• 설비공학논문집
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• 제16권10호
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• pp.942-951
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• 2004

This paper presents the results of a theoretical study of the effect of radiation during free convective laminar film boiling for methanol/water binary mixtures on an isothermal vertical wall at atmospheric pressure. With the well-known boundary layer theory as a basis, a theoretical model has been formulated into consideration for mass diffusion at liquid phase. The equations are numerically solved by a similarity method to investigate the effects of radiation emissivity on the surface with various parameters such as wall superheat and composition of more volatile component at liquid phase far from the wall. From the results, the distributions of the physical quantifies are investigated in both phases. New correlations are proposed to predict the heat transfer coefficient of binary mixtures. It is shown that the proposed correlations are in good agreement with numerical results and with Bromley's correlation within maximum $11\%$ errors. It is also found that as the wall superheat is increased, radiation effect becomes more important.

• Investigative Magnetic Resonance Imaging
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• 제25권3호
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• pp.156-163
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• 2021

Recently, neuromelanin and nigrosome imaging techniques have been developed to evaluate the substantia nigra in Parkinson's disease. Previous studies have shown potential benefits of quantitative analysis of neuromelanin and nigrosome images in the substantia nigra, although visual assessments have been performed to evaluate structures in most studies. In this study, we investigate the potential of using deep learning based automatic region segmentation techniques for quantitative analysis of the substantia nigra. The deep convolutional neural network was trained to automatically segment substantia nigra regions on 3D nigrosome and neuromelanin sensitive MR images obtained from 30 subjects. With a 5-fold cross-validation, the mean calculated dice similarity coefficient between manual and deep learning was 0.70 ± 0.11. Although calculated dice similarity coefficients were relatively low due to empirically drawn margins, selected slices were overlapped for more than two slices of all subjects. Our results demonstrate that deep convolutional neural network-based method could provide reliable localization of substantia nigra regions on neuromelanin and nigrosome sensitive MR images.

• 한국전자파학회논문지
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• 제15권11호
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• pp.1082-1089
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• 2004

본 논문에서는 개방 루프 공진기로 구현된 타원응답 필터의 소형화 및 결합행렬의 유사변환을 통한 설계의 유연성에 관해 연구하였다. 더불어 제안한 방법에 의하여 보다 큰 비대역폭을 갖는 필터를 제시하였다. 제안한 방법의 유효성을 확인하기 위해 개방 루프 공진기를 이용하여 중심 주파수(f$_{c}$) 2.0 GHz에서 0.04의 비대역폭(FBW)을 가지는 4차 타원응답 대역통과 필터를 설계하였다. 개방 루프 공진기의 혼합결합이 일어나는 부분의 선폭을 좁게 함으로써 구현된 두 개의 필터는 일정한 선폭을 가지는 공진기로 구현된 필터에 비해 각각 13%와 25%의 크기 감소 효과를 나타내었다. 또한, 요구되는 결합량을 만족시키기 위한 공진기 사이의 간격이 실현 불가능할 경우 결합행렬의 유사변환을 통하여 기존 구조와 동일한 특성을 나타내는 두 가지 다른 구조를 제시함으로써 필터 설계의 유연성을 보여주었으며 이로 인해 보다 큰 비대역폭(FBW=0.08)을 갖는 필터 설계가 가능함을 나타내었다.

• Journal of Animal Science and Technology
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• 제57권12호
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• pp.44.1-44.9
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• 2015

Background: Heat shock proteins play an important role in protection from stress stimuli and metabolic insults in almost all organisms. Methods: In this study, computational tools were used to deeply analyse the physicochemical characteristics and, using homology modelling, reliably predict the tertiary structure of the blunt snout bream (Ma-) Hsp70 and Hsc70 proteins. Derived three-dimensional models were then used to predict the function of the proteins. Results: Previously published predictions regarding the protein length, molecular weight, theoretical isoelectric point and total number of positive and negative residues were corroborated. Among the new findings are: the extinction coefficient (33725/33350 and 35090/34840 - Ma-Hsp70/ Ma-Hsc70, respectively), instability index (33.68/35.56 - both stable), aliphatic index (83.44/80.23 - both very stable), half-life estimates (both relatively stable), grand average of hydropathicity (-0.431/-0.473 - both hydrophilic) and amino acid composition (alanine-lysine-glycine/glycine-lysine-aspartic acid were the most abundant, no disulphide bonds, the N-terminal of both proteins was methionine). Homology modelling was performed by SWISS-MODEL program and the proposed model was evaluated as highly reliable based on PROCHECK's Ramachandran plot, ERRAT, PROVE, Verify 3D, ProQ and ProSA analyses. Conclusions: The research revealed a high structural similarity to Hsp70 and Hsc70 proteins from several taxonomically distant animal species, corroborating a remarkably high level of evolutionary conservation among the members of this protein family. Functional annotation based on structural similarity provides a reliable additional indirect evidence for a high level of functional conservation of these two genes/proteins in blunt snout bream, but it is not sensitive enough to functionally distinguish the two isoforms.

