• Transactions on Electrical and Electronic Materials
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• 제17권4호
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• pp.212-216
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• 2016

A reflective electronic display that uses negatively and positively charged particles has excellent bistability, a welldefined threshold voltage, and an extremely fast response time in comparison with other reflective displays. This type of display shows images through the movement of charged particles whose motion depends on the value of q/m (charge per mass for a particle). However, the ratio q/m can easily be changed by the forces acting on the charged particles in a cell of the panel and by friction that occurs after mixing oppositely charged particles and in the particle-insertion process. In this study, we propose a method to determine the appropriate range of q/m by using the reflectivity and response time of charged particles to modify q/m. In this manner, the electrical and optical properties of reflective displays are improved.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1990년도 추계학술발표회논문집
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• pp.63-67
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• 1990

Many characteristics of space charge in insulating materials which is the cause of insulation break down was measured quantita-tively. It was confirmed that injection charge of the electrode was trapped to form mainly space charge. In the present paper, collecting potential was determined by TSSP and mean depths of space distribution was investigated by measuring variation quantity of space charge under the different bias time, voltage and temperature. Experimental resuts was in good agreement with model analysis on a stedy state.

• Transactions on Electrical and Electronic Materials
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• 제6권3호
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• pp.87-90
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• 2005

$SiO_2$ via-hole etching with a high aspect ratio is a key process in fabricating ULSI devices; however, accumulated charge during plasma etching can cause etching stop, micro-loading effects, and charge build-up damage. To alleviate this concern, charge-up damage sensor was fabricated for the ultimate goal of real-time monitoring of accumulated charge. As an effort to reach the ultimate goal, fabricated sensor was used for electrical potential measurements of via holes between two poly-Si electrodes and roughly characterized under various plasma conditions using statistical design of experiment (DOE). The successful identification of potential difference under various plasma conditions not only supports the evidence of potential charge-up damage, but also leads the direction of future study.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제8권12호
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• pp.277-286
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• 2019

무인항공기는 사물인터넷 분야에서 중요한 발명중의 하나이며 많은 응용에서 사용되고 있다. 특히 소형 무인항공기(드론)는 배터리로 동작을 하기 때문에 서비스 도중 또는 서비스간에 충전소에서 배터리 충전과 배터리 교체가 필요하다. 배터리 충전소가 제한된 상황에서 먼저 충전할 드론을 스케쥴링하고 충전된 배터리를 할당하는 문제는 중요하다. 본 논문에서는 효율적인 드론의 배터리 충전 스케쥴링 알고리즘을 제안하였다. 드론을 위한 배터리 충전 스케쥴링 알고리즘의 기본 아이디어는 실시간처리 환경에서 마감시간을 만족하기 위하여 마감시간을 고려함(EDF)과 동시에 대기시간을 줄이기 위해서 충전시간을 동시에 고려(SJF)하였다. 즉, 마감시간이 짧을수록 그리고 충전시간이 짧을수록 높은 우선순위를 부여하여 마감시간 준수율을 높이고 평균 대기시간을 줄임으로서 결과적으로 마감시간 준수율향상과 대기시간 단축이라는 두가지 측면을 동시에 만족할 수 있는 기법을 고려하였다. 이미 충전된 배터리의 할당에서는 충전시간이 길수록 높은 우선순위를 배정하므로서 평균 대기시간을 줄일 수 있다. 시뮬레이션 결과 제안 알고리즘을 이용하여 마감시간 준수율과 평균 대기시간 측면에서 기존 알고리즘(EDF와 SJF)과 비교하여 좋은 성능을 보임을 확인하였다. 시뮬레이션 결과를 바탕으로시스템 파라메터와 사용자 요구사항에 따라 배터리 충전 스케쥴링과 배터리 할당 알고리즘을 합리적으로 선택할 수 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 추계학술대회 논문집 전기설비전문위원
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• pp.229-230
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• 2008

The investigations included the measurements of volume currents and also internal space charges on epoxy samples of mm thicknesses. The current versus time relations were shown to correspond well with classical forms of dielectric response such as the Curie-von Schweidler model. After the time transient, near steady currents were extremely small and exhibited a significant temperature dependence, similar in relation to the Poole-Frenkel hoping transport model. Equivalent resistances were on the order of $10^{19}$ ohms and represent very weak charge transport. Electrically stimulated acoustic waves were used to quantify the small internal charges that would accumulate within the epoxy. There was a notable homocharge near both anode and cathode. The dielectric response and the internal charge were related to show a consistent model for charge transport within unfilled epoxy.

