• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 하계종합학술대회 논문집(2)
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• pp.509-512
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• 2004

This paper proposed a new solid State Relay(SSR) structure that can replace the conventional SSR as a power IC. The photodiode arrays, the main part of this structure, were designed and integrated in the same power It chip with the output parts, LDMOSFET and BJT, on a SOI substrate. The fabrication of this input part shared the same output LDMOSFET fabrication processs, except the additional deposition of Silicon nitride($Si_3N_4$) for the photo-detection part. According to LED illumination intensites and photo detecting areas, we could obtain voltage of 0.49V ${\~}$0.52V and current of 5.5uA ${\~}$ 108uA respectively from the fabricated unit photodiode. The maximum value of the voltage and the current we could obtain from the photodiode array were 3.58V and 24.4uA respectively, and the voltage was enough to operate the output LDMOSFET

• Journal of Power Electronics
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• 제10권1호
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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.

• Corrosion Science and Technology
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• 제2권1호
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• pp.7-11
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• 2003

Photoelectrochemical response and electrochemical impedance behavior was investigated for passive film formed on sputter-deposited Cr alloy in $0.1kmol{\cdot}m^{-3}$. Photoelectrochemical action spectrum could be separated into two components, which were considered to be derived from $Cr_2O_3$ ($E_g\sim3.6eV$) and $ Cr(OH)_3 $ ($E_g\sim2.5eV$). The band gap energy, $E_g$, of each component was almost constant for various applied potentials. polarization periods and alloying additives. The photoelectrochemical response showed negative photo current for most potentials in the passive region. Therefore, the photo current apparently exhibited p-typesemiconductor behavior. On the other hand, Mort-Schottky plot of the capacitance showed positive slope, which means that passive film formed on Cr alloy has n-type semiconductor property. These apparently conflicting results are rationally explained assuming that the passive film on Cr alloy formed in the acid solution has n-type semiconductor property with a fairly deep donor level in the band gap and forms an accumulation layer in the most of potential region in the passive state.

• 센서학회지
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• 제17권5호
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• pp.387-395
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• 2008

An optic module system is developed adopting multiple colorimetry units for the measurement of multi-pad urinalysis dipsticks. Multiple photometry system instead of moving mechanisms has the advantages of system reliability and simplicity as well as economic aspects due to the recent development of economic color light emitting diodes and stable photo sensors. An integration amplifier with programmable integration time, a current source circuit with selectable and stable current settings were connected through analog multiplexers to thirty light emitting diodes for illumination and ten photo transistors for reading each strip pad. All the circuits are controlled by a microprocessor through a simple set of serial communication commands. The detect ability is eighteen times better than the minimum color difference of the test grading which is 0.013 in urobilinogen in the color space defined in this paper.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.793-796
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• 2003

The electronics of a mobile robot ill nuclear facilities is required to satisfied the reliability to sustain survival in its radiation environment. To know how much radiation the robot has been encountered to replace sensitive electronic parts, a dosimeter to measure total accumulated dose is necessary. Among many radiation dosimeters or detectors, semiconductor radiation sensors have advantages in terms of power requirements and their sires over conventional detectors. This paper describes the use of the radiation-induced threshold voltage change of a commercial power pMOSFET as an accumulated radiation dose monitoring mean and that of the photo-current of a commercial PIN Diode as a dose-rate measurement mean. Commercial p-type power MOSFETs and PIN Diodes were tested in a Co-60 gamma irradiation facility to see their capabilities as radiation sensors. We found an inexpensive commercial power pMOSFET that shows good linearity in their threshold voltage shift with radiation dose and a PIN diode that shows good linearity in its photo-current change with dose-rate. According to these findings, a radiation hardened hybrid electronic radiation dosimeter for nuclear robots has been developed for the first time. This small hybrid dosimeter has also an advantage in the point of view of reliability improvement by using a diversity concept.

• 한국화재소방학회논문지
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• 제24권1호
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• pp.46-53
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• 2010

주택화재 예방을 위해 10년 동안 전지 교체 없이 지속적으로 유지가 되도록 회로 설계된 저소비 전력의 광전식 단독경보형감지기의 개발 경험을 보고한다. 시장규모가 국내에 비해 100배 이상 큰 일본을 대상으로 인증을 받도록 개발되었고, KFI 규격과 JFEII에 대한 시험 규격 비교 검토도 수행되었다. 감지기의 경보는 부저와 표시 LED를 통해 표현되며, 경보와 고장 및 화재 시의 동작 주기와 동작 시간이 기술되어 있다. 소비 전류를 줄이기 위해 적용된 주요 전자 회로 부분과 구현된 감지기의 동작 특성 분석 결과가 나타나 있다. 또한, 구현된 감지기의 소비 전류 측정값과 전지의 방전 특성 실험 결과를 통해 10년 동안 적용 가능함을 나타내었다.

