• Journal of the Korean Home Economics Association
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• v.29 no.2
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• pp.17-34
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• 1991

The purpose of this study was to find out problems which occured between clothes and motor ability traits of the hemiplegic aged. The samples were 32 hemiplegic aged men and were compared with 43 healthy aged men. Motor ability of the samples were measured by ROM test, muscle power test and finger function test(grip strength, hand's coordination, lateral pinch, 3pt. pinch). Design of the clothes consisted of 25 variables and the analysis of dressing and undressing motion consist of 10 motions of dressing and undressing dress shirts and 8 motions of trousers. The results were as follows: 1. There were significant relationship between ROM and muscle power and finger function of the hemiplegic aged(P<.001). 2. There were significant differences between the nomal side's finger function of the hemiplegic aged and that of the healthy group(P<.001). 3. The designs of clothes such as tutle neck line, long sleeve, button cuffs, fastening lace, open zipper and belt of trousers gave much difficulty to the hemiplegic when dressing and undressing. 4. The most difficult motion of dressing and undressing was fastening when dressing both dress shirts and trousers. 5. There were partly significant relationship between design of clothes and ROM, muscle power, finger function of hemiplegic aged man. 6. There were partly significant relationship between the degree of difficulty in dressing and undressing motions and ROM, muscle power, finger function of hemiplegic aged man.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2000.04a
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• pp.109-112
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• 2000

The purpose of the present study is to evaluate the basic upper-limb involved in products manipulation. Upper-limb muscular deformations and electromyography (EMG) measurements are used as indexes for estimated motion: hand opening and closing, wrist extending and flexing, pronation and supination, grasping conditions. Measured values are analyzed by multivariate analysis and a regression equation is obtained for estimating the characteristics of upper-limb performance. Muscular deformation is defined as a change in shape, such as a pressure changes when the hand or wrist moves. hand opening and closing can be discriminated at a higher percentage of accuracy by muscular deformation data than by EMG data. Muscular deformation measurements using air-pack pressure sensors were verified to be effective in motion estimation applications.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2001.11a
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• pp.76-80
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• 2001

The weight of shoes may serve as a determining factor of perceived comfort and feel to the consumer in their purchase and repurchase decisions of footwear. People, however, seem to have trouble in accurately judging the feeling of weight of shoes on their feet. This paper made a psychophysical study of subjects′ sensitivity to weight on their feet and in their hands. The experiment consisted of 3 tests according to the motions people make when they evaluate the feel of shoes: 1) vertical lifting of a shoe on the foot ("hefting" in on the foot) 2) swing the shod foot back and forth; 3) holding and lifting a shoe by hand ("hefting" it in the hand). The method of constant stimuli and magnitude estimation were used for the experiment with 20 subjects. Weber′s ratios and the power law exponents obtained for each of the three tests were 0.156 and 0.713, 0.108 and 0.970, and 0.065 and 1.249, respectively in the same order of the previously listed tests.

• Journal of Internet Computing and Services
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• v.15 no.4
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• pp.33-42
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• 2014

Hand-signal is an effective communication means in the situation where voice cannot be used for expression especially for soldiers. Vision-based approaches using cameras as input devices are widely suggested in the literature. However, these approaches are not suitable for soldiers that have unseen visions in many cases. in addition, existing special-glove approaches utilize the information of fingers only. Thus, they are still lack for soldiers' hand-signal recognition that involves not only finger motions, but also additional information such as the rotation of a hand. In this paper, we have designed and implemented a new recognition system for six military hand-signal motions, i. e., 'ready', 'move', quick move', 'crawl', 'stop', and 'lying-down'. For this purpose, we have proposed a finger-recognition method and motion-recognition methods. The finger-recognition method discriminate how much each finger is bended, i. e., 'completely flattened', 'slightly flattened', 'slightly bended', and 'completely bended'. The motion-recognition algorithms are based on the characterization of each hand-signal motion in terms of the three axes. Through repetitive experiments, our system have shown 91.2% of correct recognition.

• Journal of Biomedical Engineering Research
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• v.37 no.3
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• pp.105-111
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• 2016

