• Korean Journal of Remote Sensing
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• v.38 no.5_3
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• pp.925-938
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• 2022

Agricultural reservoirs are an important water resource nationwide and vulnerable to abnormal climate effects such as drought caused by climate change. Therefore, it is required enhanced management for appropriate operation. Although water-level tracking is necessary through continuous monitoring, it is challenging to measure and observe on-site due to practical problems. This study presents an objective comparison between multiple AI models for water-body extraction using radar images that have the advantages of wide coverage, and frequent revisit time. The proposed methods in this study used Sentinel-1 Synthetic Aperture Radar (SAR) images, and unlike common methods of water extraction based on optical images, they are suitable for long-term monitoring because they are less affected by the weather conditions. We built four AI models such as Support Vector Machine (SVM), Random Forest (RF), Artificial Neural Network (ANN), and Automated Machine Learning (AutoML) using drone images, sentinel-1 SAR and DSM data. There are total of 22 reservoirs of less than 1 million tons for the study, including small and medium-sized reservoirs with an effective storage capacity of less than 300,000 tons. 45 images from 22 reservoirs were used for model training and verification, and the results show that the AutoML model was 0.01 to 0.03 better in the water Intersection over Union (IoU) than the other three models, with Accuracy=0.92 and mIoU=0.81 in a test. As the result, AutoML performed as well as the classical machine learning methods and it is expected that the applicability of the water-body extraction technique by AutoML to monitor reservoirs automatically.

• Food Science and Preservation
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• v.21 no.2
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• pp.163-169
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• 2014

The effect of the combined argon (Ar) gas packaging treatment on the browning of fresh-cut potatoes was studied. Fresh-cut potatoes were prepared for the following six groups: dipping distilled water for 1 minute and air packaging (Cont); dipping in distilled water for 1 minute and argon gas packaging (AR); dipping in 1% ascorbic acid for 1 minute and air packaging (AA); dipping in 1% ascorbic acid for 1 minute and argon gas packaging (AAR); blanching at $35^{\circ}C$ for 30 minutes and air packaging (BL); and blanching at $35^{\circ}C$ for 30 minutes and argon gas packaging (BAR). The potatoes were washed, peeled, and sliced ($1.5{\times}1.5{\times}1.5$ cm) before treatment. The samples were packed with a 0.04-mm-thick OPP film and were stored at $5^{\circ}C$ for 9 days. During the storage, the $O_2$ concentration decreased in Cont but increased in the AR, AA, AAR, BL, and BAR groups. The $CO_2$ concentration increased during storage. The AR, AAR, and BAR groups showed high $L^*$ and low $a^*$, $b^*$ values (browning index). The growth of the total aerobic bacteria was also inhibited in the AR group. During storage, the PPO activity gradually increased, and the AR group showed lower PPO activity. The AA and AAR groups showed high DPPH radical scavenging activity. It was demonstrated that the argon gas packaging is effective in the quality maintenance of fresh-cut potatoes.

• Journal of Korean Society of Forest Science
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• v.101 no.3
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• pp.387-394
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• 2012

The study was conducted to develop an effective forest resources use models for an alternate use of abandoned quarry by an attitude survey. According to the result of survey, a pessimistic view due to dust, noise pollution, and forest damage was 5% higher than an affirmative view by economic benefits from the development of quarry. The 42% of the respondents preferred the alternate use of abandoned quarry and the 25% of the respondents wanted an art and cultural space. The optimum size of alternate use was 5-10 ha (43%) with the requirement of nearby residents (32%). According to the SWOT analysis for abandoned quarry, the strength factors were an effective use of land, the content development of modern industrial inheritance + cultural and art fusion, attraction for nearby city and visitors, a harmony of beauty landscape and clean environment, and a sustainable increase of domestic and foreign visitors with the 5-day-work week. The opportunity factors were the improvement of traffic networks through KTX and local highway, the creation of the new growth engines with the establishment of artistic creation belts, the providing of unique cultural and art space through grafting of tour and education, the creation of local income through stone processed goods, and the vitalization of local development through eco-city. The weakness factors were a psychological remoteness and backwardness, and the weakness of staying tour infra. The threat factors were a poor financial support for sustainable development in nearby quarry and a modify of legal and institutional system for the alternated use of abandoned quarry. The developed restoration models for the alternate use in abandoned quarry are classified to a sculpture park, a waterfall and lake park, a rock-climbing, a sports park + forest park, a native botanical garden, a culture and art park, a complex park, a water storage site, a water storage site to extinguish forest fire, a geriatric hospital, an agricultural facility, and a school site types etc. The results suggest that the alternate use in the abandoned soil and stone quarry is needed to establish facility use models with consideration of user's preference.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.7
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• pp.380-394
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• 2015

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.

