• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.17-17
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• 2020

일반적인 연안 해역에서 창조지속시간과 낙조지속시간은 거의 동일한 수준을 보여 조위곡선은 대칭적인 형태를 띠게 된다. 그러나 M4분조나 MS4분조와 같은 천해조가 발달된 해역에서는 그 모체가 되는 M2분조나 S2분조와의 상대적인 위상차에 따라 조위곡선이 비대칭적인 형상을 띠기도 한다. 창조지속시간이 길 경우 낙조시 최대조류속이 크게 되는 낙조우세가 형성되는 반면 낙조지속시간이 길 경우에는 반대로 창조우세가 형성된다. 소류사의 움직임은 유속의 6승에까지 비례하므로 이러한 최대조류속 차이에 따라 창조우세 또는 낙조우세 해역에서 소류사 이동량에는 큰 차이가 발생할 수 있다. 감조하천의 경우 상류로 갈수록 창조우세화하는 것이 일반적인 것으로 알려져 있으며 국내에서는 금강을 비롯한 군산해역이 대표적이다. 창조우세인 군산해역과 반대로 영산강하구 및 목포해역의 경우 낙조우세를 보이고 있는데, 그 근원은 황해에서의 순환특성과 함께 목포해역 인근의 드넓은 조간대에 기인하는 것으로 추정하고 있다. 특히 인접한 무안만에서는 낙조지속시간이 창조지속시간에 비해 2시간 이상 짧아 국내에서 가장 심한 수준의 낙조우세를 보이고 있으며, 영산강하구 낙조우세의 근원으로 평가되고 있다. 한편 조간대가 발달된 해역은 천해조 생성에 따라 낙조우세 경향이 있음과 관련하여 Kang and Moon(2001)은 조간대가 조석파의 전파와 천해조 발생에 미치는 영향성에 대하여 수치실험을 통해 연구한 결과 무안만의 낙조우세는 조간대의 발달에 기인함을 재확인한 바 있다. 따라서 낙조 우세를 수치모형을 통해 재현하기 위해서는 조간대 모의가 필수적임과 동시에 낙조우세를 재현하기 위해서는 천해조 개방경계 설정이 필요하다고 알려져 있다. 또한 이렇게 천해조가 발달된 하구에서 조석비대칭 현상은 퇴적물 이동에 직접적인 영향을 미치게 되는데 Kang et al.(2002)은 소류사 및 부유사 이동에서 이러한 영향성에 대한 연구를 수행한 바 있다. 그 결과 천해조가 발달된 이러한 해역에서 퇴적물 이동과 관련된 수치모의시 M2분조와 같은 천문조 경계조건에 부가하여 M4분조의 천해조까지 포함시킬 것을 제안한 바 있다. 이와 같이 하구역에서는 천해조 발달로 인해 조석비대칭이 두드러지게 발달되어 있는 경우가 많으며, 감조하천 상류로 갈수록 비대칭은 더욱 심화되는 경향이 있다. 따라서 감조하천 하류부에서 조석을 고려한 경계조건을 부여하여 하천의 흐름양상을 수치적으로 모의할 경우 천해조가 발달된 하구역에서는 천해조가 포함된 경계조건은 필수적이라 할 수 있다.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.120-120
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• 2021

