• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.303-306
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• 2011

An experimental study has been conducted to investigate the effects of an ultrasonic standing-wave field to the behavior of methane/air premixed flame. Visualization technique utilizing the schlieren method was employed for the observation of premixed flame behavior. The shape of flame front and local flame velocity were measured according to the variation of reactants pressure and chamber opening/closing condition. The flame front was distorted and severely deformed to a lotus-type flame by the interaction of ultrasonic standing-wave and the reflection wave coming from an end wall of reactor.

• Journal of Korean Physical Therapy Science
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• v.6 no.1
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• pp.915-921
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• 1999

The purpose of this study was to determine the effect of testing posture and shoulder position on grip strength. The subjects were one hundred volunteers of Shinsung College (50 males and 50 females), ages from 20 to 27 years(mean age of 22.1 years). This study was carried out from september 7 to setember 10, 1998. The data were analyzed by mean and deviation, unpaired t-test, paired t-test, one way ANOVA and correlation. These results were obtained as follows; 1. Comparison on grip strength by left and right hand, there was a significant difference in standing and sitting position (p<0.05). 2. Comparison on grip strength between male and female, there was a significant difference in standing and sitting position (p<0.05). 3. One-way ANOVA on grip strength according to shoulder joint angle, there was a no significant difference in standing and sitting position (p>0.05). 4. Correlation on grip strength by sitting verus standing, there was a very significantly difference (p<0.01).

• Physical Therapy Korea
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• v.7 no.1
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• pp.46-54
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• 2000

The purpose of this study is to determine whether movement strategies affect functional forward reach distance in a standing position. Forty-seven healthy subjects were selected for this study: 23 men and 24 women, with an average age of 22.3. Functional forward reach distances were measured as hip strategy and squat strategy (included knee and ankle movement strategy) in a standing position, respectively. The mean values of functional forward reach distance in hip strategy, squat strategy were 33.57 cm, 29.48 cm, respectively. There was significantly difference in functional forward reach distance between hip strategy and squat strategy(p<.001). There was no difference of functional forward reach distance between male and female in hip strategy, but there was significant difference in other strategy(p<.05). These results suggest that movement strategies should be considered during functional forward reach test in standing. Further study is required to determine whether movement strategies affect functional reach distance in elderly and disabled groups.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.11
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• pp.958-962
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• 2002

This paper reports on the fabrication of free-standing microstructures by DRIE (deep reactive ion etching). SOI (Si-on-insulator) structures with buried cavities are fabricated by SDB (Si-wafer direct bonding) technology and electrochemical etch-stop. The cavity was formed the upper handling wafer by Si anisotropic etch technique. SDB process was performed to seal the formed cavity under vacuum condition at -760 mmHg. In the SDB process, captured air and moisture inside of the cavities were removed by making channels towards outside. After annealing (100$0^{\circ}C$, 60 min.), the SDB SOI structure with a accurate thickness and a good roughness was thinned by electrochemical etch-stop in TMAH solution. Finally, it was fabricated free-standing microstructures by DRIE. This result indicates that the fabrication technology of free-standing microstructures by combination SDB, electrochemical etch-stop and DRIE provides a powerful and versatile alternative process for high-performance bulk micromachining in MEMS fields.

• The Korean Journal of Ecology
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• v.6 no.2
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• pp.114-127
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• 1983

The production and productivity of $C_3 and C_4$ type plants in Korea was studcied In the areas, in which the summer temperature is above $30^{\circ}C,;C_3$ type plants showed“M” type productivity curves exhibiting two peaks in spring and autumn, and C4 type plants showd “Bell” type productivity curves which show one peak in summer(Figs. 1,2,3,4,5). From the result of researching the standing crop of $C_3 and C_4$type plants dcuring August and September in which the standing crop reaches the highest peak, the dominant plants in the natural grass vegetation were almost all of $C_4$ type plants, showing the high standing crop, while the standing crop of $C_3$ type plants shows its high peak in the humid areas, riversides and dams.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.20 no.2
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• pp.1-7
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• 2014

Purpose: The purpose of this study was to compare the effects of the balance training on the stable and unstable supporting surfaces for the subjects with functional ankle instability. Methods: Twenty-nine subjects with functional ankle instability were randomly assigned to the stable group (n=14) and the unstable group (n=15). Balance training was conducted twenty minutes a day on the stable surface for the stable group and on the airostep for the unstable group three times a week for four weeks. Balance training program was consisted of ten steps by eye opened or closed and two or one leg standing. X-speed for transverse balance and Y-speed for longitudinal balance were measured with eye opened and closed in affected leg standing position. Results: There were significant improvements of balance ability in eye opened (p<.01) and eye closed standing (p<.01) in stable group. Unstable group also showed significant improvements of balance ability in eye opened (p<.01) and eye closed standing (p<.01). There were no statistical differences in the magnitude of improvement between the groups (p<.05). Conclusions: Based on such results, it can be said that balance training on the stable surface is effective as much as training on the unstable surface for the subjects with functional ankle instability.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.19 no.2
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• pp.55-60
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• 2013

