• Title/Summary/Keyword: S-VAR

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The sparse vector autoregressive model for PM10 in Korea (희박 벡터자기상관회귀 모형을 이용한 한국의 미세먼지 분석)

  • Lee, Wonseok;Baek, Changryong
    • Journal of the Korean Data and Information Science Society
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    • v.25 no.4
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    • pp.807-817
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    • 2014
  • This paper considers multivariate time series modelling of PM10 data in Korea collected from 2008 to 2011. We consider both temporal and spatial dependencies of PM10 by applying the sparse vector autoregressive (sVAR) modelling proposed by Davis et al. (2013). It utilizes the partial spectral coherence to measure cross correlation between different regions, in turn provides the sparsity in the model while balancing the parsimony of model and the goodness of fit. It is also shown that sVAR performs better than usual vector autoregressive model (VAR) in forecasting.

Taxonomic study of Viola albida complex based on RAPD data (RAPD 자료에 근거한 태백제비꽃군의 분류학적 연구)

  • Koo, Ja Choon;Tak, Hyo Jin;Whang, Sung Soo
    • Korean Journal of Plant Taxonomy
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    • v.40 no.2
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    • pp.118-129
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    • 2010
  • A taxonomic study of Viola albida complex, containing the representative individuals of three taxa, V. albida var. albida, V. albida var. chaerophylloides, and V. albida var. takahashii, was done based on RAPD data. The amplified loci were 476 in total; obtained with 68 universal primers on seven OTUs. Nei's genetic dissimilarity appeared relatively low within individuals of V. albida var. albida and V. albida var. chaerophylloides (0.118-0.171 and 0.051 respectively), however, it was higher in individuals of V. albida var. takahashii (0.348). On the other hand, there is no specific trend in terms of genetic dissimilartiy among taxa, such as between individuals of V. albida var. albida and V. albida var. takahashii, between those of V. albida var. albida and V. albida var. chaerophylloides, and between those of V. albida var. albida and V. albida var. takahashii. The similarity of OTUs studied is high in clustering analysis, so that this result is compatible with the establishment of this complex. All OTUs are clustered within two groups. The individuals of V. albida var. takahashii, however, are clustered both to the group of V. albida var. albida and to the group of V. albida var. chaerophylloides, meaning that the genetic difference is high which would be commensurate with their morphological variations.

Studies on the Adriamycin produced from Streptomyces peucetius var. caesius Part 1. Isolation of Mutant (Streplomyces peucetius var. caesius에 의한 Adriamycin 생산(生産)에 관한 연구(硏究) 제1보(第一報). 변이주의 분리)

  • Won-Cheol, Shin
    • Journal of Industrial Technology
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    • v.2
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    • pp.21-25
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    • 1982
  • This study was to investigate the basic research about Adriamycin production from Streptomyces peucetius var. caesius. Streptococcus pyogenes(YUFE 2204) was sensitive against Adriamycin and its MIC value was $3.125{\mu}g/ml$. Several mutants were isolated by UV-light. Among 325 mutants, Streptomyces peucetius var. caesius YS-107 was showed highest productivity of Adriamycin.

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A New Variety of Geranium (Geraniaceae) from Korea: G koraiense Nakai var. hallasanense B.-J. Woo & S.-J. Park

  • Woo, Bok-Ju;Park, Seon-Joo
    • Animal cells and systems
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    • v.9 no.3
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    • pp.123-125
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    • 2005
  • A new variety, Geranium koraiense var. hallasanense B.-J. Woo & S.-J. Park, is described here from Jeju Island, Korea. The new variety is distributed only in Jeju Island, and readily distinguished from the other varieties of G. koraiense by its shape of radical leaf division, rounded or undulate petal apex, glabrous petal veins, densely pubescent stems, and stylar portion pubescent with trichomes in basal 1/4 portion. A key to the varieties of G. koraiense is provided.