• Journal of Microbiology and Biotechnology
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• 제20권1호
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• pp.169-178
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• 2010

The microbial community structure in Thailand soils contaminated with low and high levels of arsenic was determined by denaturing gradient gel electrophoresis. Band pattern analysis indicated that the bacterial community was not significantly different in the two soils. Phylogenetic analysis obtained by excising and sequencing six bands indicated that the soils were dominated by Arthrobacter koreensis and $\beta$-Proteobacteria. Two hundred and sixty-two bacterial isolates were obtained from arsenic-contaminated soils. The majority of the As-resistant isolates were Gramnegative bacteria. MIC studies indicated that all of the tested bacteria had greater resistance to arsenate than arsenite. Some strains were capable of growing in medium containing up to 1,500 mg/l arsenite and arsenate. Correlations analysis of resistance patterns of arsenite resistance indicated that the isolated bacteria could be categorized into 13 groups, with a maximum similarity value of 100%. All strains were also evaluated for resistance to eight antibiotics. The antibiotic resistance patterns divided the strains into 100 unique groups, indicating that the strains were very diverse. Isolates from each antibiotic resistance group were characterized in more detail by using the repetitive extragenic palindromic-PCR (rep-PCR) DNA fingerprinting technique with ERIC primers. The PCR products were analyzed by agarose gel electrophoresis. The genetic relatedness of 100 bacterial fingerprints, determined by using the Pearson product-moment similarity coefficient, showed that the isolates could be divided into four clusters, with similarity values ranging from 5-99%. Although many isolates were genetically diverse, others were clonal in nature. Additionally, the arsenic-resistant isolates were examined for the presence of arsenic resistance (ars) genes by using PCR, and 30% of the isolates were found to carry an arsenate reductase encoded by the arsC gene.

• Ecology and Resilient Infrastructure
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• 제5권3호
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• pp.145-155
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• 2018

In a monsoonal climate, the soil seed bank can play an important role in plant regeneration after the severe annual floods that disturb above-ground vegetation within the riparian zone. To investigate the relationship between the soil seed bank and vegetation, we measured the species composition of the soil seed bank and the extant above-ground vegetation in six major plant communities (Artemisia selengensis, Miscanthus sacchariflorus, Persicaria nodosa, Phalaris arundinacea, Phragmites japonica, and Rorippa palustris) in the Cheongmicheon Stream, Korea. A total of 21 species germinated from the floodplain soil seed banks. The most diverse seed bank (21 species) was found in the A. selengensis community, wheres the lowest number of species was found in the R. palustris community (2 species). Most soil seed banks were composed of annuals (90%), exceptions being Rumex crispus and Artemisia princeps, which are perennial ruderals. The similarity of species composition between the soil seed bank and above-ground vegetation was low with Sorensen's similarity indices averaging 29% (range 12 - 42%). Crucially, existing dominant perennials of the extant vegetation including A. selengensis, M. sacchariflorus, P. japonica and P. arundinacea were absent from the soil seed bank. In conclusion, the soil seed banks of the floodplains of the Cheongmicheon Stream were mainly composed of viable seeds of ruderal plants, which could germinate rapidly after severe flood disturbance. The soil seed bank may, therefore, be useful for the restoration of the early succession stages of riparian vegetation after flood disturbances.

