• Journal of Broadcast Engineering
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• v.20 no.6
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• pp.807-817
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• 2015

This paper is to propose an encryption method for only an allowed user to see the content for a digital hologram, that is a high value-added content. This paper uses a characteristic of Fresnel transform that the object region is concentrated to a relatively small part of the diffraction plane. By encrypting the concentrated part only the region to be encrypted and in turn the amount of data to be encrypted is reduced a lot, which results in an high efficiency with low encryption rate. As the methodology, a digital hologram is first Fresnel transformed for reconstruction and the result is secondly Fresnel transformed to concentrate the energy into the center of the diffraction plane to encrypt the concentrated region only. For the 2nd transform, energy concentration degree is determined by adjusting the diffraction distance and encryption strength is determined by adjusting the scaling factor. For this we analyze the optimal encryption area according to the diffraction distance and the scaling factor. When applying the proposed method with diffraction distance of 20m the object information was visually unrecognizable with the encryption ratio only 0.005% ~ 0.02%.

• Electronics and Telecommunications Trends
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• v.34 no.4
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• pp.15-22
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• 2019

Recent technological advances in three-dimensional (3D) sensing devices and machine learning such as deep leaning has enabled data-driven 3D applications. Research on artificial intelligence has developed for the past few years and 3D deep learning has been introduced. This is the result of the availability of high-quality big data, increases in computing power, and development of new algorithms; before the introduction of 3D deep leaning, the main targets for deep learning were one-dimensional (1D) audio files and two-dimensional (2D) images. The research field of deep leaning has extended from discriminative models such as classification/segmentation/reconstruction models to generative models such as those including style transfer and generation of non-existing data. Unlike 2D learning, it is not easy to acquire 3D learning data. Although low-cost 3D data acquisition sensors have become increasingly popular owing to advances in 3D vision technology, the generation/acquisition of 3D data is still very difficult. Even if 3D data can be acquired, post-processing remains a significant problem. Moreover, it is not easy to directly apply existing network models such as convolution networks owing to the various ways in which 3D data is represented. In this paper, we summarize technological trends in AI-based 3D content generation.

• KIEAE Journal
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• v.3 no.3
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• pp.59-66
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• 2003

From an sustainable perspective, one unique characteristic of Open Housing is its ability to individualize variable elements (infill) from the permanent elements (support) in accordance with the residents' needs. Such environment-friendly elements of Open Housing can contribute to increasing the life span of the building, reducing the scope of reconstruction, and minimizing the amount of disposed building materials during demolition. The purpose of this research is to analyze the flexibility concept from a typological perspective, so that the concept of open housing can be better understood and its development can be promoted. The main method of this study was content analysis. Based on literature review of flexibility concept in a typological approach, a primary categories were established to describe the flexibility concept such as time for flexibility, scope, and the degree of openness. Subsequently each criterion was elaborated as follows: planning, supply, and utility in the time stage; internal and external flexibility in its scope; and fixed, semi-free, and free flexibility in its openness degree. This research exposes the lack of comprehensive knowledge of Open Housing caused by rather uniform features of previous studies. This research establishes and promotes a systematic approach for a more holistic meaning of Open Housing. This approach should contribute to the proper utilization and further development of sustainable housing.

• Earthquakes and Structures
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• v.13 no.3
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• pp.323-335
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• 2017

A simplified framework for the probabilistic estimation of economic losses induced by the structural vulnerability in single-story and single-bay precast industrial buildings is presented. The simplifications introduced in the framework are oriented to the definition of an expeditious procedure adoptable by government agencies and insurance companies for preliminary risk assessment. The economic losses are evaluated considering seismic hazard, structural response, damage resulting from the structural vulnerability and only structural-vulnerability-induced e]conomic losses, i.e., structural repair or reconstruction costs (stock and flow costs) and content losses induced by structural collapse. The uncertainties associated with each step are accounted for via Monte Carlo simulations. The estimation results in a probabilistic description of the seismic risk of portal-like industrial buildings, expressed in terms of economic losses for each occurrence (i.e., seismic event) that owners (i.e., insured) and stakeholders can use to make risk management decisions. The outcome may also be useful for the definition of the insurance premiums and the evaluation of the risks and costs for the owner corresponding to the insurance industrial costs. A prototype of a precast concrete industrial building located in Mirandola, Italy, hit by the 2012 Emilia earthquake, is used as an example of the application of the procedure.

• Journal of the Korean earth science society
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• v.32 no.5
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• pp.504-513
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• 2011

In this study, we investigated how elementary science teaching has changed with the introduction of the National Assessment of Educational Achievement (NAEA). Teachers are held accountable for student performance as measured by the mandatory nation-wide standards tests to satisfy the needs of accountability and quality assurance systems. In relation to the teaching of science in the elementary school, professionalism meets potential threats with the advent of national test. Through analysis of the classroom teaching and open-ended interviews, we explored the teacher's concerns about the national test and how their science classes have changed to prepare for this test. According to the results, the national test made elementary teachers accountable for the content of their science classes, limits teachers' autonomy in reconstruction of curriculum, and forced teachers to conduct conclusion-centered lessons even in elementary science classes. In addition, teachers argue that the national test precludes the possibility of differentiated education and differentiated assessment. Based on the results, we suggested a new professionalism in this accountability era, so called 'informed professionalism', which refers to the ability of teachers to interpret and implement curriculum and policy mandates at the local, school and classroom level to generate equitable and improved student outcomes through teaching and learning. We also suggested further research on the teacher professionalism in teaching science contents.

