• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.1
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• pp.80-91
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• 2003

Mutans streptococci, especially S. mutans and S. sobrinus strongly implicated in pathogenesis of dental caries, the major cause of tooth loss in children. Use of an antibacterial agent controlling dental caries has been rationalized. The present study was performed to observe the antibacterial effect of inorganic polyphosphates (polyP) on S. mutans and S. sobrinus. S. mutans GS5 and S. sobrinus 6715 were grown in brain-heart infusion broth with or without polyP. Minimal inhibitory concentration (MIC) of polyP for S. mutans GS5 was determined to be 0.08% and that for S. sobrius 6715 was 0.17%. PolyP 15 added to the growing culture of S. mutans GS5 and S. sobrinus 6715 at their exponential phase was as effective in inhibiting the growth of S. mutans GS5 and S. sobrinus 6715 as polyP added at the very beginning of the culture. More than 85% of the cells lost their viability determined by viable cell count when polyP 15 was added to the culture of growing S. mutans GS5 at MIC, suggesting that polyP 15 has bacterial effect on the bacterium. And more than 99.9% of the cells lost their viability determined by viable cell count when polyP 15 was added to the culture of growing S. sobrinus 6715 at MIC, suggesting that polyP 15 has bacterial effect on the bacterium. Intracellular nucleotide release from S. mutans CS5 and S. sobrinus 6715 was increased in the presence of polyP 15 for 5h but was not really reversed by the addition of divalent cations like $Ca^{++}\;and\;Mg^{++}$. The majority of the cells appeared to be atypical in their shape, demonstrating accumulation of highly electron-dense granules and ghost cells. The overall results suggest that polyP have a strong bactericidal activity against S. mutans and S. sobrinus in which lysis in relation to chelation may not play the major role but unknown mechanism that possibly affects the viability of the bacterium may be involved. PolyP may be used as an agent for prevention of dental caries.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.289-289
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• 2017

The climate change impact has facilitated double cropping system on maize production in Korea. The objectives of this study were to investigate the chemical composition changes according to the sowing dates on double cropping in 8 dent type, 2 intermediate type, and 4 semiflint type of Korean maize (Zea mays L.) hybrids and evaluate its antioxidant characteristics. Fourteen maize hybrids were sown on April 5 and July 5 of 2015. The average crude protein contents in dent and semiflint type maize sown on April 5 were higher than those sown on July 5 (p<0.05). There was no significant difference in average of total amino acid contents in all types of maize according to the sowing dates. Major amino acid in maize hybrids were glutamic acid followed by proline, alanine, and aspartic acid, which has no significant difference according to the sowing dates. The average crude fat contents in semiflint and intermediate type maize sown on April 5 were higher than those sown on July 5 (p<0.05). The average composition of saturated fatty acid in dent type maize sown on April 5 was higher than those sown on July 5. However, the average unsaturated fatty acid composition showed the opposite result (p<0.05). Fatty acids were mainly composed of linoleic acid (C18:2) and oleic acid (C18:1) in maize hybrids. The average oleic acid percentage of dent and semiflint type maize sown on April 5 were higher than those sown on July 5, while the average linoleic acid was lower. The average amylose content of all types of maize sown on April 5 was higher than those sown on July 5. On the other hands, the average carotenoid contents had the opposite result (p<0.05). There were no significant differences in total average of polyphenol contents and DPPH and ABTS radical scavenging activities in all types of maize based on the sowing date. Total polyphenol contents had positive correlation with DPPH (r=0.33, p<0.01) and ABTS (r=0.50, p<0.0001) radical scavenging activities. In conclusion, the kernel composition affects maize quality. These data are useful for maize breeding program and cultivation and food processing industry.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.57-58
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• 2008

• Communications of the Korean Mathematical Society
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• v.14 no.3
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• pp.597-609
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• 1999

In this article we prove a central limit theorem for strictly stationary weakly dependent random fields with some interlaced mix-ing conditions. Mixing coefficients are not assumed. The result it basically the same to Peligrad([4]), which is CLT weakly depen-dent arrays of random variables. The proof is quite similar to the of Peligrad.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.36-37
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• 2015

Recently, there has been a rapid increase in demand for lightweight walls for their use as interior partitions, as types of structure have gradually changed from shear wall structures to column structures or flat plate column wall systems. The lack of resisting force in lightweight walls is found by measuring the depth of dents in impact resistance tests, but it is not a direct factor of impact resistance. However, in the user's position, dents of over a certain size are clearly a factor that visually reminds the need for repair. In this study, we reviewed relative methods of assessment of the need for repair based on the visual means of determination (sensory test) on the dents on lightweight walls. Dents were found to stand out starting from depths of about 4mm, and the depth of roughly 5mm was found to be the criterion for determining the necessity of repair for men, while it was 4mm for women.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.279-282
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• 2011

