• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.136-141
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• 2010

This study describes effects of width contraction in vaneless diffuser on the performance of centrifugal compressors using commercial CFD code. Numerical analysis for three different diffusers such as Parallel, half contraction, and full contraction was performed. The results show that the performance of the centrifugal compressor is improved through the use of the diffusers with width parallel in high flow rate. The width contraction of diffusers is influenced static pressure rises. Comparison with the experimental data shows agreement.

• Journal of Veterinary Clinics
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• v.20 no.3
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• pp.341-344
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• 2003

This study was carried out to investigate the effects of the wound contraction of chitosan, aloe vera, fucidin natrium, and premycin ointment on defected wound from full-thickness skin defects(1 cm $\times$ 1 cm). Twelve dogs were designed in 5 different positions on the dorsal thoracolumbar. We examined the effects of wound contraction every four other day 16 for days. Percentage of wound contraction based on epitherial overall area of defected wound which calculated by image analyzer and computer. Four to 8 days after wound contraction in wound defected dogs, the epithelial overall rate were the most high presented by 48.1 % in the chitosan group and were the lowest by 26.8% in the premycin group. In 16 days, chitosan group were the most heigh presented by 94.4% and premycin group were the lowest by 76.5% compare to saline group of 85.9%. Thus, we conclude that the chitosan is a possible role for improvement of wound contraction by wound defected dogs.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.2 no.2
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• pp.1-12
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• 2004

The purpose of this study was to determine the effect of muscle fatigue by neuromuscular electrical stimulation(NMES). Using Biodex System 3PRO(Biodex Medical Systems Inc, USA), experiment was conducted as to the normal group(I) composed of fifteen adults and the patient group(II) composed of fifteen patients with spastic hemiplegia. As to each group, maximal tolerated intensity(MTI) and maximal tolerated isometric contraction(MTIC) in electric currents yielded by low rate(20 pps) and high rate(100 pps) neuromuscular electrical stimulation and the aspects of decrease and restoration of the isometric contraction were examined, and their strength decrement index(SDI) and strength recovery index(SRI) were also calculated. 1. As for MTI in NMES, the MTI of the group II was higher than that of the group I in both low rate and high rate NMES. In comparison within group, MTI of group II was significantly higher in high rate NMES rather than in low rate NMES(p<0.05). 2. In comparison of MTIC between groups, the group I showed higher in both low rate and high rate NMES. In comparison within group, MTIC of group II was significantly higher in high rate NMES rather than in low rate NMES(p<0.01). 3. As for SDI, both groups showed highest SDI in high rate NMES, but no significant differences could be observed. 4. As for SRI, both groups showed significantly low SRI in low rate NMES(p<0.01, p<0.05), and comparison between groups showed no significant differences could be observed. These result lead us to the conclusion that muscle fatigue was influenced by frequency, high rate NMES was lower at SDI and higher at SRI on compare to low rate NMES, therefor, a further studies concerning electrical stimulation should consider differences each frequency in response to treatment.

• Physical Therapy Korea
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• v.11 no.3
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• pp.85-90
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• 2004

The purpose of this study was to find the difference in muscle firing rate between each muscle according to the knee angle with the quadriceps femoris which is a representative action muscle of the lower extremity. Seven normal healthy subjects were recruited. The median frequency (MDF) of muscle contraction was recorded from vastus lateralis, vastus medialis, and rectus femoris muscles using the surface EMG, in 5 seconds, during maximal isometric knee extension. The data were analyzed by the two-way repeated ANOVA. The results of the study were as follows: 1) median frequency of muscle contraction was significantly higher at the vastus lateralis, vastus medialis, and rectus femoris in descending order. 2) median frequency of muscle contraction was significantly higher at the $30^{\circ}$, $60^{\circ}$, and $90^{\circ}$ in descending order. Consequently, muscle recruitment at the knee decreases the EMG activity of the lengthened muscle. This study suggests that the change in EMG activity at different muscle lengths resulted in affecting the muscle firing rate during the knee extension.

