• Journal of Korean Association for Spatial Structures
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• v.18 no.2
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• pp.59-67
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• 2018

Various pilotis are installed in the lower part of high rise buildings. Strong winds can generate sudden airflow around the pilotis, which can cause unexpected internal airflow changes and may cause damage to the exterior of the piloti ceiling. The present study investigates the characteristics of peak wind pressure coefficient for the design of piloti ceiling exteriors by conducting wind pressure tests on high rise buildings equipped with penetration-type and end-type pilotis in urban and suburban areas. The minimum peak wind pressure coefficient for penetration-type piloti ceilings ranges from -2.0 to -3.3. Minimum peak wind pressure coefficient in urban areas was 30% larger than in suburban areas. In end-type piloti ceilings, maximum peak wind-pressure coefficient ranges from 0.5 to 1.9, and minimum peak wind-pressure coefficient ranges from -1.3 to -3.6. With changes in building height, peak wind pressure coefficient decreases as the aspect ratio increases. Peak wind-pressure coefficient increases with taller pilotis. On the other hand, when piloti height decreases, the absolute value of the minimum peak wind pressure coefficient increases.

• Journal of Microbiology and Biotechnology
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• v.27 no.10
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• pp.1727-1735
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• 2017

Hepatitis E virus (HEV) infections cause epidemic or sporadic acute hepatitis, which are mostly self-limiting. However, viral infection in immunocompromised patients and pregnant women may result in serious consequences, such as chronic hepatitis and liver damage, mortality of the latter of which reaches up to 20-30%. Type I interferon (IFN)-induced antiviral immunity is known to be the first-line defense against virus infection. Upon HEV infection in the cell, the virus genome is recognized by pathogen recognition receptors, leading to rapid activation of intracellular signaling cascades. Expression of type I IFN triggers induction of a barrage of IFN-stimulated genes, helping the cells cope with viral infection. Interestingly, some of the HEV-encoded genes seem to be involved in disrupting signaling cascades for antiviral immune responses, and thus crippling cytokine/chemokine production. Antagonistic mechanisms of type I IFN responses by HEV have only recently begun to emerge, and in this review, we summarize known HEV evasion strategies and compare them with those of other hepatitis viruses.

• Journal of Ocean Engineering and Technology
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• v.25 no.5
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• pp.40-46
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• 2011

This study carried out a series of experiments involving impact tests (Drop weight type & Charpy type with a standard specimen and newly designed I-type specimen), hardness tests, and fracture surface observations of French-made roll shell steel (F), abnormal roll shell steel (M), reheated roll shell steel (R), and S25C steel under heat treatment conditions ($570^{\circ}C$) to analyze the cause and prevent the roll shell steel's brittle fracture and its damage.

• Journal of Korean society of Dental Hygiene
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• v.11 no.1
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• pp.127-136
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• 2011

Objectives : The writer aimed to examine the dynamic aspect on damage and to be conducive to the swift cure according to right treatment to educate prevention of injury through surveying on the number of the damaged teeth given injury, tooth kind, type in damage, place and cause for being damaged, frequency by month and by time level, and location of the damaged tooth. Methods : Targeting 343 teeth of receiving injury in 201 patients who visited the department of pediatric dentistry, the department of preservation, and the oral and maxillofacial surgery in a dental hospital in Cheonan city from April 2007 to April 2009, by having the dental injury as the main reason, the following conclusions were obtained. Results : 1. Deciduous teeth were indicated to be the highest in imperfect luxation with 60.7%, and were indicated to be in order of crown fracture with 25.5%, root fracture with 12.4%, and perfect luxation with 1.4%. The permanent teeth were indicated to be the highest in crown with 58.1%, and were indicated to be in order of imperfect luxation with 27.3%, root fracture with 13.1%, and perfect luxation with 1.5%(p<0.001). 2. In case of deciduous teeth for a place with damage, the home was indicated to be the highest with 31.7%. The permanent teeth were indicated to be the highest(p<0.001) in the road and stairs with 40.4%. As to a cause for damage, both deciduous and permanent teeth were indicated to be the highest(p<0.001) in a cause for falling with 53.1% and 30.8%, respectively. 3. As for a treatment method, in case of deciduous teeth, the close observation was indicated to be the highest with 46.9%. In permanent teeth, the resin restoration was indicated to be the highest(p<0.001) with 22.2%. Dental injuries in deciduous teeth and permanent teeth are showing diverse aspects. Conclusions : It is important to arrange guidelines on cure of the damaged teeth by injury through continuing a dynamic research on these aspects. Also, the damage in deciduous teeth may have direct and indirect influence upon growth in successional permanent teeth. Thus, through careful treatment, the injury needs to be minimized. It is considered to be likely necessary for a right coping method when injury occurs, and above all, for enough prior education so that injury cannot occur.

