• 제목/요약/키워드: 반동

검색결과 111건 처리시간 0.032초

태권도 돌려차기 시 분절들의 반동동작 (Countermovement of the Segments During the Tae-kwon-do Roundhouse Kicking)

  • 황인승;이성철;임정
    • 한국운동역학회지
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    • 제14권2호
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    • pp.139-152
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    • 2004
  • Two subjects, an expert and a novice, were carefully selected based upon their foot speed. Three dimensional videography was used in the assessment of roundhouse kicking of the Tae-kwon-Do. The local reference frames were imbedded at the trunk, pelvis, thigh and shank. Anatomical angular displacement at the joints were measured by projecting the upper segment's local axes to the lower segment's local reference planes. The local axes again projected to the global reference frames and absolved each segment's movement. The peaks of the anatomical angular displacement curve assessed as the countermovements and the angular movements of the segments in the global space absolved in light of the occurrence of the countermovements. The expert showed larger and more countermovements than the novice at the all segments. The counterrnovement occured more clearly at the trunk than the hip and knee joint and during the preparative movement phase. These countermovements occurrence were due to either by turning upper or lower segments and controlled by the turning direction and sequence of the two nearby segments. It was revealed that the countermovements of the trunk during the preparative movement phase was the important factor of the power kicking.

클러스터 이기종 셀룰러 네트워크를 위한 합동 셀 그룹핑 및 사용자 접속 기법 (Joint Cell Grouping and User Association Scheme for Clustered Heterogeneous Cellular Networks)

  • 박진배;이형열;최우리;김광순
    • 한국통신학회논문지
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    • 제38A권6호
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    • pp.520-527
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    • 2013
  • 본 논문에서는 클러스터 이기종 셀룰러 네트워크에서 반동적 셀 그룹핑을 위한 합동 셀 그룹핑 및 사용자 접속 기법을 제안한다. 최근에는 핫스팟에서의 폭발적인 데이터 요구량을 지원하기 위해서, 소형 셀들이 기존의 매크로 기지국들과 함께 설치되고 있다. 이러한 클러스터 이기종 셀룰러 네트워크에서는 간섭과 부하 불균형으로 인하여 성능 열화가 발생할 수 있다. 본 논문에서 제안하는 기법은 사용자들의 비례공평이 최대화되도록 두 가지 문제를 합동적으로 다룬다. 모의실험을 통하여, 기존의 기법들보다 제안하는 기법을 통해 훨씬 더 향상된 사용자 평균 전송률 및 사용자간의 비례공평을 얻을 수 있음을 알아본다.

MoS2 기반의 쇼트키 반도체 광전소자 (MoS2-Embedded Schottky Photoelectric Devices)

  • 반동균;박왕희;정복만;김준동
    • 한국전기전자재료학회논문지
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    • 제30권7호
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    • pp.417-422
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    • 2017
  • A high-performing photoelectric device was realized for the $MoS_2$-embedded Si device. $MoS_2$-coating was performed by an available large-scale sputtering method. The $MoS_2$-layer coating on the p-Si spontaneously provides the rectifying current flow with a significant rectifying ratio of 617. Moreover, the highly optical transmittance of the $MoS_2$-layer provides over 80% transmittance for broad wavelengths. The $MoS_2$-embedded Si photodetector shows the sensitive photo-response for middle and long-wavelength photons due to the functional $MoS_2$-layer, which resolves the conventional limit of Si for long wavelength detection. The functional design of $MoS_2$-layer would provide a promising route for enhanced photoelectric devices, including photovoltaic cells and photodetectors.

퍼지 제어 알고리즘을 이용한 차량 조향 장치용 표면 부착형 영구자석 동기 전동기의 속도제어 (Speed Control of a Permanent Magnet Synchronous Motor for Steering System Using Fuzzy Algorithm)

  • 반동훈;박종오;임영도
    • 제어로봇시스템학회논문지
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    • 제18권6호
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    • pp.526-531
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    • 2012
  • This paper, we describe the vector control of surface mounted PMSM (Permanent Magnet Synchronous Motor) using the fuzzy controller which is suggested algorithm. In these days, when vehicle is operated or not, whether the road is covered or not, the sensitivity of the steering column is not stable. To make up for it, the PI gain of a steering column controller is adjusted by experience. It becomes the price because it need a lot of sensor. Also it is difficult to implement robust control because we need a lot of parameters for variable road conditions which are the off road, the on road, a low battery voltage, a high battery voltage, a vehicle speed. In this paper, we propose fuzzy controller using the suggested algorithm which suitable for steering system. We test the fuzzy controller with the various condition. We get the good performance of fuzzy controller even if it is nonlinear system. We check a robust the fuzzy controller using the suggested algorithm.

SnS 기반의 고성능 투명 UV 광검출기 (SnS-embedded High Performing and Transparent UV Photodetector)

  • 박왕희;반동균;김현기;김홍식;;유정희;김준동
    • 한국전기전자재료학회논문지
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    • 제29권7호
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    • pp.445-448
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    • 2016
  • Transparent UV photodetector was achieved by using wide bandgap metal oxide materials. In order to realize transparent heterojunction UV photodetector, n-type ZnO and p-type NiO metal oxide materials were employed. High light-absorbing SnS layer was inserted into the n-ZnO and p-NiO layers. High-performing UV photodetector was realized by ZnO/SnS/NiO/ITO structures to provide extremely fast response times (Fall time: $7{\mu}s$ and rise time: $13{\mu}s$) and high rectifying ratio. The use of functional SnS-embedded photodetector would provide a route for high functional photoelectric devices.