• Journal of the Korean Society of Costume
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• v.62 no.8
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• pp.118-133
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• 2012

A historical research on the costume of memorial service officials during the period of late 18th century, King Jeongjo period, is performed for an accurate reconstruction of the memorial service for King Danjong, which is a part of King Danjong Cultural Festival held at Yeongwol. This paper summarizes the results of the research as follows: 1. Jangneung memorial service is held only on Hansik day and the procedure follows the rule based on Gukjooryeui(國朝五禮儀). The service was first held in 1791 for King Danjong and his royal followers. 2. The rule based on Chunkwantonggo(春官通考), defines the king's tomb memorial services and attendees. King Danjong's memorial service follows the rule regarding its attendees and the attendees include high-ranking local government officials, local confucian scholars, and service men. 3. The costume of attendees for the King Danjong's memorial service is as follows: 1)Dangsangkwan(堂上官) and Danghakwan(堂下官) wear Sangbok(常服), which consisted of Samo(紗帽), Heukdanllyeong(黑團領), Pumdae(品帶), and black boots(黑靴). 2)Local confucian scholars wear their uniform consisting of Yukeon(儒巾), Dopo(道袍), Sejodae, and black boots. 3)Service men wear their uniform consisting of Jeonjakeon(典字巾), red-robe with rounded collar called Hongui(紅衣), Kwangdaw hoe(廣多繪), and Uuhae(雲鞋).

• International journal of advanced smart convergence
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• v.12 no.4
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• pp.142-146
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• 2023

We present a method for generating 3D structures and rendering objects by combining VAE (Variational Autoencoder) and GAN (Generative Adversarial Network). This approach focuses on generating and rendering 3D models with improved quality using residual learning as the learning method for the encoder. We deep stack the encoder layers to accurately reflect the features of the image and apply residual blocks to solve the problems of deep layers to improve the encoder performance. This solves the problems of gradient vanishing and exploding, which are problems when constructing a deep neural network, and creates a 3D model of improved quality. To accurately extract image features, we construct deep layers of the encoder model and apply the residual function to learning to model with more detailed information. The generated model has more detailed voxels for more accurate representation, is rendered by adding materials and lighting, and is finally converted into a mesh model. 3D models have excellent visual quality and accuracy, making them useful in various fields such as virtual reality, game development, and metaverse.

• Journal of the Optical Society of Korea
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• v.19 no.1
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• pp.29-37
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• 2015

The wavefront printer records a volume-reflection hologram as a two-dimensional array of elemental holograms from computer-generated holograms (CGHs) displayed on a spatial light modulator (SLM). The wavefront coming from the object is extracted by filtering in the spatial-frequency domain. This paper presents a method to improve color reproduction in a wavefront printer with spatial division of exposures at primary colors, by adaptive partitioning of the SLM in accordance with the color content encoded in the input CGHs, and by the controllable change of exposure times for the recording of primary colors. The method is verified with a color wavefront printer with demagnification of the object beam. The quality of reconstruction achieved by the proposed method proves its efficiency in eliminating the stripe artifacts that are superimposed on reconstructed images in conventional mosaic recording.

• Journal of Microbiology and Biotechnology
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• v.27 no.12
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• pp.2151-2155
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• 2017

Bacteriophages have gained substantial attention as biocontrol and biorecognition agents, substituting antibodies. In this study, a Salmonella Enteritidis-specific bacteriophage, KFS-SE1, was isolated, identified, and characterized. This Siphoviridae phage infects S. Enteritidis with high specificity. This phage is highly stable under various pH (5-11), temperature ($4-60^{\circ}C$), and organic solvent conditions. The KFS-SE1 genome consisted of 59,715 bp with 73 predicted open reading frames and 57.14% GC content; it had a complete set of genes required for phage reconstruction. Comparative phylogenetic analysis of KFS-SE1 revealed that it was very similar to the other Salmonella phages in the Siphoviridae family. These characteristics suggest that KFS-SE1 with its high specificity and host lysis activity toward S. Enteritidis may have various potential applications.

• Journal of information and communication convergence engineering
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• v.11 no.3
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• pp.185-189
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• 2013

A digital hologram generated by a computer calculation (computer-generated hologram or capture using charge-coupled device [CCD] camera) is one of the most expensive types of content, and its usage is expanding. Thus, it is highly necessary to protect the ownership of digital holograms. This paper presents an efficient visual security scheme for holographic image reconstruction with a low scrambling cost. Most recent studies on optical security concentrate their focus on security authentication using optical characteristics. However, in this paper, we propose an efficient scrambling method to protect a digital hologram. Therefore, we introduce in this paper several scrambling attempts in both the spatial domain and frequency domain on the basis of the results of analyzing the properties of the coefficients in each domain. To effectively hide the image information, 1/4, 1/256, and 1/16,384 of the original digital hologram needs to be scrambled for the spatial-domain scheme, Fresnel-domain scheme, and discrete cosine transform-domain scheme, respectively. The encryption schemes and the analyses in this paper can be expected to be useful in the research on encryption and other works on digital holograms.