• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.4
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• pp.448-453
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• 2012

There are many researches to develop robots that improve its mobility to adapt in various uneven environments. In the paper, a hybrid wheeled and legged mobile robot is designed and a obstacle avoidance algorithm is proposed based on low power walking using LRF(Laser Range Finder). In order to stabilize the robot's motion and reduce energy consumption, we implement a low-power walking algorithm through comparison of the current value of each motors and correction of posture balance. A low-power obstacle avoidance algorithm is proposed by using LRF sensor. We improve walking stability by distributing power consumption and reduce energy consumption by selecting a shortest navigation path of the robot. The proposed methods are verified through walking and navigation experiments with the developed hybrid robot.

• Journal of the Korean Society of School Health
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• v.19 no.2
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• pp.59-74
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• 2006

Purpose : The principal objective of this study was to develop adequate health promotion programs satisfying the needs of high school students by exploring a variety of factors that affected their participation in these programs. This research was also designed to serve as preliminary data for the development of health promotion programs that will encourage active student participation. Methods : The study used a descriptive correlational design. The study participants were 658 coeducational high school students in Seoul, consisting of 317 9th graders and 341 10th graders. For this study, 599 structured questionnaires were selected. The survey was conducted for the period from December 12, 2005 to December 23, 2005. Results : Overall, students surveyed in this research showed relatively active participation in health-promoting behaviors. Among 5 dimensions, interpersonal support received the highest score while health responsibility ranked the lowest. Another finding was that posture correction program enjoyed the strongest student participation (75.5%) followed by stress management program(70.1%) and weight control program (56.6%). On the other hand, the participation rates for no-drinking(12.9%), smoking cessation program(17.0%), and influenza prevention program(22.9%) were at the low end. Multiple logistic regression results indicate that the higher interpersonal support score of health promoting behaviors gets, the higher student participation becomes. Conclusion : The study demonstrated that student participation was determined by the nature of health-promoting programs, demographic characteristics and health related physical fitness. It also showed that the sub-scales of the programs played a bigger role in student participation. Keeping this in mind, a wealth of health-enhancing programs of distinguishing qualities need to be tailored to meet various needs of students. In addition, serious efforts should be made to motivate them to seek relevant health promotion programs.

• Korean Journal of Applied Biomechanics
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• v.26 no.4
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• pp.433-441
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• 2016

Objective: The purpose of this study was to understand the injury mechanism and to provide quantitative data to use in prevention or posture correction training by conducting kinematic and kinetic analyses of risk factors of lower extremity joint injury depending on the change of direction at different angles after a landing motion. Method: This study included 11 men in their twenties (age: $24.6{\pm}1.7years$, height: $176.6{\pm}4.4cm$, weight: $71.3{\pm}8.0kg$) who were right-leg dominant. By using seven infrared cameras (Oqus 300, Qualisys, Sweden), one force platform (AMTI, USA), and an accelerometer (Noraxon, USA), single-leg drop landing was performed at a height of 30 cm. The joint range of motion (ROM) of the lower extremity, peak joint moment, peak joint power, peak vertical ground reaction force (GRF), and peak vertical acceleration were measured. For statistical analysis, one-way repeated-measures analysis of variance was conducted at a significance level of ${\alpha}$ <.05. Results: Ankle and knee joint ROM in the sagittal plane significantly differed, respectively (F = 3.145, p = .024; F = 14.183, p = .000), depending on the change of direction. However, no significant differences were observed in the ROM of ankle and knee joint in the transverse plane. Significant differences in peak joint moment were also observed but no statistically significant differences were found in negative joint power between the conditions. Peak vertical GRF was high in landing (LAD) and after landing, left $45^{\circ}$ cutting (LLC), with a significant difference (F = 9.363, p = .000). The peak vertical acceleration was relatively high in LAD and LLC compared with other conditions, but the difference was not significant. Conclusion: We conclude that moving in the left direction may expose athletes to greater injury risk in terms of joint kinetics than moving in the right direction. However, further investigation of joint injury mechanisms in sports would be required to confirm these findings.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.5
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• pp.667-676
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• 2021

Recently, adolescents in Korea are exposed to the risk of postural imbalance due to overuse of smartphones and lack of physical activity due to the amount of learning. In addition, the need for effective non-face-to-face exercise services is increasing due to Corona 19. With this in mind, this study proposes an exercise service using an EMG sensor to overcome the limitations of non-face-to-face services while providing the effect of improving round shoulders for adolescents. An exercise program that can improve round shoulders was constructed, and an application in conjunction with an EMG sensor was implemented to exercise effectively. The exercise program was configured to alternately exercise the target muscle area for 4 weeks, and the function to provide feedback was added by measuring the EMG values that change accordingly. Through this study, we intend to provide the basis for exercise-based posture correction digital service, and improve the unbalanced body through this, thereby promoting the possibility of health promotion.

