• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.4
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• pp.375-381
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• 2017

Recently, due to the increasing of interest about the eco-friendly concrete, it is being increased to use concretes containing by-products of industry such as fly ash, ground granulated blast furnace slag, silica fume, and etc. Especially, these are well known for improving the resistance to reinforcement corrosion in concrete and decreasing chloride ion penetration. The purpose of this experimental research is to evaluate the resistance to corrosion of reinforcement and critical chloride content of high volume fly ash concrete(HVFAC) which is replaced with fly ash for approximately 50% cement content. For this purpose, corrosion monitoring of reinforcement by half cell potential method was carried out for the cylindrical test specimens that the upper of reinforcement in concrete was exposed to detect the time of corrosion initiation for reinforcement. It was observed from the test result that the the time of corrosion initiation for reinforcement of HVFAC by the accelerated corrosion tests increased 1.2~1.3 times than plain concrete and the critical chloride contents of plain concrete and HVFAC were found to range $0.80{\sim}1.20kg/m^3$, $0.89{\sim}1.60kg/m^3$, respectively.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.743-748
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• 2002

Chloride ingress into concrete followed by reinforcement corrosion and deterioration of concrete structures is a major problem for many structures under chloride attacks. Large-scale concrete structures directly exposed to seawater such as SeoHae Grand Bridge are increasingly constructed along the coast in Korea. It is necessary to investigate the environmental conditions of concrete structures exposed to chloride attacks. In this study, the air-borne chloride contents of highway bridges exposed to marine environment in Korea were measured.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10b
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• pp.857-860
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• 2000

An experimental study on the behavior of Steel Fiber Reinforced Concrete Columns under eccentric compression are presented. Forth-one columns were tested; the variables were column type, eccentricity of load, fiber contents, and longitudinal reinforcement ratio. The column size was $250\times160$ mm in cross section with an effective length of 1150 mm. Eccentricity of load was varied in the range from 1/6 to 1/2 times the column depth. This paper is to provides a framework for basic understanding of the steel fiber concrete columns.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10b
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• pp.861-866
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• 2000

This experimental were investigated on the influence of steel fiber reinforcement on flexural behavior characteristics of slabs with various steel fiber contents $V_f$ and aspect ratio($\ell $/$\phi$). Deflection, crack widths, and strains of steel bar were measured with every load step. In the results of this experimental, the addition of steel fibers to conventionally reinforced concrete slab increased the ultimate load, reduced the creak width, the average crack spacing, and deflection.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.10a
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• pp.87-92
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• 1994

The main objective of this study is to determine the critical chloride ion concentrations in the pore solutions causing depassivation of steel reinforcement in concrete made with cements of different $C_3A$ contents. Cement pastes with water-ratio of 0.5 were prepared using four cements with $C_3A$ contents of 0.46, 5.97, 9.14, and 9.65 percent. The pastes were allowed to hydrate in sealed containers for 28days and then objected to pore solution expression. The expressed pore fluids were analyzed for chloride and hydroxyl ion concentrations. It was found that the free cholride concentration in the pore solution decreases significantly with an increase in the $C_3A$ content of the cement. With increasing level of chloride addition, although the alsolute amount of bound chloride increase, the ratio of bound to total chlorides decreases.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.537-542
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• 2009

The Question is to expend Non-Provide Taxes(so on Local Income Tax and Local Consumption Tax). Can we legislate Non-Provide Taxes and levy them to a taxpayer? This Paper is to study a Scheme of Solution for Expansion of Fiscal Decentralization and search Laws and Ordinance, Theories and Case Law of the Major states. Therefore This Study is to aim for expanding at Legislation Power of Local Tax.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.1210-1215
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• 2009

The domestic medical device industry compared by advanced nations continues a quick growth, also the level of technique is gradually improving. However, the high import percentage, low investment, shortage of professional manpower and etc. are remained as weaknesses in the competitive circumstance. In this paper I researched world medical device market and industry, and tried to find the development plan of the domestic medical device. The approach could be in mid-long term rather than short-term, The institutional improvement and support of the government, the production complex, the market segmentation and overseas marketing reinforcement and etc. are necessary for export expansion plan.

• Proceedings of the Korea Contents Association Conference
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• 2017.05a
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• pp.13-14
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• 2017

딥러닝을 비롯한 전반적인 인공지능에 대한 관심이 뜨겁다. 특정 영역에 영향력을 주었던 과거와 다르게 인공지능의 영향력은 인류문명 전체에 변화를 주고 있다. 예술 분야도 영향을 받고 있는데, 그 중 한 분야는 과학적 실험의 자료를 어떻게 시각화 하느냐의 문제를 풀다가 나오기도 한다. 자료를 시각화하는 것은 실험과정 및 결과를 과학자 및 독자들에게 쉽게 전달하기위한 것이다. 그런데, 그 시각화된 영상 중에는 미적인 아름다움이 있는 경우가 있다. 본 연구자는 강화학습의 정책이 어떻게 개선되고 있는지 보기위해 강화학습의 과정을 시각화 해서 검증하는 시도를 했다. 그 과정에서 만든 자료가 미술적인 관점에서도 아름다움이 있는 작품을 만들 수 있다는 확신이 들어서 강화학습용 디지탈예술 도구를 만들어 작품을 생성해 보았다.

• Journal of the Korean Wood Science and Technology
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• v.12 no.1
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• pp.38-43
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• 1984

Water soluble urea-melamine-phenol copolymer adhesive manufactured with 80 percent of urea resin contents was manufactured by different molar ratio for a high temperature curing type, and their properties and strengthes were examined through manufactures of plywood with Kapur (Dryobalanops spp.) veneers. The results are summarized as follows: 1. Specific gravities of air dried plywood manufactured from each adhesive ranged from 0.78 to 0.84 and their moisture contents met the KS requirement. 2. In dry and wet shear strength, $U_{80}M_{10}P_{10}$ copolymer resin showed the highest value and urea resin was the lowest, indicating that melamine and phenol were effective for increasing glue shear strength of urea resin. 3. In case of glue shear strength after boiling test, phenolic resin was the nest and melamine was not so effective as phenol on reinforcement of boiling water resistance of urea resin.

• International Journal of Contents
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• v.17 no.4
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• pp.16-34
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• 2021

The purpose of this study was to explore how designers use software-based design tools for ideation and collaboration (for two cases: with designers and with developers). We conducted logistic regression analysis and random forest analysis. Software-based design tools are more popular among product designers and affiliated with design organizations with 51 to 100 members. We identify the features that influence designers to use design tools for the ideation and collaboration, and how these usage patterns are interrelated. Interrelated usage pattern is a key consideration for location of the menu and convenience of use. The results imply that reinforcement of the design tool features per designer profile is required and that design management should be consistent with the field of design and the nature of the organization.