• International Journal of Highway Engineering
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• v.10 no.1
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• pp.75-85
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• 2008

Moisture damage of asphalt mixtures can occur because of a loss of bond between the asphalt binder and the fine and coarse aggregates. Therefore, moisture damage on asphalt pavements is the main cause of potholes, which is one of the main distress type of asphalt pavement. The purpose of this study is to evaluation effect moisture damage on material properties of asphalt mixtures through the laboratory performance test. The existing Modified Lottman test procedure was improved and the number of times that thermal cyclic conditioning can be added until the asphalt mixtures is damaged, was tested in order to exhibit the changes of the material properties because of moisture damage by immersion. Through the above experiments, it was found that the material properties of asphalt mixtures on room-temperature were rapidly decreased with loss of about 50% at initial stage of moisture damage caused by the amount of repeated immersion. Also, it was found that the property damage ratio using material properties of failure energy and $DCSE_f$ by test temperature $25^{\circ}C$ were showed a high relationship to moisture damage of the asphalt mixtures caused by the amount of repeated immersion.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.79-80
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• 2018

Recently, the interest in remodeling of new and old buildings is increasing worldwide. As a result, the frequency of use of architectural adhesives has increased. Currently, adhesives used in buildings are made of organic materials in most cases, and epoxy resin adhesives are most widely used. However, epoxy resin adhesives contain formaldehyde and VOCs in the room during construction, which can cause sick house syndrome. In case of building fire, it may cause damage due to carbon monoxide generated from organic materials. It is urgent to study the problem of epoxy fill adhesive made of such organic materials. Therefore, the purpose of this study is to investigate the effect of the adhesion of epoxy resin adhesive, which is a problem of epoxy resin adhesive, which is an existing organic adhesive by using inorganic materials such as magnesia and phosphate, And the inorganic adhesive which does not emit the release amount as an inorganic material.

• KIEAE Journal
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• v.7 no.6
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• pp.83-90
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• 2007

A mobile crane has been more frequently used to deal with the increased capital-intensive projects in line with the economic growth, but the operation is still heavily dependent on personal experience in the past, resulting in severe overturn accidents that cause the loss of lives and damage to the properties. A crane shall be installed in a systematic manner that proved to be safe in engineering aspect, and should the installation and operation be blindly dependent on experience alone, it would apparently cause a great risk. Particularly the mobile crane, among others, frequently causes a severe overturn accident due to poor ground-fixing device. The study therefore focused on fixing system of mobile crane and the outcome is highly expected to make a great commitment to selecting the optimal type of crane for the project as well as to securing the safety during construction.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.1
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• pp.26-35
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• 2017

The high-cycle fatigue cracking and the resonance generated in operation of a centrifugal compressor are main cause of the impeller damage. In order to prevent the damage, the impeller is designed or modified to have sufficient strength to withstand the operating condition. The damage prevent design will lead to a change of the flow condition and the performance characteristics of the compressor. In this study, the computational analysis were performed to identify the flow and the performance characteristics. The cases are a scalloped and a increased the blade thickness models with a closed type impeller. As the analysis results, the value of head coefficient and total to total efficiency for the increased the blade thickness model was decreased by each 0.5% and 0.1% than the values of the baseline model. Each value for the scalloped model was increased by 0.4% and was decreased by 1.6%.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.11a
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• pp.51-54
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• 2005

The concrete structure hasn't perfect waterproofing performance but if it doesn't have a joint part that could isolate a permeability. Concrete structure(communication tunnel and underground structure) has an expansion joint and construction joint. There are a lot of joint type after construction or expansion, shrinkage, vibration, over load, performance of decline etc.. they offer a water of way by variety change. In this reason, It carries in effect a waterproofing work for the concrete structure of waterproofing. but the structure has a behavior that cause a problem by waterproofing layer of damage, heaving phenomenon, temperature of shrinkage. In this study, we will estimate a field of application for Sealer of injection type for leakage maintenance of construction standard on the waterproofing performance.

• Proceedings of the PSK Conference
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• 2001.04a
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• pp.48-55
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• 2001

When an elongating RNA polymerase encounters DNA damage on the template strand of a transcribed gene it can either be arrested by or be transcribed through the lesion. Lesions that arrest RNA polymerases are thought to be subject to transcription-coupled repair, whereas that damage that is bypassed can cause miscoding, resulting in mutations in the transcript (transcriptional mutagenesis). We have developed a technique using a plasmid-based luciferase reporter assay to determine the extent to which a particular type of DNA base modification is capable of causing transcriptional mutagenesis in vivo. The system uses Escherichia coli strains with different DNA repair backgrounds and is designed to detect phenotypic changes caused by transcriptional mutageneis under nongrowth conditions. In addition, this method is capable of indicating the extent to which a particular DNA repair enzyme (or pathway) suppresses the occurrence of transcriptional mutagenesis. Thus, this technique provides a tool with which the effects of various genes on non-replication-dependent pathways resulting in the generation of mutant proteins can be gauged.