• Journal of Korea Water Resources Association
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• v.54 no.spc1
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• pp.1023-1035
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• 2021

The electricity cost of a desalination facility was also predicted and reviewed, which allowed the proposed model to be incorporated into the future design of such facilities. Input data from 2003 to 2014 of the Korea Hydrographic and Oceanographic Agency (KHOA) were used, and the structure of the model was determined using the trial and error method to analyze as well as hyperparameters such as salinity and seawater temperature. The future seawater quality was estimated by optimizing the prediction model based on machine learning. Results indicated that the seawater temperature would be similar to the existing pattern, and salinity showed a gradual decrease in the maximum value from the past measurement data. Therefore, it was reviewed that the electricity cost for seawater desalination decreased by approximately 0.80% and a process configuration was determined to be necessary. This study aimed at establishing a machine-learning-based prediction model to predict future water quality changes, reviewed the impact on the scale of seawater desalination facilities, and suggested alternatives.

• Journal of Aquaculture
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• v.22 no.1
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• pp.28-33
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• 2009

Physiological responses (hematological factors, cortisol, glucose, osmolality, $Na^+$, $K^+$ and $Cl^-$) in starry flounder Platichthys stellatus were investigated during freshwater acclimation in the conditions of different speeds in salinity change with acute-decrease (AD) or stepwise-decrease (SD I and II). In AD of acute-decrease salinity, hematocrit (Ht), red blood cell (RBC) and hemoglobin (Hb) were rapidly increased more than SD I of stepwise-decrease salinity. But in case of SD II, Ht, RBC and Hb were no significant difference from beginning to end of this experiments. In AD, cortisol level significantly increased from $2.1{\pm}1.0{\mu}g/mL$ at the beginning to $13.7{\pm}0.2{\mu}g/mL$ at 6 hours and recovered to the basal levels ($3.1{\mu}g/mL$) at 10 days. In SD I, cortisol level was significantly increased from $2.1{\pm}1.0{\mu}g/mL$ at the beginning to $13.6{\pm}0.6{\mu}g/mL$ at 6 hours and recovered to the basal levels ($3.1{\pm}0.4{\mu}g/mL$) at 10 days. In SD II, cortisol level was a little increased from $2.1{\pm}1.0{\mu}g/mL$ at the beginning to $10.5{\pm}2.5$, $10.8{\pm}5.6{\mu}g/mL$ at 6, 12 hours and recovered to the basal level at 48 hours. Glucose level of AD, SD I, II were no significant difference from beginning to end of this experiments. Osmolality was $286.8{\pm}3.3\;mOsm/kg$ at the beginning. In SD II of stepwise-decrease, osmolality was no significant difference during rearing in freshwater (FW). But AD of stepwise-decrease and SD I of stepwise-decrease, osmolality was a little decreased end of this experiments. In AD of acute-decrease, only $Cl^-$ level was showed no significant difference from beginning to end of experiment and $Na^+$, $K^+$ levels were decreased. In case of SD I, $Cl^-$ level was showed no significant difference from beginning to end of experiment and $Na^+$, $K^+$ levels were decreased.

• Journal of Life Science
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• v.22 no.11
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• pp.1463-1469
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• 2012

To add functional specialty in a traditional fermentation product, Gochujang, and improve the taste and preference, an optimum fermentation condition of Gochujang supplemented with tomato puree was established in the conditions of GCJ 14, -16, -18, and -20. Varying the salinity concentration and the manufactured fermentation products, Gochujang was analyzed by the chemical nature, change in bacterial characteristics and contents of a functional chemical, lycopene, and sensory taste. As a result, the pH change of Gochujang containing tomato puree with grain syrup was diminished during the fermentation process. Its sugar contents were repeated by the increase and decrease. In addition, the water contents, salinity, and chromaticity of the Gochujang showed no significant change. Regarding the change in bacterial characteristics, total bacterial number and lactic acid bacteria number increased, with the rate of increase depending on the fermentation process. The ratio of lactic acid bacteria number against total bacterial number was confirmed to be significantly high at the conditions of GCJ 18 and -20. No significant change in the contents of lycopene was observed during the fermentation process. Notably, the change in crude proteins, crude fat, crude ash, and carbohydrates in addition to a sensory examination including taste and preference of the manufactured Gochujang suggest that the optimal fermentation product is produced in the condition of GCJ 20. Therefore, functional Gochujang satisfying a modern preference can be produced by using tomato puree with grain syrup.

