• 한국전기전자재료학회논문지
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• 제30권5호
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• pp.270-275
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• 2017

Current progress in the development of semiconductor technology in applications involving high electron mobility transistors (HEMT) and power devices is hindered by the lack of adequate ways todissipate heat generated during device operation. Concurrently, electronic devices that use gallium nitride (GaN) substrates do not perform well, because of the poor heat dissipation of the substrate. Suggested alternatives for overcoming these limitations include integration of high thermal conductivity material like diamond near the active device areas. This study will address a critical development in the art of GaN on diamond (GOD) structure by designing for ideal heat dissipation, in order to create apathway with the least thermal resistance and to improve the overall ease of integrating diamond heat spreaders into future electronic devices. This research has been carried out by means of heat transfer simulation, which has been successfully demonstrated by a finite-element method.

• 대한방사선기술학회지:방사선기술과학
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• 제43권1호
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• pp.15-21
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• 2020

This study was purpose to evaluation of Modulation Transfer Function in Measurements by using the International electrotechnical commission standard(IEC 62220-1) which were edge device each angle by using edge method. In this study was Aero(Konica, Japan) image receptor which is a indirect Flat panel detector(FPD) was used. The size of matrix 1994 × 2430 (14"× 17" inch) which performed 12 bit processing and pixel pitch is 175 ㎛. The results of shown as MTF measurements at IEC standard. The amount of data seemed reasonable and at an MTF value of 0.1 the spatial frequencies were 2.56 cycles/mm at an angle of 2.4°. MTF value of 0.5 the spatial frequencies were 1.32 cycles/mm at an angle of 2.4°. This study were to evaluate MTF by setting each angle 2.0°~2.8° degrees the most effective optimal edge angle and to suggest the quantitative methods of measuring by using IEC.

• 전자공학회논문지
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• 제50권3호
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• pp.35-41
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• 2013

$0.18-{\mu}m$ CMOS 반도체 공정을 이용하여 신체에 깊이 이식되어 있는 deep implant 의료 전자기기에서의 무선전력전달을 위한 고효율의 다단 정류기 (multi-stage rectifier)를 구현하였다. 세 개의 단계로 이루어진 정류기는 cross-coupled 된 구조를 이용하여 외부에서 전달되는 작은 AC 입력 신호를 boost하여 1.2-1.5 V의 DC 출력 신호를 implant 전자기기로 전달한다. 설계 된 정류기는 13.56 MHz에서 0.6-Vpp의 작은 RF 입력 신호와 $10-k{\Omega}$의 load 저항이 연결 된 측정 환경에서 최대 70 %의 전력 변환 효율을 달성하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.701-705
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• 2002

In order to realize full color display, two approaches were used. The first method is the patterning of red, green, and blue emitters using a selective deposition. Another approach is based on a white-emitting diode, from which the three primary colors could be obtained by micro-patterned color filters. White-light-emitting organic light emitting devices (OLEDs) are attracting much attention recently due to potential applications such as backlights in liquid crystal displays (LCDs) or other illumination purposes. In order for the white OLEDs to be used as backlights in LCDs, the light emission should be bright and have Commission Internationale d'Eclairage (CIE) chromaticity coordinates of (0.33, 0.33). For obtaining white emission from OLEDs, different colors should be mixed with proper balances even though there are a few different methods for mixing colors. In this study, we will report a white organic electroluminescent device based on an incomplete energy transfer. In which the blue and green emission come from the same layer via incomplete energy transfer.

• 대한전자공학회논문지
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• 제22권3호
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• pp.68-76
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• 1985

전하 결함 소자를 이용한 16×16 이차원 영상 감지 소자가 제작되었다. 제작된 소자는 2상(two-Phase)의 전극 구조로 제작 되었고 프레임 이동(frame transfer) 방식으로 동작한다. 표면 전위차를 얻기위해 이온 주입을 했고 NMOS공정을 따라 제작되었다. 영상을 얻기위한 시스템은 광학 렌즈 클럭 발생 및 구동 회로, 계단형 신호 발생기로 이루어지는데, EPROM을 사용하여 클럭 발생회로를 간단하게 하였다. 영상 시스템을 사용하여 오실로스코프 화면에 알파베트를 표시할 수 있었다. 소자의 특성으로 전하 이동 손실률과 암전류를 측정하였다.

