• Title/Summary/Keyword: Niche

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Impact of Environmental Factors on in vitro Interactions and Niche Overlap between Aspergillus ochraceus and other Storage Fungi (Aspergillus ochraceus와 다른 저장균간의 in vitro 상호작용 및 Niche Overlap에 미치는 환경요인의 영향)

  • Lee, Hyang-Burm;Magan, Naresh;Yu, Seung-Hun
    • The Korean Journal of Mycology
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    • v.27 no.4 s.91
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    • pp.283-288
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    • 1999
  • The effect of water activity ($a_w,\;0.9{\sim}0.995$) and temperature ($18{\sim}30^{\circ}$C) on in vitro growth and interactions between ochratoxin-producing Aspergillus ochraceus and six other fungi (Alternaria alternata, Aspergillus candidus, A. flavus, A. niger, Eurotium amstelodami, E. rubrum) isolated from maize grain were investigated. A. ochraceus and each six other species were paired and their interactions given a numerical score to obtain an index of dominance ($I_D$) for each species. Generally A. ochraceus was very competitive and dominant against other fungi. It was, however, dominanted by Alternaria alternata and A. niger at high $a_w\;(0.995\;a_w)$, and mutually antagonistic when paired with E. amstelodami and E. rubrum at low $a_w\;(0.9\;a_w)$. The growth rates of each species were also calculated under the same range of environmental conditions. They were markedly influenced by aw and temperature. At high temperature ($30^{\circ}C$), A. ochraceus grew most rapidly under slightly drier conditions ($0.95\;a_w$), while A. alternata, A. flavus and A. niger did at high water availability level ($0.995\;a_w$). At $18^{\circ}C\;and\;25^{\circ}C$, and high $a_w$ level ($0.995\;a_w$), A. alternata grew fastest, while A. candidus, E. amstelodami and E. rubrum grew very slowly. Using Biolog plates the effect of $a_w$ and temperature on utilization patterns of carbon sources in maize was evaluated. The niche overlap index (NOI) relative to A. ochraceus was determined and compared with that of each interacting species. Under high water available condition ($0.995\;a_w$). the NOI of A. ochraceus was often >0.9, indicative of the coexistence with other interacting species. However, against E. amstelodami and E. rubrum at $18^{\circ}C$, the species had NOI <0.8, indicative of occupation of different niches. At low $a_w\;(0.95\;a_w)$, NOI for A. ochraceus was <0.8 when paired with A. alternata and A. niger also suggested the occupation of different niches.

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Study on the Renewable Energy Technology Market; based on Photovoltaics, Fuel cell, and Wind (신재생 에너지기술 시장 평가 (태평광, 연료전지, 풍력을 중심으로))

  • Park Soo-uk;Lee Deokki;Choi Sangjin
    • 한국신재생에너지학회:학술대회논문집
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    • 2005.06a
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    • pp.577-584
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    • 2005
  • There are many activities involved in promoting renewable energy technologies. These include governments, the renewable energy manufacturing and service industries, energy supply companies, investors, researchers, non-government organizations and customers. For a sustainable renewable energy market, finding a promising industry is essential. The industry has made significant progress in recent years, considering the fact that today's renewable energy market is relatively small. This paper analyses the technology market of renewable energy, focusing on photovoltaic system, fuel cell, wind system. It appears that there has been remarkable progress in renewable energy systems. Besides, developed countries are effectively increasing the share of niche market and promoting renewable energy worldwide.

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The Vegetation of Seogno Island (序毛島의 植生)

  • Kil, Bong-Seop;Jeong-Un Kim
    • The Korean Journal of Ecology
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    • v.7 no.4
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    • pp.208-232
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    • 1984
  • A survey was conducted on the vegetation of Seogmo island, which is small island (ca. 41 okm2) located about 1km west of Kanghwa island in the central Korea, from Aug. 1983 to May 1984. Based on the field data, actual vegetation map and potential natural vegetation map were made. The island is covered with broad-leaved trees dominated with Quercus variabilis. The dominance diversity curves obtaiend in different associations are grouped in two types, lognormal distribution forms at the undisturbed vegetation and geometric series at the disturbed or rocky sites. It seems that the curves show to us the nature of their ecocline by the hypothesis of some investigators, i.e. Random niche boundary hypothesis, niche preemption hypothesis, lognormal distribution and logarithmic series. Total numbers of vascular plant species of the island were recorded 108 families, 348 genera, 475 species, 73 variaties and 7 forma. And Pte.-Q Index, 0.93, and Fisher's Index, 589.8, were higher than those in neighboring islands.

