• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.704-710
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• 2017

Our research team is developing a 6-DOF manipulator that is adequate for the narrow workspace of press forming processes. This paper addresses the task sequence optimization methods for the manipulator to minimize the task-finishing time. First, a kinematic model of the manipulator is presented, and the anticipated times for moving among the task locations are computed. Then, a mathematical model of the task sequence optimization problem is presented, followed by a comparison of three meta-heuristic methods to solve the optimization problem: an ant colony system, simulated annealing, and a genetic algorithm. The simulation shows that the genetic algorithm is robust to the parameter settings and has the best performance in both minimizing the task-finishing time and the computing time compared to the other methods. Finally, the algorithms were implemented and validated through a simulation using Mathworks' Matlab and Coppelia Robotics' V-REP (virtual robot experimentation platform).

• Research in Plant Disease
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• v.13 no.1
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• pp.24-29
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• 2007

A total of 35 strains of Ralstonia solanacearum isolated from wilted pepper and tomato plants in Korea were analyzed for their genetic diversity by bacteriological, pathological and molecular biological approaches. All the strains were identified as R. solanacearum biovar 4 on the basis of physiological and biochemical tests, and species-specific PCR primers. Pathogenicity of the strains was confirmed by inoculating on 4-week-old pepper and tomato seedlings. Using cluster analysis based on repetitive sequence-based polymerase chain reaction (rep-PCR) genomic fingerprints, R. solanacearum strains isolated from pepper and tomato in Korea divided into 6 groups showing a high degree of genetic diversity at 55% similarity level. The genetic diversify of strains was not significantly correlated with their geographic origins and host plants.

• YAKHAK HOEJI
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• v.57 no.2
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• pp.132-138
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• 2013

Acinetobacter baumannii is gram-negative bacilli that can be widely found in environments. Recently, A. baumannii emerged as a serious nosocomial infection. A total of 92 A. baumannii were isolated from hospitalized patients in Seoul, Korea, between December 2010 and April 2011. Antimicrobial susceptibility testing was investigated using CLSI agar dilution methods. Tigecycline non-susceptible A. baumannii isolates were investigated by repetitive extragenic palindromic sequence-based PCR (rep-PCR). Pulsed-field gel electrophoresis was performed to determine the epidemiological relationships. All clinical isolates showed high-level resistance to the most commonly used antibiotics: Ciprofloxacin (87.0%), Ampicillin/sulbactam (82.6%), Cefotaxime (81.5%), Ceftazidime (80.4%). Moreover, 50.0% of these isolates were non-susceptible to tigecycline. When evaluated by RAPD analysis, generated distinct band ranging in size from 1kb to 8k band varying from 4 to 10 bands. Stricter surveillance and more rapid detection are essential to prevent the spread of multi drug resistant A. baumannii.

• The Journal of the Korea Contents Association
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• v.12 no.8
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• pp.123-135
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• 2012

As contents go digital and networks go broadband, there are a lot of changes made to Ad market caused by multimedia and multichannel environment. While platforms as the contents distribution window are increasing, the reality is that additional Ad revenue through platforms is concentrated on mammoth exclusive media because there are small number of the media that has control over platforms is able to create production and provide capital. In addition, as Media rep laws is passed at the Assembly plenary session, tipping effect in Ad market concentrated to some media. In this reality, pay TV market is expected to be within its direct orbit as it is predicted to produce new contents and distribution growth thanks to a wide variety of genres and experimental challenge. Thus, this study is to propose the methodology and an alternative for pay Ad market expansion. As the result of this research, an improvement scheme of indirect advertisement, virtual advertisement, and prohibited advertising item is suggested, and methodology for advertising market expansion is suggested through enterprise and government.

