• 제어로봇시스템학회:학술대회논문집
• /
• 1993.10b
• /
• pp.212-217
• /
• 1993

In this paper, characteristics of the motions of a human arm are investigated experimentally. When the conditions of the target point are restricted, human adjusts its trajectory and velocity pattern of the arm to fit the conditions skillfully. The purpose of this work is to examine the characteristics of the trajectory, velocity pattern, and the size of the duration in the following cases. First, we examine the case of point-to-point motion. The results are consistent with the minimum jerk theory. However, individual differences in the length of the duration can be observed in the experiment. Second, we examine the case which requires accuracy of positioning at the target point. It is found that the velocity pattern differs from the bell shaped pattern explained by the minimum jerk theory, and has its peak in the first half of the duration. When higher accuracy of the positioning is required, learning effects can be observed. Finally, to examine the case which requires constraint of the arm posture at the target point, we conduct experiments of a human trying to grasp a cup. It is considered that this motion consists of two steps : one is the positioning motion of the person in order to start the grasping motion, the other is the grasping motion of the human's hand approaching toward the cup and grasping it. In addition, two representative velocity patterns are observed : one is the similar velocity pattern explained in the above experiment, the other is the velocity pattern which has its relative maximum in the latter half of the duration.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.19 no.5
• /
• pp.826-841
• /
• 1995

This study is concerned with the functional utility of movement in sleeve from an ergonomic viewpoint. Experiments were carried out which include 43 upper extremity segments, 21 motions and 35 female subjects. The major conclusions of the study are. 1. The expansion rate of upper extremity was higher in length than in circumference mesurements. The amounts of expansion were, especially high (more than 60mm) for inner arm length, axillary arm circumference, and outer arm length. Therefore, a lot of ease is necessary for these parts. On the other hand, armhole circumference, forearm circumference, and wrist circumference had low rates of expansion. The sleeve cap length was also contracted in all motions. 2. The expansion rate and the range of expansion and contraction were higher in the upper arm than in the forearm. The main points of expansion were the axillary and elbow parts. The segment of maximum expansi (rate of 44.8%) was Iii of axillary parts. As the body surface expands mainly in some segments, it is desirable to allow ease to the main segments of expansion. 3. In a basic sleeve, necessary ease was lacking in the measurements for outer arm length and axillary arm circumference, while it was too large in armhole circumference, forearm circumference, wrist circumference, and sleeve cap length. Therefore, a basic sleeve is inadequate as a functional sleeve for hard work in point of functional utility of movement. Wider application of these findings would lead to an improvement in the comfort of workers.

• Journal of Korea Multimedia Society
• /
• v.19 no.1
• /
• pp.60-67
• /
• 2016

PC users have long been controlling their computers using input devices such as mouse and keyboard. To improve inconveniences of these devices, the method of screen-touching has widely been used these days, and devices recognizing human gestures are being developed one after another. Fox example, Kinect, developed and distributed by Microsoft, is a non-contact input device that recognizes human gestures through motion-recognizing sensors, thus replacing the mouse as an input device. However, when controlling the mouse on a large screen, it suffers from the problem of requiring large motions in order to move the mouse pointer to the edges of the screen. In this paper, we propose a joystick-driven mouse-controlling method which enables the user to move the mouse pointer to the corners of the screen with small motions. The experimental results show that movements of the user's palm within the range of 30 cm ensure movements of the mouse pointer to the edges of the screen.

• Journal of the Korean Society for Railway
• /
• v.13 no.3
• /
• pp.283-289
• /
• 2010

Recent advance of digital camera results in that image signal processing techniques are widely adopted to railroad security management. However, due to the nature of railroad management many images are acquired in low light level environment such as night scenes. The lack of light causes lots of noise in the image, which degrades image quality and causes errors in the next processes. 3D noise reducing techniques produce better results by using consecutive sequence of images. On the other hand, they cause degradation such as motion blur if there are motions in the sequence. In this paper, we use an adaptive weight filter to estimate more accurate motions and use the result of the adaptive filter to 3D result to improve objective and subjective mage quality.

• The Journal of Korea Robotics Society
• /
• v.14 no.3
• /
• pp.228-235
• /
• 2019

This paper presents a multiple DoFs (degrees-of-freedom) prosthetic forearm and sEMG (surface electromyogram) pattern recognition and motion intent classification of forearm amputee. The developed prosthetic forearm has 9 DoFs hand and single-DoF wrist, and the socket is designed considering wearability. In addition, the pattern recognition based on sEMG is proposed for prosthetic control. Several experiments were conducted to substantiate the performance of the prosthetic forearm. First, the developed prosthetic forearm could perform various motions required for activity of daily living of forearm amputee. It was able to control according to shape and size of the object. Additionally, the amputee was able to perform 'tying up shoe' using the prosthetic forearm. Secondly, pattern recognition and classification experiments using the sEMG signals were performed to find out whether it could classify the motions according to the user's intents. For this purpose, sEMG signals were applied to the multilayer perceptron (MLP) for training and testing. As a result, overall classification accuracy arrived at 99.6% for all participants, and all the postures showed more than 97% accuracy.

