• Korean Journal of Clinical Laboratory Science
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• v.50 no.2
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• pp.100-109
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• 2018

The emergence and dissemination of multidrug-resistant (MDR) Acinetobacter baumannii isolates have been reported worldwide, with most of these possessing the ability to form biofilms. Biofilm formation is an important virulence factor associated with the resistance to disinfection and desiccation. This study examined the genetic basis of antimicrobial resistance mechanisms of biofilm-forming A. baumannii clinical isolates. Imaging and quantification of biofilms were performed by a crystal violet assay and 46 biofilm-forming A. baumannii isolates were selected. Subsequently, 16 isolates belonging to different clones were identified using REP-PCR, and detection of the antimicrobial determinants in the isolates was carried out. The 16 isolates included 9 non-MDR and 7 MDR isolates. The mean biomass $OD_{560}$ values of the non-MDR (0.96) and MDR (1.05) isolates differed but this difference was not significant. In this study, most biofilm-forming MDR A. baumannii isolates contained various antimicrobial resistance determinants ($bla_{OXA-23}$, armA, and mutations of gyrA and parC). On the other hand, most biofilm-forming non-MDR A. baumannii isolates did not contain antimicrobial resistance determinants. These results suggest that there is little correlation between the biofilm-forming ability and antimicrobial susceptibility in A. baumannii isolates. In addition, the emergence of MDR A. baumannii clinical isolates is generally caused by mutations of the genes associated with antimicrobial resistance and/or the acquisition of various antimicrobial resistance determinants.

• Journal of Food Hygiene and Safety
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• v.25 no.4
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• pp.346-353
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• 2010

This study was conducted to determine cleaning effects of environmental-friendly washing detergent on milking installation in dairy farms. Milking machine, cooling machine and milking liner were washed by alkaline detergent and acid detergent for first three weeks and alkaline detergent and environmental~friendly detergent for next three weeks and the results get through microorganism and physico-chemistry analysis at the five district dairy farms different from environment. E-coli, coliform, fecal coliform, staphylococcus aureus, fecal streptococcus, prsudomonas aeruginosa and yersinia were not found in all of the dairy farms, and total colony counts were no difference compared with chemical detergent. The water for washing exceeded the determining acceptable level of nitrate nitrogen in the Anseong, Onyang and Cheonan and the remaining substance of washed water was also high levels. The cause of the result was that the level of nitrate nitrogen of water is basically high. Therefore, this study indicated that washing effect is no differences between environmental-friendly detergent and chemical detergent by washing for milking machine and cooling machine. Above all, producing high quality milk is to manage the water quality as well as using detergent.

• Journal of the Korean Geotechnical Society
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• v.15 no.3
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• pp.131-149
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• 1999

It was found that surface roughness has a first-order effect on the interface shear strength and accordingly it should be accurately quantified if its role is to be properly understood. To quantify the surface topography, first of all, a variety of commonly used surface roughness parameters and profiling methods were reviewed in this study. Based on this review, the normalized roughness parameter. $R_n$(Uesugi and Kishida, 1986), the profile roughness parameter, $R_L$, and the surface roughness parameter, $R_n$(Dove and Frost, 1996), were selected to be appropriate candidates of roughness parameters and the digital image analysis based Optical Profile Microscopy(OPM) method(Dove and Frost, 1996) to be an appropriate profiling method for this study. Using a smooth and three textured HDPE geomembranes which encompass the range of textures and texture patterns commonly used, a series of roughness measurements on virgin and previously used geomembranes were performed. The results showed that both $R_L\; and\; R_S$ values appropriately reflect the degree of texturing for the geomembranes used in this study, however, $R_n$ value showed limited ranges of variation which may not be sufficient to permit distinction between roughness values for certain conditions. The results of this study will be extended to the investigation of the influence of surface roughness on interface strength in future study.

