• Structural Monitoring and Maintenance
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• v.5 no.2
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• pp.231-242
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• 2018

Subway tunnel structure has been rapidly developed in many cities for its strong transport capacity. The model-based damage detection of subway tunnel structure is usually difficult due to the complex modeling of soil-structure interaction, the indetermination of boundary and so on. This paper proposes a new data-based method for the damage detection of subway tunnel structure. The root mean square acceleration and cross correlation function are used to derive a statistical pattern recognition algorithm for damage detection. A damage sensitive feature is proposed based on the root mean square deviations of the cross correlation functions. X-bar control charts are utilized to monitor the variation of the damage sensitive features before and after damage. The proposed algorithm is validated by the experiment of a full-scale two-rings subway tunnel lining, and damages are simulated by loosening the connection bolts of the rings. The results verify that root mean square deviation is sensitive to bolt loosening in the tunnel lining and X-bar control charts are feasible to be used in damage detection. The proposed data-based damage detection method is applicable to the online structural health monitoring system of subway tunnel lining.

• The Korea Journal of Herbology
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• v.27 no.1
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• pp.51-58
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• 2012

Objectives : This study was performed to investigate effect of evodiae fructus on acute reflux esophigitis rat induced by pylorus and forestomach ligation operation. Methods : Twenty-four laboratory rats were divided four groups and each group had six rats ; normal intact group, acute reflux esophagitis (RE) control group, two experiment RE group treated extract of evodiae fructus 600 mg/kg (EEF600) and 300 mg/kg (EEF300). All rats was fasted for 18 hr but free water, we induced RE by pylorus and forestomach ligation operation. Intact group and RE control group rats were orally administered a distilled water and two experiment groups were orally administed with EEF 600 mg/5ml/kg and 300 mg/5ml/kg. One hour after, rats were anesthetized, intact group was cut the abdomen open and sutured with 2.0 silk thread. RE control group and EEF group were cut the abdomen open, ligated pyloric canal and forestomach with 2.0 silk thread and sutured. Six hour after the operation, rats were sacrified, collected bloods in the abdominal vein, disectted a esophagus and stomach. The stomach was washed a 1 ml PBS and the esophagus was cut longitudinally and pictured a innter mucosa area to research damages in esophagus. Results : The esophagic tissue damage percentage of reflux esophagitis rat was increased compared to that of normal intact group. But esophagic damage percentage of EEF 600 were significantly decreased compared to that of RE control group. But there was no difference on gastric juice pH between control RE, alpha-tocopherol administration rat group and EEF administration rat group. In esophagus of RE control rat, gastric damage occurred severely and injury percentage of mucosa were increased, but EEF 600 mucous inflammatory damage percentage was significantly compared to that of RE control group. Proinflammatory cytokines such as TNF-alpha, IL-1beta and IL-6 in serum on RE control group were markedly grew than those of intact rat, those of vechicle group treated with EEF 600 and EEF 300 were remarkably decreased compared to production of proinflammatory cytokine of RE control group. In microscopic observation, intact group rat had no hyperemia, mucous injury and exclusion, ulcer and edema. But it could showed mucosa damages, submucosa edema and ulcer in RE control. However, administration of EEF 600 and EEF 300 made esophagus have less inflammation and injury by gastric acid. Conclusions : The results suggest that antiinflammatory Effect of EEF could attenuate the severity of reflux esophagitis and prevent the esophageal mucosal damage, and validate its therapeutic use in esophageal reflux disease.

• Journal of the Earthquake Engineering Society of Korea
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• v.19 no.6
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• pp.273-282
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• 2015

In this study, shaking table test has been carried out for the dual frame passive control system for seismic performance verification of the proposed system. The proposed system was separated into two independent frameworks that are strength resistant core and frame structure by connecting to the damper. Moreover, the seismic performance improvement of the proposed system has been verified by comparing and analyzing the experimental results of the proposed system with an existing core system. As a result of the shaking table test, acceleration and displacement responses of dual-frame vibration control system are decreased than those of the existing strength resistant type core system. In the case of the core system, while the damage was concentrated on the column of first floor, the damage of the dual system was dispersed in each layer. The damage also was concentrated on the damper, almost no damage occurs to the structural members. It has been emphasized that installed dampers in the proposed dual system reduce the input energy of whole structure by absorbing seismic input energy, which leads overall system damage to be reduced.

