• Geophysics and Geophysical Exploration
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• v.11 no.2
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• pp.153-160
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• 2008

Seismic modeling is used to simulate wave propagation in the earth. Although the earth's subsurface is usually semi-infinite, we cannot handle the semi-infinite model in seismic modeling because of limited computational resources. For this reason, we usually assume a finite-sized model in seismic modeling. In that case, we need to eliminate the edge reflections arising from the artificial boundaries introducing a proper boundary condition. In this study, we changed three kinds of boundary conditions (sponge boundary condition, Clayton and Engquist's absorbing boundary condition, and Higdon's transparent boundary condition) so that they can be applied in elastic wave modeling for anisotropic media. We then apply them to several models whose Poisson's ratios are different. Clayton and Engquist's absorbing boundary condition is unstable in both isotropic and anisotropic media, when Poisson's ratio is large. This indicates that the absorbing boundary condition can be applied in anisotropic media restrictively. Although the sponge boundary condition yields good results for both isotropic and anisotropic media, it requires too much computational memory and time. On the other hand, Higdon's transparent boundary condition is not only inexpensive, but also reduce reflections over a wide range of incident angles. We think that Higdon's transparent boundary condition can be a method of choice for anisotropic media, where Poisson's ratio is large.

• Journal of Science and Technology Studies
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• v.12 no.1
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• pp.107-144
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• 2012

Recently concerns on the energy future are rising in Korea after nuclear disaster of Fukushima in Japan last year. However, even after Fukushima disaster Korean government keeps on insisting nuclear oriented energy policy. Contrary to it, some of civil society's organizations(CSOs) including environment groups and progressive political parties are making strong voices for phase-out nuclear. As a way of phase-out nuclear activity researcher groups based on CSOs have presented several alternative energy scenarios against the official government scenario so that contest between the two senarios seems not to be avoided. This article aims to analyse the politics of expertise around energy scenarios in Korea by highlighting differences between two scenarios of government and CSOs in terms of epistemological and methodological base, value orientation, institutional foundation, and the socio-political contexts of scenarios. Our research shows that government's energy scenario is based on scientific-positivist epistemology, firm belief in value neutrality and forecasting method, and is built by neo-classical economists at government-sponsored research institutes in accordance with the 'Business As Usual' approach. In contrast, alternative scenarios of CSOs can be said to be based on epistemological constructivism, value oriented attitudes and backcasting method, and be built by collaboration of researchers and activists with different academic and social backgrounds after Fukushima nuclear disaster.

• Journal of the Korean Geotechnical Society
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• v.33 no.7
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• pp.55-64
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• 2017

A geological repository has been considered one of the most adequate options for the disposal of high-level radioactive waste. A geological repository will be constructed in a host rock at a depth of 500~1,000 meters below the ground surface. The geological repository system consists of a disposal canister with packed spent fuel, buffer material, backfill material, and intact rock. The buffer is very important to assure the disposal safety of high-level radioactive waste. It can restrain the release of radionuclide and protect the canister from the inflow of groundwater. High temperature in a disposal canister is released into the surrounding buffer material, and thus the thermal transfer behavior of the buffer material is very important to analyze the entire disposal safety. Therefore, this paper presents a thermal conductivity prediction model for the Kyungju compacted bentonite buffer material which is the only bentonite produced in Korea. Thermal conductivity of Kyungju bentonite was measured using a hot wire method according to various water contents and dry densities. With 39 data obtained by the hot wire method, a regression model to predict the thermal conductivity of Kyungju bentonite was suggested.