The Numerical Analysis Model and Design Method in Var Catchment Nice, France (프랑스 니스 Var Catchment의 수치해석 및 설계방안)

  • Choi, Hyeong-Jin;Park, Hyun-Ki;Choi, Gye-Woon
    • Proceedings of the Korea Water Resources Association Conference
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    • 2012.05a
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    • pp.420-420
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    • 2012
  • 인류의 역사 이래로 하천관리에 있어서 치수는 주요 과제중의 하나였다. 대부분의 하천은 원활한 홍수 유통을 위해 직선화되었고 하폭은 확장되었다. 이로 인해 하천 생태계는 단순화되었고 홍수 피해 또한 줄지 않고 시가지 범람이라는 새로운 유형의 침수피해가 발생하였다. 최근까지도 홍수피해를 저감하고자 많은 노력을 기울이고 있고, 하천을 자연 친화형으로 설계, 복구하는 움직임이 활발하다. 하천을 설계함에 있어서 수치해석을 하고, 예측하는 것은 시간과 경제적인 장점으로 인해 많이 이용하고 있다. 본 연구에서는 대상지역을 프랑스 남부에 위치한 Var Catchemnt로 선정하였다. Var 유역은 $2,822km^2$의 면적, 총길이 125km, 최고 고도와 강 하구까지의 고도차가 3,000m의 급한 경사로 이루어진 유역이다. 이 지역은 매년 11월에서 1월 우기 때마다 빈번하게 홍수가 발생하는 지역으로 끊임없이 홍수에 따른 범람의 문제가 제기되고 있는 지역이다. 1994년 11월에 발생한 기록적인 폭우로 인해 최대유량 $3,500m^3/s$으로 관측되었고, 이 수치는 평균 유량의 50배에 이르는 유량이다. 이 홍수와 범람으로 인해 주변의 많은 시설이 피해를 입었으며, 도로가 유실되고, 인명피해도 상당했다. 본 연구에서는 수치해석을 위해 1차원 해석 프로그램인 DHI사의 MIKE11과 미공병단에서 개발한 Hec-Ras를 사용하였다. 홍수피해를 예방하기 위하여 가장 경제적이고 합리적인 방법은 제방의 높이를 변경하는 것으로 판단하여 수치해석을 실시한 후, 실제 데이터와의 비교를 통해 홍수를 예방하기 위한 제방의 높이를 결정하였다. Var 유역에 홍수를 예방하기 위해서는 강의 하구 쪽의 제방을 높일 필요가 있다고 판단되었다.

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Antioxidative Activity of Extracts from Sambucus williamsii var. coreana (딱총나무(Sambucus williamsii var. coreana) 추출물의 항산화효과)

  • Chae, Jung-Woo;Cho, Young-Je
    • Korean Journal of Plant Resources
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    • v.25 no.4
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    • pp.363-371
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    • 2012
  • Sambucus williamsii var. coreana have been used as a traditional medical food. This research was conducted to investigate the antioxidants of S. williamsii var. coreana leave and stem extracts. Total phenolic content of S. williamsii var. coreana leaves and stem water extracts were 6.6 and 2.0 mg/mL. The EDA by DPPH free radical scavenging test of S. williamsii var. coreana leaves extracts were 99.5 and 89.7% in water and ethanol extracts contained phenolic 200 ${\mu}g/mL$. The stem extracts were 92.2 and 94.3% in water and ethanol extracts contained phenolic 200 ${\mu}g/mL$. The ABTS radical decolorization activity of water and ethanol extracts from leaves were 79.8 and 99.1% at phenolic 200 ${\mu}g/mL$ and water and ethanol extracts from stem were 90.8 and 97.2% at phenolic 200 ${\mu}g/mL$. The antioxidant protection factor of water and ethanol extracts from leaves were 1.1 PF and 1.1 PF at phenolic 200 ${\mu}g/mL$ and water and ethanol extracts from stem were 1.4 PF and 1.0 PF at phenolic 200 ${\mu}g/mL$. The TBARs of water and ethanol extracts from leaves were 88.7 and 98.1% at phenolic 200 ${\mu}g/mL$ and water and ethanol extracts from stem were 93.6 and 90.6% at phenolic 200 ${\mu}g/mL$. The antioxidative activities of extracts from S. williamsii var. coreana leaves and stem were higher than BHT as positive control. These results suggests that S. williamsii var. coreana extracts have the greatest property as a natural antioxidative source.

