• 한국CDE학회논문집
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• 제19권2호
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• pp.119-128
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• 2014

Computing the natural-looking interpolation of different shapes is a fundamental problem of computer graphics. It is proved by some researchers that such an interpolation can be achieved by pursuing the isometry. In this paper, a novel coordinate system that is invariant under isometries is defined. The coordinate system can easily be converted from the global vertex coordinates. Furthermore, the global coordinates can be efficiently recovered from the new coordinates by simply solving two sparse least-squares problems. Since the proposed coordinate system is invariant under isometries, then transformations such as global rigid trans-formations, articulated posture deformations, or any other isometric deformations, do not change the coordinate values. Therefore, shape interpolation can be done in this framework without being affected by the distortions caused by the isometry.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 A
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• pp.411-413
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• 1992

This paper proposes a simple and high performance hybrid position/force control of robots based on disturbance compensation by using the disturbance observer in task coordinate space. The disturbance observer linealizes system of robot manipulators in task coordinate space and realizes acceleration control. To realize the strict acceleration control, the disturbance observer whose input is a position signal by simple computation, works as if it were a disturbance detector. The inverse kinematics can be simplified, because the disturbance observer in task coordinate space compensates not only the disturbance but also the error due to the simplification of the inverse kinematics. The new strategy is applied to a three-degrees-of freedom direct drive robot. The robust and simple hybrid position/force control is realized experimentally.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.125-130
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• 1991

This paper presents a tracking filter using pseudomeasurements in an estimated line-of-sight Cartesian coordinate system(ELCCS) whose x-axis is on the line-of-sight to an estimated target position. A target dynamics model and a measurement equation in the ELCCS are derived first and then a tracking filter in the ELCCS named moving coordinate tracking filter(MCTF) is proposed. It is shown that this MCTF is equivalent to a Kalman filter in the inertial Cartesian coordinate system which is widely used in the target tracking system. By approximating the MCTF for a pseudomeasurement noise and an error covariance matrix in the ELCCS, decoupling of three axes can be achieved. In this case, named decoupled moving coordinate tracking filter(DMCTF), computation time can be drastically reduced by utilizing its parallel structure. Finally, the stochastic properties of the MCTF and DMCTF are presented. Especially, a sufficient condition of nondestabilizing deviation for the DMCTF is proposed. The performance of the MCTF and DMCTF are compared with a conventional Kalman tracking filter.

• 한국의류산업학회지
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• 제11권5호
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• pp.709-719
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• 2009

Since the beginning of time people had been using color to mark territory and decorate their surroundings. Color was taken for granted today as an intrinsic part of every waking moment. In modern age, color education was very important curriculum of art and design. In general, color expressed by hue, value and chroma but used the tone on the design spot, therefore the tone concept education was very important to color education. In this study I planned the usable "Systematic Color Coordinate System 180" for general color education on hue and tone color system and manufactured the color papers, color chart and color code based on the system. "Systematic Color Coordinate System 180" was attached the Munsell notation and common color names which could reappear the colors when needed.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.424-429
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• 1992

A practical adaptive tracking filter for a maneuvering target is proposed in this paper by combining a modified input estimation technique with pseudo-residuals and a decoupled tracking filter in line-of-sight Cartesian coordinate system. Since the adaptive tracking filter has decoupled structure and computes maneuver input estimates for each axis separately, it requires much less computations compared with the coventional tracking filter with MIE technique without degrading performance. Also, since pseudo-measurement noises in line-of-sight Cartesian coordinate system are much less correlated compared with those of inertial Cartesian coordinate system, the proposed tracking filter produces less false alarms or miss detections to improve the performance.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.967-972
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• 2008

This paper presents the free vibration analysis of a circular plate with a concentric square hole. The present problem deals with the numerical calculation of the natural frequencies and mode shapes of vibration of the structure by means of Independent Coordinate Coupling Method (ICCM). In this study, the boundary condition is the edge of the square hole is free and the outer circular plate is simply supported. Due to the geometric abnormality, this analysis does not permit an exact solution. Since the ICCM employs coordinate systems corresponding to each domain independently, the kinetic and potential energy expressions necessary for the Rayleigh-Ritz method can be easily obtained. Lastly, the kinematic relation is imposed. In this way, the eigenvalue problem can be easily set up. The numerical results show the efficacy of the ICCM and changes in natural frequencies and modes due to the square hole size.

• 정보처리학회논문지A
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• 제8A권2호
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• pp.167-178
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• 2001

This paper presents a new methodology for specification and control of the motion of an articulated rigid body for the purposes of animation by coordinate transformations. The approach is to formulate the problem as a coordinate transformation from the joint space of the body to a user-defined animation space which is chosen for convenience in constraining the motion. Constraints are applied to the resulting coordinate transformation equations. It is sufficiently general so that it can be applied to all common types of control problems, including closed loop as well as open loop mechanisms. We also provided a new approach to simulate a closed loop mechanism, which is using animation space transformation technique. The method is formulated in detail and is demonstrated by animating the motion of an inchworm.

• 한국정밀공학회지
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• 제20권4호
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• pp.103-111
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• 2003

The Denavit-Hartenberg symbolic notation provides the framework for the convenient and systematic method for the robot manipulator kinematics, but is limited its use to the lower pair mechanism or to the single loop mechanisms. The Sheth-Uicker notation is its revised and generalized version to be extended fur the entire domain of the link mechanism including the higher pairs. This paper proposes the method that uses the Sheth-Uicker notation fur the robot kinematics modeling. It uses the instantly coincident coordinate system and the closed loop chain fur the coordinate transformation. It enables us to model the velocity kinematics of the robot that has the complex structures such as the ternary links and the wheels in a systematic and rational way. As an implementation of the proposed method, the Jacobian matrices were obtained for not only the robot with two legs and a torso, but a manipulator on a mobile platform.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
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• pp.20-25
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• 2000

In this paper, a methodology of geometrical error identification and compensation for NC machine tool position. We have proposed a reference artifact with which, in measuring the coordinate system of NC machine, the robust coordinate systems are given. The coordinate system of the NC machine could be compensated successfully with the information obtained by measuring the reference artifact and our compensation algorithm. Monte Carlo simulation is used to evaluate coordinate referencing ability and, the uncertainties of the machine tool position is estimated and observed through the compensation process by simulation.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.999-1002
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• 2002

Cylindrical Cam Mechanism is widely used in the fields of industries, such as machine tool exchangers, textile machinery. This paper proposes a method for manufacturing of cylindrical cam in Multi CNC machining center. Multi CNC machining center has two different types depending on the tilting axis. For the manufacturing procedures. in this paper the location and the orientation of cutter path are defined from shape design data of cam. The integral NC code fur the both types of multi-axis CNC machining center can be created using the coordinates mapping between design coordinates and work coordinates. Finally, CAD/CAM program is developed on $C^{＋＋}$ language. This program can display manufacturing and kinematics simulation, which can make integral NC code for multi-axis CNC machining center of two types.