• Journal of the Society of Disaster Information
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• v.10 no.2
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• pp.288-293
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• 2014

The purpose of this study was to provide response plans against acts of suicide bomb using utilize unmanned aircrafts to prevent large losses of lives such as the terrorist attacks of September 11. As the result, First, this research suggests revising the definition and categorization of utilizing unmanned aircrafts and legislating the Anti-terrorism law. Second, it is needed to establish the proper social safety network through terrorism response management integrated system against the terror of related organization. Third, suicide bomb using utilizing unmanned aircrafts can be occurred because it is possible to make bomb and open web site for terrorism without connection with terrorist organization because of universal use of Internet. In response to this, it is needed to make a law which can block the use and open of illegal site and contents. Forth, the increasing number of foreigners and immigrants can make conflicts, and cause the foreigner's anti-korea feeling and the citizen's anti-cultural diffusion. Therefore, it is needed for the citizen to change and improve the awareness of them, and the change of social politics.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.334-344
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• 2018

This study was conducted to identify the relationship between knowledge, attitude, and compliance regarding infection preventive behaviors among long-term care hospital staff during a Middle East Respiratory Syndrome (MERS) epidemic. The subjects were 211 staff members of a long-term care hospital in J province evaluated using a structured survey. Data were collected between June 15 and July 15, 2015 and analyzed using SPSS/WIN 24.0 based on an independent t-test, ANOVA, and Welch test, while post-hoc tests were conducted using the Scheffe test and the Grames-Hawell test. The MERS knowledge score of the staff at the long-term care hospital was high for nurses and nurse aids, who had experienced infection management when they received influenza vaccine in the previous year and were provided with easy access to hand sanitizers. Attitude towards MERS was more positive for nurses than nurse aids and caregivers. The degree of execution of infection preventive behaviors in terms of daily activity was high when influenza shots were received in the prior year; in terms of caring for patients, it was high when influenza shots were received in the previous year and they had easy access to hand sanitizers. The relationship between knowledge, attitude, and infection preventive behavior regarding MERS was such that high knowledge and positive attitude led to a higher degree of execution of infection preventive behavior. Therefore, during periods of high prevalence of newly infectious diseases such as MERS, it is important for the long-term care hospitals to conduct infection management education including the characteristics of the MERS disease, its transmission, and its prevention to enhance knowledge regarding MERS and induce positive change in attitude to improve the level of infection preventive behaviors.

• The KIPS Transactions:PartD
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• v.13D no.5 s.108
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• pp.641-650
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• 2006

XML has the characteristics of self-describing and uses DTD or XML schema in order to constraint its structure. Even though the XML schema is only at the stage of recommendation yet, it will be prevalently used because DTD is not itself XML and has the limitation on the expression power. The structure defined by the XML schema as well as the data of the XML documents can vary due to complex reasons. Those reasons are errors in the XML schema design, new requirements due to new applications, etc. Thus, we propose XML schema evolution operators that are extracted from the analysis of the XML schema updates. These schema evolution operators enable the XML schema updates that would have been impossible without supporting tools if there are a large number of XML documents complying the U schema. In addition, these operators includes the function of automatically finding the update place in the XML documents which are registered to the XSE system, and maintaining the XML documents valid to the XML schema rather than merely well-formed. This paper is the first attempt to update XML schemas of the XML documents and provides the comprehensive set of schema updating operations. Our work is necessary for the XML application development and maintenance in that it helps to update the structure of the XML documents as well as the data in the easy and precise manner.

• Korean Journal of Microbiology
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• v.54 no.1
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• pp.53-59
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• 2018

