• The Korean Journal of Archival Studies
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• no.36
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• pp.121-152
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• 2013

History education is of growing significance in relation with minority group's identity issue in an irreversible trend of globalization. Archives and the cultural institution can be a major player in the reforming the history education as conducted in Britain. This paper deals with the Moving Here project led by The National Archives. The vision of the project is to overcome barriers to the direct involvement of minority ethnic groups in recording their own history of migration and to ensure this history is passed on to the next generation through schools. More than 200,000 digitised images and documents in the Moving Here have been selected from the 28 content partners' collections. In addition, TNA and the regional partners worked with minority ethnic groups to record their culture and stories. In doing so, real and lasting relation between the community and the ethnic groups has developed. The outputs of the project such as films and stories were distributed free for regional schools. The School section of the Moving Here provides a range of education resources. One of the most impressive outcome of the project is the minority's desire to have their own archives for identity and self-esteem.

• Tunnel and Underground Space
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• v.30 no.6
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• pp.509-518
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• 2020

This study constructed a new simulation platform, including mesh generation process, numerical simulation, and post-processing for results analysis based on exploration data to perform real-scale numerical analysis considering the actual geological structure efficiently. To build the simulation platform, we applied for open-source programs. The source code is open to be available for code modification according to the researcher's needs and compatibility with various numerical simulation programs. First, a three-dimensional model(3D) is acquired based on the exploration data obtained using a drone. Then, the domain's mesh density was adjusted to an interpretable level using Blender, the free and open-source 3D creation suite. The next step is to create a 3D numerical model by creating a tetrahedral volume mesh inside the domain using Gmsh, a finite element mesh generation program. To use the mesh information obtained through Gmsh in a numerical simulation program, a converting process to conform to the program's mesh creation protocol is required. We applied a Python code for the procedure. After we completed the stability analysis, we have created various visualization of the study using ParaView, another open-source visualization and data analysis program. We successfully performed a preliminary stability analysis on the full-scale Dokdo model based on drone-acquired data to confirm the usefulness of the proposed platform. The proposed simulation platform in this study can be of various analysis processes in future research.

• Conservation Science in Museum
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• v.26
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• pp.143-160
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• 2021

The Seoul Baekje Museum has been conducting excavations at the Ancient Tomb Complex in Seokchon-dong, Seoul (Historic Site No. 243), known to be tombs of the royal family and the ruling class during the Hanseong period of the Baekje Kingdom. In this study, gold earrings that were revealed during the excavation underwent scientific analysis and conservation treatment. Stereo microscopy, SEM, X-ray imaging, CT, and XRF were applied in the analysis, and the characteristics, internal structure, and composition of the earrings as well as their production method were investigated. The results confirmed that the main hoops of the gilt-bronze earrings were made of copper cores gilt using mercury amalgamation. The findings also revealed that the hexahedron in the middle pendant was made by connecting small rings using molten gold powder, and the pendant sphere at the end was formed by soldering two hemispheres. As for the two thin-hoop earrings, they showed similar surface compositions but were made using different methods, with one made from a copper core wrapped with a gold plate and the other made by bending a gold rod. The gold content varied depending on the item and the place of measurement, but overall the earrings showed a relatively high gold content of approximately 19 to 21K. The purity of the golden earrings and the sophisticated manufacturing techniques applied indicate the high status of the buried person and of the tomb complex in Seokchong-dong.

• Journal of the Korean Geotechnical Society
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• v.25 no.12
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• pp.57-67
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• 2009

Along with the advanced construction technologies, the maximum size of coarse aggregate used for dam construction ranges from several cm to 1m. Testing the original gradation samples is not only expensive but also causes many technical difficulties. Generally, indoor tests are performed on the samples with the parallel grading method after which the results are applied to the design and interpretation of the actual geotechnical structure. In order to anticipate the exact behavior characteristics for the geotechnical structure, it is necessary to understand the changes in the shear behavior. In this study, the Large Triaxial Test was performed on the parallel grading method samples that were restructured with river bed sand-gravel, with a different maximum size, which is the material that was used to construct Dam B in Korea. And the Stress - Strain characteristics of the parallel grading method samples and the characteristics of the shear strength were compared and analyzed. In the test results, the coarse-grained showed strain softening and expansion behavior of the volume, which became more obvious as the maximum size increased. The internal angle of friction and the shear strength appeared to increase as the maximum size of the parallel grading method sample increased.

