• Microbiology and Biotechnology Letters
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• v.16 no.4
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• pp.297-302
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• 1988

The protoplasts of Saccharomyces cerevisiae D-71, a thermophilic strain and Zygosaccharomyces rouxii SR-S, an osmotolerant strain were fused, and a fusant (FS-RN 1) was selected, then was characterized for its genetic stability, DNA content, cell capacity, growth rate, tolerance to salts and chemicals, $\beta$-fructofuranosidase level and ethanol fermenting activity. After 6 months of preservation, 5.8% of the fusant clones were segregated to parental types. The DNA content and cell capacity of the fusant were greater than those of the parental strains. Lag period of growth for the fusant was longer than those for the parents. The fusant colonies showed pink-color reaction to triphenyltetrazolium chloride(TTC) test. The fusant appeared to have resistances to NaCl at moderate levels between both parental strains, and resistances to KCI, sodium propionate and cycloheximide similar to either one of the parents. $\beta$-Fructofuranosidase activity of the fusant was 24.2$\times$10$^{-3}$/IU/g(dry wt) for 3 days culture. Ethanol yields ofter 4 days of fermentation by the fusant at 3$0^{\circ}C$ were : 6.0%(v/v) from 40% of glucose and 8.8%(v/v) from 20% of sucrose.

• Journal of the Society of Disaster Information
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• v.11 no.3
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• pp.318-328
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• 2015

Effective urban flood reduction and restoration of natural water cycle at present include the application of permeable pavements. The application of permeable pavement addresses urban water cycle and disaster related events which gained attention internationally. However, few researches have been conducted to investigate unsaturated behavior and evaluate the water characteristics curves of these type of pavement materials most especially in the unsaturated state. In this study, first the saturated permeability and the soil-water characteristics curve of a pervious concrete are evaluated based on laboratory tests, and, based on experimental results, the infiltration of permeable pavement system is numerically modelled. In the soil-water characteristics curve of a pervious concrete, the volumetric water content drops very steeply after the air entry value with increasing matric suction. From the finite element analyses, the performance of the permeable pavement when compared to impermeable pavement, confirmed that the whole system effectively delayed and reduced runoff.

• Journal of Digital Convergence
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• v.17 no.10
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• pp.373-379
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• 2019

Polymethyl methacrylate (PMMA), a self-polymerizing resin for removable orthodontic devices, has been used as a dental orthodontic device for many years because of its advantages such as color stability, volume stability, and tissue compatibility. However, such a removable orthodontic device has a disadvantage that the longer the use in the oral cavity due to the low strength of the PMMA fracture of the orthodontic device resin in use. In this study, zinc nanoparticles (ZNP) were mixed with orthodontic PMMA to introduce strength effect. Rectangular samples ($1.4{\times}3.0{\times}19.0mm$) of orthodontic PMMA (0, 0.5, 1.0, 2.0 and 4.0%) containing ZNP were prepared. The finished specimen was tested for three-point bending strength at a speed of 1 mm / min, and the Vickers hardness was measured three times using a hardness tester. The surface roughness was measured with a surface roughness. As a result, the 3-point bending strength did not change significantly (p>0.05). Surface energy increased significantly. As a result, we successfully synthesized ZNP in this study and prepared the dispersed resin specimen for calibration. It will be possible to develop high-density dental orthodontic resins.

• Journal of the Korean GEO-environmental Society
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• v.12 no.7
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• pp.57-65
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• 2011

Numerical simulations by three-dimensional Particle Flow Code($PFC^{3D}$, Itasca) considering distinct element method (DEM) were carried out for prediction of triaxial compression test with sand material. The effect of scale conditions for numerical model and distinct material on final prediction results was analyzed by numerical models under various scale conditions, and following observations were made from the numerical experiments. It is very useful to model the initial material condition without any porosity conversion from 2-D to 3-D DEM. Numerical experiments have shown that in all cases considered, 3D distinct element modeling could provide good agreement on stress-strain behavior, volume change and strength properties with laboratory testing results. It was important thing to assess reasonable scale ratio of numerical model and distinct elements for saving calculation time and securing calculation efficiency under condition with accuracy and appropriateness as numerical laboratory. As results of DEM simulations under various scale conditions, most of results show that shear strength properties as cohesion and internal friction angle are similar in condition of $D_{mod}/D_{gmax}$ < 10. It shows that 3-D distinct element method could be used as efficient tool to assess strength properties by numerical laboratory technique.

• The Journal of Korean Philosophical History
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• no.30
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• pp.59-86
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• 2010

This paper tries to study theoretical transformation about modernity by analyzing changes of the concepts of Gaining Knowledge of the Study of Things(格物致知). Gaining Knowledge of the Study of Things(格物致知) was the main concept to explain the thought of Neo-Confucianism(性理學). But in the Modern era Gaining Knowledge of the Study of Things(格物致知) was understood as the meaning of Science. In Neo-Confucianism(性理學) Gaining Knowledge of the Study of Things(格物致知) was closely related to the side of human duty and the moral value judgement. But in the modern meaning Gaining Knowledge of the Study of Things(格物致知: Science) was focused to scientific study of the objective matter. So the Science on Gaining Knowledge of the Study of Things(格物致知學) effect to breakup the thinking of Neo-Confucianism(性理學).

