• Bulletin of the Korean Chemical Society
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• 제25권10호
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• pp.1513-1520
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• 2004

We investigate a series of synthesized ${\beta}$-methoxyacrylate analogues for their 3D QSAR & HQSAR against Magnaporthe grisea (Rice Blast Disease). We perform the three-dimensional Quantitative Structure-Activity Relationship (3D-QSAR) studies, using the comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) procedure. In addition, we carry out a two-dimensional Quantitative Structure-Activity Relationship (2D-QSAR) study, using the Hologram QSAR (HQSAR). We perform these studies, using 53 compounds as a training set and 10 compounds as a test set. The predictive QSAR models have conventional $r^2$ values of 0.955 at CoMFA, 0.917 at CoMSIA, and 0.910 at HQSAR respectively; similarly, we obtain cross-validated coefficient $q^2$ values of 0.822 at CoMFA, 0.763 at CoMSIA, and 0.816 at HQSAR, respectively. From these studies, the CoMFA model performs better than the CoMSIA model.

• Bulletin of the Korean Chemical Society
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• 제26권6호
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• pp.952-958
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• 2005

Angiotensin-converting enzyme (ACE) is known to be primarily responsible for hypertension. Threedimensional quantitative structure-activity relationship (3D-QSAR) models have been constructed using the comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) for a series of 28 ACE inhibitors. The availability of ACE crystal structure (1UZF) provided the plausible biological orientation of inhibitors to ACE active site (C-domain). Alignment for CoMFA obtained by docking ligands to 1UZF protein using FlexX program showed better statistical model as compared to superposition of corresponding atoms. The statistical parameters indicate reasonable models for both CoMFA ($q^2$ = 0.530, $r^2$ = 0.998) and CoMSIA ($q^2$ = 0.518, $r^2$ = 0.990). The 3D-QSAR analyses provide valuable information for the design of ACE inhibitors with potent activity towards C-domain of ACE. The group substitutions involving the phenyl ring and carbon chain at the propionyl and sulfonyl moieties of captopril are essential for better activity against ACE.

• Journal of Ecology and Environment
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• 제34권2호
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• pp.237-249
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• 2011

Land-use changes due to the socio-economic environment influence landscape patterns and processes, which affect habitats and biodiversity. This study considers the effects of such land-use changes, particularly on the traditional rural "Maeul" forested landscape, by analyzing landscape structure and vegetation changes. Three study areas were examined that have seen their populations decrease and age over the last few decades. Five types of plant life-forms (Raunkier life-forms) were distinguished to investigate ecosystem function. Principle component analysis was used to understand vegetation dynamics and community characteristics based on a vegetation similarity index. Ordination analysis transformed species-coverage data was introduced to clarify vegetation dynamics. Landscape indices, such as area metrics, edge metrics, and shape metrics, showed that spatial heterogeneity has increased over time in all areas. Pinus densiflora was the main land-use plant type in all study areas but decreased over time, whereas Quercus spp. increased. Over a decade, P. densiflora communities shifted to deciduous oak and plantation. These findings indicate that the impact of human activities on the Maeul landscape is twofold. While forestry activities caused heavy disturbances, the abandonment of traditional human activities has led to natural succession. Furthermore, it can be concluded that the type and intensity of these human impacts on landscape heterogeneity relate differently to vegetation succession. This reflects the cause and consequence of patch dynamics. We discuss an approach for sustainable landscape planning and management of the Maeul landscape based on traditional management.

• 전기학회논문지
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• 제66권8호
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• pp.1257-1264
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• 2017

In video content watching service, when a user requests video content, the content server has to transmit the entire video to the client for watching. This transmission delay increases as the size of video content increases. In order to solve the transmission delay problem, a prefetching technique can be used in which a video content to be watched by a user is predicted and transmitted to a client before the user requests it. In this paper, we propose a prefetching system considering multiple indices for video content. In the proposed method, video content to be prefetched is selected by comprehensively analyzing the order relation index indicating the order of viewing the videos of the users, the similarity index between the video contents, and the popularity index reflecting the viewing frequency of the video content. Experimental results show that the maximum accuracy is achieved when prefetching uses only the order relation index for movie contents.

• 천문학회보
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• 제41권1호
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• pp.46.2-46.2
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• 2016

We explore the similarity and difference of the quasi-periodic pulsations (QPPs) observed during the solar and stellar X-ray flares. For this, we identified 59 solar QPPs in the X-ray observed by the Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI) and 52 stellar QPPs from X-ray Multi Mirror Newton observatory (XMM-Newton). The Empirical Mode Decomposition (EMD) method and least-square-fit with the damped sine function are applied to obtain the periods and damping times of the QPPs. We found that (1) the periods and damping times of the stellar QPPs are 7.80 and 13.80 min, which are comparable with those of the solar QPPs 0.55 and 0.97 min. (2) The ratio of the damping times to the periods observed in the stellar QPPs are found to be statistically identical to the solar QPPs, (3) The damping times are well describe by the power law. The power indices of the solar and stellar QPPs are $0.891{\pm}0.172$ and $0.953{\pm}0.198$, which are consistent with the previous results. Thus, we conclude that the underlying mechanism responsible for the stellar QPPs are the natural oscillations of the flaring or adjacent coronal loops as in the Sun.

