• 제목/요약/키워드: mobility pattern

검색결과 311건 처리시간 0.022초

RF-MBE 성장조건에 따른 InGaN 단결정 박막의 결정성 관찰 (Effect of Growth Conditions on Crystal Quality of InGaN Epitaxial Layers Grown by RF-MBE)

  • 나현석
    • 열처리공학회지
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    • 제31권5호
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    • pp.237-243
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    • 2018
  • In-rich InGaN epilayers were grown on (0001) sapphire substrates by radio-frequency plasma-assisted molecular beam epitaxy (RF-MBE). InGaN epilayers grown at various growth condition were observed by SEM, XRD, and RHEED. When plasma power of nitrogen increased from 290 to 350 W, surface morphology and crystal quality became worse according to more active nitrogen on the surface of InGaN at N-rich growth condition. As In composition was reduced from 89 to 71% by changing the incoming flux of In and Ga, surface morphology and crystal quality became worse. In addition, weak peaks of cubic InGaN phase was observed from InGaN layer with 71% In composition by XRD ${\Phi}$ scan measurement. When growth temperature decreased from 500 to $400^{\circ}C$, RHEED diffraction pattern was changed to be from streaky to spotty which means atomically rough surface, and spotty pattern showed cubic symmetry of InGaN clearly. XRD ${\Phi}$ scan measurement gave clear evidence that more cubic InGaN phase was formed at low growth temperature. All these results indicates that extremely low surface mobility of Ga adatom caused inferior crystal quality and cubic InGaN phase.

한국의 세대 간 경제적 이동성 - 분위수회귀분석을 중심으로 - (Intergenerational economic mobility in Korea using a quantile regression analysis)

  • ;정기호
    • Journal of the Korean Data and Information Science Society
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    • 제25권4호
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    • pp.715-725
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    • 2014
  • 본 연구는 분위수회귀분석을 이용하여 한국의 세대 간 경제적 이동성을 분석한다. 분석에는 1998년부터 2008년까지의 한국노동패널조사 (KLIPS) 자료가 이용되었다. 분석결과, (1) 부모 소득영향력은 자녀소득의 조건부분포의 하위 분위수에서는 상대적으로 작고 상위 분위수로 갈수록 더 커지는 것으로 나타났다. 이것은 자녀소득 분포의 상위분위수로 갈수록 세대 간 경제적 이동성은 떨어지며 가구별 경제적 신분이 세대에 걸쳐 고착될 가능성이 높아지는 것을 의미한다. (2) 한편 교육효과를 제어하면 이러한 부모 소득 영향력은 감소하였다. (3) 대학교육 효과는 소득분포의 상위 분위수로 갈수록 더 높아져서 자녀의 대학교육이 세대 간에 소득이 이전되는 중요한 통로인 것으로 나타났다. (4) 마지막으로 분위수회귀분석결과로부터 자녀소득의 조건부분포를 비모수적으로 추정하고 추정된 곡선 그림을 이용하여 추가적인 시각적 특징들을 도출하였다.

아동용 스키 팬츠의 기능적 설계요소 연구 (A Study on the Functional Design Elements for Children's Ski Pants)

  • 김경옥;천종숙
    • 한국의류산업학회지
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    • 제25권2호
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    • pp.199-209
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    • 2023
  • This study identified design elements of the functions required for children's ski pants. Data for this study were collected through questionnaire surveys conducted among children's ski instructors and children's sportswear developers. Five functionalities of children's skiwear were evaluated: mobility, stability, comfort, protection, and convenience. A total of 25 functional design elements related to the patterns, design details, and physical characteristics of fabrics for ski garments, were evaluated. The results of this study are as follows. First, children's sportswear developers evaluated that the pattern elements were important. Most of the pattern design elements highly related to mobility. Children's ski instructors' appraisal was that the height of the back waist was the important feature. Second, regarding the design details, children's ski instructors evaluated the size adjustment function and ventilation system as important elements. Many design detail elements were highly related in respect of stability, comfort, protection, and convenience. Third, the physical characteristics of fabric were strongly associated with mobility, comfort, and protection. As regards the physical characteristics of fabric, children's ski instructors valued anti-fouling highly, but children's sportswear developers attached more importance to the weight of the fabric. The results of this study will be useful in designing functional ski pants for children of elementary and intermediate ski levels. Since there may be limitations related to the ski level and age of children wearing ski pants, it is suggested that follow-up studies according to various groups of the ski pant wearers should be done.

