• The Journal of Korean Physical Therapy
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• v.13 no.2
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• pp.453-458
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• 2001

The aim of this study is to present the basic reference data of age and specific gait parameters for Parkinson's Disease Patients. The basic gait parameters were extracted from 5 patients, 5 men and 65 years of age using VICON 512 Motion Analyzer. The temporal gait parameters and kinematic parameters is data of Parkinson's Disease Patients. The results were as follows; 1. The cadence, velocity, stride length decreased and single limb support period, double limb support period increased than normal adult in the temporal parameters. 2. The mean angles of joint pelvic tilt and hip, knee, ankle joint decreased than normal adult at kinematic characteristics on sagittal plane. 3. The mean angles of joint pelvic tilt and hip, knee joint has no difference than normal adult at kinematic characteristics on coronal plane. 4. The mean angles of joint pelvic tilt, hip joint no difference and internal, external rotation in ankle joint significantly decreased than normal adult at kinematic characteristics on transverse plane.

• Journal of Biomedical Engineering Research
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• v.28 no.6
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• pp.744-749
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• 2007

Kinematic and kinetic analysis has been performed for Soft Golf swings utilizing realistic three dimensional computer simulations based on three dimensional motion tracking data. Soft Golf is a newly developed recreational sport in South Korea aimed to become a safe and easy-to-learn sport for all ages. The advantage of Soft Golf stems from lighter weight of the club and much larger area of the sweet spot. This paper tries to look into kinematic and kinetic aspects of soft golf swings compared to regular golf swing and find the advantages of lighter Soft Golf clubs. For this purpose, swing motions of older aged participants were captured and kinematic analysis was performed for various kinematic parameters such as club head velocity, joint angular velocity, and joint range of motions as a pilot study. Kinetic analysis was performed by applying kinematic data to computer simulation models constructed from anthropometric database and the measurements from the participants. The simulations were solved using multi-body dynamics solver. Firstly, the kinematic parameters such as joint angles were obtained by solving inverse dynamics problem based on motion tracking data. Secondly, the kinetic parameters such as joint torques were obtained by solving control dynamics problem of making joint torque to follow pre-defined joint angle data. The results showed that mechanical loadings to major joints were reduced with lighter Soft Golf club.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.9
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• pp.982-989
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• 2009

Parallel Kinematic Mechanism (PKM) is a device to perform the various motion in three-dimensional space and it calls for six degree of freedom. For example, Parallel Kinematic Mechanism is applied to machine tools, medical equipments, MEMS, virtual reality devices and flight motion simulators. Recently, many companies have tried to develop new Parallel Kinematic Mechanism in order to improve the cycle time and the precisional tolerance. Parallel Kinematic Mechanism uses general universal joint and spherical joint, but such joints have accumulated tolerance problems. Therefore, it causes position control problem and dramatically life time reduction. This paper focused on the rolling element to improve sliding precision in new sliding ball joint development. Before the final design and production, it was confirmed that new sliding ball joint held a higher load and a good geometrical structure. FEM analysis showed a favorable agreement with tensile and compressive testing results by universal testing machine. In conclusions, a new sliding ball joint has been developed to solve a problem of accumulated tolerance and verified using tensile and compressive testing as well as FEM analysis.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.4
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• pp.406-410
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• 2008

This paper presents a new robot calibration algorithm with joint stiffness parameters for the enhanced positioning accuracy of industrial robot manipulators. This work is towards on-going development of an industrial robot calibration software which is able to identify both the kinematic and non-kinematic robot parameters. In this paper, the conventional kinematic calibration and its important considerations are briefly described first. Then, a new robot calibration algorithm which simultaneously identifies both the kinematic and joint stiffness parameters is presented and explained through a computer simulation with a 2 DOF manipulator. Finally, the developed algorithm is implemented to Hyundai HX165 robot and its resulting improvement of the positioning accuracy is addressed.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.10
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• pp.2543-2554
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• 1993

In this paper, the kinematic and dynamic analyses of spatial complex kinematic chain are studied. Through the new method both using the set of identification numbers and applying the DenavitHartenberg link representation method to the spatial complex kinematic chain, the kinematic configuration of the chain is represented. Some link in the part of closed chain being fictitiously cutted, the complex kinematic chain is transformed to the branched chain. The kinematic constraint equations are derived from the constraint conditions which the cutted sections of the link have to satisfy. And the joint variables being partitioned in the independent joint variables and the dependent joint variables, the dependent variables are calculated from the independent variables by using the Newton-Raphson iterative method and the pseudoinverse matrix. The equations of motion are derived under the independent joint variables by using the principle of virtual work. Algorithms for dynamic analysis are presented and simulations are done to verify accuracy and efficiency of the algorithms.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.69-72
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• 1996