• Journal of the Korean Society of Clothing and Textiles
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• v.20 no.2
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• pp.257-269
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• 1996

The puropose of this study was to investigate the movement-fitness according to the surface changing of lower limb The experimental items were divided into the lower limb movements (5) and body-shapes (7). This study was done by the expansion and contraction rate consideration of length, girth Also, the lower half of body shape-change on the movements and body-shapes by flat shell was done simultaneously. The summarized findings resulted from experiments and investigation are suggested as follows; First, when commpared the expansion and contraction rate of the length and girth items, the expansion rate of the back crotch length (14~20%), hip girth (10~ 21%) and knee girth (6.2~18.5%) in rabbit leap movement was the most notable among all variables considered in this experimentation. On the others hand, the front croth length (-22~-52%) contracted remarkably. And big-thigh type was the most notable on the body-shape comparision. Second, in comparision of the expansion and contraction rate of the area on the blocks, the expansion of the hip (50~200%) and knee (51~74%) block was the most remarkable. Especially, in the sit on knees movement of the hip-down type expanded 209.4%. Third, in comparision of the lower half of body shape-change, on the movements and body- shapes by the flat shell, under the influence of knee-joint and hip-joint the shape-changs of the hip and knee block was the most notable. But the shape-change of the waist, abdomen, calf, and ankle was feeble.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.57-59
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• 2004

This paper reports the observation of the interferometric synthetic aperture radar (InSAR) phase anomaly on a newly reclaimed mudflat, Hwaong, in west coast of Korea, detected by a series of Radarsat-l SAR data obtained mostly during 2003. The observed phase anomaly could be from subsidence of mud land caused by volumetric contraction of mud in dry season. This process must have been initiated from March 2002 when tidal water supply to this region was permanently blocked by the newly constructed embankment. The maximum subsidence rate measured from InSAR signal is about 3 cm per month. The local heterogeneity of the subsidence rate over the reclaimed mudflat may indicate various mud composition, surface-subsurface hydrological processes, or subsurface information of the mud and basement rock structure. In-situ measurement must follow to support this observation from space.

• Journal of the Korea Society of Computer and Information
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• v.22 no.5
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• pp.65-72
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• 2017

Premature Ventricular Contraction(PVC) arrhythmia is most common abnormal-heart rhythm that may increase mortal risk of a cardiac patient. Thus, it is very important issue to identify the specular portraits of PVC pattern especially from the patient. In this paper, we propose a new method to extract the characteristics of PVC pattern by applying K-means machine learning algorithm on Heart Rate Variability depicted in Poinecare plot. For the quantitative analysis to distinguish the trend of cluster patterns between normal sinus rhythm and PVC beat, the Euclidean distance measure was sought between the clusters. Experimental simulations on MIT-BIH arrhythmia database draw the fact that the distance measure on the cluster is valid for differentiating the pattern-traits of PVC beats. Therefore, we proposed a method that can offer the simple remedy to identify the attributes of PVC beats in terms of K-means clusters especially in the long-period Electrocardiogram(ECG).

• Korean Journal of Human Ecology
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• v.18 no.3
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• pp.729-740
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• 2009

This study is to research on the rate of expansion or contraction according to movement of the lower body of the man their twenties using Rapid Form software. And aim of this study is to get information of ease allowance in developing slacks pattern using 3D body surface scan data through comparison with existing slacks patterns. Considering on the contraction and expansion according to movement, it need to set the more ease allowance in hip circumference than waist circumference, and the more ease allowance in back hip width than front hip width in slacks. In crotch length, the length of front crotch is revealed contraction but the length of back crotch is revealed expansion. It is desirable lowering front waist line and raising back waist line to possess ease allowance in back crotch area. The length of side seam is revealed a little expansion but the length of inseam is showed a great expansion. To develop slacks pattern of scientific approach using 3D body surface scan data, it need to analysis the rate of expansion and contraction of the lower body based on the movement, shear deformation, slip in fabrics and skin, or in fabrics and fabrics, and slip down from waist line.