• 한국잠사곤충학회지
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• 제44권2호
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• pp.59-63
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• 2002

본 연구에서는 형태적인 특성에 의해 분류가 이루어져, 객관성이 부족한 뽕나무를 대상으로 분자생물학적인 기법을 활용하여 유연관계를 분석하여 뽕나무 품종분류의 기초자료를 얻기 위하여 본 실험을 수행하였다. 30개의 primer를 이용하여 41개의 뽕나무품종에 대하여 RAPD를 수행한 결과 201개의 band를 얻었으며, 이중 151개의 polymorphic band를 집괴분석하여 dendrogrom을 작성하였다. 이 계통수에서 유사도 0.747을 기준으로 41개의 공시 계통을 19개 품종과 16품종이 각각 속해있는 2개의 대분류군과 2품종이 속하는 1개의 군 그리고 1품종씩 속하는 4개의 군으로 모두 7개의 분류군으로 나눌 수 있었다. 분류군별 관계를 보면 I군, II군, III군에 속하는 품종들은 유전적 상동성이 비교적 높았으나, IV-Ⅶ군에 속하는 품종들은 다른 품종군들과 유연관계가 비교적 낮았으며, 특히 단독으로 하나의 군을 형성(Ⅶ군)하는 모후상은 다른 품종군들과의 유연관계가 매우 낮았다.

• 원예과학기술지
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• 제19권2호
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• pp.159-162
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• 2001

한국에 자생하는 22지역의 바위솔속 식물들의 유전적 근연관계를 구명하기 위하여 RAPD분석을 실시하였다. 18종의 바위솔속 식물은 3개의 군(A, B, C 군)으로 집괴되었으며, 나머지 4종은 어떤 분류군에도 속하지 않았다. A군인 연화바위솔(No.18-No.22)은 유사도가 66.3-73.9%로 낮게 나타났으며, B군인 둥근바위솔(No.12-No.17)도 유사도 지수가 69.7-83.7%로 비교적 낮게 나타났다. C군인 바위솔(No.3-No.9)은 안면도 수집종(No.9)을 제외한 유사도 지수가 84.2-92.3%로 높아, 지역종 간에 변이가 적은 비교적 유전적으로 안정된 종으로 생각되었다.

• 화훼연구
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• 제18권3호
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• pp.201-206
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• 2010

심비디움속 유전자원 48품종에 대하여 RAPD와 URP를 이용하여 유전적 유연관계를 분석하였다. RAPD분석에는 10mer에 해당하는 random primer (Operon사) 80개를, URP는 20 mer에 해당하는 12종의 상용 primer를 이용하였다. 48 품종의 심비디움에는 34종의 동양 심비디움, 7종의 동서양란 교잡종, 7종의 서양 심비디움이 포함되어 있다. 선별된 41개의 random primer와 6개의 URP primer로부터 각각 407, 56개의 다형성 밴드를 획득하여 총 463개의 마커를 이용하였다. 이들 마커의 크기 범위는 0.4 kb 에서 1.5 kb 에 해당하였다. 유전적 유사도를 바탕으로 UPGMA clustering 프로그램을 이용하여 dendrogram을 작성하였는데 유전자원 48품종은 유사도 0.638 수준에서 총 4그룹으로 구분되었다.

• 한국자원식물학회지
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• 제13권2호
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• pp.104-110
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• 2000

가시오갈피 및 오갈피의 수집종 간의 유연관계를 구명하기 위하여 RAPD 분석을 한 결과 10개의 primer를 선발하였으며 G+C의 수가 모두 60%이상이었다. 10개의 primer를 사용하여 얻을 수 있는 총 밴드 수는 106개 였으며 이중 monomorphic한 밴드는 17.9%에 해당하는 19개였으며 나머지 87개는 polymorphic한 것으로 나타났다. 10개의 primer를 사용하여 얻은 106개의 밴드를 각각 하나의 형질(character)로 보아 이를 유연관계를 분석한 결과 영월 수집종과 일본종 및 지리산 오갈피와 서울오갈피를 포함하는 군(Group I )과 국내종과 러시아종, 중국종을 포함하는 군(Group II)으로 나뉘어졌으며 genetic distance값의 평균은 0.61이었다. Group I으로 분류된 북해도 가시오갈피는 국내의 각 수집지역의 가시오갈피나 러시아 가시오갈피와 원연의 관계인 것으로 나타났으며 2군에 포함된 수집 지역종 간의 원연 관계 중 춘천 수집종은 국내의 다른 지역인 잠곡이나 태기산 오대산 등과 비교하여 러시아 산이나 중국산에 대하여 더 근연의 관계를 나타내었다.