• Journal of Institute of Control, Robotics and Systems
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• v.9 no.1
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• pp.73-81
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• 2003

An autonomous stair robot recognizing the stair, and climbing up and down the stair by utilizing a robot vision, photo sensors, and appropriate climbing algorithm is introduced. Four arms associated with four wheels make the robot climb up and down more safely and faster than a simple track typed robot. The robot can adjust wheel base according to the stair width, hence it can adopt to a variable width stair with different algorithms in climbing up and down. The command and image data acquired from the robot are transferred to the main computer through RF wireless modules, and the data are delivered to a remote computer via a network communication through a proper data compression, thus, the real time image monitoring is implemented effectively.

• Physical Therapy Korea
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• v.15 no.2
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• pp.54-63
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• 2008

The purpose of this study was to examine the effect of the hip internal rotation on knee extensor and hip abductor electromyographic (EMG) activity during stair up and stair down mobility. Eighteen healthy subjects were recruited. All subjects performed stair up and down movements on a step of 30cm height while maintaining the hip in neutral (condition 1) and hip in internal rotation (condition 2). Surface EMG activity was recorded from five muscles (gluteus maximus, vastus lateralis (VL), vastus medialis oblique (VMO), posterior gluteus medius (Gmed), and tensor fascia latae (TFU)) and hip internal rotation angle was measured using a three dimensional motion analysis system The time period for stair up and down was normalized using the MatLab 6.5 program, and EMG activity was normalized to the value of maximal voluntary isometric contraction (%MVIC). The EMG activities according to the hip rotation (neutral or internal rotation) during the entire time period of stair up and down in each phase were compared using a paired t-test. During the entire period of stair up, the EMG activities of VL and TFL in condition 2 were significantly greater than in condition 1 (p<.05). During the entire period of stair down, the EMG activities of VL and TFL in condition 2 were significantly greater than in condition 1 (p<.05). However, the EMG activities of the other muscles were not significantly different between the conditions (p>.05). These results suggest that the stair up and down maintaining hip internal rotation was could be a contributing factor on patellar lateral tracking.

• PNF and Movement
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• v.15 no.1
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• pp.105-113
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• 2017

Purpose: The purpose of this case study was to examine the effects of an intervention based on the concept of proprioceptive neuromuscular facilitation (PNF) on the weight-supporting ability, fear of falling, and stair-walking ability of stroke patients. Methods: One pretest, three intervention sessions, and one posttest were conducted. In the tests, weight-supporting ability, manual muscle strength, the fear of falling, and the time to go up and down a 'ㄱ'-shaped stair-walking machine were measured and compared. The intervention was implemented for 30 minutes per day for three days in combination with general rehabilitation. The intervention was planned and implemented based on the concept of PNF, and the goal was for the subjects, after their consent, to walk backward down the stairs. Results: After the intervention, functional improvement was seen in weight-supporting ability and the fear of falling felt when walking down the stairs. Whereas the subjects could not perform the task of walking down the stairs on the 'ㄱ'-shaped stair-walking machine in the pretest, they could perform the task in the posttest, and their stair-climbing speed was greater than before the intervention. Conclusion: This study verified that a PNF-based intervention can improve stroke patients' weight-supporting ability and stair-walking ability. Therefore, this intervention can be clinically applied to stroke patients.

• Fire Science and Engineering
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• v.22 no.1
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• pp.29-36
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• 2008

This study is intended to examine the effect of the evacuation guidance that used phosphorescent material for stairs in the event of smoke and failure of both the power to the lighting and illuminated sign. To achieve the purpose, the test stairs was established and 35 students(1st 20, 2nd 15) were examined the visibility, the convenience and the comfort of going up and down of stairs. The results of this study are as follows; The evacuation from stairs showed that the stair nosing and landing used phosphorescent material for was very effective in dark conditions(0 lux) because of the high visibility of stair nosing and the convenience and the comfort of going up and down of stairs. The phosphorescent material located on the stair nosing and stair landing will aid in evacuation from stairs in the event of failure of both the power to the lightings and illuminated sign.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.10
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• pp.1269-1279
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• 1995

A mobile robot in a nuclear power plant is usually needed to equip the ability of going up and down stairs for a some kind of inspection. For this purpose, it is necessary for the mobile robot to figure out the size of stairs laid on a navigation path to gurantee robot's moving freely. In this paper, to measure the size of stairs existing in front of a mobile robot we designed the stair size recognition unit which can measure the stair's height and width using an ultrasonic sensor and/or a CCD camera. Also to obtain higher reliability of ultrasonic sensing data we proposed the horizontal sensing method. On the assupmtions that the mobile robot generates a trajectory while ascending stairs, we simulated it on a IBM compatible computer. The result showed that the suggested method satisfied our purpose. In a stair size estimation, the detected stair's height error was about .+-.3mm, and width was about .+-.5mm.

