a small community in some areas around the low flow area, they were in small number and in composition of simple plant species. Two ways were suggested in this study to manage the stream in an ecological way. First, adequate revetment construction methods should be applied by monitoring the flow of the stream as well as considering the flood control of urban streams. Second, target vegetation communities that are suitable for the environment of the stream should be chosen and be plantedconstantly with high density. At the same time, ornamental native plants shouldn't be planted as they have been and disturbing vegetation should be removed.