• Electrical & Electronic Materials
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• v.10 no.8
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• pp.813-818
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• 1997

In this study the thin film air core and magnetic core inductors consisting of planar coil and/or CoNbZr amorphous magnetic layers on a Si substrate were fabricated as spiral type by using rf magnetron sputtering and wet etching methods. The etchant solution was achieved by iron chloride solution(17.5 mol%) mixed with HF (20 mol%) during 150 sec which etched Cu films and CoNbZr/Cu/CoNbZr multi-layer films. They were about 10${\mu}{\textrm}{m}$ of thickness and 10$\times$10 mm$^2$of size. The properties of thin film magnetic core inductor were 400 nH of Q value at 10 MHz and the resonance frequency was about 300 MHz.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1284-1285
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• 2006

We reported a P/M soft magnetic material with core loss value of $W_{10/1k}=68W/kg$, which is lower than that of 0.35mm-thick laminated material, by using high purity gas-atomized iron powder. Lack of mechanical strength and high cost of powder production are significant issues for industrial use. In order to achieve both low core loss and high strength by using inexpencive powder, the improvement of powder shape and surface morphology and binder strength was conducted. As the result, the material based on water-atomized powder with 80 MPa of TRS and 108 W/kg of core loss (W10/1k) was achieved.

• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.217-218
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• 2015

Two axial flux permanent magnet (AFPM) machines using soft magnetic composite (SMC) and lamination steel are studied. Generally stator cores of AFPM machines are manufactured using SMC because AFPM machines need 3 dimensional core structures. However, SMC cores have very disadvantages in magnetic properties. Especially permeability value is much lower than that of lamination steel, so magnetic field density is also lower. In terms of core losses, SMC cores have much larger loss values than lamination steel cores because SMC core can't be laminated. In this study, AFPM machine was designed using laminated steel, and iron losses in two machines using SMC and laminated steel were studied. Simulations were carried out by a commercial 3-D FEM tool.

• Electronics and Telecommunications Trends
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• v.39 no.3
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• pp.13-24
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• 2024

The capabilities of the metaverse have been demonstrated by representative examples such as Roblox, Fortnite, and Zepeto, and it can enable gaming, social networking services, and other applications. Nevertheless, research on the metaverse has been fragmented owing to conflicting definitions, core values, and characteristics. This ambiguity in metaverse conventions has hindered related research, analysis, and policy establishment. As the confusion seems to aggravate, consistent concepts should be established. Although the coronavirus disease pandemic led to a collapse in metaverse usage, it is regaining public interest since 2022. To promote the metaverse development, we structure core values based on existing research and surveys of consumer expectations. We found that consumers perceive the metaverse as a realistic virtual space and a potential economic opportunity. Hence, it seems necessary to track the extent to which the metaverse core values satisfy consumer demands. Such core values should be consistently reflected in policies and technology development.

• The Journal of Korean Academy of Prosthodontics
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• v.39 no.2
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• pp.197-207
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• 2001

Development of new ceramics and esthetic needs of patients increase the use of all ceramic restorations. Fractured teeth often need metal post and core as foundation for final restoration. When all ceramic restorations are planned, metal post and core may lead to compromised esthetics because of opacity and gray color of metal post and core. Many techniques have been proposed to solve this problem such as application of an opaque porcelain to the metal core or all ceramic post and core. This study was performed to evaluate effect on color of Empress 2 crown according to various post systems. Color was evaluated by the CIE $L^*a^*b^*$ systems and measured by spectrophotometer (Model CM-3500, Minolta, Japan). Specimens were divided into 4 groups as follows Group 1 : gold cast post specimen + Empress 2 crown specimen Group 2 : application of an opaque porcelain to gold cast post specimen + Empress 2 crown specimen Group 3 : cosmopost specimen + Empress 2 crown specimen Group 4 : In-ceram post specimen + Empress 2 crown specimen. The results obtained as follows, 1. $L^*$ Values showed that group 2, 3, 4 were higher than group 1 with significant difference and group 2, 3, 4 were not significantly different. 2. $a^*$ Values and $b^*$ values also showed that group 2. 3, 4 were higher than group 1 with significant difference and group 2, 3, 4 were not significantly different. 3. ${\Delta}E^* ab$ Values showed that ${\Delta}E^* ab$ 3 was the highest value and ${\Delta}E^* ab$ 5 was the lowest value.

