• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.2
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• pp.125-133
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• 2017

This paper presents the inter-rater reliability of finger spasticity assessment tested realized by using finger simulator that mimics finger spasticity of patients after a stroke. For controlling the simulator torque, finger spasticity was modeled, and the model parameters were obtained by measuring quantitative data while grading based on Modified Ashworth Scale (MAS). A robotic finger simulator was designed for mimicking finger spasticity. Evaluation of this simulator with the help of seven rehabilitation doctors showed that the simulator had a Cohen's kappa value of 0.619 for Metacarpophalangeal Joint and 0.514 for Proximal Interphalangeal Joint. Fleiss' kappa between raters is 0.513 for Metacarpophalangeal Joint and 0.486 for Proximal Interphalangeal Joint. Therefore, the spasticity assessment made by MAS grade system is not reliable owing to the subjectivity of the assessment. The proposed robotic simulator can be used as a training tool for improving the reliability of the spasticity assessment.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.814_815
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• 2009

본 논문은 로봇관절 구동 및 제어에 활용될 중공모터의 설계 및 특성해석에 대해 연구하였다. 로봇관절에 사용될 중공모터의 경우고 토크출력이 요구될 뿐만 아니라, 저속에서 제어 및 구동 신뢰성이 높은 운전특성이 요구된다. 또한 로봇 관절에 활용하기 위하여 배선처리가 간편한 중공타입의 구조가 요구된다. 따라서 우리는 로봇 구동 및 경량화가 가능하도록 유성기어와 결합이 가능한 외전형 타입의 영구자석 동기전동기의 설계 및 특성해석을 하였다. 먼저 로봇 관절에 적합하도록 FEA 기법을 이용하여 설계하였으며, 실제 시작기 모델을 제작하여 성능실험을 통해 제안된 모터의 특성을 분석하였다.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.3
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• pp.388-397
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• 2009

There are many tasks which require robotic manipulators interaction with environment. It consists of three control problems, i.e., position control, impact control and force control. The position control means the way of reaching to the environment. The moment of touching to the environment yields the impact control problem and the force control is to maintain the desired force trajectory after the impact with the environment. These three control problems occur in sequence, so each control algorithm can be developed independently. Especially for redundant manipulators, each of these three control problems has been important independent research topic. For example, joint torque minimization and impulse minimization are typical techniques for such control problems. The three control problems are considered as a single task in this paper. The position control strategy is developed to improve the performance of the task, i.e., minimization of the individual joint torques and impulse. Therefore, initial conditions of the impact control problem are optimized at the previous position control algorithm. Such a control strategy yields improved result of the impact control. Similarly, the initial conditions for the force control problem are indirectly optimized by the previous position control and impact control strategies. The force control algorithm uses the individual joint torque minimization concept. It also minimizes the force disturbances. The simulation results show the proposed control strategy works well.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.7 no.2
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• pp.91-99
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• 2013

The purpose of this study was to investigate the muscular activity and muscle strength for swing track of upper limbs during rowing exercise. Subject was all twenty healthy adults and they were divided into linear exercise group and elliptical exercise group in random. Subjects performed rowing exercise 3-times for a week and performed all 8-weeks. We measured realtime-surface EMG. Also we measured joint torque of elbow, ankle and lumbar in subjects using BIODEX. The result showed that when rowing exercise, elliptical track exercise had higher muscular activity in trapezius, deltoid, erector spinae, rectus femoris, biceps femoris, gastronemius than linear track exercise on more many muscle of upper and lower limbs. Also elbow joint torque and lumbar joint torque was more higher too. but linear exercise also had higher muscular activity in multifidus, tibilalis anterior than elliptical track exercise. According to this experiment, we found out that elliptical track was more efficient than linear track.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.196-196
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• 2004

원자로의 원자로 해체 처리나 테러리스트의 폭탄 제거와 같은 극한 환경에서 작동하는 로봇은 계단이나 구덩이 같은 평평하지 알은 지형을 극복하기 위해서 off-load 능력이 필요하다. 극한 환경에서의 작업은 전형적으로 원격으로 조정되는 로봇을 요구한다. 본 논문에서는 향상된 관절 트랙 구조의 로봇을 제안한다. 로봇이 계단에 접촉할 때론 고려해서 조이스틱으로 햅틱 동작을 위한 센싱 시스템이 제안된다. 추가적으로, 제안된 로봇이 계단을 등반하는 알고리즘을 제안한다.(중략)

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.1
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• pp.27-36
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• 2012

As the popularity of implant treatment using a variety of problems have been reported. The proper torque values recommended by the manufacturer and the actual tightening force applied to the observed differences. Period for each product used in this study using different torque controllers accuracy for each of the comparisons, were analyzed. Error rate varies by the manufacturer, but all the products used in the reference period for increasing the error rate increased. Repeat the initial tightening, but the reference, showed a value close to the reference value for the width of change was larger. However, increasing the number of repeated tightening of the reference value for the error rate increased, but has reduced the width of the observed changes.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.203-204
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• 2012

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.427-428
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• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1591-1592
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• 2011

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.10
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• pp.2317-2323
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• 2010

When the muscle is contracted by continuous and same, the force takes fatigue and stiffness. The aim of this study was to know how the fatigue and muscle stiffness change during an isometric contraction. Surface Electro myography(EMG) signal monitoring system and ultrasonic transducer set up the same muscle stem, subjects contract his right femoris muscle by submaximal isometric contraction(50% of MVC) until exhaustion. Before and after the test, muscle stiffness was measured and EMG was measured during the contraction. As time goes by, muscle fatigue was increased. and the stiffness was shown strongly after the contraction. These results show if the muscle becomes more and more fatigued, the circulation of muscle is delayed although the contraction doesn't happen. So muscle stiffness is increased.