• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.173-179
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• 2002

This paper presents a new approach to the design of adaptive control system using DSPs(TMS320C50) fur robotic manipulators to achieve trajectory tracking angles. Digital signal processors are used in implementing real time adaptive control algorithms to provide motion for robotic manipulators. In the proposed scheme, adaptation laws are derived from the improved second stability analysis based on the indirect adaptive control theory. The proposed control scheme is simple in structure, fast in computation, an suitable fur implementation of real-time control. Moreover, this scheme does not require an accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the adaptive controller is illustrated by experimental results for a SCARA robot.

• The Journal of Korean Physical Therapy
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• v.27 no.6
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• pp.430-433
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• 2015

Purpose: The purpose of this study was to investigate the effects of a four week unilateral isokinetic exercise program applied to ankle on the one-leg stance balance performance of ipsilateral and contralateral lower-limbs. Methods: Subjects were randomly assigned to either a right ankle training program (n=12) or a control group (n=12). The training group received unilateral ankle isokinetic exercise of the dominant side for 4 weeks, whereas control group did not. Ipsilateral and contralateral one-leg balance were measured before and after intervention using the Biodex Balance System. Results: Improvements of stability scores, such as APSI, MLSI, and OSI, from pre-test to post-test were significantly different greater for the training group when the control. Conclusion: The results of this study suggest unilateral ankle strengthening exercise transfers benefit to the untrained limb by a cross-education effect, and that this type of exercise should be considered to improve one-leg standing balance of trained and untrained lower-limbs.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.767-770
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• 1991

For the control of redundant manipulators, conventional dynamic control methods of local torque optimization showed the instability which resulted in physically unrealizable torque requirements. In this paper, a new dynamic control method which is based on the concept of aspects is proposed. The proposed method starts with the basic understanding of the minors in the Jacobian matrix. It was shown by computer simulations that the proposed method demonstrates a drastic reduction of torque loadings at the joints in the tracking motion of a long trajectory, and thus guarantees the stability of joint torque.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.5
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• pp.663-668
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• 2018

A combined CPG (Central Pattern Generator) based foot trajectory and GA (Genetic Algorithm) based joint compensation method is presented for adaptive humanoid walking. In order to increase an adaptability of humanoid walking for rough terrains, the experiment for rolling terrains are introduced. The CPG based foot trajectory method has been successfully applied to basic slops and variable slops, but has a limitation for the rolling terrains. The experiments are conducted in an ODE based Webots simulation environment using humanoid robot Nao to verify a stability of walking for various rolling terrains. The proposed method is compared to the previous CPG foot trajectory technique and shows better performance especially for the cascade rolling terrains.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.128-133
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• 2001

This paper presents a new approach to the design of adaptive control system using DSPs(TMS320C50) for robotic manipulators to achieve trajectory tracking angles. Digital signal processors are used in implementing real time adaptive control algorithms to provide motion for robotic manipulators. In the proposed scheme, adaptation laws are derived from the improved second stability analysis based on the indirect adaptive control theory. The proposed control scheme is simple in structure, fast in computation, an suitable for implementation of real-time control. Moreover, this scheme does not require an accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the adaptive controller is illustrated by experimental results for a SCARA robot.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2001.10a
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• pp.69-82
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• 2001

본 연구는 절리가 발달한 고속도로 절취 사면들의 안정성을 검토하기 위하여 수행되었다. 물성시험을 바탕으로 한 지질 강도지수(GSI)를 이용하여 절리가 발달한 암반에 대한 최적의 물성을 구하는 과정을 제시하였다. 안정성 검토를 위해 FLAC에 의한 수치해석을 실시하였으며 이 때 사용한 모델은 절리 발달 상태가 균일하게 분포하였으므로 Ubiquitous Joint Model을 선정하였다. 해석은 건기와 우기의 경우로 나누어 실시하였는데 조건에 따라 절리면의 강도를 달리 적용하였다. 본 논문은 굴착 사면에서 쉽게 접할 수 있는 절리암반 환경에서 최적의 물성을 결정하고 이를 이용하여 안정성을 분석할 패 하나의 참고자료로 활용할 수 있을 것이다.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.1052-1057
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• 1993

A scara type Direct Drive Arm(DDA) with two degrees-of-freedom is designed and implemented. The direct drive motor is used to furnish large torque to reduce the modeling error by the gear and chains. To control the DDA, a multiprocessor control structure with multirate dynamic control algorithm is designed. In the control algorithm, the dynamics of system is used to calculate the nominal control torque and the feedback controls are calculated with a parallel processing algorithm for each joint. The laboratory experiments on Hong-Ik DDA by dynamic control algorithm are presented and compared to that of PID control algorithm. This result shows that the proposed controller guarantees small trajectory error and stability. With this research, Hong-Ik DDA is expected to be utilized as A basic tool for robotics and control engineering.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.472-477
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• 1996

This paper presents a new approachtothe design of adaptive control system using DSPs(TMS320C30) for robotic manipulators to achieve trajectory tracking by the joint angles. Digital signal processors are used in implementing real time adaptive control algorithms to provide an enhanced motion control for robotic manipulators. In the proposed control scheme, adaptation laws are derived from the improved Lyapunov second stability analysis method based on the adaptive model reference control theory. The adaptive controller consists of an adaaptive feedforward controller, feedback controller, and PID type time-varying auxillary control elements. The prpposed adaptive control scheme is simple in structure, fast in computation, and suitable for implementation of real-time control. Moreover, this scheme does not require an accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the adaptive controller is illustrated by simulation and experimental results for a SCARA robot.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.41-44
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• 2005

Three precast concrete beam-column connectors for the high-rise office buildings were considered to investigate the prestressing effects of the DDC(Dywidag Ductile Connectors) of Germany and of the modified DDC. The specimens of DDC, DDC with post-tensioning and modified DDC with post-tensioning were constructed and tested to verify the safety. The DDC with and without post-tensioning showed reliable joint strength and ductility but failed in critical x-shape crackings at the column. The modified one showed better behaviors in tests because they did not show critical column crackings at failure. The use of prestressing did not helpful significantly to increase the strength and ductility of connectors but helpful only to develop self-centering behavior for stability.

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.301-303
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• 2001

This paper deals with the biped robot gait on changing the initial postures. Gait of a biped robot depends on the constraints of mechanical kinematics and initial posture. Also biped robot's dynamic walking stability is investigated by ZMP(Zero Moment Point). The path trajectory. with the knee joint bent like a human, is generated and applied with the above considerations. To decrease trajectory tracking error, in this paper, a new initial posture similar to bird's case is proposed and realized with the real robot.