• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2492-2497
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• 2003

This paper presents optimal walking trajectory generation for a quadruped robot with genetic-fuzzy algorithm. In order to move a quadruped robot smoothly, both generations of optimal leg trajectory and free walking are required. Generally, making free walking is difficult to realize for a quadruped robot, because the patterned trajectory may interfere in the free walking. In this paper, we suggest the generation method for the leg trajectory satisfied with free walking pattern so as to avoid obstacle and walk smoothly. We generate via points of leg with respect to body motion, and then we use the genetic-fuzzy algorithm to search for the optimal via velocity and acceleration information of legs. All these methods are verified with PC simulation program, and implemented to SERO-V robot.

• Journal of Korean Physical Therapy Science
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• v.15 no.3
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• pp.55-63
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• 2008

Background : The Purposes of this study were to understand difference between free walking and obstacle over walking through the naked eye and motion analysis device, and to review merits of obstacle walking training as item of functional assessment in clinical situations. Methods : All participants were male and performed 3 types of walking methods: free walking, obstacle over walking with low block(height=10cm, width=8cm), and obstacle over walking with high block(height=20cm, width=8cm). All walking were performed 3 trials respectively. Results : In the naked eye, initial contact with toes occurred more than heel strike in obstacle over walking, and the flexion angle of hip and knee were increased in obstacle over walking. On interpretations though motion analysis device, cadence, gait speed and weight accept were significant statistically(p<.05). Cadence and gait speed were decreased, and weight accept duration was increased in obstacle over walking. Rotation among three pelvic motions was significant statistically(p<.05), flexion among three hip motions was significant statistically(p<.05) and flexion among three ankle motions was significant statistically(p<.05). Rotation and flexion among three ankle motions was significant statistically(p<.05). Conclusion : Both the naked eye and interpretations of the device presented many difference between free walking and obstacle over walking. In overcrossing obstacles, many participants appeared walking strategy by perform initial contact with toes. Knee flexion was most significant statistically(p<.05) in obstacle over walking with 20cm block.

• The Korean Journal of Physiology
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• v.5 no.2
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• pp.29-40
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• 1971

Oxygen consumption, pulmonary ventilation, heart rate, and breathing frequency were measured on 8 men walking on a treadmill carrying load of 9 kg on hand, back, or head. Besides measurements were made on subjects carrying loads of 2.6 kg each on both feet. The speed of level walking was 4, 5, and 5.5km/hr and a fixed speed off km/hr with grades of 0, 3, 6, and 9%. Comparisons were made between free walking without load and walking with various types of loads. The following results were obtained. 1. In level or uphill walking the changes in oxygen consumption, pulmonary ventilation, breathing frequency and heart rate were smallest in back load walking, and largest in hand load walking. The method of back load was most efficient and hand load was the least efficient. The energy cost in head load walking was smaller than that of in hand load walking. It was assumed that foot load costed more energy than hand load. 2. In level walking the measured parameters increased abruptly at the speed of 5.5 km/hr. Oxygen consumption in a free walking at 4 km/hr was 11.4ml/kg b.wt., and 13.1 ml/kg b.wt. 5.5 km/hr, and in a hand load walking at 4 km/hr was 13.9, and 18.8 ml/kg b. wt. at 5.5 km/hr. 3. In uphill walking oxygen consumption and other parameters increased abruptly at the grade of 6%. Oxygen consumption at 4 km/hr and 0% grade was 11.4 ml/kg b. wt., 13.6 at 6% grade, and 16.21/kg b. wt. at 9% grade in a free walking. In back load walking oxygen consumption at 4km/hr and 0% grade was 12.3 ml/kg b.wt.,14.9 at 6% grade, and 18.7 ml/kg b.wt. In hand load walking the oxygen consumption was the greatest, namely, 13.9 at 0% grade, 17.9 at 6%, and 20.0 ml/kg b. wt. at 9% grade. 4. Both in level and uphill walking the changes in pulmonary ventilation and heart rate paralleled with oxygen consumption. 5. The changes in heart rate and breathing frequency in hand load were characteristic. Both in level and uphill walk breathing frequency increased to 30 per minute when a load was held on hand and showed a small increase as the exercise became severe. In the other method of load carrying the Peak value of breathing frequency was less than 30 Per minute. Heart rate showed 106 beats/minute even at a speed of 4 km/hr when a load was held on hand, whereas, heart rate was between, 53 and 100 beats/minute in the other types of load carriage. 6. Number of strides per minute in level walking increased as the speed increased. At the speed floater than 5 km/hr number of strides per minute of load carrying walk was greater than that of free walking. In uphill walk number of strides per minute decreased as the grade increased. Number of strides in hand load walk was greatest and back load walk showed the same number of strides as the free walk.

