• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.3
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• pp.75-82
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• 2004

The allowable exhaust standard has been intensified as a part of the countermeasure to decrease air pollution in the world. As the cars with an alternative fuel starts to get into the spotlight, the cars with low emission has been introduced and exhaust gas regulation forced in this country. These days, LPG vehicles, which infrastructure of fuel was already built up, and CNG vehicles are recognized for alternative fuel cars in this country. In this study, the constant volume combustion chamber was manufactured and used for experiments to obtain the ignition characteristics of LPG fuel and the optimal ignition energy. The experiment measured the combustion characteristics, in regard to the change of combustion variable, and the change of ignition energy. During the combustion of fuel, the maximum temperature inside the combustion chamber is higher when the initial pressure is higher. The burning velocity also seems to have the same characteristic as the temperature. However, the heat flux did not change much with the theoretical correct mixture but the various initial temperature of the combustion chamber. The heat flux got faster and ignition energy bigger as the dwell time of the ignition system expanded. When the dwell time get longer, the ignition energy also increased then fixed. The ignition energy increased as the initial pressure inside the combustion chamber higher. The heat flux got faster as the dwell time expanded.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.2
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• pp.197-204
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• 2014

As more and more renewable energy resources are connected into the existing power system and their generation capacities are increasing, the need for regulations to minimize their impacts on the power grid is increasingly growing. And minimizing the irregular impacts made by grid-connected wind generators is important, since the output power generated by renewable energy resources can be changed easily by the weather condition and surrounding environment. In South Korea, an operational technical standard for distributed generation is used as a regulation, in which renewable energy sources including wind power are considered as a kind of distributed generation. In this paper, an international standard, IEC 61400-21, for the grid-connected wind turbine generating system(WTGS) will be introduced and a comprehensive and detailed review on the measuring methods of power quality characteristic parameters for WTGS based on the related IEC standards will be presented. Additionally, some prerequisites for applying the international standards to KEPCO system will be proposed.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.2
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• pp.78-83
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• 2011

Diesel engine has many advantages such as high thermal efficiency, low fuel consumption and low emission of CO2. However, the diesel engine faced with strengthened emission regulation about NOx and PM. To suppress NOx emission, after-treatment systems such as Lean NOx Trap (LNT), Selective Catalytic Reduction (SCR) are considered as a more practical strategy. This paper investigated the performance of Lean NOx trap of the 4 stroke diesel engine which had a LNT catalyst. Characteristic of exhaust emission at NEDC mode was analyzed. From this result, the effect of nozzle attaching degree, injection quantity and gas flow change on NOx conversion performance was clarified.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.23
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• pp.10495-10500
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• 2015

Background: To evaluate the effects of bufalin in A549 human lung adenocarcinoma epithelial cells in vitro and assess the underlying mechanisms. Materials and Methods: Human A549 non-small cell lung cancer (NSCLC) cells were treated with various concentrations of bufalin. Cell proliferation was measured by CCK-8 assay, apoptotic cell percentage was calculated by flow cytometry and morphological change was observed by inverted phase contrast microscopy/transmission electron microscopy. In addition, the membrane potential of mitochondria was detected by JC-1 fluorescence microscopy assay, and the related protein expression of cytochrome C and caspase-3 was analyzed by Western blotting. Results: Bufalin could inhibit the proliferation of A549 cells via induction of apoptosis, with the evidence of characteristic morphological changes in the nucleus and mitochondria. Furthermore, bufalin decreased the mitochondrial membrane potential with up-regulation of cytochrome C in the cytosol, and activation of caspase-3. Conclusions: Bufalin inhibits the proliferation of A549 cells and triggers mitochondria-dependent apoptosis, pointing to therapeutic application for NSCLC.

• Journal of the Korea Safety Management & Science
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• v.10 no.3
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• pp.35-41
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• 2008

It is a fact that domestic performance art has been sharply progressed but it is focused on only performance quality technique, not on safety of performers and the audience. It is a pity that people's effort to keep safe stage environment have not traced to innovative change, eventually leading to be forced to perform under hazardous condition. This study is to find out and identify that domestic regulation and accident cases are investigated and compared with cases of advanced countries, to verify that performer and the audience are main elements to develop performance art. And it is to show more effective safety measure after pointing out hazardous elements. Research change is limited to review only performance ones of all cultural facilities and to review accident cases from these places to show reasonable safety measures for stage facilities. Operation manager covers almost all of areas such as devices, management, despite a fact that they take charge of stage facilities, illumination, sounds, already. Some conclusions are as follows; 1) performance theatre-related regulations should be established again. domestic safety standards for performance theatre safety should be established. 2) characteristic and purpose of performance place should be clarified at the stage planning and design of them 3) operation expert performance place is required to be trained to cover emergency situation at any time.

