• Fashion & Textile Research Journal
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• v.7 no.1
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• pp.70-74
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• 2005

This study was aimed to isolation and identification of attached bacteria on the clothes excavated from Deajeon area dating on the 16th century. From the observation with colony shape, 17 bacterial strains were isolated, and then 7 bacterial strains were identified with morphological and biochemical characteristics. Streptococcus sp., Alcaligenes faecalis, Gemella sp., Acinetobacter sp., Pseudomonas vesicularis, Aeromonas sain. salmonicida, Moraxella spp. In observation of the bacterial strains by the sort of textile, more bacterial strains were found in silk, cotton, and cotton batt than in ramie and hemp. It is suggest that hemp has antibacterial characteristics due to the presence of lignin. In the comparison washed samples with unwashed ones, there were more kinds of bacterial strains in washed samples. In the cellulase activity tests, all isolated bacteria had low level cellulase activity.

• Journal of Internet Computing and Services
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• v.21 no.5
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• pp.31-37
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• 2020

Last year's Goseong-Sokcho forest fires have highlighted the limitations of extinguishing work for night-time forest fire and the importance of quick identification for information on the spread of forest fire. However, it is not easy to find services that take into account the characteristics of forest fires, as most existing disaster-related mobile applications and research assume various disaster situations rather than just forest fire situations. Therefore, a system that can provide information quickly is needed, taking into account the characteristics of forest fires and the limitations of extinguishing work. In this paper, we propose evacuation route guidance services that bypass areas where fire has already spread, supplement existing methods of extinguishing work, and provide general information on forest fire situations in real time, by putting drones into forest fire situations. It has been implemented to automate image analysis using the Rekognition service of Amazon Web Service (AWS), and the results of fire detection and the T Map API guide the evacuation path. It is expected that the results of this paper will allow efficient and rapid rescue and extinguishing work to be carried out, and further reduce the damage of human life caused by forest fires.

• Corrosion Science and Technology
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• v.8 no.4
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• pp.153-156
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• 2009

The water cooling system for VFD (Variable Frequency Drive) of a fossil fuel power plant was reported to be shut down due to a water leak at the metal connection of the heat-sink to the hoses. In order to identify the cause of the failure, the system was visually inspected, and corrosion products were analyzed with SEM equipped with EDX. The failure was observed repeatedly at the nipples of certain location, suggesting galvanic corrosion. In a U-shaped heat sink with two nipples, for inlet and outlet, only one nipple was corrosively damaged at the tip, while the other was not. Most of the corrosion products were observed at the sound nipple and in the filter, identified as $Cu(OH)_2$. Some other corrosion products, composed of mostly $Cu_2O$, were found at the corrosively attacked nipple. A fair amount of Cl was also detected on the surface of the damaged nipple. It was concluded that galvanic corrosion was occurred due to a current leakage over the whole system, and the damage was accelerated by the accumulated chlorine ions in the cooling water.

• Journal of the Korea Safety Management & Science
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• v.11 no.1
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• pp.1-6
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• 2009

The specific feature of trains as a means of transportation is that, on one side, at once they can carry big loads but, at the same time, if an accident occurs, it potentially leads to many human casualties or big material losses. Especially, train accidents caused by bad weather conditions result in many fatal losses of human lives and property. In Korea many railways run either in mountainous areas or along rivers thus making them especially susceptible to natural hazards. The types of damages inflicted by heavy rains resulting from rapidly changing meteorological conditions are diverse; and not only their scope is big but also they repeat regularly. Consequently, this study analyses the reasons why such effects of heavy rains on the railway conditions, damage to the railways caused by heavy rains or cases of stone fall as well as other types of accidents are not avoided. Study also, on the basis of laws related to movement in poor weather conditions and specifics of train braking, identifies systematic and technical problems and suggests and emphasizes new complex measures on their prevention.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.4
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• pp.753-763
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• 2014

Recently financial institutions and large retailers have a large amount of personal information leakage accident occurred one after another, and the damage is a trend of increasing day by day. Regulation such as enforcing the encryption of the personal identification information are strengthened. Efficient technology to encrypt personal information is Format-preserving encryption. Typical encryption expand output data length than input data length and change a format. Format Preserving Encryption is an efficient method to minimize database and application modification, because it makes preserve length and format of input data. In this paper, to encrypt personal information efficiently, we propose newly Format Preserving Encryption using Block cipher mode of operation.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.10a
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• pp.103-114
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• 2003

This paper aims to propose a method that helps maintenance engineers to evaluate the damage states of bridge structure systems by using a Fuzzy Fault Tree Analysis. It may be stated that Fuzzy Fault Tree Analysis may be very useful for the systematic and rational fuzzy reliability assessment for real bridge structure systems problems because the approach is able to effectively deal with all the related bridge structural element damages in terms of the linguistic variables that incorporate systematically experts experiences and subjective judgement. This paper considers these uncertainties by providing a fuzzy reliability-based framework and shows that the identification of the optimum maintenance scenario is a straightforward process. This is achieved by using a computer program for LIFETIME. This program can consider the effects of various types of actions on the fuzzy reliability index profile of a deteriorating structures. Only the effect of maintenance interventions is considered in this study. However. any environmental or mechanical action affecting the fuzzy reliability index profile can be considered in LIFETIME. Numerical examples of deteriorating bridges are presented to illustrate the capability of the proposed approach. Further development and implementation of this approach are recommended for future research.

