• Journal of the Society of Naval Architects of Korea
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• v.48 no.6
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• pp.516-527
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• 2011

This paper considers a numerical analysis of ship maneuvering performance in the high amplitude incident waves by adopting linear and nonlinear ship motion analysis. A time-domain ship motion program is developed to solve the wave-body interaction problem with the ship slip speed and rotation, and it is coupled with a modular type 4-DOF maneuvering problem. Nonlinear Froude-Krylov and restoring forces are included to consider weakly nonlinear ship motion. The developed method is applied to observe the nonlinear ship motion and planar trajectories in maneuvering test in the presence of incident waves. The comparisons are made for S-175 containership with existing experimental data. The nonlinear computation results show a fair agreement of overall tendency in maneuvering performance. In addition, maneuvering performances with respect to wave slope is predicted and reasonable results are observed.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.6
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• pp.52-62
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• 1999

This paper presents a system which recognizes dynamic hand gestures on-line for controlling motion of numan avatar in virtual environment(VF). A dynamic hand gesture is a method of communication between a computer and a human being who uses gestures, especially both hands and fingers. A human avatar consists of 32 degree of freedom(DOF) for natural motion in VE and navigates by 8 pre-defined dynamic hand gestures. Inverse kinematics and dynamic kinematics are applied for real-time motion control of human avatar. In this paper, we apply a fuzzy min-max neural network and feature analysis method using fuzzy logic for on-line dynamic hand gesture recognition.

• Korean Journal of Computational Design and Engineering
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• v.9 no.3
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• pp.212-219
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• 2004

This paper presents the visualization method of the KAIST interactive bicycle simulator. The simulator consists of two bicycles of 6 DOF and 4 DOF platforms, force feedback handlebars and pedal resistance systems to generate motion feelings; a real-time visual simulator, a HMD and a beam projection system; and a 3D sound system. The system has an integrating control network with the server-client network structure for multiple simulators. The visual simulator generates dynamic images in real-time while communicating with other modules of the simulator. The operator of the simulator can have realistic visual experience of riding on a velodrome or through the KAIST campus, while being able to watch the other bicycle with an avatar.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.6
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• pp.187-192
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• 2007

In this paper we present a 3-DOF manipulator of which task is to unload the product from a micro factory. The micro factory developed by KITECH presses sheet metal to produce a micro valve that is used for micro pump. Our research is focused on the development of a small-sized unloading manipulator which works in the narrow workspace between the dies. We have implemented pick-and-place task with vacuum pressure and 3-DOF motion with stepping motors. We present the design procedures and analysis required in each module.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.11
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• pp.171-179
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• 2003

This paper presents a rehabilitation exercise system which utilizes a 6 DOF robot as a motion generator. This system was proposed for a stroke patient or a patient who has hemiplegia. A master-slave system was designed to exercise either paralysis or abnormal limb by using normal limb motion. The study on the human body was applied to calculate the motion range of elbows and shoulders. In addition, a force-torque sensor was applied to the slave robot to estimate the rehabilitation extent of the patient. Therefore, the stability of the rehabilitation robot could be improved. By using the rehabilitation robot. the patients could exercise by themselves without assistance. In conclusion, the proposed system was verified by computer simulations and system experiment.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.499-502
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• 1989

This paper is concerned with the stability analysis and the design of an auto pilot using direct model reference adaptive control for BTT missile with unknown dynamics when subjected to the longitudinal and lateral gusts. A motion of BTT missile can be separated into the longtudinal and lateral motione. The proposed algorithm is introduced different leakage terms about each motion into adaptation so as to prevent drift of the adaptive gain and alleviate gust effects and cross-coupling. The algorithm is applied to the 6DOF motion of an EMRAAT missile.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.150-153
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• 1995

In this paper the attitude control system is developed for longitudinal motion of Foil-Catamaran in regular waves with all-movable foils which attached to fore and after part of the ship and verified the system by theoretical calculation and model-tests. The linearized equations of motion of the ship is employed to apply the linear control theories, the PID control and the LQR. The strip method was used to calculate hydrodynamic coefficients and wave exciting forces of the demi hull, and unsteady hydrodynamic forces of foils are considered by using the result of Wu(1972). About 40-60% of motions is reduced in experiments. The control system described in this paper is able to extended to 6-DOF motions or control in irregular wave with trivial modification. And it is applicable to hull shape development for better seakeeping performance and to determine the size and the position of hydrofoils for the attitude control.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.11 s.176
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• pp.182-189
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• 2005

The human knee joint is the intermediate joint of the lower limb that is the largest and most complex joint in the body. Understanding of joint-articulating surface motion is essential for the joint wear, stability, mobility, degeneration, determination of proper diagnosis and so on. However, many studies analyzed the passive motion of the lower limb because of the skin marker artefact and some studies described medial and lateral condyle of a femur as a simple sphere due to the complexity of geometry. Thus, in this paper, we constructed a three-dimensional geometric model of the human knee from the geometry of its anatomical structures using non-uniform B-spline surface fitting as a study for the kinematic analysis of more realistic human knee model. In addition, we developed and verified 6-DOF contact model of the human knee joint using $C^2$ continuous surface of the inferior region of a femur, considering the relative motion of shank to thigh during locomotion.

• The Journal of Korea Robotics Society
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• v.3 no.4
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• pp.263-269
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• 2008

Visual odometry is a popular approach to estimating robot motion using a monocular or stereo camera. This paper proposes a novel visual odometry scheme using a stereo camera for robust estimation of a 6 DOF motion in the dynamic environment. The false results of feature matching and the uncertainty of depth information provided by the camera can generate the outliers which deteriorate the estimation. The outliers are removed by analyzing the magnitude histogram of the motion vector of the corresponding features and the RANSAC algorithm. The features extracted from a dynamic object such as a human also makes the motion estimation inaccurate. To eliminate the effect of a dynamic object, several candidates of dynamic objects are generated by clustering the 3D position of features and each candidate is checked based on the standard deviation of features on whether it is a real dynamic object or not. The accuracy and practicality of the proposed scheme are verified by several experiments and comparisons with both IMU and wheel-based odometry. It is shown that the proposed scheme works well when wheel slip occurs or dynamic objects exist.

• Journal of Navigation and Port Research
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• v.44 no.5
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• pp.363-374
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• 2020

In the past, various research on the effects of waves generated by ships has been investigated. The most noticeable effect of the waves generated by a passing ship is the increase of the hydrodynamic forces and the unwanted large motion of the moored ship and high mooring forces that occur. Thus, it is crucial to investigate the effect of the waves generated by the passing ship near port on the motion of the moored ship and the tension of the mooring lines. A model test was performed with virtual ship-generated waves in a square tank at CWNU (Changwon National University). The IMU (Inertial Measurement Unit) and Optical-based system were used to measure the 6DOF (Six Degrees of Freedom) motion of the moored floater. Additionally the tension of mooring lines were measured by the tension gauges. The effects of the wave direction and wave height generated by the virtual ship-generated waves on the motion of the moored floater were analyzed.