• Physical Therapy Korea
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• v.14 no.4
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• pp.84-90
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• 2007

The purpose of this study was to assess the test-retest reliability of heart rate (HR) and velocity measurements during peak effort and free treadmill walking tests in older patients with gait-impaired chronic hemiparetic stroke and control group. Twenty-two adults (13 men, 9 women; mean age, $73.7{\pm}5.2$ yrs) with chronic hemiparetic stroke are the experimental group. Nineteen elderly people (5 men, 14 women; mean age, $72.3{\pm}3.5$ yrs) were recruited as control group. Patients had mild to moderate chronic hemiparetic gait deficits, making handrail support necessary during treadmill walking. Free and peak effort treadmill walking tests were measured and then repeated at least two days later. Reliability was calculated from HR and walking velocity during free and peak effort treadmill walking test. Among the people who had strokes, HR [ICC(2,1)=.85, r=.86] and velocity [ICC(2,1)=.93, r=.93] were good parameters during free testing. Maximal testing generated good results for HR [ICC(2,1)=.81, r=.82] and velocity [ICC(2,1)=.96, r=.96] with the chronic hemiparetic stroke. In elderly people, HR [ICC(2,1)=.59, r=.62] and velocity [ICC(2,1)=.77, r=.76] were moderately reliable during free testing. Maximal testing produced moderate parameters for HR [ICC(2,1)=.74, r=.74] and velocity [ICC(2,1)=.66, r=.66] in the elderly. This study provides that free and maximal treadmill testing produce highly reliable HR and velocity measurements in adults with chronic hemiplegia using minimal handrail support.

• Journal of the Korean Institute of Landscape Architecture
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• v.23 no.2
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• pp.157-166
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• 1995

To investigate walkability of ramps, walking patterns of 18 healthy adults,12 aged 20 to 26 and 6 aged 68 to 76,were studied at free,rhythm constrained walking up or down ramp using goniometer and footswitch Ramp inclinations were set 4,8,12,16,20 degrees. The results were as follows. 1)The step length of subjects were decreased significantly in12$^{\circ}C$′or 16′free downramp walking. With regard to step length, some subject groups walked abnormally in 16" or 20" ramp walking 2) The step width of subjects were increased significantly in 12" or 16" ramp walking. 3) The cadence duration of some subject groups were increased in 12" upramp walking. 4) The double stance duration and double stance ratio of some subject groups were increased significantly in 8",12", or 16"upramp walking. 5) The maximum knee flexion angle of stance phase were increased in 12" ramp walking. 6)Most temporal parameters and spatial parameters of gait were increased or decreassd greatly between 4" ramp and 8" ramp or between 8′ramp and 12′ramp. But statistics significancy were not recognized 7) The results suggest that ramp inclination less than 8′(14%) -12′(21%) is desirable for the normal gait the ramp inclination must not exceed 16" -20" in unavoidable circumstances.

