• 한국농공학회논문집
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• 제46권7호
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• pp.35-44
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• 2004

In this study, a ventilation model was developed to determine a ventilation rate for the balance of heat, moisture and $CO_{2}$ in a mushroom house. Internal and external temperature, relative humidity and $CO_{2}$ concentration were measured and used to validate the ventilation model. The effects of various environmental factors on physiological responses of mushroom were also investigated. The verified model was simulated under the observed ventilation rates with a difference of$ 0.001{\~}0.065\;m^{3}{\cdot}S^{-1}$ (relative error of $0.3{\~}18.9\%$) when external temperature varied 22.5 to $24.8^{circ}C$ and average ventilation rates was $0.35m^{3}{\cdot}S^{-1}$. The optimal conditions for mushroom growth (internal temperature $22 ^{circ}C$, relative humidity $80\%$, $CO_{2}$ concentration 1,000 ppm) were used for the model application with external temperature, relative humidity and $CO_{2}$ concentration of $27.5{\~}33.5^{circ}C$, $60\%$, and 355 ppm, respectively. Thermal balance was a important factor for an optimum ventilation up to the external temperature of $32^{circ}C$, while $CO_{2}$ concentration balance was more important over $32^{circ}C$. This suggests that humidification for moisture balance is required to maintain temperature and $CO_{2}$ concentration at an optimal level by ventilation in a mushroom house.

• 로봇학회논문지
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• 제8권2호
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• pp.67-74
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• 2013

This paper presents interaction force control between a balancing robot and a human operator. The balancing robot has two wheels to generate movements on the plane. Since the balancing robot is based on position control, the robot tries to maintain a desired angle to be zero when an external force is applied. This leads to the instability of the system. Thus a hybrid force control method is employed to react the external force from the operator to guide the balancing robot to the desired position by a human operator. Therefore, when an operator applies a force to the robot, desired balancing angles should be modified to maintain stable balance. To maintain stable balance under an external force, suitable desired balancing angles are determined along with force magnitudes applied by the operator through experimental studies. Experimental studies confirm the functionality of the proposed method.

• 대한통합의학회지
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• 제3권4호
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• pp.43-51
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• 2015

Purpose : This study examines the effect of trunk stabilization program on the body balance, lung capacity, and muscular activity of the rectus abdominis and external oblique of healthy adults. Method : A survey was conducted for 20 students of K University located in the city of Y in Gyeongsangbuk-do Province of Korea. The trunk stabilization program consisted of a hollowing exercise, curl-up, bridging exercise, and birddog exercise. This was performed 14 times in total (7 times a week for two weeks). For analysis, good balance was used to measure both static and dynamic balancing ability. A peak flow meter was used to measure the maximum expiratory flow, and MP150 was used to measure muscular activity of the rectus abdominis and external oblique. Result : After the trunk stabilization program, the participants showed a difference in score and time taken to achieve static and dynamic balance, and muscular activity of the rectus abdominis and external oblique at a statistically significant level (p<0.05). However, no significant difference was observed in the left-to-right distance and front-to-back distance in a dynamic balance, and the lung capacity (p>0.05). Conclusion : The results showed that the trunk stabilization program was effective in enhancing both static and dynamic balancing ability and muscular activity. It also increased the lung capacity although the change was not at a statistically significant level.

• 대한물리의학회지
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• 제2권2호
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• pp.143-150
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• 2007

Purpose : This article was a quasi-experimental study that applies to external -feedback weight-bearing training among hemiplegic patients with a stoke. Methods : It examined whether position sense and balance can improve fall efficacy and prevent a fall. The subject of study was divided in two; Experimental group had 18 people and control group had 16 people. It took 8 weeks to finish training. Experimental group provides external-feedback weight-bearing training for ten minutes after neurological treatment for 20 minutes and control group provides nerves treatment for 30 minutes. To find the effect of a fall assessed position sense, balance and fall efficacy of the lower limbs before the fact, after 4 weeks and 8 weeks. Results : According to the conclusions, external-feedback weight-bearing training to prevent a fall was more effective intervention in experimental group than in control group. Conclusion : This study suggests that external-feedback weight-bearing training is a intervention to prevent the fall of hemiplegic patients with a stroke effectively.

• 항공우주기술
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• 제5권2호
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• pp.47-52
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• 2006

항공우주연구원 중형아음속풍동에서 사용 중인 외장형 풍동저울은 영국 Aerotech에서 제작한 제품으로, 1998년 설치되어 2004년까지 70여개의 시험에 활용되어 왔다. 7년여 동안 풍동저울을 운영하면서 발생된 문제점 해결과 정밀도 향상을 위해 2004년-2005년 외장형 풍동저울 개선 및 재보정을 수행하였다. 본 논문에는 1998년 Aerotech이 수행한 보정 결과, 2004년 간이보정장치를 사용하여 수행한 결과, 그리고 2005년 재교정 결과가 수록되어 있다.

