• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.4
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• pp.457-467
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• 2019

To investigate the long-term variation characteristics of nutrients in the east coast of Korea, water temperature, salinity, dissolved oxygen, and nutrients were measured at three stations of Sokcho, Jukbyeon and Gampo coasts for five years from 2013 to 2017. For five years, the water temperature of the East Sea coast was in the range of $1.2{\sim}28.8^{\circ}C$, the salinity was in the range of 30.63~34.79 and the dissolved oxygen (DO) was in the range of 3.53~7.64 mL/L. Distribution and variation of the water environment factors in the study area were determined by the vertical stratification of water column and distribution of water temperature. The high DO concentration in Sokcho coast From 2015 to August 2016 is presumed to be the result of the southward inflow of North Korean Cold Water (NKCW). Concentrations of dissolved inorganic nitrogen (DIN, $NH_4-N+NO_2-N+NO_3-N$) ranged $0.11{\sim}24.19{\mu}M$, phosphate concentration ranged $0.01{\sim}1.75{\mu}M$, and silicate ranged $0.17{\sim}32.80{\mu}M$. The N:P ratio was in the range of 0.7~54.3 (mean 15.2) and the N:P slope was in the range of 11.67~13.75. The N:P ratios in this study were lower than the Redfield ratio (16), indicating that nitrate did act as a limiting factor in phytoplankton growth. The correlation ($R^2$) of total N:P ratio was as high as 0.95, indicating that the effect of the surrounding land or non-point sources was not significant. In conclusion, the spatial and temporal variation of nutrients in the east coast of Korea was determined by the vertical mixing of water mass with thermocline and mainly affected by physical factors such as influx of external water masses and coastal upwelling, and the influences from inflows from the land were minimal.

• Korean Journal of Poultry Science
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• v.46 no.2
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• pp.55-63
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• 2019

This study was conducted to evaluate animal welfare approved farms in three housing systems (open, windowless, and free-range). The survey was conducted in 25 animal welfare approved farms, and 10 farms were surveyed for distribution status. The main breed in all animal welfare approved farms of laying hens was Hy-Line Brown variety. In the case of open house, laying hens were bred in traditional and panel houses simultaneously; however, the ratio of panel house was 58.3%, which was higher than that of the traditional house. All the windowless houses were made of panels and more than 15,000 laying hens were housed in a single windowless house. In the case of free-range house, it was maintained on a small scale of less than 12,000 birds. Fifty-six percent of the surveyed farms were breeding at $7{\sim}8birds/m^2$. In terms of male and female ratios, most farms maintained 1 male:15 females, but there was a farmhouse that switched 17 or 20 females to 1 male. The daily dietary allowance was 110~170 g, and 32% of the surveyed farms provided feed of more than 150 g/day, which showed that forage feed was important. The age of at the first egg was 123 days, 122 days, and 120 days, and the peak percent was 91.8%, 94.9%, and 86.5% in open, windowless and free-range houses, respectively. The average egg production rate was 74.0%, 84.6%, and 72.7% in open, windowless, and free-range houses respectively, thus, there was no correlation between feed intake and hen-housed eggs. Distribution of welfare certified eggs was mainly a direct deal with the consumer or through contract production. The ratio of direct transactions between large-scale marts and eco-friendly specialty stores of welfare approved eggs was higher than that of conventional eggs. The rate of contract sales of eggs in both the barn and free-range systems was high, and the percentage of courier sales farms was also high. Excluding courier services, price of eggs in the barn system rose to more than 30 won/egg in the second half of 2017 (after AI). Price of eggs in the free-range system rose to more than 50 won/egg in the second half of 2017 (after AI). In the case of courier sales, the same price of 500 won was maintained before and after AI. In conclusion, the results of this study can be used as basic data for improving the animal welfare certification system for laying hens in Korea.

• Journal of the Korean Society of Radiology
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• v.13 no.1
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• pp.65-71
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• 2019

