• Publications of The Korean Astronomical Society
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• v.32 no.1
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• pp.59-61
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• 2017

The AKARI 9 and 18 µm diffuse maps reveal the all-sky distribution of the interstellar medium with relatively high spatial resolution of ~6". The zodiacal light is a dominant foreground component in the mid-infrared. Thus, removal of the zodiacal light is a critical issue to study low surface brightness Galactic diffuse emission. We carried out modeling of the zodiacal light based on the Kelsall model which is constructed from the COBE data. In the previous study, only a time-varying component of the zodiacal light brightness was used for determination of the model parameters. However, there remains a residual component of the zodiacal light around the ecliptic plane even after removal with the model. Therefore, instead of using a time-varying component, we use the absolute brightness of the zodiacal light and we find that the new model can better remove the residual component. As a result, the best-fit model parameters are changed from those in the previous study. We discuss the properties of the zodiacal light based on our new result.

• Nuclear Engineering and Technology
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• v.52 no.1
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• pp.59-68
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• 2020

ECCMIX component was introduced in RELAP5/MOD3 for calculating the interfacial condensation. Compared to other existing components in RELAP5, user experience of ECCMIX component is restricted to developmental assessment applications. To evaluate the capability of the ECCMIX component, ECCS experiment was conducted which included single-phase and two-phase thermal mixing. The experiment was carried out with test sections containing a main pipe (70 mm inner diameter) and a branch pipe (21 mm inner diameter) under the atmospheric pressure. The steam mass flow in the main pipe ranged from 0 to 0.0347 kg/s, and the subcooled water mass flow in the branch pipe ranged from 0.0278 to 0.1389 kg/s. The comparison of the experimental data with the calculation results illuminated that although the ECCMIX component was more difficult to converge than Branch component, it was a more appropriate manner to simulate interfacial condensation under two-phase thermal mixing circumstance, while the two components had no differences under single-phase circumstance.

• ETRI Journal
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• v.31 no.3
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• pp.304-314
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• 2009

Component-based software reuse has been generally regarded as a promising approach to improving software productivity and quality within software development. However, progress in component-based software reuse has been slower than expected. Much of the software reuse literature points to the lack of software components that can maximize users' benefits as the most important source of the slow progress. Considering that the underlying processes behind component-based software reuse are strikingly similar to commercial software marketing, this paper attempts to identify the aspects of software components that consumers value and to establish relationships between the identified aspects and consumer behavior in the software component market. More specifically, this paper focuses on the perceived subjective features of software components. This study was conducted in a web-based artificial market environment called "SofTrade."

• Bulletin of the Korean Mathematical Society
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• v.44 no.4
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• pp.795-806
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• 2007

We investigate F-traceless component of the conformal curvature tensor defined by (3.6) in $K\ddot{a}hler$ manifolds of dimension ${\geq}4$, and show that the F-traceless component is invariant under concircular change. In particular, we determine $K\ddot{a}hler$ manifolds with parallel F-traceless component and improve some theorems, provided in the previous paper([2]), which are concerned with the traceless component of the conformal curvature tensor and the spectrum of the Laplacian acting on $p(0{\leq}p{\leq}2)$-forms on the manifold by using the F-traceless component.

• Nuclear Engineering and Technology
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• v.54 no.8
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• pp.2974-2988
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• 2022

Implementation of component isolation in nuclear industry is challenging due to gaps in research and the lack of specific guidelines. In this study, parameters affecting component-level isolation of advanced reactor vessels are identified based on a representative numerical model with explicit consideration of nonlinear soil-structure interaction (SSI). The objective of this study is to evaluate the effectiveness of, and to identify potential limitations of using conventional friction pendulum bearings to seismically isolate vessels. It is found that slender vessels or components are particularly vulnerable to rotational accelerations at the isolation interface, which are caused by rotation of the sub-structure and by excitation of higher modes in the horizontal direction of the seismically isolated system. Component isolation is found to be more effective for relatively stiffer vessels and at sites with stiff soil. Considering that conventional isolators are deficient in resisting axial tension, it is observed that the optimum location for supporting a component to achieve seismic isolation, is at a cross-sectional plane passing through the center of mass of the vessel. These findings are corroborated by numerous simulations of the response of seismically isolated reactor vessels at different nuclear power plant sites subject to a variety of ground motions.

• Journal of Power Electronics
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• v.19 no.4
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• pp.1045-1053
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• 2019

A symmetrical component decomposition scheme utilizing the characteristics of the asynchronous rotational reference frame transformation is proposed in this paper for the extraction of the positive and negative sequence components of distorted three-phase grid voltages. The undesired frequency component can be removed using a specially designed series coordinate transformation and half-cycle delays, where the delay can be controlled by adjusting the frequency of the rotating reference frame. The extracted symmetrical component can then be compensated based on the applied coordinated transformation. The dynamic response of the proposed algorithm is improved when compared to that of conventional methods. The effectiveness of the proposed algorithm is verified by simulation and experimental results.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.864-865
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• 2006

Alumina microcomponents have distinguishing advantages over Si counterpart. However, the shrinkage of alumina, as high as 20%, makes it difficult to produce precision components meeting a high tolerance. A new fabrication process presented to greatly reduce the shrinkage by producing alumina microcomponents from ultrafine Al powder. The process consists of forming Al powder components through sintering and turning the Al powder component into alumina. In this way, the shrinkage occurring in sintering the Al powder component will be compensated by the expansion appearing when the Al powder component turns into alumina. The process has proven successful.

• Journal of Korean Elementary Science Education
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• v.32 no.4
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• pp.379-392
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• 2013

The purpose of this study was to examine the effects of animation-based instruction on elementary students' level of understanding and interest on a plant's structure and function, using "Magic School Bus(Joanna Cole, Bruce Degen, 1986)". The understanding and interest measurements were administered to 99 fifth grade students at a elementary school located in Seoul. The study examined the changes in understanding and interest through pre-test and post-test of the two groups. Intensive interviews were conducted to find factors that enhance understanding and interest. Three key findings were revealed from the results. First, the animation-based instruction enhanced the level of understanding in the experimental group compared to the control group. Second, animation-based instruction made high-achieving students enhance their interest in topic component and attitude component. And, animation-based instruction did not led low-achieving students to increase their interest in the topic component and attitude component. We suggest that animation-based instruction positively influences students' understanding, but its effects on students' interest are dependent on their conceptual understanding of the topic.

• Journal of the Korean Data and Information Science Society
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• v.13 no.1
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• pp.17-23
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• 2002

Microsoft's component technology, COM, is introduced and a COM object for generating distribution numbers is implement ed. Examples using the object in various language environments are given. A strategy for statistical software development using components is discussed.

• Macromolecular Research
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• v.16 no.7
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• pp.663-665
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• 2008