• 제목/요약/키워드: Relative stability

검색결과 914건 처리시간 0.034초

치의학을 위한 이중노출 홀로그래피 간섭기법 연구 (A Study on the Double Exposure Holographic Interferometry for Dental Science)

  • 길상근;강흥석;최평석;박한규
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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    • pp.418-421
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    • 1988
  • Holographic interferometry is applied in dental research to study the motion of teeth and the deformation of the associated facial structure. We consider double exposure holographic interferometry which has limiting factors such as the stability of fringes, the recording time, the amount of exposure, the localization of fringes and sensitivity. These factors are taken into account to make interferogram. The resulting interferogram gives fringe pattern which is analyzed qualitatively to determine the relative rotation and the deformation of the facial structure.

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ECR CVD 방법에 의해 증착된 저유전율 SiOF 박막특성 (Propcrties of Low Delectric Constant SiOF Films Formed by ECR CVD)

  • 장원익;강승열;백종태;유형준
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1996년도 추계학술대회 논문집
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    • pp.386-388
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    • 1996
  • Low dielectric constant fluorinated oxide (SiOF) films were deposited using SiF$_4$/O$_2$/SiH$_4$mixtures by electron cyclotron resonance chemical vapor deposition (ECR CVD). Chemical composition of SiOF films was investigated by Fourier transform infrared spectroscopy (FT-lR). The fluorine content in the SiOF film observed by X-ray photoelectron spectroscopy (XPS). The dielectric constant decreased with increasing of the SiF$_4$ flow rate about 8sccm. The SiOF film, deposited with SiF$_4$=8 sccm, exhibited a F content of 5 atomic % and a relative dielectric constant 3.45. For evaluating SiOF films stability, humidity tests were performed.

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A Model Predictive Controller for The Water Level of Nuclear Steam Generators

  • Na, Man-Gyun
    • Nuclear Engineering and Technology
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    • 제33권1호
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    • pp.102-110
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    • 2001
  • In this work, the model predictive control method was applied to a linear model and a nonlinear model of steam generators. The parameters of a linear model for steam generators are very different according to the power levels. The model predictive controller was designed for the linear steam generator model at a fixed power level. The proposed controller at the fixed power level showed good performance for any other power levels by designed changing only the input-weighting factor. As the input-weighting factor usually increases, its relative stability does so. The steam generator has some nonlinear characteristics. Therefore, the proposed algorithm has been implemented for a nonlinear model of the nuclear steam generator to verify its real performance and also, showed good performance.

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Gas-liquid Chromatography에 의한 Ethambutol의 정량 (Determination of Ethambutol by Gas liquid Chromatography)

  • 이왕규;강길종;박만기
    • 약학회지
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    • 제19권4호
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    • pp.240-245
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    • 1975
  • The quantitative analysis of ethambutol.2HCl as well as commercial ehambutol preparations was undertaken by gas-liquid chromatography by finding optimum conditions, such as the use of internal standard, stability of an ethambutol-2HCl-caffeine standard solution, and the effect of column temperature, N, O-bis-(trimethylsily) acetamide [B.S.A.] concentrations and other substances present in the preparations. Under the chromatiographic conditions, an ethambutol-2HCl. caffeine standard, 9 min, 30sec. The relative molar response of ethambutol.2HCl and caffeine studied was 2.08. Ethambutol.2HCl could be quantitated up to 1$\times$10$^{-8}$ moles. the possible decomposition of B.S.A. due to the moisture when tested and the incoplete reaction for silylation could be minimized.

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고속철도교량의 온도신축길이 변화를 고려한 교량상 장대레일의 거동 해석 (Analysis of CWR track on the High-Speed Railway Bridges considering the Expansion Length of Bridge Deck)

  • 강재윤;김병석;곽종원;최은석;진원종
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2004년도 추계학술대회 논문집
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    • pp.806-811
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    • 2004
  • Currently, in the design criteria for the high speed railway bridges, the maximum distance between bridge expansion joint is limited to 80m using a continuous welded mil, in order to limit the additional stress in the rail due to the rail-bridge interaction. In the past study on the resonance effect of HSR train, it is known that the reduction of resonance and dynamic responses of bridge deck occurs at the specific expansion length of 28.05m and 46.75m. In this study, the stability of track structure on the HSR bridges with expansion length of 90m has checked by finite element method. And the track behavior including mil stresses and relative displacements are compared to the current state of track structures on the bridge system with 80m long expansion length.

