• PNF and Movement
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• v.19 no.2
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• pp.261-267
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• 2021

Purpose: This study aimed to investigate changes in gait variables depending on whether a task was performed using a smartphone while walking on a ramp. Methods: The participants of this study were 41 college students attending U University located in Gyeongju City, Gyeongsangbuk-do. In this study, gait variables were measured during ramp gait while using a smartphone to perform a task and during ramp gait without performing such tasks. In other words, four walking conditions were used: 1) walking up a ramp, 2) walking up a ramp while using a smartphone to perform a task, 3) walking down a ramp, and 4) walking down a ramp while using a smart phone to perform a task. Gait variables were measured using a gait analysis tool (Legsys; BioSensics, USA), and stride time, stride length, stride velocity, cadence, and double support were analyzed. The order of measurements was randomized to control for order effects due to repeated measurements. Results: The comparative analysis of gait variables according to the presence or absence of smartphone use during ramp gait showed that there were significant differences in stride time, stride length, and stride velocity during both ramp ascent and ramp descent (p < 0.05). In both ramp ascent and ramp descent, stride time increased when walking using a smartphone, compared to when walking without using a smartphone (p < 0.05). However, in both ramp ascent and ramp descent, stride length and stride velocity were decreased when walking using a smartphone compared to when walking without using a smartphone (p < 0.05). Conclusion: The study results showed that the use of a smartphone during walking can affect safety. Therefore, it is necessary to improve the awareness of risks associated with walking while using a smartphone, and further research needs to be conducted in various environments and with different ramps.

• The Journal of the Korea Contents Association
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• v.7 no.5
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• pp.63-71
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• 2007

From several commercialized games the technique of changing facial expressions is imported, and a design method of a game character for the player's empathy is expected to be diversified in the future. In this paper, as a design method of a game character for the player's empathy, this makes walking motion for the game character applied with 'human-emotion' factors as statistics variation of a game character in RPG genre. After this paper implements analyzed emotions of human facial expression and walking motions applied with emotion in examples of character animation theory, this paper divides walking motion applied with human-emotion factors into 8 types through relationship to statistics factors in RPG genre. And then these are applied to a knight character, which has the most similarity with human's physical feature of the game characters in RPG genre, and makes walking motion as variable statistics. As a game player controls the game character applied with 'human-emotion' factors, the effect of the player's empathy about the game character becomes higher, and the level of immersion in game play is also expected to increase.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.10
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• pp.1029-1036
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• 2011

An energy-efficient reference walking trajectory generation algorithm is suggested utilizing allowable ZMP (Zero-Moment-Point) region, which maxmizes the energy efficiency for cyclic gaits, based on three-dimensional LIPM (Linear Inverted Pendulum Model) for biped robots. As observed in natural human walking, variable ZMP manipulation is suggested, in which ZMP moves within the allowable region to reduce the joint stress (i.e., rapid acceleration and deceleration of body), and hence to reduce the consumed energy. In addition, opimization of footstep planning is conducted to decide the optimal step-length and body height for a given forward mean velocity to minimize a suitable energy performance - amount of energy required to carry a unit weight a unit distance. In this planning, in order to ensure physically realizable walking trajectory, we also considered geometrical constraints, ZMP stability condition, friction constraint, and yawing moment constraint. Simulations are performed with a 12-DOF 3D biped robot model to verify the effectiveness of the proposed method.

