• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1998년도 학술대회
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• pp.3-8
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• 1998

The conversion of monoscopic video to 3D stereoscopic video has been studied by some pioneering researchers. In spite of the commercial of potential of the technology, two problems have bothered the progress of this research area: vertical motion parallax and high computational complexity. The former causes the low 3D perception, while the hardware complexity is required by the latter. The previous research has dealt with NTSC video, thur requiring complex processing steps, one of which is motion estimation. This paper proposes 3D stereoscopic conversion method of MPGE encoded data. Our proposed method has the advantage that motion estimation can be avoided by processing MPEG compressed data for the extraction of motion data as well as that camera and object motion in random in random directions can be handled.

• 한국자동차공학회논문집
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• 제13권1호
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• pp.99-108
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• 2005

This paper represents an efficient modeling method of a suspension system for the vehicle dynamic simulation. The suspension links are modeled as composite joints. The motion of wheel is defined as relative one degree of freedom motion with respect to car body. The unique relative kinematic constraint formulation between the car body and wheel enables to derive equations of motion in terms of wheel vertical motion. Thus, vehicle model has ten degrees of freedom. By using velocity transformation method, the equations of motion of the vehicle is systematically derived without kinematic constraints. Various vehicle simulation such as J-turn, slowly increasing steer, sinusoidal sweep steer and bump run has been performed to verify the validity of the suggested vehicle model.

• 대한기계학회논문집A
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• 제35권7호
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• pp.767-772
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• 2011

궤적생성은 로봇보행의 안정성, 연속성 그리고 보행특성을 결정하는 가장 중요한 일이다. 보통 궤적생성법으로 LIPM을 많이 쓰지만 그것은 그것의 선형화 기법 때문에 수직방향으로의 동작생성을 할 수 없다는 단점이 있다. 이 논문에서는 ELIPM이라는 새로운 궤적생성법을 제안한다. 이 궤적생성법은 전진방향의 동작은 물론이고 수직방향의 동작을 간단하게 생성할 수 있다.

• 조명전기설비학회논문지
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• 제25권8호
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• pp.39-47
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• 2011

The motion of a conductive spherical particle under uniform electric field is investigated in order to find a suitable method for removing the conducting solid impurities contained in liquid plastic. When the positive dc voltage applied to the upper electrode, the vertical up-and-down motion of a charged particle by electrostatic force is observed by a charge-coupled device (CCD) camera or a high-speed video camera. The experimental data of the static threshold voltage by which the particle starts to move toward the counter electrode in air or silicone oil are in good agreement with theoretical value. When the applied voltage is larger than the static threshold voltage, the particle motion pattern in silicone oil consists of four stages: upward motion, stopping at the upper electrode, downward motion and stopping at the lower electrode. The stopping motion on the electrode is thought to be caused by the liquid flow accompanied by the particle motion. The particle charge calculated by integrating the pulse current, which is generated by the charge exchange between the electrode and the particle, is approximately 0.1~0.25 times of the theoretical value. This study is expected to help understand the electric properties of microparticles in oil circuit breaker (OCB) and oil transformer and improve their performance and longevity.

• 한국정밀공학회지
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• 제32권3호
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• pp.263-268
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• 2015

This paper describes lost motion analysis for a novel 6-DOF ultra-precision positioning stage. In the case of flexure hinge based precision positioning stage, lost motion is generated when the displacement of actuator is not delivered completely to the end-effector because of the elasticity of flexure hinge. Consequently, it is need to compute amount of lost motion to compensate the motion or to decide appropriate control method for precision positioning. Lost motion analysis for the vertical actuation unit is presented. The analysis results are presented in two ways: analytic and numerical analyses. It is found that they closely coincide with each other by 1% error. In finite element analysis result, the amount of lost motion is turned out to be about 3%. Although, the amount is not so large, it is necessary procedure to check the lost motion to establish the control method.

• 한국수산과학회지
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• 제38권5호
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• pp.316-322
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• 2005

In order to develop a floating breakwater, which can efficiently control long period waves, vertical plates are attached in pontoon. Wave control and dynamic behaviors of the newly developed vertical plates type are verified from numerical analysis and hydraulic experiment. As a result, for the wave control and energy dissipation, the newly developed vertical plates type is more efficient than the conventional pontoon type. For the floating body motion, the wave transmission, depending on incident wave period, is decreased at the natural frequency. Dimensionless drift distance has similar trend of the reflection rate of wave transformation near natural frequency except maximum and minimum values. Dimensionless maximum tension is 17 percent of the weight of floating breakwater in case of the conventional pontoon type and 18 percent or 14 percent in case of the newly developed vertical plates type. Thus, it is shown that the wave control is improved by the vertical plates type. In addition, by adjusting the interval of the front and back vertical plate, we would control proper wave control.