• Smart Structures and Systems
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• v.21 no.2
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• pp.195-205
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• 2018

Research on Lamb wave-based damage identification in plate-like structures depends on precise knowledge of dispersive wave velocity. However, boundary reflections with the same frequency of interest and greater amplitude contaminate direct waves and thus compromise measurement of Lamb wave dispersion in different materials. In this study, non-reflecting boundaries were proposed in both numerical and experimental cases to facilitate time-frequency characterization of Lamb wave dispersion. First, the Lamb wave equations in isotropic and laminated materials were analytically solved. Second, the non-reflecting boundaries were used as a series of frames with gradually increased damping coefficients in finite element models to absorb waves at boundaries while avoiding wave reflections due to abrupt property changes of each frame. Third, damping clay was sealed at plate edges to reduce the boundary reflection in experimental test. Finally, the direct waves were subjected to the slant-stack and short-time Fourier transformations to calculate the dispersion curves of phase and group velocities, respectively. Both the numerical and experimental results suggest that the boundary reflections are effectively alleviated, and the dispersion curves generated by the time-frequency analysis are consistent with the analytical solutions, demonstrating that the combination of non-reflecting boundary and time-frequency analysis is a feasible and reliable scheme for characterizing Lamb wave dispersion in plate-like structures.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.5 no.4
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• pp.72-78
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• 2006

Inherent in machine tool structures are the vibrations which are generated by rotating parts such as motors, spindles and chucks. The vibrations not only hurt the precision machining but also damage the structures, and become more serious with time. Many of the old machine tools show severe vibrations for the desired accuracy of the modern industries. It is too much of a waste, however, to get rid of them as scraps. There have been many researches in order to suppress the vibrations of old machine tool structures using the tool post which utilizes actuators to compensate the existing vibrations and using the dampers or absorbers attached to some critical parts. In this paper, the dynamic properties are analyzed to obtain the natural frequencies and mode shapes of a machine tool structure which reflect the main reasons of the biggest vibrations under the given operating conditions. And the feasibility of improving the stability of the structure has been investigated with minor design changes and expenses. The result of the study shows that simple changes based on proper system identification can considerably improve the stability of the machine tool structure.

• Molecular & Cellular Toxicology
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• v.2 no.1
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• pp.60-66
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• 2006

Methylmercury (MeHg), one of the heavy metal compounds, can cause severe damage to the central nervous system in humans. Many reports have shown that MeHg is poisonous to human body through contaminated foods and has released into the environment. Despite many studies on the pathogenesis of MeHg-induced central neuropathy, no useful mechanism of toxicity has been established so far. This study, using of suppression subtractive hybridization (SSH) method, was peformed to identify differentially expressed genes by MeHg in SH-SY5Y human neuroblastoma cell line. We prepared to total RNA from SH-SY5Y cells treated with solvent (DMSO) and $6.25\;{\mu}M\;(IC_{50})$ MeHg and performed forward and reverse SSH. Differentially expressed cDNA clones were screened by dot blot, sequenced and confirmed that individual clones indeed represent differentially expressed genes with real time RT-PCR. These sequences were identified by BLAST homology search to known genes or expressed sequence tags (ESTs). Analysis of these sequences may provide an insight into the biological effects of MeHg in the pathogenesis of neurodegenerative disease and a possibility to develop more efficient and exact monitoring system of heavy metals as ubiquitous environmental pollutants.

• Korean Journal of Pharmacognosy
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• v.29 no.1
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• pp.1-7
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• 1998

Aqueous extract of Morus alba L. blocked the toxic effect of paraquat on E. coli growth. The active components in the extract may be capable of crossing the cell membranes and protect against superoxide toxicity in E. coli, The extract inhibited $FeSO_4/H_2O_2$ induced lipid peroxidation in rat liver homogenate and protected against t-butyl hydroperoxide caused Ac2F cell damage. Moreover, the extract showed inhibitory effect on phospholipase $A_2$ activity in a dose dependent manner. Antiinflammatory effect of the extract was further investigated using the carrageenin-induced oedema model. A single adminstration of the extract (3g/kg body, p.o.) was more effective than indomethacin. These results suggest that the isolation and identification of the active components would have significant therapeutic application to inflammation associated with oxygen radicals.