• Transactions on Electrical and Electronic Materials
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• 제7권5호
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• pp.235-239
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• 2006

Charge dynamics in polymeric materials after aged under ac electric field using the pulsed electroacoustic (PEA) technique is reported. The emphasis is placed on charge decay. The charge dynamics of the ac aged additive free low density polyethylene (LDPE) samples under dc bias differ from the sample without ac ageing, indicating changes brought in by ac ageing. It is believed that a slow decay rate of charge in the ac aged sample is related to the formation of deep traps in the material. However, chemical analysis by infrared spectroscope (FTIR) and Raman microscope reveals no significant chemical changes taken place in the bulk of the material after ac ageing. Further experiments on irradiated LDPE have revealed a similar behaviour, i.e. the charge decay is slower in irradiated samples than that of fresh sample. The findings presented clearly indicate that space charge measurement can be used as a diagnostic tool to monitor ageing in polymeric materials.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 학술대회 논문집 전문대학교육위원
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• pp.108-112
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• 2000

The electric charge generated by flowing insulation liquid can create hazardous spark in transfer line and receiving tank etc. These electrification has generally been measured by current measurement with a ammeter connected to the receiving tank. This paper reports on the experimental result obtained by this method. As a experimental results: The injected charge value for unit volume increased in the following condition, the edge of the needle electrode was sharp, the number of needle electrode was fewer, the edge of the needle electrode was located close to the inside wall. When the charge density in the charge reducer is constant, electrode current and electrode potential by the charge injection from outside increase with increasing of oil velocity and streaming current. The electrode potential in charge reducer is made maximum value at edge point of reducer inside and minimum value at center line of charge reducer.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.497-500
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• 2001

Due to their better photosensitivity in X-ray, the amorphous selenium based photoreceptor is widely used on the X-ray conversion materials. It was possible to control the charge carrier transport of amorphous selenium by suitably alloying a-Se with other elements(e,g. As, Cl). The charge transport properties of amorphous Selenium is decided on hole which is induced from metal to selenium in metal-selenium junction and which is transferred in a-Se bulk. This phenomenon is resulted of changing electric field owing to increasing of space charge by deep trap of a-Se bulk. In this paper, We dopped the chlorine to compensate deep hole trap and deposited blocking layer using dielectric material to prevent from increasing space charge for injection charge between metal electrode and a-Se layer. We compared space charge and the decreasing of trap density through measuring dark and photo current.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.350-352
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• 2007

Modularized charge equalization converter for HEV lithium-ion battery cells is proposed in this paper, in which intra-module and inter-module charge equalization can be achieved at the same time. For intra-module charge equalization, the conventional flyback DC/DC converters of low power and small size are employed, in which all of the primary sides are coupled in parallel for selective charge of the specific under charged cell within the module. For inter-module charge equalization, the flyback DC/DC converters are also added, in which all the secondary windings are electrically linked in parallel for automatic charge balancing among the modules. An engineering sample of forty cells hiring the proposed cell balancing scheme is implemented and its experimental result shows that the proposed modularized charge equalization circuit has good cell balancing performance.

• 대한기계학회논문집A
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• 제38권1호
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• pp.37-44
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• 2014

본 연구에서는 전기이륜차의 1회충전주행거리를 알아보기 위해 도로 주행시험과 차대동력계(Chassis Dynamometer) 주행시험을 하였다. 도로주행시험은 대전시(Daejeon Metropolitan City)의 도로 중 대표적인 3가지 루트에서 주행시험을 하였다. 차대동력계를 이용한 CVS-40모드 주행시험의 경우 도로 부하조건을 다양하게 설정하여 CVS-40 모드주행을 실시하였다. 본 연구를 통하여 도로에서의 전기이륜차의 1회 충전주행거리(Per-Charge Range Testing)를 확인하고, 차대동력계 도로부하 설정방법에 따른 주행거리 및 에너지소비효율을 측정하였다. 이를 통해 실도로 주행시험과 차대동력계 주행시험을 비교하여, 차대동력계 실험에서도 전기이륜차 1회충전주행거리시험이 실도로에서의 주행조건과 근접한 결과를 갖는 도로부하 설정에 대해 연구하였다.

• 한국융합학회논문지
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• 제5권3호
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• pp.23-27
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• 2014

최근에 스마트폰과 디바이스의 무선충전에 대한 관심이 높아지고 있으며, 많은 기업들이 무선충전을 개발하고 있다. 무선충전은 앞으로 모바일기기뿐만 아니라 노트북 청소기 등 거의 모든 전자제품으로 적용 범위가 확대될 것이다. 무선충전 전기자동차도 올해 본격적으로 선을 보일 예정이다. 이렇듯 무선충전은 연관시장이 무궁무진하다. 세계 10대 유망기술에 포함되어 있는 무선충전은 매년 100% 이상 급성장할 전망이라고 한다. 하지만 그에 따라 존재하는 기술적 한계점과 인체 유해성에 대한 보안위협을 분석해 안전한 환경에서 사용할 수 있도록 해야 하고 각종 제도적 보안도 마련해야 한다. 무선충전에 대한 표준화와 보안대책요구사항은 체계적이지 않다. 본 논문은 모바일기기에서 자기공진방식의 무선충전의 보안 위협과 보안요구사항을 정의해 분석하고자 한다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1999년도 학술대회논문집-국제 전기방전 및 플라즈마 심포지엄 Proceedings of 1999 KIIEE Annual Conference-International Symposium of Electrical Discharge and Plasma
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• pp.141-144
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• 1999

This paper offer fundamental ones about insulation diagnosis with electromagnetic wave, when discharges occurred. To simulate Partial-Discharge(PD), It is used needle-plane electrode in air. As the voltages applied, measure the electromagnetic wave with monopole antenna and analysis its fundamental characteristics, then, acquired data were operated. The results presented as the form of graph, and the magnitude of charge when occurred PD simultaneously. In conclusion, when the magnitude of charge over 100[pC], the electric field strength changed, and then the magnitude of charge and the electric field strength increased samely.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1330-1332
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• 1994

In order to investigate the properties of electrical conduction and space charge in crosslinked polyethylene film, we were observed the specimen with 200[${\mu}m$] thickness. The electrical conduction properties of specimen were measured temperature range from 30 to $110[^{\circ}C] $as well as $10^{-2}$ - 1 [MV/cm] of electric field. The investigations on influence of space charge were carried out at room temperature and $60 [^{\circ}C]$.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.661-662
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• 2006

This paper introduces a CMOS clock driver that shows a high efficiency of electric power (lower power consumption) with the supply of lower voltage(VDD), by taking advantage of charge recycling technology. Comparing with the existing structure, this driver showed the improved maximum efficiency of electric power; 72% and 68%, with the supplied voltage of 1.8v and 1.2v, respectively. Since the output waveform shows the tri-state operating region, utilization is expected in the digital integrated circuits.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.373-374
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• 2008

Insulating polymers and their composites have been widely used in various electric apparatus or cables. Recently, the effects of interfaces (metal/insulator or insulator/insulator interfaces) on electrical insulation have attracted much attention. However, interfacial phenomena in actual insulation systems and their physical backgrounds are not well understood yet. In this paper, the behaviour of charge carriers near the metal/polymer interface and its effects on conduction and breakdown phenomena are discussed. The metal/polymer interface strongly affects carrier injection, space charge formation and breakdown phenomena. Based on their experimental results, the physical backgrounds of the interfacial phenomena are explained.