• The Journal of Korean Physical Therapy
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• 제31권1호
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• pp.56-61
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• 2019

Purpose: The spasticity of stroke patients decreases the ankle range of motion and increases the gastrocnemius muscle tone. This study examined the effects of stretching exercise and far infrared irradiation on the ankle function in stroke patients with spasticity. Methods: This study was conducted on 20 stroke patients admitted to Jesaeng General Hospital, who were divided into a study group (stretching exercise with far infrared) and control group (stretching exercise only). The dorsiflexion range of motion was measured using a smartphone and the medial gastrocnemius muscle tone and stiffness were measured using a Myoton pro. Results: With the exception of the non-paretic gastrocnemius muscle tone in the control group, the medial gastrocnemius muscle tone and stiffness decreased significantly in both groups. In both groups, the dorsiflexion range of motion increased significantly. In addition, the experimental group had a significantly higher dorsiflexion range of motion than the control group. On the other hand, there was no significant difference between the two groups in terms of the medial gastrocnemius muscle tone and stiffness. Conclusion: For stroke patients with spasticity, stretching exercises increased the ankle's range of motion and decreased the gastrocnemius muscle tone. The addition of heat therapy further increased the ankle's range of motion. On the other hand, as the sample size was small, future studies should include more subjects.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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• pp.397-400
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• 1996

In this paper, robust motion control of a flexible micro-actuator is presented. The actuator is made of a bimorph piezoelectric high-polymer material (PVDF). No mathematical model system can exactly model a physical system such a flexible micro-actuator. For this reason we must be aware of how modeling errors might adversely affect the performance of a control system for such a model. The H method addresses a wide range of the control problems, combining the frequency and time domain approaches. The design is an optimal one in the sense of minimization of the maximum of the closed-loop transfer function. It includes colored measurement and process noise. It also addresses the issues of robustness due to model uncertainties, and is applicable to the, flexible micro-actuator control problem. Therefore, we adopt the H control problem to the robust motion control of the flexible micro-actuator. Theoretical and experimental results demonstrate the satisfactory performance and the effectiveness of the designed controller. the effectiveness of the designed controller.

• 제어로봇시스템학회논문지
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• 제7권8호
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• pp.697-702
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• 2001

The ring laser gyro(RLG) has been used extensively in strapdown inertial navigation system(SDINS) because of the apparent of having wide dynamic range, digital output and high accuracy. The dithered RLG system has dynamic motion at sensor level, caused by the dithering motion to overcome the lock-in threshold. In this case, an attitude error is produced by not only the true coning of the vehicle motion but also the pseudo coning of the sensor motion. This paper describes the definition of the multi-frequency coning motion and its noncommutativity error to reject the pseudo coning error produced by the sensor motion such as the dithered RLG. The simulation results are presented to minimize the multi-frequency coning error.

• 제어로봇시스템학회논문지
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• 제19권12호
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• pp.1111-1118
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• 2013

In this paper, the disturbance applied to launcher hatch by ship motions is introduced to identify the vertical ship motion disturbance. Basically, ship motions are comprised of 6 degrees of freedom: roll, pitch, yaw, heave, surge and sway. In the case of the shipboard launcher hatch the coupled pitch, heave and roll are significant motions to be transformed to a vertical direction motion. The maximum acceleration values are obtained from the vertical motion model and the ship motion data in accordance with ship type and hatch location on the ship. We verify that the maximum pitch motion mainly influences the launcher hatch and also present the quantity of the maximum load disturbance by the ship's motion acceleration.

• 대한인간공학회지
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• 제9권1호
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• pp.21-27
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• 1990

Teaching Expert System/World Coordinate System(TES/WDS) was proposed to improve robot motion control. First, precise coordinate reading for getting the inherent data about position and posture of task objects was performed throgh the integrated image and fuzzy processing. Second, singularity and parameter limitation problems in getting the motion data about position and posture of robot in macro motion were solved by proposed geometric algorithm. Third, the unnecessary robot motion was also removed by the Robot Time and Motion (RTM) method and the Multi-Geometric Straight-Line Motion (MGSLM) method in micro motion. This results demonstrated reduction of the average teaching task time according to task order.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 추계학술대회
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• pp.231-232
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• 2014

립모션 (Leap motion)센서를 사용하여 손동작을 인식하고 손가락의 위치에 따라 미리 지정된 명령어를 보행 로봇에게 전송하여 보행 로봇이 그 명령어를 수행하는 시스템을 개발하였다. 개발언어는 Processing을 사용하고 립모션 센서 라이브러리는 LeapMotionP5를 사용하였다.

• 제어로봇시스템학회논문지
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• 제22권3호
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• pp.192-198
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• 2016

Motion planning problem is still one of the important issues in robotic applications. In many real-time motion planning problems, it is advisable to find a feasible solution quickly and improve the found solution toward the optimal one before the previously-arranged motion plan ends. For such reasons, sampling-based approaches are becoming popular for real-time application. Especially the use of a rapidly exploring random $tree^*$ ($RRT^*$) algorithm is attractive in real-time application, because it is possible to approach an optimal solution by iterating itself. This paper presents a modified version of informed $RRT^*$ which is an extended version of $RRT^*$ to increase the rate of convergence to optimal solution by improving the sampling method of $RRT^*$. In online motion planning, the robot plans a path while simultaneously moving along the planned path. Therefore, the part of the path near the robot is less likely to be sampled extensively. For a better solution in online motion planning, we modified the sampling method of informed $RRT^*$ by combining with the sampling method to improve the path nearby robot. With comparison among basic $RRT^*$, informed $RRT^*$ and the proposed $RRT^*$ in online motion planning, the proposed $RRT^*$ showed the best result by representing the closest solution to optimum.

