• PNF and Movement
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• 제8권3호
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• pp.39-47
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• 2010

Purpose : The purpose of this study was to investigate the correlations between clinical balance scales and Balance Performance Monitor parameters in patient with adolescent idiopathic scoliosis (AIS). Methods : Twenty AIS subjects (age, $14.26{\pm}1.93yrs$; height, $160.56{\pm}7.98cm$; weight, $47.54{\pm}6.94kg$)were participated in this study. Postural sway(mean balance, sway angle, sway area, sway path, maximal sway velocity) were were evaluated by balance performance monitor. Measurements for clinical balance scales were Functional reach test (both side), the Lateral reach test (both side) and One leg standing test (both legs). Results : The results were as follows. There were positive strong correlation between major curve direction and left-right sway angle, sway path, maximal sway velocity. There were negative strong correlation between the functional reach and left-right sway angle, sway area, sway path, maximal sway velocity. And the lateral reach were also showed negative strong correlation parameters of balance performance monitor. One leg standing were negatively correlated with left-right sway angle, sway path, maximal sway velocity. Conclusion : The clinical balance scales will be useful tools for balance measurements, and basic tools for clinical setting for patient with AIS.

• 대한물리치료과학회지
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• 제10권1호
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• pp.109-121
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• 2003

The purpose of this study was to test the difference of sitting balance control between a normal group and a group of patients with low back pain when their eyes were opened or closed. The 30 subjects of the control group had been chosen from healthy individuals who fit into the pre-designed criteria, and the 30 subjects of the experimental group were composed of the patients with LBP who had their treatment from S hospital from september 1, 2002, to October 30, 2002, and the subjects were measured by static balance test by using a balance performance monitor(BPM). Static balance test was done twice for each subject with his or her eyes opened and closed. Collected data were statistically analyzed by SPSS/PC using unpaired T-Test, Pained T-Test and multiple regression. The results were as follows: 1. In static balance test, normal group did not show statistical significance in sway angle(Anterior, Posterior, left and Right), sway path, sway area and maximal sway velocity, but showed statistical significance in mean balance with eyes opened and eyes dosed(P<.05) 2. In static balance test, LBP group did not show statistical significance in sway angle(Anterior, Posterior, left and Right), mean balance, sway path, sway area and maximal sway velocity with eyes opened and eyes dosed 3. With eyes opened, the comparison between the normal group and the LBP group showed statistical significance in sway angle(Anterior, Posterior, left and Right), mean valance, sway path, sway area and maximal sway velocity(p<.05). With eyes closed, normal group and LBP group did not show statistical significance in sway angle(Anterior and Right), sway area, but showed statistical significance in sway angle(Posterior and Left), mean balance, sway path, sway area and maximal sway velocity(p<.05) In conclusion, there was a significant difference in static sitting balance between normal group and LBP patients group. For future studies, I strongly suggest that researches be done on the treatment with LBP by predicting changes of postures and manipulating them.

• 대한물리의학회지
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• 제1권1호
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• pp.77-92
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• 2006

Purpose : This study was to evaluate the effect of traditional balance training on balance in older adults. Methods : The subjects of this study were thirty elderly over 65 years old. Thirty subjects ranging aged from 66 to 85($74.0{\pm}5.83$) completed the study and participated three times a week for 5weeks. Subjects were assessed by utilizing two different balance measure : Static standing balance was measured by balance performance monitor(BPM). Dynamic balance was measured by timed up and go test(TUG). The scale for static standing balance was measured by using frequence(Hz), sway area($mm^2$), sway path(mm), max sway velocity(mm/s), ant/post sway angle($^{\circ}$), left/right sway angle($^{\circ}$), and sway number. Results : The change in frequency were statistically significant on pre-test and post-test(P<.05), 2. The change in sway area were statistically significant on pre-test and post-test (P<.05), 3. The change in sway path were statistically significant on pre-test and post-test(P<.05), 4. The change in max sway velocity were statistically significant on pre-test and post-test (P<.05), 5. The change in ant/post sway angle were statistically significant on pre-test and post-test (P<.05), 6. The change in left/right sway angle were statistically significant on pre-test and post-test(P<.05), 7. The change in sway number were statistically significant on pre-test and post-test(P<.05), 8. The score on timed up and go test shows statistically significant increase on pre-test and post-test (P<.05). Conclusion : This study suggest that traditional balance training have an effect on balance performance ability for elderly people. Therefore, the traditional balance training is recommended for older adults to improve balance performance ability.

• 한국전문물리치료학회지
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• 제14권4호
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• pp.35-43
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• 2007

The purpose of this study was to compare the static balance in a sitting position between a group with adolescent idiopathic scoliosis (AIS) and a normal aged-matched group. Forty-nine subjects were included in this study. Thirty-one healthy subjects and eighteen AIS subjects were participated. Each group was tested with the Lumbar Trunk Muscle Endurance Test (LTMET) and Balance Performance Monitor (BPM). The parameters for static balance were sway area, sway path, mean balance, maximum velocity, anterior-posterior angle, and left-right angle of each group with eyes opened and closed. Results from the LTMET showed significantly more increase in the normal group than in the AIS group in the flexor and extensor endurance. The BPM tested showed significantly difference beteen the groups in parameters of sitting balance such as maximum velocity and anterior-posterior sway angle. For the AIS subjects, there were no significant differences in all parameters of sitting balance between eyes opened and eyes closed. In comparisons of the groups with eyes opened there were no significant differences in all parameters of sitting balance. In comparisons of the groups with eyes closed there were significant differences in the sway area, maximum velocity, anterior-posterior sway angle and left-right sway angle. These results suggest that the AIS group relies much more on proprioception than on vision, and develops compensatory passive postures of the spine. Further study is needed to measure many AIS patients with morphologic and electromyographic data for clinical application.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2000년도 춘계학술대회논문집
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• pp.64-71
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• 2000

