• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.4
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• pp.1535-1554
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• 2016

This paper proposes a novel channel assignment scheme called multi-cluster based dynamic channel assignment (MC-DCA) to improve system performance for the downlink of dense femtocell networks (DFNs) based on orthogonal frequency division multiple access (OFDMA) and frequency division duplexing (FDD). In order to dynamically assign channels for femtocell access points (FAPs), the MC-DCA scheme uses a heuristic method that consists of two steps: one is a multiple cluster assignment step to group FAPs using graph coloring algorithm with some extensions, while the other is a dynamic subchannel assignment step to allocate subchannels for maximizing the system capacity. Through simulations, we first find optimum parameters of the multiple FAP clustering to maximize the system capacity and then evaluate system performance in terms of the mean FAP capacity, unsatisfied femtocell user equipment (FUE) probability, and mean FAP power consumption for data transmission based on a given FUE traffic load. As a result, the MC-DCA scheme outperforms other schemes in two different DFN environments for commercial and office buildings.

• Journal of the Korea Safety Management & Science
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• v.23 no.1
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• pp.81-94
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• 2021

In SMEs, technological innovation is recognized as an important tool in terms of sustainable growth. This study analyzed the determinants of technological innovation by using the information of the corporate panel DB composed of local SMEs. The internal factors were added with technological innovation capacity and production capacity and the industrial cluster environment was first applied to external factors. Also, whether the industrial cluster environment influences technological innovation through R&D capabilities, the mediating effect was tested with the Sobel Test. Among the internal and external factors, the most important determinant was marketing ability, and a policy was proposed to develop measures to increase R&D capability with mediating effect. Among the technological innovation variables, which are dependent variables, the most determinant factor was the proportion of new product sales. For this, it is considered that additional research such as longitudinal research with the concept of repetition and parallax using the corporate panel DB is necessary.

• Journal of Digital Convergence
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• v.6 no.3
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• pp.35-43
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• 2008

This research was to analyze information network which contributed Anyang Venture Valley's development. And mutual communication between regional innovated companies was the essential factor of this growth. Anyang city with its Knowledge Industry Promotion Agency, KIPA, has first set up communication network, facility and other structures to create basis of communication. For that, they were able to operate various networking and promotion of communication which led to the enforcement of regional innovation in venture businesses. During its innovation, KIPA played a key role as a link between regional Innovated companies, which enabled active interactions between them. Government can verify significance of establishing network base with mediation function for lively communication for promoting innovation capability through Anyang Venture Valley's case.

• Journal of the Korean institute of surface engineering
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• v.39 no.4
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• pp.153-159
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• 2006

Nanodiamond films were deposited on Si substrate by introducing a time dependent on/off modulation of $CH_4\;and\;O_2$ flows in a vertical-type microwave plasma enhanced chemical vapor deposition system. Surface morphology and diamond quality of the film were investigated as a function of the on/off modulation time interval. The diamond nucleation density on the substrate was enhanced under low temperature and low pressure condition. In addition, the diamond nucleation density was enhanced by increasing the on/off modulation time interval. Enhanced diamond quality was noticeable under the condition of a longer on/off modulation time interval. It was suggested that the nanodiamond nuclei formed the cluster formation.

• Journal of the Korean Data and Information Science Society
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• v.19 no.4
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• pp.1081-1089
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• 2008

Beginning in the 2007-2008 season, the men's pro-basketball league changed a foreigner selection method by introducing a draft system which leads to a tryout from the free agency system. Also in the same season, the woman's pro-basketball league changed its system from one that permitted foreign players to one that doesn't allow foreign player participation. The reason for this change is thought to be financial problems. However this institutional change brings about the reduction in the quality of basketball and it will affect spectators in a negative way. The empirical study attempted to analyze the effects which follows an institutional change in Korean men's pro-basketball. The research showed that the men's pro-basketball league wasn't affected at all due to foreigner selection method by a draft system that led to a tryout from the free agency system.

• Journal of Space Technology and Applications
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• v.3 no.2
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• pp.144-153
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• 2023

The existing military satellite communication system was based on geostationary satellites equipped with special communication payloads against enemy's jamming and signal reception. With the advent of new weapon systems such as unmanned systems, the need for low-orbit satellite-based communication system is increasing. This paper introduces various waveform technologies suitable for cube satellite-based communication system and the operational concept of a future military nanosatellite communication system.

• International Journal of Advanced Culture Technology
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• v.6 no.3
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• pp.117-128
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• 2018

This study attempts to derive the possibility of literary therapy through addition and subtraction of emotional codons. It is presumed that the remnants of the emotions formed by the addition and subtraction of emotions will remain in the human body and cause chemical reactions. When this research is activated, cluster of emotional codons will be created by a combination of literary emotions. This is expected to accelerate therapeutic action of sentences by encoding certain emotional codons in AI.

• 축산식품과학과 산업
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• v.4 no.1
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• pp.20-32
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• 2015

• Bulletin of the Korean Chemical Society
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• v.34 no.9
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• pp.2635-2639
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• 2013

The rapid and accurate identification of biological agents is a critical step in the case of bio-terror and biological warfare attacks. Recently, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry has been widely used for the identification of microorganisms. In this study, we describe a method for the rapid and accurate discrimination of Bacillus anthracis spores using MALDI-TOF MS. Our direct in-situ analysis of MALDI-TOF MS does not involve subsequent high-resolution mass analyses and sample preparation steps. This method allowed the detection of species-specific biomarkers from each Bacillus spores. Especially, B. anthracis spores had specific biomarker peaks at 2503, 3089, 3376, 6684, 6698, 6753, and 6840 m/z. Cluster and PCA analyses of the mass spectra of Bacillus spores revealed distinctively separated clusters and within-groups similarity. Therefore, we believe that this method is effective in the real-time identification of biological warfare agents such as B. anthracis as well as other microorganisms in the field.

• Horticultural Science & Technology
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• v.30 no.4
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• pp.378-384
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• 2012

Three Korean-bred strawberry cultivars 'Maehyang', 'Seolhyang', and 'Keumhyang', and a Japanese cultivar 'Tochiotome' were grown in a greenhouse and their physicochemical characteristics were investigated. Fruit weight of 'Seolhyang' and 'Keumhyang' in the first and second fruit clusters were greater than those of other cultivars and that of 'Tochiotome' was the greatest in the fifth fruit cluster. Fruit firmness generally decreased at later fruit clusters, and was the lowest in 'Seolhyang'. The sugars/organic acids ratios in the first and third fruit clusters of 'Maehyang' were 4.9 and 8.0, respectively, representing the highest values among all cultivars. The ascorbic acid content was the greatest in the second fruit cluster for 'Seolhyang', 'Keumhyang', and 'Tochiotome' cultivars and that of 'Maehyang' was the greatest at the third fruit cluster. The anthocyanin content was higher in later fruit clusters and was the highest in 'Keumhyang' overall. Results indicate that Korean cultivars bred for the plastic protected culture, which are intended for very early harvest, showed more desirable physical characteristics in the first and second fruit clusters, while the content of anthocyanin was greater in the fruits from later fruit clusters.