• Journal of the Korean Society of Physical Medicine
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• v.12 no.2
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• pp.21-31
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• 2017

PURPOSE: The purpose of this study was to identify whether backward walking exercise was more effective than conventional physical therapy for balance and gait in hemiplegic stroke patients. METHODS: Eighteen patients with chronic stroke were randomly assigned to the experimental (n=9) or control (n=9) group. The experimental and control group performed backward walking exercise and conventional physical therapy, respectively, for 8 weeks. Stability Index (SI) and Weight Distribution Index (WDI) during standing were assessed using the Tetrax Balance System. The Timed Up and Go (TUG) test and Korean version of the Berg Balance Scale (K-BBS) were used to evaluate balance and fall risk. Walking speed, stride length, and step length on the affected side were measured using the 10-Meter Walk and ink foot printing tests. Wilcoxon signed-rank and Mann-Whitney U tests were used for within- and between- group comparisons, respectively. RESULTS: The experimental group showed significantly higher changes in SI (p<.01), WDI (p<.01), TUG (p<.001), and BBS score (p<.001) following intervention compared with the control group. The experimental group also showed significantly greater improvements in walking speed (p<.01), stride length (p<.001), and step length on the affected side (p<.001) after intervention compared with the control group. CONCLUSION: Backward walking exercise is an effective intervention to improve balance and gait in hemiplegic stroke patients.

• PNF and Movement
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• v.16 no.3
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• pp.355-363
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• 2018

Purpose: The purpose of this study was to obtain detailed and quantified data concerning the effects of plantarflexor muscle fatigue induced in the non-paretic side on the spatial and temporal gait parameters of the bilateral lower extremities during walking in stroke patients. Methods: This study was conducted on 20 patients with chronic stroke. The load contraction fatigue test was applied to induce muscle fatigue in the non-paretic plantarflexor muscle. Step length, stride length, double support, gait velocity and cadence, and functional ambulatory profile (FAP) score in the bilateral lower extremities were measured using a gait analysis system in order to investigate changes in temporal and spatial gait parameters caused by muscle fatigue on the non-paretic side. The statistical significance of the results was evaluated using a paired t-test. Results: A review of the results for gait parameters revealed a significant increase in double support (p<0.05) and a significant decrease in step length, stride length, gait velocity and cadence, and FAP score (p<0.05). Conclusion: These results indicate that the muscle fatigue in the non-paretic side of the stroke patients also affected the paretic side, which led to a decrease in gait functions. This implies a necessity to perform exercise or training programs in a range of clinical aspects not causing muscle fatigue.

• PNF and Movement
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• v.18 no.3
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• pp.383-392
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• 2020

Purpose: Balance and gait dysfunction caused by aging affect elderly individuals' independent life, which, in turn, can reduce their overall quality of life. The purpose of this study is to compare the differences in the vestibular function of healthy elderly and young adults based on the subjective visual vertical (SVV) test as well as to compare and analyze the gait ability between these two groups to study the differences and association between vestibular, dizziness, and balance ability. Methods: The subjects were 18 young and 16 elderly adults with no neurological or musculoskeletal damage. To evaluate vestibular function, a subjective visual vertical test was performed. To evaluate the gait function, the step time, step length, stride length, stance phase ratio, and swing phase ratio were measured. Balance was evaluated using the Berg Balance Scale (BBS), and dizziness was evaluated using a dizziness handicap inventory (DHI). Results: There were significant differences in the SVV, BBS, and DHI between the young and elderly adults (p < 0.05). The gait variables of the older adults were all significantly different (except for the swing phase ratio) than those of the young adults (p < 0.05). As the result of correlation analysis, the SVV values of the young adults showed a significant negative correlation with step length and stride length (p < 0.05), while the SVV values of the elderly adults only showed a significant positive correlation with the DHI (p < 0.05). Conclusion: The elderly appeared to show a decrease in vestibular function when compared to the young adults, and it is thought that walking and balance function declined, while dizziness increased. Moreover, it is believed that these results can be used as basic data for vestibular rehabilitation in the future.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.1
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• pp.91-99
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• 2022

Purpose : The goal of this study is to examine the effect of robot assisted gait training (RAGT) on the kinematic factors (temporospatial gait parameters, gait cycle ratio, and gait line length) of gait in stroke patients. Methods : The subjects of this study were 24 stroke patients selected by inclusion criteria. Participants were randomly allocated to two groups: robot assisted gait training (n=11) and general neurological physical therapy group (n=11). In the robot-assisted gait training group, robot-assisted gait training was mediated for 30 minutes a day in addition to general neurological physical therapy. The general neurological physical therapy group was mediated by general neurological physical therapy for 30 minutes a day in addition to general neurological physical therapy. The number of interventions was 5 times a week for 5 weeks. In order to compare the kinematic factors of walking between the two groups, gait analysis was performed before and after 5 weeks of training using the Zebris gait analysis system. Results : As a result of the gait analysis of the two groups, there were significant differences in temporospatial gait variables (step length, stride length, step width, step time, stride time), gait cycle ratio (swing phase, stance phase) and gait line length. However, there was no significant difference in the cadence (temporospatial gait parameters) in the robot assisted gait training group compared to general neurological physical therapy group. Conclusion : It is considered to be a useful treatment for stroke patients to promote the recovery of gait function in stroke patients. Based on the results of this study, continuous robot assisted gait training treatment is considered to have a positive effect on gait ability, the goal of stroke rehabilitation. In the future, additional studies should be conducted on many subjects of stroke patients, the kinematic factors of the legs according to the severity of stroke and treatment period, and the effect of gait training.

