• Journal of Biomedical Engineering Research
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• v.24 no.2
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• pp.133-140
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• 2003

In this study, muscle activity was measured using surface EMG (sEMG) during a voluntary maneuver (ankle dorsiflexion) in the supine position was compared pre and post gait training. Nine patients with incomplete spinal cord injury participated in a supported treadmill ambulation training (STAT), twenty minutes a day, five days a week for three months. Two tests, a gait speed test and a voluntary maneuver test, were made the same day, or at least the same week, pre and post gait training. Ten healthy subjects' data recorded using the same voluntary maneuvers were used for the reference. sEMG measured from ten lower limb muscles was used to observe the two features of amplitude and motor control distribution pattern, named response vector. The result showed that the average gait speed of patients increased significantly (p〈0.1) from 0.47$\pm$0.35 m/s to 0.68$\pm$0.52 m/s. In sEMG analysis, six out of nine patients showed a tendency to increase the right tibialis anterior activity during right ankle dorsiflexion from 109.7$\pm$148.5 $mutextrm{V}$ to 145.9$\pm$180.7 $mutextrm{V}$ but it was not significant (p〈0.055). In addition, only two patients showed increase of correlation coefficient and total muscle activity in the left fide during left dorsiflexion. Patients' muscle activity changes after gait training varied individually and generally depended on their muscle control abilities of the pre-STAT status. Response vector being introduced for quantitative analysis showed good Possibility to anticipate. evaluate, and/or guide patients with SCI, before and after gait training.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.10
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• pp.4459-4466
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• 2011

The purpose of this study was to compare the lower extremity muscle activities according to the different longitudinal arch and treadmill inclination and to provide basic data on treadmill walking exercise. The selected 17 subjects who had not lower extremity injury and ROM limitation were recruited in this study. The longitudinal arch was divided into normal foot and flat foot. The inclinations of the treadmill were $0^{\circ}$, up hill $5^{\circ}$, $10^{\circ}$, $15^{\circ}$, down hill $5^{\circ}$, $10^{\circ}$ and $15^{\circ}$. The electromyography was used to analyze the muscle activity of rectus femoris, biceps femoris, tibialis anterior, gastrocnemius lateralis and medialis. There were significant differences between the inclination $0^{\circ}$ and down hill $15^{\circ}$. There was no interactive effect of treadmill inclination on the longitudinal arch. The activity difference of lower extremity muscle was not conspicious. There existed the interactive effect between the longitudinal arch and muscle activity. The contrast test within subjects showed positively in the rectus femoris and gastrocnemius medialis, biceps femoris and gastrocnemius medialis. The different longitudinal arch did not influence on the effect(p>.05). There was significant difference between the normal foot and the flat foot. So it is necessary to carry out the long term study.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.5
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• pp.117-132
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• 2022

The purpose of this study is to analyze factors that affect road users' acceptance of fully autonomous vehicles (level 4 or higher). A survey was done with drivers of general cars and pedestrians who share roads with fully autonomous vehicles. Five acceptability factors were selected: trust towards technology, compatibility, policy, perceived safety, and perceived usefulness. The effect on behavioral intention was analyzed using structural equation modeling (SEM). The perceived safety and trust towards technology were found to be very important in the acceptance of fully autonomous vehicles, regardless of the respondent, and policy was not influential. Compatibility and perceived usefulness were particularly influential factors for drivers. In order to improve the acceptance by road users, securing technical completeness of fully autonomous vehicles is important. Certification and evaluation of the safe driving ability of fully autonomous vehicles should be thoroughly performed, and based on the results, it is necessary to improve the perception by road users. It is necessary to positively recognize fully autonomous vehicles through education and publicity for road users and to support their smooth interaction.

• The Journal of the Korea Contents Association
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• v.20 no.9
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• pp.486-493
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• 2020

The purpose of this study was to identify the effects of an exercise program for lumbar stabilization on static and dynamic balancing and gait of stroke patients. The subjects were 27 stroke patients, who were divided into an experimental group(n=14) and a control group(n=13). The exercise was conducted for 30 minutes a day, four times a week, and for six weeks. The variables included static and dynamic standing balance and gait, which were verified before and after the lumbar stabilization exercise. Using the IBM SPSS(19.0 version), data were analyzed with t-test and two-way ANOVA to validate the differences before and after the experiment and between the groups. The significance level was set at α = .05 and the results of this study are as follows. First, statistically significant differences were found in the static standing balance after the exercise (P< .05). Second, there were statistically significant differences in the dynamic standing balance after the exercise (P< .05). Third, statistically significant differences were found in the gait of the patients after the exercise (P< .05). In addition, the interactions between the two groups showed significant differences. These results suggest that stroke patients need a variety of lumbar exercises and that the lumbar stabilization exercise can improve physical treatment and health of the patients, having positive effects on their quality of life. Further studies are necessary to explore the applications of various lumber exercises.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.5
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• pp.15-27
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• 2022

An omnidirectional VR treadmill is a highly-immersive walking simulator that allows identical body movements, such as walking, running, and sitting. However, the operation difficulty of an omnidirectional VR treadmill may cause data reliability problems. Therefore, this study aims to verify the effectiveness of a VR treadmill by comparing the ability to orient in the real and virtual worlds spatially. For this purpose, a rotating and searching path experiment was conducted with participants. This experiment showed that there was no statistically significant difference in the ability of the participants to orient in the real and virtual worlds spatially. In addition, the omnidirectional VR treadmill requires an adaptation time for the users due to the difficulty in the treadmill operation. However, there was no significant difference in the difficulty felt by the participants according to the adaptation time. Hence, these findings supported the possibility of collecting realistic walking data without safety concerns through an omnidirectional VR treadmill. Furthermore, this treadmill could be used in future research to solve problems directly related to pedestrian safety, such as the interaction between vehicles and pedestrians.