• Journal of Life Science
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• v.33 no.4
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• pp.371-381
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• 2023

Endocrine disrupting chemicals (EDCs), used in a variety of products in modern society, are hormone-like substances that cause various diseases. Humans are exposed to EDCs through their inclusion in pesticides, plastics, cosmetics, detergents, and drugs. Bisphenol A (BPA), one of the representative endocrine disruptors, is an estrogen-like substance that has been widely used commercially in plastic and epoxy resins. BPA is a chemical that can disrupt the endocrine system, leading to reduced reproductive function, obesity, cancer, and neurodevelopmental disorders. Since the adverse health effects of BPA began to be reported the use of BPA has been regulated worldwide. Various alternatives to BPA have been widely used worldwide; representatively, bisphenol S (BPS) and bisphenol F (BPF) are the most commonly used in commercial contexts. BPS and BPF may cause endocrine-disrupting effects like those of BPA due to their similar chemical structures. Recent studies have reported that BPS and BPF disrupt the neurodevelopmental process and cause neurodevelopmental disorders. Therefore, future studies will be required for safety verification of BPA alternatives and the development of new alternatives to BPA for brain health. In this review, we reviewed the effects of BPA and the alternatives, BPS and BPF, on the nervous system.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.2
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• pp.97-104
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• 2023

In order to maximize the utilization of recycled fine aggregate, high strength mortar made of 100 % recycled fine aggregate was prepared, and its physical properties were evaluated to determine the possibility of using recycled fine aggregate as structural aggregate. The effect caused by the amount of nanosilica on the physical properties of w/b 0.2 recycled fine aggregate mortar consisting of cement, silica fume, and blast furnace slag. To improve the dispersion of nanosilica inside mortar, an aqueously dispersed nanosilica solution by ultrasonic tip sonication was prepared, and incorporated into the mortar to evaluate changes in mortar flow, porosity and compressive strength depending on nanosilica content. According to the experimental results, mortar flow decreased as the replacement ratio of nano-silica increased. As the replacement ratio of nanosilica increased up to 0.75 %, the porosity decreased and the compressive strength increased, but, at a replacement ratio of 1 %, the porosity increased and the compressive strength decreased. It was confirmed that the nano-silica replacement ratio of 0.75 % was optimum proportion to maximize the mechanical performance of high-strength recycled fine aggregate mortar.

• The Korean Journal of Zoology
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• v.15 no.3
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• pp.111-131
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• 1972

Fine structures of retina of an ommatidium in dragonfly, having eyes of closed rhabdom type, were studied under light and electron microscopes. The ommatidia consisted of eight retinular cells distributed in a circular pattern and the retinular layer in turn can be divided into three sublayers according to the number of cells in the retina. Each retinular cell has different starting points in the retina and the length of retinular cells is varied greatly; the length of one distal retinular cell shows one half of that of others. In the middle layer, three proximal retinular cells interconnect the adjacent two rhabdoms which are triangular in the appearence of the cross section which in turn consisted of tubular, parallel and lamellated microvilli. The rhabdom is formed by three rhabdomeres, each of which is separated by $120^{\circ}$ between them, but they can be distinguished into two parts according to electron density. Around the outer part of microvilli composing rhabdom, electron density was much less than the inner part of the structure. The microvilli of the inner part appear to be connected to the cytoplasm of retinular cells. Rough endoplsmic reticulum with enlarged cisternae runs through the vacuoles in the outer part of distal retinular cells. Abundant mitochondria concentrated in the vicinity of rhabdom are found at the central part of the retinular cells, while in the area of immediate vicinity of the rhabdom, prominent vacuoles are observed. Above the rhabdom of an ommtidium stands a crystalline cone which is consisted of four cone cells arranged radially along the axis. The crystalline cone is surrounded by cells containing pigment granules. The outermost photoreceptor element of an ommatidium is corneal lens.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.127-128
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• 2021