• 한국전문물리치료학회지
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• 제15권2호
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• pp.11-19
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• 2008

Studies of attentional focus effects, have shown that the performer's attentional focus plays an important role in the performance and learning of motor tasks. We examined the influence of attentional focus on the performance of dual tasks (a postural task and a suprapostural task) and used electromyography (EMG) to examine whether the differences between external and internal focus were also manifest at the neuromuscular level. The subjects (n=40) stood on a balance board (postural task) and held a bar horizontally (suprapostural task). All of the subjects performed under different attentional focus conditions: external (balancer on balance board) or internal (feet) focus on the postural task, and external (balancer on bar) or internal (hand) focus on the suprapostural task. The mean displacement velocity of the bar and the percent reference voluntary contraction (%RVC) of the biceps brachii were reduced when the subjects adopted an external focus on the suprapostural task (p<.05). In addition, the mean displacement velocity of the balance board and %RVC of the tibialis anterior were reduced when the subjects adopted an external focus on the postural task (p<.05). When the subjects adopted an external focus on the suprapostural task, the mean displacement velocity of the balance board and %RVC of the tibialis anterior were also reduced (p<.05). When the subjects' attentional focus was on the postural task, there were no differences in the mean displacement and %RVC of the biceps brachii between attentional focuses. The performance of each task was enhanced when subjects focused on the respective task. The suprapostural task goals had a stronger influence on postural control than vice versa. These results reflect the propensity of the motor system to optimize control processes based on the environmental outcome, or movement effect, that the performer wants to achieve.

• The Journal of Korean Physical Therapy
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• 제15권3호
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• pp.173-188
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• 2003

The two groups each consisting of 28 people who had an adult hemiplegia due to a brain injury received two different methods of exercises to reduce the angle to which the affected lower limb rotates externally. The comparisons between the two groups were made for the changes of the angle in external rotations measured between pre and post test. The static balance index values taken during pre and post tests were also compared. In addition, the correlations of the angle to which the affected lower limb rotates externally with static balance index values were analyzed. The result were as follows: 1. A statistical analysis indicated that in group one having taken simple R.O.M exercises, the angle to which the affected lower limb rotates externally and the static balance index values were both significantly different between pre and post test (P<.01). 2. A statistical analysis indicated that in group two having taken a pattern movement, both the angle to which the affected lower limb rotates externally and static balance index values were significantly different between pre and post test (P<.01). 3. A significant difference between simple R.O.M exercises group and pattern movement exercises groupwas shown only for the angle to which affected limb rotates externally not for static balance index values (P<.01), 4. Pearson correlation coefficient for the angle to which the affected limb rotates externally with static balance index values was found to be significant only in pattern movement exercises group (P < .05).

• 국제물리치료학회지
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• 제2권1호
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• pp.260-266
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• 2011

The purpose of this study was to investigate the effects of meditation music with lumbar stabilization exercise on balance, concentration and muscle activation. Participants are divided into Group A and Group B. Group A listened to meditation music while doing 4 sets of lumbar stabilization exercise. Group B did not listen to meditation music while doing 4 sets of lumbar stabilization exercise. Surface EMG data was obtained rectus abdominis, external oblique, erector spinae, multifidus muscle during lumbar stabilization exercise. To examine the effect of before-after experiment for concentration and balance, paired t-test was adopted. Changes in EMG data of each muscles were analyzed by independence t-test. There were statistically significant increasing at concentration level and balance level in Group A. But significant difference was not shown in muscle activation. The clinical effect of the meditation music with lumbar stabilization exercise was investigated in this study with more excellent results in concentration and balance. In conclusion, these results suggest that meditation music and lumbar stabilization exercise may be useful in elderly people.

• 대한물리치료과학회지
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• 제29권1호
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• pp.64-72
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• 2022

Background: The purpose of this study is to investigate the effect of wall squat exercise according to the difference in the support surface on the thickness change of external oblique, internal oblique and transverse abdominalis of the trunk muscles and the change in distance of center of pressure when the eyes are opened and closed. Design: Randomized controlled trial. Methods: The subjects were 26 healthy adults, 18 males and 8 females. The composition of each group using the single-blind method was 13 people in the unstable side wall squat exercise group and 13 people in the stable side wall squat exercise group. Experimental measurements were divided into before, 3 weeks, and 6 weeks after the experiment, and changes in muscle thickness and balance were confirmed. Muscle thickness was measured using ultrasinic, and static balance change was measured using Bio-rescue. Results: There were significant differences in the thickness changes of external oblique, internal oblique and transverse abdominalis according to the wall squat exercise method by period and in the interaction between the period and the group (p<0.05). As a result of the post-hoc analysis, there was a significant difference in the change between the two groups in external oblique muscle after 6 weeks. And there was a significant difference in the distance of the pressure center between eyes open and closed eyes (p<0.05). Conclusion: In terms of instability, wall squat exercise was positive for changes in trunk muscle thickness. It suggests the possibility of using it for trunk muscle strengthening training in the future.

• The Journal of Korean Physical Therapy
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• 제24권5호
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• pp.300-305
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• 2012

Purpose: This study examined the muscle activity of the trunk muscles during weight shifting exercises on a stable and unstable surface. Methods: Ten healthy young subjects (4 males, 6 females) with no medical history of lower-extremity or lumbar spine disease were enrolled in this study. The muscle activity was recorded using surface electromyography (EMG) electrodes from the both sides of the external obliques and erector spinae muscles. Results: The EMG activities of the both rectus abdominalis, both external obliques and erector spinae muscles were significantly higher when the weight shifting exercise was performed on a firm surface than when a balance pad with a balance ball was used. In weight shifting exercises, the EMG activity of the contralateral external obliques and erector spinae muscles was significantly higher than that of the ipsilateral external obliques and erector spinae muscles under all three support surface conditions. Conclusion: Performing weight shifting exercise using an unstable surface is a useful method for facilitating the trunk-muscle strength and trunk stability.