• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.8
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• pp.1599-1607
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• 2002

The purpose of this work is to suggest a new non-contact damage detection method for rotating ferromagnetic shafts. The presence and the location of a damage in rotating shafts are assessed by means of longitudinal elastic waves propagating along the shafts. These waves are measured by non-contact magnetostrictive sensors consisting of a coil and bias magnets. This paper shows the effectiveness of the sensors in the damage detection of rotating shafts. Several issues occurring in the application of the sensors to rotating shafts are carefully investigated.

• Journal of Environmental Health Sciences
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• v.11 no.1
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• pp.9-14
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• 1985

This experiment was carried out to study on the effect of SO$_2$ gas to chemical composition of tobacco leaves during flue-curing. The results were as follows: SO$_2$ gas in briquet was the major factor to damage with tobacco leaves. The damage only occured in a presence of moisture in tobacco leaves, it did not occured after color fix'lng stage which is a little leaf moisture. The danger of damage to tobacco leaves lies in 10ppm of SO$_2$ gas concentration. Follow with the SO$_2$ gas concentration increased, sugar and nitrogen contents became higher, polyphenol contents were loss, and the quality of tobacco leaves declined.

• Preventive Nutrition and Food Science
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• v.20 no.1
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• pp.52-59
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• 2015

This study was to investigate the preventive effect of taemyeongcheong (TMC, a Korean traditional health drink) on acetaminophen (APAP, 800 mg/kg BW)-induced hepatic damage in ICR mice. TMC is prepared from Saururus chinensis, Taraxacum officinale, Zingiber officinale, Cirsium setidens, Salicornia herbacea, and Glycyrrhizae. A high dose of TMC (500 mg/kg BW) was found to decrease APAP-induced increases in serum levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase. TMC pretreatment also increased the hepatic levels of hepatic catalase, superoxide dismutase, glutathione peroxidase, and glutathione, and reduced serum levels of the inflammatory cytokines tumor necrosis factor (TNF)-${\alpha}$ and interleukin (IL)-6 in mice administered APAP (P<0.05). TMC (500 mg/kg BW) reduced hepatic mRNA levels of TNF-${\alpha}$, IL-$1{\beta}$, IL-6, COX-2, and iNOS by 87%, 84%, 89%, 85%, and 88%, respectively, in mice treated with APAP (P<0.05). Furthermore, histological observations suggested TMC pretreatment dose-dependently prevented APAP-induced hepatocyte damage. These results suggest that TMC could be used as a functional health drink to prevent hepatic damage.

• Journal of the Korea Safety Management & Science
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• v.8 no.1
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• pp.17-26
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• 2006

Basis frame-work's base in a semiconductor industry have gas, chemical, electricity and various facilities in bring to it. That it is a foundation by fire, power failure, blast, spill of toxicant huge by large size accident human and physical loss and damage because it can bring this efficient, connect with each kind mechanical, physical thing to prevent usefully need that control finding achievement factor of human factor of human action. Large size accident in a semiconductor industry to machine and human and it is involved that present, in system by safety interlock defect of machine is conclusion for error of behaviour. What is not construing in this study, do safety in a semiconductor industry to do improvement. Control human error analyzes in human control with and considers mechanical element and several elements. Also, apply achievement factor using O'conner Model by control method of human error. In analyze by failure mode effect using actuality example.

• Earthquakes and Structures
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• v.9 no.1
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• pp.93-109
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• 2015

Based on the reconnaissance of buildings in Dujiangyan City during 2008 Wenchuan earthquake, China, structural damage characteristics and the spatial distribution of structural damage are investigated, and the possible reasons for the extraordinary features are discussed with consideration of the influence of urban historical evolution and spatial variation of earthquake motions. Firstly, the urban plan and typical characteristics of structural seismic damage are briefly presented and summarized. Spatial distribution of structural damage is then comparatively analyzed by classifying all surveyed buildings in accordance with different construction age, considering the influence of seismic design code on urban buildings. Finally, the influences of evolution of seismic design code, topographic condition, local site and distance from fault rupture on spatial distribution of structural damage are comprehensively discussed. It is concluded that spatial variation of earthquake motions, resulting from topography, local site effect and fault rupture, are very important factor leading to the extraordinary spatial distribution of building damage except the evolution of seismic design codes. It is necessary that the spatial distribution of earthquake motions should be considered in seismic design of structures located in complicated topography area and near active faults.

