• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.2
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• pp.193-201
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• 2021

The welding has a high proportion of the production and drying of ships or offshore plants. Non-destructive testing is carried out to verify the quality of welds in Korea, radiography test (RT) is mainly used. Currently, most shipyards adopt analog-type techniques to print the films through the shoot of welding parts. Therefore, the time required from radiography test to pass or fail judgment is long and complex, and is being manually carried out by qualified inspectors. To improve this problem, this paper covers a platform for scanning and digitalizing RT films occurring in shipyards with high resolution, accumulating them in management servers, and applying artificial intelligence (AI) technology to detect welding defects. To do this, we describe the process of designing and developing RT film scanning equipment, welding inspection information integrated management platform, fault reading algorithms, visualization software, and testing and verification of each developed element in conjunction.

• Journal of the Korean Geotechnical Society
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• v.38 no.4
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• pp.21-32
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• 2022

Steel pile foundations are widely used for offshore constructions due to their high bearing capacity and efficiency. Typically, offshore structures that have reached the end of their design life are required to be demolished. However, pile foundations are often left on site due to technical and economic limitations. The pile left on the site not only pollutes the environment, but can also cause obstacles for the construction of new structures. Therefore, research is required to completely eliminate these foundations at the site. In this study, a new type of double-wall pile foundation that can drastically reduce the pull-out load was conceptually proposed, and a series of model tests were performed to validate the performance of the double-wall pile foundation. The installation and extraction of the double-wall pile were simulated in dry sand in the model test, and the measured up-lift load was compared to that of the conventional pile. According to the result, the maximum up-lift load induced by the decommissioning of the double-wall pile was reduced by 45% when compared to the traditional pile in dense sand. This study verified the mechanism for reducing the up-lift load of the double-wall foundation and confirmed the possibility of completely decommissioning a pile that has reached the end of its nominal service life.

• Journal of Bio-Environment Control
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• v.31 no.2
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• pp.114-124
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• 2022

The Saemangeum has a dry surface characteristic with a low moisture content ratio due to the saline and silt soil, so the vegetation cover is low compared to other areas. In areas with low vegetation cover, wind erosion has a high probability of scattering dust. If the vegetation cover is increased by cultivating crops that can withstand the Saemangeum reclaimed environment, scattering dust can be reduced by reducing the flow rate at the bottom. Thus, the purpose of this study is to analyze the effect of suppressing the generation of fine dust and scattering dust by cultivating winter forage crops on the Saemangeum reclaimed land. While growing 0.5 ha of barley and 0.5 ha of triticale in Saemangeum reclaimed land, the concentration of fine dust was monitored according to agricultural work and growth stage. Changes in the concentrations of PM-10, PM-2.5, and PM-1.0 were monitored on the leeward, the windward and centering on the crop field. As a result of monitoring, PM-1.0 had little effect on crop cultivation. the concentration of PM-10 and PM-2.5 increased according to tillage and harvesting, and tillage had a higher increasing the concentration of PM-10 and PM-2.5 than that of harvesting. According to the growth stage of crops, the effect of suppressing scattering dust was shown, and the effect of suppressing scattering dust was higher in the heading stage than in the seedling stage. So, it was found that there was an effect of suppressing scattering dust other than the effect of land covering. Through this study, it was possible to know about the generation and suppression effect of scattering dust according to crop cultivation.

• Journal of Environmental Impact Assessment
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• v.31 no.4
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• pp.241-249
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• 2022

Humans and wild birds coexist in cities, where habitat fragmentation due to urbanization threatens the habitat and movement of birds. In this study, in order to identify landscape features associated with wild bird collide, we characterized landscape composition within a 500 m radius and points of wild bird carcasses in Suwon-city, South Korea. Dead birds were identified as having a Normalized Difference Vegetation Index (NDVI) of 0.3, Normalized Difference Built-up Index (NDBI) of -0.05, and Normalized Difference Water Index (NDWI) of -0.16 at the points of collide. And there were NDVI of 0.34, NDBI of -0.01, NDWI of -0.18, building height of 13.8 m, and soundproof wall length of 227.3 m within a radius of 500 m. Land cover type was dominated by grassland, used area, and bare land. In particular, the edges of urbanized areas, where apartments bordered forests, reservoirs, and golf courses, were identified as high-risk spaces. In order to minimize bird mortality risk in urban environments, the impact of changes to a vertical landscape should be reviewed from an environmental impact assessment approach. In addition, a preventive management plan that considers the temporal and spatial features that wild animals can safely avoid and adapt to in urbanized spaces should be prepared.