• Journal of Microbiology and Biotechnology
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• 제22권3호
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• pp.360-370
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• 2012

Current ecological knowledge of methanotrophic biofilms is incomplete, although they have been broadly studied in biotechnological processes. Four individual DNA samples were prepared from a methanotrophic biofilm, and a multiplex 16S rDNA pyrosequencing was performed. A complete library (before being de-multiplexed) contained 33,639 sequences (average length, 415 nt). Interestingly, methanotrophs were not dominant, only making up 23% of the community. Methylosinus, Methylomonas, and Methylosarcina were the dominant methanotrophs. Type II methanotrophs were more abundant than type I (56 vs. 44%), but less richer and diverse. Dominant non-methanotrophic genera included Hydrogenophaga, Flavobacterium, and Hyphomicrobium. The library was de-multiplexed into four libraries, with different sequencing efforts (3,915 - 20,133 sequences). Sorrenson abundance similarity results showed that the four libraries were almost identical (indices > 0.97), and phylogenetic comparisons using UniFrac test and P-test revealed the same results. It was demonstrated that the pyrosequencing was highly reproducible. These survey results can provide an insight into the management and/or manipulation of methanotrophic biofilms.

• Asian-Australasian Journal of Animal Sciences
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• 제20권12호
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• pp.1783-1790
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• 2007

The genetic diversity of domestic quail and two wild quail species, Japanese （Coturnix coturnix）and Common quail (Coturnix japonica), found in China was studied using microsatellite DNA markers. According to a comparison of the corresponding genetic indices in the three quail populations, such as Polymorphism Information Content (PIC), Mean Heterozygosity ($\bar{H}$) and Fixation Index, wild Common quail possessed rich genetic diversity with 4.67 alleles per site. Its values for PIC and $\bar{H}$ were the highest, 0.5732 and 0.6621, respectively. Domestic quail had the lowest values, 0.5467 and 0.5933, respectively. Wild Japanese quail had little difference in genetic diversity from domestic quail. In addition, from analyses of the fuzzy cluster based on standard genetic distance, the similarity relationship matrix coefficient between wild Japanese quail and domestic quail was 0.937, and that between wild Common quail and domestic quail was 0.783. All of these results showed that the wild Japanese quail were closer to the domestic quail for phylogenetic relationship than wild Common quail. These results at the molecular level provide useful data about quail's genetic background and further supported the hypothesis that the domestic quail originated from the wild Japanese quail.

• 약학회지
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• 제55권2호
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• pp.91-97
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• 2011

To search a new anti-depressant agents against para-chloroamphetamine-induced excitation, three dimensional quantitative-structure relationships (3D-QSAR) models between structure of 3a,4-dihydro-3H-[1]-benzopyronao[4,3]isoxazoles (1-30) and thieir inhibitory activity against para-chloroamphetamine-induced excitation were performed and discussed quantitatively using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) methods. From these basis on the findings, the optimized CoMSIA-2F model ($q^2$=0.793 and $r^2$=0.952) showed the best statistical results. And also, it is found that the para-chloroamphetamine inhibitory activity from the optimized CoMSIA-2F model was dependent on steric field (35.2%) and electrostatic field (64.8%) of tricyclic isoxazoles. Particularly, it is predicted that the inhibitory activity against para-chloroamphetamine-induced excitation will be able to increase by the designed compounds from the CoMSIA-2F model.

• 생태와환경
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• 제52권2호
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• pp.126-135
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• 2019

