• 제목/요약/키워드: three dimensional motion

검색결과 1,015건 처리시간 0.048초

Flexure hinge mechanism having amplified rectilinear motion for confocal scanning microscopy using optical section

  • Kwon, Oh-Kyu;Park, Poo-Gyeon
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.162.6-162
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    • 2001
  • Confocal scanning microscopy (CSM) is an important instrument in a wide variety of imaging applications because of its ability to provide three-dimensional images of thick, volume specimens. The mechanism for two-dimensional beam scanning and optical sectioning has an important roe in CSM as the three-dimensional profiler. This optical sectioning property arises from the use of a point detector, which serves to attenuate the signals from out-of-focus. The intensity profile for the open loop scanning should be matched with its response for the standard. The non-linearity can be minimized with the optical sectioning or the optical probe of the closed loop control. This paper shows the mathematical expression of the light such as the extinction curve in the optical fields of system using AO deflector, the axial/lateral response experimentally when the error sources change, and the methods of optical sectioning. Thorough design of optical sectioner is crucial to the success of CSM in the field ...

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전진속도를 고려한 3차원 물체의 동유체력해석 (On the Hydrodynamic Coefficients of a 3-dimensional Body with a Forward Speed)

  • 최진근;이기표
    • 대한조선학회지
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    • 제25권3호
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    • pp.19-25
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    • 1988
  • The three-dimensional boundary value problem for the unsteady motion of a ship which is translating and oscillating on the free surface of a deep water formulated. Under the assumption that the forward speed is small and order of $\varepsilon$, all formulations are made up to the first order of $\varepsilon$. For the numerical calculation, the three-dimensional source distribution method is applied, and the triangular elements are used to represent the hull surface. The results for the added mass and the damping coefficient for Series 60, $C_B=0.7$ at Fn=0 and Fn=0.2 shows good agreements with those of Inglis, Chang, and Inglis and Price.

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Two-dimensional Surface Structures of Arenthiols Studied by STM

  • 권기영
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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    • pp.89-89
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    • 2012
  • Arrangement of individual atoms and molecules with atomic precision and understanding the resulting properties at the molecular level are ultimate goals of chemistry, biology, and materials science. For the past three decades, scanning probe microscopy has made strides towards these goals through the direct observation of individual atoms and molecules, enabling the discovery of new and unexpected phenomena. This talk will discuss the origin of forces governing motion of small organic molecules and their extended self-assembly into two-dimensional surface structures by direct observation of individual molecules using scanning tunneling microscopy (STM).

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Verification and improvement of dynamic motion model in MARS for marine reactor thermal-hydraulic analysis under ocean condition

  • Beom, Hee-Kwan;Kim, Geon-Woo;Park, Goon-Cherl;Cho, Hyoung Kyu
    • Nuclear Engineering and Technology
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    • 제51권5호
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    • pp.1231-1240
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    • 2019
  • Unlike land-based nuclear power plants, a marine or floating reactor is affected by external forces due to ocean conditions. These external forces can cause additional accelerations and affect each system and equipment of the marine reactor. Therefore, in designing a marine reactor and evaluating its performance and stability, a thermal hydraulic safety analysis code is necessary to consider the thermal hydrodynamic effects of ship motion. MARS, which is a reactor system analysis code, includes a dynamic motion model that can simulate the thermal-hydraulic phenomena under three-dimensional motion by calculating the body force term included in the momentum equation. In this study, it was verified that the dynamic motion model can simulate fluid motion with reasonable accuracy using conceptual problems. In addition, two modifications were made to the dynamic motion model; first, a user-supplied table to simulate a realistic ship motion was implemented, and second, the flow regime map determination algorithm was improved by calculating the volume inclination information at every time step if the dynamic motion model was activated. With these modifications, MARS could simulate the thermal-hydraulic phenomena under ocean motion more realistically.

