• Korean Journal of Soil Science and Fertilizer
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• v.17 no.4
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• pp.399-405
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• 1984

The results of these experiments which were carried out to investigate the effects of rice straw for nitrogen metabolism and acetylene reducing activity, during rice plants were cultured under the percolated condition, are as follows. Azotobacter had tendency to increase with the passage of time, but decreased when rice straw was added. Population change of Clostridia was little as rice grew. Blue green algae increased until heading stage but decreased after the stage. And the application of rice straw increased the number of microorganisms. Thiorhodaceae were never detected, but yeast tended to increase slightly with passing time. Acetylene reducing activity was increased with increasing the number of nitrogen fixing microorganisms, and nitrogen fixing activity was between 0.2kg N/10 a and 0.4kg N/10 a during the growing season of rice plants. Though acetylene reducing activity was promoted by the use of rice plants on non-plant area, but the activity was not clearly affected by percolation.

• Journal of Environmental Science International
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• v.17 no.9
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• pp.1053-1068
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• 2008

This study aims to produce fundamental database for Environment Impact Assessment by monitoring vertical structure of the atmosphere due to the mountain valley wind in spring season. For this, we observed surface and upper meteorological elements in Sangin-dong, Daegu using the rawinsonde and automatic weather system(AWS). In Sangin-dong, the weather condition was largely affected by mountains when compared to city center. The air temperature was low during the night time and day break, and similar to that of city center during the day time. Relative humidity also showed similar trend; high during the night time and day break and similar to that of city center during the day time. Solar radiation was higher than the city, and the daily maximum temperature was observed later than the city. The synoptic wind during the measurement period was west wind. But during the day time, the west wind was joined by the prevailing wind to become stronger than the night time. During the night time and daybreak, the impact of mountain wind lowered the overall temperature, showing strong geographical influence. The vertical structure of the atmosphere in Dalbi valley, Sangin-dong had a sharp change in air temperature, relative humidity, potential temperature and equivalent potential temperature when measured at the upper part of the mixing layer height. The mixing depth was formed at maximum 1896m above the ground, and in the night time, the inversion layer was formed by radiational cooling and cold mountain wind.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.88-88
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• 2017

The study was conducted to analyze the growth characteristics comparison per planting density on the waxy corn early-planting culture for the paddy field in the southern province of south Korea. The cultivation period of early-planting culture for the paddy farming of the waxy corn are sown on February 15, 2016years, transplanting March 15 and harvest June 20. And it grew 126 days. The weather change according to the cultivation period of unheated plastic house early-planting culture, it was average temperature $14.6^{\circ}C$ and humidity 62.5%. And the temperature was 5.6 degrees Celsius warmer compared with the outside temperature and the humidity was 0.7 percent higher tendency. At the growth per planting density of waxy corn, culm length was average 224cm, the more it is high density culture the more was high trend. Stem diameter and ear length the more it is high density culture the more was lowed trend. The node number of $60{\times}20Cm$ was 12 nodes, fruit seting 5.7 nodes, tasseling number 94 days and silking number 96 days. In the ear characteristics per planting density, the size of ear length, seed setting length, ear width and ear weight the more planting density is high the more lowed that trend. The commodity percentage of planting density $60{\times}35Cm$ was the highest among other treatment as 69.1%. But, marketable yield was the highest planting density of $60{\times}20Cm$ as 4,543 ears/10a, and appeared in order $60{\times}25Cm$ 95%> $60{\times}30Cm$ 93%> $60{\times}35Cm$ 92%. The planting density on the waxy corn early-planting culture for the paddy farming in the southern province, the planting density analyzed to be effective planting of over 25% than normal season culture.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.2
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• pp.95-111
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• 2012

Relationship between plankton assemblage and environmental factors in a semi-closed Chunsu Bay was examined. Temporal changes in phytoplankton assemblage was rather drastic than those found in most Korean coastal area in the Yellow Sea primarily due to the seawater temperature (T) and nutrient input from the dikes nearby. Freshwater discharge seemed to cause winter time increase of Diatoms (February) and summer time increase of Dinoflagellates at surface (July to August). Structural change in cell size with time was also found in Diatom. Zooplankton community structure was also changed with season probably due to the food concentration, seawater temperature and salinity (S). From principal component analysis (PCA) of zooplankton distribution, it was postulated that seasonal environmental changes such as T and S could explain about 32% of variability in zooplankton distribution along with phytoplankton cell numbers, while freshwater discharge could explain about 17%. Comparing with past data of 1985-1986, 1991-1992, the distributional patterns and percent composition of major species, Acartia hongi, Paracalanus parvus sensu lato and Centropages abdominalis, were similar. However, the abundances have been increased more than three times. The composition of other taxa than copepods showed significant changes.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.1
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• pp.70-74
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• 2015

An LED plant factory farm is an alternative way to grow crops regardless of weather, season, and blight in such times of climate change. In recent years, it is a currently active and vibrant research field. The industry, which ranges from leaf vegetables to high value products, is expanding. This study was conducted to test tthe response of LED (Light-emitting diode) irradiation on the growth characteristics and ginsenoside levels indoors, in order to find out suitable light conditions. Ginseng seedling was transplanted from a styrofoam pot ($L{\times}W{\times}D$:$495{\times}315{\times}215mm$, inside diameter) into a closed plant production system in four blue LED (BL) and red LED (RL) different ratios of 1:1, 1;2, 1:3, 1:4 in a temperature range of $20{\sim}25^{\circ}C$, relative humidity of between 55 and 65%, and a 12-hour photoperiod. The LED irradiation shows the highest levels were found at 1:1 of BL and RL ratio at $61.21{\mu}mol\;s^{-l}m^{-2}$, 1:2 ratio $68.55{\mu}mol\;s^{-l}m^{-2}$, 1:3 ratio $63.85{\mu}mol\;s^{-l}m^{-2}$ and 1:4 ratio $62.41{\mu}mol\;s^{-l}m^{-2}$ from highest to lowest respectively. After analyzing from shoot and root 2 yers old ginseng plant which were cultivated under 1:3 irradiation of BL and RL ratio, it generally showed a positive effect under a 1:3 ratio of BL and RL.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.5
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• pp.687-693
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• 2005