2020년 8월 7일부터 8월 8일까지 호우는 용담댐, 섬진강댐, 합천댐 하류 유역의 막대한 침수피해를 일으켰다. 이들 다목적 댐 유입량의 신뢰도 높은 모의는 홍수기 댐 운영 및 하류하천의 홍수 해석에 필수다. 여기서는 일 유출 모의 기반으로 개발된 ONE 모형을 10분 단위, 1시간 단위로 적용한 결과를 제시하고자 한다. 보통 홍수모의는 사상별로 실시하지만, 여기서는 1월1일부터 12월 31일까지 연속으로 모의한 결과에서 해당 홍수사상 결과를 제시하였다. 3개 다목적 댐의 홍수사상은 8월6일부터 8월 10일까지 5일간으로 설정하였다. 유역면적은 용담댐, 섬진강댐, 합천댐, 각각 930km², 763km², 925km², 총강우량은 각각 490.7mm, 451.9mm, 452.4mm, 첨두유입량은 10분 단위는 각각 4,872.7m³/s, 3,533.7.0m³/s, 2,776.0m³/s, 1시간 단위는 각각 4,394.9m³/s, 3,401.8m³/s, 2,745.6m³/s, 총유입량은 각각 3억8,836만m³, 3억1,324만m³, 3억2,816만m³였다. 첨두유입량 상대오차가 0일 때의 매개변수로 모의한 결과를 제시하며, 총유입량 상대오차(Vq), R², RMSE, NSE 등으로 평가하였다. 용담댐 결과는 10분 단위 경우 최대면적강우량 7.3mm, 첨두유입량 4,872.4m³/s, 총유입량 3억 8,138만m³, Vq 1.9%, R² 0.968, RMSE 207.347, NSE 0.978였고, 1시간의 경우 최대면적강우량 29.6mm, 첨두유입량 4394.9m³/s, 총유입량 4억157만m³, Vq -8.4%, R² 0.970, RMSE 186.962, NSE 0.982였다. 섬진강댐 결과는 10분 단위 경우 최대면적강우량 9.2mm, 첨두유입량 3,533.3m³/s, 총유입량 2억7,223만m³, Vq 18.4%, R² 0.885, RMSE 808.296, NSE 0.925였고, 1시간의 경우 최대 면적강우량 37.9mm, 첨두유입량 3401.6m³/s, 총유입량 2억7,029만m³, Vq 13.7%, R² 0.907, RMSE 285.544, NSE 0.936였다. 합천댐 결과는 10분 단위 경우 최대면적강우량 5.5mm, 첨두유입량 2,776.2m³/s, 총유입량 3억3,667만m³, Vq -2.7%, R² 0.941, RMSE 191.896, NSE 0.965였고, 1시간의 경우 최대면적강우량 17.0mm, 첨두유입량 2,746.7m³/s, 총유입량 3억1,333만m³, Vq 4.5%, R² 0.965, RMSE 140.739, NSE 0.981였다. 이상 ONE 모형으로 10분, 1시간 단위의 댐 홍수 유입량 모의결과는 높은 신뢰도를 나타냈다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.6D
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• pp.623-629
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• 2010

Recently, the Shield TBM (Tunnel Boring Machine) construction method is used gradually to increase at the Tunnel Constructin site. However the design and application of the Shield TBM were carried out without sufficient investigation of the ground conditions in the construction site. Due to insufficient understanding to the corresponding equipment is frequently occurring unexpected construction cost and extension of a construction period. The most suitable alternative construction method was determined by analyzing tunneling rate, duration, construction cost of shield machine and tunneling data of alternative method. The result of the case study is suggested as follows. First, the accurate soil exploration on the construction site should be preceded to prevent from tunneling stoppage and schedule delay. Second, the most suitable selection of the shield machine to the ground conditions of the construction site should be executed based on the investigation. Third, the best alternative method for boring of hard rock section is 'hard rock blasting after open cut and cover method'.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1D
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• pp.79-87
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• 2010

The urban street has been escaped from functional and uniformed arrangement for merely movement to the space which can take the role of cozy and familiar culture. Therefore I tried to prepare a plan for the wide roads having streetscape which reveal area's identity as well as coziness and convenience by grasping the problem and its solution through analysing and deducing various elements with the subject of streetscape among urban landscape components, especially composing wide road's streetscape. First of all, this study made a simulation by deducing components of wide road's streetscape and controlling them with theoretical review of streetscape and consideration of wide road's local characteristic. With the evaluation on the base of them, that following four components could be the representative things of entrance part was confirmed by this study. They were familiar streetscape,symbolic scene as as an entrance gate, continuous and dynamic streetscape, and interesting and pleasant streetscape. And for the middle part, those four components could represent the wide road's streetscapeI were confirmed. They were familiar streetscape, safe and tender streetscape, pleasant and dynamic streetscape, and symbolic streetscape. It seems that the components of the streetscape obtained from the analysis of this study are utilized as reference data in the case of a future streetscape design conclusively.

