• Journal of Korean Academy of Nursing
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• v.22 no.3
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• pp.325-336
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• 1992

The purpose of this study was to determine the effect of exercise training on the length and circumference of atrophied muscles to see whether improvement in restoring the atrophied muscle mass, of either length or circumference growth could be induced through exercise training. Adult female Wistar rats were maintained for 14 days with hindlimb suspension. Rats were then assigned randomly to a sedentary group or training group. The length and circumference of both atrophied soleus and plantaris muscle for the training and sedentary groups following hindlimb suspension were compared with those of a control group. Length and circumference of both atrophied soleus and plantaris muscle in trained group was compared with those in the sedentary group. The results can be summarized as follows ; 1) Atrophy of soleus and plantaris muscle was induced with hindlimb suspension. 2) The circumference of both the soleus and plantaris muscle following hindlimb suspension was reduced to 51. 72%, 66.67% respectively compared to the control group. The length of both the soleus and plantaris muscle following hindlimb suspension did not show any difference compared to the control group. 3) There was no difference in length for either the atrophied soleus or plantaris muscle between the trained and the sedentary group during recovery from hindlimb suspension. 4) The circumference of both the atrophied soleus and plantaris muscle did not return to normal in the sedentary group, however, the circumference of both the atrophied soleus and plantaris muscle were significantly greater than of the control in the trained group, 14.22% and 9.38% respectively. 5) The circumference of both the atrophied soleus and plantaris muscle in the trained group was significantly larger than that of both muscles in the sedentary group at day 28 of recovery. From these results, it can be suggested that improvement in restoring the atrophied muscle mass through exercise training might be induced by growth of the muscle circumference.

• Journal of Korean Academy of Nursing
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• v.21 no.3
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• pp.281-294
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• 1991

The purpose of this study was to determine the amount of soleus muscle atrophy in rats due to 28 days of decreased activity induced by hindlimb suspension, to observe the restoration of mass and relative muscle weight of the atrophied soleus muscle at day 28 of recovery to control value, and to compare the effect of run training on the mass and relative muscle weight of the atrophied soleus muscle at day 28 of recovery with that of sedentary rats. Adult female Wistar rats were maintained for 28 days with hindlimb suspension. Rats were then assigned randomly to a cage sedentary or running group. Soleus muscle mass and relative muscle weight following hindlimb suspension were compared with a control value. The soleus muscle mass and relative muscle weight of the running and cage sedentary groups following hindlimb suspension were compared with those of a control group. Soleus muscle mass and relative muscle weight of the run training group were compared with those of cage sedentary group. The results obtained were as follows : 1. Soleus muscle mass and relative muscle weight was reduced to 53.28% and 51.11% respectively by hindlimb suspension. 2. Soleus muscle mass and relative muscle weight of the training group t day 28 of recovery was restored to the control value. 3. Soleus muscle mass of the training group was greater than that of the cage sedentary group by 6.6% without statistical significance at day 28 of recovery. 4. Relative soleus muscle weight of the traning group was significantly greater than that of the cage sedentary group by 15.79% From these results, it may be concluded that run training during the posthypokinetic period facilitates the recovery of the atrophied soleus muscle mass of rats.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.384-388
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• 1996

The closed-loop system modeling of an Active/semiactive suspension system has been accomplished through an artificial neural Networks. The 7DOF full model as the system equation of motion has been derived and the output feedback linear quadratic regulator has been designed for the control purpose. For the neural networks training set of a sample data has been obtained through the computer simulation. A 7DOF full model with LQR controller simulated under the several road conditions such as sinusoidal bumps and the rectangular bumps. A general multilayer perceptron neural network is used for the dynamic modeling and the target outputs are feedback to the input layer. The Backpropagation method is used as the training algorithm. The modeling of system and the model validation have been shown through computer simulations.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.7
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• pp.29-38
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• 1997