• 스마트미디어저널
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• 제1권4호
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• pp.8-17
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• 2012

본 논문에서는 모바일 기기에서 사용자 경험의 향상을 위해 다중 진동신호를 활용하는 연구로, 포항공과대학교 햅틱스 및 가상현실 연구실의 '다중 진동자를 사용한 촉각 흐름'과 '실시간 이중 채널 촉감 음악 재생기'의 연구 현황을 소개한다. '다중 진동자를 사용한 촉각 흐름'은 여러 개의 진동자를 사용하여 흐르는 듯한 진동을 생성함으로써 다수의 구분 가능한 진동 신호를 제공할 수 있으며 이를 통한 정보 전달력의 향상을 도모할 수 있다. '실시간 이중 채널 촉감 음악 재생기'는 음악적 신호를 진동 신호로 변환하여 제공함으로써 사용자들로 하여금 더 나은 경험을 제공할 수 있다. 이러한 사례들은 향후 예상되는 모바일 기기에서의 더 많은 정보 전달과 더 나은 사용자 경험에 대한 요구를 충족시키기 위한 좋은 예가 될 수 있을 것으로 기대된다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.910-913
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• 2009

This paper examines attaching speed, detaching speed and contact time which affected in the ink transfer ratio and presents the best conditions for fabrication process of electrodes with Ag-ink using microcontact printing method. In conclusion, it shows the best printing characteristic by two conditions. One of condition is the attaching speed have to within less than 1mm/s and the detaching speed is high velocity as 1000mm/s and the contact time is taken about the minimum time when inking process. Another condition is the attaching speed have to within more than 100mm/s and the detaching speed have to within less than 1mm/s and the contact time is longer than 30second when the printing process. As using these condition and the stamp sized 5cm${\times}$5cm, it was possible for printing equally until $30{\mu}m$ of width. The printed thickness of a electrode was about 300 to 500 nm, the surface roughness was about dozens nm under 50 nm.

• 한국유체기계학회 논문집
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• 제18권1호
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• pp.29-36
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• 2015

Recently, Stirling engines are emerging as a key device for power conversion of renewable energy or waste energy. This study develops a LTDSE(Low Temperature Differential Stirling Engine) using a water spray for higher heat transfer and performs load performance tests for various flow rates and temperatures of hot water spray for variable engine loads emulated by a mechanical friction device. Internal temperature and pressure, working frequency and inlet and outlet temperature of the supply water are measured. As a result, the increases in flow rate and temperature of hot water respectively enhance the power output, efficiency and the working frequency, while the increasing engine load leads to decreases in working frequency but increases in the pressure amplitude. Eventually, it is revealed there exists a maximum shaft power of the test engine.

• 전기학회논문지
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• 제62권2호
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• pp.196-200
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• 2013

In this paper, the design of PRT vehicle power supply system is discussed. Since there is no power feeding line facilities in PRT system under development, the PRT vehicle must have its own energy storage device on board. For the energy storage device, ultra-capacitor bank is applied due to its fast charging capability and long life time. Charging the Ultra-capacitor bank is performed by wireless inductive power transfer system. The capacitor bank is charged up in less than 10 seconds when the vehicle is traveling by passenger stations. In this paper the design of the ultra-capacitor bank and the wireless inductive power transfer system for the PRT vehicle are discussed. Tests are conducted for the both system and the result shows the efficiency of the wireless inductive power transfer system is higher than 80%.

• 한국광학회지
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• 제17권5호
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• pp.475-479
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• 2006

본 논문에서는 폴리머 링 광공진기를 이용하여 집적광학형 K-band용 마이크로웨이브 대역통과 필터를 제안하고 구현하였다. 특히, 열광학 효과를 이용하여 광공진기의 공진파장을 변화시킴으로써 대역통과 필터의 전달특성을 전기적으로 조절하였다. 측정된 필터의 중심주파수는 20 GHz, 소멸비는 약 15 dB, 3 dB 대역폭은 2 GHz, 그리고 Q값은 10이었다. 마이크로웨이브 필터에서 중심주파수의 출력특성을 27 dB범위 내에서 ${\sim}6.7dB/mW$로 조절할 수 있었다. 전기적으로 조절되는 전달특성을 갖는 이 필터는 마이크로웨이브스위치 등으로 응용할 수 있을 것으로 기대된다.