http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Density Functional Theory를 이용한 CaO 안정화 Cubic-HfO<sub>2</sub>의 산소 공공 구조 연구
김종훈,김대희,이병언,황진하,김영철,Kim, Jong-Hoon,Kim, Dae-Hee,Lee, Byeong-Eon,Hwang, Jin-Ha,Kim, Yeong-Cheol 한국재료학회 2008 한국재료학회지 Vol.18 No.12
Calcia (CaO) stabilized cubic-$HfO_2$ is studied by density functional theory (DFT) with generalized gradient approximation (GGA). When a Ca atom is substituted for a Hf atom, an oxygen vacancy is produced to satisfy the charge neutrality. The lattice parameter of a $2{\times}2{\times}2$ cubic $HfO_2$ supercell then increases by $0.02\;{\AA}$. The oxygen atoms closest to the oxygen vacancy are attracted to the vacancy as the vacancy is positive compared to the oxygen ion. When the oxygen vacancy is located at the site closest to the Ca atom, the total energy of $HfO_2$ reaches its minimum. The energy barriers for the migration of the oxygen vacancy were calculated. The energy barriers between the first and the second nearest sites, the second and the third nearest sites, and the third and fourth nearest sites are 0.2, 0.5, and 0.24 eV, respectively. The oxygen vacancies at the third and fourth nearest sites relative to the Ca atom represent the oxygen vacancies in undoped $HfO_2$. Therefore, the energy barrier for oxygen migration in the $HfO_2$ gate dielectric is 0.24 eV, which can explain the origin of gate dielectric leakage.
Ubiquitous Product Life cycle Support System: 아키텍처 및 공작기계로의 적용
윤수철(SooCheol Yoon),서석환(Suk-Hwan Suh),이병언(Byeong-Eon Lee) (사)한국CDE학회 2011 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2011 No.1
Product life cycle information encompasses entire life cycle information of product including design, manufacturing, distribution, usage and disposal phase. That information is useful to support system for efficient manufacturing, maintenance and providing service. However it is hard to collect information after distribution phases, and information is not gathered in real time although it is possible to collect life cycle information at design and manufacturing phase. In this research we propose UPLS system based on UbiDMR paradigm, and propose generic architecture by analyzing functional and data requirement of the system. Works done in this paper is validated by applying to machine tool lifecycle and develop machine tool life cycle data model.