• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.62-65
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• 2006

In this paper, nonlinear nonplanar vibration of a flexible rectangular cantilever beam is analyzed when one-to-one resonance occurs to the beam. The planar and nonplanar motions of the beam are analyzed in time and frequency domains. In frequency domain, FFT analyzer is used to perform autospectrum and cepstrum analyses for nonlinear response of the beam. In time domain, an oscilloscope is used to investigate the phase difference between the planar and nonplanar motions and to perform Torus analysis in the phase space. Through those analyzing process, the main frequencies of superharmonic, subharmonic, and super-subharmonic motions are investigated in the nonplanar motion due to one-to-one resonance. Analyzing the phase difference between the planar and nonplanar motions, it is observed that the phase difference varies in time.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.819-824
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• 1997

This paper presents a cell-based motion control strategy for soccer playing mobile robots. In the central robot motion planner, the planar ground is divided into rectangular cells with variable sizes and motion indices to which direction the mobile robot should move. At every time the multiple objects-the goal gate, ball, and robots-detected, integer values of motion indices are assigned to the cells occupied by mobile robots. Once the indices being calculated, the most desirable state-action pair is chosen from the state and action sets to achieve successful soccer game strategy. The proposed strategy is computationally simple enough to be used for fast robotic soccer system.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
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• pp.1863-1866
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• 2003

In this study, respiratory motion is modeled by a 2-Dimensional linear expanding-shrinking movement. According to the introduced model, respiratory motion imposes phase error, non-uniform sampling and amplitude modulation distortions on the acquired MRI data. When the motion parameters are known or can be estimated, a reconstruction algorithm based on superposition method was used to removed the MRI artifact. For the purpose of estimating unknown motion parameters, we applied the spectrum shift method to find the respiratory fluctuation function, the x directional expansion coefficient and its center, and also we used the minimum energy method to find the y directional expansion coefficient and its center. The effectiveness of this presented method is shown by Computer simulations.

• 융합신호처리학회 학술대회논문집
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• 한국신호처리시스템학회 2003년도 하계학술대회 논문집
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• pp.58-61
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• 2003

In this study, a planar respiratory motion is modeled by a 2-D linear expanding-shrinking movement. According to the introduced model, respiratory motion imposes phase error, non-uniform sampling and amplitude modulation distortions on the acquired MRI data. When the motion parameters are known or can be estimated, a construction algorithm based on superposition method was used to remove the MRI artifact. For the purpose of estimating unknown motion parameters, we used the spectrum shift method to find the respiratory fluctuation function, the x directional expansion coefficient and its center, and we also used the minimum energy method to find the y directional expansion coefficient and its center. Finally the effectiveness of this presented method is shown by computer simulations.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1993년도 춘계학술대회 논문집
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• pp.175-180
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• 1993

The nonlinear integro-differential equations of motion of a two-link structurally flexible planar manipulator executing contact tasks are presented. The equations of motion are derived using the extended Hamilton's principle and the Galerkin criterion. Also, Models for the wrist-force sensor and impact that occurs when the manipulator's end point makes contact withthe environment are presented. The dynamic models presented can be used to studythe dynamics of the system and to design controllers.

• Journal of Advanced Marine Engineering and Technology
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• 제27권7호
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• pp.862-871
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• 2003

In this paper, we addressed a modeling for the magnetic levitation stage. This planar magnetic levitator employs four permanent magnet liner motors. Each motor generates vertical force for suspension against gravity, as well as horizontal force for propulsion. Therefore. this stage can generate six degrees of freedom motion by the combination of forces. We derived a mechanical dynamics equation using Lagrangian method and electromechanical dynamics equation by using Co-energy method. Based on the derived dynamics, we can analyze the stage motion that is subject to the input currents and forces.

• 대한인간공학회지
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• 제4권2호
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• pp.25-31
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• 1985

Mechanical energy consumption during human running was studied. The subject was modeled by an eleven segment planar open linkage system and analyzed by Newtonian equations of motion from film data with a sampling rate of 50 Hz. The motion data from films were smoothed by lower 7 harmonics before analysis. And this study was tried for a normal male subject running on a concrete floor. The mechanical energy consumption was evaluated from the five different criteria suggested by others and a joint energy consumption criterion newly devised based on the muscle contraction.

• 대한전기학회논문지
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• 제39권5호
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• pp.519-526
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• 1990

In this paper we propose the resolved motion controller using a neural network for a robot manipulator. Neural identifier designed by a neural network is trained by using a feedback force as an error signal. The identifier approximates the output of a unknown nonlinear system by monitoring both the input and the output of this system. If the neural network is sufficiently trained well, it does not require either strict modelling of the manipulator or precise parameter estimation. The effectiveness of the proposed controller is demonstrated by computer simulation using a two-link planar robot.

• Smart Structures and Systems
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• 제12권3_4호
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• pp.441-463
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• 2013

In this paper, a simplified planar model is developed for damage estimation of interlocked caisson systems. Firstly, a conceptual dynamic model of the interlocked caisson system is designed on the basis of the characteristics of existing harbor caisson structures. A mass-spring-dashpot model allowing only the sway motion is formulated. To represent the condition of interlocking mechanisms, each caisson unit is connected to adjacent ones via springs and dashpots. Secondly, the accuracy of the planar model's vibration analysis is numerically evaluated on a 3-D FE model of the interlocked caisson system. Finally, the simplified planar model is employed for damage estimation in the interlocked caisson system. For localizing damaged caissons, a damage detection method based on modal strain energy is formulated for the caisson system.

• 한국항해항만학회지
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• 제39권3호
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• pp.173-178
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• 2015

최근 국내외적으로 수중 유도무기체계 개발로 다양한 형태의 수중운동체 기술이 발전되고 있다. 특히 수중운동체 중 하나인 잠수함은 한국의 특수한 상황에서 최적의 선형설계를 위한 신뢰도 높은 조종성 평가 기술이 요구되며, 이를 위한 정확한 동유체력 계수의 추정 또한 중요한 연구 분야라 할 수 있다. 따라서 본 논문에서는 잠수함 모형을 대상으로 구속모형시험인 VPMM (Vertical Planar Motion Mechanism) 시험을 실시하여 정밀도 높은 동유체력 계수를 추정하였다. 그리고 추정된 연직면 운동에 대한 선형 (Linear) 동유체력 계수 (Hydrodynamic derivatives)들을 이용하여 동안정성 (Dynamic Stability)을 판별하였다. 그 결과, 이론추정치와의 비교를 통해 동유체력 계수의 타당성이 검증되었으며, 잠수함의 연직면 동안정성도 양호한 것으로 평가되었다. 즉, 무한수심으로 정의되는 심도 6.0의 깊은 수심으로 갈수록 주기에 따른 변화가 작아지며, 이론추정치에 근사함을 확인할 수 있었다. 한편 연직면 동안정성 판별에 있어서는, 0보다 큰 양(+)의 값을 가짐으로서 연직면 운동에 대한 동안정성을 만족하는 것으로 나타났다.