• Journal of the Institute of Convergence Signal Processing
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• v.21 no.4
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• pp.195-201
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• 2020

This study studied scoliosis, one of the most common modern diseases caused by lifestyle patterns of office workers sitting in front of computers all day and modern people who use smart phones frequently. Scoliosis is a typical complication that takes more than 80% of the nation's total population at least once. X-ray are used to test for these complications. X-ray, a non-destructive testing method that allows scoliosis to be easily performed and filmed in various areas such as the chest, abdomen and bone without contrast agents or other instruments. We uses NI DAQ to miniaturize digital X-ray imaging devices and image intensifier in self-shielding housing with Vision Assistant for drawing lines to the top and the bottom of the spine to acquire angles, i.e. curvature in real-time. In this way, the research was conducted to see scoliosis patients and their condition easily and to help rapid treatment for solving the problem of posture correction in modern people.

• Journal of Biomedical Engineering Research
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• v.44 no.2
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• pp.125-138
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• 2023

The development of AI systems for radiation therapy is important to improve the accuracy, effectiveness, and safety of cancer treatment. The current system has the disadvantage of monitoring patients using CCTV, which can cause errors and mistakes in the treatment process, which can lead to misalignment of radiation. Developed the PMRP system, an AI automation system that uses depth cameras to measure patient's fine movements, segment patient's body into parts, align Z values of depth cameras with Z values, and transmit measured feedback to positioning devices in real time, monitoring errors and treatments. The need for such a system began because the CCTV visual monitoring system could not detect fine movements, Z-direction movements, and body part movements, hindering improvement of radiation therapy performance and increasing the risk of side effects in normal tissues. This study could provide the development of a field of radiotherapy that lags in many parts of the world, along with the economic and social importance of developing an independent platform for radiotherapy devices. This study verified its effectiveness and efficiency with data through phantom experiments, and future studies aim to help improve treatment performance by improving the posture correction mechanism and correcting left and right up and down movements in real time.

• Korean Journal of Applied Biomechanics
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• v.25 no.1
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• pp.113-122
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• 2015

Objective : The purpose of this study was to analyze the foot-pressure distribution of 2D(2 dimensional form) & 3D(3 dimensional form; a customized arch-fit for posture correction) insoles for assessing their biomechanical functionality. Background : Recently there has been increased interest in both foot health and foot pain patients. Analysis of the plantar pressure was often used to solve the problems of the foot displayed by such people as rheumatoid arthritis patients. Method : Subjects who participated in this study were 17 female university students who had no previous injury experience in lower limbs and a normal gait pattern. The shoe size of all subjects was 240 mm. Two models of insoles of 2D(typical flat insole - 2 dimensional form) and 3D(special production - 3 dimensional form) were selected for the test. Using the Pedar-X system and Pedar-X insoles, 4.0 km/h of walking speed, and a compilation of 50 steps walking stages were used to analyze foot-pressure distribution. Results : Results of the foot-pressure distribution and biomechanical functionality on each insole were as follows; analyses of mean plantar pressure, maximum plantar pressure, maximum vertical GRF, and plantar pressure curve shape all showed overall low plantar pressure and GRF. Conclusion : This can be evaluated as an excellent insole for low levels on the plantar pressure and GRF. Therefore, it is possible to conclude that according to this analysis the 3D Customized Arch-fit Insole was better than 2D insole on the basis of these criteria.

• Journal of Korea Entertainment Industry Association
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• v.14 no.3
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• pp.383-392
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• 2020

This study was to compare the effects of joint mobilization, treadmill with insole, and joint mobilization and treadmill with insole on pain, pelvic angle, and foot pressure in patients with sacroiliac joint pain. 24 patients randomly assigned to joint mobilization group(n=8), treadmill with insole group(n=8), or joint mobilization and treadmill with insole group(n=8). Each groups were conducted 30 minutes a day, two days a week for four weeks. Pain was evaluated using visual analogue scale and pelvic angle was measured using palpation meter and foot pressure(fore/rear ratio) was measured using Gateview AFA-50 before intervention and after 4 weeks. All groups were significant differences pain in intragroup(p<.01). In pelvic angle, the joint mobilization group was statistically significant in the anterior tilt only, the joint mobilization and treadmill with insole group showed statistically significant improvement in both anterior and posterior tilt(p<.01), and the treadmill with insole group did not show any statistically significant change(p>.05). Also the joint mobilization and treadmill with insole group were significant differences in foot pressure(p<.01). All the interventions reduce sacroiliac joint pain and joint mobilization and treadmill with insole training are most effective changes in pelvic angle and foot pressure. This study can be used as a basic data for prevention of injury, posture correction and gait training in patients with sacroiliac joint pain, as well as chronic low back pain and plantar pressure problem.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.4
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• pp.570-593
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• 1996