With regard to current Neck CT, Bismuth shielding boards are often being used to reduce exposure to superficial organs such as the thyroid. However, beam hardening often occurs near superficial organs with Bismuth shielding boards and variations in CT Number, Noise, and Uniformity values occur severely. This study looked into the usefulness of shielding boards made from aluminum and silicone that can be easily obtained and have good machinability by comparing them to the existing Bismuth shielding board. An Aluminum 7.3mm and a Silicone 21.5mm were made with shielding ratios similar to that of the Bismuth(0.06 mmPb). TLD (TLD-100) was placed on the thyroid area of the Phantom (RS-108T) and 5 doses were measured for each. To compare image quality, CT Number and Noise variations in axial images of the thyroid area in Neck CT images were compared. Also, variations in CT Number, Noise, and Uniformity were measured in the AAPM phantom images and compared. In the results, when thyroid doses for each shielding board were compared, the Bismuth shielding board showed a 14% reduction, the Silicone 21.5mm showed a 15% reduction, and the Aluminum 7.3mm showed a 13% reduction compared to the Non-Shield. Statistically, there were no significant differences in comparison with the Bismuth shielding board. In CT Number variations of thyroid area images, variations were largest for the Bismuth shielding board. With Uniformity evaluations of the AAPM phantom, the Bismuth shielding board was found unsuitable and the Aluminum 7.3mm and Silicone 21.5mm satisfied the acceptance criteria. Research results show that the Aluminum 7.3mm and Silicone 21.5mm have a similar shielding ratio to the high-priced Bismuth shielding board that is currently being used clinically and in comparison tests of CT Number attenuation coefficient variations, Noise, and Uniformity which are phantom image evaluation items, they proved to be better than Bismuth shielding boards. If various shielding boards are made using aluminum and silicone, sized appropriately for superficial organs, it would be useful in decreasing patient doses.

• Journal of Korea Society of Waste Management
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• v.34 no.2
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• pp.205-213
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• 2017

The current study was performed to investigate the effect of recycling coir substrates on the growth, fruit yield, and quality of strawberry plants. Analysis of physical properties revealed that the pH of a fresh coir substrate was 5.04 while those of substrates reused for one and two years were 5.20 and 5.33, respectively. The electrical conductivity (EC) of a new substrate was as high as $4.58dS{\cdot}m^{-1}$. This can cause salt stress after transplanting. The EC tended to decrease as the substrate was recycled, and the EC of a two-year recycled substrate was $1.48dS{\cdot}m^{-1}$. The fresh substrate had lower nitrogen and calcium concentrations, but higher phosphate, potassium, and sodium concentrations than the recycled coir substrate. The coir substrates recycled for one or two years maintained better chemical properties for plant growth than the fresh substrate. Strawberry growth varied depending on the number of years that the coir substrate was recycled. In general, strawberries grown in substrates that had been reused for two years did better than those grown in substrates that had been reused once or were fresh. Ninety days after transplanting, a plant grown in a substrate that had been reused for two years contained 25 leaves, which was 3.6 more than with a fresh substrate. In addition, the plants grown in a substrate that had been reused for two years exhibited larger leaf areas than those grown in other substrates. Coir substrates that had been reused for one year increased the number and area of leaves, but not as much as the substrate that had been reused for two years. One- and two-year reused coir substrates increased the weight of strawberries produced relative to the unused substrate, but the difference was not statistically significant. The plants grown in two-year reused substrates were longer and wider, as well. Also, the number of fruits per plant was higher when substrates were reused. Specifically, the number of fruits per plant was 28.7 with a two-year reused substrate, but only 22.2 with a fresh substrate. The fruit color indices (as represented by their Hunter L, a, b values) were not considerably affected by recycling of the coir substrate. The Hunter L value, which indicates the brightness of the fruit, did not change significantly when the substrate was recycled. Neither Hunter a (red) nor b (yellow) values were changed by recycling. In addition, there were no significant changes in the hardnesses, acidities, or soluble solid-acid ratios of fruits grown in recycled substrates. Thus, it is thought that recycling the coir substrate does not affect measures of fruit quality such as color, hardness, and sugar content. Overall, reuse of coir substrates from hydroponic culture as high-bed strawberry growth substrates would solve the problems of new substrate costs and the disposal of substrates that had been used once.

• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.3
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• pp.41-48
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• 2021

