• 대한원격탐사학회지
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• 제27권5호
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• pp.601-611
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• 2011

최근 인구집중으로 인한 도시개발 및 사회기반 시설의 확충 등의 인위적 현상과 지구온난화 및 가뭄, 홍수, 산불 등 자연적 현상 등 다양한 요인으로 인해 토지피복 변화가 발생하고 있다. 이러한 토지피복변화의 원인과 영향, 그리고 탐지방법에 대한 다양한 연구가 진행되고 있는데, 기존 연구들은 대부분 주어진 임계치를 기준으로 '변화' 또는 '무변화'의 양분된 결과를 도출한다. 따라서 본 연구에서는 확률에 기초하여 공간자기상관과 핫스팟 탐지를 결합한 변화탐지 방법을 제시하고자 한다. 또한 기존의 핫스팟 탐지 알고리즘인 AMOEBA(A Multidirectional Optimal Ecotope-Based Algorithm)에서 나타나는 과다탐지의 경향을 개선하여 핵심적인 토지피복 변화의 핫스팟을 탐지하는 AMOEBA-CH(core hotspot)를 개발 및 적용하였다. 본 연구에서는 토지피복 변화의 확률과 공간자기상관에 기초한 픽셀 간의 공간적 상호작용을 고려하였으며, AMOEBA-CH의 인접-우세 모형을 통해 토지피복 변화의 핵심적인 핫스팟을 탐지하고자 한다. 본 연구에서 제시한 방법의 가용성을 테스트하기 위해 남한지역의 2000년과 2008년의 NDVI자료를 이용하여 토지피복 변화의 핫스팟 탐지를 수행하였다.

• 한국환경복원기술학회지
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• 제9권5호
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• pp.32-40
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• 2006

This study's objects are to suggest effective forest community-level management measures by identifying the vulnerable forest vegetation communities types to climate change through a comparative analysis with present forest communities identified and delineated in the Actual Vegetation Map. The methods of this study are to classify the climatic life zones based on the correlative climate-vegetation relationship for each forest vegetation community, the Holdridge Bio-Climate Model was employed. This study confirms relationship between forest vegetation and environmental factors using Pearson's correlation coefficient analysis. Then, the future distribution of forest vegetation are predicted derived factors and present distribution of vegetation by utilizing the multinomial logit model. The vulnerability of forest to climate change was evaluated by identifying the forest community shifts slower than the average velocity of forest moving (VFM) for woody plants, which is assumed to be 0.25 kilometers per year. The major findings in this study are as follows : First, the result of correlative analysis shows that summer precipitation, mean temperature of the coldest month, elevation, soil organic matter contents, and soil acidity (pH) are highly influencing factors to the distribution of forest vegetation. Secondly, the result of the vulnerability assessment employing the assumed velocity of forest moving for woody plants (0.25kmjyear) shows that 54.82% of the forest turned out to be vulnerable to climate change. The sub-alpine vegetations in regions around Mount Jiri and Mount Seorak are predicted to shift the dominance toward Quercus mongolica and Pinus densiflora communities. In the identified vulnerable areas centering the southern and eastern coastal regions, about 8.27% of the Pinus densiflora communities is likely to shift to sub-tropical forest communities, and 3.38% of the Quercus mongolica communities is likely to shift toward Quercus acutissima communities. In the vulnerable areas scattered throughout the country, about 8.84% of the Quercus mongolica communities is likely to shift toward Pinus densiflora communities due to the effects of climate change. The study findings concluded that challenges associated with predicting the future climate using RCM and the assessment of the future vulnerabilities of forest vegetations to climate change are significant.

• 한국수산과학회지
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• 제47권5호
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• pp.659-666
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• 2014

Our aim was to compare the community structure of fish in the coast of Wando Island between 2001 and 2013. Using a gape net with wings, we collected 61 taxa, wherein the most dominant species was Engraulis japonicus. The sea temperature in the middle layer of the survey station in 2001 (after June) was obviously higher than that in 2013, which was < $20^{\circ}C$. Except for Thryssa kammalensis in 2013, the log transformed individuals of seven dominant species, selected using a SIMPER (similarity-percentages procedure) analysis, decreased. Decreases in the individuals of Gobiidae spp., the warm-water species Trichiurus japonicus and Conger myriaster, and the migratory species Syngnathus schlegeli, Setipinna taty and Sardinella zunasi, which arrive in the southern coastal waters of Korea during summer-autumn, could be due to decreasing sea temperature in 2013. Thus, fish species diversity, estimated from rarefaction and k-dominance curves, declined in the coastal waters of Wando Island from 2001 to 2013, resulting in a significant difference in fish community structure.

