• 제목/요약/키워드: disturbance system

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3-블레이드 회전익 항공기에서 기하학적 정밀 보의 공탄성 모델을 이용한 무베어링 로터의 자이로스코픽 세차 진동 제어

  • 임병욱;김용세;신상준
    • EDISON SW 활용 경진대회 논문집
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    • 제6회(2017년)
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    • pp.270-281
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    • 2017
  • 본 논문에서는 헬리콥터 블레이드에서 발생하는 자이로스코픽 세차 진동에 대해 연구하고, 능동 제어기 설계를 통하여 진동 저감 시뮬레이션을 수행한다. 이를 위해, 헬리콥터의 전진 비행시 동역학적 응답을 외팔보 조건을 갖는 회전익의 해석이 가능한 EDISON의 기하학적 정밀 보 구조동역학 프로그램을 이용하여 구조 해석을 진행하고 이를 단순 공기력 모델과 연성하여 공탄성 해석을 수행하였다. 실시간 구조 응답을 구하기 위해 EDISON 프로그램 해석 결과를 비선형 수식으로 모델링하는 기법과 트림해석에는 Newton-Raphson 기법 등이 사용되었다.

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TDC와 ETDO를 이용한 유도무기용 전기식 날개구동장치의 위치제어 (A Position Control of an Electrical Fin Actuator for Guided Missile using TDC and ETDO)

  • 이영철;이흥호
    • 대한전기학회논문지:시스템및제어부문D
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    • 제55권8호
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    • pp.353-362
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    • 2006
  • This paper illustrates the practical design procedure on a position control of an electrical fin actuator for the guided missile using Time Delay Control(TDC) and Enhanced Time Delay Observer(ETDO). Since TDC is robust to the model uncertainties such as the parameter variation and the external disturbance, it has been frequently used in nonlinear control systems. For a position control of an electrical fin actuator in the missile system, TDC requires the velocity sensor as well as the position sensor. To resolve the problems of the cost, the space and the malfunction due to the velocity sensor, ETDO is used as the velocity observer. ETDO is enhanced version of TDO that has the problems of the reconstruction errors and the restriction on selecting its gains. To maximize the control performance, the parameters of ETDO are optimized by using the genetic algorithm. The effectiveness of this approach is proved through a series of simulation studies and experiments, and the designed controller is compared with the typical TDC and TDC using the reduced oder observer.

Reproductive Isolation between Moroco oxycephalus and M. lagowskii (Pisces; Cyprinidae) in Korea

  • Kang, Young-Jin;Min, Mi-Sook;Yang, Suh-Yung
    • Animal cells and systems
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    • 제4권2호
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    • pp.109-115
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    • 2000
  • To clarify taxonomic status of the two sibling species, Moroco oxycephalus and M. lagowskii reproductive isolation mechanisms were investigated at sympatric area located in Kansung-up, Kosung-gun, Kangwon-do, Korea. Genetic analysis was performed to reveal mating system and intensity of Hybridization between the two species. The frequencies of hybrids were increased since 1989, and then the observed hybrid frequencies ($H_O$) did not significantly differ from the expected hybrid ($H_E$) in 1998 and 1999. However, based on histological analysis of two parents and their hybrid s gonads, the hybridizations between M. oxycephalus and M. lagowskii produced mostly fertile females but sterile males in accordance with Haldane s rule. Although it was suspected that pre- and postmating isolation mechanisms were affected between the two species, M. oxycephalus and M. lagowskii seemed to be strongly isolated with microhabitat at sympatry until 1997. Since 1998, hybrid frequencies were increased by habitat disturbance. However, their hybrid frequencies would be reduced by postmating isolation mechanisms. Therefore, the two species are considered to be distinct species recently diverged.

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동력 분산형 고속전철의 전자파 Source 및 Victim에 관한 연구 (Study on the Electromagnetic Sources and Victims of the High-Speed EMU)

  • 김윤명;주영준;구은희;구본철;유재성
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 춘계학술대회 논문집
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    • pp.1209-1212
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    • 2008
  • 동력분산형 고속전철은 분산된 EMI 발생원(source)을 가지도록 제작되기 때문에, 분산된 전자계 감수품(感受品, victim) 가까이에서 기존의 동력집중형 시스템보다 전자계 발생원을 더 많이 가지고 있다. 이 연구에서는, 전자계 발생원들과 전자계 감수품들을 확인하고, 고속전철 시스템의 안전 운행을 위하여 EMI/EMS/EMC를 취급하는 방법을 개발한다. 개발되는 내용은, 고속전철의 전자파 장해 방지 측정과 기준연구, 제어용 부품 등에 대한 EMI/EMS 기준 수립, 그리고 시제품에 대한 EMI/EMC 시험 및 평가이다. 또한 최신 무선 통신 장비에 의한 영향과 PLD(전원선 교란)에 의한 효과도 이 연구에서 조사될 것이다.

