• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.3
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• pp.198-205
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• 2019

The small yellow croaker (Larimichthys polyactis) is one of the representative high-class fish species in Korea. The catch of small yellow croaker in adjacent water fisheries has been continuously decreasing from 59,226 tons in 2011 to 19,271 tons in 2016. The small yellow croaker is caught by gillnet, stow net and bottom trawl, among which about 55~65% is caught by gillnet. For the sustainable use of small yellow croaker, the fishing power of small yellow croaker drift gillnet is very important. Therefore, the change of fishing power index were analyzed to identify the development of the vessel and gear technology that may have improved the fishing efficiency of the small yellow croaker drift gillnet fishery from 1960s to 2010s. Gross tonnage and horse power per fishing vessel was increased annually. The mesh size was 75.0 mm in the 1960s, but reduced to 60.6 mm in the 1980s and to 51.0 mm in the 2000s. In the 1960s, it was hauled out by manpower. However, the net hauler were modernized and supply rate was also increased since 1970. Due to the mechanization of the net hauler, the number (length) of used net gradually increased from 1.5 km in the 1960s to 7.5 km in the mid-1980s and to 15 km in 2010. Colour fish finders and positioning system were introduced and utilized from the mid-1980s. Surveys on the supply and upgrading of fishing equipment utilized visiting research. Therefore, the relative fishing power index in the small yellow croaker drift gillnet fishery increased from 1.0 in 1980 to 0.8 in 1970, to 1.1 in 1990, to 1.6 in 2000 and to 1.9 in 2010. The results are expected to contribute to reasonable fisheries stock management of the small yellow croaker drift gillnet fishery.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.404-415
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• 2018

This descriptive research investigates the knowledge of and attitude toward HIV/AIDS among individuals in their 20s to 40s. This study also analyzes the results of the 2011 and 2013 community health surveys to identify the factors influencing their knowledge and attitude. The study subjects were 20 to 49 years old, and the final analysis included 182,315 subjects. The collected data were analyzed through t-tests, ANOVA, correlational analysis, and multiple regression analysis. The survey results showed a high level of knowledge of HIV/AIDS, with 69.4% correct answers. Most individuals lacked knowledge regarding routes of infection, and those in their 20s had the lowest percentage of correct answers. As for attitude toward HIV/AIDS, 44.3% showed a negative attitude. The scores for knowledge and attitude toward HIV/AIDS were higher among males, unmarried individuals, individuals with a higher income, individuals with a higher level of education, individuals working in agriculture, forestry, or fishery, managers, professions that were not homemakers/unemployed, and professional soldiers. A positive correlation (r=0.27, p<0.001) was observed between knowledge and attitude. The factors influencing AIDS knowledge and attitude were gender, marital status, income level, occupation, and education level. This study confirmed that there is a difference by age group. As such, educational programs customized by age and other characteristics are expected to be more effective in enhancing knowledge and in developing a more positive attitude towards HIV/AIDS.

• Journal of Korean Historical Folklife
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• no.33
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• pp.359-384
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• 2010

The studies on Daedonggye(大同契), by this time, have been mainly researched focusing on the ruling system of country villages related to 'King(王)-local governor(守令)-noble family(士族)' in Chosun Period. The result of it is that it made a great contribution to reveal the operation of country society and substance of the ruling class but made it wholly lacking studying on the organization of Daedonggye in fishing villages especially and the social structure after the opening of ports. The residents in Noryeokdo have operated Daedonggye for about 80 years from 1925 up to now. Anyone who is a householder in Noryeokdo has been a participant in a member of it. The reason is that the participation in Daedonggye is the most basic requisite to lead the community life of the fishing village. It was investigated in this study that the residents operated their Daedonggye in what way in the 20th century and what motive made them keep it prolonged for a long time up to the 21th century.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.57 no.1
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• pp.78-91
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• 2021