This study aimed to develop an alternative organic fertilizer to castor oil cake-based fertilizers. To assess the nutrient effect of the developed fermented mixed organic fertilizers, the yield of lettuce and soil characteristics after growth were analyzed and compared to those of a trial using a mixed expeller cake fertilizer. Two fermented mixed organic fertilizers, FA and FB, each containing 5.0% nitrogen, 2.6% phosphate, and 1.4% potassium, were produced by mixing different ratios of rice bran, dried distillers grains, sesame oil meal, and fish meal. This study was conducted with six trials: untreated, mixed expeller cake fertilizer, and the fermented mixed organic fertilizers FA and FB. Based on the amount of nitrogen fertilization (70 kg ha^-1) on the lettuce, the fermented mixed organic fertilizers FA and FB were applied at 100% and 150%, respectively, and the mixed oil cake was applied at 100%. As the amount of treatment increased, there was no significant difference except the number of leaves in FA treatment. The yields from the FA100 and FB100 treatments were 38.2 and 40.8 Mg ha^-1, respectively, which was not significantly different from that of the mixed expeller cake fertilizer treatment at 38.3 Mg ha^-1. In addition, the nitrogen uptake and utilization efficiency of the lettuce were not significantly different between mixed expeller cake fertilizer and fermented mixed organic fertilizer treatments. Analysis of the chemical properties of the soil after the trial showed that he mixed expeller cake fertilizer treatment showed the lowest pH. There were no significant differences in electrical conductivity, content of soil organic matter, available phosphate, and exchangeable cation among the fertilizer treatments. However, the bacterial and actinomyces density was higher in the soil from the fertilizer trials than in the non-fertilizer trials. These results indicated that the two tested fermented mixed organic fertilizers had nourishing effects and soil characteristics that were similar to those of the mixed expeller cake fertilizer. Thus, farmers can use these fermented mixed organic fertilizers as alternatives to castor oil cakes for the cultivation of organic lettuce.

• Journal of Korea Foundry Society
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• v.41 no.2
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• pp.144-152
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• 2021

Based on the analysis of the current state of the world's foundry industry, we looked at the international competitiveness of Korea's foundry industry for the past 20 years. Korea's total foundry production is 2.52 million tons, and the production per company (so-called productivity) is 2,831 tons, which is the eighth largest in the world and down one position for the case of total foundry production, while productivity remains its position compared to three years ago. Korea is the only one of the top 10 foundry to see a decline in production. Similar to the global situation, Korean products consist of 38% of grey csat iron, 31% of ductile cast iron, 15% of aluminum, and 9% of cast steel. In order to obtain statistics on Korea's foundry industry, the survey conducted a service project for approximately nine months from April 2020. Various statistical surveys and sample in-depth surveys by the Korean standard industry class were evaluated for various contents of the domestic casting industry. We also looked at the number of companies, the distribution by region, the number of workers and the percentage of foreigners, and the distribution of each job, as well as the R&D investment status according to the size of the enterprise. Together, sales, exports, sales and various profit ratios were analyzed to measure the earning power of foundry industry. In addition, the classification by grouping the foundry industry according to the process utilized by focusing on each company, and to determine the sales, exports, and yield status for each process was also investigated on the basis. Based on these data, the domestic foundry industry has presented a variety of offers for the following issues for sustainable growth; global ranking, marginal corporate restructuring, training of domestic technical people, differentiated support policies by company size and process.

• Applied Chemistry for Engineering
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• v.22 no.6
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• pp.685-690
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• 2011

In this study, a solvothermal reaction to prepare nanocrystalline titania was carried out using $TiCl_4$ and mixed solvents of alcohol and water. The effects of the type and the composition of alcohol on the crystal structure and agglomeration of final $TiO_2$ products were investigated. The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) as well as scanning electron microscopy (SEM). In the solvothermal reaction using the n-butanol solutions with different volume ratios of n-butanol/water (100/0, 75/25, 50/50, 25/75, 0/100), the extent of agglomeration of obtained rutile $TiO_2$ was found to change with the volume ratio of n-butanol/water, and the n-butanol/water ratio of 75/25 revealed the best result for the preparation of well-dispersed nanocrystalline $TiO_2$ powders. The crystal phase of $TiO_2$ prepared through the solvothermal reaction changed with the type of alcohol in solvent (alcohol/water = 75/25). $TiO_2$ products obtained with the aqueous solutions of methanol, ethanol and isopropanol have an anatase phase, while that with n-butanol has a rutile phase. The results showed that, in the solvothermal reaction using both $TiCl_4$ as a starting material and the alcohol-water mixed solvents without any other additive, the enhancement of dispersion and control of crystal structure of $TiO_2$ products can be feasible by simply varying the composition and type of alcohol in the mixed solvents.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.4
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• pp.70-77
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• 2011

