• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.481-484
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• 2004

This study was performed to analyze effect of cyclic load during CFS curing on the behavior of RC beam strengthened with CFS. In the experiment, five different beginning times of cyclic load and two different strengthening amounts of CFS were chosen for experiment parameters. From the experimental results, it could be known that the cyclic load during CFS curing might give detrimental effects to the CFS strengthening effects compared to without cyclic load cases.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.835-840
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• 2002

The purpose of this study is to analyze the reinforcement effect of the RC compressive member confined with carbon fiber sheets and to suggest better transverse confinement coefficient(k$_1$) than one's in the existing analysis equations. Showing amounts of CPS in terms of ratio of transverse reinforcement to cross-section, it comes to be possible to calculate the objective and quantitative reinforcement amounts and to estimate the overlapping length of CFS that can influence on all its confinement effect. The previous parameters were compared using the existing experimental test data, then analyzed for the merits and demerits of existing parameters through the coefficient of correlation(R). The proposed parameters were derived in such a way that established parameters and their combination were obtained from the analytical study and then determined by regression analysis using the previous test data.

• Journal of the Korea institute for structural maintenance and inspection
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• v.3 no.3
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• pp.203-211
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• 1999

This study is to examine the feasibility of carbon fiber sheet(CFS), a kind of fiber reinforced plastic(FRP), for a repair and reinforcement of R/C beams. The flexural strength of R/C beams, that were preloaded and then the cracks were repaired, maintains that of the uncracked R/C beams. The flexural strength of R/C beams increases with the reinforcement of CFS. In order to practically apply the repair and reinforcement method, further research is needed for the distribution, amount, and bond of CFS. In this study, an experiment was conducted for R/C beams reinforced with CFS, for various wrapping method and amounts of CFS. Experimental results showed the wrapping method increasing the bond area and amount of CFS layer caused the increase in the strength of the beams. It is found that the strength of CFS should be used as 70% of the maximum strength in retrofitting reinforced concrete beams in evaluating flexural capacity on the basis of ultimate strength design method.

• Journal of the Korea institute for structural maintenance and inspection
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• v.4 no.3
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• pp.169-176
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• 2000

In the strengthening of the existed reinforced concrete(RC) structures, it is required that the more rational strengthening method and the amounts of strengthening materials would be decided under the consideration of the present state of RC structures. Therefore, this study examined the strengthening effects of concrete cylinders strengthened with carbon fiber sheet(CFS). In this studying we modeled the reduction of internal forces and the initial strains of concrete cylinders as the load history over the elastic limit. From the results, it revealed that the strengthening of two layer CFS was more effective on the concrete cylinders under the action of load history such as cyclic and cracking load.

• Microbiology and Biotechnology Letters
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• v.45 no.4
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• pp.299-304
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• 2017

Biogenic amines such as histamine, tyramine, cadaverine, and putrescine may have detrimental effects on consumers' health; therefore, they must be considered hazardous substances in foods. In recent years, the application of microorganisms that can degrade biogenic amines has become an emerging method for reducing the amount of these amines in foods. Primarily, Bacillus sp. BCNU 9171 was isolated from Doenjang, a Korean traditional fermented soybean paste. The inhibitory effects of the cell-free supernatant (CFS) of Bacillus sp. BCNU 9171 on biogenic amine production by 4 amine-positive food pathogenic bacteria were investigated using high performance liquid chromatography (HPLC). Our results showed that 4 different CFS concentrations-10% [1 ml CFS + 9 ml histidine decarboxylase broth (HDB)], 25% (2.5 ml CFS + 7.5 ml HDB), 50% (5 ml CFS + 5 ml HDB), and 75% (7.5 ml CFS + 2.5 ml HDB)-reduced the biogenic amine production up to 87% compared with that of the control without CFS. These results suggested that it is advisable to use Bacillus sp. strain BCNU 9171 as a starter organism for the manufacture of fermented foods and to ensure food safety since it prevents the accumulation of high amounts of biogenic amines in fermented foods by amine-positive bacteria.

• The Journal of Engineering Geology
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• v.32 no.4
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• pp.643-659
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• 2022

Geologic sequestration technologies such as CCS (carbon capture and storage), EGS (enhanced geothermal systems), and EOR (enhanced oil recovery) have been widely implemented in recent years, prompting evaluation of the mechanical stability of storage sites. As fluid injection can stimulate mechanical instability in storage layers by perturbing the stress state and pore pressure, poroelastic models considering various injection scenarios are required. In this study, we calculate the pore pressure, stress distribution, and vertical displacement along a surface using commercial finite element software (COMSOL); fault slips are subsequently simulated using PyLith, an open-source finite element software. The displacement fields, are obtained from PyLith is transferred back to COMSOL to determine changes in coseismic stresses and surface displacements. Our sequential use of COMSOL-PyLith-COMSOL for poroelastic modeling of fluid-injection and induced-earthquakes reveals large variations of pore pressure, vertical displacement, and Coulomb failure stress change during injection periods. On the other hand, the residual stress diffuses into the remote field after injection stops. This flow pattern suggests the necessity of numerical modeling and long-term monitoring, even after injection has stopped. We found that the time at which the Coulomb failure stress reaches the critical point greatly varies with the hydraulic and poroelastic properties (e.g., permeability and Biot-Willis coefficient) of the fault and injection layer. We suggest that an understanding of the detailed physical properties of the surrounding layer is important in selecting the injection site. Our numerical results showing the surface displacement and deviatoric stress distribution with different amounts of fault slip highlight the need to test more variable fault slip scenarios.

• International journal of advanced smart convergence
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• v.10 no.3
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• pp.149-156
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• 2021

Today, 3D softwares have become an essential tool in all areas of Video, including Movies, Animations, CFs, Motion Graphics and Games. One of the most commonly used fields is the 3D character video part. However, these 3D character animations and motion graphics softwares are difficult to learn and too much to learn, making it difficult to learn them all in a university education with a limited time of four years. In this paper, many Inverse kinematics tools, which are essential in the 3D character animations and motion graphics field, compare and analyze the strengths and weaknesses of each tool, focusing on Bone, Character Studio, and Character Animation Toolkit, which are most commonly used in work fields. And use Delphi techniques for 3D experts to secure objectivity. Therefore, for universities that require large amounts of teaching in a limited time, I propose an analysis of which of the above three Inverse Kinetics tools is advantageous for students to select and focus on for efficient education.