• Physical Therapy Korea
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• v.22 no.3
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• pp.1-11
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• 2015

The purpose of this study was to investigate the effect of lumbar stabilization training and additional thoracic mobilization on pain, proprioception and static balance in patients with chronic low back pain. The subjects of this study were 48 chronic low back pain patients who were randomly allocated to an experimental group 1 ($n_1=16$, lumbar stabilization and thoracic mobilization, thoracic hypomobility), experimental group 2 ($n_2=16$, lumbar stabilization and thoracic mobilization, thoracic normal mobility), and a control group ($n_3=16$, lumbar stabilization, thoracic hypomobility) after a thoracic mobility test. Both experimental groups underwent lumbar stabilization training and additional thoracic mobilization. The control group underwent only lumbar stabilization training. The intervention was performed 3 times per week, 30 minutes each time, for a total of 6 weeks. Thoraco-lumbar joint reposition error was measured using an electrogoniometer and static balance ability was measured using the Tetrax posture analysis system. Subjects' pain level was measured using a 100 mm visual analogue scale. Statistical analyses were performed using a one-way analysis of variance and a paired t-test. Post-hoc testing was carried out with a Bonferroni test. The pain level was significantly lower in both experimental groups compared to the control group. Both experimental groups showed significant reductions in joint reposition error angle (flexion, extension, and side bending) compared to the control group. The static balance level was significantly lower in both experimental groups than in the control group. In summary, lumbar stabilization exercises and additional thoracic mobilization significantly improved the pain level, proprioception, and static balance in patients with chronic low back pain.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.5
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• pp.121-127
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• 2013

When input power is small, nonideal symmetric balance incomplete block design(BIBD) code design is effective in the spectral-amplitude-code(SAC) optical code-division multiple-access (OCDMA) system. But the number of simultaneous users is not sufficient. To overcome this property, we propose 2-D BIBD codes, where nonideal BIBD codes are used as spectral code and ideal BIBD codes are used as spatial codes. Analytical results show that the number of simultaneous users increases significantly.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.6
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• pp.102-110
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• 1996

A new design scheme of a binary decision tree is proposed. In this scheme a binary decision tree is constructed by using genetic algorithm and FCM algorithm. At each node optimal or near-optimal feature subset is selected which optimizes fitness function in genetic algorithm. The fitness function is inversely proportional to classification error, balance between cluster, number of feature used. The binary strings in genetic algorithm determine the feature subset and classification results - error, balance - form fuzzy partition matrix affect reproduction of next genratin. The proposed design scheme is applied to the tire tread patterns and handwriteen alphabetic characters. Experimental results show the usefulness of the proposed scheme.

• Physical Therapy Korea
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• v.21 no.2
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• pp.18-27
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• 2014

The purpose of this study was to examine the effects of dual-task training (cognitive and exercise tasks) on the balance and gait performance of chronic stroke patients. Eighteen subjects with chronic stroke were divided equally into two groups, an experimental group and a control group. Subjects in both groups participated in an exercise program, performing the same tasks, for 45 minutes per day, three times per week for four weeks. The experimental group also performed additional cognitive task. The experimental group showed a more significant improvement than the control group on the Berg Balance Scale, the Timed Up and Go Test, the Korean Activities-Specific Balance Confidence Scale, and the Functional Gait Assessment (p<.05). The cognitive task error rates in the final week were significantly less than in the first week in the experimental group (p<.01). These results suggest that dual-task training for chronic stroke patients is effective in improving balance, gait, and cognitive abilities.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.3
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• pp.95-101
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• 2020

We studied the Implementation and design of inertial sensor that enables to improve performance by reduce the noise of rotor which Angle of inclination. Analyze model equation including motion equation and error, signal processing filter algorithm on high frequency bandwidth with eliminates error using estimation of error coefficient method is was designed and the prototype inertial sensor showed the pick off noise up to 0.2 mV and bias error performance of about 0.06 deg/hr by the experiments. Accordingly, we confirmed that the design of inertial sensor was valid for high rotation.

• PNF and Movement
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• v.8 no.2
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• pp.1-8
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• 2010

Purpose : The purpose of this study was to investigate the effects of proprioceptive exercise (PE) using a trampoline and a balance board on a balance ability after stroke. Method : Sixteen chronic stroke patients participated. Participants were randomly assigned to the PE group or control group (8 experimental, 8 control). All of participants were in-patients at local rehabilitation centre and had been receiving a traditional rehabilitation program, five days a week. The PE group have additionally undergone for four weeks, three days a week, the PE using a trampoline and a balance board under supervision by a physical therapist but control group was not received any additional program except the traditional rehabilitation program. The position sense test used to assess a proprioceptive sense at a knee joint. The Berg Balance Scale (BBS) and the Timed Up & Go (TUG) test to measure the balance ability were carried out before and after the training. Result : After the training the error of position sense at knee joint of PE group significantly decreased compared to the control group. The PE group demonstrated a significant improvement in the scores of the BBS and TUG. Conclusion : The present study suggests that the PE program using a trampoline and balance board may become a useful tool for enhancing a balance ability in chronic stroke patients through the ennced proprioceptive position senses.