The objective of this study was to investigate the plasmid profiling of multi-drug resistant (MDR) Vibrio in influent (inflow) and effluent (discharged) water samples of fish farms in Jeju, South Korea. MDR isolates identified through disc diffusion susceptibility tests, were subjected to plasmid profiling. One hundred fifty Vibrio isolates were obtained from each influent and effluent water sample. All MDR isolates were subjected to plasmid profiling. Greater number of bacteria were enumerated from effluents (61%) comparing to influents (39%). High incidence of neomycin, sulfamethoxazole, amoxicillin and oxytetracycline resistance was observed among the isolates, which was higher in effluent samples. In contrast, Vibrio isolates were more susceptible to florfenicol, chloramphenicol, ciprofloxacin, and nalidixic acid. Among 99 (influent 39 and effluent 60) MDR isolates, a total of 58 (influent 38 and effluent 20) were found to bear plasmids ranging from 1.7 kb to >10 kb and showed 19 different antibiograms according to the size of plasmids. MDR isolates showed six and four distinct plasmid profiles in influent and effluent, respectively. Effluent samples contained more plasmid-carrying MDR Vibrio isolates with more diverse plasmid profiles and antibiograms, suggesting that fish farm tanks may serve as a reservoir of antibiotic resistance genes. The presence of plasmid-carrying MDR Vibrio isolates in fish farm effluent water may contribute to the dissemination of antibiotic resistance genes to the environments, which ultimately poses threat to human health.

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.1
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• pp.80-90
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• 2001

The aim of this study is to develop the methodology which enables to identify the mechanical properties of element such as stress intensity factor by using the AE parameters. Considering the multivariate and nonlinear properties of AE parameters such as ringdown count, rise time, energy, event duration and peak amplitude from fatigue cracks of machine element the principal component regression(PCR) and artificial neural network(ANN) models for the estimation of stress intensity factor were developed and validated. The AE parameters were found to be very significant to estimate the stress intensity factor. Since the statistical values including correlation coefficients, standard mr of calibration, standard error of prediction and bias were stable, the PCR and ANN models for stress intensity factor were very robust. The performance of ANN model for unknown data of stress intensity factor was better than that of PCR model.

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.3
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• pp.227-236
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• 2003

Leaks in underground pipelines can cause social, environmental and economical problems. One of relevant countermeasures against leaks is to find and repair of leak points of the pipes. Leak noise is a good source to identify the location of leak points of the pipelines. Although there have been several methods to detect the leak location with leak noise, such as listening rods, hydrophones or ground microphones, they have not been so efficient tools. In this paper, acoustic emission (AE) sensors and accelermeters are used to detect leak locations which could provide all easier and move efficient method. Filtering, signal processing and algorithm of raw input data from sensors for the detection of leak location are described. A 120m-long pipeline system for experiment is installed and the results with the system show that the algorithm with the AE sensors and accelerometers offers accurate pinpointing of leaks. Theoretical analysis of sound wave propagation speed of water in underground pipes, which is critically important in leak locating, is also described.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.4
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• pp.428-435
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• 2019

The rapid increase and dissemination of carbapene mases, such as Klebsiella pneumoniae carbapenemase (KPC), has become a major problem within the field of healthcare-related infection. There are few antibiotics to treat carbapenem-resistant Enterobacteriaceae (CRE) infections, so the identification of resistant bacterial mechanisms is critical to initiate infection control and conduct epidemiological research. A rapid and effective method for detecting KPC-producing bacteria is needed to avoid therapeutic failures and introduce measures to prevent and control the dissemination of these multi-resistant bacteria. During the study period, 31 isolates (seven isolates of Acinetobacter spp., six isolates of Morganella morganii, five isolates of Pseudomonas aeruginosa, five isolates of Proteus mirabilis, one isolate of Proteus vulgaris, two isolates of Enterobacter cloacae, one isolate of Enterobacter aerogenes, one isolate of Klebsiella pneumoniae, one isolate of Klebsiella oxytoca, one isolate of Serratia marcescens and one isolate of Escherichia coli) were identified by the VITEK. Gram negative rod bacteria were the most frequently isolated from urine (35.5%), blood (19.4%), sputum (16.1%), pus (9.7%), ascitic fluid (9.7%), tracheal aspirates (6.5%) and bile juice (3.2%). Analysis using the PCR method identified the bla_KPC gene in the K. oxytoca1 strain, but the bla_IMP, bla_VIM and bla_OXA-48 genes are not amplified. In conclusion, diagnosis using the PCR method can accurately and quickly diagnose KPC, thus establishing quick preventive measures to prevent the spread of KPC in hospitals.