Projectile can be damaged during the storage and handling. Maximum range calculation of the ammunition was performed on the assumption that each projectiles have 1.5mm/3.3mm axisymetric dent on the surface. Drag coefficient for trajectory calculation was delivered from CFD using commercial software FLUENT. In the result of CFD, damaged projectiles those have 1.5mm/3.3mm axisymetric dent have similar drag coefficient compare with normal projectile in the region of subsonic. But, in supersonic region, drag coefficient was increased 3%, 9% each in average. In the result of trajectory calculation, Maximum rage was decreased 1%, 3% each.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.5 no.2
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• pp.20-26
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• 2009

The dominant incidents category for onshore and offshore natural gas transmission pipelines in the world is associated with outside forces. Incidents in the outside forces category embrace acts of nature, which typically cause widespread structural damage, as well as act of man, whose effects tend to cause dents and/or gouges localized at point of contact that are referred to as mechanical damage. Therefore, these damage types must be better addressed to avoid unnecessary and costly repairs and the possibility of catastrophic events. First of all, the characterizing features of mechanical damage in gas pipelines were evaluated by using of excavator or boring machine. There is no reliable method for evaluating the safe operating pressure of pipeline affected by mechanical damage. It is especially important to evaluate the remaining strength of damaged pipelines due to outside force. Therefore, the full scale burst tests were conducted to evaluate the remaining strength of pipe with mechanical damage that combines a dent and a gouge. This paper is supposed to provide information that will assist in developing a criterion to assess serviceability in pipelines with mechanical damage.

• Journal of Acupuncture Research
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• v.18 no.1
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• pp.50-60
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• 2001

In order to review the studies related to the facial pain by acupuncture, we have referred to a PubMed site by using MeSH searching word of "facial pain and acupuncture". 12 journals with 20 papers were reported on the facial pain and acupuncture. Among them, 4 papers were appeared in Am J Chin Med, 3 in Acupunct Electrother Res, 2 in Br. Dent J, J Orofac Pain and Swed Dent J respectively, and 1 in 7 journals respectively. According to the classification of the patterns, 15 papers were done by clinical studies, 2 by review and meta-analysis respectively, and 1 by experimental study. TMD was the most disease that related to facial pain and CMD, neurogenic facial pain (trigeminal neuralgia, postherpetic pain), dental pain and MPS were also appeared. Most of the studies didn't mention the acupuncture points, L14 Habkok in 4 papers and ST36 Chogsamni in a paper were only mentioned. Various modalities were applied in the trials such as classical acupuncture, electroacupuncture, TENS, SSP and auricular acupuncture. By the above results, we concluded that various acupuncture techniques are used with effectiveness on the facial pain. It would be needed further research on the acupuncture point specific and therapeutic techniques as well.

• Journal of Power System Engineering
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• v.11 no.3
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• pp.53-58
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• 2007

The ruptured blade which is rotating at high speed can damage severely the all stage compressor blades and the turbine components. If the shattered blades flow downstream inside the turbine parts, then the turbine blades and vanes can be damaged. The small parts of shattered blades which are flowed into the turbine parts pass through without any damages in the leading edge of the first stage stationary blades. Then they bump against the convex side of the leading edge of the first stage moving blades and the trailing edge of the first stage stationary blades repeatedly. The debris of shattered blades may plug the cooling holes in the turbine blades and vanes. The dent damage and the coating delamination could be also occurred by the debris of shattered blades flowed downstream inside the combustion liner and the transition piece. This paper analyzes the influence on the turbine components and the damage mechanism and characteristics in case of the damaged blade of the multiple-stage axial flow compressor.

• Journal of the Korean Society of Safety
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• v.20 no.4 s.72
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• pp.20-28
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• 2005

In this paper, the methodology for the reliability estimation of buried pipeline with longitudinal gouges and dent is presented and the limit state of buried pipeline is formulated by failure assessment diagram(FAD). The reliability of buried pipeline with defects has been estimated by using a theory of failure probability. The failure probability is calculated by using the FORM(first order reliability method) and Monte Carlo simulation. The results out of two procedures have been compared each other. It is found that the FORM and Monte Carlo simulation give similar results for varying boundary conditions and various random variables. Furthermore, it is also recognized that the failure probability increases with increasing of dent depth, gouge depth, gouge length, operating pressure, pipe outside radius and decreasing the wall thickness. And it is found that the analysis by using the failure assessment diagram gives highly conservative results than those by using the theory of failure probability.