http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
셀룰로오스섬유강화 복합재 용골 의지발의 걸음걸이역학 비교분석
김사엽(SaYup Kim),노종련,정경렬(Kyung-Ryul Chung),이진복(JinBock Yi),김장환(JangHwan Kim) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12
For the most of lower limb amputees, prosthetic foot is essential part in artificial lower limb. The ideal role of prosthetic foot is to mimic the mechanical features of sound foot. Two important features of prosthetic foot are negative power property in Initial Contact and spring property in Terminal Stance. To achieve these features, various materials and mechanisms have been attempted. In this study, new developed composite material of the cellulose fiber reinforced composite was applied to keel of prosthetic foot. It is expected to be strong and tough enough to be utilized for human weight level applications and exhibit normal gait characteristics. 2 subjects participated in gait capture. They wore 3 kinds of prosthetic foot by turns including theirs, developed cellulose fiber reinforced foot, and typical energy storing foot. In the results, the cellulose-applied foot followed almost mechanical characteristics of typical energy storing sample. Eco-friendly cellulose material showed possibility of application to lower limb prostheses.
KIM, SAYUP,ROH, JONGRYUN,HYEONG, JOONHO,KIM, YOUNGHO World Scientific 2017 JOURNAL OF MECHANICS IN MEDICINE AND BIOLOGY Vol.17 No.8
<P>It is generally believed that running on a curved surface is more unstable than running on a flat surface. In this study, the dynamic stability of locomotion on a nonmotorized curved treadmill (NMCT) with three curvature radii was compared with that on a motorized flat treadmill. Sixteen healthy adult men maintained four different self-paced speeds: slow walking, fast walking, jogging, and running. Significant differences were statistically verified using two-way repeated-measures analysis of variance (ANOVA) according to the curvature radii and speeds, and the interaction effects were confirmed. Furthermore, to understand the significant differences between the speed and curvature radius, <I>post hoc</I> analyses were performed using one-way ANOVA. Except for the step width, the other parameters showed differences and correlation effects between the curvature radius and speed. As the curvature radius decreased, the stability decreased at slow speeds (slow walking) but increased at fast speeds (running). However, as the curvature radius increased, the stability increased at slow speeds (slow walking) but decreased at high speeds (running). The study results will help in suggesting the appropriate curvature radius for different user types such as athletes, the elderly, and people who require rehabilitation and will serve as preliminary data for designing the curvature radii of NMCTs.</P>
클리키 스위치 조작 시 피드백의 명확성을 정량화 하기 위한 햅틱프로파일 분석
형준호(Joonho Hyeong),김사엽(Sayup Kim),노종련(Jongryun Rho),이재환(Jaehwan Lee) 대한인간공학회 2020 大韓人間工學會誌 Vol.39 No.1
Objective: This study aims at investigating the physical factors associated with feedback clarity when operating a clicky switch by analyzing haptic profile. Background: The operating feeling has become more important in PUI. Previously, many studies on the effect of physical parameters of controller on the affective experience have been conducted. The preferred physical parameters such as peak force, stroke and friction has been revealed already in many studies. But there are few quantitative studies on the feeling of feedback clarity which plays an important role in improving the operating feeling. The clarity is a haptic feedback to notify the user if the controller was operated successfully. To investigate the appropriate level of clarity and to improve operating feeling, the quantitative indicators that associated with the perceived clarity needed to be revealed. Method: The reaction force and stroke are measured when a clicky switch was pressed in a constant and voluntary speed. The constant operation was conducted by linear actuator and the voluntary operations were conducted by five human subjects. Each subject was operated 20 times and haptic profile which consists of the force and the stroke was measured. Based on haptic profile, change rate of the force and stroke was further analyzed to extract the acceleration and the rate of force. Results: The reaction force and stroke changed drastically at a time when passing through click section and the acceleration and the rate of force were increased prominently and instantly at that moment. The acceleration can be suggested for physical factor that associated with feedback clarity because the acceleration directly activates a mechanoreceptor called Pacinian corpuscles in human skin. Conclusion: It is understood that the increased peak acceleration associated with the feeling of clarity. The further empirical studies on the preferred acceleration and level of clarity are needed in application area. Application: The results contribute to the design of haptic feedback on the PUI.
A Binary Sleep Classification of BCG Signal using Random Search-Optimized Random Forest
Unang Sunarya,Hyunsoo Yu,Sayup Kim,Cheolsoo Park 대한전자공학회 2021 대한전자공학회 학술대회 Vol.2021 No.6
Sleep has an important role in human daily activities. Lack of sleep might cause fatigue, loss of focus, and furthermore lead to various sleep-related diseases. Research on human sleep has been conducted in many ways starting from high-cost and complex process (polysomnography) to low-cost and simpler process such as actigraphy. Several different methods were used during the experiment such as (EEG), electrocardiography (ECG), and ballistocardiography (BCG) to automate the process for sleep analysis. A machine learning algorithm called random forest has been used to classify awake and sleep states. Additionally, the random forest algorithm was optimized with random search to improve the classification performances. The result showed the accuracy of the optimized random forest was higher (81.35 %) than the result without using the optimization method (79.82 %).
형준호(Joonho Hyeong),김사엽(Sayup Kim),노종련(Jongryun Rho),이재환(Jaehwan Lee) 한국HCI학회 2018 한국HCI학회 학술대회 Vol.2018 No.1
제품의 PUI 에서 촉각적 피드백의 한 종류인 힘과 관련된 경험이 중요해 지고 있다. 사용자가 장치를 조작하는 동안 겪게 되는 힘과 동작의 변화를 객관적으로 해석할 수 있는 수단으로서 햅틱프로파일이 활용되고 있다. 기존의 햅틱프로파일에서 주로 사용되는 파라미터는 힘과 위치가 있지만 이는 사용자 개인별 동작특성을 반영하지 못하는 문제점이 있다. 본 연구에서는 사용자의 실제 경험에 기반을 둔 파라미터로서 힘변화율이라고 하는 새로운 파라미터를 제안함으로써 해석할 수 있는 햅틱프로파일을 제시하고자 한다. 힘, 위치, 그리고 시간이라는 측정가능한 주요 파라미터를 기반으로 힘과 위치의 변화율을 제시하고 햅틱프로파일에 어떻게 사용될 수 있는지를 보였다. 본 연구는 이론적 고찰에 기반을 두었으며 향후 실험을 통해 다양한 조작장치의 햅틱프로파일을 실제적으로 분석해볼 것이다.