• Korean Journal of Construction Engineering and Management
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• v.14 no.2
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• pp.96-107
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• 2013

Tower crane hoisting plan is one of the key element for the success of entire High-Rise Building construction. Hoisting time is the basic factor to appropriate hoisting plan which need to the hoisting load estimate and tower crane selection. With this reason, accurate hoisting time is needed to the proper hoisting plan. The current hoisting time estimation for High-Rise Building focus on the hoisting cycle time estimation with historical data. However, this method underestimated the external influences like environmental factor. Thus, this paper aims to develop the hoisting time estimation model with discrete event simulation which include the wind influences with certain height. According to the simulation result, the hoisting time which applied wind influence is increasing with height growth. Because of the high speed wind, the upper area of building has more operation delay time than the mechanical operation time. Seoul, the research area, has the most fastest wind speed on April and the least on October. Due to these differences of wind speed, the hoisting time is estimated with significant differences between April and October. This hosting time estimation model would be used for estimating the influence of wind. Moreover, this could apply to make the realistic hoisting plan.

• Journal of Digital Convergence
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• v.15 no.7
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• pp.169-180
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• 2017

China's mobile communication market has been growing quantitatively and qualitatively since 2000. Currently, it has secured 1.27 billion mobile subscribers and many of the Korean companies try to enter the Chinese market and cooperation with companies in China is being held. Thus understanding of the Chinese markets is the key to better prepare for future international competition. This study is to identify factors affecting switching intentions and behaviors for Chinese mobile subscribers to other mobile service providers by the PPM and it is to derive correlations between strategies of mobile service providers and users' switching intention by the groups classified by ARPU. We conducted a survey targeting 270 Chinese mobile users and analyze it by using Smart PLS 2.0. In conclusion, push effects have positive influence on intention to switching and relational switching cost among mooring effect have significantly negative influence on intention to switching In particular, intention to switching depending on the groups classified by a level of their ARPU have been shown as significantly different. This study will extend theoretical range of PPM theory in explaining users' switching behaviors and contribute to establish strategies to enter the chinese market.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.2
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• pp.113-119
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• 2015

The measurement of hydration level in the surface layer of the skin, stratum corneum (SC), gives important information on the biophysical properties and function of the skin barrier such as softness, flexibility, and healthiness of the skin. But it is difficult to measure a consistent hydration level from a sample to another sample due to individual variations and environmental changes. The aim of this study was to evaluate objective hydration after using various products in the SC. The SC Hydration was measured by capacitance (Corneometer$^{(R)}$, C+K, Germany) on the ventral site of forearm from 40 healthy volunteers. The skin surface was chronologically measured immediately after application of the test products and 3 and 6 hours later. We analyzed the averages of five measurements of each site and used the hydration increase rate for correction on untreated site variation. We found that most polyols including glycerol and butylenes glycol influenced directly the hydration increase rate in the SC previously. In this study, glycerol was used to prepare the standard products from 0 to 20 percents and applied to the same volunteers. The individual standard curve showed linear relation to glycerol concentrations. Based on the the standard curve, hydration of SC was converted into hydration increase rate to glycerol concentrations. The converted glycerol concentrations of products were repetitive and reproducible. In addition, the individual standard curve was used to relate the skin type of each individual. These results suggest that the hydration of the SC standardized regardless of external variation and individual skin condition can explain detailed skin state variation. Further studies will be conducted with other ingredients such as surfactants, lipids and aqueous materials, and with other methods for noninvasive measurement.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.12
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• pp.704-715
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• 2004

Recently, a single or multi processor system uses the hierarchical memory structure to reduce the time gap between processor clock rate and memory access time. A cache memory system includes especially two or three levels of caches to reduce this time gap. Moreover, one of the most important things In the hierarchical memory system is the hit rate in level 1 cache, because level 1 cache interfaces directly with the processor. Therefore, the high hit rate in level 1 cache is critical for system performance. A victim cache, another high level cache, is also important to assist level 1 cache by reducing the conflict miss in high level cache. In this paper, we propose the advanced high level cache management scheme based on the processor reuse information. This technique is a kind of cache replacement policy which uses the frequency of processor's memory accesses and makes the higher frequency address of the cache location reside longer in cache than the lower one. With this scheme, we simulate our policy using Augmint, the event-driven simulator, and analyze the simulation results. The simulation results show that the modified processor reuse information scheme(LIVMR) outperforms the level 1 with the simple victim cache(LIV), 6.7% in maximum and 0.5% in average, and performance benefits become larger as the number of processors increases.

