• 한국미생물·생명공학회지
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• 제46권4호
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• pp.390-394
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• 2018

Endoxylanase와 endoglucanase 유전자가 ADH1 프로모터 하류에 따로따로 삽입된 pAGX3 플라스미드를 함유한 Saccharomyces cerevisiae에서 endoxylanase와 endoglucanase 유전자는 성공적으로 발현되었으며, YPD 배지에서의 회분배양 결과, endoxylanase는 7.91 units/ml, endoglucanase는 0.43 units/ml에 달하는 총활성을 보였다. Yeast extract와 포도당을 간헐적으로 공급하는 유가배양에서 endoxylanase와 endoglucanase의 총활성은 24.9 units/ml과 0.84 units/ml을 각각 보였으며, 이는 회분배양에서 발현된 각각 활성의 3.1배와 2배에 해당되었다. 또한, 대부분의 endoxylanase와 endoglucanase 활성은 세포밖 배지에서 측정되어, 향후 이 재조합 효모는 섬유소(cellulose)와 xylan 혼합물의 동시당화 바이오공정 개발에 활용될 가능성이 높다 하겠다.

• 한국유기농업학회지
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• 제26권4호
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• pp.649-660
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• 2018

Colletotrichum acutatum에 의해 발생하는 고추탄저병을 방제하기 위해 토양 근권으로부터 분리한 미생물 중 길항효과가 있는 미생물을 선발하여 주요 작물병원균에 대한 항균활성 효과와 포장에서의 방제효과를 검정하였다. 기내 대치배양법을 이용한 길항력을 검정하였을 때, CAB13001 균주는 고추 탄저병을 일으키는 Colletotrichum acutatum을 포함한 식물 병원균 Sclerotinia cepivorum, Sclerotinia sclerotium, Botrytis cinerea에 대한 뛰어난 항균활성 효과를 보였다. 또한 풋고추를 이용한 생체 검정에서 선발균주는 고추 탄저병의 병반진전 억제효과가 우수하였으며, 포장에서의 방제가 역시 무처리 대비 82.4%로 매우 우수하였다. 이러한 결과로 볼 때 CAB13001 균주는 공기 전염을 하는 고추 탄저병의 생물적 방제제로 매우 유용할 것으로 판단된다. 한편, 본 연구에 사용된 길항미생물 CAB13001 균주는 16s rRNA gene의 계통학적 위치를 분석한 결과 Burkholderia lata로 동정하였다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2015년도 학술발표회
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• pp.222-222
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• 2015

Vietnam is one of the most vulnarable countries affected by climate change and sea level rise. One of the consequences of climate change and sea level rise is the increase of salinity intrusion into the rivers which is challenging to irrigation systems in coastal areas. This indicates the necessary to study the ability of taking water through sluice gates of irrigation systems in coastal zones, especially in the dry season with the effects of climate change and sea level rise in the future. In this paper, Nam Thai Binh irrigation system is selected as a case study. The irrigation system is one of 22 biggest irrigation systems of the Red River delta in Vietnam located in coastal region. The computed duration is selected in dry season to irrigate for Winter-Spring crops. The irrigation water for the study area is taken from different sluice gates along the Red River and the Tra Ly River. In this paper, MIKE-11 model was applied to assess the ability of taking water for irrigation of the study area in current situation and in the context of climate change and sea level rise senario in 2050 (under the medium emissions scenario (B2) published by the Ministry of Natural Resources and Environment of Vietnam published in 2012) with different condition of water availability. The operation of the gates depends on the water levels and sanility conditions. The sanility and water level at different water intake gates of Nam Thai Binh irrigation system were simulated with different senarios with and without climate change and sea level rise. The result shows that, under climate change and sea water level rise, some gates can take more water but some can not take water because of salinity excess and the total water taking from the different gates along the rivers decrease while the water demand is increase. The study indicates the necessary to study quantitatively some recommended solutions in the study area particularly and in coastal region generally in Vietnam to ensure water demand for irrigation and other purposes in the context of climate change and sea level rise in the future.