• Journal of the Korean Society of Food Culture
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• v.25 no.1
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• pp.100-107
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• 2010

This study was performed to compare the dietary intake and food sources of zinc (Zn), using a database of Zn composition developed in this study, between elementary schoolchildren in a remote rural area (RA, n=58, $9.9{\pm}1.7\;yrs$) and those in an urban area (UA, n=60, $9.4{\pm}1.8\;yrs$) in Chungnam province in Korea. A dietary survey for three days by food record method was performed. All kinds of foods (n=273) consumed by subjects were collected by aliquot sampling method, and the Zn content of these foods were analyzed by wet technique. The results showed that the daily mean intakes of energy, calcium, iron, and vitamin C from diet in the RA were in the range of 49-88% of the Korean DRI (KDRI), while those in the UA were similar to or greater than the KDRI, except for calcium and iron. The daily mean intake of Zn from the RA diet was $7.0{\pm}0.5\;mg/d$ ($114.1{\pm}8.4%$ of the KDRI), and $16.0{\pm}1.0\;mg/d$ ($258.3{\pm}16.3%$ of the KDRI) in that of the UA (p<0.001). The percentage of dietary intake of Zn less than 2/3 of the KDRI was 19.0% in the RA, in comparison to 1.7% in the UA. Those in the RA consumed Zn from plant foods more often than did those in the UA (p<0.001). Beef rib stew was the food source with highest Zn amount for the total subjects, followed by beef rib meat, roasted; and beef soup w/seasoned red pepper sauce. These results showed that some children in the RA had poor Zn nutrition based upon low intakes and poor food sources of Zn, while overall, children in the UA had good Zn nutrition. Therefore, those in RAs should have their Zn nutrition improved through government policy and nutrition education.

• Journal of the Korean Society of Food Culture
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• v.25 no.3
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• pp.350-356
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• 2010

When extracts of KMG (Korean mountain ginseng) leaf tea and fermented KMG leaf tea were compared, the fermented KMG leaf tea extract showedhigher activity at each stage of density. Among the material groups, the KMG extract hadthe least profound SOD-like activity, and similar SOD-like activities were noted in the fermented KMG, KMG leaf tea, and fermented KMG leaf tea extracts. With regard to nitrite scavenging ability at a pH of 1.2, the KMG, fermented KMG, and KMG leaf tea groups exhibited similar results, and at pH 3.0, the KMG and KMG leaf tea extract groups exhibited more profound nitrite scavenging ability compared to the fermented groups. In the case of HeLa cell treatments, the KMG and fermented KMG leaf tea extracts exhibited cancer cell propagation restraint rates in excess of 30%, at a density of 1 mg/mL. And MCF-7 cells treated with fermented KMG and KMG leaf tea showedsimilar propagation restraint rates at more than 27% of cancer cells, at a density of 1 mg/mL. Among the materials, the KMG extract hadthe lowest cancer cell propagation restraint rate at 21%, and the fermented KMG leaf tea extract had the highest rate at more than 70%.

• Korean Journal of Community Nutrition
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• v.28 no.3
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• pp.235-244
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• 2023

