• International Journal of Advanced Culture Technology
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• v.10 no.4
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• pp.460-469
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• 2022

Increasing interest in the metaverse world these days, interest in realistic content such as 3D displays is growing. In particular, hologram images seen in movies provide viewers with an immersive display that cannot be seen in conventional 2D images. Since the first discovery of holography by Dennis Gabor in 1948, this technology has developed rapidly. Spatially, this beginning of technology like Optical hologram called analog hologram and Digital hologram such as computer-generated hologram (CGH). In analog and digital holograms, a recording angle and a recording wavelength are having important role when reproducing and display hologram. In the hologram, diffraction of light causes by unexpected formed by the synthesis from interference with object and reference light. When recording, the incident light information and mismatched reproduction light reconstruct the hologram in an undesirable direction. Reproduction light that is out of sync with incident light information with initial condition of recording will cause reconstructed image in an undesirable direction. Therefore, we analyze the holographic interference pattern generated by hologram recording in volume holograms using photopolymer and analyze the characteristics that vary depending on the angle of the reproduced light. This is expected to be used as a basic research on various holographic application that may cause as holograms are applied to industries in the future.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.2
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• pp.193-199
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• 2023

The purpose of this paper is to solve the difficulties of experimental education by using AR science experiments in class, prevent safety accidents, and maximize immersion through multilateral experiences to induce active participation. The problems with educational realistic content currently being developed were (1) the lack of exploratory content practically available in class, (2) the end of most applications with one-time content, and (3) the inability to interact between teachers and students. To solve these problems, we develop AR experiments according to the curriculum. It is developed so that teachers and students can use it together through the function that teachers can manage students.

• International Journal of Knowledge Content Development & Technology
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• v.13 no.2
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• pp.89-104
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• 2023

The purpose of this study was to propose ways to improve the library field practice of Department of Library and Information Science to improve the field environment and educational content, enhance students' field practice, increase efficiency, and increase students' satisfaction. To this end, a survey and interview survey were conducted on students who were going to do field training, and the results are as follows. First, students were well aware of what preparations should be made at school before going to field training. Second, students showed high awareness of their rights guarantees and requests for action in the event of problems at field training institutions. Third, students showed a high demand that field training should guarantee the minimum hourly wage. What is an issue in this regard is that policies that can satisfy both the burden of universities for continuous student guidance and evaluation, the burden of training institutions to conduct education while paying practical expenses, and the rights of students to be protected. This study was aimed at students, but it seems that realistic field practice policies should be presented from various angles as research on government ministries or university authorities is added.

• Geomechanics and Engineering
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• v.36 no.2
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• pp.145-156
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• 2024

The mechanical properties of the concrete-frozen soil interface play a significant role in the stability and service performance of construction projects in cold regions. Current research mainly focuses on the precast concrete-frozen soil interface, with limited consideration for the more realistic cast-in-place concrete-frozen soil interface. The two construction methods result in completely different contact surface morphologies and exhibit significant differences in mechanical properties. Therefore, this study selects silty clay as the research object and conducts direct shear tests on the concrete-frozen soil interface under conditions of initial water content ranging from 12% to 24%, normal stress from 50 kPa to 300 kPa, and freezing temperature of -3℃. The results indicate that (1) both interface shear stress-displacement curves can be divided into three stages: rapid growth of shear stress, softening of shear stress after peak, and residual stability; (2) the peak strength of both interfaces increases initially and then decreases with an increase in water content, while residual strength is relatively less affected by water content; (3) peak strength and residual strength are linearly positively correlated with normal stress, and the strength of ice bonding is less affected by normal stress; (4) the mechanical properties of the cast-in-place concrete-frozen soil interface are significantly better than those of the precast concrete-frozen soil interface. However, when the water content is high, the former's mechanical performance deteriorates much more than the latter, leading to severe strength loss. Therefore, in practical engineering, cast-in-place concrete construction is preferred in cases of higher negative temperatures and lower water content, while precast concrete construction is considered in cases of lower negative temperatures and higher water content. This study provides reference for the construction of frozen soil-structure interface in cold regions and basic data support for improving the stability and service performance of cold region engineering.