• Journal of Microbiology and Biotechnology
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• v.26 no.8
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• pp.1481-1489
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• 2016

The emergence and dissemination of carbapenemase-producing Acinetobacter baumannii isolates have been reported worldwide, and A. baumannii isolates harboring bla_OXA-23 are often resistant to various antimicrobial agents. Antimicrobial resistance can be particularly strong for biofilm-forming A. baumannii isolates. We investigated the genetic basis for carbapenem resistance and biofilm-forming ability of multidrug-resistant (MDR) clinical isolates. Ninety-two MDR A. baumannii isolates were collected from one university hospital located in the Chungcheong area of Korea over a 5-year period. Multiplex PCR and DNA sequencing were performed to characterize carbapenemase and bap genes. Clonal characteristics were analyzed using REP-PCR. In addition, imaging and quantification of biofilms were performed using a crystal violet assay. All 92 MDR A. baumannii isolates involved in our study contained the bla_OXA-23 and bap genes. The average absorbance of biomass in Bap-producing strains was much greater than that in non-Bap-producing strains. In our study, only three REP-PCR types were found, and the isolates showing type A or type B were found more than 60 times among unique patients during the 5 years of surveillance. These results suggest that the isolates have persisted and colonized for 5 years, and biofilm formation ability has been responsible for their persistence and colonization.

• Journal of Korean Society of Forest Science
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• v.98 no.2
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• pp.163-169
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• 2009

This study examines the relationships between visitors' environmental attitudes as measured by the new environmental paradigm (NEP) and their recreational motivations based on data collected from a national park in South Korea. The data analysis indicated that visitors' environmental attitudes and motivation were multi-dimensional structures. The NEP composed of three factors named 'Humans over Nature', 'Balance of Nature', and Limit to Growth'. Visitors' motivation also composed of four factors representing 'Achievement and Stimulation', 'Escape and Enjoying Nature', 'Social and Leadership', and 'Family'. However, there were significant correlations among the factors, suggesting they were independent each other. There were also significant differences in visitors' motivation due to their level of environmental attitudes.

• Proceedings of the Korea Contents Association Conference
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• 2003.05a
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• pp.393-398
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• 2003

Video which contains the multiple data such as text, images, audio and motion of objects is typical multimedia data. Multimedia retrieval system using XML is essential for efficient rep. of multimedia data. Therefore, multimedia retrieval system for retrieval and structural understanding is needed to retrieve the multimedia data. This Paper Proposes the multimedia retrieval system based on XML Meta-data modeling techniques.

• Journal of Applied Biological Chemistry
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• v.59 no.1
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• pp.63-68
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• 2016

This study was performed to assess the microbiological quality of Brassica campestris var. narinosa microgreen from harvesting and processing steps. The samples were analyzed for total viable cell counts (TVC), coliforms, Enterobacteriaceae, Escherichia coli, Salmonella spp., Listeria monocytogenes, Vibrio parahaemolyticus, Bacillus cereus, and Staphylococcus aureus. The total viable counts of microgreen (whole leaves) and environment samples from harvesting steps were higher than 6.8 log CFU/g and the contamination level of coliforms in the samples were 3.2 log CFU/g and 3.5 log CFU/g of microgreen and soil, respectively. In case of microgreen samples collected from processing steps, the contamination level of TVC and coliforms were higher in raw materials than samples obtained from later stages of processing, i.e. washing, drain, and final products. The contamination levels of B. cereus in raw materials and environments decreased approximately 1.4 log CFU/g in final products. S. aureus was detected in soil samples but Salmonella spp., Listeria monocytogenes, Vibrio parahaemolyticus and pathogenic E. coli was not detected. In order to identify the sources of contamination for microgreen, the genetic similarity of B. cereus isolates obtained from harvesting and processing steps were compared using the repetitive-sequence-based polymerase chain reaction method. B. cereus isolates obtained from harvesting environments and microgreen were clustered with a similarity greater than 95%. In case of B. cereus isolates obtained from microgreen and environmental samples at processing steps showed low genetic similarity.

• The Journal of the Korean Society for Microbiology
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• v.35 no.5_6
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• pp.349-349
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• 2000

• Korea-Australia Rheology Journal
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• v.18 no.2
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• pp.41-49
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• 2006

A modified Volume-of-Fluid (VOF) numerical method is used to predict the dynamics of a liquid drop of a low viscosity dilute polymer solution, forming in air from a circular nozzle. Viscoelastic effects are rep-resented using an Oldroyd-B model. Predicted drop shapes are compared with experimental observations. The main features, including the timing of the shape evolution and the 'bead-on-a-string' effect, are well reproduced by the simulations. The results confirm published conclusions of the third author, that the deformation is effectively Newtonian until near the time of Newtonian pinch-off and that the elastic stress becomes large in the pinch region due to the higher extensional flow there.