• Journal of Soil and Groundwater Environment
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• v.18 no.3
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• pp.11-22
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• 2013

SEAWAT, a linked modeling program of Visual MODFLOW was used to analyze the change in groundwater levels and salinity related groundwater dam construction in Cheongsan island, Wando-Gun, Jeollanam-Do. The steady-state model results show the groundwater flow and salinity distribution of the studied area. The groundwater flows from north-west and south-east highlands into the river, located in the middle part of the basin, and is eventually discharged to the ocean. Part of the sea water infiltrates into the river; and through the estuary's alluvium aquifer, the sea water intrusion takes place spreading to about 830 m from the ocean. The transient model results show that after the groundwater dam construction, groundwater levels will rise to a maximum of 2.0 m upstream, and the groundwater storage will increase 21,000 after 10 years. Meanwhile 31% of the total area affected by sea water intrusion will decrease. To conclude, the groundwater dam is a very useful method for a secure water resource in preparation for drought and water shortages in the island regions.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.4
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• pp.545-552
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• 2011

Fernbraken is a popular and well-known wild grass, but the physiochemical properties of Korean Traditional pickling (Jangachi) during aging have been little reported. Therefore, this study was carried out to investigate the physiochemical properties of Fernbraken Jangachi treated with a soybean sauce mixture for 6 weeks (1st pretreatment) as well as fermented with soybean paste, red hot pepper paste and soybean sauce for 7 weeks. Total polyphenol contents, acidity, salinity, sweetness (Brix), and ${\alpha}$-tocopherol of Fernbraken Jangachi all increased with aging period. On the other hand, pH and total acidity of Fernbraken Jangachi did not change much. Among the three kinds of Jangachies, Jangachi fermented with soybean sauce showed 2 fold higher salinity and total acidity levels compared to the others. Therefore, the physiochemical properties of Fernbraken Jangachi were dependent on the pickling properties, such as soybean paste, hot pepper paste or soybean sauce, and these properties maintained a certain level after 5~6 weeks of aging. Further, proper aging period for Fernbraken Jangachi was suggested as 10 weeks.

• The Journal of Engineering Geology
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• v.13 no.3
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• pp.281-292
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• 2003

We setup a continuous measurement system for electrical conductivity of fluid in a model borehole and verified the basic environments in electrical conductivity measurement for estimating hydraulic constants. The experiment was made by monitoring the conductivity change within the hole using NaCI solution of different salinities and incoming formation fluid using distilled water. The experiment was made under the state of constant flow rate by maintaining balance between inflow and outflow. Conductivity variation features were observed by controlling salinity contrasts and temperature differences between fluid within the hole and incoming formation fluid. flow rate and the location of inlet and outlet. The results of the experiment show well the role of each affecting factor on the conductivity distribution. and suggest appropriate environments for conductivity measurements. It is considered that the basis of the conductivity measurement for henceforward laboratory model and/or in-situ borehole experiment has been prepared.

• Journal of Korean Society on Water Environment
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• v.30 no.3
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• pp.304-310
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• 2014

The conventional methods for total residual chlorine such as iodometry and DPD colorimetric can cause secondary pollution due to additional agents, also have a wide error range. As for alternative, electrochemical method can measure TRC(Total residual chlorine), and is not required as additional agents, also very suitable for using the fields of ballast water because test time is relatively fast. Therefore, this study was investigated for changing charge by agitation, salt concentration, and temperature change. Charge showed differences based on changes of reduction peak with or without agitation. In contrast, TRC and charge were well correlated in constant agitation speed. As TRC and charge were analyzed with high correlations in constant salinity and temperature of ocean, thereby conductivity was firstly measured, and charge had high correlation for TRC in spite of changing salinity and temperature Pt electrode revealed high reliability ($r^2=0.960$) because it was rarely effected by TRC, On the other hand, Au electrode appeared inadequate ($r^2=0.767$) to use sensor in less than 1.0 ppm of TRC. For high accuracy and detection of TRC, Pt and Au electrodes for test time were, respectively, 14 and 22 seconds. As a result, Pt electrode was more valuable than Au electrode in terms of response time.