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고체 내부의 구조적 변화를 위한 Laser Pulse의 설계 (Designing Laser Pulses for Manipulating the Interior Structure of Solids)

  • 김영식
    • 대한화학회지
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    • 제39권1호
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    • pp.14-22
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    • 1995
  • 주어진 시간에 금속 고체 내부의 목표 부위에 탄성에너지를 집중시킬 수 있도록 표면에 가해주는 최적의 레이저 pulse의 형태를 디자인 하는 문제에 관하여 연구하였다. 금속고체 표면에 레이저를 쪼여주면 흡수된 광에너지가 열로 바뀌어 열팽창에 의하여 종파와 횡파가 고체 내부로 전파된다. 최소의 레이저의 세기를 사용하고 다른 부위에 영향을 최소화하면서 목표 부위에 원하는 에너지를 집중시킬 수 있는 최적의 레이저 펄스의 형태를 공액 변화 방법과 반 공간 Green 함수를 이용한 유한 요소법으로 조사하였다. 최적의 레이저 펄스로부터 원하는 시간에 목표 부위에 탄성에너지를 집중시키는 것을 보여주었고 또한 대부분의 에너지가 방향성이 큰 횡파로부터 온다는 것을 알았다.

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비축대칭 3차원 모조 소용돌이를 이용한 열대저기압의 진로 및 강도예측 (Tropical Cyclone Track and Intensity Forecast Using Asymmetric 3-Dimensional Bogus Vortex)

  • 이재덕;정형빈;강현규;권인혁
    • 대기
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    • 제24권2호
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    • pp.207-223
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    • 2014
  • The bogussing method was further developed by incorporating the asymmetric component into the symmetric bogus tropical cyclone of the Structure Adjustable Balanced Vortex (SABV). The asymmetric component is separated from the disturbance field associated with the tropical cyclone by establishing local polar coordinates whose center is the location of the tropical cyclone. The relative importance of wave components in azimuthal direction was evaluated, and only two or three wave components with large amplitude are added to the symmetric components. Using the Weather Research and Forecast model (WRF), initialized with the asymmetric bogus vortex, the track and central pressure of tropical cyclones were predicted. Nine tropical cyclones, which passed over Korean peninsula during 2010~2012 were selected to assess the effect of asymmetric components. Compared to the symmetric bogus tropical cyclone, the track forecast error was reduced by about 18.9% and 17.4% for 48 hours and 72 hours forecast, while the central pressure error was not improved significantly. The results suggest that the inclusion of asymmetric component is necessary to improve the track forecast of tropical cyclones.

The Solar-Type Contact Binary BX Pegasi Revisited

  • Lee, Jae-Woo;Kim, Seung-Lee;Lee, Chung-Uk;Youn, Jae-Hyuck
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2009년도 한국우주과학회보 제18권2호
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    • pp.24.2-24.2
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    • 2009
  • We present the results of new CCD photometry for the contact binary BX Peg, made during three successive months beginning on September 2008. As do historical light curves, our observations display an O'Connell effect and the November data by themselves indicate clear evidence for very short-time brightness disturbance. For these variations, model spots are applied separately to the two data set of Group I (Sep.--Oct.) and Group II (Nov.). The former is described by a single cool spot on the secondary photosphere and the latter by a two-spot model with a cool spot on the cool star and a hot one on either star. These are generalized manifestations of the magnetic activity of the binary system. Twenty light-curve timings calculated from Wilson-Devinney code were used for a period study, together with all other minimum epochs. The complex period changes of BX Peg can be sorted into a secular period decrease caused dominantly by angular momentum loss due to magnetic stellar wind braking, a light-travel-time (LTT) effect due to the gravitational effect of a low-mass third companion, and a previously unknown short-term oscillation. This last period modulation could be produced either by a second LTT orbit with a period of about 16 yr due to the existence of a fourth body or by the effect of magnetic activity with a cycle length of about 12 yr.

