• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.5
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• pp.344-351
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• 2010

Uncertainty analysis on the net flow discharge (NFD) influencing the long-term material transport and the simulation results of the salinity and COD concentration distribution using the MIKE21 diffusion model in Gyeonggi bay and Han-River estuary is carried out. The NFD flowing the Gyodongdo - Seokmodo channel via the North channel of Ganghwado is estimated about 97% of the total NFD and the NFD of the Yeomha channel is estimated as only $2.5{\sim}3.0%$. On the other hand, the uncertainty defined as the difference by the different time-scale data input is analysed by the comparison of the model simulation result of the salinity and COD concentration distribution. One is computed based on the daily river flow data, and the other is computed based on the monthlymean river flow data. The results show that the salinity and COD concentration differences are about -10~20 psu and ${\pm}1.0\;mg/L$ during the summer season having a high flow discharge in Yeomha channel, respectively. The difference is clearly negligible in the open sea area.

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.4
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• pp.1-9
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• 2013

The "Historic city Preservative law" was legislated for the preservation of cultural properties and enacting regulations of managing the environment around them in 2004. This law was revised to "Historic city Preservative and Development law" in 2012, and specified the criteria for permissible behaviors in the preservative district. Therefore, this paper focused on the ancient capital Gyeongju and developed a comprehensive system for evaluating the value of the ancient historic district based on Analytic Hierarchy Process (AHP). Through the evaluation of the ancient historic districts, which are the pilot project districts in the "Gyeongju Ancient Capital Preservation Plan", some preferential projects were objectively proposed. As a result, according to the evaluation among 10 ancient historic districts in Gyeongju, Daereungwon got a score of 78.34, which is the highest among 7 special preservation districts. On the other side, the Gyo-dong area got a score of 76.14, the highest among 3 historic and cultural environmental districts. Finally, for the preservation and development of Gyeongju, some efficient preservation and development plans were objectively proposed for the pilot project districts in the "Gyeongju Ancient Capital Preservation Plan".

• Education of Primary School Mathematics
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• v.24 no.4
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• pp.175-187
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• 2021

The purpose of this study is to investigate the effects of solving multi-strategic mathematics problems on mathematical creativity and attitudes of the 6th grade students. For this study, the researchers conducted a survey of forty nine (26 students in experimental group and 23 students in comparative group) 6th graders of S elementary school in Seoul with 19 lessons. The experimental group solved the multi-strategic mathematics problems after learning mathematics through mathematical strategies, whereas the group of comparative students were taught general mathematics problem solving. The researchers conducted pre- and post- isomorphic mathematical creativity and mathematical attitudes of students. They examined the t-test between the pre- and post- scores of sub-elements of fluency, flexibility and creativity and attitudes of the students by the i-STATistics. The researchers obtained the following conclusions. First, solving multi-strategic mathematics problems has a positive impact on mathematical creativity of the students. After learning solving the multi-strategic mathematics problems, the scores of mathematical creativity of the 6th grade elementary students were increased. Second, learning solving the multi-strategy mathematics problems impact the interest, value, will and efficacy factors in the mathematical attitudes of the students. However, no significant effect was found in the areas of desire for recognition and motivation. The researchers suggested that, by expanding the academic year and the number of people in the study, it is necessary to verify how mathematics learning through multi-strategic mathematics problem-solving affects mathematical creativity and mathematical attitudes, and to verify the effectiveness through long-term research, including qualitative research methods such as in-depth interviews and observations of students' solving problems.

• Korean Journal of Environment and Ecology
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• v.36 no.1
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• pp.1-29
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• 2022

This study surveyed the Mt. Teomo·Hyeolgu and surrounding areas in Ganghwa Island, located in Ganghwa-gun, Incheon, to identify vascular flora and alien plants to be used as basic data for systematic management of the remarkable plants and biodiversity conservation. The survey was carried out 13 times from March 2019 to October 2020. The identified vascular flora of Mt.Teomo·Hyeolgu was 101 families, 321 genera, 517 species, 13 subspecies, 38 varieties, 5 forms, and 573 taxa. They accounted for about 12.35% of a total of 4,641 taxa of vascular plants in Korea. The identified Northern lineage plants, endemic plants, and rare plants on the Korean Peninsula as designated by IUCN were 68 taxa, 10 taxa, and 9 taxa, respectively. 69 taxa were classified as floristic target species. Three taxa, including Maui sedge [Carex thunbergii var. appendiculata (Trautv. & C.A.Mey.) Ohwi] were identified s Class IV and 14 taxa, including Violet Stanavoi clematis (Clematis fusca var. violacea Maxim.) were identified as Class III. The naturalized plants that appeared in the study site were 63 taxa, including daisy fleabane [Erigeron annuus(L.) Pers.], common ragweed [Ambrosia artemisiifoliaL.] and Canadian fleabane [Conyza canadensis(L.) Cronquist]. The above three species were found to have spread throughout Ganghwa Island and surrounding areas such as Seokmo Island, Gyodong Island, and Gimpo city. As introduced disturbing plants like prickly lettuce [Lactuca scariola L.], bur cucumber [Sicyos angulatus L.] and field dock [Rumex acetosella L.] have been newly reported in the Mt. Teomo·Hyeolgu area, mid- to long-term conservation measures should be established for native plants, such as remarkable plants, and also management measures like physical removal should be prepared at an early stage.