• Journal of the Korean Society of Physical Medicine
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• v.18 no.2
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• pp.61-70
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• 2023

PURPOSE: This study evaluated an intrinsic foot strengthening exercise method for flat feet by comparing the effects of intrinsic exercises on a stable surface and intrinsic exercises on an unstable surface. METHODS: Twenty-four people with flat feet were divided into two groups. The control group performed short foot exercises and toe towel curl exercises on the stable support surface. The experimental group performed short foot exercises and toe towel curl exercises on an unstable support surface using Aerostep. The navicular drop test, and the static and dynamic balance were measured before and after the intervention. RESULTS: In the experimental and control groups, there was a significant difference in the navicular drop test and static balance before and after the intervention (p < .05). On the other hand, there was no significant difference between the two groups (p > .05). In the dynamic balance, the experimental group showed significant differences in all directions after the intervention (p < .05). The control group showed significant differences in the postero-lateral direction and posteromedial direction (p < .05). In particular, in the forward direction, the experimental group had a more significant change than the control group (p < .05). CONCLUSION: Intrinsic foot muscle strengthening exercises performed on unstable surfaces can be an effective clinical exercise method to improve the dynamic balance ability of people with flat feet.

• Journal of Digital Convergence
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• v.12 no.7
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• pp.411-418
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• 2014

This study, in order to establish the effect of three exercise groups on the static and dynamic balancing abilities and the muscular activity, targeting adult males aged 20-29, assigned 15 men to each aquatic exercise group, trunk stabilization exercise group, and balance exercise group. The study was conducted from June, 2013 to August, 2013, and measured and compared the balancing ability and the muscle activity(tibialis anterior and gastrocnemius muscle) of the participants after performing intervention for 30 minutes a day, 3 days a week, for 6 weeks. As a result, on the comparison between before and after the intervention, there were significant differences in changes of the surface area and the whole path length in all the three groups(p<.05)(p<.01), and also on the dynamic balance, there was a significant difference in change of limited of stability(p<.05)(p<.01). On change of the muscle activity of tibialis anterior, both left and right sides showed statistically significant differences in all the three groups(p<.05)(p<.01), and gastrocnemius muscle showed a statistically significant difference in all the three groups except for the left side of the trunk stabilization exercise group(p<.05)(p<.01). It could be established that aquatic exercise is effective for improvement of the balancing ability and increase of the muscular activity, and we intend to propose specific aquatic exercise program development by conducting a study to determine the objective effect of aquatic exercise on the elderly or patients who have a poor balancing ability.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.419-424
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• 2012

This paper discusses the state-of-the-art techniques in real-time state estimation for the Smart Microgrids. The most popular method used in traditional power system state estimation is a Weighted Least Square(WLS) algorithm which is based on Maximum Likelihood(ML) estimation under the assumption of static system state being a set of deterministic variables. In this paper, we present a survey of dynamic state estimation techniques for Smart Microgrids based on Belief Propagation (BP) when the system state is a set of stochastic variables. The measurements are often too sparse to fulfill the system observability in the distribution network of microgrids. The BP algorithm calculates posterior distributions of the state variables for real-time sparse measurements. Smart Microgrids are modeled as a factor graph suitable for characterizing the linear correlations among the state variables. The state estimator performs the BP algorithm on the factor graph based the stochastic model. The factor graph model can integrate new models for solar and wind correlation. It provides the Smart Microgrids with a way of integrating the distributed renewable energy generation. Our study on Smart Microgrid state estimation can be extended to the estimation of unbalanced three phase distribution systems as well as the optimal placement of smart meters.

• Journal of the Korea Society of Computer and Information
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• v.13 no.1
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• pp.109-116
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• 2008

Even though many studies on parallel rendering based on PC clusters have been done. most of those did not cope with non-uniform scenes, where locations of 3D models are biased. In this work. we have built a PC cluster system with POV-Ray, a free rendering software on the public domain, and developed an adaptive load balancing scheme to optimize the parallel efficiency Especially, we noticed that a frame of 3D animation are closely coherent with adjacent frames. and thus we could estimate distribution of computation amount, based on the computation time of previous frame. The experimental results with 2 real animation data show that the proposed scheme reduces by 40% of execution time compared to the simple static partitioning scheme.

• The KIPS Transactions:PartC
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• v.19C no.2
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• pp.135-144
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• 2012

All the servers in a traditional server cluster environment are kept On. If the request load reaches to the maximum, we exploit its maximum possible performance, otherwise, we exploit only some portion of maximum possible performance so that the efficiency of server power consumption becomes low. We can improve the efficiency of power consumption by controlling power mode of servers according to load situation, that is, by making On only minimum number of servers needed to handle current load while making Off the remaining servers. In the existing power mode control method, they used a static policy to decide server power mode at a fixed time interval so that it cannot adapt well to the dynamically changing load situation. In order to improve the existing method, we propose a dynamic server power control algorithm. In the proposed method, we keep the history of server power consumption and, based on it, predict whether power consumption increases in the near future. Based on this prediction, we dynamically change the time interval to decide server power mode. We performed experiments with a cluster of 30 PCs. Experimental results show that our proposed method keeps the same performance while reducing 29% of power consumption compared to the existing method. In addition, our proposed method allows to increase the average CPU utilization by 66%.

• The Journal of the Korea Contents Association
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• v.11 no.3
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• pp.281-292
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• 2011

In this study, for examining an effect of lower limbs' muscle activity on balance capability when applying sprinter pattern among the PNF, the experiment was conducted as followed. Under the object of 24 people diagnosed by hemiplegia, they were divided into control group and experimental group and the experiment was conducted on the experimental group, three times per a week for six weeks. Experimental group received Sprinter pattern of combined PNF upper extremity and lower extremity pattern. For the lower limbs' muscle activity, effective values of Vastus medialis laterails, medial lateral hamstrings, lateral gastrocnemius' action potential were analyzed. The balance ability tests was conducted with FICSIT-4, FSST and MTD-Balance system. For the significance test of control group and experimental group for measuring time by exercise application method, two-way repeated measure ANOVA was conducted and for the significance test among the groups by each measuring time, independent t-test was conducted. Also, for examining the correlation among the measuring item, pearson correlation was used for the analysis. As the result, the application of sprinter pattern increased muscle activity of lower limbs in paretic side and improve static and dynamic balance ability effectively. Therefore, it will be necessary to develop new intervention by combining active application of the therapeutic intervention program for lower limbs' effective muscle mobilizing in paretic side with various exercising patterns.