• Journal of Power Electronics
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• v.10 no.1
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• pp.79-84
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• 2010

This paper presents a grid connected photo-voltaic system using a quasi-Z-source inverter (QZSI) for power stage reduction. The power stage can be reduced because of an additional shoot-through stage which is a characteristic of QZSI. Therefore, by utilizing a QZSI the system's efficiency can be increased. In this paper, for applying a QZSI to a PV system, control methods such as maximum power point tracking (MPPT), point of common coupling (PCC) current control and PWM are studied and verified through simulation and experiment. In order to explain the above controllers, the characteristics of a QZSI are first analyzed. Then the MPPT control technique with a modified P&O method, the PCC current control for the regulation of the dc-link capacitor voltage and the PWM methods for the proposed system are explained. The feasibility of the proposed algorithm is verified through simulation and experiment with a 3kW system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.1127-1130
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• 2003

In the last several centuries, humankind have been experienced the material abundance with a development of technical civilization and being industrialized quickly. During the process of this, environmental pollutant have occurred naturally so that humankind have more interests for environment pollutant. Air pollution caused by exhaust from a car is very harmful for human. Most of exhaust from a gasoline engine are $CO_x(CO+CO_2),\;NO_x(NO+NO_2)$, and THC(Total Hydrocarbon). The method to remove these kinds of noxious gases are so many thing such as the three catalysts, $NO_x$ catalysts, Filter and so on. However, although air pollution caused by exhaust from motorcycle have also occurred very much, there is no regulation for motorcycle. In this paper, we studied to remove $CO_x(CO+CO_2),\;NO_x(NO+NO_2)$, THC exhaust from a motorcycle using non-thermal plasma In the result, $NO_x(NO+NO_2)$ concentration was decreased approximately 70% and THC(Total Hydrocarbon) was removed about 40%.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.12
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• pp.277-284
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• 2012

In this paper, we analyzed various noise in the video stream system that have largely influence on EMI noise. We presented the remedy for these various noises and then designed the wireless video streaming system for a vehicle. To minimize EMI noise, we derived the improvement of noise characteristic from impedance matching, new design of the inner layer of the PCB line design and new design of high-speed data Interfaces. As a result, the final system showed 40[dBuV/m] and 47[dBuV/m] dB in the each regulation band.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.4
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• pp.475-482
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• 2012

This study was designed to elucidate the mechanism of the cytoprotective effect of the Palmul-tang (PMT) on glutamate induced cytotoxicity in rat C6 glial cells. We determined the increase of cell viability by PMT on glutamate-induced death of C6 glial cell. On some experiments, glutamate induced cell death to be an apoptotic phenomena characterized by G1 arrest in cell cycle, chromatin condensation, DNA fragmentation in C6 glial cells. However, pre-treatment of PMT inhibited characteristic apoptotic phenomena. One of the main mediator of glutamate-induced cytotoxicity was known to generation of reactive oxigen species. In this study, PMT attenuated generation of reactive oxigen species by glutamate through down-regulation of NOX1 expression in C6 glial cells. Furthermore, PMT regulated Bcl2 families and caspase proteins, which contribute the cell survival or death. This study suggests that PMT may be candidate for both of therapeutic and protective prescription.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.7
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• pp.3073-3076
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• 2012

Terpinen-4-ol is a terpene found in the rhizome of Plai (Zingiber montanum (Koenig) Link ex Dietr.). In this study apoptogenic activity and mechanisms of cell death induced by terpinen-4-ol were investigated in the human leukemic MOLT-4 cell line. Terpinen-4-ol exhibited cytotoxicity in MOLT-4 cells, with characteristic morphological features of apoptosis by Wright's staining. The mode of cell death was confirmed to be apoptosis by flow cytometric analysis after staining with annexin V-FITC and propidium iodide. A sub-G1 peak in DNA histograms of cell cycle assays was observed. Terpinen-4-ol induced-MOLT-4 cell apoptosis mediated through an intrinsic pathway involving the loss of mitochondrial transmembrane potential (MTP) and release of cytochrome c into the cytosol. In addition, terpinen-4-ol also induced apoptosis via an extrinsic pathway by caspase-8 activation resulting in the cleavage of cytosolic Bid. Truncated-Bid (tBid) translocated to mitochondria and activated the mitochondrial pathway in conjunction with down-regulation of Bcl-2 protein expression. Caspase-3 activity also increased. In conclusion, terpinen-4-ol can induce human leukemic MOLT-4 cell apoptosis via both intrinsic and extrinsic pathways.