• Journal of the Korean Society of Industry Convergence
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• v.22 no.6
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• pp.739-748
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• 2019

In this study, cyclic triaxial tests were performed for liquefaction characteristics according to earthquake loading frequency. The test period was tested for 0.1Hz, 0.2Hz, 0.5Hz 1.0Hz, 1.5Hz. It was analyzed that the number of earthquake loading increases as the test result frequendy increases. Therefore, additional study of the liquefaction evaluation method was needed considering the local characteristics of the high frequency earthquakes in Korea and the cyclic triaxial test frequency(0.1Hz), which is mainly used in the design.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.6_2
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• pp.943-948
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• 2020

In this paper, we developed a fiber optic interferometer system based on frequency-swept laser. This frequency-swept laser with an external-cavity structure can generate a high coherent light with a linewidth of 132 kHz at 1552 nm. It also shows a superior swept linearity of R2 = 0.99995 under repetition rate of 200 kHz due to absence of mechanical moving parts in the laser cavity. By using a piezoelectric fiber optic stretcher, various vibration experiments were implemented, such as 0.5 to 2.0 kHz vibration signals with intervals of 0.5 kHz, with a sampling rate of 7 kHz. Real-time peak tracking can be successfully recovered according to the applied vibration frequency with high linearity of R2 = 0.99983.

• Journal of agriculture & life science
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• v.45 no.6
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• pp.95-108
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• 2011

The food quality characterization and safety Japanese flying fish roe (JFF-R), capelin roe (C-R), Pacific herring roe (PH-R) were investigated. The size of JFF-R was 1.48-1.93 mm, which was longer than those of C-R and PH-R. The moisture content of JFF-R imported from Peru (JFF-R-P) was 70.3%, which was higher than that of JFF-R imported from China (JFF-R-C) (67.4%), while was lower than that of JFF-R imported from Indonesia (JFF-R-I) (83.3%). However, the salinity of JFF-R-P was 13.6%, which was lower than that of JFF-R-C, while was higher that of JFF-R-I (1.8%). The moisture contents and salinities of the other fish roes were 80.4% and 3.2%, respectively, for capalin roe, and 65.4% and 20.0%, respectively, for Pacific herring roe. According to the results of pH, volatile basic nitrogen content, heavy metal content, viable cell count and coliform group, the fish roes could be used as sanitary sources for preparation of seasoned JFF-R. The major fatty acids of fish roes were 16:0 (27.8-30.5%), 18:1n-9 (7.2-8.0%), 20:5n-3 (5.6-8.2%) and 22:6n-3 (22.0-25.6%) in JFF-R, and 16:1n-7 (6.7-9.3%) as well as these fatty acids in C-R and PH-R. Total amino acid contents of fish roes ranged from 9.44 g/100 g to 10.39 g/100 g and their major amino acids were aspartic acid, glutamic acid, leucine and lysine. The mineral content of JFF-R were higher than those of the other fish roes expected for zinc of JFF-R-I. According to the results of sensory evaluation, the color and texture of JFF-R-P were superior to those of the other fish roes. No difference was, however, found in flavor, among JFF-R-P and the other fish roes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.3
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• pp.380-388
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• 2005

Lipid characteristics of 6 species of fish frame (armored weasel-fish, AW; chum salmon, CS; spanish mackerel, SM; common mackerel, CM; conger eel, CE and skipjack tuna, ST) were studied by determining total lipid (TL) contents, lipid classes, and fatty acid composition. The highest yield of bone was obtained from ST frame (64.2%), followed by CS frame (57.9%), CE frame (54.6%), A W frame (41.6%), SM frame (41.7%), and CM frame (32.6%). The highest neutral lipid content was also found in total lipid (TL) from SM bone (23.3 g/100 g), followed by TL from CE bone (21.5 g/100 g), CS bone (16.0 g/100 g), and CM bone (15.5 g/100 g), while those from ST and A W bones were 7.2 g/100 g and 0.4 g/100 g, respectively. The prominent lipid classes of neutral lipids (NL) from all fish bones and muscles were triglyceride (TG), however, which was much lower in AW than in other fishes. The percentages of EPA and DHA in NL from fish bone were in the descending order of CS (29.3%), ST (27.1%), AW (27.0%), CM (25.7%), SM (21.6%), and CE (14.9%). Based on the lipid characteristics, the CS frame was the best resource for extraction of a functional lipid.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.6
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• pp.847-854
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• 2015

