• Korean Journal of Environment and Ecology
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• v.24 no.2
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• pp.93-100
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• 2010

The Taeanhaean National Park is the only seashore national park in Korea. To investigate the vegetation structure and characteristics of representative four islands such as Oedo, Janggodo, Godaedo and Gauido in Taeanhaean National Park, sixteen plots(size is $100mm^2$) were set up, and four plots were set up in each island. In the result of vegetation structure analysis of each island, Oedo and Janggodo was dominated by Pinus thunbergii community, and Godaedo was dominated by P. thunbergii-P. densiflora community and Gauido was dominated by Carpinus turczaninovii-P. densiflora community. But according to the physical environment of each island, there was a subtle difference in species composition even though the same P. thunbergii or P. densiflora community. The analysis of ordination and similarity turned out that the degree of similarity was lowest(6.58%) between Oedo and Gauido. The analysis result of species diversity and number of individuals shows that Gauido had high species diversity (2.7183) than the other islands.

• Journal of Environmental Science International
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• v.24 no.4
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• pp.393-401
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• 2015

Rainfall-runoff model of Jeju Oedo Stream was used to compute the optimal unit hydrograph by HEC-HMS model that reflecting on watershed characteristics. Each rainfall event was comparatively analyzed with the actual flow measurement using Clark, Snyder and SCS synthetic methods for derived unit hydrograph. Subsequently, the null hypothesis was established as p-value for peak flow and peak time of each unit hydrograph by one-way ANOVA(Analysis of variance) was larger than significance level of 0.05. There was no significant difference in peak flow and peak time between different methods of unit hydrograph. As a result of comparing error rate with actual flow measurement data, Clark synthetic unit graph best reflected in Oedo Stream as compared to other methods, and error rate of Clark unit hydrograph was 0.02~1.93% and error rate at peak time was 0~2.74%.

• Korean Architects
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• s.576
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• pp.108-113
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• 2017

• Journal of the Korean Geotechnical Society
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• v.17 no.2
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• pp.41-49
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• 2001

본 연구에서는 2단계 확정예정부지의 일부 원지반에서 수행된 CPTu(piezocone penetration test)와 DMT(dilatometer) 및 실내시험 결과를 바탕으로 흙의 분류, 비배수전단강도 그리고 압밀계수 등의 공학적 특성을 살펴보았다. CPTu와 DMT를 이용한 흙의 분류 결과, 점토층 사이에 얇게 산재한 샌드심(sand seam)층을 보다 정확하게 판정할 수 있었다. 삼축압축시험의 비배수 강도($S_{u}$ )를 기준으로 산정한 콘계수는 CPTu의 경우 $N_{k}$ =18.2를, DMT의 경우 Roque(1988)의 제안식을 이용한 $N_{c}$=6.35로 추정한 비배수전단강도가 비교적 일치하는 것으로 나타났다. 또한 CPTu와 DMT를 이용한 수평압밀계수는 비교적 근사한 것을 알 수 있었다. 그러나, 해성점토사이에 실트, 샌드심이 존재하는 실트질 지반에서의 수평압밀계수가 연직압밀계수보다 상당히 크며, 압밀계수비($C_{h(Oedo, CPTu, DMT)}$ /$C_{v Oedo}$ )는 4.3~10.2로 큰 차이를 보이고 있다.

• Journal of Environmental Science International
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• v.24 no.4
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• pp.403-414
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• 2015

This study is daytime and nighttime runoff image data caused by heavy rain on May 27, 2013 at Oedo Water Treatment Plant of Oedo-Stream, Jeju to compute runoff by applying Surface image velocimeter (SIV) and analyzing correlation according to current. At the same time, current was comparatively analyzed using ADCP observation data and fixed electromagnetic surface current meter (Kalesto) observed at the runoff site. As a result of comparison on resolutions of daytime and nighttime runoff images collected, correlation coefficient corresponding to the range of 0.6~0.7 was 6.8% higher for nighttime runoff image compared to daytime runoff image. On the contrary, correlation coefficient corresponding to the range of 0.9~1.0 was 17% lower. This result implies that nighttime runoff image has lower image quality than daytime runoff image. In the process of computing current using SIV, a rational filtering process for correlation coefficient is needed according to images obtained.

