• Journal of the Korean Society for Nondestructive Testing
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• v.19 no.1
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• pp.25-33
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• 1999

Since concrete is an inhomogeneous material consisting of larger aggregates and sand embedded in a cement paste matrix, it relatively shows a complex failure mechanism. In order to assure the reliability of concrete structure. microscopic fracture behavior and internal damage progress of concrete under the loading should be fully understood. In this study, an acoustic emission(AE) technique has been used to clarify microscopic failure mechanism and their corresponding AE signal characteristics of concrete under three-point bending test. In addition 2-dimensional AE source location has been performed to monitor the progress of an internal damage and the successive crack growth behavior during the loading. The relationship between AE signal characteristics and microscopic fracture mechanism is discussed.

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.2
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• pp.133-139
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• 2003

In order to extend the life time of building and civil infra-structure, nowadays, patch type fibrous composite materials are widely used. Repaired concrete columns and beams gain the stiffness and strength, but they lose toughness and show brittle failure. Usually, the cracks of concrete structures are visible with naked eyes and the status of the structure in the life cycle is estimated with visible inspection. After repairing of the structure, crack visibility is blocked by repaired carbon sheets. Therefore, structural monitoring after repairing is indispensible and self diagnosis method with optical fiber sensor is very useful. In this paper, peel-out effects is detected with optical fiber sensors and the strain difference between main structure and repaired carbon sheets when they separate each other.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.4
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• pp.323-329
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• 2004

Water vapor is an important parameter in monitoring changes in the Earth's climate and it can be used to improve weather forecasting. However, it haven't observed accurately by reasons of structural and economic problem of observation. GPS meteorology technique for precipitable water vapor measurement is currently actively being researched an advanced nation. Main issue of GPS meteorology is an accuracy of PWV measurement related weighted mean temperature and meteorological data. In this study, the korean weighted mean temperature had been recalculated by a linear regression method based on meteorological observations from 6 radiosonde stations for 2003 year. We examined the accuracy of PWV estimates from GPS observations and Radiosonde observations by new korean weighted mean temperature and others.

• Korean Journal of Remote Sensing
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• v.27 no.3
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• pp.339-351
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• 2011

This study investigates the potentials of satellite, ground measurement data, and geo-spatial information within an urban area for the mapping of the Urban Environmental Quality (UEQ) parameters. The UEQ indicates a complex and various parameters resulting from both human and natural factors, which are greenness, climate, air pollution, the urban infrastructure, and etc. Multi-spectral remote sensing data from the Landsat ETM and TM sensors for the mapping of air pollution by the Haze Optimized Transform (HOT) technique, Urban Heat Island (UHO using the emissivity-fusion method in Seoul from 2000 to 2006 in fine resolution (30m) were analyzed for the estimation of UEQ index. Although the UHI values are similar ($8.4^{\circ}C{\sim}9.1^{\circ}C$) during these years, the spatial coverage of "hot" surface temperature (> $24^{\circ}C$) significantly increased from 2000 to 2006 due to the rapid urban development. Furthermore, high correlations between vegetation index and land surface temperature were achieved with a correlation coefficients of 0.85 (2000), 0.81 (2001), 0.84 (2002), and 0.89 (2006), respectively. It was found that the proposed method was successfully analyzed spatial structure of the UEQ and the scenarios of the best and worst areas within the city were also identified. Based on the quantifiable fine resolution satellite image parameters, UEQ can promote the understanding of the complex and dynamic factors controlling urban environment.

• Journal of Trauma and Injury
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• v.26 no.4
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• pp.280-285
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• 2013

Purpose: Nowadays, non-operative management increases in patients with blunt splenic injury due to development of diagnostic and interventional technique. The purpose of this study is to evaluate the management in patients with blunt splenic injury and effect of clinical state such as shock on the choice of management. Methods: From April 2007 to July 2013, we retrospectively reviewed the medical charts of fifty patients who had splenic injury after blunt trauma. The demographic characteristics, American Association for the Surgery of Trauma (AAST) grade of splenic injury, management method (emergency operation, angiographic embolization or observation) and clinical outcome were analyzed. Results: The mean age was $41.5{\pm}21.4$ years and male was 44(88%). Twenty patients(40%) were in shock condition initially and five patients(10%) underwent emergency operation due to hemodynamic instability. Emergency angiographic embolization was performed in 20 patients(40%) and 25 patients were managed conservatively. When patients were divided into shock group (SG) and non-shock group (NSG), Patients in SG had significantly higher serum lactate level and base deficit than NSG (lactate; $4.5{\pm}3.4$ mmol/L, base deficit; $5.8{\pm}4.4$ mmol/L vs $1.9{\pm}1.4$ mmol/L, $2.8{\pm}2.5$ mmol/L, p=0.007, p=0.013). There was no significant difference of AAST grade and contrast blush rate in abdomen CT between two groups. Among 45 patients with non-operative management, four patients(8.9%) got delayed angiographic embolization and 3 patient died from companied organ injury. Conclusion: Non-operative management can be acceptable management option in patients with splenic blunt trauma under intensive hemodynamic monitoring.

