• ALGAE
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• v.31 no.3
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• pp.231-241
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• 2016

We examined the genetic diversity and abundance of picocyanobacteria using barcoded amplicon sequencing approaches and flow cytometry in the East Sea and the East China Sea to determine the distribution patterns of diversity during spring in seas adjacent to the Korean Peninsula. Synechococcus clades I and IV, which have been known as cold-adapted ecotypes, dominated at most stations. However, the relative abundances of the two dominant clades differed in their spatial patterns. Clade I was exclusively dominant in the shelf area of the East China Sea and the north East Sea. However, the dominant genotypes belonging to clade I had different spatial distributions in the two areas and responded oppositely to seawater temperature. The dominance of distinct genotypes under the different ecological conditions suggests the presence of ecologically different ecotypes within the clade. Abundances of clade IV were greater than those of clade I at most stations in the southwest East Sea, showing an apparently different pattern from that of the other areas. A warm-water adapted clade II was observed at significant levels only at stations located in the eastern East China Sea affected by a branch of the warm Kuroshio Current. These results suggest that the physicochemical properties of influencing water masses play an important role in determining the distribution of Synechococcus genotypes.

• Korean Journal of Environment and Ecology
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• v.29 no.3
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• pp.421-430
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• 2015

This study was carried out to understand the ecological variations of macrobenthos communities by construction dikes in the subtidal zone of Chonsu Bay. This study analyzed the distribution of benthos, the dominant species, spatial and temporal changes of benthos communities and benthic pollutions in the subtidal zone of Chonsu Bay. A total of 252 species of subtidal macrobenthos with a density of $681ind./m^2$ were studied. In all the seasons, the species diversity was found to be higher near the mouth of the bay. For all the seasons of the year, Lumbrineris japonica was found to be the most dominant species. These dominant species were found to have positive correlations with species diversity and sedimentary parameters such as organic content in sediments. Dominant species of benthos as well as species composition and diversity showed spatial and temporal distribution patterns.Benthic Pollution Index (BPI) values estimated for the stations near the embankment were in the 4~5 levels, which indicates that the organic matter has been polluted. And as for the stations near the mouth of the bay, the BPI values were in the 1~3 levels, which indicates that the organic matter has been relatively less polluted. According to the SAB-curve analysis, the number of transitional point stations became less in the mouth of the bay.

• Spatial Information Research
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• v.8 no.2
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• pp.233-241
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• 2000

The objective of this study were to develop landscape scale ecosystem assessment model, and apply the model for the assessment of the state and change of ecosystem of the study area, Yongin, Korea. Since natural ecosystem of the site has been deteriorated significantly during recent extensive residential development, it is essential to correctly assess ecosystem of the study site. Traditional ecosystem assessment mainly utilizing intensive field survey requires high cost, but the outcome rarely represents spatial pattern of the regional ecosystems. Ecosystem assesment of landscape scale based on landscape ecology can resolve most of the shortfalls of the traditional approach. The research method can be summarized as follows. First, extensive literature review on such topics as spatial pattern of ecosystem, ecosystem assessment of landscape scale, ecological analysis was carried out. Second, a model for the ecosystem assessment of landscape scale emphasizing spatial pattern of ecosystem was developed. This model evaluates three indicators; ecological integrity and biological diversity, watershed integrity, and landscape resilience of 11 watersheds in the study area. Finally, ecological assessment utilizing two sets of indicators, enhancement of and disturbance of ecosystem stability, was carried out. This assessment method is based on Environmental Monitoring and Assessment Program´s Landscape component(EMAP-L) of EPA(1994). The results of this study are as follows. First, the ecosystem assessment of landscape scale of the study area of Yongin, Korea, showed that escosystems of Tanchun01 and Chungmichun01 watersheds had the worst state in the study site in 1991. On the other hand, the ecosystems of Jinwechun01, Kyunganchun02, and Bokhachun01 watersheds had the most stable ecosystem in 1991. Second, ecosystems of Tanchun01, Shingal reservoir, and Kyunganchun01 watersheds were evaluated to be the worst state in the study site in 1996. And, ecosystems of Jinwechun01 and Gosam reservoir watersheds had the most stable ecosystem. Third, ecosystem of Tanchun01 watershed which incudes Suji residential development project site changed the most drastically between 1991 and 1996. The ecosystem of the watershed the most drastically deteriorated due to it´s proximity to Seoul and Bundang new town.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.360-371
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• 2016

