• Journal of Powder Materials
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• v.22 no.3
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• pp.181-186
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• 2015

In this study, the effect of the friction stir welding (FSW) was compared with that of the gas tungsten arc welding (GTAW) on the microstructure and microhardness of Cu-Ni alloy weldment. The weldment of 10 mm thickness was fabricated by FSW and GTAW, respectively. Both weldments were compared with each other by optical microstructure, microhardness test and grain size measurement. Results of this study suggest that the microhardness decreased from the base metal (BM) to the heat affected zone (HAZ) and increased at fusion zone (FZ) of GTAW and stir zone (SZ) of FSW. the minimum Hv value of both weldment was obtained at HAZ, respectively, which represents the softening zone, whereas Hv value of FSW weldment was little higher than that of GTAW weldment. These phenomena can be explained by the grain size difference between HAZs of each weldment. Grain size was increased at the HAZ during FSW and GTAW. Because FSW is a solid-state joining process obtaining the lower heat-input generated by rotating shoulder than heat generated in the arc of GTAW.

• Journal of Korean Neurosurgical Society
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• v.41 no.5
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• pp.306-313
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• 2007

Objective : In permanent distal middle cerebral artery occlusion [pdMCAO] model of rats, the temporal order of subcellular translocation is not fully understood yet. We studied translocation sequence of cytochrome c and apoptosis inducing factor [AIF] after pdMCAO and patterns of expression. Methods : Twenty-one male rats - with ten minutes, 1, 4, 8, 24 and 48 hours of pdMCAO groups - were enrolled. At core and penumbra area of each cerebral cortex, Western blotting of cytochrome c and AIF were performed using cytosolic fractions and then compared with sham specimens. With 48 hours group, the expression of cytochrome c and AIF was examined with immunofluorescent staining. Results : Compared to sham, the cytosolic translocation of cytochrome c significantly increased at all time points [p<0.05]. As early as 10 min after onset of ischemia, it was increased significantly [p<0.01]. The cytosolic translocation of AIF showed gradual increase with the passage of time and significantly increased 8 hours after [p<0.05]. As late as 24 hours and 48 hours after onset of ischemia, there were increased most significantly [p<0.01]. At penumbra, both proteins failed to show significant increase at all time points. At 48 hours after ischemia, colocalization of cytochrome c and AIF were confirmed. Conclusion : Cytosolic translocation of cytochrome c peaks much earlier than that of AIF in pdMCAO model of rat. Caspase dependent apoptosis activates soon after ischemia and later, it can be reinforced by gradually increasing AIF in ischemic core.

• Korean Journal of Remote Sensing
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• v.33 no.1
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• pp.69-77
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• 2017

S The need for an automated geo-positioning approach for near real-time results and to boost cost-effectiveness has become increasingly urgent. Following this trend, a new approach to automatically compensate for the bias of the rational function model (RFM) was proposed. The core idea of this approach is to remove the bias of RFM only using tie points, which are corrected by matching with the digital elevation model (DEM) without any additional ground control points (GCPs). However, there has to be a additional evaluation according to the quality of DEM because DEM is used as a core element in this approach. To address this issue, this paper compared the quality effects of DEM in the conduct of the this approach using the Shuttle Radar Topographic Mission (SRTM) DEM with the spatial resolution of 90m. and the National Geographic Information Institute (NGII) DEM with the spatial resolution of 5m. One KOMPSAT-2 stereo-pair image acquired at Busan, Korea was used as experimental data. The accuracy was compared to 29 check points acquired by GPS surveying. After bias-compensation using the two DEMs, the Root Mean Square (RMS) errors were less than 6 m in all coordinate components. When SRTM DEM was used, the RMSE vector was about 11.2m. On the other hand, when NGII DEM was used, the RMSE vector was about 7.8 m. The experimental results showed that automated geo-positioning approach can be accomplished more effectively by using NGII DEM with higher resolution than SRTM DEM.

