• Proceedings of the KIEE Conference
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• 대한전기학회 2001년도 추계학술대회 논문집 전기물성,응용부문
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• pp.149-151
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• 2001

This paper presents the results of characteristics of the solid-core and suspension insulators for the reliability estimation. The various analytic techniques. such as ICP, XRD, SEM, EDS, were applied for the purpose. The alumina content of solid-core insulator was less than that of suspension insulator The cristobolite was crystallized only in solid-core insulator. The average pore size of solid-core insulator was larger than that of suspension insulator. However, the numbers of pore were fewer in the solid-core insulator.

• Proceedings of the Materials Research Society of Korea Conference
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• 한국재료학회 2011년도 추계학술발표대회
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• pp.19.1-19.1
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• 2011

We report on the metal-insulator transition that occurs as a function of film thickness in ultrathin $La_{0.75}Sr_{0.25}VO_3$ films. The metal-insulator transition displays a critical thickness of 5 unit cell. Above the critical thickness, metallic films exhibit a temperature driven metal-insulator transition with weak localization behavior. With decreasing film thickness, oxygen octahedron rotation in the films increases, causing enhanced electron-electron correlation. The electron-electron correlations in ultrathin films induce the transition from metal to insulator in addition to Anderson localization.

• Proceedings of the KIEE Conference
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1534-1535
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• 2011

Composite hollow insulator consist of an insulating tube bearing the mechanical load protected by an elastomer housing the loads being transmitted to the tube by metal fittings. The core processes are comprised briefly and the electrical and mechanical performance were examined according to the IEC standards. In this study, we have manufactured the composite hollow insulator, and carry out the insulator and busing type test according to the IEC standards. Comprehensive approach followed by the test results would give feasible hollow composite insulator compliable to the IEC standards.

• Proceedings of the KIEE Conference
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• 대한전기학회 2008년도 학술대회 논문집 정보 및 제어부문
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• pp.373-374
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• 2008

To prevent an insulator failure, a new inspection system is presented for 154kV insulator strings. The inspection system detects fault insulators by measuring resistance and voltage of each insulators in the 154kV insulator string. The inspection instrument obtains autonomously insulation resistance and assigned voltage along the insulator string. The insulator inspection instrument is manipulated by two operators. In addition, a set of mechanism is applied to prevent the system from being reset under live-line condition. We confirmed its effectiveness through experiments.

• Proceedings of the KIEE Conference
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• 대한전기학회 2008년도 Techno-Fair 및 합동춘계학술대회 논문집 전기물성,응용부문
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• pp.191-192
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• 2008

In this paper, we investigated on the characteristics and assessment of the insulators damaged by hitting tester(ST-100, Sharp-Eng, KOR). It made that an apparatus act on KS C 3801 for the damaged characteristics and assessment of insulators according to external scattering objects. There are selected 255mm glass insulators and 254mm porcelain insulators as the specimen. The hitting angles of the damaged insulator by pendulum weight are at $72^{\circ}$. At these points, velocity of pendulum weight is about 3.04m/sec and the force is 58.16N. At the hitting angle of 26 degrees, glass insulator is diffused the vibration within it but porcelain insulator is not. The inside vibrations of glass insulator and porcelain insulator are as like as two at the hitting angle of 53 degrees. The damaged glass insulator at the hitting angle of 72 degrees hardly is not diffused.

• The Transactions of the Korean Institute of Electrical Engineers C
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• 제49권1호
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• pp.59-63
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• 2000

For the Mo-tip field emitter array, the method by which the geometrical structure of the gate insulator wall could be modified in order to improve field emission properties(turn-on voltage and gate leakage current). The device having a gate insulator of complex shape, which means the combined geometrical structure with round shape made by wet etching and vertical shape made by dry etching processes, was fabricated and the field emission properties of the three kinds of devices were compared. As a result, the electric field applied to tip apex could be increased and gate leakage current could be decreased by employing the gate insulator having geometrical wall structure of mixed shape. Finally, the obtained empirical results were analyzed by simulation of electric field distribution at/near the tip apex and gate insulator using SNU-FEAT simulator.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.194-197
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• 2002

Applying dual layer insulator on plastic substrates improved electrical characteristics of organic thin film transistor(TFT). A high-quality silicon dioxide(SiO$_2$) suitable for a insulator was deposited on plastic substrates by e-beam evaporation at 110$^{\circ}C$. The insulator film which was treated by N$_2$ annealing at 150$^{\circ}C$ showed excellent I-V, C-V characteristics. The dual layer insulator structure of polyimide-SiO$_2$ improved the roughness of SiO$_2$ surface and showed very low leakage current. In addition, the flat band voltage has been reduced from -2.5V to about 0.5V.

• Proceedings of the KIEE Conference
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• 대한전기학회 2001년도 하계학술대회 논문집 C
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• pp.1808-1810
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• 2001

Because of its advantages such as more safe better electrical properties, lighter and easier to handle etc. than conventional ceramic materials, the development and application of composite insulator to the distribution and transmission system have been rapidly increased lately. In this paper, we reviewed performance evaluation on composite hollow insulator for extra high voltage based on IEC 61462 Technical Report 2, prospected to be published as international standards of Insulator for $SF_6$ GIS, Transformer, Arrestor etc, having been prepared by IEC technical committee 36 : insulator.

• Proceedings of the KSR Conference
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.46-49
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• 2010

Fiber Reinforced Plastic (FRP) insulator has a higher performance than porcelain. It is only used in domestic AC 25 kV electric railway system. Seoul Metro has developed DC 1500 V FRP insulator since 2008. FRP support insulator of flexible property is affected by the wind in tunnel. A wind tunnel test was carried out to measure influence on the insulator housing when the train passed by. The test results showed that the wind which is resulted from the passing train had a little impact on the FRP insulator shed movements.

• Proceedings of the KSR Conference
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.864-874
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• 2007

Suspension insulator in Catenary Trolley Wire Systems must have two characteristics, electric insulation and mechanical endurance. Because suspension insulator is used in supporting and insulating position between power supply parts and earth conducted supporting parts. The insulator's electric characteristics can be influenced by surface pollution and damage from the environment such as humidity, dust, smoke, salt. etc. And, the insulating parts can be electrically short. These electrically damaged insulator can cause serious accidents that have far-reaching effect. So appropriate management basis of suspension insulator is needed. And we present appropriate cleaning and the changing period of suspension insulator on the basis of actual data.