• 국제강구조저널
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• 제18권4호
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• pp.1252-1264
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• 2018

Long span bridges such as steel cable stayed and suspension bridges are usually more flexible than short to medium span bridges and expected to have large deformations. Deflections due to live load for long span bridges are important since it controls the overall heights of the bridge for securing the clearance under the bridge and serviceability for securing the comfort of passengers or pedestrians. In case of sea-crossing bridges, the clearance of bridges is determined considering the height of the ship master from the surface of the water, the trim of the ship, the psychological free space, the tide height, and live load deflection. In the design of bridges, live load deflection is limited to a certain value to minimize the vibrations. However, there are not much studies that consider the live load deflection and its effects for long span bridges. The purpose of this study is to investigate the suitability of live load deflection limit and its actual effects on serviceability of bridges for steel cable-stayed and suspension bridges. Analytical study is performed to calculate the natural frequencies and deflections by design live load. Results are compared with various design limits and related studies by Barker et al. (2011) and Saadeghvaziri et al. (2012). Two long span bridges are selected for the case study, Yi Sun-Sin grand bridge (suspension bridge, main span length = 1545 m) and Young-Hung grand bridge (cable stayed bridge, main span length = 240 m). Long-term measured deflection data by GNSS system are collected from Yi Sun-Sin grand bridge and compared with the theoretical values. Probability of exceedance against various deflection limits are calculated from probability distribution of 10-min maximum deflection. The results of the study on the limitation of live load deflection are expected to be useful reference for the design, the proper planning and deflection review of the long span bridges around the world.

• 한국지형학회지
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• 제25권2호
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• pp.63-80
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• 2018

The purpose of this study was to investigate the physicochemical characteristics and formation age of sand dunes in the Okjukdong and Dajindong, Daecheong Island. As a result, most of the sand deposited in Okjukdong were composed of medium sized sand with moderately well sorted. The $SiO_2$ and $Al_2O_3$ accounted for a very high proportion of these deposits. There were some differences in characteristics between the sands in the dune and beach, whereas similar characteristics were observed among the materials (OJ-B, OJ-C and OJ-D) in the dune. In case of Dajindong, heterogeneous geochemical characteristics were found in the lower point. It was estimated that this was due to the influence of Daejin-dong black beach. Age dating results showed that uncovered dunes in Okjukdong were deposited $0.44{\pm}0.02$ ~ $0.50{\pm}0.02ka$, and sand depositsin Dajindong were formed $0.16{\pm}0.01$ ~ $0.18{\pm}0.01ka$. In both Okjukdong and Dajindong, sand deposits estimated to be formed 70 years ago, therefore it can be estimated that sand movement was active throughout the area from about hundred years ago. In this study area, the growth of sand dunes has been active in recent several decades or hundred years. It seems that there were different regions where deposits predominated over time. The source of dune sand was also different from time to time. Since the windbreak forest was established, the natural growth of sand dunes was limited, and sand nourishment was carried out by period. Therefore, in order to protect and continuously utilize coastalsand dunesin Daecheong Island, it is necessary to prepare conservation plan.

• Journal of Microbiology and Biotechnology
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• 제32권10호
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• pp.1315-1324
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• 2022

Fermentation is an effective process for providing various beneficial effects in functional beverages. Lactic acid bacteria and yeast fermentation-based biotransformation contribute to enhancement of nutritional value and digestibility, including lactose intolerance reduction and control of infections. In this study, the probiotic fermented fruit juice (PFJ) was produced by Lactobacillus plantarum TISTR 1465, Lactobacillus salivarius TISTR 1112, and Saccharomyces boulardii CNCM I-745 while mixed fruit juice (MFJ) was used as the basic medium for microorganism growth. The potential function, the anti-salmonella activity of PFJ, was found to be effective at 250 mg/ml of MIC and 500 mg/ml of MBC. Biofilm inhibition was performed using the PFJ samples and showed at least 70% reduction in cell attachment at the MIC concentration of Salmonella Typhi DMST 22842. The antioxidant activities of PFJ were determined and the results revealed that FSB.25 exhibited 78.40 ± 0.51 mM TE/ml by FRAP assay, while FPSB.25 exhibited 3.44 ± 0.10 mM TE/ml by DPPH assay. The volatile compounds of PFJ were characterized by GC-MS, which identified alcohol, aldehyde, acid, ester, ketone, phenol, and terpene. The most abundant organic acid and alcohol detected in PFJ were acetic acid and 2-phenylethanol, and the most represented terpene was β-damascenone. The sensory attributes showed scores higher than 7 on a 9-point hedonic scale for the FPB.25, illustrating that it was well accepted by panelists. Taken together, our results showed that PFJ could meet current consumer demand regarding natural and functional, fruit-based fermented beverages.