Paul Rudolph's early work in Florida after World War II is a significant example of the regional transformation of typical Modern Architecture through the spatial composition based on the diversity and use of local material and construction methods. Paul Rudolph's concept of a Florida House design is the expression of regional material, construction, and structural system through the spatial extension & connection based on periodical, regional characteristics. The characteristics of the Florida works is the spatial extension & connection design based on the wood structural framework through the various design factors, such as a screen roof, open roof, and internal patio as the spatial extension and link method. Paul Rudolf designed the house using local materials, such as cypress wood and lime block produced near the Florida Area and provided details & technology considering the Florida climate and construction environment. Through studies of Paul Rudolph's Florida works, the Florida Houses can be a prototype of localization, and can be presented as the spatial & technical transformation of design by the historical, cultural, regional background.

• Journal of the Korean housing association
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• v.26 no.2
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• pp.81-88
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• 2015

The purpose of this study was to investigate the possibility of applying the planning characteristics of Neowa houses to contemporary residential structures. Contrary to the popular assumption that traditional Korean houses have decentralized plans, local building traditions observed in Neowa houses show that the diversity among hanoks allows the incorporation of traditional spatial organization into the contemporary residences. By analyzing the spatial organization of Neowa houses, three advantageous planning characteristics were found. First, the presence of indoor wooden floors (maru or daechung) as well as outdoor wooden floors in Neowa houses is practical for Korea's weather marked by humid summers and icy winters. Secondly, the internal orientation of space in Neowa houses is more appropriate in the contemporary context of a highly urbanized society emphasizing family privacy. Thirdly, the flexibility and interchangeability of interior elements can be applied to improve efficiency. By applying the aforementioned characteristics, this study suggests ways to adopt traditional features to improve contemporary residences.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2017.06a
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• pp.49-51
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• 2017

본 논문에서는 ATSC 3.0 시스템의 2x2 MIMO (multiple input multiple output) 방식을 적용한 송수신기 구조에 대해서 살펴본다. ATSC 3.0 시스템의 MIMO 에서 적용된 프리코더 (precoder)는 스트림 결합기(stream combining), IQ 편파 인터리빙 (I/Q polarization interleaving), 위상 홉핑부 (phase hopping)로 구성된다. 또한, ATSC 3.0 의 2x2 MIMO 방식을 사용함으로써 공간 다중화 (spatial multiplexing) 이득과 공간 다이버시티 (spatial diversity) 이득을 얻을 수 있다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.5
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• pp.343-350
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• 2019

Map labels are the most recognizable map elements using the human visual system because they are essentially a natural language. In this study, an experiment was conducted using an eye-tracker to objectively record and analyze the response of subjects regarding visual attention to map labels. A primary building object was identified by analyzing visit counts, average visit duration, fixation counts, and the average fixation duration of a subject's gaze for an area of interest acquired using the eye-tracker. The unmarked rate of map labels in Google map, Naver map, and Daum map was calculated. As a result, this rate exceeded fifty-one percent, with the lowest rate recorded for Google map. It is expected that the results of this study will contribute to an increase in the diversity of research in terms of the spatial cognition approach for map labels, which is more helpful to users than the existing body of work on methods of expression for labels.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.12
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• pp.4600-4616
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• 2021

In cognitive radio networks where unlicensed secondary users opportunistically access to licensed spectrum unused by licensed primary users, spectrum sensing is one of the key issues in order to effectively use the frequency resource. For enhancing the sensing performance in energy detection-based spectrum sensing, spatial diversity based on multiple antennas is utilized. However, the sensing performance can be degraded when antennas are spatially correlated, resulting in inducing the harmful interference to primary users. To overcome this problem, in this paper, an advanced energy detector is proposed. In the proposed sensing method, a weight matrix based on the eigenvalues of the spatial channels without any prior information on the primary signals is defined and utilized. In numerical simulations, it is shown that the proposed detector outperforms the conventional detector with regard to false-alarm and detection probabilities when antenna are spatially correlated.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.07a
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• pp.33-33
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• 2004

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.185-186
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• 2008

We propose an efficient spectrum sensing scheme for cognitive radio systems with multiple antennas. By utilizing the property of multiple receive antennas, spectrum sensing without idle period is possible. Simulation results show that the detection probability is enhanced with the number of receive antennas, which explains the effect of the spatial diversity.