• Journal of Korean Physical Therapy Science
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• v.18 no.1
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• pp.69-77
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• 2011

Background: The purpose of this study was to assessment of posture sway on static standing in the elderly. Methods: The participants aged 60 to 90 years, were divided into age such 60s, 70s and 80s and with a history of exercise, arthritis and hang on one's stick. Posture sway were analyzed using the computerized BPM system. Each test was repeated three times. All the data were expressed means and standard deviation by using SPSS 12.0 program. Results: The posture sway test according to sex showed that mean balance, sway number and frequency performance were significantly stable in men than in women. All direction frequency, sway area, sway path and max velocity were significantly unstable in 80s than 70s and 60s. The results of the posture sway test according to exercise group, arthritis and hang on one's stick group were showed that mean balance function was significantly stable in exercise group than arthritis and stick groups. The weight was showed significant correlation by mean balance, sway no, frequency, sway area, sway path and max velocity. Sway area and max velocity were not significant correlation by frequency of lateral and left, right anterior and posterior direction. Conclusion: In this study was showed that posture sway was effected from health condition of elderly.

• Journal of the Korean Society of Physical Medicine
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• v.1 no.1
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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.

• The Journal of Korean Physical Therapy
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• v.16 no.1
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• pp.208-246
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• 2004

The purpose of this study was to investigate the effect of aqua exercise program on the static balance of child with mental retardation. The subjects were seven male child and three female child with mental retardation(age ranges from 5 to 6). The subjects were practiced with focusing on the aqua exercise program for 8 weeks, from 7, January 2003 to 28, February 2003. The results of this study were as follows : 1. After the exercise program, the balance of double-stance by BPM was significantly reduced of lateral sway number by $12.2\%$(P<.01) with eyes obstruct. 2. After the exercise program, the balance of double-stance by BPM was significantly reduced of anterior and posterior sway number of left leg by $8.5\%$(P<.05) with eyes obstruct. 3. After the exercise program, the balance of double-stance by BPM was significantly reduced of anterior and posterior sway number of right leg by $8.3\%$(P<.05) with eyes obstruct. 4. After the exercise program, the balance of double-stance by BPM was significantly reduced of lateral sway number by $13.2\%$(P<.01) with eyes open. 5. After the exercise program, the balance of double-stance by BPM was significantly reduced of anterior and posterior sway number of left leg by $10.3\%$(P<.05) with eyes open. 6. After the exercise program, the balance of double-stance by BPM was significantly reduced of anterior and posterior sway number of right leg by $10.3\%$(P<.01) with eyes open. As we can see the results of this study, the aqua exercise program improved the static balance of child with mental retardation. Futhermore, it is reasonable program that can improvability of static balance for the children with mental retardation using aqua exercise program. And then it is necessary to develop much better program than now for the children with mental retardation's health and to provide the adequate pool for their aqua exercise.

• The Journal of Korean Physical Therapy
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• v.17 no.4
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• pp.537-557
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• 2005

The purpose of this study was to investigate the effect of pelvic traction and muscle energy technique(MET) for hemiplegic patients on static standing balance. The scale for static standing balance is measured by using mean balance(%), frequence(Hz), sway area($mm^2$), sway path(mm), max sway velocity(mm/s), ant/post sway angle($^{\circ}$), lateral sway angle($^{\circ}$), sway number, change of pelvic height is measured in relation to the height of ASIS and PSIS. The subjects of this study were thirty hemiplegic patients: 15men and 15 women, with an average ages of 50.80 years. The thirty subjects were divided into 3 group of 10 at random ; ten subjects had pelvic traction after bobath therapy (the pelvic traction group), ten subjects had muscle energy technique after bobath therapy (the MET group), and ten subjects had only bobath therapy (the control group). Static standing balance was measured using BPM (balance performance monitor; data print software version 5.3), pelvic height was measured using height measuring with an adjustable horizontal arm. In order to assure the statistical significant of the result, an one-way ANOVA, the paired t-test, and a person's correlation were applied at the.05 level of significance. The results of this study were as follows: 1) The change in pelvic height were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). 2) The change in affected and non-affected on weight bearing were not statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p>.05). 3) The change in frequency were statistically significant between the MET group, the control group and the pelvic traction group on pre-treatment and post-treatment(p<.05). 4) The change in sway area were statistically significant between the MET group, the control group and the pelvic traction group on pre-treatment and post-treatment(p<.05). 5) The change in sway pa1h were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). 6) The change in max sway velocity were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). 7) The change in ant/post sway angle were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). 8) The change in lateral sway angle were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). 9) The change in sway number were statistically significant between the pelvic traction group, the MET group and the control group on pre-treatment and post-treatment(p<.05). In conclusion, there was a difference between the experimental group and the control group. In the future, we have to study continuously about pelvic traction and muscle energy technique in hemiplegic patients.

• Steel and Composite Structures
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• v.4 no.4
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• pp.317-331
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• 2004

The lateral sway of a multi-storey steel frame should be limited so as to ensure the comfort of the occupants and for the protection of mechanical and architectural systems. This paper investigates the applicability of Schueller's equation for predicting sway of rigid steel frames, and proposes a number of modifications to the equation so that it can produce results that are almost identical to those given by accurate Finite Element (FE) analysis. The behaviour of irregular steel frames has also been studied and proposals are made so that Schueller's Equation can also be used to predict sway of such frames.

