• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.875-876
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• 2006

Superconducting fault currents(SFCLs) are expected to improve not only reliability but also stability of power systems. The analysis on current limiting operations of the flux-lock type SFCL, which consists of a flux-lock reactor wound an iron core and a YBCO thin film, was compared the open-loop with the closed-loop iron core of the subtractive polarity winding. In the SFCL, operation characteristics could be controlled by adjusting the inductances and the winding directions of the coils, then magnetic field induced in the iron core. The current limiting characteristics under the same experimental conditions were generated regardless of the iron core conditions. We confirmed that capacity of the SFCL was increased effectively by the closed-loop iron core. However, the power burden of the system could be lowered by the open-loop iron core.

• IMMUNE NETWORK
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• v.6 no.1
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• pp.20-26
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• 2006

Background: Rheumatoid arthritis (RA) is a chronic and systemic inflammatory disease that is characterized by invasive synovial hyperplasia, leading to progressive joint destruction. Recent studies have described that RA is caused by virus, bacteria or outside material. Approximately 2 to 20% of RA cases arc reported to be associated with infected hepatitis C virus (HCV). However, the mechanisms underlying virus-induced RA are still unknown. Moreover, few molecular studies have addressed the inflammatory aspects of HCV-associated autoimmune RA. In this study, we aimed to determine whe ther or not another HCV core protein transactivates the IL-8 gene expression, prototypic chemokine, in synovial cell. Methods: To establish the HCV core expressing stable synovial cell line, pCI-neo-core, a plasmid encoding HCV core protein, were transfected to HIG-82 cell line that is an established cell line from rabbit periaricular soft tissue. We examined the morphological changes and cell cycle distribution of HIG-82 cells with expression of HCV core protein by inverted microscopy and flow cytometry analysis, respectively. Also, we determined the mRNA levels of Interleukin (IL)-6 and IL-8 related to the inflammation by RT-PCR and then analyzed regulation of IL-8 expression by the NF-${\kappa}B$ pathway. Results: Our study showed no significant differences in morphology and cell cycle between HIG-82 control cell line and HIG-82 expressing HCV core protein. However, expression of HCV core protein induces the IL-8 mRNA expression in HIG-82 core cells via activated NF-${\kappa}B$ pathway. Conclusion: These results suggest that HCV core protein can lead to enhanced IL-8 expression. Such a proinflammatory role may contribute to the etiologic pathogenesis in RA patients with HCV infection.

• BMB Reports
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• v.41 no.10
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• pp.733-738
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• 2008

Although previous studies have implicated a role for TC1 (C8orf4) in cancer cell proliferation, the molecular mechanism of its action is still largely unclear. In this study, we showed, for the first time, that the mRNA levels of TC1 were upregulated by mitogens (FBS/thrombin) and at least partially, through the ERK1/2 signaling pathway. Interestingly, the over-expression of TC1 promoted the $G_1$- to S-phase transition of the cell cycle, which was delayed by the deficiency of ERK1/2 signaling in fibroblast cells. Furthermore, the luciferase reporter assay indicated that the over-expression of TC1 significantly increased Cyclin D1 promoter-driven luciferase activity. Taken together, our findings revealed that TC1 was involved in the mitogen-activated ERK1/2 signaling pathway and positively regulated $G_1$- to S-phase transition of the cell cycle. Our results may provide a novel mechanism of the role of TC1 in the regulation of cell proliferation.

• Journal of the Korean Society for Heat Treatment
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• v.16 no.4
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• pp.197-204
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• 2003

Honeycomb structure has been fabricated by brazing method using 0.1 wt%C and 1.0wt%C carbon steel core and STS304 stainless steel face sheet. Core shear strength ratio in W and L directions was 1:1.03 in 7 mm cell size, whereas 1:1.45 in 4 mm cell size. Flexural strength on face sheet was 166.4 MPa (0.1 wt%C, W direction), 171.1 MPa (0.1 wt%C, L direction), and 120.2 MPa (1.0 wt%C, W direction) in 7 mm cell size. And in 4mm cell size specimen, it was 169.2 MPa (0.1 wt%C, W direction), 224.2 MPa (0.1 wt%C, L direction). This means that flexural strength of 0.1 wt%C core material was higher than that of 1.0wt%C core material, which was contrary to expectation. SEM and EDS analysis represented that grain boundary diffusion had occurred in0.1 wt%C core, but no grain boundary diffusion in 1.0 wt%C core. And corrugated surface of 0.1 wt%C core was flat, whereas that of 1.0 wt%C core was not flat. As a result, contact area between two 1.0 wt%C cores was much less than that of 0.1 wt% cores, It is thought to be main reason for lower flexural strength of 1.0 wt%C core.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.25-26
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• 2023