• 대한기계학회논문집B
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• 제23권2호
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• pp.198-209
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• 1999

This study reports the selection of dependent variables for momentum equations in general curvilinear coordinates. Catesian, covariant and contravariant velocity components were examined for the dependent variable. The focus of present study is confined to staggered grid system Each dependent variable selected for momentum equations are tested for several flow fields. Results show that the selection of Cartesian and covariant velocity components intrinsically can not satisfy mass conservation of control volume unless additional converting processes ore used. Also, Cartesian component can only be used for the flow field in which main-flow direction does not change significantly. Convergence rate for the selection of covariant velocity component decreases quickly as with the increase of non-orthogonality of grid system. But the selection of contravariant velocity component reduces the total mass residual of discretized equations rapidly to the limit of machine accuracy and the solutions are insensitive to the main-flow direction.

• Journal of Forest and Environmental Science
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• 제25권1호
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• pp.49-55
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• 2009

The present study analyses the effect of land use on the vegetation of some desert ecosystems in Abu Dhabi, United Arab Emirates (UAE). Three sites were selected to represent different types of land use, inside Umm Al-Banadeq forest, outside the forest and along Abu Dhabi-Al Ain Trucks Road. In total, fifty-two stands were examined; including a matrix of 14 species ${\times}$ 52 stands. Based on species cover data, stands were classified using TWINSPAN and ordinated using DCA. Four vegetation groups were generated at level three of classification. Zygophyllum mandavillei was dominant in most vegetation groups; Heliotropium bacciferum dominated vegetation groups inhabited the forest. Species richness, species turnover, relative evenness and relative concentration of dominance of forest vegetation groups were 2.8, 5.7, 0.7, and 2.0, respectively. The differences were attributed to both natural variability and forestry-induced changes, including change in land use, drainage and ploughing and shading by trees. Vegetation group inhabited Abu Dhabi-Al Ain Trucks Road, that were dominated by Haloxylon salicornicum and Zygophyllum mandavillei have high total cover (8.8 m per $m^{-1}$). Most community and vegetation attributes were significantly higher inside the forest than outside. Human interventions and environmental factors affected species diversity and abundance of these communities.

• Journal of Plant Biology
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• 제14권3호
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• pp.1-20
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• 1971

Ecological factors limiting Stipa pulchra have been determined in experimental gardens and at several sites in the hills south and east of Monterey, California. The Stipa pulchrafacies of Valley Grassland communities were found to be dominated by that species, though a total of 36 grasses and forbs were collected and identified. Basal area was not large, but aerial cover by Stipa alone averaged over 50 per cent. Across an ecotone between a Stipa association and the California Annual Type a sudden and dramatic change was recorded. Soil measurements there, and in other nearby areas, showed a much higher clay content with more available water and elemental phosphorus at the Stipa sites. Germination of Stipa seeds was high under all laboratory and field conditions, though growth of seeldings was highly variable. Seedlings grown in Stipa woil with an abundance of water were vigorous and reached anthesis the first year. In other soils they grew less, and when grown in competition with Avena fatua they scarcely grew at all. These findings indicate that when established on desirable soils, Stipa competes well and apparently precludes the dominance of Avena fatua and other large annual grasses. On the other hand, because of a lack of vigor in its seedlings, Stipa cannot reinvade the rich more friable soils on which it was once found, and on which it was shown to grow satisfactorily. This supports the contention that Sipa pulchra was the dominant grass through much of the Valley Grassland and Foothill Woodland, but also indicates that well-drained soils and those poor in mineral nutrients probalby never supported such associations.