• International Journal of Control, Automation, and Systems
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• v.2 no.4
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• pp.435-449
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• 2004

In this paper, a novel anti-sway control system that uses an inclinometer as a sway sensor is investigated. The inclinometer, when compared with a vision system, is very cheap, durable, and easy to maintain, while providing almost the same performance. A number of observers to estimate the angular velocity of the load and the trolley velocity are presented. A state feedback controller with an integrator is designed. After a time-scale analysis, a 1/4-size pilot crane of a rail-mounted quayside crane was constructed. The performance of the proposed control system was verified with a real rubber-tired gantry crane at a container terminal as well as with the constructed pilot crane. Experimental results are provided.

• Journal of the Ergonomics Society of Korea
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• v.5 no.1
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• pp.3-9
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• 1986

This research is aimed at examining age-related changes of postural sway when people stand upright, examining external effects which can be exerted upon the postural sway (experiment 1), and also analyzing specific changing characters of posture-control by sudden impacts (experiment 2). The total number of subjects was 115, who are in twenties through seventies and 75 of them were participated in experiment 2. In experimen 1, the subjects were examined for 25 seconds respectively while standing upright with both feet and with eyes opened, standing upright with both feet and with eyes closed, and standing upright with a single foot and with eyes opened. In experiment 2, only while standing upright with both feet and with eyes opened they were examined for 5 seconds. Main findings were as follows: 1. In the single-foot standing position, the growing older exerted more important effects upon the fluctuation length and area of the center of gravity than in the both-foot standing position. 2. The standard deviation was increasing with age in the fluctuation length and the fluctuation area of the center of gravity. 3. There were no significant differences in daily variation, temperature change, and muscle burdening. 4. The recuperation from the postural sway by external impacts was so slow with age. 5. There were little differences in decrease frequencies among the subjects but younger persons.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.3
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• pp.39-46
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• 2016

Loss of postural stability can possibly lead to slip and fall accidents in the number of workplaces and everyday life. This study was aimed to examine the effects of whole body fatigue and partially limited visual field on the ability of maintaining postural balance during quiet standing. A group of twelve healthy male subjects participated in the experiment. Before and after experiencing the whole body fatigue induced by bicycling exercises, the position coordinates of subject's center of pressure (COP) were obtained under the two levels of visual field condition (i.e., open visual field and limited visual field). Four levels of the whole body fatigue examined were rest, 300watt, 600watt, and 900watt. Position coordinates of COPs measured on a force plate were then converted into the total length of postural sway path in both the medio-lateral (ML) direction and the anterior-posterior (AP) direction. Two-way ANOVA result showed that the length of sway path in the AP direction became significantly larger as the whole body fatigue accumulated. Post-hoc test revealed statistically significant differences between rest and 900watt and between 300watt and 900watt. The significant increase of the sway length was also found when the visual field was partially obstructed by the boxes. In the ML direction, however, there was no statistically significant difference of the postural sway in both the AP and ML directions. The results imply that the ability of maintaining postural stability can be reduced significantly due to such tasks along with whole body fatigue. The postural balance can also be impaired by the limited visual field.

• Journal of the Society of Naval Architects of Korea
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• v.50 no.2
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• pp.69-78
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• 2013

This study is constructed to investigate the sloshing effect on the motions of a two-dimensional rectangular cylinder experimentally and numerically. The modes of motion under consideration are sway and roll, and also experimental cases are divided by two categories; 1-DoF roll motion and 2-DoF motion (Coupling sway and roll). It is found that the sway response is considerably affected by the motion of the fluid, particularly near the sloshing natural frequency, while the roll response changes comparatively small. The dominant mode of motion is analyzed for 2-DoF experiments as well. The measured data for 1-DoF motions is compared with numerical results obtained by the Multi-modal approach. The numerical schemes vary in detail with the number of dominant sloshing modes; i.e. there is a single dominant mode for the Single-dominant method, while the Model 2 method assumes that the first two modes are superior. For the roll motion, numerical results obtained by the two different methods are relatively in good agreement with the experiments, and these two results are similar in most wave frequency range. However, the discrepancies are apparent where the fluid motion is not governed by a single mode. But both of numerical methods over-predict the motion at the vicinity of the sloshing natural frequency. In order to correct the discrepancy, the modal damping needs to be investigated more precisely. Furthermore, another multi-modal approach, such as the Boussinesq-type method, seems to be required in the region of the intermediate liquid.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.20 no.4
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• pp.309-332
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• 2016

Finite element method has been applied to solve the fundamental governing equations of natural convective, electrically conducting, incompressible fluid flow past an infinite vertical plate surrounded by porous medium in presence of thermal radiation, viscous dissipation, Soret and Dufour effects. In this research work, the results of coupled partial differential equations are found numerically by applying finite element technique. The sway of significant parameters such as Soret number, Dufour number, Grashof number for heat and mass transfer, Magnetic field parameter, Thermal radiation parameter, Permeability parameter on velocity, temperature and concentration evaluations in the boundary layer region are examined in detail and the results are shown in graphically. Furthermore, the effect of these parameters on local skin friction coefficient, local Nusselt number and Sherwood numbers is also investigated. A very good agreement is noticed between the present results and previous published works in some limiting cases.