• Nuclear Engineering and Technology
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• v.46 no.3
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• pp.313-342
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• 2014

A Nuclear Energy Agency (NEA), Organization for Economic Co-operation and Development (OECD) benchmark for Uncertainty Analysis in Modeling (UAM) is defined in order to facilitate the development and validation of available uncertainty analysis and sensitivity analysis methods for best-estimate Light water Reactor (LWR) design and safety calculations. The benchmark has been named the OECD/NEA UAM-LWR benchmark, and has been divided into three phases each of which focuses on a different portion of the uncertainty propagation in LWR multi-physics and multi-scale analysis. Several different reactor cases are modeled at various phases of a reactor calculation. This paper discusses Phase I, known as the "Neutronics Phase", which is devoted mostly to the propagation of nuclear data (cross-section) uncertainty throughout steady-state stand-alone neutronics core calculations. Three reactor systems (for which design, operation and measured data are available) are rigorously studied in this benchmark: Peach Bottom Unit 2 BWR, Three Mile Island Unit 1 PWR, and VVER-1000 Kozloduy-6/Kalinin-3. Additional measured data is analyzed such as the KRITZ LEU criticality experiments and the SNEAK-7A and 7B experiments of the Karlsruhe Fast Critical Facility. Analyzed results include the top five neutron-nuclide reactions, which contribute the most to the prediction uncertainty in keff, as well as the uncertainty in key parameters of neutronics analysis such as microscopic and macroscopic cross-sections, six-group decay constants, assembly discontinuity factors, and axial and radial core power distributions. Conclusions are drawn regarding where further studies should be done to reduce uncertainties in key nuclide reaction uncertainties (i.e.: $^{238}U$ radiative capture and inelastic scattering (n, n') as well as the average number of neutrons released per fission event of $^{239}Pu$).

• Journal of Digital Convergence
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• v.16 no.3
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• pp.27-35
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• 2018

The purpose of this study is to design smart learning based extracurricular program of the university and to analyze the effect of core competencies. This program was formed by 10 teams with S and K University in Seoul, and run a daily camp format to use smart devices and apps. As a result, the participating students, communication skill, self-directed and creativity increased significantly. In addition, the educational effects of this program was positive changes in the areas of 'communication', 'self-directed', 'cooperative learning', 'problem solving' in the focus group interview. And the students responded that the use of smart devices and apps help to immerse in the program and increase their interest. The purpose of this study is to suggest new models and implications for the extracurricular program. In the future, we hope to develop the various smart learning based extracurricular programs for enhancing the competencies.

• Journal of Oriental Neuropsychiatry
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• v.31 no.2
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• pp.77-88
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• 2020

Objectives: The study evaluated middle-aged women using the Core Seven Emotions Inventory-short form (CSEI-s) followed by a correlation analysis with Menopause Rating Scale (MRS). Methods: In this study, the medical records of 47 women who visited W University Oriental Medicine Hospital and completed the CSEI-s and MRS were evaluated. A total of 47 women were analyzed using SPSS (Statistical Package for the Social Science, IBM, United States of America, Version 23.0). Frequency analysis, descriptive analysis, independent t-test, one-way ANOVA, Scheffe test, and correlation analysis were conducted. Results: 1. Approximately one-third of all subjects were more than cautious expressing joy and fright. 2. According to their educational status, high-school graduates thought they were superior to those with a bachelor's degree or above. 3. Anger was expressed with caution in the group with severe menopausal symptoms. 4. Anger, thought, depression, sorrow, fear, and fright showed a positive correlation with MRS scores. 5. Among premenopausal and postmenopausal women, fright was associated with menopausal symptoms and response by the autonomous nervous system. Conclusions: The results suggest that CSEI-s can be used to measure the psychological symptoms of middle-aged women.