Introduction: Surgical robot is the alternative instrument that substitutes the difficult and precise surgical operation; should have intuitiveness operationally to transfer natural motions. There are limitations of hand motion derived from contacting mechanical handle in the surgical robot master interface such as mechanical singularity, isotropy, coupling problems. In this paper, we will confirm and verify the feasibility of intuitive Non-restraint master interface which tracking the hand motion using infra-red camera and only 3 reflective markers without the hardware handle for the surgical robot master interface. Materials & methods: We configured S/W and H/W system; arranged 6 infra-red cameras and attached 3 reflective markers on hands for measuring 3 dimensional coordinate then we find the 7 motions of grasp, yaw, pitch, roll, px, py, pz. And we connected Virtual-Master to the slave surgical robot(Laparobot) and observed the feasibility. To verify the result of motion, we compare the result of Non-restraint master and that of clinometer (and protractor) through measuring 0~180 degree, 10degree interval, 1000 samples and recorded standard deviation stands for error rate of the value. Results: We confirmed that the average angle values of Non-restraint master interface is accurately corresponds to the result of clinometer (and protractor) and have low error rates during motion. Investigation & Conclusion: In this paper, we confirmed the feasibility and accuracy of 3D Non-restraint master interface that can offer the intuitive motion of non-contact hardware handle. As a result, we can expect the high intuitiveness, dexterousness of surgical robot.

• Journal of Industrial Technology
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• v.21 no.B
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• pp.265-272
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• 2001

The human arm is modeled by three rigid bodies(the upper arm, the forearm and the hand)with seven degree of freedom(three in the shoulder, two in the elbow and two in the wrist). The objective of this work is to present a method to determine the three-dimensional kinematics of the human elbow joint using a magnetic tracking device. Euler angle were used to determine the elbow flexion-extension, and the pronation-supination. The elbow motion for the various driving conditions is measured through the driving test using a simulator. Discomfort levels of elbow joint motions were obtained as discomfort functions, which were based on subjects' perceived discomfort level estimated by magnitude estimation. The results showed that the discomfort posture of elbow joint motions occurred in the driving motion.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.3
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• pp.130-138
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• 1993

A mechanism for collision detection in general animation system is necessary to prevent the interpenetration among multiple objects. On the other hand, a dynamic simulation system which is a part of animation system simulates realistic motions using dynamics after the collision, which is called collision response. In this paper, a method for reducing the CPU time for collision detection by removing redundant calculations and object sorting is proposed. A dynamic simulation system including collision detection and response function was implemented to demonstrate the proposed methods, where the input data as elasticity, friction, gravity, object shape, external force and external torque are given by the user. The system simulates motions of multiple objects using dynamics, and generates the wireframe display.

• Journal of Magnetics
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• v.22 no.1
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• pp.155-161
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• 2017

This paper presents a new nonmechanical rehabilitation system driven by magnetic force. Typically, finger rehabilitation mechanisms are complex mechanical systems. The proposed method allows wireless operation, a simple configuration, and easy installation on the hand for active actuation by magnetic force. The system consists of a driving coil, driving magnets (M1), and auxiliary magnets (M2 and M3), respectively, at the finger, palm, and the center of coil. The magnets and the driving coil produce three magnetic forces for an active motions of the finger. During active actuations, magnetic attractive forces between M1 and M2 or between M1 and M3 enhance the flexion/extension motions. The proposed system simply improves the extension motion of the finger using a magnetic system. In this system, the maximum force and angular variation of the extension motion were 0.438 N and $49^{\circ}$, respectively. We analyzed the magnetic interaction in the system and verified finger's active actuation.

• The Journal of Korea Robotics Society
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• v.17 no.3
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• pp.347-352
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• 2022

The paper presents how to update impedance control parameters for dual-arm manipulators using EMG signals and motions of the operator. Since the hand motions of the dual-arm are modeled to be the mass-spring-damper system in this paper, the impedance parameter update method is an important issue to reflect the operator's force. However, task space inertia to be used as the mass parameter goes to infinity if the manipulator approaches a kinematic singularity. To alleviate this issue, the impedance (stiffness and damping) parameters are divided with a diagonal element of the task space inertia. Also, the stiffness and damping matrices are updated using the normalized EMG signals captured from the operator's forearm. Through this process, the motion of the dual-arm manipulator is more stabilized even though it approaches the kinematic singularity.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.47.3-47.3
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• 2019

In this talk, we present numerical simulations of driven hydrodynamic and magnetohydrodynamic (MHD) turbulence with weak/strong imposed magnetic fields. We mainly focus on turbulence driven compressively (∇ × f = 0). Our main goal is to examine how magnetic fields play a role in generating solenoidal modes in compressive turbulence. From our simulation analysis, we find that solenoidal energy densities in hydrodynamic and weak magnetic field cases are generated up to ~ 30% of total ones. On the other hand, in the case of strong magnetic fields, solenoidal energy densities are excited up to ~ 70%. To interpret the results, we further analyze vorticity (w = ∇ × u) equation and find that magnetic fields directly create solenoidal motions, and magnetic tension is most effective in this sense. In hydrodynamic simulations, however, we find that viscous dissipation provides vorticity seeds at the very early stage and they are amplified via stretching process. Lastly, in weak magnetic fields cases, we find that solenoidal motions are created by the effects of magnetic fields, viscosity, and stretching in conjunction.