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.7
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• pp.922-930
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• 2020

Marine accidents involving fishing boats, caused by a loss of stability, have been increasing over the last decade. One of the main reasons for these accidents is a sudden wind attacks. In this regard, the wind loads acting on the ship hull need to be estimated accurately for safety assessments of the motion and maneuverability of the ship. Therefore, this study aims to develop a computational model for the inlet boundary condition and to numerically estimate the wind load acting on a fishing boat. In particular, wind loads acting on a fishing boat at the wind speed profile boundary condition were compared with the numerical results obtained under uniform wind speed. The wind loads were estimated at intervals of 15° over the range of 0° to 180°, and i.e., a total of 13 cases. Furthermore, a numerical mesh model was developed based on the results of the mesh dependency test. The numerical analysis was performed using the RANS-based commercial solver STAR-CCM+ (ver. 13.06) with the k-ω turbulent model in the steady state. The wind loads for surge, sway, and heave motions were reduced by 39.5 %, 41.6 %, and 46.1 % and roll, pitch, and yaw motions were 48.2 %, 50.6 %, and 36.5 %, respectively, as compared with the values under uniform wind speed. It was confirmed that the developed inlet boundary condition describing the wind speed gradient with respect to height features higher accuracy than the boundary condition of uniform wind speed. The insights obtained in this study can be useful for the development of a numerical computation method for ships.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.7
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• pp.1244-1251
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• 2022

Marine accidents due to a loss of stability, have been gradually increasing over the last decade. Measures must be taken on the roll reduction of a ship. Amongst the measures, building an anti-roll tank in a ship is recognized as the most simple and effective way to reduce the roll motion. Therefore, this study aims to develop a computational model for a U-tube type anti-roll tank and to validate it by experiment. In particular, to validate the developed computational model, the height of the free surface in the tank was measured in the experiment. To develop a computational model, the mesh dependency test was carried out. Further, the effects of a turbulence model, time step size, and the number of iterations on the numerical solution were analyzed. In summary, a U-tube type anti-roll tank simulation had to be performed accurately with conditions of a realizable k-𝜖 turbulence model, 10^-2s time step size, and 15 iterations. In validation, the two cases of measured data from the experiment were compared with the numerical results. In the present study, STAR-CCM+ (ver. 17.02), a RANS-based commercial solver was used.

• Korean Journal of Social Welfare Studies
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• v.41 no.1
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• pp.5-37
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• 2010

The purpose of this study is to see the motive, processes and strategies of change in poor single mother self-help group and analyze meaning in the self help group, agencies and themselves by change. As to this discussion, We seek to grope practical ways for self-help group. By using Participatory Action Research, We intended to an alternative plan in collaborating between practitioners and all concerned. Following four-step-process in this methodology, we explored processes of changing and considered social work practical meaning. On results, first, The motive have come from critical minds that motivate them to choose their way subjectively. We concluded that they have a necessity of change as a groping activity within their capability. Second, On process trying to be changed, They have made initiative decisions about how extensive and deep their changes should be, by discussion being themselves. So they have agreed to aim at purposeful activities beyond just emotional support. Third, they suggested and planned meaningful action as a specific strategy for changing and all these were done by local community volunteering and lecturing for supporting single mother. In conclusion, The 'Change' single mother group activity aim at is, based on subjective decision, to change a practice of a social worker into a practice of participant, and to develop social empowerment more improved to control social condition, which is forming their life, by their own choice. Furthermore, It needs to be considered approach to Community for overcome limits of self help group activities. Based on these consequences, We presented social work practical meaning.

• Journal of the Korean Society of Radiology
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• v.17 no.7
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• pp.1157-1164
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• 2023

This study measures the additional dose for each treatment area using kV X-ray based OBI (On-Board Imager) and CBCT (Cone-Beam CT), which have excellent spatial resolution and contrast, and evaluates the adequacy and stability of radiation management aspects of IGRT. The subjects of the experiment were examined with OBI and CBCT attached to a linear accelerator (Clinac IX), and ring-shaped Halcyon CBCT under imaging conditions for each treatment area, and the dose at the center was measured using an ion chamber. OBI single fraction dose was measured as 0.77 mGy in the head area, 3.04 mGy in the chest area, and 7.19 mGy in the pelvic area. The absorbed doses from the two devices, Clinac IX CBCT and Halcyon CBCT, were measured to be similar in the pelvic area, at 70.04 mGy and 70.45 mGy. and in chest CBCT, the Clinac IX absorbed dose (70.05 mGy) was higher than the Halcyon absorbed dose (21.01 mGy). The absorbed dose to the head area was also higher than that of Clinac IX (9.08 mGy) and Halcyon (5.44 mGy). In kV X-ray-based IGRT, additional radiation exposure due to photoelectric absorption may affect the overall volume of the treatment area, and caution is required.

• Journal of the Korean Geographical Society
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• v.30 no.4
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• pp.364-388
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• 1995

Even though rarely recognized as a separate approach, the institutional approach in geography is defined as an attempt to seek an explanation of the phenomena of geographical interest through focusing on the effects of institutional structure and actions. It can provide interdisciplinary links with other works and can offer complementary explanations for geographical interests. The concerns for institutions in geography can be found in early studies, the study of the state, the managerial approach, and the regulation approach. The Korean financial systems can provide good examples to apply institutional concepts into creating spatial outcomes, as it has been regarded as a useful tool to promote Korean economic development. Behind the current spatial pattern of financial systems, four different stages of institutional changes are identified in Korea. Each stage has different institutional features reflecting unique spatial implication.