The objective of this study was to determine the effects of graded inclusions of wheat bran (0%, 9.65%, 48.25% wheat bran) and two growth stages (from 32.5 to 47.2 kg and 59.4 to 78.7 kg, respectively) on the apparent ileal digestibility (AID), apparent total tract digestibility (ATTD) and hindgut fermentation of nutrients and energy in growing pigs. Six light pigs (initial body weight [BW] $32.5{\pm}2.1kg$) and six heavy pigs (initial BW $59.4{\pm}3.2kg$) were surgically prepared with a T-cannula in the distal ileum. A difference method was used to calculate the nutrient and energy digestibility of wheat bran by means of comparison with a basal diet consisting of corn-soybean meal (0% wheat bran). Two additional diets were formulated by replacing 9.65% and 48.25% wheat bran by the basal diet, respectively. Each group of pigs was allotted to a $6{\times}3$ Youden square design, and pigs were fed to three experimental diets during three 11-d periods. Hindgut fermentation values were calculated as the differences between ATTD and AID values. For the wheat bran diets, the AID and ATTD of dry matter (DM), ash, organic matter (OM), carbohydrates (CHO), gross energy (GE), and digestible energy (DE) decreased with increasing inclusion levels of wheat bran (p<0.05). While only AID of CHO and ATTD of DM, ash, OM, CHO, GE, and DE content differed (p<0.05) when considering the BW effect. For the wheat bran ingredient, there was a wider variation effect (p<0.01) on the nutrient and energy digestibility of wheat bran in 9.65% inclusion level due to the coefficient of variation (CV) of the nutrient and energy digestibility being higher at 9.65% compared to 48.25% inclusion level of wheat bran. Digestible energy content of wheat bran at 48.25% inclusion level (4.8 and 6.7 MJ/kg of DM, respectively) fermented by hindgut was significantly higher (p<0.05) than that in 9.65% wheat bran inclusion level (2.56 and 2.12 MJ/kg of DM, respectively), which was also affected (p<0.05) by two growth stages. This increase in hindgut fermentation caused the difference in ileal DE (p<0.05) to disappear at total tract level. All in all, increasing wheat bran levels in diets negatively influences the digestibility of some nutrients in pigs, while it positively affects the DE fermentation in the hindgut.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.2
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• pp.100-108
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• 2010

This study was conducted to characterize the nutrion of commercial Kwamegi, a Korean traditional food made from semi-dried Pacific saury, Cololabis saira. The ratios of saturated and monoenoic fatty acids to polyenoic fatty acids in commercial Kwamegi ranged from 0.52-0.75 and 1.01-1.53, respectively. The major fatty acids in commercial Kwamegi were 16:0 (9.1-14.2%), 20:1n-9 (8.6-16.1%), 22:1n-9 (15.7-22.1%), and 22:6n-3 (11.0-18.0%). The total amino acid content of commercial Kwamegi ranged from 27.10-33.19 g/100 g. The major amino acids in commercial Kwamegi were aspartic acid (11.8-13.0%), glutamic acid (14.3-16.0%), leucine (7.8-8.5%), and lysine (7.5-9.0%), which accounted for more than 41% of the total amino acid content. The mineral content of commercial Kwamegi ranged from 0.7-4.3 mg/100 g for zinc, 279.6-466.3 mg/100 g for potassium, 41.7-128.3 mg/100 g for calcium, 38.8-77.8 mg/100 g for magnesium, and 224.3-348.4 mg/100 g for phosphorus. These results suggest that commercial Kwamegi is a superior food in terms of nutrition and health.

