• Journal of the Korean Society for Precision Engineering
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• v.29 no.3
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• pp.346-353
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• 2012

The purpose of this study is to verify the energy efficiency of the integrated system combining human and a lower extremity exoskeleton robot when it is applied to the proposed gait pattern. Energy efficient gait pattern of the lower limb was proposed through leg function distribution during stance phase and the dynamic-manipulability ellipsoid (DME). To verify the feasibility and effect of the redefined gait trajectory, simulations and experiments were conducted under the conditions of walking on level ground and ascending and descending from a staircase. Experiments to calculate the metabolic cost of the human body with or without the assistance of the exoskeleton were conducted. The energy consumption of the lower extremity exoskeleton was assessed, with the aim of improving the efficiency of the integrated system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4087-4094
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• 2010

The sensor data which is measured by Quadruped robot is utilized to recognize the physical environment or other information and to control the posture and walking of robot system. In order to control the robot precisely, high accuracy of sensor data is required, most of these sensors however, belongs to expensive and low-durable products. Moreover, these are exposed excessive load operation in a field condition if it is applied to field robot system. This issue becomes more serious one when the robot system is manufactured as a mass product. As in this context, this study suggests a virtual sensor technology to alternate or assist the main sensor system. This scheme is realized by using back-propagation algorithm of neural network theory, and the quality of estimated sensor data could be improved through the algorithmic and hardware based treatments. This study performs the various trial to identify the effective parameters which effect to the quality and reliability of estimated sensor data and tries to show the possibility of proposed methodology.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.26 no.1
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• pp.89-99
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• 2017

This paper describes the development of a thigh wearable robot for power assistance during stair climbing. In the wearable robot developed in this study, high-power BLDC motors and high-capacity harmonic reduction gears are used to effectively assist the thigh muscle during stair climbing. In particular, normal ground and stair are distinguished accurately by using wireless smart shoes, and the stair climbing assistance is performed by activating the actuators at an appropriate time. Impedance of the hip joint was effectively reduced by performing friction compensation of the gears, and a wearing adjustment mechanism was designed to fit the robot to the thigh by conveniently modifying the width and tilting angle of the robot using set collars. Consequently, the performance of the developed thigh wearable robot was verified through stair climbing experiments with EMG measurement.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.4
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• pp.819-825
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• 2003

The purpose of this study is to develop the speaker recognition system which can select one of operating modes in FES for general paralysis patients. As spiral injury by traffic accident, industrial disaster, or stroke has been increased, the development of FES(Functional Electrical Stimulator) system is urgent to prevent paralysis and atrophy, and to assist the patients walking. For these patients we developed FES system(1). To operate this system one of several operating modes must be selected. As this can not be done by general paralysis patients, an attempt has been tried in this study to select the mode by speaker recognition system. RSC-300 of sensory co. has been chosen as a speaker recognition chip, and PIC16F84 is adapted to interface RSC-300 and FES system.

• Smart Structures and Systems
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• v.18 no.3
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• pp.625-642
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• 2016

The rapid technology developments in smartphones have created a significant opportunity for their use in structural live load measurements. This paper presents extensive experiments conducted in two stages to investigate this opportunity. Shaking table tests were carried out in the first stage using selected popular smartphones to measure the sinusoidal waves of various frequencies, the sinusoidal sweeping, and earthquake waves. Comparison between smartphone measurements and real inputs showed that the smartphones used in this study gave reliable measurements for harmonic waves in both time and frequency domains. For complex waves, smartphone measurements should be used with caution. In the second stage, three-dimensional motion capture technology was employed to explore the capacity of smartphones for measuring the movement of individuals in walking, bouncing and jumping activities. In these tests, reflective markers were attached to the test subject. The markers' trajectories were recorded by the motion capture system and were taken as references. The smartphone measurements agreed well with the references when the phone was properly fixed. Encouraged by these experimental validation results, smartphones were attached to moving participants of this study. The phones measured the acceleration near the center-of-mass of his or her body. The human-induced loads were then reconstructed by the acceleration measurements in conjunction with a biomechanical model. Satisfactory agreement between the reconstructed forces and that measured by a force plate was observed in several instances, clearly demonstrating the capability of smartphones to accurately assist in obtaining human-induced load measurements.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.3
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• pp.181-189
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• 2015

Powered prosthesis is used to assist walking of people with an amputated lower limb and/or weak leg strength. The accurate gait phase classification is indispensable in smooth movement control of the powered prosthesis. In previous gait phase classification using physical sensors, there is limitation that powered prosthesis should be simulated as same as the speed of training process. Therefore, we propose EMG signal based gait phase recognition method to classify stairs ascending and stairs descending into four steps without using physical sensors, respectively. RMS, VAR, MAV, SSC, ZC, WAMP features are extracted from EMG signal data and LDA(Linear Discriminant Analysis) classifier is used. In the training process, the AHRS sensor produces various ranges of walking steps according to the change of knee angles. The experimental results show that the average accuracies of the proposed method are about 85.6% in stairs ascending and 69.5% in stairs descending whereas those of preliminary studies are about 58.5% in stairs ascending and 35.3% in stairs descending. In addition, we can analyze the average recognition ratio of each gait step with respect to the individual muscle.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.4
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• pp.47-65
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• 2002