• Structural Engineering and Mechanics
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• v.75 no.4
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• pp.415-424
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• 2020

Recently, many structural damage detection (SDD) methods have been proposed to monitor the safety of structures. As an important modal parameter, mode shape has been widely used in SDD, and the difference of vectors was adopted based on sensitivity analysis and mode shapes in the existing studies. However, amplitudes of mode shapes in different measured points are relative values. Therefore, the difference of mode shapes will be influenced by their amplitudes, and the SDD results may be inaccurate. Focus on this deficiency, a multi-strategy SDD method is proposed based on the included angle of vectors and sparse regularization in this study. Firstly, inspired by modal assurance criterion (MAC), a relationship between mode shapes and changes in damage coefficients is established based on the included angle of vectors. Then, frequencies are introduced for multi-strategy SDD by a weighted coefficient. Meanwhile, sparse regularization is applied to improve the ill-posedness of the SDD problem. As a result, a novel convex optimization problem is proposed for effective SDD. To evaluate the effectiveness of the proposed method, numerical simulations in a planar truss and experimental studies in a six-story aluminum alloy frame in laboratory are conducted. The identified results indicate that the proposed method can effectively reduce the influence of noises, and it has good ability in locating structural damages and quantifying damage degrees.

• The Korea Journal of Herbology
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• v.21 no.3
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• pp.47-54
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• 2006

Objectives : This study was performed to compare the preventive effect of water extracts from Injinho-tang and Haninjinho-tang on hyperlipidemia and liver damage induced by alcohol. Methods : Except for the normal group, we fed rat on 25% alcohol for 55 days. And each extract was administrated for the same period. We measured the serum component in rat's blood, body weight and weight of liver. Results : 1. At first, we observed effects of Injinho-tang and Haninjinho-tang on hyperlipidemia induced by alcohol. Injinho-tang group showed significant decrease of triglyceride, body weight in comparison with those of the control group. Haninjinho-tang group showed significant decrease of total cholesterol, triglyceride in comparison with those of the control group. I 2. At second, we observed effects of Injinho-tang and Haninjinho-tang on liver damage induced by alcohol. lnjinho-tang group showed significant decrease of AST (aspartate aminotransferase), ALT (alanine aminotransferase), ALP (alkaline phosphatase), liver weight in comparison with those of the control group. Haninjinho-tang group showed significant decrease of AST (aspartate aminotransferase), ALT (alanine aminotransferase) in comparison with those of the control group. Conclusion : Reviewing these experimental results, it appears that water extracts from Injinho-tang and Haninjinho-tang have pharmaceutical preventive efficacy on hyperlipidemia and liver damage induced by alcohol. Therefore further additional study should be conducted to elucidate in depth the pharmaceutical efficacy of these.

• The Korea Journal of Herbology
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• v.30 no.3
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• pp.77-82
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• 2015

Objectives : The Korean medical doctors use PMR(Polygoni Multiflori Radix) for nourishing the liver-kidney, loosing the bowel to relieve constipation, recovering from malaria, and clearing away heat and eliminating toxin, etc. But, this study was performed to investigate the effect of water extracts from PMR on prevention of hyperlipidemia and liver damage induced by alcohol. Methods ： Except for the normal group, we fed rat on 25% alcohol for 55 days. And the extract was administrated for the same period. We measured the serum components in rat's blood, body weight and weight of liver. Results ： At first, we observed effects of PMR on prevention of hyperlipidemia induced by alcohol. PMR group showed significant decrease of total cholesterol and triglyceride in comparison with those of the control group. PMR group showed significant increase of body weight in comparison with those of the control group in 4weeks and 8weeks. At second, we observed effects of PMR on prevention of liver damage induced by alcohol. PMR group showed significant decrease of GOT, GPT, ALP, and LDH in comparison with those of the control group. PMR group showed significant increase of liver weight in comparison with those of the control group. Conclusions ： Reviewing these experimental results, it appears that water extracts from PMR have pharmaceutical efficacy on prevention of hyperlipidemia and liver damage induced by alcohol. Therefore further additional study should be conducted to elucidate in depth the pharmaceutical efficacy of these.

• Korean Journal of Organic Agriculture
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• v.22 no.2
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• pp.269-280
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• 2014

This study was performed to test the insecticidal and antimicrobial activity of plant extracts from clove, Sophora flavescens Aiton and neem. As the result of antimicrobial activity test, clove extract showed the strongest activity against Botrytis cinerea. In insecticidal activity test, the extract of Sophora flavescens Aiton was the highest against Nilaparvata lugens. The pyroligneous liquor (10%) and emulsified spreader (10%) were added to the extracts of clove and Sophora, respectively, to apply the environment-friendly rice field. In the field treated clove extract, disease damage occurred 49.1% and insect damage occurred 29.5% compared to control plot (100%). In the field treated Sophora extract, disease damage was 56.7% and insect damage was 21.0% compared to control plot (100%). In conclusion, plant extracts from Sophora and clove could control about 50% of disease and about 70% of insect damage that they could be used as environment-friendly resources to control disease and insect in rice farming.

