• Journal of Advanced Information Technology and Convergence
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• v.10 no.1
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• pp.1-14
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• 2020

Antenna selection is a method to enhance the performance of spatial multiplexing multiple-input multiple-output (MIMO) systems, which can achieve the diversity order of the full MIMO systems. Although various selection criteria have been studied in the literature, they should be adjusted to the detection operation implemented at the receiver. In this paper, antenna selection methods that optimize the post-processing signal-to-noise ratio (SNR) and eigenvalue are considered for the lattice reduction (LR)-based receiver. To develop a complexity-efficient antenna selection algorithm, the incremental selection strategy is adopted. Moreover, for improvement of performance, an additional iterative selection method is presented in combination with an incremental strategy.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2006.11a
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• pp.66-69
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• 2006

A movement of visitor is a practical means that provides a spatial arrangement of exhibits and validity to that principle. Thus, an exhibition of a museum cannot be completed by an intrinsic value of exhibition itself. Thereby the purpose of this thesis is finding out the relationship between the visitors' pattern and spatial configuration in museum. As a result, as for the visitors' movement, it was grasped that diversified patterns of movements could appear in case the selections of courses are diversified within the environment in that the general understanding about the spaces was easy. That is, the exhibition environment in that general understanding about the spaces is easy because of the low depth of the exhibition space recognized from the entrance of the exhibition space and composition of exhibition space with diversified selections of courses may induce diversity of viewing patterns. That is, it may mean that in such composition of space, visitors may establish viewing courses based on their own purposes of viewing and preference thus they form individual spatial experiences themselves.

• Korean Journal of Remote Sensing
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• v.39 no.4
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• pp.459-466
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• 2023

In the last decade, artificial intelligence's dramatic advancement with the development of various deep learning techniques has significantly contributed to remote sensing fields and satellite image applications. Among many prominent areas, super-resolution research has seen substantial growth with the release of several benchmark datasets and the rise of generative adversarial network-based studies. However, most previously published remote sensing benchmark datasets represent spatial resolution within approximately 10 meters, imposing limitations when directly applying for super-resolution of small objects with cm unit spatial resolution. Furthermore, if the dataset lacks a global spatial distribution and is specialized in particular land covers, the consequent lack of feature diversity can directly impact the quantitative performance and prevent the formation of robust foundation models. To overcome these issues, this paper proposes a method to generate benchmark datasets by simulating the modulation transfer functions of the sensor. The proposed approach leverages the simulation method with a solid theoretical foundation, notably recognized in image fusion. Additionally, the generated benchmark dataset is applied to state-of-the-art super-resolution base models for quantitative and visual analysis and discusses the shortcomings of the existing datasets. Through these efforts, we anticipate that the proposed benchmark dataset will facilitate various super-resolution research shortly in Korea.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.11
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• pp.985-991
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• 2015

This paper proposes appropriate locations for site diversity to provide stable satellite communication service in Korea. For this purpose, we analyzed rainfall rate data measured by KMA for 5 years at 88 sites, and the variations of simultaneous occurrence of rainfall rate in pairs of sites using the correlation coefficient. This paper provided contour maps of the spatial ditstribution of rainfall rate correlation, and proposed information on the optimum sites/regions for the operation of muti-uplink satellite systems, in 4 cities which were principal in field of satellite communication in Korea.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.3
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• pp.39-50
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• 2015