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Niche Market Strategies of Local Players in the European Steel Industry (유럽 철강산업 Local Player의 틈새시장 공격전략)

  • 정경희
    • Korean Management Science Review
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    • v.20 no.2
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    • pp.45-59
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    • 2003
  • This study considers the local players in the European steel industry, whose the amounts of crude production are more or less 5 million tons per annum. They do not belong to the Pan-EU mega-group of steel mills with more than 15 million tons of crude production yearly. However, these mid-sized steel mills in European countries have been originated from the strong foundation of steel, scientifically and technically, as well as the centennial history. They concentrate on the niche market adjacent to the local area, which takes advantage of the geographical location. The companies considered here are VoestAlpine in Austria, Salzgitter in Germany, Rautaruukki in finland, and SSAB in Sweden. Their corporate strategies are compared on the basis of product mix and sales structure. And, the deep analysis for each company is performed, such as business strategies with the sales volumes, market strategies. competitiveness improvement planning. and R&D policies with the technology management. These analysis results can be benchmarked as the cases of best practices for domestic steel mills, especially mid & small sized companies, that develop business and market strategies for the sustainable growth and profitability.

Predicting the Invasion Pathway of Balanus perforatus in Korean Seawaters

  • Choi, Keun-Hyung;Choi, Hyun-Woo;Kim, Il-Hoi;Hong, Jae-Sang
    • Ocean and Polar Research
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    • v.35 no.1
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    • pp.63-68
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    • 2013
  • The European Common Barnacle Balanus perforatus Brugiere (Crustacea, Cirripedia) has been introduced into the east coast of Korea, presumably via the ballast water of ships. The species has since been spreading along both the northern and southern coast to the east, most likely due to alongshore currents. We predicted the potential range expansion of Balanus perforatus in Korean waters using Genetic Algorithm for Rule-set Prediction (GARP), an environmental niche modeling technique. The results show that much of the southern coastal waters of Korea could be colonized by the spread of the nonindigenous species, but that the west coast is unlikely to be invaded. More sampling on the west coast would enhance the predictability of the model. To our knowledge, this is the first report of its kind for predicting marine nonindigenous species in Korean waters using GARP modeling.

Socio-technical Systems Approach and Innovation Policy (사회.기술시스템론과 과학기술혁신정책)

  • Song, Wichin
    • Journal of Korea Technology Innovation Society
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    • v.16 no.1
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    • pp.156-175
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    • 2013
  • This study examines the approach of socio-technical systems and strategic niche management. It reviews the characteristics of that approach such as multi-level perspectives, the views on technology, and policy orientation. It applies the approach to the long-term vision making in science and technological innovation, socio-technical planning, participatory R&D, and science communication in Innovation policy areas and suggests some policy implications.

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Epiphytic Lichens on Chery trees in Korea. (벗나무에 부착된 지의식물의 생태적 연구)

  • Park Seung Tai
    • The Korean Journal of Ecology
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    • v.2 no.1
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    • pp.1-8
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    • 1978
  • Epiphytic lichens were sampled quantitatively on the cherry trees (Prunus serrulata) at Jeonju and Hadong along both north and south exposures of tat trees. Coverage of lichens was determinated for each species by 10*20cm quadrat. Lichen species diversities such as total diversity (D), mean diversity (D), Shannon diversity (D') and redundancy (R) were estimated according to Brillouin and Shannon equation. The importance value of lichen species was meassured by niche preemption model, The importance value transformed into some fraction k of the niche space. The value of k was compared with aggregation of lichens communities in to areas. The ten most important awariensis, Parmelia incurva, Parmelia crinita, Dirinaria applanta, Parmelia wallichiana, Parmelia austrosinensis and Cetraria platyphylla. The mean coverage epiphytic lichens on north side of tree was higher than of south side in two areas. The species diversities of epiphytic lichen of two areas shows that a change in the value of D' along vertical was not paralled with the D and R. In Kumsan-sa, D, D and D' increased upward along the tree of north exposure, but did not follow this trend in south, However in Sangge-sa, D, D and D' of both sides increased.

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