This study analyzed the reproductive biology, fishing characteristics and changes in fishing business of Liparis tanakae, snailfish collected from September to March. It was the period when they were mainly caught from 2018 to 2020. The average length was generally small in September and October and was large in January and February. The average body weight was generally around 1,500 g and the average body weight in autumn was lower and in winter was higher. The sex ratio of male and female was 0.40:0.60 (��2 test, p < 0.05). The spawning period was estimated from October to February and the main spawning period was from December to February through the GSI. The egg diameter of matured staged female L. tanakae was 0.11-1.48 mm, which was the main spawning period and the relationship between body weight and fecundity was F = 1849TL0.1093 (r2 = 0.2401). The monthly catch of L. tanakae was high from November to February, the time of migrating to the coastal area. Coastal gillnet fishery showed the highest percentage of all fisheries catching Liparis spp. Liparis spp. were caught at a high rate in winter in Chungnam, Jeonbuk, Jeonnam and Gyeongnam region, and revenue and cost was increased since 2017. Assuming a situation where there is no catch of Liparis spp., the fishing profit that can be obtained was the highest in Gyeongnam region and the dependence on fishing of Liparis spp. by coastal gillnet fishery was high.

• Journal of Convergence for Information Technology
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• v.11 no.7
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• pp.278-287
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• 2021

This study was conducted to analyze with a focus on gender whether the prevalence of hyperuricemia varies depending on sitting time and high-risk drinking by occupational group. For this study, the Korea National Health and Nutrition Examination Survey data were used, and 16,366 people were selected. The chi-square independence test and logistic regression model were used as the analysis method. The prevalence and risk of hyperuricemia by sitting time were different in the 'agricultural, forestry and fishery skilled workers' only in men. On the other hand, the prevalence with high-risk drinking, both men and women showed differences in 'managers, experts and related workers' and 'office worker'. Also, only women have differences in 'service and sales workers', 'technicians, equipment, machine operation and assembly workers' and 'unemployed'. These results inform men have a higher prevalence and risk of hyperuricemia and suggest that health care policies and medical services are needed to prevent it by occupational group.

• Journal of the Korea Society of Computer and Information
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• v.27 no.3
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• pp.119-126
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• 2022

The reported risk factors for gallstone disease (GD) are old age, female sex, obesity, metabolic syndrome and migrants. Many younger adults tend to live in Jeju City, where transportations are convenient and commercial activities are active. Whereas, older people tend to live in Seogwipo City, because they engaged in fisheries and agriculture. Rates of migrants and old age could affect the prevalence of GD among residents in two regions. Therefore, the purpose of this study was to compare the GD prevalence and analyze risk factors affecting GD including residencies. A total of 13,050 subjects who visited a single health medical check-up center on Jeju Island between 2012 and 2019 were included. We performed univariate and multivariate analysis to identify risk factors for GD. The prevalence of GD among residents were 5.7% in Jeju City and 5.8% in Seogwipo City, respectively. Multivariate analysis revealed that age (P=0.008), body mass index (P=0.044), high-density lipoprotein cholesterol (P=0.006) and gamma-glutamyl transferase (P=0.013) were independent factors affecting GD. The old age, mean higher body mass index, gamma-glutamyl transferase and mean lower high-density lipoprotein cholesterol were independent risk factors affecting GD. However, residencies did not affect the prevalence of GD.

• Korean Journal of Remote Sensing
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• v.38 no.3
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• pp.299-309
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• 2022

Recently, The sea water temperature around Korean Peninsula is steadily increasing. Water temperature changes not only affect the fishing ecosystem, but also are closely related to military operations in the sea. The purpose of this study is to suggest which model is more suitable for the field of water temperature prediction by attempting short-term water temperature prediction through various prediction models based on deep learning technology. The data used for prediction are water temperature data from the East Sea (Goseong, Yangyang, Gangneung, and Yeongdeok) from 2016 to 2020, which were observed through marine observation by the National Fisheries Research Institute. In addition, we use Long Short-Term Memory (LSTM), Bidirectional LSTM, and Gated Recurrent Unit (GRU) techniques that show excellent performance in predicting time series data as models for prediction. While the previous study used only LSTM, in this study, the prediction accuracy of each technique and the performance time were compared by applying various techniques in addition to LSTM. As a result of the study, it was confirmed that Bidirectional LSTM and GRU techniques had the least error between actual and predicted values at all observation points based on 1 hour prediction, and GRU was the fastest in learning time. Through this, it was confirmed that a method using Bidirectional LSTM was required for water temperature prediction to improve accuracy while reducing prediction errors. In areas that require real-time prediction in addition to accuracy, such as anti-submarine operations, it is judged that the method of using the GRU technique will be more appropriate.

• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1047-1056
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• 2022

Sea ice, frozen sea water, in the Artic is a primary indicator of global warming. Due to its importance to the climate system, shipping-route navigation, and fisheries, Arctic sea ice prediction has gained increased attention in various disciplines. Recent advances in artificial intelligence (AI), motivated by a desire to develop more autonomous and efficient future predictions, have led to the development of new sea ice prediction models as alternatives to conventional numerical and statistical prediction models. This study aims to evaluate the performance of the two-stream convolutional long-and short-term memory (TS-ConvLSTM) AI model, which is designed for learning both global and local characteristics of the Arctic sea ice changes, for the minimum September Arctic sea ice from 2001 to 2021, and to show the possibility for an operational prediction system. Although the TS-ConvLSTM model generally increased the prediction performance as training data increased, predictability for the marginal ice zone, 5-50% concentration, showed a negative trend due to increasing first-year sea ice and warming. Additionally, a comparison of sea ice extent predicted by the TS-ConvLSTM with the median Sea Ice Outlooks (SIOs) submitted to the Sea Ice Prediction Network has been carried out. Unlike the TS-ConvLSTM, the median SIOs did not show notable improvements as time passed (i.e., the amount of training data increased). Although the TS-ConvLSTM model has shown the potential for the operational sea ice prediction system, learning more spatio-temporal patterns in the difficult-to-predict natural environment for the robust prediction system should be considered in future work.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.6
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• pp.880-889
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• 2021

The home meal replacement (HMR) market has attracted significant attention due to COVID-19 pandemic and products that utilize the combination of different processed ingredients are now being developed. In this study, Broughton's ribbed ark Scapharca broughtonii was soaked in seasoned soy sauce with the incorporation of mustard leaf Brassica juncea (M-BRA), which is known to have a unique texture as well as excellent functional properties such as antioxidation, to develop a regional specialty product. The optimal conditions for manufacturing M-BRA from the seasoned soy sauce (the sauce to be added [X₁] and the soaking time [X₂]), were examined using response surface methodology (RSM) to analyze the significance of the salinity (Y₁), amino-N content (Y₂), and overall acceptance (Y₃). The coefficient of determination (R²) between X₁-X₂ and Y₁-Y₃ were close to 1, thereby confirming the suitability of the RSM model. The optimal conditions were seasoned soy sauce addition of 140% and soaking time of 156 min. The M-BRA manufactured under these conditions exhibited superior overall acceptance compared to seasoned commercial soy sauce, which was used as a control. We expect that the market for M-BRA manufactured by combining marine and agricultural materials will expand owing to superior overall acceptance compared with commercial products.

• Korean Journal of Ecology and Environment
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• v.54 no.4
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• pp.384-389
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• 2021

This study was conducted on October 23, 2020 at the Cheongpyeong Reservoir located in Seorakmyeon, Gapyeong-gun, Gyeonggi-do, and analyzed the horizontal and vertical distribution patterns of fish based on data obtained using fishfinder. The total surface area of fishfinder survey conducted was 782,853 m², and where the water depth (WD) ranges from 10 m to 12 m is widest which 31.7% of total surface area. As a result of the heat map analysis, fish density was highest at right bank under the Gapyeong-bridge, but there was no specific pattern in horizontal distribution of fish. As a result of vertical distribution of fish analysis, 86.6% of fishes are observed at below 6 m of the fish depth (FD, distance from water surface to fish). As a result of the relative height (RH, water depth-distance from bottom to fish ratio) analysis, there was a tendency that fishes are distributed in near surface area more as the WD increased. This tendency could have various reasons such as water temperature gradient along the water depth, and further studies are required for detailed explanation.