Objectives: Based on the results from the Korean Total Diet Study (KTDS), the sodium (Na) and potassium (K) intake of Koreans were estimated and compared with intake estimates from the Food & Nutrient Database (FNDB), as in the Korea National Health and Nutrition Examination Survey (KNHANES) to verify the validity of these estimates. Methods: One hundred and thirty-four representative foods (RFs) covering 92.5% of the total food intake of Koreans were selected, and 228 pairs of corresponding 'RF x representative cooking method' were derived by reflecting the methods used mainly in terms of frequency and quantity in their cooking. RF samples were collected from three cities with a larger population size in three regions (nine cities) nationwide, and six composite samples were made for each RF, considering its regional and/or seasonal characteristics. One thousand three hundred and sixty-eight 'RF x representative cooking method' pair samples were prepared, and the Na and K contents were assessed using inductively coupled plasma atomic emission spectrometry (ICP-MS). The Na and K intake of the Korean population was estimated by linking the content with the food intake data from the 7th KNHANES. Results: The mean Na and K intake of Koreans were 2,807.4 mg and 2,335.0 mg per person per day, respectively. A comparison with the Na and K intake from KNHANES, including only RFs of KTDS, showed comparable results with less than 5% variation. While the contribution and ranking of food items to Na intake were similar between KNHANES and KTDS, there were differences in K intake. This was attributed to the large discrepancies in the K content of rice and coffee between KTDS results and the values in the 9th Revision of the National Food Composition Table used in KNHANES. Conclusions: The Na and K intake of Koreans estimated based on the KTDS, which performed nutrient analysis on samples prepared to a 'table-ready' state using foods of the representative collection, was similar and comparable with that of KNHANES. This supports the validity and usefulness of FNDB-based nutrient intake estimation at the population level. The list of nutrients studied in KTDS is expected to be expanded, allowing for intake estimation of nutrients with currently insufficient or absent information in the FNDBs in use.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.25 no.4
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• pp.97-105
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• 2020

The genus Navicula, with its notably high species diversity, is one of the most important genera of the diatom assemblages of the tidal flats. In the present study, Navicula spartinetensis was firstly observed from Yellow Sea including both of Korean and Chinese tidal flats. Morphological description was also made based on the LM and SEM observation. Samples were collected from four locations in Korea, two in October 2006, one in July 2007, and one in July 2018, and seven location in China from June to July 2018. N. spartinetensis was firstly described by Sullvian & Reimer in 1975; Cells are lanceolate with narrow valve faces, 20-30 ㎛ long, 5-6 ㎛ wide, and the density of striae is 12-13 in 10 ㎛, and the terminal raphe ending curved in the same direction. N. spartinetensis has been previously reported from Europe and South America, and the present study has expanded its distribution to the Northeast Asia. In conclusion, the diversity of Korean marine benthic diatoms is still underestimated thus extensive further study of diatom taxonomy is needed.

• Journal of Korean Academy of Dental Administration
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• v.5 no.1
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• pp.38-44
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• 2017

Little evidence has been provided on the standardization of community dental hygiene as one of the subjects of dental hygiene course. The goals of this study were to: examine the satisfaction of a dental hygiene student's in the practice program according to public health centers and explore the satisfaction factors of a dental hygiene student's in the program of public health center. Data on 105 were obtained from the undergraduate students in the university in Gyeonggi-do. As a result of satisfaction of the practice at 11 public health centers, the overall mean score was 5.3 out of 7 score. The means of satisfaction score were different cross public health centers with the 3.7 lowest and 6.8 highest score. Among the factors affecting satisfaction of the practice at public health center, 'comfortability of practice' was identified by 55.2%, followed by 'accessibility (46.7%)' and 'academic achievement (31.4%)'. Different proportions of respondents were obtained between 3rd year and 4th year students. In conclusion, this study highlighted the importance of the program of public health center for quality improvement of community oral health practice. A survey of the satisfaction of a dental hygiene student of community oral health practice is to provide evidence data as a starting point for this purpose.

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.95-103
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• 2023

This paper proposes an artificial intelligence convergence education program for teaching the main concept and principle of Support Vector Machines(SVM) at elementary schools. The developed program, based on Jeju's natural environment theme, explains the decision boundary and margin of SVM by vertical and parallel from 4th grade mathematics curriculum. As a result of applying the developed program to 3rd and 5th graders, most students intuitively inferred the location of the decision boundary. The overall performance accuracy and rate of reasonable inference of 5th graders were higher. However, in the self-evaluation of understanding, the average value was higher in the 3rd grade, contrary to the actual understanding. This was due to the fact that junior learners had a greater tendency to feel satisfaction and achievement. On the other hand, senior learners presented more meaningful post-class questions based on their motivation for further exploration. We would like to find effective ways for artificial intelligence convergence education for elementary school students.