• Journal of Broadcast Engineering
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• v.20 no.1
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• pp.68-81
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• 2015

Owing to the latest development of component and media processing technologies, UHDTV as a successor of the HDTV is expected that this will be coming soon realization. Accordingly, an audio technology that provides a 5.1-channel surround sound in home should be contemplating on what services should be provided with the advent of UHDTV era. In fact, however, the market of 5.1-channel audio is struggling, due to the difficulty of installation and maintenance of the multi speakers in a home. Meanwhile, the movie sound market for a long time been used in 5.1 and 7.1-channel sound formats, have changed as Dolby ATMOS, IOSONO, AURO3D etc. are launched one after another with the introduction of hybrid audio technologies that include the ceiling and object-based sounds. This very object-based audio technology is assured to be introduced in the home theater and broadcast audio market, and this change in audio technology is expected to be a breath of pioneering technological advances and market growth from the channel-based audio market that lacks flexibility. In this paper, we will investigate a suitable realistic audio solution for UHDTV, and introduce hybrid audio technologies, which is expected to be an audio technology for UHDTV, and we will describe the hybrid audio content format and reproduction methods in a home and consider the future prospects of realistic audio.

• Journal of the Korean Geotechnical Society
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• v.21 no.9
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• pp.53-64
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• 2005

For geotechnical design in practice, soils are, in general, assumed to behave as a linear elastic or perfect plastic material. More realistic geotechnical design, however, should take into account various factors that affect soil behavior in the field, such as non-linearity of stress-strain response, stress history, and water content. In this study, a series of laboratory tests including triaxial and resonant column tests were peformed with sands of various silt contents, relative densities, stress states, OCR and water contents. This aims at investigating effects of various factors that affect strength and stiffness of sands. From the results in this study, it is found that the effect of OCR is significant for the intermediate stress-strain range from the initial to failure, while it may be ignored for the initial stiffness and peak strength. For the effect of water content, it is observed that the initial elastic modulus decreases with increasing water content at lower confining stress and relative density At higher confining stresses, the effect of water content Is found to become small.

• Journal of Practical Engineering Education
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• v.15 no.2
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• pp.519-528
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• 2023

Recently, for the preservation and transmission of cultural heritage, various researches and content development based on technologies such as virtual reality, augmented reality, and extended reality, which are the core technologies of the 4th industrial revolution era, are being conducted. Intangible cultural heritage is variable, unlike tangible cultural heritage, so it changes greatly depending on time and space, and as a result, it is in danger of being discontinued due to the aging and death of the inheritors. In this study, the current status and cases of related realistic content production were collected and analyzed, focusing on statistical data, intangible cultural heritage training centers through search portals, and platform cases. As a result of the analysis, it was found that overall, there were very few cases of use in content and transfer education using intangible cultural heritage. Through this study, we will consider ways to revitalize the effective transfer education of intangible cultural heritage that is on the verge of being cut off from transmission.

• Journal of Broadcast Engineering
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• v.27 no.5
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• pp.654-664
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• 2022

Immersive content overcomes spatial limitations through convergence with extended reality, artificial intelligence, and photogrammetry technology along with interest due to the COVID-19 pandemic, presenting a new paradigm in the content market such as entertainment, media, performances, and exhibitions. However, it can be seen that in order for realistic content to have sustained public interest, it is necessary to study storytelling method that can increase immersion in content rather than technological freshness. Therefore, in this study, we propose a immersive content storytelling method using artificial intelligence and photogrammetry technology. The proposed storytelling method is to create a content story through interaction between interactive virtual beings and participants. In this way, participation can increase content immersion. This study is expected to help content creators in the accelerating immersive content market with a storytelling methodology through virtual existence that utilizes artificial intelligence technology proposed to content creators to help in efficient content creation. In addition, I think that it will contribute to the establishment of a immersive content production pipeline using artificial intelligence and photogrammetry technology in content production.

• The Journal of Society for e-Business Studies
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• v.26 no.3
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• pp.119-132
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• 2021

Identification of associated knowledge based on content relevance is a fundamental functionality in managing service and security of core knowledge. This study compares the performance of methods to identify associated knowledge based on content relevance, i.e., the associated document network composition performance of keyword-based and word-embedding approach, to examine which method exhibits superior performance in terms of quantitative and qualitative perspectives. As a result, the keyword-based approach showed superior performance in core document identification and semantic information representation, while the word embedding approach showed superior performance in F1-Score and Accuracy, association intensity representation, and large-volume document processing. This study can be utilized for more realistic associated knowledge service management, reflecting the needs of companies and users.

• Journal of Broadcast Engineering
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• v.28 no.2
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• pp.185-193
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• 2023

As many different over-the-top (OTT) services become ubiquitous, demands for high-quality content are increasing. However, high dynamic range (HDR) contents, which can provide more realistic scenes, are still insufficient. In this regard, we propose a new HDR video reconstruction technique using multi-exposure low dynamic range (LDR) videos. First, we align a reference and its neighboring frames to compensate for motions between them. In the alignment stage, we perform content-based alignment to improve accuracy, and we also present a high-resolution (HR) module to enhance details. Then, we merge the aligned features to generate a final HDR frame. Experimental results demonstrate that our method outperforms existing methods.