• Earthquakes and Structures
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• v.20 no.4
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• pp.389-403
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• 2021

Skewed bridges, being irregular structures with complicated dynamic behavior, are more susceptible to earthquake damage. Reliable seismic-resistant design of skewed bridges can be achieved by accurate determination of nonlinear seismic demands. However, the effect of geometric characteristics on the response modification factor (R-factor) is not accounted for in bridge design practices. This study attempts to investigate the effects of changes in the number of spans, skew angle and bearing stiffness on R-factor values and to assess the seismic fragility of skewed bridges. Results indicated that changes in the skew angle had no significant effect on R-factor values which were in consonance with code-prescribed R values. Also, unlike the increase in the number of spans that resulted in a decrease in the R-factor, the increase in bearing stiffness led to higher R-factor values. Findings of the fragility analysis implied that although the increase in the number of spans, as well as the increase in the skew angle, led to a higher failure probability, greater values of bearing stiffness reduced the collapse probability. For practicing design engineers, it is recommended that maximum demands on substructure elements to be calculated when the excitation angle is applied along the principal axes of skewed bridges.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.685-697
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• 2020

This study conducts meta-analysis of the effect size of related factors using research papers published within the past 20 years in relation to adolescent bullying experience in Korea. The verification results are as follows. First, in inducing factors, the overall effect size, personal psychology factor, and school life factor group showed a medium effect size. In the causative factors, the aggression, anxiety, stress, depression, suicidal thoughts, and school stress of school psychological factors showed a moderate effect size. Second, in terms of deterrent, the overall effect size, family environment factor, personal psychology factor, and school life factor group showed a medium effect size. In the sub-factors of determinants, the parenting attitude, parental support, and self-esteem and self-resilience of the family environmental factor group also showed a medium effect size. In conclusion, this study is meaningful in that it tried to quantitatively integrate the previous studies to examine objective results. It is meaningful that it provided basic data in program development and policy making to prevent and reduce the bullying of youth.

• Toxicological Research
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• v.30 no.1
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• pp.45-48
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• 2014

Helicobacter pylori (H. pylori) is the most important factor of gastric disease in clinical practice. Moreover, smoking, stress and a poor diet may be additive factors for gastric damage. With these factors, increasing infection of H. pylori triggers gastritis, gastric ulcers and gastric cancer. To develop a new protective agent, we are concerned with plant-derived extract. The extract of Coptis chinensis (C. chinensis) and its constituents were investigated to assess their protective activities against gastric damage. The C. chinensis extract showed a scavenging effect against 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radicals, inhibition of H. pylori colonization and antiulcerogenic activities in rat. In particular, palmatine derived from C. chinensis was found to be the novel protective agent. It is better than the C. chinensis extract, berberine, a well-known constituent of C. chinensis. We suggest that palmatine from the root cortex of C. chinensis may be a good candidate for the development of new pharmaceuticals to prevent gastric disease.

• Environmental Mutagens and Carcinogens
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• v.22 no.2
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• pp.83-89
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• 2002

The single cell gel electrophoresis (comet) assay is one of the useful tools for the study of genetic damage in humans exposed to environmental mutagens and carcinogens. This study was undertaken to evaluate the status of DNA damage in peripheral lymphocytes depending on their sex, age, smoking habits, and other factors in normal healthy Korean population. The 99 volunteers included in the study and out of these, 36 volunteers were smoker and 63 volunteers were non-smoker aged between 20-59 years. All individual answered a questionnaire that assessed their general information including smoking habits and the extent of the environmental tobacco smoke (ETS) exposure, and blood samples were obtained. There was a statistically significant difference in the extent of DNA damage between smoker and non-smoker (p<0.001). A significant difference was also observed between male and female (p<0.001) and amongst the different group of age (p<0.005), however, correlation analysis showed that only smoking habit was a significant factor for DNA damage. No significant effect of smoking duration, number of cigarettes smoking a day, SPY (smoke pack years) in smokers and environmental tobacco smoke exposure in non-smokers on the status of DNA damage was observed.

• Journal of Advanced Marine Engineering and Technology
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• v.21 no.5
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• pp.542-548
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• 1997

In this study an evaluation method of fatigue strength of membrane type LNG tank is presented with FEM analysis and experimental approach of seam and raised edge welds. The study contains the following : l)FEM analysis of test specimens 2)Fatigue tests of seam and raised edge welds 3)Estimation of cumulative damage factor of the welds on the basis of safe life design concept complying with the rules of classification society 4)Review of the effect of mean stress on the fatigue strength 5)Modelling of fatigue life of the welds which is changeable by weld heights With the results obtained in this study, a model ${\Delta}{\delta}/h^2=0.13553\;{N_{f}}^{-0.3151}$ for seam and raised edge welds having a given weld height is proposed to be useful for designers and inspectors.