• Korean Journal of Environment and Ecology
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• v.38 no.1
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• pp.79-89
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• 2024

The purpose of this study was to evaluate the area adjustment criteria and methods of the feasibility study of national park plans by applying them to Hallyeohaesang National Park. As a result of the ecological-based assessment used to identify the adjustment target areas, the ecological-based assessment Grades I and II that can be considered for inclusion were analyzed as 10.0% and 40.4%, respectively. Grade V, which can be considered for release, was 9.9%. As a result of the inclusion and release suitability assessment, the area subject to inclusion was 35.150 km² (3.669 km² on land and 31.481 km² at sea), and the area subject to release was 0.071 km² on land. When local governments and residents request the release of a park area for public interest or convenience, the release can be considered as long as the total area does not change, which is called a mutual exchange. The release area determined by mutual exchange was 10.386 km². It was 146 times the area determined by the suitability assessment for release. Matching the areas released by the mutual exchange with the ecological-based assessment, 70.6% (7.321 km²) was in Grades I and II, which can never be released. As a result, it was determined that the area adjustment of the feasibility study of Hallyeohaesang National Park was based on a very limited application of the results of the ecological-based assessment or the release suitability assessment. Also, mutual exchange was the key to area adjustment of the feasibility studies of national parks.

• Korean Journal of Environmental Biology
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• v.42 no.2
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• pp.193-206
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• 2024

This study aimed to quantify changes in forest cover and carbon storage of Korean Peninsular during the last two decades by integrating field measurement, satellite remote sensing, and modeling approaches. Our analysis based on 30-m Landsat data revealed that the forested area in Korean Peninsular had diminished significantly by 478,334 ha during the period of 2000-2019, with South Korea and North Korea contributing 51.3% (245,725 ha) and 48.6% (232,610 ha) of the total change, respectively. This comparable pattern of forest loss in both South Korea and North Korea was likely due to reduced forest deforestation and degradation in North Korea and active forest management activity in South Korea. Time series of above ground biomass (AGB) in the Korean Peninsula showed that South and North Korean forests increased their total AGB by 146.4Tg C (AGB at 2020=357.9Tg C) and 140.3Tg C (AGB at 2020=417.4Tg C), respectively, during the last two decades. This could be translated into net AGB increases in South and North Korean forests from 34.8 and 29.4 Mg C ha^-1 C to 58.9(+24.1) and 44.2(+14.8) Mg C ha^-1, respectively. It indicates that South Korean forests are more productive during the study period. Thus, they have sequestered more carbon. Our approaches and results can provide useful information for quantifying national scale forest cover and carbon dynamics. Our results can be utilized for supporting forest restoration planning in North Korea

• Korean Journal of Ecology and Environment
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• v.35 no.1 s.97
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• pp.28-35
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• 2002

The effect of physical parameters on water quality was analyzed using monitoring data of 193 agricultural reservoirs. The retention time of reservoirs ($t_d$) ranged between 10 and 140 days, and the ratio of drainage area (DA) to reservoir surface area (SA) was between 10 and 120. Both ratios of DA/SA and total area (TA)/ reservoir storage (ST) in Korean agricultural reservoirs were relatively greater than those in natural lakes in other countries. As retention time was plotted against DA/SA ratio, it was shorter in Korean reservoirs than natural lakes. The semi-logarithmic relationship between TA/SA and t>$t_d$ was $t_d\;=\;42.21(TA/ST)^{-1}$ (n = 50, $R^2\;=\;0.89$). While areal loading of total phosphorus (TP) was below $4\;gTP{\cdot}m^{-2}{\cdot}yr^{-1}$ in general, it exceeded $10\;gTP{\cdot}m^{-2}{\cdot}yr^{-1}$ in reservoirs where DA/SA ratio was greater than 100, which implies that areal loading of TP increases as DA/SA ratio increases. Chl-a concentration was positively related with the mean depth of reservoir, implying the higher Chl-a concentration with deeper the mean depth. Therefore, the deeper reservoir might be advantageous in water quality management perspective if other morphological conditions are similar. The empirical regression equation using physical parameters was also suggested in the estimation of TP concentration in the reservoirs. Combined information presented in this paper might be applicable to the water quality management in agricultural reservoirs.