• The Journal of Korean Physical Therapy
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• v.23 no.2
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• pp.23-29
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• 2011

Purpose: The purpose of this study was to determine whether there is a relationship between strength balance and joint position sense related to the ankle joint in healthy women. Methods: Twenty-six healthy women were recruited. Isokinetic strength and joint position sense (JPS) were measured using a Biodex System 4 pro Dynamometer and a Biodex Advantage Software Package. Prior to measuring the JPS and isokinetic strength, the dominant foot was determined according to the Waterloo Footedness Questionnaire. After the JPS test, isokinetic strength was evaluated in velocity $60^{\circ}s$, including practice trial ($90^{\circ}s$). Using the measured isokinetic strength, a Strength Balance Index (SBI) was calculated. Results: Relative to the SBI, the degree of imbalance was varied; but there were imbalances. For each starting position, JPS error showed no significant differences (p>0.05). The relationship between SBI and JPS was found during the inversion to eversion process, eversion to inversion, and dorsi flexion to plantar flexion. Conclusion: There are moderate to mild relationships between JPS and SBI during ankle movement. It is suggested that to prevent ankle injuries, strength balance should be considered along with the other potential factors including anatomical alignment, proprioception, and soft tissues problems.

• Journal of Korea Water Resources Association
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• v.50 no.9
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• pp.587-595
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• 2017

Hydraulic characteristics affecting sediment transport capacity due to the weir operations were investigated and developed sediment rating curves for four gaging stations (Nakdong, Gumi, Waegwan, and Jindong) in Nakdong River. Analysis found that the sediment transportaion capability had been decreased and it could be proved from the field measurement records in 2013. Applicabilities of nine sediment transport prediction techniques, which are imbeded in GUIDE program, were examined and adopted for the four gaging stations. Analysis of sediment balance for Nakdong River, including 9 major tributaries, had been carried out with pseudo 2-D numerical model and found that: 1) sedimentation phenomena will be prevailed along the Nakdong River. 2) Engelund-Hansen technique shows the least error in estimation of sediment balance. 3) Engelund-Hansen technique most appropriately describes the sediment characteristics for four gaging stations. 4) Estimated error from the sediment balance for Nakdong River was smaller than the error caused by the estimation of sediment incomming from 9 tributries. Therefore, it is necessary to improve the accuracy of predicting the sediment incomming from the tributaties for better sediment balance analysis.

• Journal of Biomedical Engineering Research
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• v.32 no.1
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• pp.7-14
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• 2011

This study suggested an optimized algorithm for detecting the loss of balance(LOB) in the seated position. And the sensitivity analysis was performed in order to identify the role of each design variable in the algorithm. The LOB algorithm consisted of data processing of measured signals, an internal model of the central nervous system and a control error anomaly(CEA) detector. This study optimized design variables of a CEA detector to obtain improved values of the success rate(SR) of detecting the LOB and the margin time(MT) provided for preventing the falling. Nine healthy adult volunteers were involved in the experiments. All the subjects were asked to balance their body in a predescribed seated posture with the rear legs of a four-legged wooden chair. The ground reaction force from the right leg was measured from the force plate while the accelerations of the chair and the head were measured from a couple of piezoelectric accelerometers. The measured data were processed to predict the LOB using a detection algorithm. Variables S2, h2 and hd are related to the detector: S2 represents a data selecting window, h2 a time shift and hd an operating period of the LOB detection algorithm. S2 was varied from 0.1 to 10 sec with an increment of 0.1 sec, and both h2 and hd were varied from 0.01 to 1.0 sec with an increment of 0.01 sec. It was found that the SR and MT were increased by up to 9.7% and 0.497 sec comparing with the previously published case when the values of S2, h2 and hd were set to 4.5, 0.3 and 0.2 sec, respectively. Also the results of sensitivity analysis showed that S2 and h2 had considerable influence on the SR while these variables were not so sensitive to the MT.

• Journal of the Korean Society of Physical Medicine
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• v.13 no.3
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• pp.27-37
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• 2018

PURPOSE: The purpose of this study was to investigate and evaluate muscle activity and foot pressure during gait, and isokinetic strength and balance in persons with functional ankle instability (FAI). METHODS: Nine healthy subjects (CON, n=9) without FAI and 11 patients (FAI, n=11) with FAI participated in the study after having been screened with an ankle instability instrument and a balance error scoring system. In addition, FAI was classified as non-involved (FAI-N) or involved (FAI-I), and CON was classified as dominant or non-dominant. All subjects were evaluated for isokinetic strength (plantar flexion, dorsiflexion, inversion and eversion of $30^{\circ}/sec$ and $60^{\circ}/sec$), balance (static and dynamic), muscle activity (tibialis anterior, peroneus longus and gastrocnemius) and foot pressure (static and dynamic) during gait. RESULTS: Results showed that plantar flexion (p<.05), dorsiflexion (p<.05), inversion (p<.01) and eversion (p<.00) of $60^{\circ}/sec$ were significantly decreased in FAI-I compared to those in FAI-N and CON. C 90 of static balance with eyes open (p<.01) and closed (p<.00) were significantly increased in FAI compared to those in CON. Forward position of dynamic balance (p<.01) was significantly decreased in FAI compared to that in CON. Gastrocnemius and peroneus longus of dynamic muscle activity (p<.01), left and right weight distribution of static foot pressure (p<.00) and pressure distribution of dynamic foot pressure (p<.00) were significantly decreased in FAI-I compared to those in FAI-N. CONCLUSION: We demonstrated that ankle strength, balance, muscle activity and foot pressure were significantly correlated with FAI.