• Journal of Wetlands Research
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• v.21 no.4
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• pp.384-391
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• 2019

Nutrients in stormwater runoff have raised concerns regarding water quality degradation in the recent years. Low impact development (LID) technologies are types of nature-based solutions developed to address water quality problems and restore the predevelopment hydrology of a catchment area. Two LID facilities, infiltration trench (IT) and infiltration planter (IP), are known for their high removal rate of nutrients through sedimentation and vegetation. Long-term monitoring was conducted to assess the performance and cite the advantages and disadvantages of utilizing the facilities in nutrient removal. Since a strong ionic bond exists between phosphorus compounds and sediments, reduction of total phosphorus (TP) (more than 76%), in both facilities was associated to the removal of total suspended solids (TSS) (more than 84%). The efficiency of nitrogen in IP is 28% higher than IT. Effective nitrification occurred in IT and particulate forms of nitrogen were removed through sedimentation and media filters. Decrease in ammonium- nitrogen (NH₄-N) and nitrite-nitrogen (NO₂-N), and increase in nitrate-nitrogen (NO₃-N) fraction forms indicated that effective nitrification and denitrification occurred in IP. Hydrologic factors such as rainfall depth and rainfall intensity affected nutrient treatment capabilities of urban stormwater LID facilities The greatest monitored rainfall intensity of 11 mm/hr for IT yielded to 34% and 55% removal efficiencies for TN and TP, respectively, whereas, low rainfall intensities below 5 mm resulted to 100 % removal efficiency. The greatest monitored rainfall intensity for IP was 27 mm/hr, which still resulted to high removal efficiencies of 98% and 97% for TN and TP, respectively. Water quality assessment showed that both facilities were effective in reducing the amount of nutrients; however, IP was found to be more efficient than IT due to its additional provisions for plant uptake and larger storage volume.

• Journal of Bio-Environment Control
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• v.29 no.4
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• pp.354-364
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• 2020

This study was conducted to examine the potential of inducing salinity stress on cylindrical paper pot tomato seedlings to inhibit overgrowth. Potassium fertilizers, sulfate of potash (K₂SO₄), muriate of potash (KCl), and monopotassium phosphate (KH₂PO₄), were prepared as two solutions of (5 and 10) dS·m^-1 salinity level, respectively, to investigate the influence on tomato (Lycopersicon esculentum Mill.) seedling growth. We also investigated the adaptability and survivability of treated tomato seedlings with high-salinity potassium (10 dS·m^-1 KCl) to harsh environmental conditions (water deficit, low temperature, and storage conditions). Repeated addition of high-salinity level KCl, K₂SO₄, or KH₂PO₄ markedly decreased the dry matter of shoot and root, leaf area, and net assimilate rates (NAR) but increased the stem diameter of seedlings. Among the three sources, the relative growth rate of plant height (RGR_H) was most sensitive to KCl addition; increasing salinity levels of KCl solution decreased the RGR_H of seedlings. The compactness, which directly reflects the stocky growth index, increased in KCl or KH₂PO₄ treatments. After a week's water deficit, severely wilted seedlings were observed in control seedlings (untreated with KCl), but no wilted seedlings were observed in the KCl treated seedlings, and the relative water content (RWC) of the untreated seedlings significantly decreased by 23 %, while that of the pretreated seedlings only decreased by 8 %. The increase in ion leakage of KCl treated seedlings at low temperatures was less than that of untreated seedlings. Furthermore, there was far lower damage proportion on pretreated seedlings at (9, 12, and 15)℃ storage temperatures after 20 days, compared with on unpretreated seedlings. Our results suggest that high-salinity potassium fertilizer, especially KCl, is effective in preventing tomato seedling overgrowth, while it also improves tolerance.

• Applied Biological Chemistry
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• v.50 no.4
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• pp.327-333
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• 2007

This study was conducted to examine antioxidant activities of Perilla frutescens var. acuta leaf. For the this purpose, DPPH radical scavenging activity, lipid oxidation inhibition, SOD-like activity, and xanthine oxidase inhibitor activity of water extract, ethanol extracts (30, 50, 70, and 95%) and the fractions obtained from these extracts were determined. The electron donating abilities of the chloroform fraction obtained from the 70% and 95% ethanol extracts were 50%, and that of the ethyl acetate fraction for all of the extracts was above 75%. In particular, the electron donating ability of the ethyl acetate fraction of the 70% ethanol extract showed the greatest activity with 200.5 ppm of $RC_{50}$ value. The 70% ethanol extract was most effective to inhibit the automatic oxidation of linoleic acid at $40^{\circ}C$ storage. The highest inhibition effects appeared in the chloroform and ethyl acetate fractions of the water extract, and the 30, 50, and 70% ethanol extracts, and the highest lipid oxidation inhibiting effect of the 95% ethanol extract occurred in the hexane and acetate fractions. The SOD-like activity of the water extract was 30.3%, and the activities of the various concentration of ethanol extracts were 28-32% and the activity of the 70% ethanol extract was the highest. The SOD-like activity of the ethyl acetate fraction of the 70% ethanol extract was highest with 1,549.0 ppm of $RC_{50}$ value. Xanthine oxidase inhibition activity was greatest in the water extract and the activities of the ethanol extracts were 36-41.2%. The xanthine oxidase inhibition activity of the ethyl acetate fraction of the water extract was highest. In summary, we found that electron donating ability, lipid oxidation inhibition, and SOD-like activity of Perilla frutescens var. acuta leaf were greatest in the ethyl acetate fraction of the 70% ethanol extract, and xanthine oxidase inhibition activity was highest in the ethyl acetate fraction of the water extract.