• Journal of Korea Entertainment Industry Association
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• v.8 no.2
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• pp.283-297
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• 2014

The future of human life is expected to be innovative by increasing social, economic, political and personal, including all areas of life across the multi-disciplinary skills. Particularly, in the field of robotics and next-generation games with robots, by multidisciplinary contributions and interaction, convergence between technology is expected to accelerate more and more. The purpose of this study is that by new interface model beyond the technical limitations of the "human-robot interface technology," until now and time and spatial constraints and through fusion of various modalities which existing human-robot interface technologies can't have, the research of more reliable and easy free "human-robot interface technology". This is the research of robot game system which develop and utilizing real time synchronization engine linking between biped humanoid robot and the behavior of the position value of mobile device screen's 3D content (contents), robot (virtual robots), the wireless protocol for sending and receiving (Protocol) mutual information and development of a teaching program of "Direct Teaching & Play" by the study for effective teaching.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1349-1357
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• 2019

The purpose of this study was to investigate to effect of core exercise with swiss ball on sarcopenia index in agriculture older women. A total of 30 subjects(15 Ex group, 15 Con group, 65 over agriculture older woman) were participated in this study. Intervention group were assigned to performing a progressive core exercise training program for 12 weeks(2 time/week). Dependent variable were grip strength, chair stand, muscle mass, 4m gait speed, Timed up and go, and 400m walking. As a result were following. Grip strength was not significantly difference but chair stand was significantly difference in time. And muscle mass was significantly difference in groups. And 4m gait speed, Timed up and go and 400m walking were significantly difference in time. In conclusion, lower body muscle strength and short physical performance battery by muscle activating with core muscle strength training.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.6
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• pp.75-83
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• 2007

A model based approach of tracking the limbs of a walking human subject is proposed in this paper. The tracking process begins by building a data base composed of conditional probabilities of motions between the limbs of a walking subject. With a suitable amount of video footage from various human subjects included in the database, a probabilistic model characterizing the relationships between motions of limbs is developed. The motion tracking of a test subject begins with identifying and tracking limbs from the surveillance video image using the edge and silhouette detection methods. When occlusion occurs in any of the limbs being tracked, the approach uses the probabilistic motion model in conjunction with the minimum cost based edge and silhouette tracking model to determine the motion of the limb occluded in the image. The method has shown promising results of tracking occluded limbs in the validation tests.

• Journal of Life Science
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• v.19 no.10
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• pp.1368-1373
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• 2009

The purpose of this study was to assess the influence of waist size on the reliability and validity of pedometers to count steps in children and youth. The participants for this study were 20 children and youth, composed of 14 Hispanic and 6 Caucasian children. Ten children and youth had waist circumferences greater than the $85^{th}$ percentile (Body Mass Index (BMI)=$28.91\pm3.07$), and 10 children and youth had waist circumferences smaller than the $50^{th}$ percentile (BMI=$18.05\pm1.55$). To examine pedometer reliability, each child completed 3 ascent and descent trials up a set of 15 stairs while wearing a Yamax SW-701 pedometer. The main effect of trials was not statistically significant for the stair ascent trials F (2, 36)=2.575 or for the descent trials F (2, 36)=0.235. The trial by group interaction was also not statistically significant. To examine the influence of waist circumference on the validity of the pedometer in counting walking steps at a self-selected walking pace, the children and youth in the two groups completed a 400-m course. The main effect on the groups was statistically significant, F (1, 18)=7.489. The main effect of counting techniques was not statistically significant, F (1, 18)=2.983 (hand-counted vs. pedometer counted). Overall, the trial and trial by group interaction comparisons for the 400-m walk were not statistically significant, suggesting that the pedometer was equally valid as a tool for assessing walking steps in high waist circumference (HWC) and low waist circumference (LWC) in children and youth.

• Journal of KIISE:Computing Practices and Letters
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• v.12 no.6
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• pp.358-366
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• 2006

This paper describes a novel navigation algorithm using a locomotion interface with two 6-DOF programmable foot platforms. When a human walks on the locomotion interface (LI), the walking motions of the human are recognized by several sensors. Then, the sensed information is used by the LI for generation of infinite surfaces for continuous walking and the virtual environments for scene update according to motions of the human walking. The suggested novel navigation system can induce user's real walking and generate realistic visual feedback during navigation. A novel navigation algorithm is suggested to allow natural navigation in virtual environments by utilizing conditions of normal gait analysis. For realistic visual feedback, the virtual environment is designed with three components; 3D object modeler for buildings and terrains, scene manager and communication manager component. From experiments, the subjects were satisfied with the reality of the suggested navigation algorithm using the locomotion interface. Therefore, the suggested navigation system can allow a user to explore into various virtual terrains with real walking and realistic visual feedback.