• Journal of Plant Biology
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• 제37권1호
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• pp.1-8
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• 1994

The effects of fetilization on the structure and function of an early successional Miscanthus sinensis grassland were investigated in an old-field ecosystem at Honjo city, Saitama Prefecture, Japan from 1981 to 1982. Compared to control plot, life form composition of treatment plot was characterized by a decrease of phanerophytes and an increase of hemicryptophytes. Fertilization had a beneficial effect on the growth in aboveground phytomass of M. sinensis, the dominant species. However, it did not cause a change in the total number of stems of M. sinensis. Annual increment of patch diameter of M. sinensis was estimated to be 6-8 cm on an average and there was no significant differecne in the growth rate of patch size between fertilized and nonfertilized plots. To estimate the aboveground phytomass of M. sinensis, several non-destructive parameters were examined. As a result, the patch size showed a high correlation with aboveground phytomass. Thus the patch size was suggested to be most applicable to its estimation. Diversity indices based on phytomass data of component species were increased slightly by fertilizatin, because relative dominance of some other species, especially of Artemisia princeps increased, while that of M. sinensis decreased. Fertilizer application resulted in a decrease in the total number of species.

• 생명과학회지
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• 제16권7호
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• pp.1097-1103
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• 2006

Community structure varies not only in space but also in time. We stand in one position which located at Sinhung-ri, Sacheon-ci and observe the flora of area as time passes. This area begins after disturbance on sites where organisms are already present like secondary succession. In 2001, there are invaded by Trapa japonica, Salvinia natans, and Potamogon cristatus. Four or five years later, this abandoned areas support of clover, pine, and oak, resulting in a shifting pattern of species dominance and diversity through time. Patterns of community structure such as species composition and ecological diversity have shown through seasons and five years, that is the topic of this study. The values of turnover (TO) were changes through time intervals at three regions. The gradual and seemingly directional change in the structure of the community through time from aquatic like to field. Thus, we can observe the process of secondary succession at Sinhung-ri in the very short time.

• 한국환경과학회지
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• 제25권5호
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• pp.615-623
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• 2016

Bird species (BS) of the Nakdong River estuary (NRE) were selected to suggest conservation and management strategies, taking habitats and major threats into consideration. Five BS (Cygnus spp., Calidris alpina, Sterna albifrons, Fulica atra, and Anser fabalis) were selected following analysis of their dominance, national importance, seasonality, taxonomic group, and distribution within the NRE. The BS comprise two winter birds, one summer, one passage bird, and one resident bird. They can also be classified into four taxonomic groups: two under ducks and geese (Anatidae), and one each under gulls (Laridae), shorebirds (Scolopacidae), and diving birds (Rallidae). The results show that BS could be a useful tool in guiding estuary management because their habitats are clearly distinct, and include important areas of the NRE. A reduction of feeding and resting places-such as tidal flats, Scirpus planiculmis habitat, and agricultural farmland-and climate change are major threats to BS, therefore countermeasures to such threats should be considered in future estuary management plans.

• 한국유통학회지:유통연구
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• 제1권1호
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• pp.65-81
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• 1996

Despite the impressive economic growth over the past several decades, Korea's distribution sector has remained quite underdeveloped. Until recently, management of the marketing channels also has been staying at an unsophisticated level. The Korean marketing channel system is largely characterized by 1) undifferentiated channel types among the competing manufacturers, 2) dominance by the manufacturers over the other channel members, 3) high level of conflicts among the channel members, 4) inefficient marketing information system, and 5) lack of managers properly trained in channel operation and management. Currently, major change factors emerged and has begun to directly affect the Korean marketing channel system. The most salient changes surrounding the Korean marketing channel system are 1) complete opening of the marketing channels for the foreigners, 2) emergence and spread of new types of channels 3) adoption of advanced information technology by the various channel members, 4) increase in flexibility in production and supply systems, 5) shift of power toward the retailers away from the manufacturers, 6) growing trend for cooperation and alliance among the traditional marketing institutions. To these changes the manufacturers have been reacting, rather than proacting, mostly using defensive measures. The proactive measures that are recommended on behalf of the manufacturers include 1) installation of the strategic channel management system, 2) development of the skills for efficient interorganization management, 3) investing in efficient system for marketing information and logistics management, 4) more efficient management of brands, and 5) maintenance of price-competitiveness.