• Food Science of Animal Resources
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• v.35 no.3
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• pp.389-397
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• 2015

This study investigated the effects of Perilla frutescens var. acuta water extract (WEP) on the shelf life and physicochemical qualities of cooked beef patties. The WEP contained phenolic compounds (80.65 mg gallic acid equivalents/g) and had half-maximal effective concentrations of 0.437 and 4.509 mg/mL for scavenging of DPPH and ABTS⁺ radicals, respectively. Treatment with 0.6% WEP inhibited the growth of Escherichia coli O157:H7 (p<0.05). Based on the result of the antioxidative potential and antimicrobial potential of WEP, beef patties were prepared with three treatment groups: (1) beef patties without added antioxidant (control); (2) beef patties with 0.02% ʟ-ascorbic acid (BAA); and (3) beef patties with 0.6% WEP (BWEP). The pH and cooking loss of BWEP were lower and higher than those in the control, respectively (p<0.05). When cooked beef patties were stored for 21 d at 4℃, the total number of aerobic bacteria in BWEP was lower than those in the control on all days except day 14 (p<0.05). The TBARS values in BWEP were lower than those of controls on days 7, 14, and 21 (p<0.05). Compared to control and BAA, BWEP had lower L* and b* values and higher a* values throughout the storage period (p<0.05). Except on day 0, acceptability was higher in BWEP than in control and BAA (p<0.05). According to results, WEP can be used as a natural ingredient that improves the shelf life and sensorial qualities of meat products.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.2
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• pp.109-124
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• 1990

A rapid processing method for fish sauce of high quality stability and favorable flavor was investigated using mackerel waste as starting material. The chopped waste was homogenized with water and hydrolyzed by commercial proteolytic enzymes such as Complex enzyme-2000($2.18\cdot10^4$ U/g solid, Pacific Chem. Co.) and Alcalase ($1.94\cdot10^4$ U/g solid, Novo) in a cylindrical vessel with 4 baffles and 6-bladed turbine impeller. Optimal pH and temperature for the hydrolysis with Complex enzyme-2000 were 8.0 and $50^{\circ}C$, and those with Alcalase were 9.0 and $55^{\circ}C$. In both cases, the reasonabe amount of added water and enzyme concentration based on the waste weight were $40\%,\;3\%$ and hydrolyzing time was 100 min. Thermal treatment of the hydrolysate with $6\%$ of invert sugar for 2 hours at $90^{\circ}C$ was adequated to inactivation of the enzymes and pasteurization of the hydrolysate. Flavor, taste and color of the hydrolysate were improved during the thermal treatment in which the browning reaction products might participate and result in antioxidative and bactericidal effects. Combined use of $0.005\%$ of Caryophylli flos with $6\%$ of invert sugar was also effective for the improvement of taste. Yield of the fish sauce based on the total nitrogen of the raw waste was $93.7\~94.9\%$, and $87.6\~87.9\%$ of the total nitrogen in the fish sauce was in the from of amino nitrogen. The pH, salinity and histamine content of the fish sauce prepared with $15\%$ of table salt were $6.1\~6.2$, $14.0\~14.5\%$ and less than $10mg\%$, respectively. The fish sauce was stable on bacterial growth during the storage of 60 days at $26\pm3^{\circ}C$ and the quality was also maintained.

• Food Science and Preservation
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• v.21 no.1
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• pp.17-24
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• 2014

This study was conducted in order to evaluate the effect of postharvest ripening periods and packaging methods on maintaining the quality of fresh-cut winter squash. Winter squash (var. Bouchang) was ripened at $22^{\circ}C$ for 1 or 2 weeks after harvest. The samples were washed in tap water, sanitized in $100{\mu}L/L$ chlorine water, peeled, and cut into 16 parts. Samples were then vacuum packaged or non-vacuum packaged in $80{\mu}m$ nylon/polyethylene (Ny/PE) films and stored at $5^{\circ}C$ for 21 days. Results indicated that different postharvest ripening periods affected gas concentration, firmness, off-odor development, color, and overall quality of fresh-cut winter squash. Samples treated with 2-week ripening periods maintained quality with higher redness value and soluble solid content (SSC) and lower $CO_2$ concentration and off-odor development compared to samples treated with a 1-week ripening period. Non vacuum packaging was effective in increasing visual quality and reducing off-odor development. A combination treatment of 2-week ripening periods and non-vacuum packaging maintained good quality with the lowest off-odor development and the highest visual quality scores at the end of the storage period.