본 연구는 지난 50년간 (1969~2018년) 우리나라 연안 - 하구에서 수행된 어류먹이원 분석과 관련된 논문을 수집하여 현황을 파악하였다. 확인된 연구논문은 총 101편 이었으며, 이 중 국내 학회지에 발표된 논문은 81편, 보고서는 6편 그리고 국제 학회지에 발표된 논문은 14편이었다. 발표된 연구 논문을 10년 단위로 나누어 보면, 1990~1999년에 21편(19.4%; 2.1편${\pm}$3.0/년 [평균${\pm}$표준 편차]), 2000~2009년에 26편(24.1%; 2.6편${\pm}$2.3/년) 이후 크게 증가하여 2010~2018년에는 52편(48.1%; 5.8편${\pm}$2.3/년)의 논문이 출판되었다. 국내 연안-하구에서 어류먹이원 분석을 수행한 조사수역의 해역을 방위(남해, 남-동해, 동해, 서해)로 나누어보면, 남해에서 65편(69.1%)으로 가장 많은 연구가 이루어졌다. 그 뒤를 동해가 13편(13.8%), 서해와 남-동해에서 각각 8편씩(8.5%) 연구가 수행되었다. 조사 지역의 분포를 보면 광양만에서 18편(24.3%)으로 가장 많은 연구가 수행되었으며, 가덕도에서 8편(10.8%)으로 그 뒤를 이었다. 출간된 논문의 방법론적 특성을 보면, 먹이원 중요도나 생태적 지위의 범위를 나타내주는 지표를 계산하는 방법은 총 14가지가 사용되었으며, 이 중 가장 많이 사용된 지수는 IRI (Index of relative importance)와 Pi (Prey-specific abundance)였으며, E (electivity index)와 Bi (dietary breadth index)가 그 뒤를 이었다. 총 11가지 통계적 방법을 사용하였으며 이 중 correlation analysis와 Bray-Curtis similarity matrix를 가장 많이 적용하였다. 생태학적 연구 주제 변화를 살펴보면 초기 논문들은 계절적 또는 조사 지점별 차이에 초점을 맞추고 있었으나, 2000년도 이후부터는 국제 학회지에 출판되기 시작한 논문들은 종간 경쟁(competition), 동소성(sympatric), 생태직위중첩(niche overlap) 등과 같은 세부적인 생태학적 연구가 이루어졌다. 국내 학회지에 출판된 논문들의 경우 다소 정형화된 형태로 연구가 수행되고 있었으며 조사되지 않은 종에 대한 기초자료 제공 형태가 주류를 이루고 있었는데, 향후 국내 학회지에 발표되는 연구논문에서도 종간 경쟁, 먹이망 구조 파악 등과 같은 생태학적 주제를 반증할 수 있는 연구 방향이 지향되어야 할 것이다.

• 한국토양비료학회지
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• 제19권2호
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• pp.99-105
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• 1986

영남지역(嶺南地域) 역암(礫岩)에서 유래(由來)된 잔적토(殘積土)인 신정통(新亭統)의 분포지역간(分布地域間) 토양단면발달지수와 특성(特性)을 비교(比較)하여 본 결과(結果)는 다음과 같았다. 1. 조사토양(調査土壤)은 구릉지(丘陵地)의 역암잔적층을 모재(母材)로 한 식양질토양(埴壤質土壤)으로 토양배수(土壤排水)는 양호(良好)하며 대부분(大部分) 30~60% 경사지(傾斜地)에 분포(分布)하므로 현재(現在) 임지(林地)로 이용(利用)되는 토양(土壤)이었다. 2. 형태적(形態的) 특성(特性)은 표토(表土)는 황적색(黃赤色)(5YR) 내지(乃至) 황색(黃色)(10YR)의 양토(壤土)이며 심토(心土)는 (암(暗))적갈색(赤褐色)(5YR) 또는 적황색(赤黃色)(7.5YR)의 식양토(埴壤土)로 일부(一部) 토층에는 점토피막(粘土皮膜) 흔적(痕迹)이 있었으며 기층은 (암(暗))적갈색(赤褐色)(5YR) 또는 담갈색(淡褐色)(7.5YR)의 양토(壤土) 혹(或)은 사양토(砂壤土)이었다. 3. 조사토양(調査土壤)의 층위발달지수는 0.18~0.39로 점토피막(粘土皮膜)이 생성(生成)되어 있는 집적층만이 0.36 이상(以上)으로 높았으며 단면발달지수는 30.18~35.93index-cm로 서로 비슷하였다. 4. 층위발달지수는 구조(構造), 토성(土性), 결지성(結持性) 등(等)의 평균화(平均化) 값과 정상관(正相關)이 있었지만 단면발달지수와 결지성(結持性)의 평균화(平均化) 값과는 오히려 상반(相反)되는 경향(傾向)이었다. 5. 용탈층에서 집적층으로 용탈집적(溶脫集積)된 점토량(粘土量)은 모재(母材) 100gr당(當) 1.1~1.6gr으로서 용탈률(溶脫率)은 4.4~5.9%로 낮았으며 단면발달지수와 같이 그 차(差)가 크지 않았다. 6. 조사토양(調査土壤)이 함유(含有)한 석력(石礫)의 원마도(圓磨度) 및 구형도(球型度)는 각각(各各) 평균(平均) 0.741, 0.715로서 거의 구형(球型)에 가까운 "완원력(完圓礫)"에 해당(該當)되어 모암(母岩)의 퇴적환경(堆積環境)이 유사(類似)하였던 것으로 볼 수 있었다.