Antigastritic and Antiulcerative Effects of Cirsium japonicum var. ussuriense Extract and Fractions (엉겅퀴(Cirsium japonicum var. ussuriense)추출물 및 분획물의 항위염 및 항위궤양 효과에 대한 연구)

  • Lee, Yu-Mi;Hwang, In-Young;Lee, Eun-Bang;Jeong, Choon-Sik
    • YAKHAK HOEJI
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    • v.55 no.2
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    • pp.160-167
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    • 2011
  • Cirsium japonicum var. ussuriense (CJ) is used as a folk medicine for diuretic, arthritis, dyspepsia, and bleeding in Korea. Until now, more than fifteen kinds of CJ were identified and among them, Cirsium japonicum var. nakaianum Nakai was selected as experimental material. Both that from The Medical Herb Garden of Seoul National University located at Gayang-dong, Koyang city and native that from a hillock near Dangjin, Chungnam were collected and analyzed to determine whether it is varied in efficacy on their habitats. Extracts and fractions of CJ had a strong effect of antibacterial activity on H. pylori and antioxidant effects. And the CJ from Garden and Dangjin were showed to be more efficient in acute gastritis through the HCl${\cdot}$ethanol-induced gastric lesion test and chronic gastritis through the indomethacin-induced gastric lesion test, respectively. This study proved that the effects of CJ are varied by their habitats. Also, these results suggest that the CJ has potentials for use as functional food and medicine.

Changes in Real Exchange Rate and Business Fluctuations: A Comparative Study of Korea and Japan (실질환율변동의 경기변동효과: 한국과 일본의 비교연구)

  • Kwak, Tae Woon
    • International Area Studies Review
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    • v.13 no.3
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    • pp.309-330
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    • 2009
  • This paper analyzes comparatively the effects of changes in real effective exchange rates on the business fluctuations of the cases of Korea and Japan employing structural vector auto-regression(S-VAR) model which uses quarterly data for the five variables of real effective exchange rates, GDP gap, real interest rates, oil prices, inflation rates for the period of 1980-2006. The paper employes impulse-response analysis and variance decompositions. The paper finds that real exchange rate depreciations are contractionay for the case of Korea while they are expansionary for the case of Japan. These results are consistent with the prevailing empirical results that real exchange rate depreciations are contractionary for developing countries while expansionary for advanced countries.

Biological activity of functional foods and anti-microbial activity of phenolics from Sambucus sieboldiana var. pendula leaves

  • Park, Hye-Jin;Lee, Eun-Ho;Jeong, Da-Eun;Han, Chae-Won;Kim, Byung-Oh;Kang, In-Kyu;Cho, Young-Je
    • Korean Journal of Food Science and Technology
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    • v.54 no.4
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    • pp.386-390
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    • 2022
  • This study aimed to investigate the biological and antibacterial activities of phenolics from Sambucus sieboldiana var. pendula leaf extract. The phenolic contents of the S. sieboldiana var. pendula extracted with water and ethanol was 11.60 and 12.39 mg/g, respectively. The inhibitory effects of the water and ethanol extracts on the angiotensin converting enzyme (ACE) were 71.94-92.08 and 48.42-78.33%, respectively, and on xanthine oxidase (XOase) were 42.11-100 and 35.61-100%, respectively, at a phenolic concentration of 50-200 ㎍/mL. All these effects were found to be concentration-dependent. Additionally, the leaf extracts exhibited excellent antibacterial activities against Streptococcus mutans, Staphylococcus aureus, and Propionibacterium acnes. Hence, S. sieboldiana var. pendula was confirmed to have excellent antihypertensive, antigout, and antimicrobial properties.