동적원심모형 시험을 이용한 부지응답해석 검증시 입력 지진의 결정 (Appropriate Input Earthquake Motion for the Verification of Seismic Response Analysis by Geotechnical Dynamic Centrifuge Test)

  • 이진선
    • 한국지진공학회논문집
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    • 제17권5호
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    • pp.209-217
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    • 2013
  • In order to verify the reliability of numerical site response analysis program, both soil free-field and base rock input motions should be provided. Beside the field earthquake motion records, the most effective testing method for obtaining the above motions is the dynamic geotechnical centrifuge test. However, need is to verify if the motion recorded at the base of the soil model container in the centrifuge facility is the true base rock input motion or not. In this paper, the appropriate input motion measurement method for the verification of seismic response analysis is examined by dynamic geotechnical centrifuge test and using three-dimensional finite difference analysis results. From the results, it appears that the ESB (equivalent shear beam) model container distorts downward the propagating wave with larger magnitude of centrifugal acceleration and base rock input motion. Thus, the distortion makes the measurement of the base rock outcrop motion difficult which is essential for extracting the base rock incident motion. However, the base rock outcrop motion generated by using deconvolution method is free from the distortion effect of centrifugal acceleration.

요추 신전 자세에서 야구, 축구 선수 및 일반대학생의 커플모션 연구 (A Study of Coupled Motion of Lumbar Spine in Extended Posture in Football, Baseball Players and General Students)

  • 문옥곤;정한신
    • 대한통합의학회지
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    • 제1권3호
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    • pp.29-35
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    • 2013
  • Purpose : To offer coupled motion caused by sidebending in the extension postures in lumbar spine in the football, baseball players and general students. Method : Coupled motion were analysed by three dimensional motion analyser in the sitting position during lateral bending. Result : Regardless of the direction of sidebending at L1-L3, L5-S2 in the extension posture of the lumbar spine, the direction of coupled motion in the baseball and football players were opposite to the direction of sidebending but the direction of coupled motion was same at L3-L5. while, the direction of sidebending at L1-L3, L3-L5 in the extension posture of the lumbar spine, the direction of coupled motion in the general students were same to the direction of sidebending but, the direction of coupled motion was opposite direction at L5-S2. Conclusion : we found a difference of coupled motion between athletes and non-athletes.

로봇 머니퓰레이터의 정상상태 위치오차를 제거할 수 있는 퍼지제어 알고리듬 (Fuzzy Control Algorithm Eliminating Steady-state Position Errors of Robotic Manipulators)

  • 강철구;곽희성
    • 대한기계학회논문집A
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    • 제21권3호
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    • pp.361-368
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    • 1997
  • In order to eliminate position errors existing at the steady state in the motion control of robotic manipulators, a new fuzzy control algorithm is propeosed using three variables, position error, velocity error and integral of position errors as input variables of the fuzzy controller. Although the number of input variables of the fuzzy controller is increased from two to three, the number of fuzzy control rules is just increased by two. Three dimensional look-up table is used to reduce the computational time in real-time control, and a technique reducing the amount of necessary memory is introduced. Simulation and experimental studies show that the position errors at the steady state are decreased more than 90% compared to those of existing fuzzy controller when the proposed fuzzy controller is applied to the 2 axis direct drive SCARA robot manipulator.

유한요소-경계요소 조합에 의한 3차원 유체저장 구조물의 주파수 응답해석 (Three Dimesional Analysis of Liquid Storage Tanks Using FE-BE Coupling Method in Frequency Domin)

  • 김문겸
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 1999년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring
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    • pp.275-283
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    • 1999
  • To predict the dynamic behavior of the cylindrical liquid storage tank subjected to seismic ground motion three dimesional analysis with liquid-structure interaction must be performed, In this study a three dimensional dynamic analysis method over the frequency domain using FE-BE coupling technique which combines the efficiency of the boundary elements for liquid with the versatility of the finite shell elements for tank. The liquid region is modeled using boundary elements which can counter the sloshing effect at free surface and the structure region the tank itself is modeled using the degenerated finite shell elements. At the beginning of the procedure the equivalent mass matrix of the liquid is generated by boundary elements procedure. Then this equivalent mass matrix is combined with the mass matrix of the structure to produce the global mass matrix in the equation of the motion of fluid-structure interaction problem In order to demonstrate the accuracy and validity of the developed method the numerical results re compared with the previous studies. Finally the effects of the fluid-structure interaction on the natural frequency and dynamic response of the system are analyzed.

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