• Journal of Practical Engineering Education
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• v.13 no.3
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• pp.559-566
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• 2021

The aggregate gradation analysis is a study that evaluates the accuracy of a specific purpose for the aggregate gradation analysis results essential for construction-related major education. This study is to evaluate the effect of aggregate moisture content on aggregate gradation analysis. The change in the moisture content of the aggregate stored in the asphalt plant cold bin and stock piles was monitored for one year, and based on the results, a sample of aggregate with different moisture content was produced. The gradation curve for each aggregate sample was analyzed to evaluate the effect of aggregate moisture content on aggregate gradation analysis. As a result of the gradation evaluation, it was confirmed that as the moisture content increased, the particle size error for particles less than 5 mm increased in the gradation analysis of the oven-dried aggregate, and this error increased as the particle size decreased. In addition, for aggregate particles of 5 mm or more, it was confirmed that the error in gradation analysis rapidly decreased due to the increase in the moisture content. An analysis was performed on the effect of the error in gradation analysis on the management of hot-bin aggregates in asphalt plants. As a result of the analysis, it was found that the minimum aggregate size of the first hot-bin in a general asphalt plant was 2.38 mm or more, so the maximum gradation error due to the non oven-dry aggregate was less than 2%. Therefore, it seems possible to use the results of the gradation analysis of cold bin non oven-dry aggregate for quality management of asphalt mixture production.

• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.2
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• pp.90-96
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• 2022

Purpose: The purpose of this study was to investigate antimicrobial activity of extracts from shiitake mushroom against periodontopathogens and its cytotoxicity for human gingival fibroblast. Materials and Methods: Shiitake mushroom was soaked in water and acetone, and the supernatant was dried to collect its extract. The susceptibility of periodontopathogens for the extracts was investigated. Human gingival fibroblast was treated with the extracts, and the cell viability was measured CCK-8 solution. Results: The water extract from shiitake mushroom significantly reduced the growth of periodontopathogens at 2.5 mg/ml (P < 0.05). The acetone extract significantly inhibited the growth of Porphyromonas gingivalis and Tannerella forsythia at 0.32 mg/ml and Treponema denticola growth at 0.64 mg/ml (P < 0.05). The cytotoxicity of the extract was shown at a concentration of 2.5 mg/ml. The extracts with a concentration of 1.25 mg/ml appeared to be reduce cell viability after 4 h. Conclusion: The extracts of shiitake mushroom have antimicrobial activity against periodontitis-causing bacteria and relieving inflammation. Therefore, the extracts may be a candidate for preventing and treating periodontal disease.

• Journal of Internet of Things and Convergence
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• v.9 no.3
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• pp.27-33
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• 2023

In this study, it was analyzed with the dyeing pattern of Diospyros kaki Thunb (persimmon) and was tried to numerically evaluate how the dyeing pattern in silk fabrics and cells was changed by different mordants. When the dyed silk fabrics were sufficiently dried, the silk fabrics were found to have a pale yellow color. Interestingly, iron II sulfate mordant changed the color change the most, silk fabrics were dyed with a color close to brown or dark purple. For numerical analysis, 19% and 62.5% color changes could be induced by sodium tartrate plus citric acid and copper acetate, respectively. Iron II sulfate induced the greatest difference than that of untreated mordants at 88%. About 5% and 10% of Chinese hamster ovary (CHO) cells were stained by sodium tartrate plus citric acid and copper acetate, respectively. The staining effect induced by iron II sulfate was about 2.4 times higher than the staining effect by sodium tartrate plus citric acid. In previous studies, staining results have been visually confirmed. However, this results not only visually confirmed the dyeing, but also quantified the color change. In particular, if numerical results are continuously integrated into big data, any researcher will be able to easily obtain similar results even if the method, time, volume, etc. are changed. In addition, the numerical data of this study is considered to be an important basis for building a database for IoT construction and computer analysis.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.6
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• pp.681-692
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• 2017

In recent years, large-scale construction projects such as road pavement construction and new city construction have been carried out nationwide with by the expansion of social overhead facilities and base on the economic development planning, resulting in a rapid increase in artificial slope damage. The existing vegetation-based re-installation method of the slope surface greening method reveals various problems such as lack of bonding force, drying, and lack of organic matter. In this study, research was carried out using vegetation-based material and environmentally friendly soil additives, were are used in combination with natural humus, Bark compost, coco peat, and vermiculite. Uniaxial compressive strength was measured according to the mixing ratio of soil additives and the strength was analyzed. Experiments were carried out on the characteristics of the soil material to gauge the slope protection properties by using the soil compaction test method wherein the soil and the soil additive materials are mixed in relation to the soil height, the number of compaction, the compaction method (layer) and the curing condition. As a result of the experiment, excellent strength performance was demonstrated in soil additives using gypsum cement, and it satisfied vegetation growth standards by using performance enhancer and pH regulator. It was confirmed that the strength increases with the mixing of soil and soil additive, and the stability of slope protection can be improved.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.453-453
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• 2021

