• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.35 no.4
• /
• pp.24-32
• /
• 2012

Of many approaches to reduce motion analysis errors, the compensation method of anatomical landmarks estimates the position of anatomical landmarks during motion. The method models the position of anatomical landmarks with joint angle or skin marker displacement using the data of the so-called dynamic calibration in which anatomical landmark positions are calibrated in ad hoc motions. Then the anatomical landmark positions are calibrated in target motions using the model. This study applies the compensation methods with joint angle and skin marker displacement to three lower extremity motions (walking, sit-to-stand/stand-to-sit, and step up/down) in ten healthy males and compares their performance. To compare the performance of the methods, two sets of kinematic variables were calculated using different two marker clusters, and the difference was obtained. Results showed that the compensation method with skin marker displacement had less differences by 30~60% compared to without compensation. And, it had significantly less difference in some kinematic variables (7 of 18) by 25~40% compared to the compensation method with joint angle. This study supports that compensation with skin marker displacement reduced the motion analysis STA errors more reliably than with joint angle in lower extremity motion analysis.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.29 no.4 s.235
• /
• pp.425-434
• /
• 2005

In order to analyze pulsating flows in elastic blood vessels, a method based on the ALE concept and finite volume method was reformed and modulated to include wall motion of elastic vessels and impedance phase angle(phase difference between wall motion and blood flow). Our study indicated wall shear rates(WSR) were significantly influenced by the wall motion and the impedance phase angle. For larger wall motion more than $5{\%},$ the computed WSR started to deviate from the results of the perturbation theory that assumed smaller wall motion. The study showed that oscillatory shear index increased as the impedance phase angle became more negative like $-70{\circ}\;or\;-80{\circ}$ due to reduced mean WSR and increased amplitude of WSR. This result indicated that hypertensive patients are more vulnerable to atherosclerosis than normal persons because of the role of more negative impedance phase angles usually observed in these patients.

• Journal of Biomedical Engineering Research
• /
• v.24 no.6 s.81
• /
• pp.543-548
• /
• 2003

Injuries of wrist in upper extremity is common onset in industrialized world. The development of joint arthroplasty and mechanical joint is area of research for biomechanical engineer and surgeon for a decade. Therefore. the knowledge of characteristic of joint motion is essential to develop the artificial wrist joint. In this study. the joint motions of wrist required for activities of daily living (ADLs). including personal hygiene and care. and general home activity were measured using flexible electrogoniometer. Total of 25 different daily activities were separated into four groups and tested on 15 subjects who did not show any abnormality of their joint functions. The maximum functional range of motion required for ADLs were obtained and standardized for analysis and comparison. Also. a least functional range of motion for ADLs were investigated. Results revealed that any significant differences were not found in least functional range of motion between left and right wrist to perform ADLs. However. a significant difference was found in different ADLs. Therefore. least range of motion obtained in this study can be used as basic data to design artificial joint and set a goal for surgeon to achieve appropriate treatment from patients.

• Physical Therapy Rehabilitation Science
• /
• v.10 no.4
• /
• pp.463-469
• /
• 2021

Objective: If non-surgical treatment fails, arthroscopic rotator cuff repair (ARCR) is recommended, and ARCR considers graft augmentation in consideration of size, direction, and re-tear. It is reported to have potential benefits by improving the healing rate as it can fill the gaps that have been left behind. The purpose of this study is to investigate the effect of structural changes observed after ARCR on muscle action through magnetic resonance imaging and to investigate the effect of appropriate physical therapy required for graft augmentation in the general ARCR rehabilitation protocol. Case presentation: A 47-year-old male hospitalized for postoperative rehabilitation following ARCR participated in a 5-week physical therapy intervention. The postoperative day was 6 months, but due to shooting pain and shoulder dysfunction,and the movement of the shoulder was compensatory motion, not normal motion. Physical agents, manual therapy, and supervised exercise for 110 minutes per session were performed 3 times a week, and pain intensity, range of motion, function, and strength were evaluated. Results: As a result of the study, the patient showed positive improvement in pain intensity, range of motion, function, and strength. In addition, normal scapulohumeral rhythm movement was observed. Conclusions: According to the results of this case, appropriate physical therapy according to the compensatory motion shown in the structural changes after ARCR can positively improve the pain intensity, range of motion, function, and strength of ARCR patients.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2019.05a
• /
• pp.98-100
• /
• 2019

In the past, there were several researchers investigating waves generated by a small boat. Wave generated by a ship can be divided into two distinct systems of waves, such as transverse and diverging waves. It is necessary to understand the behavior of a ship in waves generated by a small boat near port in the view point of ship safety. In this study, the motion of moored floater in waves generated by a small boat near port is investigated. The model test is performed in waves in a square tank in Changwon National University (CWNU). IMU and optical-based system which uses the technique of recording and capturing attitude with respect time are used for measuring 6DOF motion of the moored floater. In addition, tension gauges are used to measure the tension of mooring lines. The effect of waves generated by a small boat on motion of the moored floater near port is investigated through performing the model test in various wave directions of virtually but reasonably assumed wave scenarios.