• The Journal of Korean Physical Therapy
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• v.23 no.3
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• pp.13-19
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• 2011

Purpose: In real life there are both straight-paths and curved-paths. To evaluate walking ability of both kinds, a figure-8 walking test (F8WT) was developed. The aim of this study was to validate the measure in hemiplegic patients with walking difficulties and to identify correlations of curved walking ability with straight walking ability, motor function, and walking performance ability. Methods: Twenty subjects participated in this study. Curved walking was measured by a F8WT. Straight walking ability was measured by a 10-meter walking test (10MWT). Dynamic balancea bility was measured by timed up and go (TUG) tests. Walking performance ability was measured using a modified motor assessment scale (MMAS). Motor function was measured by the Fugl-Meyer assessment (FMA) scale. Data were analyzed using Pearson correlation analysis. Linear regression analyses were performed to explore other functional tests in mobility ability by F8WT time, 10MWT (dependent variable). Results: There was a significant positive correlation of F8WT time with 10MWT and TUG. There was a significant negative correlation of F8WT time with MMAS and FMA-coordination. There was a significant positive correlation of 10MWT with TUG. There was a significant negative correlation of 10MWT with MMAS and FMA-coordination. The F8WT time for curved walking ability was attributed to 10MWT for straight walking ability as 94% level of contribution. Conclusion: The results suggest that the F8WT is a good instrument for measuring walking ability because there is a robust correlation of F8WT time with 10MWT, TUG, MMAS, and FMA-coordination in hemiplegic patients who, after stroke, have a mobility deficiency.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.5
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• pp.663-668
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• 2018

A combined CPG (Central Pattern Generator) based foot trajectory and GA (Genetic Algorithm) based joint compensation method is presented for adaptive humanoid walking. In order to increase an adaptability of humanoid walking for rough terrains, the experiment for rolling terrains are introduced. The CPG based foot trajectory method has been successfully applied to basic slops and variable slops, but has a limitation for the rolling terrains. The experiments are conducted in an ODE based Webots simulation environment using humanoid robot Nao to verify a stability of walking for various rolling terrains. The proposed method is compared to the previous CPG foot trajectory technique and shows better performance especially for the cascade rolling terrains.

• Journal of The Korean Society of Integrative Medicine
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• v.4 no.4
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• pp.33-39
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• 2016

Purpose : The aim of this study was to investigate the effects of plastic ankle foot orthosis on adult post-stroke hemiplegic patients walking ability and balance. Method : The searched for the case controlled clinical trials about the effects of plastic ankle foot orthosis(pAFO) for walking ability and balance using quantitative gait analysis in adult post-stroke patients. Ten trials were selected from Riss4U databases published until June 2016 in Korea. The selected trials contained a control group with pre-test and post-test design, measured walking ability and balance as a dependent variable. Result : The selected ten trials involved a total of 180 patients. The walking speed, cadence, the portion of double limb supporting, stride length on affected side were improved by plastic ankle foot orthosis. Conclusion : The plastic ankle foot orthosis has some evidence to improve the walking ability and balance in post-stroke hemiplegic patients.

• Journal of the Korean Society of Safety
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• v.38 no.2
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• pp.112-119
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• 2023

This study analyzes the effects of personal lockers, drinking fountains, and all-in-one shutters (hereinafter referred to as "corridor walking obstacles") on evacuation safety to suggest the necessity of operating a more effective educational facility safety certification system. To achieve this purpose, the five-story high school building with the obstacles installed in the corridor has been chosen, and evacuation tests through the Pathfinder Simulation Program have been carried out. When the evacuation exit is designated in the current state, where the students are placed on the 2nd, 3rd, and 4th floors and the corridor walking obstacles are applied as a variable, the required safe egress time (RSET) is 322 seconds. This can lead to dangerous results in the event of a disaster by exceeding the available safe egress time (ASET) standard of 240 seconds by 82 seconds. When students are placed on the 1st, 2nd, and 3rd floors under the same conditions, the RSET is 214.5 seconds, 25.5 seconds lower than the ASET standard, indicating that it is effective in reducing the impact of walking obstacles on evacuation time. The safety management plan for walking obstacles in the corridors is discussed, considering the special characteristics of the school corridors. The results of this study can be used as the necessary data for optimizing evacuation routes in corridors and creating a safe, educational environment.