This study was intended to perform the influence of condyle positional change after surgical correction of skeletal Class III malocclusion after BSSRO in 20 patients(males 9, females 11) using computed tomogram that were taken in centric occlusion before, immediate, and long term after surgery and lateral cephalogram that were taken in centric occlusion before, 7 days within the period intermaxillary fixation, 24hour after removing intermaxillary fixation and long term after surgery. 1. Mean intercondylar distance was $84.45{\pm}4.01mm$ and horizontal long axis of condylar angle was $11.89{\pm}5.19^{\circ}$on right, $11.65{\pm}2.09^{\circ}$on left side and condylar lateral poles were located about 12mm and medial poles about 7mm from reference line(AA') on the axial tomograph. Mean intercondylar distance was $84.43{\pm}3.96mm$ and vertical axis angle of condylar angle was $78.72{\pm}3.43^{\circ}$on right, $78.09{\pm}6.12^{\circ}$on left. 2. No statistical significance was found on the condylar change(T2C-T1C) but it had definitive increasing tendency. There was significant decreasing of the distance between both condylar pole and the AA'(p<0.05) during the long term(TLC-T2C). 3. On the lateral cephalogram, no statistical significance was found between immediate after surgery and 24 hours after the removing of intermaxillary fixation but only the lower incisor tip moved forward about 0.33mm(p<0.05). Considering individual relapse rate, mean relapse rate was 1.2% on L1, 5.0% on B, 2.0% on Pog, 9.1% on Gn, 10.3% on Me(p<0.05). 4. There was statistical significance on the influence of the mandibular set-back to the total mandibular relapse(p<0.05). 5. There was no statistical significance on the influence of the mandibular set-back(T2-T1) to the condylar change(T2C-T1C), the condylar change(T2C-T1C, TLC-T2C) to the mandibular total relapse, the pre-operative condylar position to the condylar change(T2C-T1C, TLC-T2C), the pre-operative mandibular posture to the condylar change(T2C-T1C, TLC-T2C)(p>0.05). 6. The result of multiple regression analysis on the influence of the pre-operative condylar position to the total mandibular relapse revealed that the more increasing of intercondylar distance and condylar vertical axis angle and decreasing of condyalr head long axis angle, the more increasing of mandibular horizontal relapse(L1,B,Pog,Gn,Me) on the right side condyle. The same result was founded in the case of horizontal relapse(L1,Me) on the left side condyle.(p<0.05). 7. The result of multiple regression analysis on the influence of the pre-operative condylar position to the pre-operative mandibular posture revealed that the more increasing of intercondylar distance and condylar vertical axis angle and decreasing of condylar head long axis angle, the more increasing of mandibular vertical length on the right side condyle. and increasing of vertical lengh & prognathism on the left side condyle(p<0.05). 8. The result of simple regression analysis on the influence of the pre-operative mandibular posture to the mandibular total relapse revealed that the more increasing of prognathism, the more increasing of mandibular total relapse in B and the more increasing of over-jet the more increasing of mandibular total relapse(p<0.05). Consequently, surgical mandibular repositioning was not significantly influenced to the change of condylar position with condylar reposition method.

• Clinical and Experimental Pediatrics
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• v.48 no.1
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• pp.75-80
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• 2005

Purpose : Internal tibial torsion is prevalent in East Asian countries such as Korea and Japan, where sitting on the floor is common behavior. Internal tibial torsion or excessive lateral tibial torsion may cause esthetical, functional, or psychological problems and also may induce degenerative arthritis in older age. The purpose of this study is to measure the tibial torsion in children of the Jeju area. Methods : Tibial torsion was measured in 1,042 lower extremities of 521 children from one to 12 years of age. The values of transmalleolar angles were analyzed for each age group divided by 6 months. Quadratic and linear regression models were used to fit patterns of changes in mean values of transmalleolar angles. The age at seven, which provides the highest coefficient of determination for quadratic regression analysis, was used as a cut-off point to fit different statistical models. Results : The mean transmalleolar angle was $0.10{\pm}5.79^{\circ}$ in all children,$ 0.90{\pm}5.49^{\circ}$ in males, and $-0.80{\pm}5.97^{\circ}$ in females. The value was $4.25{\pm}4.04$ in 1 year of age, gradually decreased to the lowest level of $-1.98^{\circ}$ in four years and seven months of age, increased again with age until it reached $0.67{\pm}1.10^{\circ}$ at seven years of age, and stayed at that level thereafter. Conclusion : Internal tibial torsion in infancy is known to correct spontaneously in the normal developing process. But in this study, the mean transmalleolar angle in children of Jeju area annually decreased after one year of age; to the lowest angle at four years and seven months of age; increased again gradually to the age of seven; and persisted in that level, about $10^{\circ}$ less than western children, not correcting further thereafter. These findings suggest tibial torsion might be caused by lifestyle, especially sitting on feet. To prevent abnormalities of joints and gaits, early diagnosis of tibial torsion in childhood and posture correction or early treatment when needed, seems to be necessary.