The internal core material and external color of a sandwich panel have a significant impact on the performance of the sandwich panel. For use on roofs and walls, the internal core material and external color must be considered. Therefore, the surface and back side temperatures were measured for each exterior color and inner core material type. For the internal core materials, urethane foam and Expanded Poly Styrene(EPS), which are core materials mainly used in sandwich panels, were selected. As colors, black and ivory were selected according to brightness, and a total of five colors were selected: red, blue, and green, which are the three primary colors of light. As a result, there were differences in surface and temperature depending on the external color and type of internal core material. Regardless of the color, the temperature was measured lower for panels with urethane foam than for panels with an internal core of EPS. This is believed to have been influenced by the difference in thermal conductivity of urethane foam being 0.023W/(m·K) and that of EPS being 0.032W/(m·K). In addition, panels with a black exterior color were found to have higher surface and back temperatures than panels of other colors, and ivory-colored panels had lower back temperatures regardless of the core material. This is proportional to the brightness and light-absorbing characteristics.

• Nuclear Engineering and Technology
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• v.29 no.5
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• pp.399-405
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• 1997

In this study a new phase separated spectral analysis algorithm is proposed to identify CSB vibration mode directly from ex-core neutron signals. Ex-core neutron signals can be decomposed into the global, core support barrel (CSB) beam mode, and CSB shell mode components by the new phase separation algorithm based on the characteristics of Fourier transform. By using the proposed algorithm and the conventional spectral analysis the vibration mode of the CSB and the fuel assembly of Ulchin-1 NPP were identified from measured ex-core neutron signals.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1604-1606
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• 2003

In this paper, investigated the core of transformer of high power factor and high effectiveness about design and choice technology. Transformer that use existent general core and material is high no-load loss power. Presented core choice method that can reduce loss. Could do to reduce loss according to choice technology of use material more than about 10 (%). Presented classification and check list by Core's type.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.395-398
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• 1995

For the core loss measurement under arbitrary waveform of magnetic induction, we have constructed a single sheet core loss measuring system which consists of yoke apparatus for single sheet of $10\;cm{\times}10\;cm$, arvitrary waveform synthesizer, B-feedback system, and two channel transient recorder. Using the constructed measuring system, we can measure core loss including higher harmonics up to 2 kHz. Core loss of non-oreinted electrical steel was increased exponentially when higher harmonic frequency was increased or amplitude of harmonic induction was increased.

• Journal of the Korea Institute of Building Construction
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• v.24 no.4
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• pp.437-445
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• 2024

This study investigated the thermal insulation performance of Azon and Azo-Core, two materials commonly used in window frames, for potential application in window shutters. A three-pronged evaluation approach was employed, utilizing the Therm 7.4 software, confidential test results, and dedicated thermal insulation testing. The simulation data indicated that both Azon and Azo-Core offered superior insulating properties compared to conventional shutter insulation materials. When incorporated into shutters, these materials achieved a first-grade sealing performance and a measured average thermal conductivity of 2.018W/m²·K. While this thermal conductivity value surpasses the standard requirements of 1.5W/m²·K for central regions and 1.8W/m²·K for southern regions in Korea, it falls within the acceptable limit of 2.2W/m²·K established for the Jeju region. Based on these findings, Azo-Core, warranting further dedicated research, presents itself as a promising candidate for shutter insulation material, particularly in applications targeting the Jeju region.

• Journal of Adhesion and Interface
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• v.11 no.3
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• pp.112-119
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• 2010

Poly(methyl methacrylate)/poly(butyl acrylate) PMMA/PBA core-shell composite particles were prepared by the emulsion polymerization of MMA and BA in the presence of different concentration of sodium dodecyl benzene sulfonate (SDBS). The following conclusions are drawn from the measured conversion and particle size distribution, morphology, average molecular weight distribution, observation of film formation and particle formation, glass transition temperature and physical properties of polymerized core-shell composition particles for using adhesive binder. When the concentration of 0.03 wt% surfactant, the conversions of PMMA and PBA core polymerization are excellent as 95.8% for PMMA core and 92.3% for PBA core. Core-shell composite particles are obtained 90.0% for PMMA/PBA core-shell composite particles and 89.0% for PMMA/PBA core-shell composite particles. It is considered that the core and shell particles are polymerized to be confirmed FT-IR spectra and average molecular weight measured with a GPC, formation of the composite particles is confirmed by the film formation from normal temperature, and composition of inside and outside of the composite particle is confirmed by TEM photograph. The synthesized polymer has two glass transition temperatures, suggesting that the polymer is composed of core polymer and shell polymer unlike general copolymers. It is considered that each core-shell composite particle can be used as a high functionality adhesion binder by the measurement of tensile strength and elongation.