This paper considers a global resolution of kinematic redundancy under inequality constraints as a constrained optimal control. In this formulation, joint limits and obstacles are regarded as state variable inequality constraints, and joint velocity limits as control variable inequality constraints. Necessary and sufficient conditions are derived by using Pontryagin's minimum principle and penalty function method. These conditions leads to a two-point boundary-value problem (TPBVP) with natural, periodic and inequality boundary conditions. In order to solve the TPBVP and to find a global minimum, a numerical algorithm, named two-stage algorithm, is presented. Given initial joint pose, the first stage finds the optimal joint trajectory and its corresponding minimum performance cost. The second stage searches for the optimal initial joint pose with globally minimum cost in the self-motion manifold. The effectiveness of the proposed algorithm is demonstrated through a simulation with a 3-dof planar redundant manipulator.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.04b
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• pp.363-368
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• 1995

A general method of solving inverse kinematics of three-joint manipulator composed of revolute joints or prismatic joints or combinations of those joints is presented in this study. In completing real-time control, it is very important to obtain the closed form solutions of inverse kinematics rather than iterative numerical solutions, because iterative numerical solutions are generally much slower than the corresponding closed form solutions. If it is possible to obtain the inverse kinematic solutions for general cases of considering twist anlges and offsets, the manipulator work space can be designed and enlarged more effciently for specific task. Moreover, in idustrial manipulators, the effect of main three joints is larger than that of the other three joints related to orientation in the view of work space. Therfore the solutions of manin three-joint are considered. Even The inverse kinematic equations are complicatedly coupled, the systematical solving process by using symbolic calculation is presented.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.1
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• pp.197-204
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• 2004

In this study we presented kinematic and kinetic data of foot joints using approximated equations and partial plantar pressure during gait. The maximum angular displacements of each tarsometatarsal joint were found to range from 4$^{\circ}$to 7$^{\circ}$ and the maximum moments were from 200Nㆍcm to 1500Nㆍcm. It was relatively wide distribution. Foot kinematic data calculated from the approximated equations, which were represented by the correlation between moment and angular displacement, and the data from motion analysis were similar. We found that the movements of foot joint were mainly decided by the passive characteristics of the joint when ground reaction force acts. The method of kinematic and kinetic analysis using approximated equations which is presented in this study is considered useful to describe the movements of foot joints in gait simulations.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.5
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• pp.482-489
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• 1997

This paper presents the analysis of the kinematics and dynamics of redundant parallel manipulators, and provides design guides for advanced parallel mainpulators with high performance. Three types of redundancies are considered which include the redundancies in serial chain, joint actuation, and parallelism. First, the kinematic and dynamic models of a redundant parallel manipulator are obtained in both joint and Cartesian spaces, and the kinematic and dynamic manipulabilities are defined for the performance evaluation. The effects of the three types of redundancies on the kinematic and dynamic performance of a parallel manipulator are then analyzed and compared, providing a set of guides for the design of advanced parallel manipulators. Finally, the simulation results using planer parallel manipulators are given.

• The Journal of Korean Physical Therapy
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• v.25 no.5
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• pp.297-302
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• 2013

Purpose: This study was conducted in order to investigate the kinematic gait parameter of lower extremities with different gait conditions (level walking, stair, ramp) in hemiplegic patients. Methods: Ten hemiplegic patients participated in this study and kinematic data were measured using a 3D motion analysis system (LUKOtronic AS202, Lutz-kovacs-Electronics, Innsbruk, Austria). Statistical analysis was performed using one-way repeated measure of ANOVA in order to determine the difference of lower extremity angle at each gait phase with different gait conditions. Results: Affected degree of ankle joint in the heel strike phase showed significant difference between level walking and climbing stairs, and toe off phase showed significant difference between level walking and climbing stairs, ramps, and climbing stairs. Affected degree of knee joint showed no significant difference in all attempts. Affected degree of hip joint in the toe off phase showed significant difference between level walking, ramps and stairs, and climbing ramps. Swing phase showed significant difference between sides for level walking and stairs, climbing ramps. Affected ankle joint of heel strike and toe off, and affected hip joint of toe off and the maximum angle of swing phase in the angle was increased. Unaffected side of the ankle joint, knee joint, and hip joint showed a significant increase in walking phase. Conclusion: These findings indicate that compared with level walking, different results were obtained for joint angle of lower extremity when climbing stairs and ramps. In hemiplegia patient's climbing ramps, stairs, more movement was observed not only for the non-affected side but also the ankle joint of the affected side and hip joint. According to these findings of hemiplegic patients when climbing stairs or ramps, more joint motion was observed not only on the unaffected side but also on the affected side compared with flat walking.