• Archives of Plastic Surgery
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• 제50권4호
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• pp.443-444
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• 2023

Point-of-care photography and photo sharing optimize patient outcomes and facilitate remote consultation imperative for resident surgeons. This literature review and external pilot survey study highlight the risks associated with current practices concerning patient privacy and biometric security. In a survey of 30 plastic surgeon residents and attendings, we found that the majority took photos of patients with their iPhones and shared them with colleagues via Apple iMessage. These findings corroborate previous reports and highlight a lack of physician user acceptance of secure photo-sharing platforms. Finally, we frame a successful example from the literature in the context of a postulated framework for institutional change. Prioritizing the privacy and safety of patients requires a strategic approach that preserves the ease and frequency of use of current practices.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 추계학술대회 논문집
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• pp.156-159
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• 1996

Detection of displacement current across spreading organic Azodyes was investigated using a displacement current measuring technique. It was found that displacement current was generated only when dynamical motion of organic monolayers was initiated on the water surface by photo-isomerization and application of surface pressure. Displacement current was generated only in the range before the initial rise of Surface pressures for azo dyes(8A5H) we are using the Langmuir-Blodgett(LB) films deposition apparatus. We are obtain displacement current by pressure and light

• 한국진공학회지
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• 제6권2호
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• pp.103-108
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• 1997

본 연구에서는 2단계 실리콘 건식식각 공정과 게이트 절연막으로 열산화막과 tetraethylorthosilicate(TEOS) 산화막의 이중막을 사용하고, 스핀-온-그래스 (Spin-on-glass:SOG) 에치백(etch-back) 공정에 의하여 게이트를 제작하는 새로운 방법을 통하여 실리콘 전계방출소자를 제작하고 그 특성을 분석하였다. 게이트 절연막의 누설전류 를 감소시키면서 팁과 게이트의 간격을 줄이는 구조인 이중 게이트 절연막을 형성하기 위하 여 팁 첨예화 산화 공정후 낮은 점도의 감광막(photo resist)을 시료에 도포한 후, $O_2$ 플라 즈마 에싱(ashing)하는 공정을 채택하였다. 이러한 공정으로 제작된 에미터 팁의 높이와 팁 반경은 각각 1.1$\mu\textrm{m}$와 100$\AA$정도이었으며, 256개 팁 어레이에서 전계방출의 문턱전압은 40V 이하이었다. 60V의 게이트전압에서 23$\mu\textrm{A}$(즉, 90nA/팁)의 높은 아노드 전류를 얻을 수 있었 다. 이때, 게이트 전류는 아노드전류의 약0.1%이하였다. 개발된 공정기술로 게이트 개구도 크게 감소시켰을 뿐 아니라, 게이트 누설전류를 현저히 감소시켰다.

• 한국정보통신학회논문지
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• 제11권2호
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• pp.322-329
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• 2007

본 논문에서는 디지털 의료 영상 및 진단 분야 그리고 산업용으로도 활용 가능한 싱글 포톤 계수형 영상센서를 $0.18{\mu}m$ triple-well CMOS(Complementary Metal Oxide Semiconductor) 공정을 사용하여 설계하였다. 설계된 Readout 칩용 싱글 픽셀은 디지털 X-ray 이미지 센서모듈을 간단화 하기 위해 단일 전원전압을 사용하였으며, Preamplifier의 출력 전압인 signal voltage(${\Delta}Vs$)를 크게 하기 위해 Folded Cascode CMOS OP amp를 이용한 Preamplifier를 설계하였으며, 기존의 Readout 칩 외부에서 인가하던 threshold voltage를 Readout 칩 내부에서 생성해 줄 수 있도록 Externally Tunable Threshold Voltage Generator 회로를 새롭게 제안하였다. 그리고, Photo Diode에서 발생하는 Dark Current Noise를 제거하기 위한 Dark Current Compensation 회로를 제안하였으며, 고속 counting이 가능하고, layout 면적이 작은 15bit LFSR(Linear Feedback Shift Resister) Counter를 설계하였다.