• Korean Journal of Soil Science and Fertilizer
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• v.12 no.2
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• pp.99-107
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• 1979

The properties, land use and genesis of the Jang-weon series, Planosol-like soils, distributed in Cheong-do area were investigated. Planosol-like soils in Korea have been believed unsuitable for perennial crops but 34.6% (594ha) of the Jang-weon soils in Cheongdo-gun are used for perennial crops such as apples, persimmons, peaches, mulberry etc. With productivity more or less equal to alluvial soils. The reason for high productivity and a working hypothesis for the genesis of the fragipan is suggested with discussion.

• Journal of Environmental Impact Assessment
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• v.24 no.3
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• pp.287-299
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• 2015

If the Nakdong River estuary is to be sustainable, land use management practices need to consider bird habitat requirements, especially given that the area serves as an important migratory bird sanctuary. In this study, bird habitats found in the Nakdong River estuary were classified into 11 different types including Phragmites australiss, mud flat, farmland, open surface in freshwater, sand bar, riparian forest, Scirpus planiculmis, waterway, construction, grasslands, and open surface in sea or brackish water. Taking into consideration the regional characteristics, habitat properties, and landscape indices, a total of 12 study sites were analyzed. Mud flat, construction, farmland, and P. australis account for 80% of the total land area. The high area ratio of construction and farmland to other types of habitat revealed a high amount of historical human activity and intervention in the area. Both patch numbers as well as patch density were high in West Nakdong River, Samrak Waterfront, Maekdo River, and Daejeo Floodgate, with these areas showing the greatest fragmentation as well. Total numbers of species and individuals had a positive correlation with the area and the number of habitat types. Findings suggest that protecting the habitat area, especially in S. planiculmis, is the most important factor for bird habitat management and that future development could result in habitat loss, having a profoundly adverse impact on bird populations. Therefore, it is important that the total area should be carefully protected by land use regulations in order to ensure that the Nakdong River estuary maintains its functional integrity as a migratory bird sanctuary.

• Korean Journal of Plant Resources
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• v.33 no.5
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• pp.482-500
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• 2020

The purpose of this study was to identify the phytosociological vegetation structure through a sampling survey of Mt. Jirisan National Park. And it was conducted to provide the latest data for establishing a conservation and management plan for forest ecosystems. As a result of TWINSPAN classification, it was classified into 4 communities. Group I is the Fraxinus mandshurica - Acer pseudosieboldianum Community, group II is the Quercus serrata - Quercus variabilis Community, group III is the Quercus mongolica Community, group IV is the Pinus densiflora Community. Group I is dominated by Fraxinus mandshurica in the canopy layer, and Cornus controversa and Quercus mongolica compete and maintain dominance. Group II is dominated by Quercus variabilis and Quercus serrata in canopy layer, and Styrax obassia and Styrax japonicus compete in sub-tree layer. In group III, Quercus mongolica has a high dominance of 67% in canopy layer and 27% in the sub-tree layer, and Acer pseudosieboldianum competes with the Quercus mongolica in the sub-tree layer. In group IV, Pinus densiflora showed a high dominance of 74% in canopy layer. The sub-tree layer is dominated by Quercus mongolica, and is accompanied by competition between Carpinus tschonoskii and Fraxinus sieboldiana.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.94-101
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• 2019

In this study, the FEM technique was applied to design the shape of the horn that transmits ultrasonic vibration energy to the base material, and the shape of the welding horn with a one-wavelength bar shape used in the 20kHz region was designed. The shape design of the horn was performed by applying the rod longitudinal vibration theory to Ansys APDL (Ansys Parametric Design Language). Twenty-five models were designed using the ratio of the area of the input and output surfaces of the vibration and the length of the horn to derive the appropriate horn shape. The horn was designed with a total length of 130mm, a step length of 65mm, and an output area of 28.79mm. The horn was fabricated using the optimized dimensions, and the vibration and displacement characteristics of the horn were evaluated using the measurement system. Finally, a uniform longitudinal step horn was designed, and more than 97.4% of the uniformity of the tip was secured. The amplitude ratio of the optimized horn was improved by 51%.

