• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.11a
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• pp.159-166
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• 2004

The beach, a margin between the sea and the land, is an extremely dynamic zone, for it is here that the motion of the sea interacts with the sediment, rock of the land or the artificial barriers. In order to prohibit or retard erosions due to the extreme Typhoon or storm induced waves, man has constructed these of temporary or more permanent nature, but they caused problems of other erosions from the secondary effect of them and a bad influence on the seascape. In considering the energy available to accelerate sediment transport and erosion in the surf zone, where the waves are broken, and offshore beyond the breaker line, the wave height and the wave period should be taken account. Hence, we tried to present an applicability of the submerged artificial Bio-reefs analyzing waves by a numerical model such that they could reduce the wave power without the secondary effect and restoration of marine ecologies. A new technique of beach preservation is by artificial reefs with artificial and/or natural kelps or sea plants. By engineering the geometry of the nearshore reef, the wave attenuation ability of the feature can be optimized Higher, wider and longer reefs provide the greatest barrier against wave energy but material volumes, navigation hazards, placement methods and other factors require engineering considerations for the overall design of the nearshore reefs.

• Korean Journal of Community Nutrition
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• v.15 no.1
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• pp.50-60
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• 2010

The purpose of this study was to conduct nutrition education using animations for the establishment of proper eating habits among elementary school students and to evaluate its effectiveness. The subjects of this study were two classes of fourth grade students in an elementary school located in Daegu-city. There were 29 students in each class. One class, the "nutrition-education" group, received nutrition education; the other class, the "no-education" group, did not receive the education. After completing the eight nutrition lessons, the effectiveness of the education was analyzed by measuring changes in the nutrition knowledge, eating habits and food preferences of the nutrition-education group vs. the no-education group. Before nutrition education, there was no significant difference between the two groups in terms of nutrition knowledge. However, after the nutrition education, the nutrition-education group's nutrition knowledge was significantly improved, compared to that of the no-education group (p < 0.001). Following education, the nutrition-education group's responses to the "eating habit" item, "I eat fruits every day," were significantly more positive, compared to the responses of the no-education group (p < 0.01). However, for the ten food groups listed as food preferences, except for fish and shellfish (p < 0.05), there was no significant difference in the responses of the two groups. Following the education, the nutrition-education group showed significantly increased preferences for 12 food items (red beans, mackerels, yellow corvinas, dried laver, kelps, radish, lettuce, pears, kiwi fruits, plums, grapes and sweet drinks made from fermented rice) out of 112 items, compared to the selected preferences of the no-education group. After education, 75.9% of the students in the nutrition-education group indicated changes in their eating habits, and 89.6% of them answered that the nutrition education helped them change their eating habits. The most helpful medium for changing their eating habits was animations (31.0%), followed by songs (20.7%) and lectures (17.2%). As a result of this study, after completing the nutrition education, students in the nutrition-education group showed significant changes in food preferences, and their level of nutrition knowledge was significantly increased. However, their eating habits did not actively change. Therefore, in order to establish proper eating habits, a longer period of consistent education is required, using various educational media and learning methods such as extracurricular activities and discretionary activity programs.

• Journal of Ecology and Environment
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• v.45 no.4
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• pp.203-217
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• 2021

Background: Sea turtles, which are globally endangered species, have been stranded and found as bycatch on the Korean shore recently. More studies on sea turtles in Korea are necessary to aid their conservation. To investigate the spatio-temporal occurrence patterns of sea turtles on the Korean shore, we recorded sampling locations and dates, identified species and sexes and measured sizes (maximum curved carapace length; CCL) of collected sea turtles from the year 2014 to 2020. For an analysis of diets through stomach contents, we identified the morphology of the remaining food and extracted DNA, followed by amplification, cloning, and sequencing. Results: A total of 62 stranded or bycaught sea turtle samples were collected from the Korean shores during the study period. There were 36 loggerhead turtles, which were the dominant species, followed by 19 green turtles, three hawksbill turtles, two olive ridley turtles, and two leatherback turtles. The highest numbers were collected in the year 2017 and during summer among the seasons. In terms of locations, most sea turtles were collected from the East Sea, especially from Pohang. Comparing the sizes of collected sea turtles according to species, the average CCL of loggerhead turtles was 79.8 cm, of green turtles was 73.5 cm, and of the relatively large leatherback turtle species was 126.2 cm. In most species, the proportion of females was higher than that of males and juveniles, and was more than 70% across all the species. Food remains were morphologically identified from 19 stomachs, mainly at class level. Seaweeds were abundant in stomachs of green turtles, and Bivalvia was the most detected food item in loggerhead turtles. Based on DNA analysis, food items from a total of 26 stomachs were identified to the species or genus level. The gulfweed, Sargassum thunbergii, and the kelp species, Saccharina japonica, were frequently detected from the stomachs of green turtles and the jellyfish, Cyanea nozakii, the swimming crab, Portunus trituberculatus, and kelps had high frequencies of occurrences in loggerhead turtles. Conclusions: Our findings support those of previous studies suggesting that sea turtles are steadily appearing in the Korean sea. In addition, we verified that fish and seaweed, which inhabit the Korean sea, are frequently detected in the stomach of sea turtles. Accordingly, there is a possibility that sea turtles use the Korean sea as feeding grounds and habitats. These results can serve as basic data for the conservation of globally endangered sea turtles.