This research selected Daegu Metropolitan City representing a combination of natural space and urban space for this case study. To achieve this, a prerequisite was to set up an optimal block size to evaluate landscape diversity of the research site by using a RPR-Area Curve. Further, landscape diversity evaluation was conducted based on land cover map by using FRAGSTATS to analyze spatio-temporal changes. Notably, this research regarded it as the most significant to set forth criteria in order to apply landscape diversity to the development plans of the newtown and outskirt of a city under high pressure development. Results derived from this research are summarized as follows. According to the results derived from establishing the optimal block size, a size about $2km^2$ was analyzed to measure landscape diversity of the research site. Also, according to the results derived from land diversity evaluation based on land cover map, land diversity was highly measured around urban stream such as Nakdong River and Geumho River, and in particular, the value of landscape diversity was measured considerably high around the urban parks. Results derived from analysis on spatio-temporal changes of land diversity demonstrated that a certain level of urban development exerted a positive effect on an increase in land diversity, but consistent urban development lowered a value of landscape diversity. Results derived from regression analysis to set forth the optimal urban space showed that an urban area of a space about $2km^2$ exerted a positive effect at a rate of about 0~43.3% and a negative effect at a rate about 43.3~100%. In conclusion, the results of this research are considered to provide important basic data for future urban and landscape planning. Nonetheless, as only the layout on the 2D plane was analyzed in this research, further research in future is required to complexly consider diverse factors such as height of structure and change in visible real area arising from geographical features.

• Journal of Ecology and Environment
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• v.43 no.4
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• pp.400-420
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• 2019

The aims of the study were to analyze (1) the effects of Prosopis juliflora (Prosopis) on the spatial distribution and soil seed banks (SSB) diversity and density, (2) the effects of environmental factors on SSB diversity and density (number of seeds in the soil per unit area), and (3) the effects of animal fecal droppings on SSB diversity, density, and dispersal. Aboveground vegetation data were collected from different Prosopis-infested habitats from quadrats (20 × 20 m) in Prosopis thickets, Prosopis + native species stand, non-invaded woodlands, and open grazing lands. In each Prosopis-infested habitats, soil samples were collected from the litter layer and three successive soil layer, i.e., 0-3 cm, 3-6 cm, and 6-9 cm. Seeds from soil samples and animal fecal matter were separated in the green house using the seedling emergence technique. Invasion of Prosopis had significant effects on the soil seed bank diversity. Results revealed that the mean value of the Shannon diversity of non-invaded woodlands was being higher by 19.2%, 18.5%, and 11.0% than Prosopis thickets; Prosopis + native species stand and open grazing lands, respectively. The seed diversity and richness, recovered from 6-9-cm-deep layer were the highest. On the other hand, the density of Prosopis seeds was the highest in the litter layer. About 156 of seeds/kg (92.9%) of seeds were germinated from cattle fecal matter. However, in a small proportion of seedlings, 12 of seeds/kg (7.1%) were germinated from shot fecal matter. Thus, as the seeds in the soil were low in the study areas, in situ and ex situ conservation of original plants and reseeding of persistent grass species such as Cynodon dactylon, Cenchrus ciliaris, Chrysopogon plumulosus, and Brachiaria ramosa are recommended.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.2
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• pp.154-170
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• 2022

The zooplankton composition, abundance, community structure, and species diversity in the major commercial fishery species spawning grounds in the southern coast of Korea were investigated in this study. A total of 80 taxa were sampled, with the mean abundance range of 5,612-11,720 ind. m^-3 and the mean biomass range of 41.6-1,086.8 mg m^-3. The dominant species were Paracalanus copepodites, Paracalanus parvus s. l., Oithona copepodites, Paracalanus nauplii, Noctiluca scintillans, Oithona similis, and Ditrichocorycaeus affinis. The species diversity indices were highest in August, suggesting that diversity is influenced by neritic and oceanic warm-water species. A cluster analysis with non-metric multidimensional scaling (nMDS) revealed three groups of zooplankton communities. The April and May samples clustered into Group A, having the highest mean total zooplankton abundance and lowest species diversity, consisting mainly of temperate species located in the middle region of the southern coast of Korea. Cluster Group B was from the early summer season (June) and contained the highest species diversity with some oceanic and neritic zooplankton species. Cluster Group C from the summer season (July and August) mainly comprised P. parvus s. l. and O. similis. The redundancy analysis (RDA) indicated that abundance is positively correlated with salinity, and chlorophyll-a concentrations.