• Journal of Nutrition and Health
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• v.40 no.8
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• pp.701-707
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• 2007

This study was to investigate lipid peroxidation, antioxidant enzyme activity and DNA damage after exercise, and the protective effect of garlic against exercise-induced oxidative stress. Male Sprague-Dawley rats(4 weeks old) were randomly divided into three groups of 6 rats each; control group(Con) without garlic and exercise, Ex group with exercise alone, and Ex-G group with 2% garlic and exercise. For 4 weeks, rats were given diets containing 15% corn oil and 1% cholesterol with or without garlic. The swimming was selected as a model for exercise performance. Rats swam for 40 min a day, for 5 days a week. Group Ex and Ex-G showed significant lowering in body weight gain and fat accumulation compared to control. No significant changes were observed in levels of plasma cholesterol and triglyceride among three groups, demonstrating that exercise and garlic had no effects on changes of blood lipid. This finding of blood lipid seems to be due to higher plant sterol content in corn oil. The DNA tail moment of lymphocytes showed greater tendency in Ex and Ex-G than in control, but garlic supplements failed to suppress DNA damages. Compared to control, Ex had higher plasma TBARS which was lowered to the control's level in Ex-G with 2% garlic supplementation(p<0.05). Ex-G led to a higher hepatic superoxide dismutase(SOD) activity than control and Ex(p<0.05). Activity of hepatic catalase was also increased in Ex-G, while in Ex it was significantly low(p<0.05). It seemed that TBARS levels were related to the activities of SOD and catalase, and that garlic contributed to increasing the enzyme activities and led to decrease of TBARS. These results demonstrate that lipid peroxidation and DNA damage occur as a consequences of oxidative stress after exercise, and that antioxidant defense against oxidative stress could be enhanced by garlic supplementation through the induction of antioxidant enzymes. However, further investigations should be done on the garlic effect on DNA damage.

• Clinical and Experimental Pediatrics
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• v.56 no.10
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• pp.446-450
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• 2013

Purpose: This study evaluated the extent of damage due to hypothermia in the mature and immature brain. Methods: Hippocampal tissue cultures at 7 and 14 days in vitro (DIV) were used to represent the immature and mature brain, respectively. The cultures were exposed at $25^{\circ}C$ for 0, 10, 30, and 60 minutes (n=30 in each subgroup). Propidium iodide fluorescent images were captured 24 and 48 hours after hypothermic injury. Damaged areas of the cornu ammonis 1 (CA1), CA3, and dentate gyrus (DG) were measured using image analysis. Results: At 7 DIV, the tissues exposed to cold injury for 60 minutes showed increased damage in CA1 (P<0.001) and CA3 (P=0.005) compared to the control group at 48 hours. Increased damage to DG was observed at 24 (P=0.008) and 48 hours (P=0.011). The 14 DIV tissues did not demonstrate any significant differences compared with the control group, except for the tissues exposed for 30 minutes in which DG showed less damage at 48 hours than the control group (P=0.048). In tissues at 7 DIV, CA1 (P=0.040) and DG (P=0.013) showed differences in the duration of cold exposure. Conclusion: The immature brain is more vulnerable to hypothermic injury than the mature brain.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.6
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• pp.1364-1368
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• 1999

This study was carried out to investigate the inhibiton effects of Coprinus comatus ethanol extract of edible mushroom on liver damage in benzo(a)pyrene (B(a)P) treated mice. The activities of serum aminotransferase, cytochrome P 450 and hepatic content of lipid peroxide after B(a)P treatment were increased than those of control, but those levels were significantly decreased by the treatment of Coprinus comatus ethanol extract. Whereas, the hepatic glutathione content and glutathione S transferase activity were decreased by B(a)P treatment than those of control, but those were increased by the treatment of Coprinus comatus ethanol extract. Also the activities of superoxide dismutase, catalase and glutathione peroxidase after B(a)P treatment were markedly increased than those of control, but those levels were decreased by the treatment of Coprinus comatus ethanol extract. These results suggest that Coprinus comatus ethanol extract have a protective effect on liver damage by benzo(a)pyrene through the mechanisms of decreasing lipid peroxide and activities of free radical generating enzymes.