• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1999년도 PROCEEDINGS OF 99 INTERNATIONAL CONFERENCE OF THE KACG AND 6TH KOREA·JAPAN EMG SYMPOSIUM (ELECTRONIC MATERIALS GROWTH SYMPOSIUM), HANYANG UNIVERSITY, SEOUL, 06월 09일 JUNE 1999
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• pp.51-67
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• 1999

The growth of crystals with high melting points tfus$\geq$1$600^{\circ}C$ faces the researcher with experimental problems, as the choice of materials that withstand such high t is rather limited. Many metallic construction materials are in this high t range already molten or exhibit at least a drastically reduced mechanical strength. The very few materials with tfus》1$600^{\circ}C$ as e.g. W, Mo, and partially even Ir are more or less sensitive against oxygen upon heating. Whenever possible, high t crystal growth is performed under inert atmosphere (noble gases). Unfortunately, any oxides are not thermodynamically stable under such conditions, as reduction takes place within such atmosphere. A thoroughly search for suitable growth conditions has to be performed, that are on the one side "oxidative enough" to keep the oxides stable and on the other side "reductive enough" to avoid destruction of constructive parts of the crystal growth assembly. The relevant parameters are t and the oxygen partial pressure pO2. The paper discusses quantitatively relevant properties of interesting oxides and construction materials and ways to forecast their behavior under growth conditions.r growth conditions.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2004년도 춘계공동학술대회 논문집
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• pp.143-146
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• 2004

With the rapid growth of e-commerce, marketers are able to observe not only purchasing behavior on what and when customers purchased, but also the individual Web usage behavior that affect purchasing. The richness of this information has the potential to provide marketers with an in-depth understanding of customer. Using commonly available Web log data, this paper examines Web usage behaviors at the individual level. By decomposing the buying process into a pattern of visits and purchase conversion at each visit, we can better understand the relationship between Web usage behavior and purchase decision. This allows us to more accurately forecast a shopper's future purchase decision at the site and hence determine the value of individual customers to the siteAccording to our research, not only information seeking behavior but also visiting duration of a customer and participative behavior such as participation in event should be considered as important predicators of purchase decision of customer in a cosmetic internet shopping mall.

• 대한수학회지
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• 제33권2호
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• pp.455-468
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• 1996

Certain analytic behavior of geometric objects defined on a Riemannian manifold depends on some very crude properties of the manifold. Some of those crude invariants are the volume growth rate, isoperimetric constants, and the likes. However, these crude invariants sometimes exercise surprising control over the analytic behavior.

• 한국콘텐츠학회논문지
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• 제11권9호
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• pp.302-314
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• 2011

오늘날 급변하는 경영환경에서 기업이 생존 유지를 위해서 리더의 새로운 역할이 강조되는 가운데, 최근에 주목 받는 리더십인 서번트 리더십을 전략적으로 잘 활용함으로써 조직성과를 극대화 하도록 하여야 한다. 본 연구는 은행, 보험업, 증권, 컨설팅 등 서비스업종의 종업원들을 대상으로 유효설문지 435부의 자료를 수집하여 LISREL 8.30을 이용하여 분석하였다. 서번트 리더십이 심리적 임파워먼트를 통해서 조직시민행동에 미치는 영향을 살펴보았다. 그 결과는 다음과 같다. 첫째, 서번트 리더십의 행동특성 중 공감과 도덕성을 제외한 성장, 비젼, 공동체형성이 심리적 임파워먼트를 높아지게 하는 변인으로 나타났다. 둘째, 조직구성원들의 심리적 임파워먼트가 조직시민행동에 정(+)의 영향을 미치는 것으로 나타났는데, 이러한 결과는 종업원들에게 심리적 임파워먼트를 강화시켜 줄수록 조직 시민행동이 높아짐을 의미한다. 셋째, 서번트 리더십의 행동특성 중 공감과 도덕성을 제외한 성장, 비젼, 공동체형성이 조직구성원의 심리적 임파워먼트를 통하여 조직시민행동에 유의한 정(+)의 영향을 미치는 것으로 나타났다. 이와 같은 결과는 리더의 서번트 리더십이 임파워먼트를 통해 구성원의 조직시민행동을 높이고 있음을 의미한다. 이는 부하들을 임파워시키고 이것이 자발적인 행동으로 이어질 수 있도록 하기 위해서는 리더의 서번트 리더십이 중요함을 의미한다.

• 한국분말재료학회지
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• 제25권2호
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• pp.104-108
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• 2018

Grain-growth behavior in the $95Na_{1/2}Bi_{1/2}TiO_3-5BaTiO_3$ (mole fraction, NBT-5BT) system has been investigated with the addition of $Na_2CO_3$. When $Na_2CO_3$ is added to NBT-5BT, the growth rate is higher than desired and grains are already impinging each other during the initial stage of sintering. The grain size decreases as the sintering temperature increases. With the addition of $Na_2CO_3$, a liquid phase infiltrates the interfaces between grains during sintering. The interface structure can be changed to be more faceted and the interface migration rate can increase due to fast material transport through the liquid phase. As the sintering temperature increases, the impingement of abnormal grains increases because the number of abnormal grains increases. Therefore, the average grain size of abnormal grains can be decreased as the temperature increases. The phenomenon can provide evidence that grain coarsening in NBT-5BT with addition of $Na_2CO_3$ is governed by the growth of facet planes, which would occur via mixed control.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.885-886
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• 2012

• 한국결정성장학회지
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• 제8권1호
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• pp.106-110
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• 1998

본 논문에서는 먼저 다층흡착에서 각 흡착층의 결합에너지가 서로 다른 경우의 흡착 등온선을 유도한다. 그리고 유도된 흡착등온식이 저압영역에서 헨리의 실험법칙을 잘 만족시킴을 보인다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2002년도 제22회 학술발표회 초록집
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• pp.115-115
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• 2002

• 소성∙가공
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• 제21권3호
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• pp.151-159
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• 2012

Finite element simulations were conducted to investigate the influence of grain growth in the superplastic blow forming process. A microstructure-based constitutive model considering grain growth effects is proposed and used in the simulations. Also, a grain growth rate equation accounting for both static and dynamic grain growth is implemented. The simulations were made using a 2D plane-strain model for constrained blow forming and an axisymmetric model for free bulging. These two models showed different features during the forming stages. However, the forming pressure-time curve and the thickness distribution obtained by both simulations explained well the deformation hardening induced by the grain growth during superplastic forming. This study shows that grain growth is an important factor in determining the material behavior during superplastic deformation.

• Journal of Mechanical Science and Technology
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• 제16권10호
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• pp.1246-1252
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• 2002

Ultrafine grained (UFG) low carbon (0.15 wt.% C) steel produced by equal channel angula. pressing (ECAP) was tested for investigating the effect of load ratio on the fatigue crack growth rate. Fatigue crack growth resistance and threshold of UFG steel were lower than that of asreceived coarse grained steel. It was attributed to the less tortuous crack path. The UFG steel exhibited slightly higher crack growth rates and a lower △Kth with an increase of R ratio. The R ratio effect on crack growth rates and △Kth was basically indistinguishable at lower load ratio (R >0.3), compared to other alloys, which indicates that contribution of the crack closure vanishes. The crack growth rate curve for UFG steel exhibited a longer linear extension to the lower growth rate regime than that for the coarse grained as-received steel.