• Journal of The Korea Institute of Healthcare Architecture
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• v.15 no.1
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• pp.33-40
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• 2009

This study aims to plan connecting living facilities considering on the Barrier Free Walking of the disabled and the elderly in the residential area. We had found several physical problems on the pedestrian's way that becomes the major factor of disturbing the barrier free movement for using living facilities in the local area by investigations and enquetes. We had suggested the arrangement method for these physical problems on the pedestrian's way and building the ideal area for living facilities by the disposition stages with the result of investigations and enquetes. After these process, we had planned connecting living facilities considering on the Barrier Free Walking of the disabled and the elderly in the residential area.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.311-314
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• 1995

Biped locomotion can be simply modeled as a linear inverted pendulum mode. This model considers only the CG (center of gravity) of the entire system. But in real biped robot systems, the free-leg motion dynamics is not negligible. So if its dynamics is not considered in designing the reference CG motion, it is badly influence to the ZMP(zero moment point) position of the biped robot walking in the sagittal plane. Therefore, we modeled the biped locomotion similar to the linear inverted pendulum mode but considered the predetermined free-leg dynamics. To verify that the proposed biped locomotion is more stable than the linear inverted pendulum mode, we constructed a biped robot simulator and designed a serco controller to track both the reference motion of the free leg and the reference motion of CG of the biped robot using the computed torque control low. And through simulations, we verified that the proposed walking is better in stability than the one based on the linear inverted pendulum mode.

• Korean Journal of Applied Biomechanics
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• v.20 no.4
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• pp.479-486
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• 2010

The purpose of this study was to determine the effects of high-heeled shoe on the quiet standing and gait balance. Twenty women (mean height: $161.6{\pm}3.3\;cm$, mean body mass: $53.8{\pm}6.3\;kg$, mean age: $23.8{\pm}2.7$ yrs..) who were without history or complain of lower limb pain took part in this study. They were asked to stand quietly on a force platform for 30 sec and walk on it at their preferred walking speed (mean speed $3.14{\pm}0.5\;km/hr$.) with wearing three different high-heeled shoe, 3, 7, 9 cm high for collecting data. Data were randomly recorded to collect two trials for quiet standing and five trials for walking The parameters to have been analyzed for comparison between three conditions of the height of high-heeled shoe were COP(Center of Pressure) range, COP velocity, sway area, and free moment on the static balance and COP range, COP velocity, and free moment on the dynamic balance. In this study, high-heel height affected on the COP range and velocity in the ante-posterior direction during walking, dynamic balance, but didn't affect on the quiet standing, static balance.

• The Korean Journal of Zoology
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• v.26 no.2
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• pp.95-106
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• 1983

Selections for rapid and slow walking behavior were carried out with the populations, drived from Oregon-R and lethal free strain of Drosophila melanogaster. The behavior was measured by means of connected test-tube apparatus. The populations responded effectively to the artificial selection, and it reached the selection plateau after 7 generations. The realized heritability for the first 10 generations was estimated to be about $9\\sim14%$ for the rapid walking behavior, and those for slow walking behavior was about $11\\sim16%$. The results of hybridization analysis between selected populations at generations 8 and 10 indicated that some polygenes showing a slow walking behavior were partially dominant over polygenes controlled rapid trait. The populations selected for rapid and slow walking behavior were relaxed after 10 generations of selection. The response to natural selection of rapid population was completely returned to their neutral states after only 5 generations. Such phenomena would be explained by the genetic homeostasis resulted from an action of natural selection. However, the slow population did not make any difference from walking scores of their original artificial selection. It seems reasonable to assume that the slow walking behavior was possibly controlled by a major gene.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.12
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• pp.38-44
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• 2002

A walking training robot is proposed to provide stable and comfortable walking supports by reducing body weight load partially and a force control of an arm of walking training robot using sliding mode controller is also proposed. The current gait training apparatus in hospital are ineffective for the difficulty in keeping constant unloading level and for the constraint of patients' free walking. The proposed walking training robot effectively unloads body weight during walking. The walking training robot consists of an unloading manipulator and a mobile platform. The manipulator driven by an electro-mechanical linear mechanism unloads body weight in various levels. The mobile platform is wheel type, which allows patients to walt freely. The developed unloading system has advantages such as low noise level, lightweight, low manufacturing cost and low power consumption. A system model fur the manipulator is established using Lagrange's equation. To unload the weight of the patients, sliding mode control with p-control is adopted. Both control responses with a weight and human walking control responses are analyzed through experimental implementation to demonstrate performance characteristics of the proposed force controller.