• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.05a
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• pp.181-183
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• 2002

A new deformation process termed "continuouis confined sup shearing" (CCSS) has been developed for shear deformation of metallic sheets. The tools of CCSS were designed to provide a constant shear deformation of the order of 0.5 per pass while preserving the original sheet shape. In order to clarify the evolution of texture and microstructure during CCSS, strips of the aluminum alloy AA3004 were deformed by CCSS in up to three passes. FEM results indicated that CCSS provides a quite uniform shear deformation at thickness layers close to the strip center, although the deformation is not homogeneous in the die channel, in particular at the surface layers. The rolling texture of the initial sheet decreased during CCSS, and preferred orientations along two fibers developed. However, with an increasing number of CCSS passes the deformation texture did not develop futher. The evolution of annealing textures depended on the number of CCSS passes. A strong {112}<110> component in the deformation texture led to the formation of a strong {111}<112) orientation in the annealing texture. Observations by TEM and EBSD revealed the formation of very fine grains of ∼1.0$\mu\textrm{m}$ after CCSS.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.96-98
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• 2003

The evolution of texture and microstructure during continuous confined strip shearing (CCSS) in aluminum 3003 alloy sheets was investigated. The tools of CCSS based on the equal channel angular pressing (ECAP) were designed to provide a constant shear deformation of the order of 0.5 per pass while preserving the original sheet shape. FEM results indicated that the shear formation is not homogeneous throughout the sample thickness, in particular at the surface layers. A randomization of textures took place during the CCSS deformation. Observations by TEM and EBSD revealed the formation of sub-micrometer sized grains after CCSS.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.176-178
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• 2003

Strip samples of AA 3103 were deformed by Continuous confined strip shearing (CCSS). The CCSS process was designed to provide a repeated shear deformation in metallic sheet materials. CCSS led to the formation of characteristic shear textures comprising a pronounced｛111｝＜uvw＞ orientations. The intensity of the deformation texture hardly increased with increasing number of CCSS passes. EBSD equipped in a FESEM with a high beam current revealed the formation of fine grains even after annealing for the recrystallization.

• East Asian mathematical journal
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• v.27 no.4
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• pp.471-483
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• 2011

The purpose of this study is to introduce the Common Core State Standards (CCSS) for mathematics which is released on June 2, 2010 in the U.S.A. The common core state standards are aligned with college and work expectations, and include rigorous content and application of knowledge through high-order skills. The most distinguishable differences between the CCSS standards and the NCTM standards are that the CCSS standards considers the mathematical modeling as one of the mathematical content domains such as algebra, geometry, ets, and the standards are designed by working together with school leaders of all states.

• Transactions of Materials Processing
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• v.12 no.1
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• pp.43-48
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• 2003

The strain state during the continuous confined strip shearing (CCSS) based on ECAP was tackled by means of a two-dimensional FEM analysis. The deformation of AA 1100 sheet in the CCSS apparatus was composed of three distinct processes of rolling, bending and shearing. The pronounced difference in the friction conditions on the upper and lower roll surfaces led to the different variation of the strain component ${epsilon}_13$ throughout the thickness of the aluminum sheet. Strain accompanying bending was negligible because of a large radius of curvature. The shear deformation was concentrated at the corner of the CCSSchannel where the abrupt change in the direction of material flow occurred. The process variables involving the CCSS-die design and frictions between tools and strip influenced the evolution of shear strains during CCSS.

• Transactions of Materials Processing
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• v.13 no.4
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• pp.382-387
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• 2004

The continuous confined strip shearing (CCSS) based on the equal channel angular pressing (ECAP) was modeled by means of a rigid-plastic two-dimensional finite element method (FEM). Parallel to the simulations, samples of AA 1050 sheets were experimentally deformed by CCSS. The CCSS deformation led to the formation of through thickness texture gradients comprising a strong shear texture in the sheet center and weak shear textures in the sheet surfaces. FEM analysis revealed variations in the strain component $\varepsilon_13$ along the sample thickness direction, which gave rise to the evolution of different textures. A high friction between the sample and die surface was responsible for lowering intensities of the shear texture components in thickness layers close to the surfaces.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.215-217
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• 2004

In order to obtain the initial starting sample having a random texture and fine grains, aluminum alloy 3103 sheets were repeatedly deformed by CCSS up to six passages and subsequently annealed at $300^{\circ}C$ for 1h. These samples were cold rolled at room temperature and also warm rolled at $250^{\circ}C$. Changes in rolling temperature gave rise to the different texture evolution. Warm rolling led to the pronounced texture gradients comprising the shear texture at the surface and the rolling texture at the sheet center. The formation of the rolling texture components, i.e., the ${\beta}$-fiber, was promoted by cold rolling than warm rolling.

• Korean Journal of Comparative Education
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• v.28 no.3
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• pp.333-354
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• 2018

The study aimed to compare and analyze Nuri curriculum and contents for mathematics in Korea and the Common Core State Standards(CCSS) and New Jersey Preschool Standards for mathematics in the United States. With the results as basis, this study intended to provide suggestions and directions for improving Nuri curriculum of mathematics for young children. For the goal of this study, educational goals, categories of contents, and specific contents were reviewed. First, results of this study indicated that Nuri curriculum for mathematics provides comprehensive educational goals that promote problem-solving ability in everyday contexts with composing mathematical knowledge. On the contrary, CCSS and Preschool Standards provide specific educational goals that focus on children's mathematical skills and concepts. Second, the contents of both countries' curriculum concentrate on 'counting and cardinality', 'measurement', and 'spatial and geometric sense.' There are 5 categories of CCSS, 4 categories of Preschool Standards based on CCSS and one category of Nuri curriculum for mathematics. Third, there are the differences between the two countries' curriculum in continuity from kindergarten to first grade and description method for curriculum.

• KIPS Transactions on Computer and Communication Systems
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• v.11 no.8
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• pp.249-258
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• 2022

Since the advent of Bitcoin, various virtual assets have been actively traded through virtual asset services of virtual asset exchanges. Recently, security accidents have frequently occurred in virtual asset exchanges, so the government is obligated to obtain information security management system (ISMS) certification to strengthen information protection of virtual asset exchanges, and 56 additional specialized items have been established. In this paper, we compared the domain importance of ISMS and CryptoCurrency Security Standard (CCSS) which is a set of requirements for all information systems that make use of cryptocurrencies, and analyzed the results after mapping them to gain insight into the characteristics of each certification system. Improvements for 4 items of High Level were derived by classifying the priorities for improvement items into 3 stages: High, Medium, and Low. These results can provide priority for virtual asset and information system security, support method and systematic decision-making on improvement of certified items, and contribute to vitalization of virtual asset transactions by enhancing the reliability and safety of virtual asset services.

• Journal of the Korean Institute of Telematics and Electronics
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• v.10 no.4
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• pp.44-59
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• 1973