• Journal of Industrial Technology
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• v.33 no.A
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• pp.93-99
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• 2013

Shotcrete has been referred to as gunite, pneumatically applied mortar or concrete, sprayed concrete or mortar. There are sound reasons why sprayed mortar is one of the best portland cement based material for repairing old concrete structures. However, it is difficult to find the research results on the latex-modified mortar nevertheless on the impact of air onto the fresh and hardened properties of latex-modified mortar. So, the main experimental program included strength test, slump test, rapid chloride permeability test, image analysis for air void system, and chemical attacks with the main experimental variables of latex content, fine aggregate content, water-cement ratio, and air foamer content.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.382-385
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• 1995

Electrical properties such as tracking resistance, dielectric constant, $tan\delta$, and volume resistivity, and mechanical properties such as tensile, and strength, and % elongation were measured with the alumina trihydrate filled with EPDM. The results were dicussed in terms of the effect of hydroxyl group. The test results show that the tracking resistance of EPDM improves with the increase in ATH content, whereas volume resistivity, dielectric constant, $tan\delta$ decrease wi th increasing ATH content due to polar nature of ATH. In the charge accumulation characteristics, the homocharge is formed in pure EPDM, and as the ATH content increases in the EPDM compound, the amount of homocharge decrease.

• Journal of Korea Game Society
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• v.17 no.4
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• pp.7-16
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• 2017

In this thesis, the objective is to identify and analyze trends in the evolution of virtual reality in the midst of the trend of digital content and the trend of the 4th industrial revolution. The analysis is divided into devices, development, distribution platforms and content fields, which are divided into active, static, and classical content and trend. This thesis is meaningful as a basic material in the planning stage of virtual augmented reality contents.

• Journal of Korea Society of Industrial Information Systems
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• v.5 no.2
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• pp.9-15
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• 2000

In this paper, we proposed a content-based image retrieval method using color and object's complexity for indexing of image database. Generally, the retrieval methods using color feature can not sufficiently include the spatial information in the image. So they are reduced retrieval efficiency. Then we combined object's complexity which extracted from chain code and the conventional color feature. As a result, experiments shooed that the proposed method which considers the shape feature improved performance in conducting content-based search.

• Elastomers and Composites
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• v.55 no.4
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• pp.263-269
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• 2020

Novel flexible terpolymers with a reactive moiety were synthesized by coordination polymerization with a metallocene catalyst and a cocatalyst system. C2-symmetric rac-Et(Ind)2ZrCl2 and tri-iso-butylaluminum/dimethylanilinium tetrakis (pentafluorophenyl) borate were employed as the catalyst and cocatalyst, respectively. We synthesized reactive terpolymers consisting of ethylene, a high α-olefin content (1-hexene, 1-octene, 1-decene, and 1-dodecene), and divinylbenzene. The structure and composition of the terpolymers were characterized by 1H-nuclear magnetic resonance analysis. The catalytic activity, polymer yield, molecular weight, and molecular weight distribution were measured as functions of the chain length and high content of α-olefins. Furthermore, the thermal properties and crystallinity of the terpolymers were determined by differential scanning calorimetry and wide-angle X-ray scattering.

• International Journal of Knowledge Content Development & Technology
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• v.12 no.1
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• pp.85-104
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• 2022

In this study, in line with the era of the fourth industrial revolution, general concepts, technologies, trends, and examples of virtual reality and augmented reality were examined, and based on this, a plan that could be applied to libraries in the future was proposed. As a result of the study, first, it is necessary to construct a smart space as an experiential play space that can satisfy cultural desires transcending time and space by providing immersive contents using 4th technology such as VR and AR. Second, it is necessary to expand experiential cultural support services through VR, AR and MR. Third, to develop educational contents based on augmented reality technology. In order to apply and activate virtual reality and augmented reality in libraries in the future, based on a survey of librarians and users of public libraries, a survey on the application status, satisfaction, and demand of current public libraries should be conducted.

• Fourth Industrial Review
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• v.4 no.1
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• pp.29-36
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• 2024

Purpose: This study is a prior study for expanding the science museum's online services. Based on case studies, we propose an online service for science museums in the future. Research design, data, and methodology: This study analyzed online-based science museums services trends. The data was collected based on the cases of five national science museums. To understand the characteristics of science museum's online services, we analyzed the status of digital content provided by each science museum and the operation method of online special exhibitions. Result: The national science museums provided online services through virtual science museums, SNS, and YouTube. However, the services still imposed limitation on facilitating active learning for visitors. In the case of SNS and YouTube, it is only a one-time promotional tool. Conclusion: This study suggests the need for concrete measures to utilize the abundant content accumulated so far in actual education. Additionally, it emphasizes the importance of content development incorporating new platforms.

• Journal of Korea Foundry Society
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• v.25 no.5
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• pp.216-220
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• 2005

High ductility Al-Mg alloys often contain some Mn and Si, however the effects of these minor alloying elements on various properties of alloys have not been fully understood. In this study the castability and mechanical properties of Al-5%Mg alloy were investigated according to the addition of Mn and Si. The fluidity of the alloys was generally increased by increasing Si or Mn contents. The feedability was also increased by increasing Si content, but it was rather decreased by increasing Mn content. Both the tensile strength and the ductility appeared to be deteriorated by Si addition, while they were found to be improved by Mn addition.

• Korean Journal of Materials Research
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• v.17 no.8
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• pp.397-401
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• 2007

Fe based SOFC(Solid Oxide Fuel Cell) interconnector was fabricated by using the spark plasma sintering process and its microstructure and mechanical properties were investigated in this study. To fabricate the interconnector, the Fe-26Cr powder was mixed with the Ag (5, 10, 20wt.%) particles. In the Fe-26Cr-Ag sintered bodies, the Ag particles were almost dispersed at the grain boundary of the Fe-26Cr. The sintered bodies have the density of 87.2-97.5%, the density increases with increasing Ag content at sintering temperature of $850^{\circ}C$. Also, the compressive yield strength increases with increasing Ag content at the same sintering temperature.

• Korean Journal of Breeding Science
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• v.42 no.1
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• pp.11-22
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• 2010

The population structure of a domesticated species is influenced by the natural history of the populations of its pre-domesticated ancestors, as well as by the breeding system and complexity of breeding practices implemented by humans. In the genetic and population structure analysis of 122 South Asia collections using 29 simple sequence repeat (SSR) markers, 362 alleles were detected, with an average of 12.5 per locus. The average expected heterozygosity and polymorphism information content (PIC) for each SSR locus were 0.74 and 0.72,respectively. The model-based structure analysis revealed the presence of three clusters with the 91.8% (shared > 75%) membership, with 8.2% showing admixture. The genetic distances of Clusters 1-3 were 0.55, 0.56, and 0.68, respectively. Polymorphic information content followed the same trend (Cluster 3 had the highest value and Cluster 1 had smallest value), with genetic distances for each cluster of 0.52, 0.52, and 0.65, respectively. This result could be used for supporting rice breeding programs in South Asia countries.