창조적 디자인 발상을 위한 디자인방법론 (Design Methodology for Creative Design Thinking)

  • 홍정표;정수경
    • 감성과학
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    • 제9권4호
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    • pp.385-394
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    • 2006
  • 미학적인 디자인이 상품가치를 갖게 될 현재 사회에서 디자인은 기존의 개념을 탈피하고 파괴하는 반동의 에너지와 부드럽고 유연한 감성을 불어넣는 것이어야 한다. 이러한 디자인 목표에 이르기 위한 '창조적 발상'은 디자이너가 갖추어야 할 가장 중요한 능력 중의 하나이며, 형태적 접근이나 이미지 개발은 물론 기능이나 성능 등 상품 컨셉(Concept)까지 관여하는 디자인 문제해결에 있어서의 총체적인 개념이다. 본 연구에서는 창조성의 정의, 디자인의 환경변화와 그에 따른 디자이너가 갖추어야 할 조건, 선행연구 된 창조적 디자인 발상법 등을 살펴보고 휴대폰을 대상으로 창조적 디자인 사고를 위한 디자인 방법을 제시함으로써 창조성의 중요성과 디자이너의 창조적 가치 향상에 기여하고자 한다.

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고온 열판에 충돌하는 액적의 거동에 대한 유동가시화 연구 (A Visualization Study on the Characteristics of Droplets Impinging on a Hot Surface)

  • 김동연;이승재;김경천
    • 한국가시화정보학회지
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    • 제10권1호
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    • pp.21-26
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    • 2012
  • Hydrophobic characteristics of high temperature metal surface were investigated by high-speed visualization of water droplet impact. An aluminum plate was used as the sample plate and the initial diameter of a water droplet was 2 mm. Transient behavior of a single droplet impinging on the surface with and without heating was captured by using a high speed camera running at 4,000 frames per second. The Leidenfrost phenomenon was demonstrated for the case of $300^{\circ}C$ surface temperature, however there was no rebounding of droplet on the cold plate due to hydrophilic nature. The experimental results show that the shape evolution of a droplet impinging on the surface varies with the Weber number, i.e. the ratio of impact inertia to capillary force. The overall water-repellent characteristics of the heated surface was very similar to that of the super hydrophobic surfaces.

NiO 기반의 투명 금속 산화물 반도체 광전소자 (NiO-transparent Metal-oxide Semiconductor Photoelectric Devices)

  • 반동균;박왕희;은승완;김준동
    • 한국전기전자재료학회논문지
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    • 제29권6호
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    • pp.359-364
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    • 2016
  • NiO serves as a window layer for Si photoelectric devices. Due to the wide energy bandgap of NiO, high optical transparency (over 80%) was achieved and applied for Si photoelectric devices. Due to the high the high mobility, the heterojunction device (Al/n-Si/$SiO_2$/p-NiO/ITO) provide ultimately fast photoresponses of rising time of $38.33{\mu}s$ and falling time of $39.25{\mu}s$, respectively. This functional NiO layer would provide benefits for high-performing photoelectric devices, including photodetectors and solar cells.

소형 프로펠러 단독시험기 설계 (A Design Experience of Propeller Open Water Testing Dynamometer)

  • 김재성;송무석;김효철
    • 대한조선학회논문집
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    • 제32권4호
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    • pp.48-54
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    • 1995
  • 선박용 추진기의 단독시험을 위한 소형시험기를 설계제작하고 모형선 예인수조에서 검증시험을 실시하였다. 제작된 시험기는 전동기의 반동력을 스트레인 게이지를 이용하여 직접 계측함으로써 재래의 시험기에서 사용하고 있는 마모성 슬립링을(Slip Ring) 제거하였다. 또한 기기의 구조 부재를 검력계의 검출부로 사용함으로써 소형의 모형선에 탑재될 수 있도록 경량화 및 소형화를 이룩하였다. 개발된 이 제품은 회류수조 등에서 효과적으로 사용될 수 있을 뿐만 아니라 선형시험수조 및 캐비테이션 터널에서 사용될 각종 시험 기기 설계의 기초기술을 포괄하는 것으로 평가된다.

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스테로이드제 중단 이후 반동 현상이 발생한 아토피 피부염의 치험 2례 (Two Case Reports on Atopic Dermatitis with Rebound Phenomena after Steroid Interruption)

  • 조수지;김철윤;하우람;권강
    • 한방안이비인후피부과학회지
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    • 제34권1호
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    • pp.101-111
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    • 2021
  • Objectives : Steroids are often administered to atopic patients as hormone preparations, often causing side effects. This study is intended to present the possibility of Korean medicine treatment for patients who have had side effects due to steroids in atopic dermatitis by relieving side effects and improving symptoms through Korean medicine such as Hwangryounhaedok-tang and Siryeong-tang. Methods : 2 patients who had atopic dermatitis and rebound phenomenon after steroids treatment were treated by herbal medicine, herbal acupuncture, acupuncture and external preparations. Photographs of the lesions, SCORAD(Scoring atopic dermatitis) index were used to evaluate the changes in symptoms. Results : The SCORAD index of the first patient improved from 55.6 to 24.3 in 4 months. The SCORAD index of the second patient improved from 44.7 to 21.3 in 3 months. Conclusions : In the situation where symptoms of atopic dermatitis patients due to steroid rebound phenomenon have worsened, Korean medicine treatments played a important role in alleviating symptoms and improving SCORAD index scores.