A closed-loop system modeling of an active/semiactive suspension system has been accomplished through an artificial neural network. A 7DOF full model as a system's equation of motion has been derived and an output feedback linear quadratic regulator has been designed for control purpose. A training set of a sample data has been obtained through a computer simulation. A 7DOF full model with LQR controller simulated under several road conditions such as sinusoidal bumps and rectangular bumps. A general multilayer perceptron neural network is used for dynamic modeling and target outputs are fedback to the a layer. A backpropagation method is used as a training algorithm. Model validation of new dataset have been shown through computer simulations.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.295-298
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• 1996

In this paper, a self-tuning optimal control algorithm is proposed to retain the optimal performance of an active suspension system, when the vehicle has some time varying parameters and parameter uncertainties. We consider a 2 DOF time-varying quarter car model which has the parameter variation of sprung mass, suspension spring constant and suspension damping constant. Instead of solving algebraic riccati equation on line, we propose a neural network approach as an alternative. The optimal feedback gains obtained from the off line computation, according to parameter variations, are used as the neural network training data. When the active suspension system is on, the parameters are identified by the recursive least square method and the trained neural network controller designer finds the proper optimal feedback gains. The simulation results are represented and discussed.

• Journal of Digital Convergence
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• v.18 no.2
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• pp.483-487
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• 2020

In this study, the effects of suspension training according to the types of ground. Fourteen healthy male college students measured for the characteristics of core muscle activity in suspension training on two different types of grounds, normal flat and unstable ground using a gym ball. EMG (Electromyography) was exploited to measure the activity of the core muscles according to the types of the ground. Muscle activity of the abdominal muscles, external oblique muscles, internal oblique muscles, and lower lumbar standing muscles was measured. The variables in analyses were measured by the means of % MVC method to standardize the EMG signal according to the ground type for each core muscle. In order to verify the differences in core muscles according to the type of ground the paired t-tests were performed at the significance level of 0.05 (p<.05). As a result of measuring the activity of the core muscles according to the various types of grounds, the difference between muscle characteristics obtained in two different grounds did not appear to be statistically significant. However, the result is an important clue to reconsider the notion that the training effect on the unstable ground is generally superior to the effect on the stable ground in the core muscle training. The type of ground in the core muscle training has been found not to significantly affect the muscle activation according to the results of this study. Regardless of the type of exercise program, hence, the difference in muscle activation will not be insignificant even with the standardized program strengthening core muscles.

• Journal of Korean Academy of Nursing
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• v.27 no.1
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• pp.96-108
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• 1997

The purpose of this study was to determine the effect of endurance training prior to occurrence of muscle atrophy on the mass, myofibrillar protein content and fiber crossectional area of atrophied hindlimb muscles of rats. Adult female Wistar rats were trained prior to occurrence of muscle atrophy induced by hindlimb suspension. Training began on the 1st day for 10min /day at 15m /min on a 0% grade, training exercise increased daily in time and intensity so that by the 4th week rats were running 60min /day, at 34m /min on a i3.5% grade. Wet weight and relative weight of soleus, plantaris and gastrocnemius muscle decreased significantly after seven days of hindlimb suspension. Wet weight and relative weight of soleus tended to increase and that of plantaris and gastrocnemius tended to decrease in the exercise group as compared to the control group. Myofibrillar protein content of soleus and gastrocnemius tended to increase and that of plantaris tended to decrease in the endurance trained group as compared to the control group. Fiber crossectional area of Type I, II fiber in soleus and plantaris muscle tended to increase in the exercise group as compared to the control group. Wet weight and relative weight of soleus. plantaris and gastrocnemius decreased significantly, myofibrillar protein content of soleus, plantaris and gastrocnemius increased in hindlimb suspended rats following endurance training as compared to the control group. There was no change in fiber type percentage and crossectional area of type I and II fiber in soleus muscle and that of type I and IIfiber in plantaris muscle decreased in the hindlimb suspended rats following endurance training as compared to the control group. Wet weight and relative weight of soleus and plantaris tended to increase, that of gastrocnemius increased significantly, myofibrillar protein content of soleus and plantaris muscle increased significantly and that of gastrocnemius tended to increase in the hindlimb suspended rats following endurance training as compared to sedentary rats following endurance training. Crossectional area of type I fiber of soleus muscle tended to increase. that of type I fiber of plantaris muscle increased significantly and that of type II fiber tended to increase in hindlimb suspended rats following endurance training as compared to sedentary rats following endurance training. The results suggest that endurance training prior to occurrence of muscle atrophy can attenuate the decrease of mass, myofibrillar protein content and fiber crossectional area induced by hindlimb suspension.