The change of food components in seaweeds, masangi (Capsosiphon fulvecense), gashiparae (Enteromorpha prolifera) and cheonggak (Codium fragile) was investigated at various harvest times. The crude protein was $34.1\~43.8\%$ for masangi and $22.5\~35.7\%$ for gashiparae, respectively. The content of glutamic acid, aspartic acid and leucine among total amino acid was high. The major free amino acids were proline and alanine for masangi, asparagine and glutamic acid for gashipare, and hdyrolxyproline, glutamic acid and alanine for cheonggak. In gashipare, the content of aspargine was greatly decreased, while one of sarcosine was increased in March. The ratio of polyene was $63.91\~74.04\%$ for masangi, $62.87\~68.23\%$ for gashipare, and $40.26\~44.61\%$ for cheonggak. The levels of Ca, K, Mg and Fe were high. In masangi and gashiparae, the chlorophyll a and b was greatly decreased in March.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.1 s.24
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• pp.23-32
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• 2006

This study was conducted to find out the effects of meterological factors on oceanic conditions when cold and dry continental air mass passes through the western sea of Korea The change of ocean conditions during the winter season were more obvious in coastal area than open sea And sea surface temperature (SST) during February is lower by $3^{\circ}C$ than December but in coastal area SST dropped by $3^{\circ}C$. As for the salinity, there was not much difference between areas except southern area of Mokpo. In the coastal regions, air temperature(AT) and SST showed a positive correlation; as the air temperature goes up with the increase of SST and when the former goes down the latter decrease. SST of open sea seems to be changed by latent (Qe) and sensible heat (Qs), when the open sea lose its heat by Qe and Qs then SST goes down And when they get the heat then the SST goes up. 1here was a positive correlation between the AT of the coastal region and sea surface salinity (SSS), when the AT goes up then SSS increase and when the former goes down the latter decrease. Precipitation during the summer seasons (June$\sim$September) appeared to the more closely related with salinity of February of the following year than those of October and December.

• Journal of the Korean GEO-environmental Society
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• v.12 no.9
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• pp.13-20
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• 2011

There are many mountains in Korean Peninsula, and those used for the construction of roads and railways sectors are forming slopes. Slope collapse occurs with falling rocks and landslide because of the relaxation of the thawing rocks. The heavy rain in summer can also significantly contribute to the process, and abnormal climate change is much more influential than before. Therefore, rockfall-related accidents in rainy season are easily accessible in media every year. There has been a lot of research on application of strengthening compensation of the sections in order to minimize casualties and property damage. Rockfall Protection Net, however, has not been focused on much in the field yet. This study highlights the need of Rockfall Protection Net, since it can segregate the falling rocks inside the net relatively safely. Although there has been a little doubt about the effectiveness of rockfall protection facilities, it is obvious that relevant studies dealing with the solidity of the net are necessary for the rockfall protection net to be capable of supporting rockfall energies. As a result, Expanded metal strength is much more durable compared to the PVC coating net, and it is regarded as an excellent alternative material for the Rockfall Protection Net. In this study, the applicability of Expanded Metal as the alternative of Rockfall Protection Net is verified experimentally.

• Journal of Korea Water Resources Association
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• v.55 no.2
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• pp.121-133
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• 2022

The drought resulting from insufficient rainfall compared to the amount in an ordinary year can significantly impact a broad area at the same time. Another feature of this disaster is hard to recognize its onset and disappearance. Therefore, a reliable and fast way of predicting both the suffering area and the amount of water shortage from the upcoming drought is a key issue to develop a countermeasure of the disaster. However, the available drought scenarios are about 50 events that have been observed in the past. Due to the limited number of events, it is difficult to predict the water shortage in a case where the pattern of a natural disaster is different from the one in the past. To overcome the limitation, in this study, we applied the four RCP climate change scenarios to the water balance model and the annual amount of water shortage from 360 drought events was estimated. In the following chapter, the deep neural network model was trained with the SPEI values from the RCP scenarios and the amount of water shortage as the input and output, respectively. The trained model in each sub-basin enables us to easily and reliably predict the water shortage with the SPEI values in the past and the predicted meteorological conditions in the upcoming season. It can be helpful for decision-makers to respond to future droughts before their onset.

• Journal of Bio-Environment Control
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• v.32 no.1
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• pp.1-7
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• 2023

Understanding the light environment in greenhouse cultivation and the light utilization characteristics of crops is important in the study of photosynthesis and transpiration. Also, as the plant grows, the form of light utilization changes. Therefore, this study aims to develop a light extinction coefficient model reflecting the plant growth. To measure the extinction coefficient, five pyranometers were installed vertically according to the height of the plant, and the light intensity by height was collected every second during the entire growing season. According to each growth stage in the early, middle, and late stages, the difference between the top and bottom light intensity tended to increase to 69%, 72%, and 81%. When leaf area index and plant height increased, the extinction coefficient decreased, and it showed an exponential decay relationship. Three-dimensional model reflecting the two growth indexes, the paraboloid had the lowest RMSE of 1.340 and the highest regression constant of 0.968. Through this study, it was possible to predict the more precise light extinction coefficient during the growing period of plants. Furthermore, it is judged that this can be utilized for predicting and analyzing photosynthesis and transpiration according to the plant height.