• Korean Journal of Materials Research
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• v.21 no.6
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• pp.303-308
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• 2011

The effect of heat treatment on the micro-structures and the mechanical properties of 0.002% boron added low carbon steel was investigated. The tensile strength reached the peak at about $880-890^{\circ}C$ with the rising quenching temperature and then the hardness decreased sharply, but the tensile strength hardly decreased. The tensile and yield strength decreased and the total elongation increased with a rising tempering temperature, but the tensile and yield strength sharply fell and the total elongation prominently increased from above a $400-450^{\circ}C$ tempering temperature. Tempered martensite embrittlement (TME) was observed at tempering condition of $350-400^{\circ}C$. In the condition of quenching at $890^{\circ}C$ and tempering at $350^{\circ}C$, the boron precipitates were observed as Fe-C-B and BN together. The hardness decreased in proportion to the tempering temperature untill $350^{\circ}C$ and dropped sharply above $400^{\circ}C$ regardless of the quenching temperature.

• Journal of Korea Society of Industrial Information Systems
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• v.27 no.6
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• pp.127-140
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• 2022

With the recent development of the ICT (information and communication technology), the revolution of the industry has moved on from the third industry to the fourth. There is no doubt that the companies would not survive in the future without adopting these technologies. The purpose of this research is to analyze the intellectual structure of the internet of things(IoT) literature for the Industry 4.0 to suggest a better insight for the field. The data for this research is extracted from the Web of Science database. Total of 1,631 documents and 72,754 references are used for the research with the analysis program CiteSpace. Author co-citation analysis is used to analyze the intellectual structure and performed clustering, timeline and burst detection analysis. We identified 12 sub-areas of IoT for the Industry 4.0 which are 'Supply Chain', 'Digital Twin', 'Smart Manufacturing System' and etc. Through the timeline analysis we can find out which clusters will increase or decrease its reputation. As concluding remarks, limitations and further research suggestions are discussed.

• Fisheries and Aquatic Sciences
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• v.13 no.4
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• pp.350-353
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• 2010

This study demonstrated that cryopreserved semen from dead fish can be used for seedling production. Yellow croakers, Larimichthys polyactis, were killed and stored at temperatures of $20^{\circ}C$ or $0^{\circ}C$ for 6 hours. At 2 hour intervals, semen from these fish was collected using abdominal pressure and evaluated for spermatozoa motility and semen cryopreservation. Semen collected after 6 hours from dead fish stored at $0^{\circ}C$ could be cryopreserved and attained fertilization and hatching rates of $15.0{\pm}1.2%$ and $14.8{\pm}1.6%$, respectively. This study suggests that germ cells such as the semen of dead fish can be cryopreserved and utilized in the restoration of a species.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.569-576
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• 2011

Proximate and fatty acid compositions in muscle tissue were studied in 14 species of coastal and offshore fishes in Korea. Lipid content ranged from 0.57 to 10.5% and was higher in migratory and reef dwelling fishes than in demersal fishes. Protein content ranged from 14.4 to 20.3% and moisture content ranged from 72.4 to 81.8% in all fish samples. There was a negative correlation between lipid and moisture content in all fish samples (r= -0.90, P<0.001). The prominent fatty acids were 16:0, 22:6n-3 (docosahexaenoic acid, DHA), 18:1n-9, 20:5n-3 (eicosapentaenoic acid, EPA), 16:1n-7, 18:0 and 18:1n-7. Most demersal fishes contained considerably higher amounts of 20:4n-6 and/or 22:5n-3 compared with migratory and reef dwelling fishes. The proportion of total polyunsaturated fatty acid (PUFA), including DHA and EPA, was higher in demersal fishes (38.6-54.0%) than in migratory and reef dwelling fishes (23.5-35.2%).