기모노슬리브 원형 개발 - 30대 표준체형을 중심으로 - (Development of a basic kimono sleeve - Focusing on the standard body type of Korean people in their thirties -)

  • 권순교;어미경
    • 복식문화연구
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    • 제25권2호
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    • pp.224-236
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    • 2017
  • Kimono sleeves have continuously appeared in modern fashion as a design motif and this trend has become increasingly prevalent recently. However for research in the area of clothing composition for kimono sleeves in Korea, there has been a lack of development of master patterns based on basic data from the analysis of the standard body type of Korean people and finalized designs based on comparative experiments and analysis of pre-existing research Thus, there is no ideal master kimono sleeve pattern development research based on the examination of the results of the analysis of the standard body type of Korean people. Therefore by recognizing the importance of developing a master kimono sleeve pattern, this research aims to present a practical master kimono sleeve pattern for the standard body type of someone in their 30s. First, the four master patterns were collected and a dressing evaluation was conducted, and by selecting and improving one of these master designs, a final research master pattern was developed after a second dressing evaluation. Through this research, it was possible to design a master kimono sleeve pattern appropriate both externally and functionally for the standard body type of someone in their 30s, which has not been a consideration in previous research.

문양 이미지에 관한 연구[ 1 ] -문양 이미지 포지셔닝 기준 개발을 중심으로- (A Study on Image of Patterns [ 1 ] - With a focus on Development on Image Positioning of Patterns -)

  • 유현정;김민자
    • 복식
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    • 제59권2호
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    • pp.29-41
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    • 2009
  • Perception between real object and recognized subject of human on objective subject is not the same. The reason Is that individual perception of visual design components are transmitted as the image of whole. It is required process of visual perception. Therefore, I developed the vision of seeing image of pattern which is based on Gestalt visual perception theory in clothes. The summary of this study's results is like followings. Extremely antagonistic terms which are specialized by formative characteristics of formative components are clearness and blur of outline/ fixed shape and non-fixed shape/ visuality and tangibility of representation/ simplicity and complexity of structure/ invariability and variability of mobility/ symmetry and asymmetry of arrangements singularity and plurality of group number. The expression of motive shows that clearness, fixed shape, visuality and simplicity pursuit Determination image, and blur, non-fixed shape, tangibility and complexity pursuit Ambiguity image. The arrangements of motive shows that invariability, symmetry and singularity pursuit Order image, and variability asymmetry and plurality pursuit Disorder image. Therefore, the standard of the coordinator of Pattern image positioning is established as Determination and Ambiguity of motive are X-axis, and Order and Disorder of pattern are Y-axis. As the frame of Pattern image positioning, four separated dimensions have made.

Degradation Pattern of Black phosphorus Field Effect Transistor

  • 이병철;주민규;진준언;이재우;김규태
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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    • pp.120.1-120.1
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    • 2015
  • We investigate the degradation pattern of Black phosphorus (BP) field effect transistor (FETs) investigated by using an mechanically exfoliated BP that react O2 and water vapor in ambient condition, degradation. The BP FETs was electrically measured every 20 minutes (1cycle) in the air, the total cycle is 100. We show electrical changes with Mobility, On/off ratio, Current and a significant positive shift in the threshold voltage. We extracted the current level at Vgs-Vth = 0, -10, -20 and fitting with Swiss-cheese model. This model suggested that Swiss-cheese model is well fitted with degradation pattern of BP FETs.