The purpose of this paper is to study and propose playground facilities for physically challenged children to cultivate adaptability in society and advances the opportunity of participate in physical exercise. This study carried out site investigations by visiting and inspecting various facilities: a recreational walking path for physically challenged people, a care facility for physically challenged children, a special school for physically challenged children, and "Madel Park", a private-use playground for physically challenged children. The result of the site investigation found that, overall, play facilities are difficult to use for physically challenged children. In addition, because park space is often small and narrow, children who are restricted to wheelchairs find it impossible to access such facilities. By carefully inspecting each of the facilities, the author found suitable elements to apply for outside play space. These elements include the introduction of an essential slope way to allow for safe movement, the provision of special seats which support the body to outside play equipment and the adaptation of treatment room instruments that assist balance to outdoor playground facilities. On the basis of the site investigation the interview and the indoor education program for physically challenged children the author completed an outside play program. Each item in this program was classified as belonging to either a "sense play" program or and "exercise play" program. Finally, the author designed suitable play equipment for physically challenged children corresponding to each item in the exercise programs in order to research the appropriateness of the equipment to its intended use. This research is the first step. From this point the author expects that specific applications will be developed through a practical space plan and sufficient clinical experiments involving use of the new equipment.

• Journal of Chest Surgery
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• v.10 no.1
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• pp.133-139
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• 1977

Two cases of congenital aneurysm of sinus of Valsalva, ruptured into the right ventricle, and associated with ventricular septal defects, were undergone intracardiac repair with the aid of extracorporeal circulation using Bentley bubble oxygenator and moderate hypothermia. Case 1. A 20 year old male, with the chief complaints of palpitation and dyspnea, was admitted to Kyungpook National University Hospital on Dec. 16, 1976. Continuous machinery murmur was heard best at left 3rd. intercostal space along the sternal border. Retrograde aortography disclosed aneurysm of the right coronary cusp, which ruptured into the right ventricle. Utilizing cardiac bypass and moderate hypothermia, the right ventricle was opened and aneurysm was closed by direct sutures. Associated ventricuar septal defect was directly ,closed and suture line was reinforced by Dacron patch. Total bypass time was 112 minutes and total aortic cross clamping time was 37 minutes. Assist ventilation was carried out for 28 hours postoperatively. His postoperative course was smooth except removal o1 substernal hematoma and he was .discharged on 24th postoperative day. Case 2. A 28 year old man was admitted to our Hospital on June 9, 1976. two weeks prior to this admission, suddenly he had collapsed while he was walking on the street. Following `this episode, palpitation, dyspnea on exertion and frequent respiratory infection developed. Grade IV systolic murmur was heard best at 3rd intercostal space along the sternal border. Retrograde aortography confirmed the diagnosis of rupture of aneurysm of the sinus Valsalva ruptured into the right ventricle. Under the cardiopulmonary bypass the right ventricle was opened and ruptured aneurysm and infracristal ventricular septal defect were directly closed and reinforced with Dacron patch. Postoperative course was uneventful and he was discharged on 14th postoperative day. The pathogenesis of aneurysm of the sinus Valsalva and mode of diagnosis were discussed. Principle of surgical repair was presented.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.3
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• pp.177-185
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• 2014

In this study, the exoskeleton orthosis for the assistance of dorsiflexion torque in ankle joint to prevent foot-drop was developed. It was consist of three part; 1) the power part using artificial pneumatic actuator, 2) wearing part of ankle and knee joints to fix the orthosis, and 3) control part to detect the gait phase using physiological signal. The dorsiflexion torque was generated by the artificial pneumatic actuator connected with wearing part between ankle and knee joint. The accurate timing to assist dorsiflexion torque is made up of physiological signal in foot sole part that detect the gait phase, that is, stance and swing phase in each foot. We conduct the experiment to investigate the effect of exoskeleton orthosis to the 7 elderly people and 10 healthy people. The result showed that the muscular activities in tibialis anterior muscle were reduced because of the assistance of dorsiflexion torque in ankle joint using the exoskeleton orthosis.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.4
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• pp.167-178
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• 2023

Our society is rapidly changing, and there is a growing demand for various convenience services in our daily lives. Among these services, railway and subway stations require tailored wayfinding services to accommodate individuals with disabilities. Currently, signage and information desks are the primary means of navigation. However, individuals with disabilities often rely on assistance from others due to physical discomfort or cognitive impairments. In this paper, we propose a customized wayfinding system within railway stations to assist individuals with disabilities. This system aims to ensure safe and convenient mobility in complex indoor environments, including transfer facilities.