• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2002년도 춘계학술대회 논문집
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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.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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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.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 추계학술대회논문집
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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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• 제27권4호
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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.

• 소성∙가공
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• 제12권1호
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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.

• 소성∙가공
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• 제13권4호
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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.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 추계학술대회논문집
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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.

• 비교교육연구
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• 제28권3호
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• pp.333-354
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• 2018

본 연구는 우리나라 누리과정의 수학교육과 미국의 CCSS 및 뉴저지 주 Preschool Standards 수학교육과정을 비교 분석함으로써 누리과정 수학교육내용에 필요한 것이 무엇인지 시사점을 도출하여 향후 누리과정 수학교육의 개정 및 발전을 위한 기초자료를 제공하고자 하였다. 분석준거는 선행연구를 참고하여 목표, 내용범주 및 내용, 세부 내용 및 특징으로 정하였다. 그 결과 첫째, 우리나라 누리과정은 수학적 지식을 구성하고 이를 바탕으로 일상의 문제를 해결하는 능력을 강조한 포괄적 목표를 제시한 반면 미국의 수학교육 목표는 유아들이 습득해야 할 수학적 내용 및 개념을 중심으로 구체적으로 제시하고 있다. 둘째, 한국과 미국의 내용범주 및 내용은 두 나라 모두 수와연산의 기초, 측정, 공간 및 도형 등에 대한 것을 다루고 있다. 우리나라 누리과정 수학교육은 자연탐구영역에서 1개의 내용범주를 제시하고 있고, 미국 CCSS의 내용범주는 주요 수학적 개념 5개이며 Preschool Standards 내용범주는 4개로 제시 되어있다. 셋째, 두 나라 유아수학교육은 유 초 연계를 포함한 연령 및 학년별 연계성과 기술방법에 차이점이 있다. 이를 통해 누리과정 유아수학교육 내용 개선 시 고려해야 할 점을 살펴보았다.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제11권8호
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• pp.249-258
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• 2022

비트코인이 등장한 이후, 다양한 가상자산이 가상자산 거래소의 가상자산 서비스를 통해 활발하게 거래되고 있다. 최근 가상자산거래소에 대한 보안사고가 자주 발생하고 있어 정부는 가상자산 거래소의 정보보호 강화를 위해 Information Security Management System (ISMS) 인증획득을 의무화하고 있으며, 이를 위한 56개 특화항목을 추가로 제정하였다. 본 논문에서는 ISMS와 암호화폐를 이용하는 모든 정보시스템에 대한 요구사항을 담고있는 CryptoCurrency Security Standard (CCSS)의 도메인 중요도를 비교하고 상호매핑을 한 후 그 결과를 분석하여 각 인증제도의 특성을 통찰하였으며, 도출된 개선항목의 중요도 평가를 통해 개선항목에 대한 우선순위를 High, Medium, Low 등 3단계로 분류하여 High Level 4가지 항목에 대한 개선사항들을 도출하였다. 이러한 결과는 가상자산 및 정보시스템 보안에 대한 우선순위를 제공하고 인증항목 개선에 대한 방법 및 체계적인 의사결정을 지원할 수 있을 뿐만 아니라 가상자산서비스에 대한 신뢰성 및 안전성을 제고하여 가상자산 거래 활성화에 기여할 수 있을 것으로 보인다.

• 대한전자공학회논문지
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• 제10권4호
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• pp.44-59
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• 1973