• 제목/요약/키워드: High mobility

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순차 증착한 InSb 박막의 전자 이동도 향상을 위한 대용융 재결정에 관한 연구 (A Study on the Zone Melting Recrystallization of Sequentially Evaporated InSb Thin Films for Improvement of the Electron Mobility)

  • 김병윤;현규택;주승기
    • 전자공학회논문지A
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    • 제30A권6호
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    • pp.31-37
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    • 1993
  • InSb thin films were fabricated by zone melting recrystallization of In/Sb multilayered thin films prepared by sequential evaporation. Unreacted metal phase or dispersed metal precipitates lowered the electron mobility and the electron mobility increased with development of (111) prefered orientation. Properties of the film could be controlled by changing mzximum temperature and scanning speed, and the electron mobility as high as 12, 000 cm $^2$/Vsec could be obtained under the optimized conditions.

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$0.1\;{\mu}m$ 이하의 게이트 길이를 갖는 Metamorphic High Electron Mobility Transistor의 모델링 및 구조 최적화 (Modeling and Optimization of $sub-0.1\;{\mu}m$ gate Metamorphic High Electron Mobility Transistors)

  • 한민;김삼동;이진구
    • 대한전자공학회논문지SD
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    • 제42권3호
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    • pp.1-8
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    • 2005
  • 본 논문에서는 $0.1\;{\mu}m$ 이하의 게이트 길이를 갖는 MHEMT의 DC 및 RF 특성을 상용 시뮬레이터인 ISE-TCAD tool을 이용하여 결과를 고찰하였다. 이후 MHEMT의 게이트 길이와, 소스-드레인 간격 및 채널 두께를 변화시켜 가면서 소자의 수평, 수직 Scaling효과가 소자 특성에 미치는 영향을 비교하였으며, 게이트 길이 $(L_g)$$0.1\;{\mu}m$ 이하로 감소함에 따라 $g_{m,max}$가 같이 감소하는 현상에 대해서 논의해 보았다. 또한 이 현상을 가지고 소자의 횡적, 종적 파라미터의 scaling 효과에 대한 모델을 제시 했다.

건축적 가구에 나타난 모빌리티(Mobility)의 구조적 의미 분석 - 안드레아 지텔의 작품을 중심으로 - (The Analysis of Structural Meaning of Mobility Design on Furnitecture - Focused on the Works of Andrea Zittel -)

  • 김은정;김미경
    • 한국실내디자인학회논문집
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    • 제23권4호
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    • pp.42-51
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    • 2014
  • The research aims to analyze the structural meaning of mobility design on 'Furnitecture' with the works of Andrea Zittel. The study consists of the literature review and the analysis of Zittel's works. The framework for the analysis is divided into four steps: identification of visual forms/structure/function, analysis of the principles of delivering the concept of mobility, interpretation & synthesis of the relational meanings derived from the concepts of mobility, and evaluation of Zittel's tendency toward design/social background/design history, etc. Total fifteen cases are selected from Zittel's works, and each case is analyzed following the above steps. The finding shows that Zittel likes to play with geometrical forms, grid & modular system to create a minimum space for living equipped with critical furnishing. Secondly, Zittel's works deliver the concept of mobility by applying movability, adaptation, combination and transformation. Thirdly, through the concepts of mobility, Zittel reflects the ideas of high efficiency and functionalism, harmony with natural environment, search for liberty, simple & humble life and success of the designers of American modernism. Finally, it is found that modernism from the era of Bauhaus, utopian values derived from constructionism, utilitarianism inspired by Shakers and homestead act & mobile home/capsule unit suggested since 19th century in America mainly affect Zittel's works to reflect the dynamic concepts of mobility through the design of furnitecture.

Effect of Double Schottky Barrier in Gallium-Zinc-Oxide Thin Film

  • Oh, Teresa
    • Transactions on Electrical and Electronic Materials
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    • 제18권6호
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    • pp.323-329
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    • 2017
  • This reports the electrical behavior, bonding structure and Schottky contact of gallium-zinc-oxide (GZO) thin film annealed at $100{\sim}400^{\circ}C$. The mobility of GZO with high density of PL spectra and crystal structure was also increased because of the structural matching between GZO and Si substrate of a crystal structure. However, the GZO annealed at $200^{\circ}C$ with an amorphous structure had the highest mobility as a result of a band to band tunneling effect. The mobility of GZO treated at low annealing temperatures under $200^{\circ}C$ increased at the GZO with an amorphous structure, but that at high temperatures over $200^{\circ}C$ also increased when it was the GZO of a crystal structure. The mobility of GZO with a Schottky barrier (SB) was mostly increased because of the effect of surface currents as well as the additional internal potential difference.

MHEMT 소자의 DC/RF 특성에 대한 시뮬레이션 연구 (Simulation Study on the DC/RF Characteristics of MHEMTs)

  • 손명식
    • 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.