This study suggests surface wave communication, which uses a metal surface as a medium, to provide wireless communication in the extreme environment due to surrounding metal materials on vessels. The test was conducted on a G/T 265 tons tug boat, and to confirm the possibility of surface wave communication between a bridge and each designated space in the boat. As a result, the transmission speed was 13Mbps in average. For the test case between the bridge and the engine room, transmission speed was 4.3Mbps while the engine was on, and 1.2Mbps during sailing. It was able to be overcome by partially changing the equipment installation location. Surface wave communication in a bow storage, a fully enclosed space, had 8Mbps better transmission speed than wireless communication; this confirmed the superiority of surface wave communication in confined spaces on a vessel. Additional surface wave generators were designed and applied to resolve the paint issue. It is expected to apply surface wave communication to implement the new wireless solution on vessels.

• Journal of the Korea Concrete Institute
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• v.26 no.4
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• pp.441-448
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• 2014

From several researches, recently, it was found that using hollowed precast concrete (HPC) column made more compact concrete casting in joint region possible than using normal solid PC (Precast concrete) column. Therefore, the rigidity of joints can be improved like those of monolithic reinforced concrete (RC). After filling the hollow with grout concrete, however, it is expected that the HPC column behaviors like composite structure since PC element and grout concrete have different materials as well as there is a contact surface between two elements. These may affect the structural behavior and strength of the composite column. A compressive strength test was performed for the HPC column with parameter of hollow ratio for the case with and without grout in the hollow and the result is presented in this paper. The hollow ratios in the test are 35, 50 and 59% of whole section of column. Concentrated axial force was applied to top of the specimens supported as pin connection for both ends. In addition, finite element (FE) analysis was performed to simulate the failure behavior of HPC column for axial compression. As a result, it was found that the hollow ratio did not affect the initial stiffness of HPC filled with grout regardless of the strength difference of HPC and grout. However the strength was increased inversely corresponding to the hollow ratio. The structural capacity of HPC without grout closely related to the hollow size. Especially, the local collapse governs the overall failure when the thickness of HPC is too thin. Based on these effect, a suitable equation was suggested for calculation of the compressive strength of HPC column with or without grout. FE analysis considering the contact surface between HPC and grout produced a good result matched to the test result.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.3
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• pp.253-261
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• 2005

Catalytic wet oxidation of ppm levels of trichloroethylene (TCE) in water has been conducted using $TiO_2$-supported cobalt oxides at a given temperature and weight hourly space velocity. 5% $CoO_x/TiO_2$ might be the most promising catalyst for the wet oxidation at $36^{\circ}C$ although it exhibited a transient behavior in time on-stream activity. Not only could the bare support be inactive for the wet decomposition reaction, but no TCE removal also occurred by the process of adsorption on $TiO_2$ surface. The catalytic activity was independent of all particle sizes used, thereby representing no mass transfer limitation in intraparticle diffusion. Characterization of the $CoO_x$ catalyst by acquiring XPS spectra of both fresh and used Co surfaces gave different surface spectral features of each $CoO_x$. Co $2p_{3/2}$ binding energy of Co species exposed predominantly onto the outermost surface of the fresh catalyst appeared at 781.3 eV, which is very similar to the chemical states of $CoTiO_x$ such as $Co_2TiO_4$ and $CoTiO_3$. The spent catalyst possessed a 780.3 eV main peak with a satellite structure at 795.8 eV. Based on XPS spectra of reference Co compound, the TCE-exposed Co surfaces could be assigned to be in the form of mainly $Co_3O_4$. XRD measurements indicated that the phase structure of Co species in 5% $CoO_x/TiO_2$ catalyst even before reaction is quite comparable to the diffraction lines of external $Co_3O_4$ standard. A model structure of $CoO_x$ present on titania surfaces would be $Co_3O_4$, encapsulated in thin-film $CoTiO_x$ species consisting of $Co_2TiO_4$ and $CoTiO_3$, which may be active for the decomposition of TCE in a flow of water.