• Physical Therapy Korea
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• v.13 no.3
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• pp.1-9
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• 2006

The purpose of this study was to assess the influence of spine orthosis and sit-to-stand motor strategies on ground reaction force (GRF) and lower extremity muscle activity. Twenty healthy adult men participated, and subjects randomly performed sit-to-stand motions in three different conditions: Momentum-transfer strategy (MTS); MTS with spine orthosis; and zero-momentum strategy (ZMS) with spine orthosis. GRF data, onset time, and muscle activity were determined and compared using force plate and electromyography. Data were statistically analyzed by the SPSS version 13.0. One-way repeated analysis of variance (ANOVA) was used to determine the statistical significance, and least significant difference was used as a post hoc test. The level of significance was .05. The results of this study were as follows: 1. Peak GRF and relative time to peak GRF were not significantly different in the three different conditions (p>.05). 2. Onset time of four muscles, tibialis anterior, gastrocnemius, biceps femoris and rectus femoris, in the three different conditions were significantly different (p<.05). 3. The tibialis anterior and rectus femoris muscle activity before hip-off and tibialis anterior, gastrocnemius, and rectus fermoris muscle activity after hip-off were significantly different in the three different conditions (p<.05).

• Korean Journal of Veterinary Research
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• v.28 no.1
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• pp.67-73
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• 1988

This study was conducted to isolate etiological agents from the 103 scouring piglets in Gyeongnam area and also carried out antimicrobial drug susceptibility test and epidemiogical served. The incidence of scouring piglet was most prevalent as 81.6% in the age of 2 to 4 weeks after birth, while the rate was less than 10% in the age of 5 to 6 weeks and under 1 week after birch. When compared the isolation frequency of the each etiological agent, enteropathogenic E. coli was most prevalent as 46.6%, thermophilic Campylobacter 26.2% and Salmonellae was 8.7% in order. In the OK serotyping for 117 isolates of enteropathogenic E. coli, type 0141 : K85 (20.5%), 0157:K88ac(14.5%), 0138:K81 and 0149:K91 (13.3%) were encountered most frequently. In the biotyping for 27 isolates of thermophilic Campylobacter, most strains of C. jejuni were belong to type I (50.0%) and II (25.0%), and most strains of C. coli were belong to biotype I (78.9%). In the serotyping for 9 strains of Salmonellae, 3 strains were grouped as D, 2 strains as C. and each 1 strain was group B and E. The other 2 strains were untypable. The 117 isolates of enteropathogenic E. coli were resistant more than 90% to erythromycin, penicillin, tetracycline and streptomycin, wherease about 90% of the isolates were sensitive to kanamycin and gentamicin. In the case of Salmonellae, all of the isolates were resistant to penicillin, but about 89% of the isolates were sensitive to gentamicin and colistin. All of C. jejuni and C. coli isolates were resistant to cephalothin, but more than 89% of C.jejuni and C. coli were sensitive to kanamycin and gentamicin.

• The KIPS Transactions:PartB
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• v.16B no.4
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• pp.319-326
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• 2009

PSO(Particle Swarm Optimization) is an optimization algorithm in which simple particles search an optimal solution using shared information acquired through their own experiences. PSO applications are so numerous and diverse. Lots of researches have been made mainly on the parameter settings, topology, particle's movement in order to achieve fast convergence to proper regions of search space for optimization. In standard PSO, since each particle uses only information of its and best neighbor, swarm does not explore diverse regions and intended to premature to local optima. In this paper, we propose a new particle's movement strategy in order to explore diverse regions of search space. The strategy is that each particle moves according to relative weights of several better neighbors. The strategy of exploring diverse regions is effective and produces less local optimizations and accelerating of the optimization speed and higher success rates than standard PSO. Also, in order to raise success rates, we propose a strategy for checking whether swarm falls into local optimum. The new PSO algorithm with these two strategies shows the improvement in the search speed and success rate in the test of benchmark functions.