• Journal of the Korean Society of School Health
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• v.13 no.2
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• pp.231-240
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• 2000

The purpose of this study is to analyze the relationship between life style and health status of the staffs of an elementary school to understand exercise practices and life styles and to analyze the self-efficacy and the factors that affect it concerning walking exercise. The subjects were m9 staff member of the 10 elementary school in Seoul and materials were collected through an organized examination table from October, 1999 to May 2000. The people health awareness table was used as a variable for life style, the 13 questionnaires made of a 5 points measure was for the self efficacy concerning walking exercise. The data was analyzed through a statistics package made of a Chisquare-test, t-test, ANOVA and a regression analysis. The major results of this study were as follows; 1) 50% of the staffs were practicing regular exercise, 3/4 of them practiced walking, jogging and mountain climbing that don't need equipment and exercise frequency was 1-2 times per week 64%. of the time and exercise span was under 30 minutes in 38%, the highest 2) The average of self-efficacy concerning walking exercise was 3.6 points but the answers "I can walk enough to be in a sweat", "I can walk according to my exercise plan" were relatively low. 3) The explanation degree of the Model was 14% in a regression analysis between self efficacy concerning walking exercise and as a dependent variable for a regular walking exercise plan, regular health examination, routine health status, and breakfast might serve as an explanation degree. According to the results of this study, the suggestions were as follows: 1) The chronic invalid was not enough in the change of life style after chronic disease, most of all, it need the awareness of change, of active health education and of public information for health promotion action practice through the prohibition of smoking, abstinence from drink, exercise and nutritional balance. 2) Concrete practice program enlargement is needed to enhance related walking exercise or of a type lecture meeting for subjects who have a positive attitude about walking exercise plans. 3) A program that can actively recommend a health promotion life style is needed when we make allowance for those who have an ordinarily healthy life style and show a high walking exercise self-efficacy.

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2493-2503
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• 2018

Passive dynamic walking exhibits humanoid and energy efficient gaits. However, optimal design of passive walker at multi-variable level is not well studied yet. This paper presents a Chaotic Particle Swarm Optimization (CPSO) algorithm and applies it to the optimal design of flexible passive walker. Hip torsional stiffness and damping were incorporated into flexible biped walker, to imitate passive elastic mechanisms utilized in human locomotion. Hybrid dynamics were developed to model passive walking, and period-one gait was gained. The parameters global searching scopes were gained after investigating the influences of structural parameters on passive gait. CPSO were utilized to optimize the flexible passive walker. To improve the performance of PSO, multi-scroll Jerk chaotic system was used to generate pseudorandom sequences, and chaotic disturbance would be triggered if the swarm is trapped into local optimum. The effectiveness of CPSO is verified by comparisons with standard PSO and two typical chaotic PSO methods. Numerical simulations show that better fitness value of optimal design could be gained by CPSO presented. The proposed CPSO would be useful to design biped robot prototype.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.5
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• pp.505-511
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• 2011

In this paper, we have developed an automatic velocity control system of a small-sized commercial treadmill (belt length of 1.2 m and width of 0.5 m) which is widely used at home and health centers. The control objective is to automatically adjust the treadmill velocity so that the subject's position is maintained within the track when the subject walks at a variable velocity. The subject's position with respect to a reference point is measured by a low-cost sonar sensor located on the back of the subject. Based on an encoder sensor measurement at the treadmill motor, a state feedback control algorithm with Kalman filter was implemented to determine the velocity of the treadmill. In order to reduce the unnatural inertia force felt by the subject, a predefined acceleration limit was applied, which generated smooth velocity trajectories. The experimental results demonstrate the effectiveness of the proposed method in providing successful velocity changes in response to variable velocity walking without causing significant inertia force to the subject. In the pilot study with three subjects, users could change their walking velocity easily and naturally with small deviations during slow, medium, and fast walking. The proposed automatic velocity control algorithm can potentially be applied to any locomotion interface in an economical way without having to use sophisticated and expensive sensors and larger treadmills.