• Health Policy and Management
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• v.10 no.3
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• pp.88-107
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• 2000

The Alcoholics Anonymous(AA) program has been known to be effective in many countries in helping alcoholics to stop drinking and to change their attitudes, beliefs, and behaviors. In this study, we examined AA activities among Korean AA members and measured the self-evaluated physical, social, and mental changes following the entry into the AA program. Out of identified 300 AA members who were attending 18 different AA group meetings at the time of the survey, 207 completed the self-administered questionnaire(response rate of 69.0%). T-test and ANOVA were used to compare the scores of physica(4-items), social(4-items), and menta(10-items) changes according to the level of AA activities. The proportion of the respondents who practiced the 11th step (meditation) or the 12th step (take alcoholics to a meeting after carrying messages) on the regular basis was 66.6% and 37.2%, respectively. The average time spent in meditation per week was $4.8{\pm}5.47$ hours. The length of participation in AA meetings has significantly positive impact on the average score of changes in all the 3 health states; physical(p<.01), social(p<.05), and mental states(p<.01). Also, practicing the 11th step was significantly associated with improvement of social(p<.01) and mental(p<.05), while practicing the 12th step improved only mental states(p<.01). Our findings demonstrated that not only the length of participation in AA meetings but also the practice of regular meditation(11th step) and taking alcoholics to an AA meeting after carrying messages(12th step) are very important for AA members, and lead to great positive changes in physical, social, and mental states following entry into the AA program.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.9
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• pp.2463-2476
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• 1994

Local mean fluctuating velocity components were measured in the separating and reattaching axisymmetrc region of turbulent boundary layer over the wall of convex cylinders placed in a water tunnel by using 2-color 4-beam fiber optics laser Doppler velocimetry. Measurements were made with three different diameters of cylinders with four different diameters of cylinders with four different diameter of the obstructions. The range of Reynolds number based on step height was between 5,000 to 25,200. The study demonstrates that the reattachment length decreases with decreasing cylinder radius and is always shorter than that for the two-dimensional backward-facing step flow at the condition of the same step height. It was also observed that the turbulent kinetic energy in the recirculating region increases with an increases in the radius of convex curvature. The measured velocity field suggests that the transverse curvature can effect definitely the formation of corner eddy.

• Communications for Statistical Applications and Methods
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• v.22 no.5
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• pp.463-473
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• 2015

We consider a nonparametric AR(1) model with nonparametric ARCH(1) errors. In order to estimate the unknown function of the ARCH part, we apply the stationary bootstrap procedure, which is characterized by geometrically distributed random length of bootstrap blocks and has the advantage of capturing the dependence structure of the original data. The proposed method is composed of four steps: the first step estimates the AR part by a typical kernel smoothing to calculate AR residuals, the second step estimates the ARCH part via the Nadaraya-Watson kernel from the AR residuals to compute ARCH residuals, the third step applies the stationary bootstrap procedure to the ARCH residuals, and the fourth step defines the stationary bootstrapped Nadaraya-Watson estimator for the ARCH function with the stationary bootstrapped residuals. We prove the asymptotic validity of the stationary bootstrap estimator for the unknown ARCH function by showing the same limiting distribution as the Nadaraya-Watson estimator in the second step.

• Journal of IKEEE
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• v.6 no.2 s.11
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• pp.111-118
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• 2002

In this paper, we present a variable block method to reduce additive computational requirements in determining step-size of variable step-size LMS (VS-LMS) algorithms. The block length is inversely proportional to the changing of step-size in VS-LMS algorithm. The technique reduces computational requirements of the conventional VS-LMS algorithms without a degradation of performance in convergence rate and steady state error. And a method for deriving initial step-size, when the input is zero mean, white Gaussian sequence, is proposed. For demonstrating the good performances of the proposed method, simulation results are compared with the conventional variable step-size algorithms in convergence speed and computational requirements.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.4C
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• pp.365-373
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• 2003

In this paper, we design a versatle RS decoder which can decode RS codes of any block length n as well as any message length k, based on a modified Euclid's algorithm (MEA). This unique feature is favorable for a shortened RS code of any block length it eliminates the need to insert zeros before decoding a shortened RS code. Furthermore, the value of error correcting capability t can be changed in real time at every codeword block. Thus, when a return channel is available, the error correcting capability can be adaptiverly altered according to channel state. The decoder permits 4-step pipelined processing : (1) syndrome calculation (2) MEA block (3) error magnitude calculation (4) decoder failure check. Each step is designed to form a structure suitable for decoding a RS code with varying block length. A new architecture is proposed for a MEA block in step (2) and an architecture of outputting in reversed order is employed for a polynomial evaluation in step (3). To maintain to throughput rate with less circuitry, the MEA block uses not only a multiplexing and recursive technique but also an overclocking technique. The adaptive RS decoder over GF($2^8$) with the maximal error correcting capability of 10 has been designed in VHDL, and successfully synthesized in a FPGA.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.1
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• pp.93-102
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• 1999

In this paper, we propose a data model and a retrieval method for content-based video query After partitioning a video into frame sets of same length which is called video-window, each video-window can be mapped to a point in a multidimensional space. A video can be represented a trajectory by connection of neighboring video-window in a multidimensional space. The similarity between two video-windows is defined as the euclidean distance of two points in multidimensional space, and the similarity between two video segments of arbitrary length is obtained by comparing corresponding trajectory. A new retrieval method with filtering and refinement step if developed, which return correct results and makes retrieval speed increase by 4.7 times approximately in comparison to a method without filtering and refinement step.