• Physical Therapy Korea
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• v.13 no.2
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• pp.70-76
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• 2006

The purpose of this study was to investigate the effects of hip extension velocity (7.5 degree/second, 30 degree/second) on the relative onset time of the gluteus maximus in relation to the hamstring during hip extension in prone position. Thirteen healthy male subjects (mean age=22.6 years [SD=1.8], mean weight=73.4 kg [SD=10.3], mean height=176.1 cm [SD=6.3]) voluntarily participated in this study. Electromyographic data was collected on the gluteus maximus and hamstring to determine onset time. Statistical analyses were performed with the paired t-test. The results showed that the onset time of the hamstring was significantly faster than that of the gluteus maximus in both fast and slow hip extension velocity. The gluteus maximus began contraction .079 seconds later following the contraction of the hamstring. The onset time of the hamstring was significantly faster in fast hip extension velocity compared with slow hip extension velocity. In conclusion, it was determined that the onset time of the gluteus maximus was faster with fast hip extension velocity compared with slow hip extension velocity. There was a statistically significant difference between the onset times of the gluteus maximus and hamstring in relation to the two velocities (p<.05). Further study is needed to examine whether the velocity of hip extension can influence the onset time in a similar fashion in patients with low back pain.

• Physical Therapy Korea
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• v.17 no.1
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• pp.17-25
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• 2010

The aim of this study was to investigate the effect of supporting surface instability to trunk and lower extremity muscle activities during bridging exercise combined with core-stabilization exercise. Thirty young healthy adults (15 males and 15 females) voluntarily participated in this study. Each subject was asked to perform bridging exercise combined with core-stabilization exercise on three different supporting surfaces (stable ground surface, the wooden balancing board, and the air cushion). The muscle activities were measured using surface electromyography (EMG) during performing exercise. To test statistical significance, one-way ANOVA with repeated measures was used with the significance level of .05. The findings of this study are summarized as follows. (1) There were significant differences in muscle activities on internal oblique, external oblique, gluteus medius, semitendinosus, biceps femoris, medial gastrocnemius and lateral gastrocnemius during exercise (p<.05). (2) The biceps femoris and lateral gastrocnemius showed significantly higher muscle activity on the wooden balancing board rather than on the ground, and semitendinosus, biceps femoris, medial gastrocnemius and lateral gastrocnemius showed significantly higher muscle activity on the air cushion rather than on the ground (p<.05). Therefore, it is concluded that muscle activities in the trunk and the lower limbs during bridging exercise combined with core-stabilization exercise was affected with instability of supporting surface. Further researches are needed to investigate the long term effect of bridging exercise on muscle activity with patient group.

• Fire Science and Engineering
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• v.29 no.3
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• pp.21-30
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• 2015

In this study, we try to suggest measures to reduce leakage at a joint between CPVC piping for a sprinkler system and a pipe expansion through reviews of domestic and foreign standards and related tests. The quality of the waterproof rubber packing material between a valve socket and pipe expansion nut was examined. In the leak test, the valve socket material over the expansion part of the metal pipe nut was found to use a metal part or a schlorinated polyvinyl chloride pipe nut part. In addition, the KS B 0221 standard for parallel pipe threads with threaded and thread inspection criteria and inspection standards in order to ensure an acceptable quality of valve socket, there is a need to amend the regulations to comply with the KS B 5223 (screw thread limit gauges parallel pipe threads). We do not have detailed standards for expansion piping nuts for waterproof rubber ring material, so we need to amend the relevant criteria for EPDM material to be used with excellent waterproofing, for which both NBR and EPDM are currently used.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.1 s.190
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• pp.110-117
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• 2007