• 조명전기설비학회논문지
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• 제29권9호
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• pp.96-102
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• 2015

This paper presents battery charging method using 3-phase AC-DC boost converter. General battery charging method is that charging the battery voltage to the reference voltage according to the constant current(CC) control, when it reaches the reference voltage, charging the battery fully according to the constant voltage(CV) control. However, battery chaging time is increased because of the battery impedance, constant current charging section which shoud take the large amount of charge is narrow, and constant voltage charging section which can generate insufficient charge is widen. To improve this problem, we proposes the method to reduce the charging time according to the SOC(State of Charge) estimation using battery impedance.

• 한국군사과학기술학회지
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• 제18권5호
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• pp.566-573
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• 2015

The most important factor for the penetration performance of shaped charge is the liner design. By designing the liner to have properties of both high jet tip velocity and long jet break-up time, the better penetration performance could be acquired. Usually it is very difficult to satisfy above two conditions simultaneously. In this study, the liner with the shape of ogive was developed to have relatively larger jet mass compared to the conventional trumpet liner. The designed shaped charge showed jet properties with high jet tip velocity and long jet break-up time by using ogive liner and wave shaper. A commercially available hydro-dynamic code AUTODYN-2D was used for numerical analysis of jet formation. The flash X-ray test and the static penetration test were conducted to verify the results of numerical analysis.

• 한국콘텐츠학회논문지
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• 제9권1호
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• pp.304-311
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• 2009

본 연구에서는 시간의 경과에 기반을 둔 누적감가상각비율함수를 이용한 새로운 감가상각방법을 제안한다. 제안된 방법은 임의의 시점에서의 누적감가상각금액을 계산해내는 방법으로, 현재 사용되고 있는 방법들이 가지고 있는 문제점들을 해결할 수 있을 뿐만 아니라, 시간의 경과에 따라 매 회기의 감각상액이 일정하거나, 점차 감소하거나, 점차 증가하는 모든 경우를 체계적으로 계산해낼 수 있다. 이 방법을 사용하면 각 자산의 특성에 맞는 다양한 감각상각형태를 합리적으로 선택하여 사용할 수 있고, 기중에 자산을 취득하거나 처분하는 경우에도 체계적이고 일관성 있게 감가상각비를 상계할 수 있게 된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.2311-2312
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• 2008

The investigations included the measurements of volume currents and also internal space charges on epoxy samples of mm thicknesses. The current versus time relations were shown to correspond well with classical forms of dielectric response such as the Curie-von Schweidler model. After the time transient, near steady currents were extremely small and exhibited a significant temperature dependence, similar in relation to the Poole-Frenkel hoping transport model. Equivalent resistances were on the order of 1019 ohms and represent very weak charge transport. Electrically stimulated acoustic waves were used to quantify the small internal charges that would accumulate within the epoxy. There was a notable homocharge near both anode and cathode. The dielectric response and the internal charge were related to show a consistent model for charge transport within unfilled epoxy.

• 전기학회논문지
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• 제60권2호
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• pp.320-324
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• 2011

A digital technique is adopted to calibrate the current mismatch of the charge pump (CP) in phase-locked loops. A 2 GHz charge pump PLL (CPPLL) is used to justify the proposed calibration technique. The proposed digital calibration technique is implemented simply using a counter. The proposed calibration technique reduces the calibration time by up to a maximum of 50% compared other with techniques. Also by using a dual-mode CP, good current matching characteristics can be achieved to compensate $0.5{\mu}A$ current mismatch in CP. It was designed in a standard $0.13{\mu}m$ CMOS technology. The maximum calibration time is $33.6{\mu}s$ and the average power is 18.38mW with 1.5V power supply and effective area is $0.1804mm^2$.