• Bulletin of the Korean Chemical Society
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• v.24 no.6
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• pp.812-816
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• 2003

Accurate ab initio computational chemistry has evolved dramatically. In particular, the development of multireference-based approaches has opened up a completely new area, and has had a profound impact on the potential of theoretical chemistry. Multireference-based perturbation theory (MRPT) is an extension of the closed-shell single reference Møller-Plesset method, and has been successfully applied to many chemical and spectroscopic problems. MRPT has established itself as an efficient technique for treating nondynamical and dynamical correlations. Usually, a complete active space self-consistent field (CASSCF) wave function is chosen as a reference function of MRPT. However, CASSCF often generates too many configurations, and the size of the active space can outgrow the capacity of the present technology. Many attempts have been proposed to reduce the dimension of CASSCF and to widen the range of applications of MRPT. This review focuses on our recent development in MRPT.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2019.11a
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• pp.259-260
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• 2019

MPEG-I Visual group is actively working on enhancing immersive experiences with up to six degree of freedom (6DoF). In virtual space of 3DoF+, which is defined as an extension of 360 video with limited changes of the view position in a sitting position, looking at the scene from another viewpoint (another position in space) requires rendering additional viewpoints using multiple videos taken at the different locations at the same time. In the MPEG-I Visual workgroup, methods of efficient coding and transmission of 3DoF+ video are being studied, and they released Test Model for Immersive Media (TMIV) recently. This paper presents the enhanced clustering method which can pack the patches into atlas efficiently in TMIV. The experimental results show that the proposed method achieves significant BD-rate reduction in terms of various end-to-end evaluation methods.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.11 no.1
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• pp.25-32
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• 2011

In this paper, we study the existence and uniqueness of solutions for the impulsive semilinear fuzzy integrodifferential equations with nonlocal conditions and forcing term with memory in n-dimensional fuzzy vector space ($E^n_N$, $d_{\varepsilon}$) by using Banach fixed point theorem. That is an extension of the result of Kwun et al. [9] to impulsive system.

• The Pure and Applied Mathematics
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• v.10 no.4
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• pp.217-223
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• 2003

Let $\cal{K}$ be the extension Hilbert space of a Hilbert space $\cal{H}$ and let $\Phi$ be the faithful $\ast$-representation of $\cal{B}(\cal{H})$ on $\cal{k}$. In this paper, we show that if T is an irreducible ${\omega}-hyponormal$ operators such that $ker(T)\;{\subset}\;ker(T^{*})$ and $T^{*}T\;-\;TT^{\ast}$ is compact, then $\sigma_{e}(T)\;=\;\sigma_{e}(\Phi(T))$.

• Communications of the Korean Mathematical Society
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• v.28 no.2
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• pp.285-295
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• 2013

In this note we present sufficient conditions for the existence of Radon-Nikodym derivatives (RND) of operator valued measures with respect to scalar measures. The RND is characterized by the Bochner integral in the strong operator topology of a strongly measurable operator valued function with respect to a nonnegative finite measure. Using this result we also obtain a characterization of compact sets in the space of operator valued measures. An extension of this result is also given using the theory of Pettis integral. These results have interesting applications in the study of evolution equations on Banach spaces driven by operator valued measures as structural controls.

• Journal of Astronomy and Space Sciences
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• v.23 no.2
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• pp.135-142
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• 2006

The extension of sunspot number series and auroral observations backward in time is of considerable interest for dynamo theory, solar activity and climate research. It was known that the Maunder minimum corresponded to a unusual cold so called little ice age in Europe and the appearance of sunspot had a close relation to the occurrence of aurora. Therefore we have examined ancient records of sunspots and aurorae with indirect solar proxies during this period and have studied for the features and peculiarities of solar activity with the relation of the climate variation.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.2
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• pp.135-144
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• 1995

조립작업에 있어서의 경로계획(path planning)에 대하여 지금까지 많은 연구가 진행되어 왔으며, 그것의 주종을 이루는 것들은 cell decomposition 방식과 potential field 방식이다. 이러한 방식들은 free space를 세분하거나 potential field를 계산하는데 많은 시간을 필요로 하며, 조립부품 이동영역이 configuration space로 먼저 치환이 되어야 하는 문제점들이 발생하게 된다. 그러므로, 만약에 조립부품에 대한 이동환경이 복잡하지 않고 알려져 있으면 위의 방식들은 비용적인 면에서 많은 낭비를 가져온다. 본 논문에서는 간단하면서도 알려진 작업환경에서 효과적인 조립부품의 경로계획 알고리즘을 개발하였다. 먼저, channel, junction 및 간격 유지계수(clearance gap)의 개념을 도입하고, 이 개념들을 이용하여 룰 방식의 알고리즘을 개발하였다. 그리고, 이 알고리즘을 이동용 로봇의 경로계획에도 적용될 수 있음을 보였다.

• Journal of KIISE:Databases
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• v.27 no.1
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• pp.129-140
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• 2000

We propose the ARIES/RL which extends the with 're-logging' technique to manage the limited online 1og space efficiently even though 1ong-duration transactions exist. Re-logging isa technique that log records used in transaction rollback and restart recovery are copied forward in the log whenever the online log is not sufficient for keeping logs of on-going transactions It does not hurt the advantages of ARIES. Moreover, it handles log space efficiently in executing long-duration transactions. We also present the evaluation result of ARIES/RL and show that ARIES/RL handles online log efficiently.

• International Journal of Aeronautical and Space Sciences
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• v.4 no.1
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• pp.99-109
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• 2003

Attitude control law synthesis for the three-axis attitude maneuver of a flexible spacecraft model is presented in this study. The basic idea is motivated by previous works for the extension into a more general case. The new case includes gravitational gradient torque which has significant effect on a wide range of low earth orbit missions. As the first step, the fully nonlinear dynamic equations of motion are derived including gravitational gradient. The control law design based upon the Lyapunov approach is attempted. The Lyapunov function consists of a weighted combination of system kinetic and potential energy. Then, a set of stabilizing control law is derived from the basic Lyapunov stability theory. The new control law is therefore in a general form partially validating the previous work in some sense.

• Journal of architectural history
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• v.7 no.2 s.15
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• pp.113-126
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• 1998

This study is on the organizational principles of Chinese traditional houses. It has been assumed that a common cultural background did influence dwelling construction in most areas of China, some specific concepts are used to build a connection between the culture and architecture. There are four aspects of cultural influence being explored: traditional concept of space by the philosophical influence, religious influence, the Feng Shut method, and traditional system of family organization. The influence of the Chinese culture on dwelling architecture is predominant. Housing types from different areas of China, despite their different physical appearance, have similar spatial concepts. This cultural influence was due to the historic development of the Chinese empire. The organizational principles of Chinese dwelling architecture determined by its own cultural background have five major invariable norms. They are as follows: 1. Internal and enclosed spatial organization. 2. Grouping of buildings around axes. 3. Spatial organization and extension by courtyard. 4. Spatial expansion by adding units. 5. Hierarchical organization of space.