도시지역 비점오염원관리, 물순환 회복, 침투 및 증발산량 증가, 열섬현상 저감을 위한 주요한 방안으로 저영향개발(low impact development, LID)과 그린인프라 기법의 적용되고 있다. LID 시설은 소규모 분산형 시설로써 넓은 지역에 많고 다양한 시설들이 적용되어 시설의 개수가 많으며, 수질 및 토양 내 기성제품에 대한 센서들의 가격은 고가로 형성되어 있어 기기의 경제성 및 유지관리 등 적용하는데 제한적이다. 따라서 과거 모니터링 자료를 기반으로 오염물질들과의 상관성 분석을 통하여 계측이 어려운 항목들을 계측가능한 항목들로부터 예측 가능하며, 선정된 항목들에 대한 비용효율적인 센서를 개발하여 실시간 LID 모니터링이 가능한 비용효율적 모니터링을 개발하였다. 공주대학교 천안캠퍼스의 LID 시설들은 2013년에 조성되어 현재까지 시설이 운영되고 있으며, 5년이상의 과거 강우시 모니터링 자료들을 이용하여 오염물질 상관성 분석을 수행가능 하기에 대상지로 선정하였다. 오염물질 상관성 분석은 2013년부터 2017년도에 침투도랑에서 수행된 강우시 모니터링 자료를 활용하여 각 오염물질들의 상관성을 분석을 수행하였다. 침투도랑 내 유입되는 평균 유입수는 TSS 286.1±318.3 mg/L, BOD 22.6±39.5 mg/L, TN 8.96±5.85 mg/L, TP 1.01±1.11 mg/L로 나타났다. 겨울철에 비해 여름철에서의 오염물질의 유입농도가 높은 것으로 분석되었다. 이는 여름철 고온건조로 인한 노면 내 차량의 주행으로 인한 중금속, 폐타이어 등과 장마철 강우 시 유출된 토사로 인하여 유입수의 농도가 높은 것으로 분석되었다. 오염물질 부하량은 TSS와 COD 0.66으로 유의성이 높은 것으로 나왔으며, COD와 TSS, TP, TN 등 유의성이 높은 것으로 분석되었다. Arduino와 Raspberry PI를 활용하여 저비용 센서와 LTE 모뎀통신과 데이터 베이스 연결하여 개발된 프로그램을 통해서 무선으로 LID 시설에 대한 모니터링을 침투화분2와 식생체류지에 조성하였다. 전력공급이 어려운 식생체류지의 경우 태양열(Solar system) 시스템과 보조 전력 배터리를 조성하여 장마철이나 장기적인 악천후로 인한 전력을 생산하지 못할 경우 보조전력배터리에서 전력을 제공하여 지속적인 모니터링이 이루어지도록 설계하였다. 토양함수량, 토양온도와 Conductivity 등 3종류의 센서를 적용하였으며, 프로그램은 현재 2단계를 통한 2차수정을 통하여 프로그램을 구축하였다. 오차, 오작동, 계측값에 대한 검·보정 작업이 필요하다. 또한 대기자료의 구축을 통해 보다 토양과 LID 시설에 대한 영향분석이 필요한 것으로 사료된다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.43-43
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• 2021

로즈마리(Rosmarinus officinalis)는 지중해 지역이 원산이고 꿀풀과에 속하는 다년생 식물로 자생지에서는 식물의 크기가 2m까지 자라는 관목성 식물이다. 식용, 약용, 미용, 향료뿐 아니라 관상용으로도 널리 이용되고 있고 특히 향이 좋아 세계 로즈마리 추출물 시장은 연평균 4.8%씩 증가하여 2027년에는 10억 달러를 넘을 것으로 예측된다. 우리나라도 소비 트렌드 변화에 따른 이용성 확대로 신선허브의 수요가 증가하고 있으나 아직은 허브 식물원료의 대부분을 수입에 의존하고 있고, 로즈마리 역시 식물원료뿐 아니라 가공품까지 외국에서 수입하여 사용하는 실정이다. 2018년 로즈마리 수입량은 신선상태 978kg, 건조상태 23,404kg으로 높은 수입의존에 따른 가격 상승과 긴 유통기간에 의한 품질 저하 등의 문제가 발생하고 있다. 본 연구는 로즈마리 어린 순 재배 적정 삽수 길이를 설정하고 어린 순 생산 가능 기간을 구명하여 추후에 고품질 로즈마리 어린 순 집약생산을 위한 다단재배기술을 확립하고자 수행되었다. 삽수 길이는 5, 10, 15cm로 하였고, 삽목 시기는 4월 하순 ~ 8월 하순까지 30일 간격으로 5회 실시하였다. 적정 삽수 길이 설정 실험에서는 15cm 삽수 발근률이 85.6%로 가장 높았으며 신초 출현시기는 5월 26일, 어린 순 생산시기는 6월 23일로 가장 빨랐고 수확시까지 소요일수는 56일로 가장 짧았다. 기대수량 또한 728g/m²로 가장 높았다. 로즈마리 어린 순 생산 가능 기간 구명 실험에서는 4월 28일 삽목시 발근율이 85.6%로 가장 높았고 육묘기간은 28일 어린 순 생산까지 소요일수는 56일로 가장 짧았다. 삽목 시기별 어린 순 품질 및 생산량은 4월 28일 삽목시 품질이 좋았으며 기대수량 또한 728g/m²로 가장 높았다. 결과적으로 상품성 있는 어린순 생산에 적합한 삽수 길이는 15cm, 삽목 시기는 4월 하순 경에 했을 때, 로즈마리의 생육상태, 수확까지의 기간, 어린 순 생산량 등 종합적인 면에서 가장 우수한 값을 얻을 수 있었다.