• Korean Journal of Applied Biomechanics
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• v.15 no.4
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• pp.85-95
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• 2005

The purpose of this study was to investigate the relations between the segments of the body, the three dimensional anatomical angle during One Hand Backhand Stroke and Two Hand Backhand in tennis. For the movement analysis three dimensional cinematographical method(APAS) was used and for the calculation of the kinematic variables a self developed program was used with the LabVIEW 6.1 graphical programming(Johnson, 1999) program. By using Eular's equations the three dimensional anatomical Cardan angles of the joint and racket head direction were defined. 1. In three dimensional maximum linear velocity of racket head the X axis and Y axis(horizontal direction) showed $-11.04{\pm}2.69m/sec$, $-9.31{\pm}0.49m/sec$ before impact, the z axis(vertical direction) maximum linear velocity of racket head did not show at impact but after impact this will resulted influence upon hitting ball. It could be suggest that Y axis velocity of racket head influence on ball direction and z axis velocity influence on ball spin after impact. The stance distance between right foot and left foot was mean $75.4{\pm}5.86cm$ during one hand backhand stroke and $72.6{\pm}4.67cm$ during two hand backhand stroke. 2. The three dimensional anatomical angular displacement of trunk in interna rotation-external rotation showed most important role in backhand stroke. and is follwed by flexion-extension. the three dimensional anatomical angular displacement of trunk did not show significant difference between one hand backhand stroke and two hand backhand stroke but the three dimensional anatomical angular displacement of trunk was bigger than one hand backhand stroke. 3. while backhand stroke, the flexion-extension and adduction-abduction of right shoulder joint showed significant different between one hand backhand stroke and two hand backhand stroke. the three dimensional anatomical angular displacement of right shoulder joint showed more flex and abduct in one hand backhand stroke. 4. The three dimensional anatomical angular displacement of left shoulder showed flexion, adduction, and external rotation at impact. after impact, The angular displacement as adduction-abduction of left shoulder changed motion direction as abduction. angular displacement of left shoulder as flexion-extension showed bigger than the right shoulder.

• Journal of The Korean Society of Integrative Medicine
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• v.3 no.4
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• pp.1-9
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• 2015

Purpose : We described how the training of non-dominant hand that applicates the activity effects on dominant hand. Method : From November 6th to December 2nd 2013, We randomly selected 18 people that don't have a damage of hand function and are in college of K in Busan. (cross stitch training group 9 people, control group 9 people) All participants agreed on the research after fully being aware of training procedures and spontaneously conducted. Each training was practiced for 40 minutes in once every second day. One researcher deals with three participants at silent environment. We used the study measurement, Purdue pegboard, to investigate the sharpness of hand. To investigate the advancement of hand function caused by cross stitch training, we practiced three times estimations of primary one before training, middle one after 2 weeks training, last one after four weeks training and obtained the following results. Result : First of all, We found that the group of hand training appeared to be advanced of dominant hand's sharpness depending on the training period more than the control group. Second, We found that the group of hand training appeared to be advanced of non-dominant hand's sharpness depending on the training period more than the control group. Third, We found that the group of hand training appeared to be advanced of both hand's sharpness depending on the training period more than the control group. Fourth, We found that the group of hand training appeared to be advanced of the assembling function sharpness depending on the training period more than the control group. Conclusion : Put the results of this research together, we found that non-dominant hand training that used the activity was of help to advance the function of dominant hand. So, we thinks that hand training might help the recovery of affected hand function to the person that have a problem of hand function like hemiplegia patient. It will be required to practice the further study targeting the person that have a problem of hand function like hemiplegia patient. We hope that this research will be apply to clinical occupational therapy.

• Journal of Korean Physical Therapy Science
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• v.9 no.2
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• pp.133-141
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• 2002

This purpose of this study was to design the effect of recovering of a hand amputees by Myoelectronic hand. It was designed with 2 degree of freedom in the laboratory. Myoelectronic hand had only one degree of freedom and one movement until now. Also this myoelectronic hand had multi-joint and it could move widely. Wire was used in transmission. Myoelectronic hand data was obtained by analyzing hand anatomically and measuring and that data was applied when it was designed. PID controller of Myoelectronic hand was used to it. Displacement control was applied the first link. Experiment was accomplished in Tip grasp, Power grasp and Hook grasp modes. Displacement control was good in low frequency. Velocity control was applied to each mode. The objective of the study was to develop more better multifunction myoelectronic control strategies. A myoelectronic hand with a hand amputees could do some jobs such as grasping materials, lifting weighting, holding cup and etc. As a result of this study, all subjects with hand amputees significantly improved in ADL. Further studies were needed to evaluate the effect of a myoelectronic hand with more precise laboratory equipment.