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고무차륜 트램을 위한 자기장을 이용한 자율주행시스템 개발 (Autonomous driving system by electromagnetic field for rubber tired TRAM)

  • 목재균;장세기;정우성;표명덕
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2004년도 추계학술대회 논문집
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    • pp.180-185
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    • 2004
  • This paper shows how can be controlled the rubber tired TRAM by electromagnetic field with a specific pattern as autonomous driving system. The system is composed with drive elements. steering elements. navigational devices. transmitter/receivers and sensor means for sensing the position relative to the magnetic markers. There are difficulties in sensing track conditions. curvatures. slops etc. forward compared to that of the control system optically. The sensing track conditions previously is important for running stability and riding comfort. This paper shows how can achieve track condition in advance by means of electromagnetic pattern originally.

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콘크리트중 코팅철근의 부착응력에 대한 기초적 연구 (A Study on the Bond Strength of Coated Rebar in Concrete)

  • 문한영;김성수;류재석;김성섭
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1996년도 가을 학술발표회 논문집
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    • pp.127-132
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    • 1996
  • Recently in the country a corrosion of steel is accelerated due to using of sea sand including salts, and critical problem on the durability of concrete structure is occured. Thus a control of steel corrosion is very important in the stability of structure. Coated steel is in use with a method of steps of steel corrosion in U.S,A. Japan etc, and as well in domestic case the manufactured coating steel of three types is on the market. Those are Epoxy coated steel, Zinc-strength, concrete specimen size, bar diameter, which can affect bond characteristics between steel and concrete in order to know their relative bond characteristics.

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Influence of Differential Moisture Distribution on SRC Column Shortening

  • Seol Hyun-Cheol;Kim Jin-Keuna;Kim Yun-Yonga;Kwon Seung-Heea
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 봄학술 발표회 논문집(I)
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    • pp.423-426
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    • 2005
  • Steel reinforced concrete (SRC) columns, which are widely employed in high-rise buildings, exhibit particular time-dependent behavior due to creep and shrinkage of the concrete, and this behavior may cause problems related to serviceability and structural stability. SRC columns also exhibit a time-dependent, cross-sectional relative humidity distribution that differs from reinforced concrete (RC) columns, due to the presence of an inner steel plate, which interferes with the moisture diffusion of concrete. This differential moisture distribution of SRC columns may reduce the drying shrinkage and the drying creep as contrasted with RC columns. Therefore, we propose that the differential moisture distribution be taken into account to accurately predict SRC column shortening.

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수직면 직선추종유도법칙 설계 (A Vertical Line Following Guidance Law Design)

  • 황익호;조성진
    • 전기학회논문지
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    • 제59권7호
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    • pp.1309-1313
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    • 2010
  • In this paper, we propose a novel guidance law for controlling an UAV(Unmanned Air-Vehicle) to follow a reference line in vertical plane. A kinematics model representing the relative motion of the UAV to the reference line is derived. And then LQR(Linear Quadratic Regulator) theory is applied to the model to derive the VLFG(Vertical Line Following Guidance) law. The resultant guidance law forms a gain-scheduling controller scheduled by a simple parameter $\sigma$ which is a function of the UAV's velocity, axial acceleration, gravity, and the slope of the reference line. Also derived is a stability condition for the $\sigma$ variation based on Lyapunov theory. Simulation results show that the proposed guidance law can be applied effectively to UAV guidance algorithm design.

카메라를 이용한 3차원 공간상의 이동 목표물의 거리정보기반 모션추정 (Motion Estimation of a Moving Object in Three-Dimensional Space using a Camera)

  • 좌동경
    • 전기학회논문지
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    • 제65권12호
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    • pp.2057-2060
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    • 2016
  • Range-based motion estimation of a moving object by using a camera is proposed. Whereas the existing results constrain the motion of an object for the motion estimation of an object, the constraints on the motion is relieved in the proposed method in that a more generally moving object motion can be handled. To this end, a nonlinear observer is designed based on the relative dynamics between the object and camera so that the object velocity and the unknown camera velocity can be estimated. Stability analysis and simulation results for the moving object are provided to show the effectiveness of the proposed method.