• 보존과학연구
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• s.26
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• pp.57-75
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• 2005

The burial custom in the Youngsan river area was to build a jar-coffin and lay the body in state, however the methods in building and moulding the massive jar, as well as in which kiln it was made has not been examined precisely. Thus, this research not only investigates previous results related to the manufacturing methods of massive jar-coffins, but also examines samples that were excavated and collected. The clay used to produce jar-coffin consists a large portion of unglazed qualities, which was split-moulded from the bottom up to the mouth area. The interior was finished by applying water, whereas the exterior was decorated by regularly pasting or stamping in parallel with a lattice design. It can be presumed that the finished jar-coffin was not moved, but the ceiling and walls were built around it as a kiln, for the jar-coffin to be oxidized or to reduce the flame condition in a temperature approximately $700~1,200^{\circ}C$The results from the research, however, show limitations to exploit the exact manufacturing method, therefore there is a need for in-depth examinations: mineralogical investigation on a large amount of jar-coffin samples through a polarized light microscope; substance analysis using various equipments; speculation on the temperature in the place of production and the flame inside.

• Journal of the Korea Convergence Society
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• v.7 no.3
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• pp.121-129
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• 2016

This study explains the fundamental problems of MOOC (Massive Open Online Course) based on major survey results for MOOC and online courses conducted in the United States. Consequently, this study integrates the following conclusions and suggestions on how to improve MOOC and convergence of MOOC and universities under the current IT technology. First, the division into small sized classes will solve the problem of massiveness with MOOC. The problem of openness will be solved by providing differentiated courses based on placement tests; and the weakness of onlineness can be complemented through Flipped Learning methodologies. Second, in convergence of universities and MOOC, there are two desirable approache s: credit-free courses use the improved MOOC suggested in this study while credit courses are conducted by Flipped Learning, based on core online courses within departments. In addition, the credit courses offer intensive and supplementary ones together if possible. Third, MOOC will be utilized more widely as it will offer differentiated courses and be produced by education-based universities.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.4
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• pp.335-342
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• 2012

3D point cloud is widely used in Architecture, Civil Engineering, Medical, Computer Graphics, and many other fields. Due to the improvement of 3D laser scanner, a massive 3D point cloud whose gigantic file size is bigger than computer's memory requires efficient preprocessing and visualization. We suggest a data structure to solve the problem; a 3D point cloud is gradually subdivided by arbitrary-sized cube grids structure and corresponding point cloud subsets generated by the center of each grid cell are achieved while preprocessing. A massive 3D point cloud file is tested through two algorithms: QSplat and ours. Our algorithm, grid-based, showed slower speed in preprocessing but performed faster rendering speed comparing to QSplat. Also our algorithm is further designed to editing or segmentation using the original coordinates of 3D point cloud.

• ETRI Journal
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• v.39 no.6
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• pp.820-831
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• 2017

File systems and applications try to implement their own update protocols to guarantee data consistency, which is one of the most crucial aspects of computing systems. However, we found that the storage devices are substantially under-utilized when preserving data consistency because they generate massive storage write traffic with many disk cache flush operations and force-unit-access (FUA) commands. In this paper, we present DJFS (Delta-Journaling File System) that provides both a high level of performance and data consistency for different applications. We made three technical contributions to achieve our goal. First, to remove all storage accesses with disk cache flush operations and FUA commands, DJFS uses small-sized NVRAM for a file system journal. Second, to reduce the access latency and space requirements of NVRAM, DJFS attempts to journal compress the differences in the modified blocks. Finally, to relieve explicit checkpointing overhead, DJFS aggressively reflects the checkpoint transactions to file system area in the unit of the specified region. Our evaluation on TPC-C SQLite benchmark shows that, using our novel optimization schemes, DJFS outperforms Ext4 by up to 64.2 times with only 128 MB of NVRAM.

• Nuclear Engineering and Technology
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• v.51 no.6
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• pp.1589-1595
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• 2019

In this paper, the CLAM steel strengthened by micro-scale Y-Zr-O was prepared by vacuum induction melting followed by electroslag remelting (VIM-ESR). Yttrium (Y) and zirconium (Zr) were easy to aggregates into massive yttrium-zirconium-rich inclusions in the steel melted by vacuum induction melting (VIM), which would interrupt the continuity of the matrix and reduce the mechanical properties of steel. Micron-sized Y-Zr-O inclusions would be produced with the removal of original blocky Y-Zr-rich inclusions and the submicron-sized inclusions smaller than $0.2{\mu}m$ could be retained in the steel. The small grain size and the better refinement and distribution uniformity of Y-Zr-O inclusions after remelting would be responsible for the better yield strength and toughness. For VIM-ESR alloy, the ultimate tensile strength is 749 MPa and the yield strength is 642 MPa at room temperature, meanwhile they are 391 MPa and 367 MPa at $600^{\circ}C$, respectively. Meanwhile, the ductile-brittle transition temperature (DBTT) reduced from $-43^{\circ}C$ (VIM) to $-76^{\circ}C$ (VIM-ESR).