• Journal of the Korean Wood Science and Technology
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• v.48 no.5
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• pp.608-617
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• 2020

For efficient use and expansion of domestic small- and medium-diameter woods, cross-laminated wood panels composed of tropical hardwoods and domestic temperate woods were fabricated, and the bending creep behavior under long-term loading was investigated. The bending creep curve of the cross-laminated wood panels showed an exponential function graph with a sharp increase at the top right side. The wood panel composed of a teak top layer and larch core and bottom layers recorded the highest initial deformation, and that composed of a merbau top layer and tulip core and bottom layers showed the lowest initial deformation. Creep deformation of the cross-laminated wood panels showed the highest value in that composed of a teak top layer and larch core and bottom layers and showed the lowest value in that composed of a merbau top layer and tulip core and bottom layers. The obtained creep deformation is 3.1-4.3 times that of merbau, however, it is remarkably lower than that of tulip and larch. The highest relative creep was recorded by the wood panel composed of merbau top layer and larch core and bottom layers, whereas that composed of the teak top layer and tulip core and bottom layers showed the lowest relative creep.

• International Journal of Quality Innovation
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• v.7 no.3
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• pp.82-91
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• 2006

In order to achieve sustainable growth in the era of global competitiveness, a speedy and flexible strategy is needed in the fast changing management environment. For this purpose, strengthening the core confidence in the organization along with acquiring competitive advantages that cannot be easily copied by competitors should be done based on dealing with needs from customers and markets positively. In this study, the creative value innovation strategy and creative value design methodology will be presented to improve company competitiveness.

• Restorative Dentistry and Endodontics
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• v.21 no.1
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• pp.70-86
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• 1996

The purpose of this study was to analyze the stress distribution in mandibular second premolars restored with different post and core techniques. Sixteen two-dimensional finite element model of mandibular second premolars restored with post and core and complete crown were developed according to the diameter, length, and material of post and core. Vertical force, 10N in magnitude, was applied first to the central fossa and then $45^{\circ}$ oblique force of same magnitude was applied to the buccal contact surface of buccal cusp. The obtained results were as follows : 1. Stress distribution within the dentin 1) Regardless of the material of the post and core and the diameter and length of the post, the pattern of stress distribution within the dentin was similar. 2) Maximum dentinal stress was observed on the lingual root surface of alveolar crest level with oblique loading and on lingual side of root dentin at the crown margin on vertical loading. 3) Cast post and cores produced the lowest dentinal stress concentrations and the highest stress concentration was observed in composite resin post and cores. 2. Stress distribution within the post and core 1) Within the amalgam and composite resin post and core, the patterns and maximum values of stress were similar. Maximum stress located at the central fossa of core portion on vertical loading and at the lingual junction of post and core with oblique loading. 2) Among the all post and cores, the cast post and core registered the highest stress concentration and maximum stress value within the post. Maximum stress located at the post apex on vertical loading and at lingual half of the post surface with oblique loading. 3) In case of Para-post and amalgam core, maximum stress located at the central fossa of core portion and lingual tip of the post head on vertical loading. With oblique loading, maximum stress located at the lingual half of the post surface.

• Journal of Korea Society of Industrial Information Systems
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• v.15 no.1
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• pp.15-23
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• 2010

This paper presents a method of constructing a large interlinked ontology network for the Web of Data through the mapping among typical ontologies. When an ontology is open to the public, and more easily shared and used by people, its value is increased more and more. By linking CoreOnto, an IT core ontology constructed in Korea, to the worldwide ontology network, CoreOnto can be open to abroad and enhanced its usability. YAGO is an ontology constructed by combining category information of Wikipedia and taxonomy of WordNet, and used as the backbone of DBpedia, an ontology constructed by analyzing Wikipedia structure. So a mapping method is suggested by linking CoreOnto to YAGO and DBpedia through the synset of WordNet.

• Journal of the Korean Society for Library and Information Science
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• v.57 no.2
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• pp.123-150
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• 2023

This study aimed to propose the core values of librarians by investigating the core values of domestic and foreign libraries, including ALA's core values, and analyzing related research by domestic and foreign researchers. The research process included literature analysis, case studies, and surveys. The results showed that although the recognition of the need for setting core values for librarians was high (4.48), the awareness and understanding of core values were low. The reasons for recognizing the need for setting core values included improving the recognition and value of librarians, enhancing their professionalism, and establishing the value of libraries. The study proposed approximately 20 core values for librarians, with only two items scoring below 4 points, and 18 items showing high agreement with scores of 4 points or above. Particularly, professionalism, accessibility, diversity, service, literacy, and public interest all scored above 4.4. Analysis of perception differences between different types of libraries revealed significant differences for almost all items, with school libraries showing the most significant differences. The study recommends conducting in-depth research at the national level to reduce the number of core values to within 10 and share them with the nation.