• 대한조선학회논문집
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• 제51권6호
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• pp.503-509
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• 2014

This paper describes the time-domain numerical method for prediction of slamming loads on a ship in waves using the strip theory. The slamming loads was calculated considering the relative vertical velocity between the instantaneous ship motion and wave elevation. For applying the slamming force on a ship section, the momentum slamming theory and the empirical formula-based bottom slamming force were used corresponding to the vertical location of wetted body surface. Using the developed method, the vertical bending moments, relative vertical velocities, and impact forces of S175 containership were compared in the time series for various section locations and wave conditions.

• 로봇학회논문지
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• 제2권3호
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• pp.249-254
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• 2007

본 논문에서는 웨이퍼 레벨 밀봉 실장된 수직 운동 가속도 신호를 감지할 수 있는 초소형 Z축 가속도 센싱 엘리먼트를 제작하였다. 초소형 Z축 가속도 센싱 엘리먼트는 수직 방향의 정전용량 변화를 필요로 하기 때문에 단일 기판상에 수직 단차의 형성을 가능케 하는 확장된 희생 몸체 미세 가공 기술 (Extended Sacrificial Bulk Micromachining, ESBM) 을 이용하여 제작되었다. 확장된 희생 몸체 미세 가공 기술을 이용하면 정렬오차가 없이 상하부 양쪽에 수직 단차를 갖는 실리콘 구조물의 제작이 가능하다. 또한, MEMS 센싱 엘리먼트의 부유된 실리콘 구조물을 보호하기 위하여 웨이퍼 레벨 밀봉 실장 기술이 적용하여 고신뢰성, 고수율, 고성능의 Z축 가속도 센서를 제작하였다. 신호 처리 회로와 가속도 센서를 결합하여 Z축 가속도 센싱 시스템을 제작하였고 운동가속도 범위 10 g 이상, 정지 드리프트 17.3 mg 그리고 대역폭 60 Hz 이상의 성능을 나타내었다.

• 대한기계학회논문집
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• 제16권10호
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• pp.1963-1970
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• 1992

본 연구에서는 Fig.1에 나타낸 정 등의 모델을 사용하여 공간내의 자연대류 유동을 수치적으로 해석하고 실험결과와 비교하여 수평격판에 의해서 발생하는 진동유 동의 특성을 규명하고자 한다. 본 수치해석에서는 물(Pr=4.95)을 내부유체로 하여 Rayleigh수, 공간의 폭에 대한 격판길이(L/W)및 격판의 열전도율의 변화가 자연대류 진동유동에 미치는 영향을 밝히고, 밀폐공간의 경사에 의해 진동유동이 사라지는 각 도, 즉 천이 경사각도를 찾아 내고자 한다. 이러한 유동특성을 파악하기 위하여 본 연구에서는 지배방정식을 Galerkin method를 사용한 2차원 유한요소법(FEM)으로 수치 해석하였다.

• 수산해양기술연구
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• 제51권1호
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• pp.71-78
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• 2015

In order to deduce an objective evaluation method of motion seasickness incidence (MSI) by ship motions during underway in irregular waves and to present the fundamental data of passenger comfort on the yacht and the passenger ship according to the result, the MSI of the trainees by the questionnaires was analysed and compared with the rate of variation of salivary ${\alpha}$-amylase activity (VSAA) on the training ship "A-ra ho" of Jeju national university. Relationship between rate of variation (x) by salivary ${\alpha}$-amylase activity and motion seasickness incidence (y) was described by the equation, MSI(%) = 0.6073 x + 12.189 including the correlation coefficient ($R^2=0.9853$). The result obtained through the rate of variation of salivary ${\alpha}$-amylase activity which was the quantitative evaluation method for ship motions causing seasickness was most affected by z-vertical acceleration and occurred within the frequency range 0.1 to 0.3Hz centered on 0.2Hz, and the simulation result based on this finding showed the motion seasickness rate at approximately 4% lower than the rate obtained through the survey.