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노치 대역을 개선한 이미지 흔들림 보정 장치의 동특성 향상과 이미지 분석 (Improvement of Dynamic Characteristics of OIS System using Improved Band Notch and Analysis of Images)

  • 손동훈;박노철;박영필;박경수
    • 정보저장시스템학회논문집
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    • 제7권2호
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    • pp.70-74
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    • 2011
  • The mobile camera module is a device to be inserted in the digital device for camera feature. The mobile camera module is being shaken by vibrations such as handshake during the exposure time. The clarity is compromised by these vibrations, thus the vibration is considered as an external disturbance. Moreover the use of mobile camera module has been being expanded for automotive vibration should be considered. These external disturbances can cause image blurring, thus optical image stabilization should be applied for image compensation. The compensator is fulfilled mechanically by movable lens group or image sensor that adjusts the optical path to the camera movement. Open loop control is useful for well-defined systems like compliant mechanism. Notch filter and lead compensator are designed and applied to improve the stability and bandwidth. The final level of image compensating is confirmed by image processing with MATLAB and CODE V to verify the better performance.

교통사고후유증(交通事故後遺症)(편타성(偏墮性) 손상(損傷))에 대한 침구치료(鍼灸治療)의 접근(接近) (A Study on Acupuncture Treatment for Disorders following Whiplash Injuries)

  • 김민아;박용진
    • Journal of Acupuncture Research
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    • 제17권3호
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    • pp.75-86
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    • 2000
  • Objectives : This study is to applied effectively to the acupuncture treatment for disorders following whiplash injuries. Methods : This study suggests five various ways and principtes of treating disorders following whiplash injuries by means of acupuncture. First principle is that acupuncture treatment is carried out on acupoint far from cervical spine at acute stage, on the other hand, Extraordinary Vessel and other acupuncture treatment such as five element acupuncture treatment is applied at chronic stage in order to control balance disoders due to cervical pathology. Second is acupuncture treatment will be performed in group of three part of Meridian System-Yangmyung, Taeyang, Soyang-according to cervical kinetic, its characteristic and location of pain. Third is acupuncture treatment could be performed on basis of theory of Eohyel-disorders and disturbance of blood circulation. Fourth is to decrease tension of SCM muscle, because disorders following whiplash injuries has much association to injury of CM muscle and is simillar to tension syndroms of SCM muscle. fifth is taping therapy could control and decrease disorders following whiplash injuries based on spiral balance taping theory. Conclusions : These results suggest that acupuncture treatment for disorders following whiplash injuries will significally decrease pain and control syndrom caused by cervical disorder.

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녹용약침(鹿茸藥鍼)이 골형성(骨形成)에 미치는 영향(影響) (Healing of Bony Defects by Cervi Pantotricuhum Cornu Herbal Acupuncture)

  • 한상원;최제용;이윤호
    • Journal of Acupuncture Research
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    • 제18권5호
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    • pp.135-146
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    • 2001
  • Objective : Bone homeostasis is maintained by balance of bone formation and resorption. Therefore, bone related diseases arose by disturbance of this balance between osteoblast and osteoclast activities. To develop a successful screening system of the therapeutic components based on oriental medicine is essential to set out systematic approach for that purpose. Methods : This study was perforated Sprague-Dawley rat femur for bony defects(${\phi}5mm$) by the fissure bur. And experimetal group were treated with Cervi Pantotricuhum Cornu injection at both $Sh{\grave{e}}nsh{\tilde{u}}$(BL23) & $D{\grave{a}}zh{\grave{u}}(BL11)(0.2m{\ell})$. This was evaluated by radiography and histological analysis with in situ hybridization. Results : Cervi Pantotricuhum Cornu Herbal Acupuncture has weak effect on bony defect healing and this was evaluated by X-ray taking and histological analysis with in situ hybridization. Osteocalcin gene expression was not changed by Cervi Pantotricuhum Cornu Herbal Acupuncture in bony defects animal model. Conclusion : Taken together this study show that the Cervi Pantotricuhum Cornu herbal-acupuncture has a weak effect healing of bony defects, this type of approach might give a good chance to explore the favorable effects of Cervi Pantotricuhum Cornu herbal-acupuncture on bone tissue.

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