• Journal of the Earthquake Engineering Society of Korea
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• v.14 no.6
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• pp.45-53
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• 2010

The unseating failure of bridges, which is one of the most severe types of damage leading to the loss of transportation function, should be avoided in earthquakes. As a measure of prevention of unseating failure resulting from the failure of bearings, bearing-protection devices are frequently used. They are installed beside the bearings and protect the bearings by resisting a seismic load transmitted from the superstructure. In order to show appropriate seismic performance, the strength of anchors as well as of device bodies should be confirmed. In Korea, they have been installed only according to the design provided by device agents, because a proper design method for the anchors has not been established. In this study the performance of bearing-protection devices with various heights of concrete bed blocks has been investigated experimentally, and a proper design method has been proposed to secure seismic performance.

• Korean Journal of Veterinary Service
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• v.35 no.2
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• pp.133-137
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• 2012

Brucellosis, a bacterial zoonoses caused by the genus Brucella is responsible for abortion and infertility in cow. Brucellosis is causing economic loss in dairy industries and prevalent worldwide including Bangladesh but limited studies are devoted to determine the prevalence and its association with reproductive factors of dairy cows in Bangladesh. Therefore, the present study was conducted to determine the seroprevalence of brucellosis in dairy cattle using screening test Rose Bengal test (RBT) and the positive sera were further confirmed by indirect- ELISA. For this purpose, a total of 400 serum samples from dairy cows with history of abortion and various reproductive disorders were collected from the Kurigram district of Bangladesh for the detection of Brucella antibody. The overall prevalence of brucellosis in dairy cattle was 2.25%. Brucellosis in cases of abortion and repeat breeding was 8.3% and 2.8%, respectively. The results shows higher prevalence of brucellosis in cases of abortion followed by repeat breeding, while there was no seropositive cases from other reproductive disorders. Age-wise sero-prevalence was found 3.0% in 2~3 years age group and 2.0% in 4~8 years age group. The prevalence of brucellosis in indigenous and cross-bred cattle was 3.6% and 1.7%, respectively. All the animals detected positive to brucellosis by RBT were not found to be positive by i-ELISA. However, the RBT might be a suitable screening test for the diagnosis of Brucella infection in field condition in Bangladesh. These data will help to develop effective disease prevention strategies.

• International Journal of Oral Biology
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• v.43 no.3
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• pp.141-146
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• 2018

Periodontitis is generally a chronic disorder characterized by breakdown of tooth-supporting tissues, producing dentition loss. Porphyromonas gingivalis (P. gingivalis), a Gramnegative anaerobic rod, is one of the major pathogens associated with periodontitis. Neutrophils are first line defense cells in the oral cavity that play a significant role in inflammatory response. Xylitol is a known anti-caries agent and has anti-inflammatory effects. In this study, we conducted experiments to evaluate anti-inflammatory effects of xylitol on P. gingivalis infected neutrophils for possible usage in prevention and treatment of periodontal infections. P. gingivalis was intraperitoneally injected and peritoneal lavage was collected for cytokine determination. For in vitro study, neutrophils were collected from mouse peritoneal cells after zymosan injection or bone marrow cells. Neutrophils were stimulated with live P. gingivalis and ELISA was used to determine the effect of xylitol on P. gingivalis induced cytokine production. $IL-1{\beta}$, IL-6, $TNF-{\alpha}$ concentration and neutrophil population in the peritoneal lavage was increased in P. gingivalis-infected mouse. Peritoneal cells infected with live P. gingivalis revealed significantly increased production of $IL-1{\beta}$, IL-6 and $TNF-{\alpha}$ at multiplicity of infection of 10. Neutrophils from bone marrow and peritoneal lavage revealed increased production of $IL-1{\beta}$, IL-6 and $TNF-{\alpha}$. Xylitol significantly mitigated P. gingivalis induced cytokine production in neutrophils. Findings indicate that xylitol is an anti-inflammatory agent in neutrophils infected with live P. gingivalis, that suggests its use in periodontitis management.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.3
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• pp.363-368
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• 2010

Artemisia princeps has been utilized as a traditional medicine for a variety of diseases in Korea. In this study, we investigated the effects of Artemisia princeps extract (APE) on bone metabolism both in vitro using primary mouse bone marrow-derived macrophage and in vivo using ovariectomized rats. APE decreased the number of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells and TRAP activity. Also, APE inhibited bone resorptive activity of differentiated osteoclasts. In ovariectomized rats, APE alleviated the decrease in the trabecular bone mineral density. These results showed that APE might be useful for the prevention of postmenopausal bone loss.

• Journal of the Optical Society of Korea
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• v.18 no.1
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• pp.55-59
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• 2014

Sarcopenia, or reduced muscle mass and volume, is due to various factors such as senile change, neuronal degeneration, drug, malignancy, and sepsis. Sarcopenia with the aging process has been evidenced by the decline in muscle mass by 0.5 to 1% per year with 3-5% reduction in muscle strength for 10 years between the ages of 40 and 50, and a 1-2% of decline of mass every year in people aged 60-70. Therefore, early diagnosis and understanding the mechanism of sarcopenia are crucial in the prevention of muscle loss. However, it is still difficult to image changes of muscle microstructure due to a lack of techniques. In this study, we developed an animal model using denervated rats to induce a rapid atrophy in the tibialis anterior (TA) and imaged its structural changes using optical coherence tomography (OCT) along with histologic and ultrasound analyses. Ultrasound showed changes of overall muscle size. Histology revealed that the atrophic TA muscle displayed an increased size variability of muscle fiber and inflammatory changes. Three dimensional OCT imaged the changes of perimysial grid and muscle fiber structure in real time without sacrifice. These observed advantages of multimodal imaging using OCT and ultrasound would provide clinical benefits in the diagnosis of sarcopenia.