• Journal of Wetlands Research
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• v.20 no.3
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• pp.256-262
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• 2018

Multiple temporal scale can be a useful method to understand population dynamics in ecosystem. The multi-temporal scale approach for population dynamics has rarely been researched till lately. This study was carried out to identify the factors in affecting the population dynamics of herons, including Eastern Cattle Egret (Bubulcus coromadus), Grey Heron (Ardea cinerea), Great Egret (A. alba), Intermediate Egret (Egretta intermedia) and Little Egret (E. garzetta), at rice paddy fields of Seokmun-myeon in the city of Dangjin, South Chungcheong Province during the main breeding periods from 2014 to 2017. We identified the population dynamics of herons at different time interval (day and month) using the unmanned monitoring system. As a result, monthly population dynamics was mostly affected by time, mean temperature and mean precipitation, whereas daily population dynamics was affected by mean temperature and habitat types. The results suggest that there are differences in the factors affecting the population dynamics of herons according to the time scale.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.6
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• pp.371-377
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• 2004

Sulfate adsorption in forest soils is a process of sulfur dynamics playing an important role in plant uptake, cation movement, acid neutralization capacity and so on. The relationship between sulfate adsorption and some physicochemical properties of four forest soils was investigated. Extractable sulfate contents and sulfate adsorption capacity (SAC) in the forest soils varied much among study sites. Extractable sulfate contents were more in sub-surface soils with lower organic matter and greater Al and Fe oxides than in surface soils. The average contents of $Al_d$ and $Fe_d$ in the sub-surface soils were 8.49 and $12.45g\;kg^{-1}$, respectively. Soil pH, cation exchange capacity and clay content were positively correlated with the extractable sulfate contents and SAC. Organic carbon content, however, was negatively correlated with the extractable sulfate contents, implying the competitive adsorption of sulfate with soil organic matter. Considerably significant correlation was found between inorganic + amorphous Al and Fe oxides and the sulfate adsorption, but crystalline Al and other fractions of Fe oxide showed no correlation. Relatively close relationship between the adsorbed sulfates and soil pH, cation exchange capacity, or amorphous Al oxides indicates that the accelerated soil acidification may substantially reduce the potential for sulfate adsorption contributing to sulfur flux in forest ecosystems.

• Fire Science and Engineering
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• v.25 no.2
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• pp.9-22
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• 2011

Some Volunteer Fire-Fighting Teams (VFFTs) play an important role in Civilian Volunteer Disaster Prevention by being managed effectively, but the others do not. There can be many cause-analyses about this difference. VFFTs aren't a profit-making organization and are a group which has no compulsion. So it is important that who the leader is, and what type of leadership he has. Furthermore VFFTs have hierarchy like fire-fighting teams and so the leader's command and judgement bring about the actual distinction in the organizational operation. Under this background, the survey has been carried out on the trust of leader and leadership type which may maximize the organization commitment. Consequently, to make efficiency of District Disaster & Volunteer Aid Network increase by augmenting organization commitment. The leader of VFFTs should get the transformational leadership rather than transactional leadership and have paternal or democratic leadership in the decision-making process. Especially we have to create a traditional and unique korean Volunteer fire-fighting organization culture through paternal leadership. Additionally, the trust on leaders should be recognized as a fundamental factor to obtain more performances beyond expectation by increasing the success and output of the team, mutual understanding and cooperation.