• 한국산업융합학회 논문집
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• 제24권6_2호
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• pp.919-926
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• 2021

In this paper, a study was conducted on the miniaturization of an e-Mobility battery charger module using GaN-FET. GaN-FET is one of the types of WBG devices, and it is a device that exceeds the performance of existing Si power semiconductors. In particular, GaN-FET has the advantage of small packaging size and high switching frequency operation, which is advantageous for miniaturization of power converters. Therefore, a bidirectional DC/DC converter module for e-mobility charging using GaN-FET was developed. To apply to the converter to be developed, analysis is performed on the characteristics of GaN-FET, and after manufacturing a prototype of a bidirectional DC/DC converter module, the efficiency and temperature data of the power converter are analyzed to verify its feasibility.

• KIEE International Transactions on Electrophysics and Applications
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• 제4C권2호
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• pp.39-44
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• 2004

The present paper gives a review of the recent development of a differential mobility analyzer (DMA) available for both particle size measurements and production of monodisperse particles in the nanometer range. Operating principles of a general DMA are introduced as well as characteristics of highly functional DMAs such as those capable of classifying particles in a measurement range as broad as 1-1000nm at low pressures. Some examples of DMA applications are also described.

• 한국콘텐츠학회논문지
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• 제19권10호
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• pp.568-580
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• 2019

MaaS의 영향력이 주목받고 있는 가운데, 공유 모빌리티를 중심으로 모빌리티 서비스 시장이 급격히 성장하고 있다. 시장 선점을 위해서 현재 초기 확산단계에 있는 퍼스널 모빌리티 서비스 이용자의 인식과 경험을 파악하고, 향후 확장될 시장의 잠재 소비자들의 특성을 이해하는 것이 중요하다. 따라서 이 연구는 주관성 연구방법인 Q 방법론을 사용하여 퍼스널 모빌리티 이용자 유형을 분류하고 UX(User experience) 전략을 수립하고자 하였다. 제품 및 서비스 특성과 이용자의 개인적 특성 요소들을 중심으로 41개 구성하고, 잠재 사용자와 실사용자를 포함하는 30명의 P샘플을 대상으로 데이터를 수집하였다. QUANL 소프트웨어를 사용하여 수집한 데이터를 분석하였으며, 그 결과 (1)효율적인 이동 우선형(Mobility Efficiency), (2)경계하는 안전추구형(Safety First), (3)합리적인 여가활용형(Rational Utilization), (4)호기심 많은 재미추구형(Sheer Riding Pleasure)의 네 가지 심성 모형이 도출되었다.

• 한국게임학회 논문지
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• 제10권6호
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• pp.57-65
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• 2010

본 논문에서는 6자유도를 갖는 병렬형 기구의 출력 속도 공간에서 성능을 평가할 수 있는 지표를 제안하였다. Manipulability와 condition number에 기반을 둔 성능 지표가 단위계의 볼일치로 인한 물리적 의미의 결함이 없도록 출력공간을 병진속도 공간과 회전속도 공간으로 분리하는 방법을 제안하였다. 각 공간에서 단위 입력에 대용하는 mobility ellipsoid를 정의하여 이를 기반으로 병진운동 출력공간에서 두 종류 성능 지표와 회전운동 공간에서 두 종류의 성능 지표를 제안하였다.

• 한국실내디자인학회논문집
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• 제24권4호
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• pp.99-110
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• 2015

The purpose of this study is to identify pre-elderly's housing mobility related characteristics (reasons for moving, change of personal life after move, housing attachment, and plan to future move) and to examine the associations between their socio-demographic characteristics and housing characteristics, and their housing mobility related characteristics. A total of 200 usable data were collected through personal survey using a questionnaire developed by the researcher. Samples were selected in Seoul and new towns in the capital area and a survey conducted from February, 2014 to December, 2014. For the analyses, descriptive statistics, factor analysis, t-test and ANOVA were used. The most frequently mentioned reasons for moving were 'a good place for nature and retirement life'. Age, education level, liiving expenses, locaion, tenure status, and housing size were the variables to show significant difference to reasons for moving. Respondents experienced positive personal life changes after moving, especially, 'physical health' and outgoing activity'. Respondents who moved to a new town was more positively changed. Personal life changes was the most important variable associated with 3 factors of housing attachment. Location, tenure status, housing size were the major variables to show differences to housing attaachment. Also, personal life changes after moving and housing attachment were the important variables affecting a plan to future move. In other words, the respondents who do not plan to future move showed higher positive life change and strong housing attachment.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권4호
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• pp.161-168
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• 2001

