• Tribology and Lubricants
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• 제30권1호
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• pp.52-58
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• 2014

Because food crops serve as the raw materials for biodiesel, the increasing use of biodiesel as an alternative fuel can lead to adverse effects such as food price inflation and may contribute to global starvation. To solve these problems, efforts are being made to explore various nonedible raw materials for producing biodiesel. Different raw materials impart different fuel characteristics to biodiesel. In this study, we synthesized pure fatty acid methyl ester (FAME), which is a biodiesel component, and then analyzed its fuel properties. The fuel properties of pure FAME would be useful in producing biodiesel from various new raw materials.

• Proceedings of the Korean Nuclear Society Conference
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• 한국원자력학회 2005년도 추계학술발표회
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• pp.197-198
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• 2005

• Proceedings of the KIEE Conference
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• 대한전기학회 2004년도 추계학술대회 논문집 전기물성,응용부문
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• pp.255-257
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• 2004

This paper was studied electromagnetic field distribution and damping of PD(Partial Discharge) signal in GIS(Gas Insulated Switchgear). Cut-off frequency of electromagnetic wave propagation modes were computed, electromagnetic field distribution of propagation modes in GIS by FEM(Finite Element Method) were simulated and simulated damping characteristic of electromagnetic waves in GIS by EMTP(Electromagnetic Transient Program) when generated PD pulse. Frequency band of $TE_{mn}/TM_{mn}$ modes were determinated by simulation results of electromagnetic field distribution and were discussed optimal position of UHF sensor from this results. Equivalent circuit was used to simulate signal damping of PD pulse in GIS by EMTP and compared with measured results in laboratory of KERI.

• Molecules and Cells
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• 제21권1호
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• pp.34-41
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• 2006

The neuronal localization of alpha-amino-3-hydroxyl-5-methyl-4-isoxazole propionic acid (AMPA) glutamate receptor (GluR) subunits is vital as they play key roles in the regulation of calcium permeability. We have examined the distribution of the calcium permeable AMPA glutamate receptor subunit GluR1 in the mouse visual cortex immunocytochemically. We compared this distribution to that of the calcium-binding proteins calbindin D28K, calretinin, and parvalbumin, and of GABA. The highest density of GluR1-immunoreactive (IR) neurons was found in layers II/III. Enucleation appeared to have no effect on the distribution of GluR1-IR neurons. The labeled neurons varied in morphology; the majority were round or oval and no pyramidal cells were labeled by the antibody. Two-color immunofluorescence revealed that 26.27%, 10.65%, and 40.31% of the GluR1-IR cells also contained, respectively, calbindin D28K, calretinin, and parvalbumin. 20.74% of the GluR1-IR neurons also expressed GABA. These results indicate that many neurons that express calcium-permeable GluR1 also express calcium binding proteins. They also demonstrate that one fifth of the GluR1-IR neurons in the mouse visual cortex are GABAergic interneurons.

• Proceedings of the KIEE Conference
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• 대한전기학회 1998년도 하계학술대회 논문집 C
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• pp.943-945
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• 1998

This paper presents a method of modeling of DSTATCON (Distribution-line Static Condenser) for installation in a specific plant and analyze the effectiveness of the DSTATCON from the viewpoints of voltage regulation and harmonic mitigation in a distribution line. For the reliable modeling, detailed information on distribution system and loads is performed by field measurements. The DSTATCON has been modeled according to the control algorithm of real controller. The effectiveness of the DSTATCON installation is verified by simulation using EMTDC.

• The Transactions of The Korean Institute of Electrical Engineers
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• 제65권3호
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• pp.397-403
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• 2016

Generally, an electrical distribution configuration is a radial system with one-way current in a distribution management system (DMS). All feeders in a DMS have tie-switches to make radial system. Sometimes, DMS should change a tie-switch for operation. In that case, the tie-switch has to be closed first; then a switch is opened as another tie-switch in order to prevent blackout for customers. At the moment when the tie-switch is closed, distribution system is operated in a loop state, not radial. Before the loop operation, DMS operator has to check any expected events for stable distribution system operation; and the most important event is a mis-operation of a protection relay. In addition, DMS operator should check voltage profile violation but a calculation method of section voltages had not been used. Thus, this paper proposes a calculation method of section voltages at a loop operation in a DMS. The proposed calculation algorithm is verified by Matlap Simulink.

• Current Applied Physics
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• 제18권11호
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• pp.1447-1450
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• 2018

The electron spin resonance (ESR) detects point defect of the In-Ga-Zn oxide (IGZO) like singly ionized oxygen vacancies and excess oxygen, and get spin density as a parameter of defect state. So, we demonstrated the spin density measurement of the IGZO film with various deposition conditions and it has linear relationship. Moreover, we matched the spin density with the total BTS and the threshold voltage ($V_{th}$) distribution of the IGZO thin film transistors. The total BTS ${\Delta}V_{th}$ and the $V_{th}$ distribution were degraded due to the spin density increases. The spin density is the useful indicator to predict $V_{th}$ instability of IGZO TFTs.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 12th Asian Congress of Fluid Mechanics
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• pp.42.6-43
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• 2008

• Proceedings of the KIEE Conference
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.888-890
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• 2003

In the distribution networks, it is required to develop compact and smart current and voltage sensors for compact and digital switchgears. The sensor developed newly adopt the priciple of rogowski coil for current sensing and resistive voltage divider for voltage sensing. The sensing characteristics and reliabilities were improved compared to conventional ones. In the near future, these voltage and current sensing apparatus will be widely used with electronic protection units for the distribution switchgear.

• Proceedings of the KIEE Conference
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.30-32
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• 2004

This paper describes control system design for the DH(dynamic voltage restorer) consisted of a diode rectifier and series inverter applied to 22.9kV distribution system. The DVR control system is consisted of the main two parts. One is a voltage event detector using a neural network and the other is deadbeat controller for the output voltage and current control of the DVR. A simulation model was developed for analyzing performance of the controller and the whole system. The results confirm that the DVR can restore load voltage under the fault of the distribution system.