• Journal of Environmental Science International
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• v.21 no.3
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• pp.313-326
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• 2012

Three embankments, namely Changpo, Bokkil and Guil, in Chunggye Bay were investigated to assess the influence of environmental changes to phytoplankton size structure, distribution of species and standing crops. Three stations was sampled near at each embankment in Nov. 2006, Feb. 2007, May 2007 and Aug. Phytoplankton were classified into net-size (>20${\mu}m$) and nano-size (<20${\mu}m$). In summer, the freshwater discharge seemed to have influence in the decrease of salinity and in the increase of turbidity, ammonium and phosphorus concentrations. Chl a concentration and phytoplankton abundance in Feb. 2007 were observed to be generally higher in all stations compared to other periods. Net-size phytoplankton was observed to be higher in Feb. 2007 and May 2007 compared to nano-sized phytoplankton. However, there was shift in phytoplankton composition in Nov. 2006 and Aug. 2007. Phytoplankton under seven class (Bacillariophyceae, Chlorophyceae, Chrysophyceae, Cryptophyceae, Cyanophyceae, Dinophyceae, Euglenophyceae) was identified during the study period. It was found out that the major phytoplankton class was Bacillariophyceae. Phytoplankton was more diverse in autumn compared to any other season. Cyanophyceae was increased in summer. In rainy season, change in physical factors (salinity, transparency) seemed to have more influence on phytoplankton growth compared to inorganic nutrients.

• 한국환경농학회:학술대회논문집
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• 2011.07a
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• pp.196-204
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• 2011

Abiotic stress is the primary cause of crop loss worldwide, reducing average yields for most major crop plants by more than 50%. In addition, future agricultural production and management will encounter multifaceted challenges from global climate change. Therefore, it is necessary to study the molecular response of crop plants to the stresses in order to develop appropriate strategies to sustain food production under adverse environmental conditions. We carried out a large scale proteomic analysis of soybean plants in response to various abiotic stresses, including drought, salinity, waterlogging and their interactions. Proteins were analyzed by two dimensional polyacrylamide gel electrophoresis followed by matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry. The identified proteins are involved in a wide range of cellular functions. In addition to the well known stress-associated proteins, we identified several novel proteins, which were not reported before. In many cases our proteomic data bridges the gap between mRNA and metabolite data. Our studie provides new insights into identification of abiotic stress responsive proteins in soybean, and demonstrates the advantages of proteomic analysis in dissecting metabolic and regulatory networks.

• Ocean and Polar Research
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• v.34 no.4
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• pp.431-444
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• 2012

We simulated and compared present and future ocean circulation in the East China Sea using an East Asia Regional Ocean model. Mean climate states for 1990~1999 and 2030~2039 were used as surface conditions for simulations of present and future ocean circulation, which were derived from the simulations of three different global climate models, ECHAM5-MPI, GFDL-CM2.0 and MIROC3.2_hires, for the 20th century and those of 21st century as projected by the IPCC SRES A1B. East Asia Regional Ocean model simulated the detailed patterns of temperature, salinity and current fields under present and future climate conditions and their changes instead of the simple structures of global climate models. To some extent, there are consistent ocean circulation changes derived from the three pairs corresponding to the global climate model in so much as the temperature increases not only in winter but summer at both the surface and bottom and that temperature and salinity changes are prominent near the Chinese coast and in the Changjiang bank. However, the simulated circulations are different among each other depending on the prescribed atmospheric conditions not only under present climate but also with regard to future climate conditions. There is not a coincident tendency in ocean circulation changes between present and future simulations derived from the three pairs. This suggests that more simulations with different pairs are needed.