This study investigated changes of mechanical characteristics of the trabecular and cortical bone in the lumbar vertebrae of the ovariectomised (OVX) rat. In previous researches, there were many studies for morphology of osteoporotic bones based on Micro-Computed Tomography (Micro-CT). However, there were few studies for detecting and tracking changes of mechanical characteristics of the trabecular and cortical bone in the lumbar vertebrae of the OVX rat. For this study, the 4th lumbar of the OVX rat (female Sprague-Dawley) was utilized as a specimen. An OVX rat was scanned at week 0 (just before surgery), at week 4, and week 8 after surgery. Micro-finite element (${\mu}-FE$) analysis was used to investigate mechanical characteristics of the trabecular and cortical bone in the lumbar vertebrae for an OVX rat. When the OVX rat (at week 8) was compared with the OVX rat (at week 0), the structural modulus of cortical and trabecualr bone was decreased by 52% and 99%, respectively. This study showed the change of mechanical characteristics of cortical bone as well as trabecular bone of an OVX rat. Detecting and tracking changes of mechanical characteristics could greatly contribute to an experiment test for the trabecular and cortical bone in the lumbar vertebrae of an OVX rat by using In-vivo Micro-CT.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.4
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• pp.1-9
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• 2017

PURPOSE: This study investigated the effect that an elastic therapeutic taping treatment given to patients with chronic ankle instability had on the vertical ground reaction force, center of pressure, and range of motion in the ankle, knee and hip joints, during a Cross-cutting movement from landing. METHODS: This study analyzed 12 able-bodied adults and 12 patients with chronic ankle instability classified by using the Cumberland tool in the motion analysis laboratory, Hanseo University. The experiment was conducted under two conditions elastic taping and no treatment. In order to analyze the difference between the groups. An independent t-test was performed at p>.01. RESULTS: Plying an elastic therapeutic taping to the patients with chronic ankle instability significantly decreased the range of joint motion in the inversion of the ankle joint, the flexion of the knee joint, and the flexion and internal rotation of the hip joint during a cross-cutting movement from landing in comparison with the able-bodied adults p<.01. This restriction in the range of motion decreased the center-of-pressure trajectory length of patients with chronic ankle instability p>.01. CONCLUSION: An elastic therapeutic taping treatment given to patients with chronic ankle instability causes ankle stability to increase during a cross-cutting movement from landing.

• Polymer(Korea)
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• v.38 no.4
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• pp.491-495
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• 2014

Pressure sensitive adhesive (PSA) based on 2-ethylhexyl acrylate (2-EHA)/acrylic acid (AA) copolymer was synthesized using different photoinitiators. Results showed that PSA with Irgacure$^{(R)}$651 (benzyldimethylketal) and Irgacure$^{(R)}$184(1-hydroxy-cyclohexylphenyl ketone) proved to be good for adhesion properties. This may be attributed to strong absorption near 350 nm wavelength and also high solubility in monomer mixtures. The addition of Irgacure$^{(R)}$819, bisacylphosphine oxides as a photoinitiator caused cohesive failure with high loading in a peel test owing to the additional radical formation. It is assumed that the insoluble photoinitiator reacts with oxygene, which may act as a hydrogen donor.

• Journal of the Korean Wood Science and Technology
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• v.35 no.5
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• pp.58-66
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• 2007

The objective of this research was to develop environment-friendly adhesives for face fancy veneer bonding of engineered flooring. Urea-formaldehyde (UF)-tannin and melamine-formaldehyde (MF)/PVAc hybrid resin were used to replace UF resin in the formaldehyde-based resin system in order to reduce formaldehyde and volatile organic compound (VOC) emissions from the adhesives used between plywoods and fancy veneers. Wattle tannin powder (5 wt%) was added to UF resin and PVAc (30 wt%) to MF resin. These adhesive systems showed better bonding than commercial UF resin with a similar level of wood penetration. The initial adhesion strength was sufficient to be maintained within the optimum initial tack range. The standard formaldehyde emission test (desiccator method) and VOC analyzer were used to determine the formaldehyde and VOC emissions from engineered flooring bonded with commercial UF resin, UF-tannin and MF/PVAc hybrid resin. By desiccator method, the formaldehyde emission level of UF resin showed the highest but was reduced by replacing with UF-tannin and MF/PVAc hybrid resin. MF/PVAc hybrid satisfied the $E_1$ grade (below $1.5mg/{\ell}$). VOC emission results by VOC analyzer were similar with the formaldehyde emission results. TVOC emission was in the following order: UF > UF-tannin > MF/PVAc hybrid resin.