Organic thin film transitors(TFTs) are of interest for use in broad area electronic applications. For example, in active matrix liquid crystal displays(AMLCDs), organic TFTs would allow the use of inexpensive, light-weight, flexible, and mechanically rugged plastic substrates as an alternative to the glass substrates needed for commonly used hydrogenated amorphous silicon(a-Si:H). Recently pentacene TFTs with carrier field effect, mobility as large as 2 $cm^2V^{-1}s^{-1}$ have been reported for TFTs fabricated on silicon substrates, and it is higher than that of a-Si:H. But these TFTs are fabricated on silicon wafer and $SiO_2$ was used as a gate insulator. $SiO_2$ deposition process requires a high insulator which is polyimide and photo acryl. We investigated trasfer and output characteristics of the thin film transistors having active layer of pentacene. We calculated field effect mobility and on/off ratio from transfer characteristics of pentacene thin film transistor, and measured IR absorption spectrum of polymide used as the gate dielectric layer. It was found that using the photo acryl as a gate insulator, threshold voltage decreased from -12.5 V to -7 V, field effect mobility increased from 0.012 $cm^2V^{-1}s^{-1}$ to 0.039 $cm^2V^{-1}s^{-1}$ , and on/off current ratio increased from $10^5\;to\;10^6$. It seems that TFTs using photo acryl gate insulator is apt to form channel than TFTs using polyimide gate insulator.

• 한국진공학회지
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• 제20권5호
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• pp.345-355
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• 2011

GaAs나 InP 기반의 high electron mobility transistor (HEMT) 소자들은 우수한 마이크로파 및 밀리미터파 주파수 특성 및 이에 따른 우수한 저잡음 특성을 가지고 있다. GaAs 기판 위에 점진적으로 성장된 메타몰픽(Metamorphic) HEMTs (MHEMTs)는 InP 기판 위에 성정한 HEMT에 비해 비용 측면에서 커다란 장점을 가지고 있다. 본 논문에서는 이러한 MHEMT의 DC/RF 소신호 특성을 예측하기 위하여 InAlAs/InGaAs/GaAs MHEMT 소자들의 DC/RF 소신호 주파수 특성을 시뮬레이션하였다. 2차원 소자 시뮬레이터의 hydrodynamic 전송 모델을 사용하여 $In_{0.52}Al_{0.48}As/In_{0.53}Ga_{0.47}As$ 이종접합 구조를 갖는 제작된 0.1-${\mu}m$ ${\Gamma}$-게이트 MHEMT 소자에 대하여 파라미터 보정 작업을 수행한 후, MHEMT 소자들에 대해 DC 특성 및 RF 소신호 주파수 특성을 시뮬레이션하고 실험 데이터와 비교 분석하였다. 또한, 게이트 리세스 구조에 따른 MHEMT 소자들의 DC/RF 특성을 시뮬레이션하고 비교 분석하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.81-84
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• 2004

Required characteristics of poly-Si TFT's are investigated for the implementation of analog circuits to be integrated on System-on-Glass (SoG). Matching requirements on resistor values, threshold voltage and mobility of poly-Si TFT's are derived as a function of the resolution of display system. Effective mobility of poly-Si TFT's required for the realization of source driver is analyzed for various panel sizes.

• Journal of Information Display
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• 제5권4호
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• pp.1-6
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• 2004

In this paper, we investigate on the characteristics of poly-Si TFTs reuired for the implementation of analog circuits to be integrated with System-on-Glass (SoG). Matching requirements in terms of resistor values, threshold voltage and mobility of poly-Si TFTs are derived as a function of the resolution of display system. Effective mobility of poly-Si TFTs required for the realization of source driver is analyzed for various panel sizes.

• Transactions on Electrical and Electronic Materials
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• 제12권4호
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• pp.148-151
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• 2011

We designed and fabricated aluminium gallium nitride (AlGaN)/GaN high electron mobility transistors (HEMTs) with stable reverse blocking characteristics established by employing a selective fluoride plasma treatment on the drainside gate edge region where the electric field is concentrated. Implanted fluoride ions caused a depolarization in the AlGaN layer and introduced an extra depletion region. The overall contour of the depletion region was expanded along the drift region. The expanded depletion region distributed the field more uniformly and reduced the field intensity peak. Through this field modulation, the leakage current was reduced to 9.3 nA and the breakdown voltage ($V_{BR}$) improved from 900 V to 1,400 V.