액체 수소 BOG 안전 압력 유지 및 제어를 위한 극저온 용기의 수치 해석 모델 개발 (Development of Numerical Analysis Model on Cryogenic Vessel for Safety Pressure Maintenance and Control of Liquid Hydrogen BOG)

  • 서영민;노현우;구태형;하동우;고락길
    • 한국수소및신에너지학회논문집
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    • 제35권3호
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    • pp.280-289
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    • 2024
  • In this study, a cryogenic vessel was constructed to maintain and control the safe pressure of liquid hydrogen boil-off gas (BOG), and the numerical analysis was conducted on the development of computational fluid dynamics model inside the high-pressure vessel. An evaluation system was constructed using cryogenic inner and outer containers, pre-cooler, upper flange, and internal high-pressure container. We attempted to analyze the performance of the safety valve by injecting relatively high temperature hydrogen gas to generate BOG gas and quickly control the pressure of the high-pressure vessel up to 10 bar. As a results, the liquid volume fraction decreased with a rapid evaporation, and the pressure distribution increased monotonically inside a high pressure vessel. Additionally, it was found that the time to reach 10 bar was greatly affected by the filling rate of liquid hydrogen.

Proxy Mobile IPv6 환경에서 동적 페이징 지원을 위한 이동성 관리기법 (A New Mobility Management Scheme in Proxy Mobile IPv6 Networks with Dynamic Paging Support)

  • 이명규;김철중;박석천;양영규
    • 한국정보통신학회논문지
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    • 제14권9호
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    • pp.1999-2007
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    • 2010
  • Proxy Mobile IPv6(PMIPv6)는 이동 노드에게 이동성 관리 기능을 요구하지 않는 네트워크 기반의 이동성 관리 프로토콜이다. PMIPv6에서 Mobile Access Gateway(MAG)는 이동노드가 이동 할 때마다 원거리에 위치한 Local Mobility Anchor(LMA)에 위치등록을 수행해야 하며, 이러한 위치등록은 네트워크의 과도한 트래픽과 LMA 부하를 증가시키는 원인이 된다. 따라서, 본 논문에서는 PMIPv6 환경에서 동적 페이징 지원을 위한 이동성 관리기법을 제안하였다. 제안기법에서는 위치등록비용을 감소하기 위해서 페이징 기법을 적용하였으며, 페이징 영역의 크기는 이동노드의 이동 및 통신 패턴에 따라 동적으로 조정된다. 제안기법의 성능을 분석하기 위하여 유체유동(fluid flow) 모델을 이용한 비용 계산식을 구하였으며, 수학적인 비용 분석 결과를 통하여 제안기법이 PMIPv6보다 우수한 성능을 제공함을 알 수 있다.

중앙119구조본부 소방대원용 화학 보호복과 방열복의 동작적합성 평가 및 디자인 개선 (Enhancing Design and Evaluating Mobility of Firefighting Chemical and Flame Protective Clothing for the National 119 Rescue Headquarters)

  • ;김도희;이주영
    • 한국의류산업학회지
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    • 제25권4호
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    • pp.520-533
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    • 2023
  • The present study developed a test protocol for evaluating the mobility of firefighting chemical and flame personal protective equipment (PPE) for the National 119 Rescue Headquarters in Korea and suggested ergonomic design factors to improve their mobility and performance. Six types of PPE were employed, including three types for flame protective PPE (5 ~ 6 kg excluding the self-contained breathing apparatus), and three types for chemical and flame protective PPE (8 ~ 11 kg). These PPEs are used by the 119 Rescue firefighters. Three male firefighters (34.3 ± 1.2 y in age, 175 ± 8 cm in height, 81 ± 13 kg in body weight) participated in the mobility test and interview. A mobility test protocol consisting of 16 components (nine postures and seven motions including a dexterity test) along with a visibility test were developed based on pre-interviews and literature reviews. The findings indicated that the clothing microclimate humidity on the neck and chest exceeded 85%RH on average for all the six PPE conditions, with the chest area reaching as high as 98%RH. This high humidity caused fogging inside the visor and impaired visibility. The requirements for improving the PPE design in terms of mobility varied depending on whether it was the separated types or all-in-one types, particularly regarding the hood and gloves design. The findings of this study can be applied to improve the design of Level A_PPE for firefighters. The mobility test protocol and visibility test developed in this study can also be applied to other types of Level A impermeable PPE.

A Mobility Control Architecture Suppor ting Fast Handover for Future Internet Networks

  • Nguyen, Khanh-Huy;Hwang, Won-Joo
    • 한국멀티미디어학회논문지
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    • 제15권12호
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    • pp.1485-1491
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    • 2012
  • In this paper, we address the problem of fast handover support for future internet networks. The current mobility support protocols, for example Proxy Mobile IPv6, follow a centralized architecture in which a mobility controller is used to manage intra-network handovers that gives rise to high handover latency. To handle this problem, we propose a novel distributed mobility control architecture in which gateways in the network can exchange user information with neighbour gateways to support intra-network handovers, the mobility controller is only needed in case of inter-network handovers. Simulation results show that our architecture reduce approximately 20% intra-network handover latency than Proxy Mobile IPv6.