Background: The purpose of this study was to determine if there is a difference in activation of the rectus femoris, vastus medialis oblique, vastus lateralis, semitendinosus, and biceps femoris when performing normal free squat with standinding position and free squat with $30^{\circ}$ flexed hip joint. Methods: Electromyograph surface electrodes were placed on the rectus femoris, vastus medialis oblique, vastus lateralis, semitendinosus, and biceps femoris of 19 healthy college students. The participants performed standing bilateral squats and standing bilateral squats with $30^{\circ}$ flexed hip joint with EMG measures taken upon initiation of muscle activity as confirmed by an electronic goniometer. Participants completed one trial with the EMG time measurements on each type. Results: There was a significant difference between normal squats(standing squats) and normal squats with $30^{\circ}$ flexed hip joint. The normal squat exercise was statistically higer than normal squat exercise with $30^{\circ}$ flexed trunk except for semitendinosus and biceps femoris that shown slightly high. Conclusions: As a result of this study, there were increases of muscle activity in both ways. In particular, it may be more beneficial for knee joint stabilization to perform normal squat exercise with standing position relatively.

• Physical Therapy Korea
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• v.21 no.2
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• pp.28-36
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• 2014

The purpose of this study was to evaluate the changes in the electromyographic (EMG) activity of the trunk and the lower limb muscles during quiet standing on an unstable surface while wearing low-heeled shoes (3 cm), high-heeled shoes (7 cm) and without footwear (0 cm) in 20 young healthy women. The subjects stood on an unstable surface for 30 seconds. We examined the differences in the EMG data of the erector spinae, rectus abdominis, biceps femoris, rectus femoris, tibialis anterior, and the gastrocnemius medialis muscle. A one-way repeated analysis of variance was used to compare the effects of shoe heel height on the EMG activity with the level of significance set at ${\alpha}=.05$. The EMG activity of the erector spinae and the rectus femoris were significantly increased (p<.05) in the subjects who wore elevated heel height, while the tibialis anterior and the gastrocnemius medialis were significantly decreased (p<.05). However, the rectus abdominis and the biceps femoris exhibited no significant difference among the three conditions. The above results indicate that wearing high-heeled shoes may change the postural strategy. The findings of this study suggest that excessive heel height could contribute to an increased fall risk during quiet standing.

• ALGAE
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• v.18 no.3
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• pp.207-215
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• 2003

Dynamics of phytoplankton communities were investigated at five stations in Youngsan River from December 1995 to November 1996. Phytoplankton were identified to the total of 466 taxa, which were composed of 136 genera, 438 species, 27 varieties and 1 forma. The standing crops ranged 1,163-50,765 cells ${\cdot}ml^{-1}$ during the investigation periods. The variation of classes was in order to Chrysophyceae - Bascillariophyceae - Chlorophyceae at St. 1 and was only Bacillariophyceae at the other stations. The dominant species were 12 taxa including Aulacoseira ambigua, A. garnulata, Cyclotella meneghiniana, C. pseudostelligera, Chlorella vulgaris, Dinobryon sertularia, Flagilaria elliptica, Monoraphidium contortum, Micractinium pusillum, Nitzschia palea, Scenedesmus grahneisii and Stephanodiscus hantzschii f. tenuis. The standing crops of dominant species ranged from 10.6% to 94.7%. The genus Dinobryon in Chrysophyceae was dominant species at St. 1 in December 1995, but not recorded in the other months. The dominant species were composed with the planktonic diatoms from winter to spring and were the tychoplanktonic and the benthic species at St. 2-5 from summer to fall. The relationships between total standing crops and water temperature, pH, $NH_4$, $NO_2$, $NO_3$ and $PO_4$ showed low positive or negative coefficients. Stephanodiscus hantzschii f. tenuis had low positive or negative coefficients with water temperature, $NH_4$, $NO_2$, $NO_3$ and $PO_4$. The fluctuations of standing crops in the Youngsan river phytoplankton community were not caused by a single factor but controlled by the complex factors with interaction between phytoplankton community and envirowmental factors.

• The Journal of Korean Physical Therapy
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• v.11 no.2
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• pp.111-114
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• 1999

Some hemiplegic patients show a particular posture that pushing away from the nonaffected side of the body. A few study has been conducted of any aspect of this syndrome. But despite the lack of a scientific basis, this term is widely used in the physical therapy of hemiplegic patients. The purposes of this study was to investigate whether pusher syndrome has an adverse impact on functional outcome. Included were all acute stroke patients admitted in a months period a hospital in Seoul. The presence of pusher syndrome was assessed by a Bobath trained physical therapist. The ability of transfer was assessed by the Functional Independence Measure(FIM), Activities of daily living by the Modified Barthel Index(MBI), and standing balance by Bohannon's Standing Balance Scale(BSBS) on admission, weekly during the hospital stay, and at discharge. Pusher syndrome was found in $52.4\%$ of the left side and $50.0\%$ of the right aide hemiplegic patients. Significant differences were found in the score of transfer, ADL and standing balance between patients with and without pusher syndrome.