http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
조형래,홍금식 釜山大學校生産技術硏究所 1996 生産技術硏究所論文集 Vol.51 No.-
본 논문은 병렬형 매니퓰에이터의 구동부에 입력되는 힘과 상판으로 출력되는 힘과 모우멘트의 전달특성을 연구하였다. 이러한 전달특성을 연구하기 위하여 상관좌표계의 원점을 기준으로한 힘과 모우멘트 벡터로 구성되는 행렬을 힘과 모우멘트의 2부분으로 분리한 후 특이값 분해를 통하여 힘 및 모우멘트의 조종성능, 민감도, 방향성 등을 해석하였다. 이렇게 해석된 결과들은 병렬형 매니퓰레이터의 설계변수의 한 지침으로 사용되어질 수 있다. This paper presents how the input forces through the prismatic joints of the Stewart platform manipulator are transmitted to the upper plate. The matrix containing unit vectors along the legs and moment vectors about the origin of platform based on the plucker coordinate system is splitted into two parts to consider the force and moment transmissions, respectively. Manipulability and sensitivity were investigated in accordance with the changes of radius of platform and angle between legs. Acquired results could be useful in-determining design parameters like radius of platform, angle between joints in the base and platform, etc.
Hong, Keum Shik,Kim, Y. M.,Choi, J. T.,Shin, K. T.,Yeom, Y. I. 대한기계학회 1996 International Sessions in Celebration of the 50th Vol.1 No.1
An inverse kinematics problem of a reclaimer which excavates and 'transports raw materials in the raw yard is investigated. Two approaches are investigated in obtaining the inverse kinematics solution. The first method pre-assigns the 1eight of excavation point which is determined through path planning. A closed form solution is obtained for the first approach. The second method exploits the orthogonality between the normal vector at an excavation point and the rotational axis of rotating drum. The geometry near the reclaiming point has been approximated as a plane, and the plane equation has been obtained by the least square method considering 8 adjacent points near the point. A closed form solution is not found for the second approach, however a linear approximate solution is provided.
Model Reference Adaptive Control of a Time-Varying Parabolic System
Hong, Keum-Shik,Yang, Kyung-Jinn,Kang, Dong-Hunn The Korean Society of Mechanical Engineers 2000 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.14 No.2
Related to the error dynamics of an adaptive system, averaging theorems are developed for coupled differential equations which consist of ordinary differential equations and a parabolic partial differential equation. The results are then applied to the convergence analysis of the parameter estimate errors in the model reference adaptive control of a nonautonomous parabolic partial differential equation with lowly time-varying parameters.
Existence of Initial Dip for BCI: An Illusion or Reality
Hong, Keum-Shik,Zafar, Amad Frontiers Media S.A. 2018 Frontiers in neurorobotics Vol.12 No.-
<P>A tight coupling between the neuronal activity and the cerebral blood flow (CBF) is the motivation of many hemodynamic response (HR)-based neuroimaging modalities. The increase in neuronal activity causes the increase in CBF that is indirectly measured by HR modalities. Upon functional stimulation, the HR is mainly categorized in three durations: (i) initial dip, (ii) conventional HR (i.e., positive increase in HR caused by an increase in the CBF), and (iii) undershoot. The initial dip is a change in oxygenation prior to any subsequent increase in CBF and spatially more specific to the site of neuronal activity. Despite additional evidence from various HR modalities on the presence of initial dip in human and animal species (i.e., cat, rat, and monkey); the existence/occurrence of an initial dip in HR is still under debate. This article reviews the existence and elusive nature of the initial dip duration of HR in intrinsic signal optical imaging (ISOI), functional magnetic resonance imaging (fMRI), and functional near-infrared spectroscopy (fNIRS). The advent of initial dip and its elusiveness factors in ISOI and fMRI studies are briefly discussed. Furthermore, the detection of initial dip and its role in brain-computer interface using fNIRS is examined in detail. The best possible application for the initial dip utilization and its future implications using fNIRS are provided.</P>