• The Korean Journal of Emergency Medical Services
• /
• v.24 no.3
• /
• pp.89-106
• /
• 2020

Purpose: This study attempts to improve the status of emergency care for major trauma patients transferred by 119 paramedics by analyzing the status of emergency care and the obstacles to the spinal motion restriction (SMR) for major trauma patients. Methods: A total of 600 rescue logs were collected from major trauma patients transported by 119 paramedics in the C fire department from Jan. 1, 2015, to Dec. 31, 2017. And then, 280 questionnaires were collected from the 119 paramedics in C fire department from May 3 to Jun. 3, 2019. Data were analyzed using SPSS 24.0 version. Results: Among 499 spinal motion restriction adaptive patients, the spinal motion restriction rate was 51.1% (255 individuals). Lack of human resources and quality control problems were among the obstacles to spinal motion restriction. Conclusion: The 119 paramedics should improve their activeness and skills in performing emergency care, and since training and experience are of crucial importance, they should expand various education systematized according to demand.

• Earthquakes and Structures
• /
• v.22 no.1
• /
• pp.53-64
• /
• 2022

This study proposes an intelligent semi-active isolation system combining a variable-stiffness control device and ground motion characteristic prediction. To determine the optimal control parameter in real-time, a genetic algorithm (GA)-fuzzy control law was developed in this study. Data on various types of ground motions were collected, and the ground motion characteristics were quantified to derive a near-fault (NF) characteristic ratio by employing an on-site earthquake early warning system. On the basis of the peak ground acceleration (PGA) and the derived NF ratio, a fuzzy inference system (FIS) was developed. The control parameters were optimized using a GA. To support continuity under near-fault and far-field ground motions, the optimal control parameter was linked with the predicted PGA and NF ratio through the FIS. The GA-fuzzy law was then compared with other control laws to verify its effectiveness. The results revealed that the GA-fuzzy control law could reliably predict different ground motion characteristics for real-time control because of the high sensitivity of its control parameter to the ground motion characteristics. Even under near-fault and far-field ground motions, the GA-fuzzy control law outperformed the FPEEA control law in terms of controlling the isolation layer displacement and the superstructure acceleration.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.47 no.4
• /
• pp.696-710
• /
• 2023

This study investigated the problems of Korean female combat uniforms and collected primary data for developing new combat uniforms with improved functionality. We analyzed fit and motion suitability by administering a questionnaire evaluating the current uniforms to 20 Korean female soldiers. The evaluation of fit suitability found that satisfaction with the combat uniforms was generally high. However, short sleeve length, large wrist circumference, small hip circumference, large ankle circumference, and low crotch height were discomfort factors. In the evaluation of motion suitability, dissatisfaction was found with the sleeve circumference, elbow circumference, armhole circumference, knee crease and crotch height, and back waist height during motion. Therefore, it is necessary to establish a more segmented size system that suits the physique of current female soldiers and to devise appropriate solutions for improving motion suitability. This study is meaningful for its evaluation of the current combat uniform of female soldiers, and it is expected to serve as a reference for the future development of military combat uniforms for this group.

• Journal of muscle and joint health
• /
• v.16 no.2
• /
• pp.125-134
• /
• 2009

Purpose: The purpose of the study was to compare the effects of the Rhy-Kwon exercise with motion beat music program to the Rhy-Kwon with ordinary beat music program on physical fitness and mood in employed women. Method: Total of 29 women who did not have any particular disease were randomly assigned either to a Rhy-Kwon with motion beat music group or to a Rhy-Kwon with ordinary beat music group. Nine subjects in each group completed posttest measures (physical fitness and mood) in 8 weeks. Results: After the 8 weeks of the study period, there were significant improvement in sargent jump and mood especially for the subscale of vigor in the Rhy-Kwon with motion beat music group compared to their counterparts. But no significant differences were found between the groups in other physical fitness measures. Conclusion: The results showed that Rhy-Kwon with motion beat music program would partially improve physical fitness and mood (vigor). Further studies are needed to confirm the effects of Rhy-Kwon with motion beat music program with various populations.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.27 no.1
• /
• pp.1-12
• /
• 2023

Structures of high-rise buildings are less prone to earthquake damage. This is because the response acceleration of high-rise buildings appears to be small by generally occurring short-period ground motions. However, due to the increased construction volume of high-rise buildings and concerns about large earthquakes, long-period ground motions have begun to be recognized as a risk factor for high-rise buildings. Ground motion observed on each floor of the building is affected by the eigenmode of the building because the ground motion input to the building is amplified in the frequency range corresponding to the building's natural frequency. In addition, long-period components of ground motion are more easily transmitted to the floor or attached components of the building than short-period components. As such, high-rise buildings and non-structural components pose concerns about long-period ground motion. However, the criteria (ASCE 7-22) underestimate the acceleration response of buildings and non-structural components caused by long-period ground motion. Therefore, the characteristics of buildings' acceleration response amplification ratio and non-structural components were reviewed in this study through shake table tests considering long-period ground motions.