• Journal of Korean Elementary Science Education
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• v.37 no.3
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• pp.323-338
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• 2018

The aims of this study are to develop the STEAM program focused '3D printing for respiratory system' and to ascertain its influence on elementary student's science process skills, creative problem solving abilities and scientific interest. The developed STEAM program was applied to 5th grade students of O elementary school located in J city. As a result of applying the STEAM program, the experimental group of the STEAM program class improved significantly in creative problem solving abilities and scientific interest than the control group of the theoretical class. The result of learner satisfaction survey of the STEAM program was high. Meanwhile, there was no significant difference in science process skills between the two groups. Therefore, the STEAM program class with the theme of '3D printing for respiratory system' could be meaningful works to encourage students' interest as well as their creative problem solving ability and scientific interest. In future, continuous and systematic studies on STEAM programs focused on 'structure and function of our body' are needed for elementary students' cognitive and affective developments.

• Journal of Environmental Science International
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• v.26 no.4
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• pp.411-420
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• 2017

This research aims at comparing the accuracy of flood discharge estimation. For this, we focused on the Oedo watershed of Jeju Island and compared flood discharge by analyzing the values as follows: (1) the concentration of the lumped model (HEC-HMS) and distributed model (Vflo), and (2) the in-situ data using Fixed Surface Image Velocimetry (FSIV). The flood discharge estimation from the HEC-HMS model is slightly larger than the Vflo model results. This result shows that the estimations of the HEC-HMS are larger than the flood discharge data by 4.43 to 36.24% and that of the Vflo are larger by 8.49 to 11%. In terms of the error analysis at the peak discharge occurrence time of each mapping, HEC-HMS is one hour later than the measured data, but Vflo is almost the same as the measured data.

• Journal of Environmental Science International
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• v.24 no.4
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• pp.415-424
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• 2015

As global warming has accelerated to weather in recent years, and The frequent floods are creating heavy rains and typhoons followed by considerable damage in Jeju. This study estimated design flood discharges and flood stage in Jeju, considering climate change in connection with RCP scenario, the 5th IPCC Report recently published. It also analyzed the period which might be subject to the risk of flooding in downstream of Oedo Stream. As a result, it has analyzed that there might be a risk of flooding when there were 80 years or more rainfall events in 35 years that rainfall would have increased by 10%, 69 years that 100 years or more heavy rain and rainfall would have increased by 20%, and 104 years that 100 years or more heavy rain and rainfall would have increased by 20%. It is expected that this study results of rainfall increasing trend caused by climate change will be helpful to minimize the damage of floods which will secure the future of Jeju.

• Journal of Korean Elementary Science Education
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• v.39 no.1
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• pp.84-99
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• 2020

The purpose of this study is to develop a STEAM program using technological pedagogical and content knowledge (TPACK) model to effectively utilize technology to solve the difficulties in the teaching of 'structure and function of our body' unit in the primary science curriculum and to confirm the effect on the academic achievement, creative problem solving ability and scientific interests of elementary students. The program was developed as the STEAM program of the 8th class by utilizing the construction knowledge of the TPACK model. The developed program was applied to 29 experimental group students in 5th grade. And the textbook-oriented circulatory system learning program was applied to 29 5th graders in the same school. As a result of the application of the program, the experimental group showed significant improvement over the comparison group in its creative problem solving ability and scientific interests, and the satisfaction of the class was also high. This caused a positive effect on students because the process of self-directing information about the circulatory system using smart devices, making outputs creatively using 3D printers, and presenting them through role play using produced outputs.

• Journal of Environmental Science International
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• v.23 no.4
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• pp.585-594
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• 2014

This study Analyzed four of seven runoffs which had happened in 2012 in comparison with the runoffs shown in Kalesto data, using the fixed surface image velocimetry (FSIV) installed at Oedo stream, Jeju Island. As a result of identifying a runoff curve graph, it was analyzed that the flood runoffs calculated with two observation devices were almost equivalent. As the differences in peak flows were 10 $m^3/s$, 0.7 $m^3/s$ and 3 $m^3/s$, the very similar result values were calculated. Even though there were errors in RMSE(Root Mean Square Error) made by two observation devices according to the degree of the peak flow, the values of $R^2$ by flood event were 0.89, 0.87, 0.86 and 0.82, showing the result values almost close to 1. Therefore, there was a very high correlation in flood runoffs calculated with two observation devices. This research method was considered to be a very suitable method to measure unexpected flood runoffs which could happen in the island area such as Jeju island during bad weather.