• ETRI Journal
• /
• v.45 no.6
• /
• pp.1079-1089
• /
• 2023

Stroke is one of the leading causes of long-term disability worldwide, placing huge burdens on individuals and society. Further, automatic human activity recognition is a challenging task that is vital to the future of healthcare and physical therapy. Using a baseline long short-term memory recurrent neural network, this study provides a novel dataset of stretching, upward stretching, flinging motions, hand-to-mouth movements, swiping gestures, and pouring motions for improved model training and testing of stroke-affected patients. A MATLAB application is used to output textual and audible prediction results. A wearable sensor with a triaxial accelerometer is used to collect preprocessed real-time data. The model is trained with features extracted from the actual patient to recognize new actions, and the recognition accuracy provided by multiple datasets is compared based on the same baseline model. When training and testing using the new dataset, the baseline model shows recognition accuracy that is 11% higher than the Activity Daily Living dataset, 22% higher than the Activity Recognition Single Chest-Mounted Accelerometer dataset, and 10% higher than another real-world dataset.

• Journal of Society of Preventive Korean Medicine
• /
• v.18 no.2
• /
• pp.115-123
• /
• 2014

Objective : The objective of this study is to develop a Qigong exercise program to reinforce musculoskeletal system of seniors appropriate for physical strength and conditions of seniors aged 65 years or above based on health Qigong exercise of oriental medicine. Method : Qigong exercise motions that can improve strength, muscular endurance, flexibility, and cardiovascular endurance of seniors were developed by primarily performing literature review of Qigong experts on the fields like oriental medicine, Qigong exercise, physical education and health science and secondarily using motion training for increased validity of motions. Results : The Qigong exercise program for musculoskeletal system of seniors was designed with 12 motions repeated 8 times and 20 minutes per session, including shoulder exercises (alternate turning of left and right shoulders, turning both arms back and forth, holding and lifting elbow to put it aside), waist exercises (wrapping the head with hands to bow, twisting waist while looking at the tip of hand, large spinning of ball, putting hands together to pull back), and knee exercises (going up a down while lifting a rock, balancing the body while lifting a knee, lifting and spreading knees while drawing circle with arms, raising both arms to the side while lifting heels, breathing). Conclusion : Once the effects of Qigong exercise for musculoskeletal system of seniors developed in this study are tested, the program is expected to contribute to development of Qigong exercise, a core part of oriental medicine health improvement project.

• Journal of Navigation and Port Research
• /
• v.29 no.8 s.104
• /
• pp.661-666
• /
• 2005

Recent warnings indicate that there is a potential risk of massive earthquake. These earthquakes could produce large-scale tsunamis. Consideration of the effect of Tsunami to the moored ship is very important bemuse it brings the loss of life and vast property damage in a viewpoint of ship operations within a harbor. If a tsunami occurs, a ship in a harbor may begin drifting in case of ship entering and departing harbor, and breakage of mooring rope and drifting of moored ship are happened. And extremely serious accident, such as stranding and collision to a quay, might occur. On the other hand, since the tsunami consists of approximately component waves of several minutes, there is a possibility of resonance with the long period motion of mooring vessel. As the speed of Tsunami is much faster than tidal current in a harbor, a strong resisting force might act on the moored ships. In this paper, the numerical simulation procedure in the matter of ship motions due to the attack of large-scale tsunamis are investigated and the effects on the ship motions and mooring loads are evaluated by numerical simulation.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.34 no.4
• /
• pp.399-405
• /
• 2010

The grasping motion of a person's hand for a simplified degree of freedom was modeled by using the photographic motion measured by a high-speed camera. The mathematical expression of distal interphalangeal (DIP) motion was developed by using relation models of the metacarpophalangeal (MCP) and proximal interphalangeal (PIP) motions to reduce the degree of freedom. The mathematical expression for humanoid-hand operation obtained using a learning algorithm with a neural network and using a kernel regression model were compared. A feasible model of hand operation was obtained on the basis of comparative data analysis by using the kernel regression model.

• Korean Journal of Applied Biomechanics
• /
• v.17 no.2
• /
• pp.177-185
• /
• 2007

Even though there were no clear definitions of the short game and short game distance, short game capability is crucial for a good golf score. Generally, chip shot and pitch shot are regarded as two principal components of the short game. Chip shot is a short, low trajectory shot played to the green or from trouble back into play. Pitch shot is a high trajectory shot of short length. Biomechanical studies were conducted usually to analyze full swing and putting motions. The purpose of the study was to reveal the kinematical differences between professional golfers' 30 yard $53^{\circ}wedge$ chip shot and $56^{\circ}wedge$ pitch shot motions. Fifteen male professional golfers were recruited for the study. Kinematical data were collected by the 60 Hz three-dimensional motion analysis system. Statistical comparisons were made by paired t-test, ANOVA, and Duncan of the SPSS 12.0K with the $\alpha$ value of .05. Results show that both the left hand and the ball were placed left of the center of the left and right foot at address. The left hand position of the chip shot was significantly left side of that of the pitch shot. But the ball position of the pitch shot was significantly right side of that of the chip shot. All body segments aligned to the left of the target line, open, at address. Except shoulder, there were no significant pelvis, knee, and feet alignment differences between chip shot and pitch shot. These differences at address seem for the ball height control. Pitch shot swing motions(the shoulder and pelvis rotation and the club head travel distance) were significantly bigger than those of the chip shot. Club head velocity of the pitch shot was significantly faster than that of the chip shot at the moment of impact. This was for the same shot length control with different lofted clubs. Swing motion differences seem mainly caused by the same shot length control with different ball height control.