• The Korean Journal of Physiology
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• v.23 no.1
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• pp.99-108
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• 1989

The effects of prostaglandin $(PGF_{2{\alpha}})$ on the contractility of vascular smooth muscle were investigated in the helical strip of the rabbit aorta. The aortic strip was immersed in the phosphate-buffered Tyrode's solution which was equilibrated with 100% $O_{2}$ at $35^{\circ}C$ and its isometric tension was measured. The contraction was induced by $(PGF_{2{\alpha}})$, norepinephrine (NE), or potassium (40 mM) in the nomal Tyrode's solution (1 mM, $Ca^{2+}$) or $Ca^{2+}-free$ Tyrode's solution. Effects of verapamil and phentolamine on the contraction were also observed. The aortic strip began to contract at the concentration of $5\;{\mu}g%$ and reached the maximal contraction at the concentration of $150\;{\mu}g%$ $(PGF_{2{\alpha}})$. The maximal contraction was corresponded respectively to $52.2{\pm}3.0%$ and $81.5{\pm}3.5%$ of maximal contraction by NE $(1{\times}10^{-5}M)$ and 40 mM $K^{+}$. And the maximal contractions by $(PGF_{2{\alpha}})$ or NE were induced at the concentration of about 1 mM $Ca^{2+}$. $(PGF_{2{\alpha}})$ induced the contraction of aortic strip even after induction of contraction by 40 mM $K^{+}$ and the contraction by $(PGF_{2{\alpha}})$ was not blocked by the ${\alpha}-receptor$ blocker, phentolamine. And the contraction by the $(PGF_{2{\alpha}})$ was inhibited partially by a verapamil at the concentration of $1{\times}10^{-5}M$ and the contraction began to increase at the concentration of $1{\times}10^{-4}M$ verapamil. Whereas the contraction by NE was completely blocked by verapamil. Though both the $(PGF_{2{\alpha}})$ and NE induced the contraction in the $Ca^{2+}-free$ Tyrode's solution, the peak tension was not maintained. But the rate of tension decline was lower in the contraction by $(PGF_{2{\alpha}})$ than in that by NE. The verapamil did not inhibit the contraction by $(PGF_{2{\alpha}})$ in the $Ca^{2+}-free$ Tyrode's solution and increased the contraction at the concentration of above $1{\times}10^{-4}M$. The NE-induced contraction in the $Ca^{2+}-free$ Tyrode's solution was inhibited completely by a verapamil. From the above results it is suggested that the contraction induced by $(PGF_{2{\alpha}})$ results from the promotion of the both $Ca^{2+}$ influx and the intracellular $Ca^{2+}$ release by different way from NE.

• Archives of Plastic Surgery
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• v.38 no.5
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• pp.576-584
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• 2011

Purpose: The shape and location, the amount of the wound and the characteristics of the remaining tissues are known to influence wound contraction. The previous studies using small animals have not been an appropriate model because the wound healing mechanisms and skin structures are different from those of the human. The purpose of this study is to evaluate wound contraction according to the shape and location of the wound using a $Micropig^{(R)}$. Methods: Four $Micropigs^{(R)}$ (Medikinetics, Pyeongtaek, Korea) that were 10 months of age weighed 25 kg were used. Full thickness skin defects were made by clearing all the tissues above the fascial layer in the shape of square, a regular triangle and a circle of 9 $cm^2$ each on the back around the spine. Eight wounds were created on the back of each pig, 50 mm apart from each other. The randomly chosen wound shapes included 11 squares, 11 regular triangles, and 10 circles. Wound dressing was done every other day with polyurethane foam. The wound size was measured using a Visitrak $Digital^{(R)}$ (Smith & Nephew, Hull, UK) on every other day after surgery from day 2 to day 28. A biopsy was performed on day 3, and 1, 2, 3 and 4 weeks to investigate the degree of acute and chronic inflammation, the number of microvesssel and myofibroblast density using H & E stain and immunohistochemistry. The wound contraction rate was calculated to figure out the differences among each of the shapes and the locations. Results: The ultimate shape of the circle wound was oval, and that of the regular triangle and square were stellate. The maximum contraction rate was obtained on 8 to 10 days for all the shapes, which corresponds with the immunohistochemical finding that myofibroblast increases in the earlier 2 weeks whereas it decreases in the later 2 weeks. Epithelialization was seen in the wound margin on day 7 and afterwards. The final wound contraction rates were highest for the regular triangle shapes; however, there were no statistically significant differences. The wound contraction rates by locations showed statistically significant differences. The wound in the cephalic area presented more contractions than that of the wounds in the caudal area. Conclusion: The location of a wound is more important factor than the wound shape in wound contraction.