• 한국정보통신학회논문지
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• 제22권9호
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• pp.1172-1178
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• 2018

손동작 인식을 통하여 컴퓨터 프레젠테이션을 제어하는 시스템을 제안한다. 제안하는 시스템은 손 동작의 다양한 운동 형태를 인식, 구분함으로써 부가적인 제어용 장치 없이 프레젠테이션을 제어한다. 손동작의 인식을 위하여 얼굴영역 검출과 손영역 검출을 시행한다. 하르분류기(Haar classifier)를 이용하여 얼굴영역을 검출하며, HSV 컬러모델상에서 피부 색상 정보에 따라 손영역을 검출한다. 얼굴 영역은 손동작의 시작과 끝, 동작의 크기 및 방향을 판단하는 기준으로 삼는다. 얼굴 영역으로부터 가로, 세로 중심축을 설정하고 제안하는 모션 식별룰에 따라 다양한 손동작을 인식하고 컴퓨터 제어에 이용한다. 약 1200회의 동작 인식 실험에서 97.2%의 인식률을 얻어 제안하는 알고리즘이 유효함을 확인하였다.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제7권6호
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• pp.549-558
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• 2001

동작 포착 시스템에 의해 기록된 동작 데이타를 재사용하는 것은 비용 절감이나 작업과정의 효율성 증대를 위해 매우 중요한 기술이다. 그러나 기록된 데이타의 동작 곡선이 제어점을 가지고 있지 않기 때문에 상호작용을 통한 동작 데이타의 편집이 쉽지 않아서 데이타의 재사용에 어려움이 있다. 기존 동작 데이타를 재사용하는 기술로서 많은 학자들은 조각 동작(Clip motion)들을 부드럽게 연결하여 새로운 동작을 만들어 내는 동작 전이 기술을 제안하고 있다. 본 논문에서는 이러한 동작 전이 기술의 구현 방법으로 균등 자세 지도(Uniform Posture Map: UPM)알고리즘을 제안한다. 학습 단계에서 UPM은 다관절체의 다양한 자세들을 비감독 경쟁 학습을 통해 양자화한다. 이 단계에서 서로 유사한 자세를 나타내는 출력 뉴런을 기하학적으로 근접한 위치에 배치해서 다관절체의 전체 동작 지도를 생성한다. 생성된 UPM의 이러한 특징을 이용해서 적용된 두 동작의 중간 자세를 만들어 내고, 이 자세를 전체 중간 동작을 만들어 내는 키 프레임으로 사용한다. 많은 계산량이 요구되며, 결과 동작을 제어하기가 어려운 다른 동작 전이 알고리즘들과 비교하여 UPM 알고리즘은 중간 동작 생성에 상대적으로 적은 계산량을 요구하며, 하나의 변수를 이용하여 생성된 동작을 제어할 수 있어서 편리한 상호작용 작업 환경을 제공한다. 특히 자기 조직 지도(Self-Organizing Mpa: SOM) 알고리즘을 이용해 자세 지도를 생성할 때, 실제로 존재하지 않은 자세가 포함될 수 있는 가능성을 학습 단계에서 제거함으로써 자세 생성에 있어서 안정성을 확보할 수 있다. 이로 인해 선형 보간법에 비해서 실제 동작에 가까운 동작 곡선을 생성함으로써 보다 자연스러운 동작을 만들어 낼 수 있다. 본 논문에서 제안된 동작 전이 기법은 삼차원 애니메이션 제작, 삼차원 게임, 가상 현실 등의 다양한 분야에 유용하게 적용될 수 있다.

• 한국의류산업학회지
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• 제24권3호
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• pp.333-345
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• 2022

This study developed and evaluated the motion control of 3D printed fingers applied to smart gloves. Four motions were programmed by assembling the module using the Arduino program: cylindrical grasping, spherical grasping, tip-to-tip pinch gripping, and three-jaw pinch gripping. Cap and re-entrant (RE) strip types were designed to model the finger. Two types of modeling were printed using filaments of thermoplastic elastomer (TPE) and thermoplastic polyurethane (TPU). The prepared samples were evaluated using three types of pens for cylidrical grasping, three types of balls for spherical grasping, and two types of cards for tip-to-tip pinch gripping and three-jaw pinch gripping. The motion control of fingers was connected using five servo motors to the number of each control board. Cylindrical and spherical grasping were moved by controlling the fingers at 180° and 150°, respectively. Pinch gripping was controlled using a tip-to-tip pinch motion controlled by the thumb at 30° and index-middle at 0° besides a three-jaw pinch motion controlled by the thumb-index finger-middle at 30°, 0°, and 0°, respectively. As a result of the functional evaluation, the TPE of 3D-printed fingers was more flexible than those of TPU. RE strip type of 3D-printed fingers was more suitable for the motion control of fingers than the 3D-printed finger.