• Nuclear Engineering and Technology
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• v.19 no.1
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• pp.34-41
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• 1987

This work concerns with a comparison of the 1-dimensional (or 1-D) load follow analysis method with reference to the detailed 3-dimensional (or 3-D) computations. For this purpose a 1-D two-group finite difference code, HLOFO, and a 3-D coarse-mesh code based on the modified Borresen's method, CMSNAC, are developed. The CMSNAC code is used to obtain the 3-D power peaks and reactivity parameters in response to power swing from 100 to 50 and back to 100% in the 12-3-6-3 load cycle for the BOL of the KORI Unit 1 PWR core. The 3-D result is then compared with the 1-D HLOFO computations, the cross section and buckling inputs of which are obtained by combining the flux-volume weighting scheme with the approximate flux from the auxiliary 3-D computations. It is shown that the 1-D computation has a limited accuracy, yet it is confirmed that it can describe the core axial average behavior which is fairly consistent with the detailed 3-D computation.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3533-3540
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• 2016

Background: Cigarette smoking is one of the leading global causes of premature and preventable death. In Brunei Darussalam, smoking-related diseases have been a primary cause of mortality for the past three decades. Despite the increasing efforts that have been made in recent years to reduce the consumption of tobacco products in Brunei, the prevalence of adolescent smoking cigarette, however has risen alarmingly, from 8.9% in 2013 to 11.4% in 2014, with a higher prevalence found in males (17.8%) than in females (4.8%). In response to the need for more effective smoking prevention programmes in Brunei, this study sought to explore factors that influence Bruneian male adolescents to start and continue smoking. Materials and Methods: A qualitative study using focus group discussions (FGDs) as the data collection method was conducted from October to November 2015. A total of 43 studentss, comprising 31 smokers and 12 non-smokers, aged 13-17 years, from two government secondary schools in Bandar Seri Begawan, participated in six FGDs. Discussions were recorded and translated. Transcripts were entered into NVivo10, before thematic analysis was conducted. Results: We identified three themes under the core construct of 'factors influencing smoking initiation' ('family as teachers', 'overt pressure from peers' and 'perceived smoking has many advantages') and three themes under the core construct of 'factors influencing smoking continuation' ('craving and addiction', 'smoking as a 'social activity' and 'easy accessibility of cigarettes'). Conclusions: Based on the findings, it is recommended that future prevention activities should be embedded in a comprehensive approach, involving all stakeholders within a community, and should be focused towards bringing a change in smoking and parenting behavior of parents, social norms within the culture towards all population levels, and at strengthening the existing non-smoking policies in schools and other public places where young people congregate.

• Polymer(Korea)
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• v.28 no.2
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• pp.154-161
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• 2004

Modified poly(4-vinylpyridine) was obtained by partial quarternization of nitrogen atoms in pyridine rings of poly(4-vinylpyridine) with methyl group. By means of laser light scattering and fluorescence, it was found that this modified polymer chains were aggregated in the aqueous solution and its structure was core-shell type. The hydrophobic parts of the chains were densely condensed in core part and the hydrophilic part of quarternized amino with positive charge formed the shell part. In the mixed system of modified poly(4-vinylpyridine) and anionic surfactant, sodium dodecyl sulfate, it was observed that a critical aggregation concentration existed and that this critical concentration was suddenly decreased above 0.1 M NaCl. The size change of aggregates was also investigated by dynamic light scattering while sodium dodecyl sulfate was added into polymer solution upto the critical aggregation concentration.

• Smart Media Journal
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• v.9 no.3
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• pp.130-141
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• 2020

The drone market in Korea is growing with a focus on the use of prevention, defense, exploration and surveying, search and rescue, video shooting, and facility management. However, the foreign dependence on drone's core technologies and components is high. Drone-powered countries such as the US and China are expanding the weaponization of drones, which can intensify trade wars between countries, such as strengthening import and export regulations and monopoly. Therefore, Korea should put R & D and localization of core technology, parts, and accessories of next generation drone first. For this, policy research and investment in infrastructure, equipment, and research personnel should be preceded. This study studied the evaluation of investment priorities by infrastructure sector (facility equipment, utilization field, and demand manpower) to foster small drone companies through literature studies. To this end, we expanded and reclassified e isting research, developed investment prioritization indicators through expert group interviews and reviews, derived future uncertainties, and selected investment priorities by infrastructure sector using AHP techniques. Finally, it proposed an infrastructure construction strategy to foster small drone companies in terms of drone development support, utilization support.