• Korean Institute of Interior Design Journal
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• v.20 no.3
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• pp.206-214
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• 2011

The premise of this study is that an ultimate objective in planning an exhibition space is visitors' experiences created by a result of their first-hand experiences and responses within an exhibition space, and this result can be recognized in the visitors' movement. Thus, the exhibition layout that can directly affects viewers' main line of flow and movement patterns was examined vis--vis a mutually complementary relation in a triangular composition with the structure of exhibition space and the exhibition contents. This study, with the subjects of standing exhibit halls of Gwacheon National Science Museum, Daejeon National Science Museum, and Tokyo National Museum of Emerging Science and Innovation, analyzed 'the correlation between the configuration of the exhibition area and the visitors' movement. The targeted subjects were analyzed from the perspectives of type of architectural space and organization of the exhibition method, and the purpose of this study was to find a spatial evidence to predict the spectator movement formed within the exhibition halls of science museums. The main indicators used are: Based on the investigation/analysis as described above, the following conclusion could be drawn. Diversity of exhibition environment and spectator movement: besides the two big categories of the types of architectural space and types of exhibition method, the construction of vertical circulation and size and shape of the exhibition space, distribution characteristics of exhibition medium, organization of symbolic space and such other diverse organizations and combinations of exhibition environment are implied to have the capability to alter the scope and degree of predicting spectator movement. As an example, the types of architectural space comprising the wide-area viewing circulation was found to be able to change the system of planar circulation according to the composition of vertical circulation. Along with this, it was implied that the format of architectural space influences the form of the exhibition space, and may also act as a factor directly influencing the diversity and arrangement of the exhibition methods. That is, the spatial elements comprising the exhibition environment acts inter-complexly, and exhibits characteristics of limiting or controlling spectator movement.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.8A
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• pp.592-599
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• 2009

In this paper, we consider multiuser multi-input/multi-output antenna systems with zero-forcing receivers in downlink. In this case, to exploit multiuser diversity, spatial-division multiple access (SDMA) system allows to assign different users to a part of transmit antennas at the base station whereas spatial-division multiplexing (SDM) system assigns all antennas to single user's data stream. In this paper, we present analytical frameworks to evaluate performance of these systems. We first analyze the performance of these two systems by deriving closed-form expressions of achievable throughput. Numerical results show that the derived expressions are very tight. In addition, we approximate the capacity expression of SDM and SDMA systems and compare the SDM with the optimal case.

• Journal of Families and Better Life
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• v.26 no.5
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• pp.195-209
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• 2008

The purpose of this study was to provide basic information about design guidelines of activity areas in elderly nursing facilities. For the study, the activity areas of 44 facilities in Korea were investigated to categorize their spatial compositions and forms, and then a case study about 19 facilities was conducted to analyse their hierarchical characteristics. The results of the study were as follows: First, the major type of spatial composition among 44 research facilities was concentration, but compartment type was the main among unit-care facilities. By the year, all the types of spatial composition were evenly distributed during recent five years, while concentration type was about 40% before 2003. Second, the major form of activity areas was hall or corridor extension for large group. But there was more alcove or separation form among small group spaces. Third, in the case analysis about hierarchical characteristics, hall and corridor extension form met the requirements of accessibility and openness of public and semi-public areas. On the other hand, separation form had a problem in satisfying both requirements. The semi-private areas, which were around the elderly bedrooms and the elderly were able to watch activities in, were not sufficient in many facilities. Fourth, the division of public and semi-public area was mainly by furniture, and the individuality of semi-private area was defined by dead-end place and corner seats of the window or the corridor. The diversity of semi-private area was likely to be appeared in connection or distribution type. On the basis of the results, the basic design guidelines for activity areas in elderly nursing facilities could be suggested as follows: On the whole, connection or distribution type in spatial composition is more efficient for hierarchical flow than concentration or compartment type is, especially in Korean facilities having many elderly residents per floor. In detail, the design of public and semi-public area should be focused on their openness and accessibility. The recommended forms of activity areas were hall or corridor extension in public area, and living room, corridor extension, or large corridor in semi-public area to effectively function as large or small group spaces. In semi-private areas, the spatial diversity and individuality should be considered.