• Journal of Agricultural Extension & Community Development
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• v.18 no.3
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• pp.351-384
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• 2011

The purpose of this study is to look at the case of the German compensation system for farmers' accidents and to build a basic scheme in our country's compensation system for farmers' accidents. When you view examples of Germany, the social insurance scheme for farmers accidents in korea should be design as an independent institution from the existing industrial accident insurance, and it comes to relationships with other social insurance system, preferably with complementary personalities. A general rule of the compensation system applies to all farmers in principle but the coverage limits part-time farmers. Financial burden consists of the mix of insurance premium and state aid. The type and level of benefits is similar to the current industrial accident insurance, which give priority to places on economic security for keeping farmworks, such as cost for using temporary farmers, rather than income loss. In terms of financial system, pay-as-you-go system would be better because of immediate payment with the introduction of the compensation system. The compensation system might be managed and administrated by the existing nationwide organization. Of course, for operating of system review and further research on the technical details such as premium issues and funding problems of government support, the exact classification of the target coverage, premiums based on estimated income for the farmers' estimation, the exact statistical data on the accumulation of agricultural disaster is needed.

• Journal of Korea Water Resources Association
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• v.39 no.12 s.173
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• pp.1013-1022
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• 2006

Urban flooding is usually caused by the surcharge of storm sewers. For this reason, previous studies on urban flooding are mainly concentrated on the simulation of urban drainage systems. However these approaches that find the pipes which have insufficient drainage capacity are very approximate and unreasonable ways in establishing both flood prevention and flood-loss reduction planning. In this study, a two-dimensional model linked the existing ILLUDAS model is developed to calculate the accurate and resonable solution about urban flood inundation and it is verified by using the simulation of July 2001 flood in Seoul. In the urban area with a small difference of ground elevations, the two-dimensional flood propagation phases must be considered to make a accurate analysis for inundated area and depth. The result of this study can be used to construct fundamental data for a flood control plan and establish a urban flood forecasting/warning system.

• Fire Science and Engineering
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• v.34 no.3
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• pp.58-66
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• 2020

Households are categorized as exceptions in the Fire Services Act; oftentimes, the 'Golden Time' is missed at the early stages of a fire, resulting in loss of life. As such, due to the high number of deaths caused by household fires, the Korean government amended the Fire Services Act to make it mandatory for all detached houses to be equipped with a fire extinguisher from 2017 onwards. Only 34.8% of households were properly equipped with a fire extinguisher, according to the 2018 factual survey on fire extinguishing facilities in households conducted by the Fire Department. Fire extinguishers are crucial in case of fire but many households avoid them because they are red and have a rough aesthetic, which does not suit the household environment. There is now a need for diverse simple fire extinguisher designs so that they can be used as interior décor in the household in the day-to-day while being available for putting out a fire when necessary. If fire extinguishers have designs that go well with any household space like other decorative ornaments, this will greatly increase consumers' motivation to purchase them. It is greatly anticipated that various companies will work on developing designs for fire extinguishers to commercialize them for households in the future.

• KEPCO Journal on Electric Power and Energy
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• v.1 no.1
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• pp.1-8
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• 2015

When the line and switchgear of the substation system are disconnected, ferro-resonance can occur. This happens even if the capacitive reactance and inductive reactance are not equal, which are not common resonance conditions. Resonance conditions vary depending on the busbar configuration environment. Although the damping resistance method applying the existing saturable reactor to cope with ferro-resonance has been successfully applied on site, there can be loss of normal function during long-term operation. The reason is because the rise in the operating frequency of saturable reactors means the saturation number is increased. Therefore, it can no longer function as saturable reactor since the resistor having inadequate capacity is burned out. To address this problem, in this paper, an EMTP-based simulation test was performed by designing and applying a dual reactor method, which adds an extended divergence reactor to the 1st side of the VT. The test result confirms that when the divergence reactor is inserted, the voltage and current values obtained at the 1st side and 2nd side of the VT as well as current values of divergence reactor part were stabilized from the transient phenomena and return to normal values. When compared with existing measures, although this method is similar in adding having a reactor added to a system regarding ferro-resonance, it has the advantage of being able to prevent ferro-resonance in advance since the reactor is added before the system is saturated. In addition, because it does not use damping resistance, it can extend the equipment life and stabilize its operation. Therefore, there are a lot of differences in terms of its operating characteristics and achivement of goal between the conventional method and new divergence reactor method.

• Journal of the Korean Institute of Gas
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• v.17 no.4
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• pp.39-44
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• 2013

There have been large explosions at some chemical plants recently. Accidents in chemical plants have been caused mainly by servicing for maintenance. There is a need to find a key target for effective injury prevention in maintenance. In this paper, facilities were selected as a key target and the risk priority numbers of the facilities were calculated in order to prioritize preventative measures. The research method was based on the followings; the list of the facilities is found through injury analysis. Then, the risk of each facility was calculated by the frequency of accidents and the working day loss through injuries. In addition, the risk of the facilities was calculated again by the frequency and the severity based on knowledge and experience of experts. As a result, the facilities in chemical plant maintenance are ranked in order of high to low risk priority number; reactor, dryer, tank lorry, etc. In the future, special measures and attention should be directed according to the risk priority number during the maintenance of chemical plants.