• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.9
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• pp.623-627
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• 1999

We report a new in-situ fluorine passivation method without in implantation by employing excimer laser annealing of $SiO_{x}F_{y}$/a-Si structure and its effects on p-channel poly-Si TFTs. The proposed method doesn't require any additional annealing step and is a low temperature process because fluorine passivation is simultaneous with excimer-laser-induced crystallization. A in-situ fluorine passivation by the proposed method was verified form XPS analysis and conductivity measurement. From experimental results, it has been shown that the proposed method is effective to improve the electrical characteristics, specially field-effect mobility, and the electrical stability of p-channel poly-Si TFTs. The improvement id due to fluorine passivation, which reduces the trap state density and forms the strong Si-F bonds in poly-Si channel and $SiO_2/poly-Si$ interface. From these results, the high performance poly-Si TFTs canbe obtained by employing the excimer-laser-induced fluorine passivation method.

• Journal of the Korean Society for Railway
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• v.12 no.4
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• pp.526-534
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• 2009

PRT(Personal Rapid Transit) can be described as a system of driverless taxicabs, that. automatically take passengers to their destinations along dedicated guideways, without intermediate stops.It is ideally suited as a short feeder transportation for on-demand circulation operations at train stations, airports, office complex, amusement park and shopping center. This PRT study do suggest that a PRT system could provide a high level of mobility to the commuters making work trips, workers making work, shopping and other non-work trips, residents making shopping and other non-work trips and recreational riders.This study presents the possibilities of PRT applications in national level. As the technology continues to advance, there may be opportunities to improve the reliability, and efficiency of our future public transportation systems.

• Journal of Adhesion and Interface
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• v.16 no.2
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• pp.55-62
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• 2015

It was investigated that the effect of surface modification and concentration of fumed silica on the adhesion properties and thermal stability of 2-EHA/AA pressure sensitive adhesive (PSAs) prepared by UV irradiation. The influence of repeating units of crosslinking agent on PSAs were also studied. From SEM analysis, PSAs synthesized with surface modified silica had finer dispersion of silica particles in polymer matrix due to the interfacial interaction. Results of the study showed that increase in tack and peel strength when under 0.3 wt% of silane treated silica were added in the reaction mixture. The addition of PEGDMA for crosslinking agent offers positive effect on adhesion properties in comparison with PSAs using EGDMA for crosslinker, which may be attributed to high mobility of ethylene oxide repeating units in PEGDMA. From the thermal degradation residue of PSAs, it was revealed that thermal stability was improved with silica addition due to the strong interfacial bonding between silane modified silica and polymer matrix, which may act as a thermal barriers into 2-EHA/AA PSAs.

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.2955-2962
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• 2014

Asian ginseng is used as a treatment for cardiovascular diseases, ischemia, and cancers. High mobility group box 1 (HMGB1) protein acts as a late mediator of severe vascular inflammatory conditions. However, the effect of ginsenosides from Asian ginseng on HMGB1-induced inflammatory responses has not been studied. We addressed this question by monitoring the effects of ginsenoside treatment on lipopolysaccharide (LPS) and cecal ligation and puncture (CLP)-mediated release of HMGB1, and HMGB1-mediated regulation of proinflammatory responses. Ginsenoside treatment suppressed LPS-mediated release of HMGB1 and HMGB1-mediated cytoskeletal rearrangements. Ginsenosides also inhibited HMGB1-mediated inflammatory responses. In addition, ginsenosides inhibited the production of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and activation of protein kinase B (Akt), nuclear factor-${\kappa}B$ (NF-${\kappa}B$), and extracellular-regulated kinases (ERK) 1/2 by HMGB1. Ginsenosides also decreased CLP-induced release of HMGB1, production of interleukin (IL) $1{\beta}/6$, and mortality. These results suggested that ginsenosides may be potential therapeutic agents for treatment of vascular inflammatory diseases through inhibition of the HMGB1 signaling pathway.

• Clean Technology
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• v.17 no.4
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• pp.363-369
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• 2011

To evaluate the feasibility of electrodialysis for ammonia nitrogen removal from wastewater, the effects of operating parameters such as diluate concentration, applied voltage and flow rate on the removal of ammonia nitrogen were experimentally estimated. The removal rate was evaluated by measuring the elapsed time for ammonia nitrogen concentration of diluate to reach 20 mg/L. Limiting current density (LCD) linearly increased with ammonia nitrogen concentration and flow rate. The elapsed time was linearly proportional to initial concentration of diluate. Due to relatively large equivalent ion conductivity and ion mobility of ammonia nitrogen, the removal rate increased consistently with flow rate. Increase in the applied voltage gave positive effect to removal rate. From the operation of the electrodialysis module used in this research, the flow rate of 3.2 L/min and 80~90% of applied voltage for LCD are recommended as the optimum operating condition for the removal from high concentrate ammonia nitrogen solution.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.6
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• pp.477-481
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• 2014

Flexible electronics have been to the fore because it is believed that flexibility can add incredible value such as light weight and mobility into the existing electronic devices and create new markets of large-area and low-cost electronics such as wearable eletronics in near future. Offset printing processes are regarded as major candidates for manufacturing the flexible electronics because they can provide the patterning resolution of micron-size effectively in large-area. In view of mechanics, the most important viewpoint in offset printing is how to achieve the synchronized movement of two contact surfaces in order to prevent slip between two contact surfaces and distortion of the blanket surface during ink transfer so that the high-resolution and good-overlay patterns can be printed. In this paper, a novel low-cost measurement method of the synchronization error using the motor control output signals is proposed and the compensation method is presented to minimize the synchronization error.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.5
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• pp.935-941
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• 2009