• Korean Journal of Food Science and Technology
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• v.33 no.3
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• pp.366-372
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• 2001

Volatile flavor components in the mash of Takjus prepared by using Aspergillus oryzae nuruk were identified by using Gas Chromatography and Gas Chromatography-Mass Spectrometry. Twenty-four esters, 21 alcohols, 10 acids, 9 aldehydes and 4 others were found in the mash of Takju. Thirty six components including 13 esters and 12 alcohols were detected in the beginning of fermentation. Twenty nine components were more detected after second day of fermentation and 68 components were detected after 12 days of fermentation. Thirty five flavor components including 12 alcohols such as ethanol, 2-methyl-1-propanol, 3-methyl-1-butanol and benzeneethanol, 13 esters such as ethyl acetate, ethyl caprylate, ethyl butyrate and isoamyl acetate, 4 aldehydes and 6 acids were usually detected in the fermentation process. Ethanol was predominantly found in the range of $79.86{\sim}89.54%$ as a major component by using relative peak area. 3-Methyl-1-butanol, ethyl caprylate and benzeneethanol were some of the major volatile components through the fermentation respectively. Peak area of 2-methyl-1-propanol, 1-hexanol, 1-dodecanol, ethyl acetate, monoethyl butanoate, acetic acid and isobutylaldehyde among the same group were higher than other components depending upon fermentation time.

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.691-698
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• 2000

Volatile flavor components in the mash of takjus prepared by using Rhizopus japonicus nuruk were identified by using GC and GC-MS. Twenty-four esters, 19 alcohols, 9 acids, 10 aldehydes and 4 others were found in the mash of takju. Thirty nine components including 14 esters and 12 alcohols were detected in the beginning of fermentation. Seventeen components were more detected after second day of fermentation and 66 components were detected after 12 days of fermentation. Thirty eight flavor components including 12 alcohols such as ethanol, 2-methyl-1-propanol and 3-methyl-1-butanol, 14 esters such as ethylacetate, ethylcaprylate and isoamylacetate, 6 aldehydes and 5 acids were usually detected in the fermentation process. Ethanol was predominantly found in the range of 76.2149-92.1155% as a major component by using relative peak area. 3-Methyl-1-butanol, 2-methyl-1-propanol, ethyl caprylate, 2,3-butanediol and benzeneethanol were some of the major volatile components through the fermentation. Peak area of ethylacetate, diethyl succinate, octanoic acid, acetic acid and isobutylaldehyde among the same group were higher than other component depending upon fermentation time.

• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.944-950
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• 2005

Volatile flavor components of Takjus mash prepared using Aspergillus kawachii nuruk were identified by GC and GC/MS. Twenty-two esters, 20 alcohols, 10 acids, 8 aldehydes, and 3 others were found in Takju mash. Thirty two components including 13 esters and 13 alcohols were detected at beginning of fermentation. Thirteen more components were detected after second day of fermentation, and 63 additional components after 12 days of fermentation. Twenty nine flavor components including 12 alcohols such as ethanol, 3-methyl-1-butanol, 2-methyl-1-propanol, and benzeneethanol, 12 esters such as ethyl acetate, ethyl caprylate, and ethyl butyrate 3 aldehydes, and 2 acids were detected during fermentation. Major volatile components detected during fermentation included 3-methyl-1-butanol, ethyl caprylate, and benzeneethanol. Peak areas of 2-methyl-1-propanol, 1-hexanol, 2, 3-butanediol (D.L), 1-dodecanol, 2-phenylethyl acetate, ethyl acetate, and monoethyl butanoate were higher than those of other components depending upon fermentation period.