• Genomics & Informatics
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• v.17 no.1
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• pp.2.1-2.12
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• 2019

Chronic obstructive pulmonary disease (COPD) is a type of progressive lung disease, featured by airflow obstruction. Recently, a comprehensive analysis of the transcriptome in lung tissue of COPD patients was performed, but the heterogeneity of the sample was not seriously considered in characterizing the mechanistic dysregulation of COPD. Here, we established a new transcriptome analysis pipeline using a deconvolution process to reduce the heterogeneity and clearly identified that these transcriptome data originated from the mild or moderate stage of COPD patients. Differentially expressed or co-expressed genes in the protein interaction subnetworks were linked with mitochondrial dysfunction and the immune response, as expected. Computational protein localization prediction revealed that 19 proteins showing changes in subcellular localization were mostly related to mitochondria, suggesting that mislocalization of mitochondria-targeting proteins plays an important role in COPD pathology. Our extensive evaluation of COPD transcriptome data could provide guidelines for analyzing heterogeneous gene expression profiles and classifying potential candidate genes that are responsible for the pathogenesis of COPD.

• Journal of Ocean Engineering and Technology
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• v.13 no.2 s.32
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• pp.90-98
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• 1999

Boiler high-temperature pipelines such as main steam pipe, header and steam drum in fossil power plants are degraded by creep damage due to severe operationg conditions like high temperature and high pressure for an extended period time. Such material degradation lead to various component faliures causing serious accidents at the plant. Conventional measurement techniques such as replica method, electric resistance method, and hardness test method have such disadvantages as complex preparation and measurement procedures, too many control parameters, and therefore, low practicality and they were applied only to component surfaces with good accessibility. In this study, both artificial creep degradation test using life prediction formula and frequency analysis by ultrasonic tests for their preparing creep degraded specimens have been carried out for the purpose of nondestructive evaluation for creep damage which can occur in high-temperature pipelline of fossil power plant. As a result of ultrasonic tests for crept specimens, we confirmed that the high frequency side spectra decrease and central frequency components shift to low frequency bans, and bandwiths decrease as increasing creep damage in backwall echoes.

• Journal of Ocean Engineering and Technology
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• v.13 no.3 s.33
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• pp.100-107
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• 1999

Due to the high temperature and pressure, the materials of pipeline in power plant are degraded by creep damage. So far, many conventional measurement techniques such as replica method, electric resistance method, adn hardness test method for creep damage have been used. Among them, the replica method has mainly been used for the inspection of components. But this technique is restricted to the applications at the surface of the objects and cannot be used to material inside. In this paper, the measuring methods of evaluation by using ultrasonic attenuation and electric resistance for the creep detection of creep damage in the form of cavities on grain boundaries or intergranular microcracks were carried out. Absolute measuring method of quantitave ultrasonic attenuation technique for 1Cr0.5Mo material degradation was analyzed for determining the creep degradation steps using life prediction formula. As a result of measurement for creep specimens, we founded that the coefficient of utrasonic attenuation was increased as the increase of creep life fracton(${phi}c$) and the decreasing rate of wlwctric resistance was also increased.

• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.1
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• pp.10-17
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• 2000

In boiler high-temperature pipelines such as main steam pipe, header and steam drum in fossil power plants, conventional measurement techniques(replica method, electric resistance method, and hardness test method) for measuring creep damage have such disadvantages as complex preparation and measurement procedures, too many control parameters. And also, these techniques have low practicality and applied only to component surfaces with good accessibility. It needs to apply a reliable and quantitative ultrasonic nondestructive evaluation method that can be replaced for these equipment. In this study, both artificial creep degradation test using life prediction formula and frequency analysis by ultrasonic tests for crept specimens were carried out for the purpose of nondestructive evaluation for creep damage. As a result of ultrasonic tests for crept specimens, we conformed that the high frequency side spectra decrease and central frequency components shift to low frequency band, and also their bandwidth decreases as increasing creep damage in backwall echos.

• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.1
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• pp.18-26
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• 2000

Boiler high-temperature pipelines such as main steam pipe, header and steam drum in fossil power plants are degraded by creep damage due to severe operating conditions such as high temperature and high pressure for an extended period time. Conventional measurement techniques(replica method, electric resistance method, and hardness test method) for measuring creep damage have such disadvantages as complex preparation and measurement procedures, too many control parameters. And also these techniques have low practicality and applied only to component surfaces with good accessibility. In this paper, artificial creep degradation test and ultrasonic measurement for their creep degraded specimens(Cr-Mo alloy steels) were carried out for the purpose of evaluation for creep damage. Absolute measuring method of quantitative ultrasonic measurement for material degradation was established, and long term creep degradation tests using life prediction formula were carried out. As a result of ultrasonic tests for crept specimens. we conformed that both the sound velocity decreased and attenuation coefficient linearly increased in proportion to the Increase of creep life fraction($\Phi$c).