In this paper, we study the communication based train control technology which has been improved for the railroad operation efficiency. All the signalling systems currently used in Korea are track circuit based train control systems, which train mobility and safety are considered on. When it comes to the recent abroad trend, development for communication based train control system, which arises new paradigm in the field of high density train separation, have been promoted. Considering the urgent necessity to develop the above mentioned technology, we would like to propose the research and development of communication based train control system and the present domestic and foreign statuses of on-board equipment development. In this paper, therefore, we had been developed localization on-board equipment of communication based train control system, which is the key construction of train control systems. For its verification, we accomplished installation and yard test on-board equipment of communication based train control system on Bundang-line's EMU(Electrical Multiple Unit).

• Food Science and Preservation
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• v.19 no.2
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• pp.287-293
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• 2012

Lycopene, found in tomatoes and tomato products, has antioxidant, anticancer, and anti-inflammatory effects. High-mobility-group box 1 (HMGB1) mediates the pro-inflammatory responses in several inflammatory diseases. In this study, the potential roles of lycopene in the HMGB1-mediated pro-inflammatory gene expressions in the primary human-umbilical-vein endothelial cells (HUVECs) were investigated. The data showed that HMGB1 upregulated the expressions of monocyte chemotactic protein 1 (MCP-1), interleukin-6 (IL-6), secretory phospholipase A2 (sPLA2)-IIA, and prostaglandin E2 (PGE2). Lycopene pre-incubation for 6 h decreased the HMGB1-mediated induction of MCP-1, IL-6, sPLA2-IIA, and PGE2. Further study revealed that the inhibitory effects of lycopene on the HMGB-1 induced expression of pro-inflammatory genes were mediated by the inhibition of two important inflammatory cytokines: tumor necrosis factor (TNF)-${\alpha}$ and nuclear factor (NF)-${\kappa}B$. These results suggest that HMGB1 upregulated the expression of pro-inflammatory genes and lycopene inhibited HMGB-1-induced pro-inflammatory genes by inhibiting TNF-${\alpha}$ and NF-${\kappa}B$. This finding will serve as an important evidence in the development of a new medicine for the treatment of inflammatory diseases.

• Proceedings of the Korea Crystallographic Association Conference
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• 2003.05a
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• pp.8-8
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• 2003

Electron-phonon interaction plays a significant role in forming of colossal magnetoresistance effect (CMR). Polaron formation was observed by neutron diffraction and by extended X-ray absorption fine structure (EXAFS) analysis. Local probe as given by the EXAFS is a useful method to study the polaronic charge and its dependence on temperature and ions size. Here we present the EXAFS study of polaronic charge in La/sub 0.7/Ca/sub 0.3-X/Ba/sub X/MnO₃ compositions. The single phase La/sub 0.7/Ca/sub 0.3-X/Ba/sub X/MnO₃ manganites (x=0; 0.03; 0.06, ..., 0.3) were prepared by ceramic technology [1]. The Curie temperature was determined by extrapolation of the temperature dependence of the magnetization (down to zero magnetization). EXAFS experiments were carried out at the 7C EC beam line of the Pohang Light Source (PLS) in Korea. The atomic pair distribution functions (PDF) were obtained by re-regularization method [2] from filtered spectra. The PDF for the x=0.3 sample showed a single peak function and for x=0.0, 0.03, 0.06, 0.09, 0.12 compositions were asymmetric in agreement with a small Jahn-Teller elongation of two (short and long) bonds of the MnO/sub 6/ octahedron. Dispersion, σ/sub Min-O//sup 2/, and asymmetry, σ/sub Min-O//sup 3/, of the Mn-O bond distances varied significantly with x and showed a maximums at x=0.09. The maximum of σ/sub Min-O//sup 2/ is caused by increase of dynamic rms displacements of the Mn-O distances near the T/sub C/. The observed x dependence of σ/sub Min-O//sup 3/ reflects the reduction of charge carriers mobility at approaching to T/sub C/ from low as well as high temperatures.

• Korean Journal of Crystallography
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• v.1 no.1
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• pp.19-28
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• 1990

6H-SiC is a promising material (Eg=3.0eV) for blue light-emitting doide and high-temperature semiconducting device. In the experiment, single crystals of a-SiC have been grown by the sublimation method to fabricate blue light~emitting diode. During the growth of a-SiC single crystals, a temperature Vadient, yonh temperature and pressure ranges were kept 44℃/cm , 1800-1990℃ and 50-1000 mTorr, respectively. Single crystals obtained in Acheson furnace were used as seed crystals. Polarizing microscopy and back-reflection X-ray Laue diffraction showed that the a-SiC crystal was epitaxially and on the seed crytal. It was found by XRD analysis that when other growth conditions were the same, a-SiC was grown at the temperature above 1840℃ and 3C-SiC was gown at lower temperature or under low supersaturation of vapor. The carrier type. concentration and mobility were measured be hole(p-type), 7.6x1014cm-3 and 19cm2V-1sec-1, respectively, by van der Pauw method.