This study takes road landscape of traditional Chinese Kangnam gardens in Suzhou as the object. It compares the relations and differences between preferences of Korean and Chinese on road landscapes with different rockery ratios, and studies the differences between Korean and Chinese's adjective visual characteristics of road landscape of traditional gardens and impacts of visual characteristics on preference. The following is the research process: Firstly, the theoretical survey of road landscape of traditional Chinese Kangnam gardens is conducted, pictures of the road landscape of gardens in Suzhou are taken, and 15 pictures are selected based on rockery ratio. Secondly, in order to grasp the visual preference and landscape characteristics of road landscape of garden in Suzhou, 15 pictures and 21 pairs of adjectives are adopted for the questionnaire survey. Thirdly, in order to grasp the differences between preferences of Korean and Chinese on road landscape of traditional Chinese Kangnam gardens, thet-test analysis is conducted. In order to grasp the impacts of rockery ratio on preference, and after the classification of landscape pictures based on rockery occupancy, the average analysis, factor analysis of results of questionnaire survey for Korean and Chinese are conducted respectively. In order to grasp the differences of incentives of landscape preference, the incentive analysis of results of questionnaire survey for Korean and Chinese is carried out. In order to grasp the impacts of various factors on the preference, The results are as follows: The results of analysis of differences between Korean and Chinese's preference on road landscape of traditional Chinese Kangnam gardens show that the overall preference of Chinese is higher than that of Korean. The results of the landscape preference analysis show that the ranking order of average value of Korean and Chinese's preference on rockery ratio categories is: medium ratio, very small ratio, small ratio, large ratio, very large ratio. The results of analysis of relations between rockery ratio of traditional Chinese Kangnam gardens and preference show that the preference increases as the rockery ratio decreases, and the rockery ratio variation causes greater impacts on Korean. Results of the analysis of visual characteristics, factors of visual characteristics of Koreans are "aesthetic factor", "comfort factor", "neat(orderly) factor", and "fun factor". The visual characteristics of Chinese has three factors, namely "psychological factor", "comfort factor", and "neat factor".

• Journal of Mushroom
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• v.18 no.4
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• pp.344-356
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• 2020

This study aimed to investigate the biological activities and amino acid content in the mixtures of roasted edible mushrooms (Pleurotus ostreatus, and Lentinula edodes) and grain additives (oat and brown rice) obtained under different extraction conditions for the development of mushroom tea. The total amount of polyphenol and β-glucan in edible mushrooms was increased with the roasting treatment compared to that observed with the air-drying treatment. In addition, DPPH radical scavenging activity and the amount of all amino acid components, including glutamic acid (Glu), were higher in the oat extracts than those observed in the brown rice. The biological activities and nutrient content were examined based on extraction temperatures and thetime required to obtain the mixtures of edible mushrooms and grain additives. The extract of a 1:1 mixture of L. edodes + oat (LE+O) obtained at 100℃, 3 min showed high DPPH radical scavenging activity (33.5%), and the extract of 3:1 mixture of P. ostreatus + brown rice (PO+B) obtained at 100℃, 3 min showed high nitrite scavenging activity (49.9%). The total polyphenol content of the extract of 3:1 mixture of P. ostreatus + brown rice (PO+B) was the highest when obtained at 16.2 mg GAE/g and+ brown rice (PO+B) was the highest when obtained at 16.2 mg GAE/g and 70℃, 10 min. The essential amino acid content was higher in the 1:1 mixing ratio of P. ostreatus + oat (PO+O) and P. ostreatus + brown rice (PO+B) and 3:1 mixing ratio. L. edodes + oat (LE+O) and L. edodes + brown rice (LE+B) compared to that observed in other mixing ratios.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.1
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• pp.15-33
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• 2021

In this study, the possibility of discriminating Fire blight (FB) infection tested using the hyperspectral imagery. The reflectance of healthy and infected leaves and branches was acquired with 5 nm of full width at high maximum (FWHM) and then it was standardized to 10 nm, 25 nm, 50 nm, and 80 nm of FWHM. The standardized samples were divided into training and test sets at ratios of 7:3, 5:5 and 3:7 to find the optimal bands of FWHM by the decision tree analysis. Classification accuracy was evaluated using overall accuracy (OA) and kappa coefficient (KC). The hyperspectral reflectance of infected leaves and branches was significantly lower than those of healthy green, red-edge (RE) and near infrared (NIR) regions. The bands selected for the first node were generally 750 and 800 nm; these were used to identify the infection of leaves and branches, respectively. The accuracy of the classifier was higher in the 7:3 ratio. Four bands with 50 nm of FWHM (450, 650, 750, and 950 nm) might be reasonable because the difference in the recalculated accuracy between 8 bands with 10 nm of FWHM (440, 580, 640, 660, 680, 710, 730, and 740 nm) and 4 bands was only 1.8% for OA and 4.1% for KC, respectively. Finally, adding two bands (550 nm and 800 nm with 25 nm of FWHM) in four bands with 50 nm of FWHM have been proposed to improve the usability of multispectral image sensors with performing various roles in agriculture as well as detecting FB with other combinations of spectral bands.