• PNF and Movement
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• v.18 no.3
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• pp.315-321
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• 2020

Purpose: Recent studies have indicated that applying different inclination angles and suspension devices could be a useful way of performing exercises that include the co-activation of the trunk muscles. Present study was to examine the influences of changes in the inclination angle during trunk muscle activity while engaging in a bridge exercise with a suspension device. Methods: 18 healthy, physically active male volunteers completed three trunk inclination angles (15°, 30°, and 45°) for bridge exercise variations. The surface electromyography responses of the rectus abdominis, internal oblique (IO), erector spinae (ES), and rectus femoris (RF), as well as the subjective difficulty (Borg RPE score), were investigated during these bridge exercises. Results: The bridge with a 45° inclination angle suspension significantly increased the muscular activities of the RA and RF and increased the Borg RPE scores (p<0.05). The bridge with a 15° suspension significantly elevated the ES activities when compared to the other conditions. Conclusion: The present study demonstrated that a higher inclination angle could not activate the overall trunk muscles during the bridge exercise. The RA and RF produced greater activation during the bridge exercise with the higher inclination angle. On the other hand, the activities of the erector spine were greater during the bridge exercise with the lower inclination angle. The present study suggests that applying a low trunk inclination angle for the supine bridge exercise is suitable for activating the erector spine muscles.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.4
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• pp.637-645
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• 2013

PURPOSE: The purpose of this study was to examine the effect of using a suspension device for arm reaching activity on trunk stability and gross motor function of children with spastic diplegia cerebral palsy. METHODS: The subject in this study consisted of 11, GMFCS(Gross Motor Function Classification System) III~IV children with spastic diplegia cerebral palsy, all of whom agreed to participate in the study. All subjects were divided into two groups: the experimental group using a suspension device, and the control group using no suspension device. For each group, a thirty-minute intervention was done twice per week during 8 weeks. Before and after intervention, each test was measured using TIS(Trunk Impairment Scale), GMFM (Gross Motor Function Measure) and PRT(Pediatric Reaching Test) to change trunk stability, gross motor function and arm reaching activity. The data were analyzed with the Wilcoxon signed rank test. RESULT: All two groups had a meaningful increase in GMFM-Sit data measured before and after intervention. The experimental group had a significant increase from an average of 78.83 to an average of 84.83 in GMFM-Crawling. For both groups, there was a substantial increase in the change in sitting position and arm reaching. CONCLUSION: According to the results of this study, the arm reaching activity using suspension device had an effect on trunk stability and gross motor function and it changed arm reaching activity.

• Journal of Korean Academy of Nursing Administration
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• v.13 no.2
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• pp.231-241
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• 2007

Purpose: The purpose of this study was to identify the effects of nurse's internal marketing on job satisfaction, turnover intention, and customer orientation. Method: The subjects were 559 nurses were working in 3 general hospitals. The data were collected from October 20 to November 15, 2006. For data analysis, descriptive statistics, Pearson correlation coefficient, stepwise multiple regression were used. Results: The mean score of the total internal marketing was 2.68, communication 3.03, vacation and suspension from office 2.64, education and training 2.60, reward system 2.56, work environment 2.53, and employment benefits 2.38, total job satisfaction was 2.96, turnover intention was 3.10, and customer orientation was 3.76. 'Internal marketing', and total subcategories of internal marketing were positively related to job satisfaction. 'Internal marketing', and total subcategories of internal marketing were negatively related to turnover intention. 'Internal marketing', 'communication', 'vacation and suspension from office', 'education and training', and 'work environment' were positively related to customer orientation. Conclusion: Through this results, to increase job satisfaction and customer orientation and to decrease turnover intention, it is necessary to concentrate on improving internal communication and reward system in the internal marketing strategy.