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Mobility Prediction Algorithms Using User Traces in Wireless Networks

  • Luong, Chuyen;Do, Son;Park, Hyukro;Choi, Deokjai
    • 한국멀티미디어학회논문지
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    • 제17권8호
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    • pp.946-952
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    • 2014
  • Mobility prediction is one of hot topics using location history information. It is useful for not only user-level applications such as people finder and recommendation sharing service but also for system-level applications such as hand-off management, resource allocation, and quality of service of wireless services. Most of current prediction techniques often use a set of significant locations without taking into account possible location information changes for prediction. Markov-based, LZ-based and Prediction by Pattern Matching techniques consider interesting locations to enhance the prediction accuracy, but they do not consider interesting location changes. In our paper, we propose an algorithm which integrates the changing or emerging new location information. This approach is based on Active LeZi algorithm, but both of new location and all possible location contexts will be updated in the tree with the fixed depth. Furthermore, the tree will also be updated even when there is no new location detected but the expected route is changed. We find that our algorithm is adaptive to predict next location. We evaluate our proposed system on a part of Dartmouth dataset consisting of 1026 users. An accuracy rate of more than 84% is achieved.

EEDARS: An Energy-Efficient Dual-Sink Algorithm with Role Switching Mechanism for Event-Driven Wireless Sensor Networks

  • Eslaminejad, Mohammadreza;Razak, Shukor Abd;Ismail, Abdul Samad Haji
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제6권10호
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    • pp.2473-2492
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    • 2012
  • Energy conservation is a vital issue in wireless sensor networks. Recently, employing mobile sinks for data gathering become a pervasive trend to deal with this problem. The sink can follow stochastic or pre-defined paths; however the controlled mobility pattern nowadays is taken more into consideration. In this method, the sink moves across the network autonomously and changes its position based on the energy factors. Although the sink mobility would reduce nodes' energy consumption and enhance the network lifetime, the overhead caused by topological changes could waste unnecessary power through the sensor field. In this paper, we proposed EEDARS, an energy-efficient dual-sink algorithm with role switching mechanism which utilizes both static and mobile sinks. The static sink is engaged to avoid any periodic flooding for sink localization, while the mobile sink adaptively moves towards the event region for data collection. Furthermore, a role switching mechanism is applied to the protocol in order to send the nearest sink to the recent event area, hence shorten the path. This algorithm could be employed in event-driven and multi-hop scenarios. Analytical model and extensive simulation results for EEDARS demonstrate a significant improvement on the network metrics especially the lifetime, the load and the end-to-end delay.

스마트 플레이스 부하모델 개발을 위한 이동성 부하 및 보급패턴에 관한 연구 (A Study on Mobility Loads and the Deployment Patterns for the Development of Smart Place Load Model)

  • 황성욱;송일근;김정훈
    • 전기학회논문지
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    • 제63권2호
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    • pp.217-223
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    • 2014
  • Recently, various researches and projects about electric vehicles are in progress vigorously and continuously and it is expected to penetrate rapidly with the next a few years. This deployment will cause the change of load composition rate affecting on power system planning and operations. Therefore, a new load model should be developed integrating with electric vehicle loads. In this paper, the load composition rate of residential sectors is analyzed considering the deployment of this mobility load such as electric vehicles and a new diffusion model is proposed based on the classification of the replacement patterns. Additionally, electric vehicle charging loads are basically modeled by some individual load experiments to develop new load models for smart place and some new conceptual power systems such as micro grids.

셀룰러 망에서 프로파일 기반 위치관리를 위한 위치영역 리스트 생성 (Location Area List Generation for Profile Based Location Management in Cellular Networks)

  • 조현준
    • 컴퓨터교육학회논문지
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    • 제8권6호
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    • pp.123-132
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    • 2005
  • 이동망의 위치관리에서 위치갱신 비용 최소화를 위한 많은 연구 결과들이 있다. 위치갱신 비용의 최소화를 위해서는 각 사용자들의 이동 패턴을 고려해야만 한다. 본 논문은 과거의 사용자 이동에 대한 이력으로부터 각 사용자에 대한 위치영역 리스트 생성과 이를 위한 3 단계 페이징 방안을 제안한다. 사용자의 이동은 공간적으로 뿐만 아니라 시간적으로도 규칙적인 패턴이 존재한다. 따라서 제안된 위치영역 리스트 생성방안은 이상의 2가지 측면에서 사용자의 방문빈도를 이용하여 규칙성을 발견하고, 이에 대한 위치영역리스트를 생성한다. 제안된 방안의 성능분석 위해서 제안된 방안에 대하여 사용자 이동 패턴을 고려한 모의실험을 수행하였다. 모의실험 결과 제안된 방안이 위치관리 비용 측면에서 장점이 있음이 확인되었다.

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