Yard cranes are very useful equipments for handling of heavy containers. But rope-driven yard cranes must have a little of sway and skew motion because ropes are passive mechanical device. So many researches have been concentrated on anti-sway algorithm controlling trolley speed. These approaches require sway angle. But it is very difficult to know sway angle and its derivative. Therefore control algorithm of trolley speed is not practical in general. On the contrary, control strategy using auxiliary rope is very useful to sway control of yard crane because rope length is shorter than quay-side container cranes. In this paper, we derive equations of motion of trolley system which have anti-sway controller to use auxiliary rope. And we propose the control strategy and analyse the behavior of the proposed system.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2000년도 추계학술대회논문집
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• pp.143-151
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• 2000

Yard cranes are very useful equipments for handling of heavy containers. But rope-driven yard cranes must have a little of sway and skew motion because ropes are passive mechanical device. So many researches have been concentrated on anti-sway algorithm controlling trolley speed. These approaches require sway angle. But it is very difficult to know sway angle and its derivative. Therefore control algorithm of trolley speed is not practical in general. On the contrary, control strategy using auxiliary rope is very useful to sway control of yard crane because rope length is shorter than quay-side container cranes. In this paper, we derive equations of motion of trolley system which have anti-sway controller to use auxiliary rope. And we propose the control strategy and analyse the behavior of the proposed system.

• 한국해양공학회지
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• 제19권2호
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• pp.60-66
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• 2005

This paper investigates the relationship between the fleet-angle of the hoisting rope and the swaying and pitching angles of a cargo in container cranes. It is found that for a given disturbance, when the fleet-angle is large, the sway Angle becomes smaller, but the pitching angle becomes larger. Therefore, for a quick suppression of a sway motion, it is desirable to have a large fleet-angle. The compatibility and bifurcation conditions, regarding instability, are characterized.

• 융합신호처리학회논문지
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• 제22권4호
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• pp.171-178
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• 2021

카라반은 외부의 물리적 요인에 쉽게 영향을 받아 탑승자에게 위험한 상황을 초래하는 경우가 많다. 따라서 탑승자의 안정성을 확보하기 위해 스웨이 현상을 사전에 예방할 수 있는 스웨이 저감 장치를 개발할 필요성이 있다. 본 논문에서는 견인차량과 카라반 사이의 Hitch angle을 최소화하는 것을 목표로 한다. 구체적으로는 견인차량과 카라반 각각에 장착된 IMU 센서를 통해 카라반의 초기 불안정성을 감지하고, PID 제어기를 이용하여 Hitch angle, Hitch yaw rate가 Desired hitch angle, Desired hitch yaw rate에 수렴할 수 있도록 제어 값을 산출한다. 산출된 제어 값에 따라 카라반 좌우 브레이크에 다른 제동토크를 생성하여 분배하고 제어한다. 주행 실험을 통해 스웨이 저감 장치의 성능을 검증한 결과, 제어하지 않은 경우보다 Hitch angle이 감소한 것을 확인할 수 있었고, 횡 방향 안정성 향상률은 제어 전에 비해 78.9% 향상된 것을 확인하였다.

• The Journal of Korean Physical Therapy
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• 제13권2호
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• pp.381-397
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• 2001

In the patients with hemiplegia caused by stroke and TBI. postural sway is increased and open displaced laterally over the non-affected leg, reflecting asymmetry in weight bearing on lower extremities during standing balance. Recovery of symmetric weight bearing and postural stability is an important aim in physical therapy. Plastic AFO has been used for hemiplegic patients in order to help their abnormal walking patterns. Past studies have mainly focused on the AFO influences on hemiplegic walking patterns without balance function approaches. The purpose of this study was to identify the immediate effects of plastic AFO and shoes on the static balance in hemiplegic patients. The scale for static balance were weight bearing on affected leg(%), sway area(mm2), sway path(mm), maximal sway velocity(mm/s), anteroposterior sway angle($^{\circ}$ ), and lateral angle($^{\circ}$ ). Seventeen hemiplegic patients participated in this study: 13 men and 4 women, with an average age of 50.18 years. Static balance was measured using BPM(balance performance monitor; dataprint software version 5.3) under four standing condition namely bare-foot standing. standing in shoes, standing with AFO, and standing in shoes with AFO. In order to assure the statistical significance of the results, an one-way ANOVA, the independent t-test. and a pearson's correlation were applied at the .05 level of significant. The results of this study were as follows: 1) There were statistically significant differences in weight bearing(%) on the static balance between affected leg and non-affected leg(p<.01). 2) There were statistically significant differences in sway reverse frequence(Hz) in standing with AFO between affected leg and non-affected leg(p<.05). 3) Sway area(mm2) on standing in shoes with AFO was lower than bare-foot standing(p<.05), Lateral sway angle($^{\circ}$ ) on standing in shoes with AFO was lower than bare-foot standing and standing in shoes(p<.05). 4) Weight bearing in affected leg was not significantly correlated with postural sway.

• International Journal of Control, Automation, and Systems
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• 제1권1호
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• pp.43-53
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• 2003

A modified command shaping control to reduce residual vibrations at a target position and to limit the sway angle of the payload during traveling for container crane systems is investigated. When the maneuvering time is minimized, a large transient amplitude and steady state oscillations may occur inherently. Since a large swing of the payload during the transfer is dangerous, the control objective is to transfer a payload to the desired place as quickly as possible while limiting the swing angle of the payload during the transfer. The conventional shapers have been enhanced by adding one more constraint to limit intermediate sway angles of the payload. The developed method is shown to be more effective than other conventional shapers for prevention of an excessive transient sway. Computer simulation results are provided.