• 제어로봇시스템학회논문지
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• 제7권6호
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• pp.518-522
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• 2001

The main problem of the calibration of robots is to measure the position and orientation of a robot end effector. The calibration methods can be used as tool to improve the accuracy of robots without change of the arm or control architecture or robots. But such calibration methods require accurate measurements. Dynamic measurement of position and orientation provides a solution for this problem and improves dynamic accuracy by dynamic calibration of robots. This paper describes the development of the laser tracking system capable of determining the static and dynamic performance of industrial robots. The structure and systems components are presented and basic experimental results are included to demonstrated the instrument performance. The system can be applied to the remote controlled mobile robots as well s the calibration of robots.

• 한국공작기계학회논문집
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• 제13권2호
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• pp.120-126
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• 2004

This study proposed the analysis of mass position detection due to the change of the mass and strifeless of structure by using the original and modified dynamic characteristics. The method is applied to examples of the cantilevers beam and the 3 degrees of freedom system by modifying the mass. The predicted detection of the mass positions and magnitudes are in good agrement with the present study from the structural reanalysis using the modified mass.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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• pp.383-385
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• 1996

In this paper, the dynamic path-following using the path-observer is proposed to improve the stability when initial position errors are considered. The dynamic path-following without the path-observer cannot follow reference path when initial position errors are large, so we propose the path-observer method. Finally, the results of simulation will be described.

• 한국컴퓨터정보학회논문지
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• 제28권7호
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• pp.95-102
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• 2023

이 연구의 목적은 8주간의 코어 훈련이 스키선수의 동적자세조절, 하체 손상 및 고유수용성 관절위치감각에 미치는 영향을 보고자 하였다. 이 연구에 참여한 대상자는 스키선수 20명으로 무작위로 코어 운동군 10명과 통제군 10명으로 분류하였다. 코어 훈련프로그램은 벤치, 사이드웨이 벤치, 프랜크, 사이드 브리지 및 서파인 브리지로 구성하였고, 8주간 주 3회 실시하였다. 연구 결과 동적자세조절 검사는 좌·우측 후방안쪽 뻗기에서 유의한 효과가 있었고, 하체 손상 준거 검사는 좌·우측 종합점수에서 통계적으로 유의한 효과가 있었다. 또한 고유수용성 관절위치감각은 왼발 15°과 왼발 45°에서 유의한 감소가 있었다. 결론적으로 8주간의 코어 훈련은 스키선수의 동적자세조절 능력, 하체 손상 감소 및 관절위치감각을 향상시키는 것으로 나타났다.

• 한국해양공학회지
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• 제28권4호
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• pp.274-279
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• 2014

This paper investigates the line dynamic forces connecting tugs and a floater, where the planar motion of the floater is due to the weather criteria during the position keeping of the offshore structure by tugs. The analysis situation consists of the position keeping states for the seabed mooring line connection work of the offshore structure at the offshore site. Specifically, the decision about the tug power capacity for the position keeping is essential and depends on the weather criteria, line characteristics, length of line, etc. The planar motion of the structure is constrained by the interference of the installation vessel's operational range, behavior of the underwater fairlead, and other surrounding structures. In this paper, the tug line forces and planar motion of an offshore structure are summarized dependent on the tug line length and line material characteristics in the states fora given floater draft and weather criteria. The tug line dynamic forces and planar motion evaluated here will be used to determine the proper tug power and clearance of an offshore structure.

• 대한정형외과학회지
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• 제55권5호
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• pp.426-430
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• 2020

극상건의 부분 파열(partial thickness tear)이 자기공명영상이나 Middleton, Crass position하의 정적초음파영상에서는 관찰되지 않는 경우가 있다. 저자들은 견관절의 extension position에서 저항 scaption (resisted scaption 또는 scapular plane abduction)을 이용한 동적초음파 검사를 이용하면 다른 영상의학적 도구나 자세에서 진단을 놓칠 수 있는 극상건의 부분 파열도 효과적으로 관찰할 수 있음을 여러 증례를 통하여 경험하였다. 현재까지 극상건 부분 파열을 진단하기 위한 동적 검사 방법은 문헌으로 보고된 적이 없었던 바, 이에 두 증례를 통하여 저항 scaption을 이용한 동적 초음파에 대한 저자들의 술기를 보고하고자 한다.

• 한국정밀공학회지
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• 제19권6호
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• pp.51-61
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• 2002

A tracking control scheme on the XY ball-screw drive system in the presence of nonlinear dynamic friction is proposed. A nonlinear dynamic friction is regarded as the Lund-Grenoble friction model to compensate effects of friction. The conventional VSC method that often has been used as a non-model-based friction controller has poor tracking performance in high-precision position tracking application since it cannot compensate the friction effect below a certain precision level completely. Thus to improve the precise position tracking performance, we propose the integral type VSC method combined with the friction-model-based observer. Then this control scheme has the high precise tracking performance compared with the non-model-baked VSC method and the PID control method with a similar observer. This fact is shown through the experiment on the XY ball-screw drive system with the nonlinear dynamic friction.

• PNF and Movement
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• 제14권2호
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• pp.149-155
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• 2016

Purpose: The purpose of this study was to investigate the effects of using proprioceptive neuromuscular facilitation (PNF) exercise in the progressive sitting position on the dynamic balance ability of a patient with a cerebellar injury. Methods: The subject had ataxia due to cerebellar injury. The subject participated in a PNF bilateral scapular pattern exercise with stabilizing reversal technique during a progressive sitting position session as well as baseline for 20 minutes a day for 4 weeks. In the first session, PNF exercises were performed at a height of 40 cm for 10 minutes, and in the second session they were performed at 50 cm for 10 minutes from a lower center of gravity (COG) to a higher COG sitting position. We used the Berg Balance Scale (BBS), Five-Times-Sit-to-Stand Test (FTSST), and the Timed Up and Go Test (TUGT) to measure the subject's dynamic balance ability every two days through the entire session. Results: After participating in the program, the subject's dynamic balance ability improved compared to the first baseline, as measured by BBS (2 points increased), FTSST (5.3 sec decreased), and TUGT (2 sec decreased). The increase was also maintained in the second baseline session. Conclusion: PNF exercise using bilateral scapula patterns with a stabilizing reversal technique helps to enhance the dynamic balance ability of a cerebellar injury patient.

• 대한조선학회논문집
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• 제40권1호
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• pp.8-19
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• 2003

Special purpose vessels such as drillship and ocean research vessels install the DPS(Dynamic Positioning System) to maintain the position and heading for long-time operation. This paper deals with the design parameters for the control theory and filter algorithms of DP system. for the environmental loadings wind forces, current forces and wave forces were considered. In order to estimate the low frequency motions without first-order wave motion, the Kalman filter was used and it was assumed that the first-order wave forces correspond to system noises and first-order wave motions are measurement noises. In this simulation, the length of research vessel is 65 meters and it has four thrusters to maintain the position. The ability of keeping position and heading was confirmed. For the calculation of thruster input the LQR and LOI control theory were adopted and the effects of gain were investigated.

• Journal of Power Electronics
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• 제10권1호
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• pp.58-64
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• 2010

In this paper, the dynamic performance of oscillating linear motors, which are used in household refrigerators, is improved by means of efficient parameter identification. Oscillating linear motor parameters are identified as a function of the piston position and the motor current. They are stored in a ROM table and used later for an accurate estimation of piston position. The identified motor parameters are also approximated to the $2^{nd}$-order surface functions, which are divided into 2 or 4 subsections in order to decrease identification errors. Experimental results are given to show that the proposed control scheme can provide oscillating linear motors with high dynamic performance.