• Journal of the Korean Society of Physical Medicine
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• v.13 no.1
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• pp.1-9
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• 2018

PURPOSE: This study investigated the neurophysiological and behavioral adaptation during one or both hands movement in chronic stroke patients. METHODS: The study included sixteen hemiplegic stroke patients. Neurophysiological data (brain activation and muscle activation) were examined by electroencephalography (EEG) and electromyography (EMG), and behavioral adaptation was examined by wrist extension angle during wrist extension with one hand or both hands. Outcome variables of one hand or both hands were; mu rhythm of the EEG, EMG amplitude of wrist extensor and flexor muscles, and wrist angle of Myomotion 3D motion analysis. RESULTS: Our results revealed that wrist extension angle was significant increased during both hands movement compared to one hand movement (p<.05). Furthermore, in affected sensorimotor area, there was significant increase in the brain activation during both hands movement compared to one hand movement (p<.05). However, there was no significant different between one hand and both hands movement in muscle activation (p>.05). CONCLUSION: According to the findings of this experiment, bilateral arm movement improved brain activity on affected sensorimotor area and wrist extension angle. Therefore, we suggest that bilateral arm movement would positive effect on stroke rehabilitation in terms of increase in brain activation on affected motor area and wrist extension during bilateral arm movement.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.596-601
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• 2000

In a robot/vision system, the vision sensor, typically a CCD array sensor, is mounted on the robot hand. The problem of determining the relationship between the camera frame and the robot hand frame is refered to as the hand-eye calibration. In the literature, various methods have been suggested to calibrate camera and for sensor registration. Recently, one-step approach which combines camera calibration and sensor registration is suggested by Horaud & Dornaika. In this approach, camera extrinsic parameters are not need to be determined at all configurations of robot. In this paper, by modifying the camera model and including the lens distortion effect in the perspective transformation matrix, a new one-step approach is proposed in the hand-eye calibration.

• Journal of Korea Game Society
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• v.16 no.6
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• pp.49-58
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• 2016

This paper proposes three schemes of one-hand control that can be used in the First-Person Viewpoint mobile games and evaluates them. Displaying virtual controllers on the screen, the existing mobile games use schema that allows users use both hands. In the First-Person Viewpoint mobile games, however, one-hand control is possible because smaller number of functions for viewpoint movement is required. This research proposes three one-hand control schemes for First-Person Viewpoint movement and rotation, and evaluates them using AHP. The experiment results prove that one-hand control schemes are more useful than both-hands control schemes for the mobile game users.

• Journal of the Ergonomics Society of Korea
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• v.31 no.4
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• pp.551-556
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• 2012

Objective: This study presents the effect of visual feedback on one-hand gesture performance in vision-based gesture recognition system when people use gestures to control a screen device remotely. Backgroud: gesture interaction receives growing attention because it uses advanced sensor technology and it allows users natural interaction using their own body motion. In generating motion, visual feedback has been to considered critical factor affect speed and accuracy. Method: three types of visual feedback(arrow, star, and animation) were selected and 20 gestures were listed. 12 participants perform each 20 gestures while given 3 types of visual feedback in turn. Results: People made longer hand trace and take longer time to make a gesture when they were given arrow shape feedback than star-shape feedback. The animation type feedback was most preferred. Conclusion: The type of visual feedback showed statistically significant effect on the length of hand trace, elapsed time, and speed of motion in performing a gesture. Application: This study could be applied to any device that needs visual feedback for device control. A big feedback generate shorter length of motion trace, less time, faster than smaller one when people performs gestures to control a device. So the big size of visual feedback would be recommended for a situation requiring fast actions. On the other hand, the smaller visual feedback would be recommended for a situation requiring elaborated actions.

• The Journal of Korea Robotics Society
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• v.17 no.3
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• pp.322-333
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• 2022

The Avatar robot, which is one of the teleoperation robots, aims to enable users to feel the robot as a part of the body to intuitively and naturally perform various tasks. Considering the purpose of the avatar robot, an end-effector identical to a human hand is advantageous, but a robotic hand with human hand level performance has not yet been developed. In this paper we propose a new 3-finger robotic hand with human-avatar hand posture mapping algorithm which were integrated with TOCABI-AVATAR, one of the teleoperation system. Due to the flexible rolling contact joints and tendon driven mechanism applied to the finger, the finger could implement adaptive grasping and absorb the impact force caused by unexpected contacts. In addition, human-avatar hand mapping algorithm using five calibration hand postures propose to compensate physical differences between operators. Using the TOCABI-AVATAR system with the robotic hands and mapping algorithm, the operator can perform 13 out of 16 hand postures of grasping taxonomy and 4 gestures. In addition, using the system, we participated in the ANA AVATAR XPRIZE Semi-final and successfully performed three scenarios which including various social interactions as well as object manipulation.

• Journal of the Ergonomics Society of Korea
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• v.30 no.2
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• pp.365-373
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• 2011

The existing GOMS model overestimates the performance time of mouse activities because it describes them in a serial sequence. However, parallel movements of eye and hand(eye-hand coordination) have been dominant in mouse activities and this eye-hand coordination is the main factor for the overestimation of performance time. In this study, therefore, the revised CGOMSL model was developed to implement eye-hand coordination to the mouse activity to overcome one of the limitations of GOMS model, the lack of capability for parallel processing. The suggested revised CGOMSL model for drag activity, as an example for one of mouse activities in this study, begins visual search processing before a hand movement but ends the visual search processing with the hand movement in the same time. The results show that the revised CGOMSL model made the prediction of human performance more accurately than the existing GOMS model. In other words, one of the limitations of GOMS model, the incapability of parallel processing, could be overcome with the revised CGOMSL model so that the performance time should be more accurately predicted.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.53
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• pp.1-12
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• 1999

A warranty cost analysis for new products have received a lot of attention. In contrast, there is hardly any literature on similar analysis for second-hand products. The market of second-hand products has been increasing and along with that the importance of warranties for second-hand products has also been increasing. However, warranty policies similar to new products are not economically acceptable to dealers. One needs to formulate new warranty policies and models to estimate expected warranty costs for second-hand products. This paper proposes one-dimensional cost sharing warranty policies and develops models at system level to analysis warranty cost for second-hand products sold with these policies.