• Physical Therapy Korea
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• v.13 no.3
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• pp.10-17
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• 2006

The purpose of this study was to determine the consequence of resistance strengthening exercise on the hip flexor and extensor performed to improve functional mobility in stroke patients more than six months post stroke. Seventeen patients were randomized into two groups. Both groups received conventional physical therapy for six weeks. In addition, the experimental group performed eccentric resistance strengthening exercise in the hip flexor and extensor using an isokinetic dynamometer. The hip flexor and extensor strength, stair up and down mobility, timed get up and go (TUG), 10 m gait velocity, and functional reach were repeatedly measured at baseline, three weeks, and six weeks after treatment. The results were as follows: 1. The experimental group improved more remarkably in the hip flexor and extensor strength, stair up and down mobility, and the 10 m gait velocity after three weeks and six weeks of treatment (p<.05), 2. The control group improved significantly in the hip flexor and extensor strength, and 10 m gait velocity after three weeks of treatment (p<.05), 3. At each three and six week point, the experimental group made greater gains in hip flexor and extensor strength, stair up and down mobility, and 10 m gait velocity than the control group (p<.05). In conclusion, it is desirable to perform resistance strengthening exercises combined with conventional physical therapy to improve functional mobility in chronic stroke patients.

• Physical Therapy Rehabilitation Science
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• v.7 no.3
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• pp.134-138
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• 2018

Objective: The aim of this research was to investigate the effects of functional electrical stimulation (FES) applied to the gluteus medius (Gm) and tibialis anterior (TA) during stair climbing in persons with stroke compared to FES applied to the TA only during stair climbing, and during stair climbing without FES in persons with stroke. Design: Cross-sectional study. Methods: Twenty subjects with stroke participated in this study. Subjects were included if: 1) they were diagnosed as stroke at least 6 months before; 2) had Mini Mental State Examination- Korean score of 24 or higher; 3) were able to climb a flight of 10 stairs independently (with or without walking aid). The patients walked 10 stairs 3 times with FES applied to the Gm and TA, only TA, or no FES. There was a 1-minute rest period between each bout. The assessments were made using the Timed Up & Down Test and the Wii Balance Board. Results: Stair climbing with FES applied to the Gm and TA was significantly faster than stair climbing with FES applied to the TA only and without FES (p<0.05). Stair climbing with FES applied to the Gm and TA exhibited significantly greater sway velocity than stair climbing without FES (p<0.05). However, maximal sway distances were not significantly different between groups. Conclusions: Stair climbing with FES applied to the Gm and TA can be an important component of a rehabilitation program for improving stair climbing ability in persons with stroke.

• Physical Therapy Korea
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• v.16 no.3
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• pp.24-31
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• 2009

This study aimed to investigate the effect of differing heel heights on the electromyographic (EMG) activity in vastus medialis (VM) and vastus lateralis (VL) during stair ascending and descending activities. A total of 26 healthy women volunteered to perform stair-ascending and stair-descending tasks with 3 heel heights: barefoot, 3 cm, and 7 cm. The EMG activities of the VM and VL were recorded during the tasks. During the stair ascending and descending tasks, the EMG activities of both VM and VL significantly changed with differing the heel heights (p<.05). Moreover, the EMG activities of VM and VL during the stair ascending task were significantly higher than the corresponding values during the stair-descending task (p<.05). However, there were no significant differences between the VM:VL EMG ratios for the 3 heel heights (p>.05). The VM:VL EMG ratios between the 2 tasks differed significantly in the 7 cm high heel condition (p<.05). Despite an increase in the EMG activities in both VM and VL during stair ascending and descending tasks, there was no change in the relative EMG intensities of VM and VL, which was measured by calculating the VM:VL ratio this result indicates that no VM:VL imbalances were elicited. The relative EMG intensities of VM and VL during stair descent were lower than the corresponding values during the ascent, suggesting that VM and VL may show an imbalance in the eccentric activation during the weight-acceptance phase. This study provides useful information that will facilitate future research on how heel height affects muscle activity around the knee joint.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.104.3-104
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• 2002

A quadruped stair robot introduced here plays a role in monitoring and moving some place where an operator can not reach or when he may not keep watching. It has several features that travels and poses variable position by four caterpillars and quadruped typed arms, transmits an image and command data via RF wireless and network communication. The robot can balance itself when it moves up and down on a slope by using the quadruped mechanism. The robot vision scans ahead before it moves, and the captured image is transferred to a main computer via a RF image module. The main computer analyzes the obstacle, and when it is found the obstacle, the robot avoids from the obstacle and keep moving f...

• Journal of the Korean Society for Precision Engineering
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• v.23 no.4 s.181
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• pp.75-82
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• 2006

In this paper, we propose an optimal trajectory for biped robots to move up-and-down stairs using a genetic algorithm and a computed-torque control for biped robots to be dynamically stable. First, a Real-Coded Genetic Algorithm (RCGA) which of operators are composed of reproduction, crossover and mutation is used to minimize the total energy. Constraints are divided into equalities and inequalities: Equality constraints consist of a position condition at the start and end of a step period and repeatability conditions related to each joint angle and angular velocity. Inequality constraints include collision avoidance conditions of a swing leg at the face and edge of a stair, knee joint conditions with respect to the avoidance of the kinematic singularity, and the zero moment point condition with respect to the stability into the going direction. In order to approximate a gait, each joint angle trajectory is defined as a 4-th order polynomial of which coefficients are chromosomes. The effectiveness of the proposed optimal trajectory is shown in computer simulations with a 6-dof biped robot that consists of seven links in the sagittal plane. The trajectory is more efficient than that generated by the modified GCIPM. And various trajectories generated by the proposed GA method are analyzed in a viewpoint of the consumption energy: walking on even ground, ascending stairs, and descending stairs.