• 한국융합학회논문지
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• 제13권5호
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• pp.97-102
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• 2022

본 연구에서는 누에 추출물과 여주 추출물이 S. mutans와 F. nucleatum에 미치는 항균효과를 알아보고자 하였다. BHI 액체배지에 S. mutans 또는 F. nucleatum과 0%, 2%, 4%, 8% 농도의 누에가루 또는 여주가루 추출물을 첨가하여 배양한 뒤 광학밀도 600nm에서 시료를 측정하였다, 그 결과 S. mutans의 흡광도는 누에 추출물에서는 8%에서만 유의적으로 흡광도의 수치가 감소하였고 여주 추출물에서는 모든 농도에서 유의적으로 흡광도의 수치가 감소하였다. F. nucleatum의 흡광도는 누에 추출물과 여주 추출물에 모두 농도 의존적으로 유의적으로 감소하였다. 이는 누에 추출물과 여주 추출물이 구강질병의 예방 및 치료들 위한 소재로 사용 할 수 있는 가능성을 시사한다.

• Journal of Forest and Environmental Science
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• 제39권1호
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• pp.55-64
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• 2023

Properties of a lesser-used wood species were investigated to determine its potential for structural utilization. Trees of Delonix regia were felled and sampled at the base, middle and top and then sectioned to inner wood, middle wood, and outer wood for variation across the axial and radial directions. Hence, selected physical and mechanical properties as well as natural durability of D. regia along the radial and axial directions were examined. Obtained data were analyzed using analysis of variance (ANOVA) at α_0.05. There was no significant difference in the Moisture content (MC) of the wood but specific gravity (SG) decreased from base to top ranging from 0.35-0.44. Water absorption, volumetric swelling, and volumetric shrinkage range from 46.18-51.86%, 2.57-4.02%, and 2.26-3.96% respectively along the axial plane. The weight loss for graveyard exposure and accelerated laboratory decay test ranged from 25.14-48.00% and 32.02-44.45% respectively. Modulus of Rupture and Modulus of Elasticity values range from 29.42-72.68 Nmm² and 3,834.54-8,830.37 Nmm² respectively. The SG values has confirmed the species as a medium density wood and values of other properties tested showed that the wood is dimensional stable and moderately resistance to fungi and termite. Hence, it could be used for light construction purposes such as furniture and other interior woodwork.

• 스마트미디어저널
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• 제11권2호
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• pp.18-24
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• 2022

많은 소셜 서비스 상에서 악성 댓글로 인한 문제가 발생되고 있으며, 특히 매체로서의 성격이 강한 유튜브는 모바일기기를 이용한 쉬운 접근성으로 인해 악성 댓글로 인한 폐해가 더욱 커지고 있는 실정이다. 본 논문에서는 LSTM 기반의 자연어 처리를 통해 유튜브 콘텐츠에 대한 악성 댓글을 판별하고 악성 댓글의 비율, 악플러들의 닉네임, 그리고 빈도를 시각적으로 표현해 주기 위한 유튜브 악성 댓글 탐지 시스템을 설계하고 구현하였으며, 성능을 평가하였다. 약 5만 개의 댓글 데이터셋을 통해 악성 댓글 여부를 판별하였을 때, 약 92%의 정확도로 악성 댓글을 검출해 낼 수 있었으며, 이를 활용하여 악성 댓글의 통계가 자동으로 생성되도록 함으로써 많은 유튜버들이 겪는 악성 댓글로 인한 사회적 문제를 해결할 수 있을 것으로 기대한다.

• 한국환경농학회지
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• 제41권1호
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• pp.50-54
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• 2022

BACKGROUND: Phyllospadix japonica Makino is a perennial plant belonging to the family Zosteraceae. This species is native to the eastern coast of the Korean Peninsula, and it is found attached to rocks on the seashore. As with all seagrass species, P. japonica is also known to play a major role in protecting the marine environment, and studies on its physiological activities suggestive of its antioxidant, antibacterial and anti-inflammatory potentials have been reported. In this study, purification and structural analysis were performed to identify the polyphenol substances derived from P. japonica. METHODS AND RESULTS: An polyphenol substance MP-1 was purified from the 70% aqueous methanol extract of P. japonica using Diaion® HP-20 column chromatography, ODS column chromatography, and medium-pressure liquid chromatography (MPLC). The purified MP-1 was identified as rosmarinic acid having a molecular weight of 360 and a molecular formula of C18H16O8 through electrospray ionization (ESI)-mass and nuclear magnetic resonance (NMR) spectroscopic analysis. CONCLUSION(S): This study highlights the processes used for the identification of the polyphenol substance derived from P. japonica. Rosmarinic acid, the polyphenol derived from P. japonica identified by this study, is a kind of bioactive substance mainly present in plants. These findings provide an important starting point and are valuable for future studies on bioactive substances in seagrass.