• Journal of Korea Water Resources Association
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• v.48 no.12
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• pp.995-1009
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• 2015

Weather radar rainfall data has been recognized for making valuable contributions to short-term flood forecasting and management over the past decades. There are several advantages to better monitoring rainfall in ungauged area compared to ground-based rain gauges with which spatial patterns of the rainfall are not effectively identified. Hence, this study aims to develop a new scheme to forecast spatio-temporal rainfall field. The proposed model was based on an advection scheme to track wind patterns and velocity. The results showd a promising forecasting skill with quantitative and qualitative measures. It was confirmed that the forecasted rainfall may be effectively used an input data for a distributed hydrological model.

• Journal of Korea Water Resources Association
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• v.41 no.2
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• pp.173-184
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• 2008

Climatic water balance has been applied to obtain quantity of various hydrologic components. Hydrologic information is estimated by comparison between rainfall and evapotranspiration under complex terrain condition. Water deficit is defined as that subtraction of actual supply from climatic demand. The water deficit will occur, when monthly evapotranspiration exceed monthly rainfall. Contrary water surplus is defined as that surplus water after meeting the demand by plants. The water surplus will be occurred when monthly rainfall exceeds monthly evapotranspiration. Finally, the discrete moisture indices were calculated and mapped for the whole watershed to estimate dryness and wetness status using the climatic water balance approach. The result of this study can properly interpret the real drought and non drought. Based upon the results, it can be concluded that the climatic water balance model is useful to monitor water conditions for the watershed.

• Analytical Science and Technology
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• v.8 no.4
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• pp.869-876
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• 1995

The active sites of the nickel and iron-containing enzyme, carbon monoxide dehydrogenase (CODH) from clostridium thermoaceticum were investigated using Electron Paramagnetic Resonance (EPR) technique. CODH exhibits several spectral features called NiFeC, $g_{ave}=1.82$, $g_{ave}=1.86$. FCII signals which are originated from different clusters in this enzyme. CODH is know to catalyze two different kinds of reactions - acetyl-CoA synthesis and CO oxidation. The acetyl-CoA synthesis activity can be followed by monitoring CO/acetyl-CoA exchange. The addition of 1,10-phenanthroline (phen) to CODH selectively destroyed the CO/acetyl-CoA exchange activity and eliminated the NiFeC signal completely. CO oxidation activity and other EPR signals were unaffected. Such behavior demonstrates that CODH has two distinct active sites and that the NiFe complex is only responsible for the CO/acctyl-CoA exchange activity. Phen caused the removal of only 30% of Ni in the NiFe complex ($0.3Ni/{\alpha}{\beta}$) as shown by the quantitative metal analysis. The phen-treated CODH could be reactivated fully by incubation In $Ni^{2+}$ solution. Radioactive $^{63}Ni^{2+}$ was used to quantitate the amount of the $Ni^{2+}$ incorporated into phen-treated enzyme and showed that the amount was the same as the removed by the phen treatment. i.e. $0.3Ni/{\alpha}{\beta}$. This indicates that only 30% of NiFe complexes are labile and responsible for the CO/acctyl-CoA exchange activity, the other 70% are non-labile and have no exchange activity. This is the first clear evidence that the NiFe complex is heterogencous and labile and non-labile Ni sites arc interacting differently with substrates and chelating agents like phen.

• The Journal of the Korean Society for Microbiology
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• v.35 no.4
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• pp.299-308
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• 2000

Recently developed cDNA microarray or DNA chip technology allows expression monitoring of expression of hundreds and thousands of genes simultaneously and provides a format for identifying genes as well as changes in their activity. In order to search for changes in gene expression after X irradiation in HL60 cells, cDNA microarray technique was done. In this study, expression of 588 human genes (including oncogenes, tumor suppressor genes, cell cycle regulator genes, intracellular signal transduction modulator genes, apoptosis related genes, transcription factor genes, growth factors and receptor genes, cytokine genes, etc) were analyzed. For cDNA microarray analysis mRNAs were extracted from control and 8 Gy-irradiated HL60 cells. As a result the changes in expression of several genes were observed. This alteration of gene expression was confirmed by reverse transcription-polymerase chain reaction. The expression of heat shock 60 KD protein, c-jun, erythroid differentiation factor, CPP32, myeloid cell nuclear differentiation antigen, MAP kinase-activated protein kinase, interleukin-8, monocyte chemotactic peptide 1 and RANTES genes was increased, but the expression of p55CDC gene was decreased after X irradiation.

• The Journal of the Korea Contents Association
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• v.13 no.10
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• pp.37-45
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• 2013

In recent years, the demands of multimedia data in wireless sensor networks have been significantly increased for the high-quality environment monitoring applications that utilize sensor nodes. However, since the amount of multimedia data is very large, the network lifetime is significantly reduced due to excessive energy consumption on particular nodes. To overcome this problem, in this paper, we propose a high efficiency data compression scheme in wireless multimedia sensor networks. The proposed scheme reduces the packet size by a multiple compression technique that consists of primary compression that deletes the lower priority bits considering characteristics of multimedia data and secondary compression based on Chinese Remainder Theorem. To show the superiority of our scheme, we compare it with the existing compression scheme. Our experimental results show that our proposed scheme reduces the amount of transmitted data by about 55% and increases network lifetime by about 16% over the existing scheme on average.