• International journal of advanced smart convergence
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• v.9 no.3
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• pp.105-117
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• 2020

The "New Korean Wave" (Shin Hallyu) phenomenon, which is represented by the global popularity of BTS and director Bong Joon-ho's film "Parasite," is making the world excited. The influence of the Korean Wave is not only on politics, society, and culture, but it also has considerable economic ripple effects. We applied individual in-depth interviews with seven media and marketing experts in China to assess the changes in the impact of Korean cultural content (i.e., Hallyu content) and examine the possibility of marketing for Korean small and medium-sized enterprises (SMEs) products using Hallyu content. Considering its massive market potential, China is still an attractive target for Korean companies and is of even greater importance to SMEs, which are highly dependent on exports and lacking marketing budgets as well as a professional workforce. Korean businesses and the economy at large would get a real boost if they could penetrate the Chinese market by utilizing the strength of Hallyu content. Based on the results of the in-depth interviews, the conclusion of our study suggests the direction of advertising strategy on how Korean products can attract the minds of Chinese consumers by utilizing the Shin Hallyu. This research is a practical study that diagnoses the reality of the Korean Wave in China objectively and has excellent practical implications as it proposes methods of how SMEs should use Hallyu for their marketing strategies.

• Journal of Veterinary Clinics
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• v.33 no.3
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• pp.183-186
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• 2016

An 8-year-old, female lionhead rabbit with clinical sign of hematuria and vaginal discharge with/without blood was submitted to a local animal hospital. On exploratory laparotomy, three round to oval masses were observed in both uterine horns. The lumen of uterus was severely obstructed and distorted because of massive neoplastic proliferation. Histopathologically, the uterine masses revealed papillary projections along with irregular glandular structures into the lumen. The neoplastic foci were composed of numerous irregular sized neoplastic glands originated from uterine glands. These neoplastic cells showed very strong invasive tendency to muscle layer, therefore emboli of neoplastic cells were located in lymphatics. According to immunohistochemistry, the tumor cells in uterine masses demonstrated strong positive signals for cytokeratin, but negative for vimentin. Based on the gross, histopathologic and immunohistochemical features, this case was diagnosed as uterine adenocarcinoma in lionhead rabbit.

• Proceedings of the Korea Multimedia Society Conference
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• 2000.04a
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• pp.328-331
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• 2000

In this paper , we propose a texture feature extraction method of reduce the massive computational time on extracting texture, features of large sized medical such as MRI, CT-scan , and an index structure, called GLTFT, to speed up the retrieval performance. For these, the original image is transformed into a compressed image by Wavelet transform , and textural features such as contrast, energy, entropy, and homogeneity of the compressed image is extracted by using GLCM(Gray Level Co-occurrence Metrix) . The proposed index structure is organized by using the textural features. The processing in compressed domain can give the solution of storage space and the reduction of computational time of feature extracting . And , by GLTFT index structure, image retrieval performance can be expected to be improved by reducing the retrieval range . Our experiment on 270 MRIs as image database shows that shows that such expectation can be got.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.72.3-73
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• 2017

The spatial distribution of sub-halos in a large host halo is usually described as isotropic in the ${\Lambda}CDM$ cosmology. Recent observations, however, show that satellite galaxies around massive galaxies are often located within a preferred plane. In order to understand the origin of such planar alignment, we investigate the spatial distribution of sub-halos around their hosts by using the hydrodynamic cosmological simulation, Illustris. In particular, we analyze the systems resembling the Milky Way (MW) and its satellites, i.e. consisting of MW-sized central galaxy and its at least 11 satellites. The result shows that ~10 % of MW-like systems have the anisotropic satellite galaxy distribution at z = 0. The satellites that are accreted more recently tend to form a flattened structure more frequently, indicating a link of satellite distribution to the surrounding environment. We discuss the physical origin of the anisotropic satellite distribution from the viewpoint of the ${\Lambda}CDM$ paradigm.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1065-1068
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• 2008

Concrete is still one most common construction materials even in railway structures. As structures become massive and mega-sized, the importance of early age concrete quality control becomes more significant. Among various factors, relative humidity and temperature are the primary factors governing the early age quality. Temperature raise due to cement hydration causes stress, which can develop to cracking with internal and/or external restraints. Exposure conditions including ambient temperature, humidity and wind also significantly affect the cracking behavior of early age concrete. Among many of studies on the early age concrete behavior, investigation on the variation of temperature and relative humidity internal of concrete is not common. That is in part because the difficulties in measuring the relative humidity and temperature inside the concrete. This study used a digital sensor with an appropriate logger to measure internal temperature and relative humidity. This direct measuring method is expected to provide more reliable and comprehensive data acquisition on the early age behavior of concrete.