• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.178-178
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• 2008

This paper presents an efficient approach for simulating the loss of the laminated core joints in power transformers. Two laminated core models, with the same material and joint type but different leg length, are established for validating the specific total loss inside the joint region.

• Journal of Technology Innovation
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• v.15 no.2
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• pp.123-152
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• 2007

The striking characteristic of the contemporary global security environment is that the nature of threats has become diverse and complex. For example, transnational and non-military threats including terrorism and proliferation of weapon of mass destruction has increased. In this security environment, Advanced countries funnel their investments for defense budgets into the assurance of key force capability and R&D of cutting-edge core technologies, in consideration of future battlefield environments so as to get an edge on not only defense science and technology but also intelligence capabilities. As shown by past practices of the korea's defense acquisition, the ministry of national defense has tried to enhance its force capabilities in the short-term by purchasing foreign weapon systems rather than by investing in domestic R&D. Accordingly, the technological gaps between the korea and advanced countries were widened due to both insufficient investment in development of domestic technologies and avoidance of technological transfer by advanced countries. Thus, for the effective execution of the R&D budget and the successful performance of the projects, the importance of selection, management and evaluation of the R&D projects is emphasized. So, The objective of this study is that the analysis of the proposal-selection evaluation system for the realization of the successful defense core technology R&D projects. This study focused on the improvement of the proposal-selection evaluation model which can be applicable to the national defense core R&D projects. Using the improved proposal-selection evaluation system, we propose a model to enhance the reliability of the national defense core technology R&D project evaluation system.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.1320-1323
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• 2002

This paper reviews the Korean government’s selection process of core wireless communications technologies, and presents technology trends, perspectives and strategies of 5 core technologies to develop in wireless communications areas based on the mid term IT technology development plan(2002∼2004). Delphi Panel Method and Analytic Hierarchy Process(AHP) Analysis were adapted to select 30 core technologies in 9 strategic areas. Especially, 5 core wireless communications technologies out of 24 required technologies are selected: 4 G Core Technology, Broadband Wireless Access Network Technology, IMT-2000 Plus STP Technology, OBP Based Multimedia Satellite Communications Technology, Stratosphere Communications System Technology. Strategic national IT R&D program has been essential to continue success story of CDMA technology, and acquiring technology independency from advanced nations. In long term perspectives, a strategy of intensive investment with prudent selection onto core technologies should be deployed in the IT R&D programs. Also, the national IT R&D programs should be limited in the high risk & high returen areas where only government can afford the failures as well as better spill over effects are expected for the technology development and national economy. Korean industry has some strength in wireless communications technology area. Therefore, more policy concerns should be given into this area not only to secure present strength but also to explore better technology competitiveness.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1183-1184
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• 2006

Core loss of soft magnetic powder cores have been focused on to achieve high efficiency of power supplies. In this study the effects of crystal grain size on core loss were investigated by changing heat treatment conditions. It was found that core loss is influenced by crystal grain size because eddy current loss decreased and hysteresis loss increased by making crystal grain size smaller, and it is also influenced by particle size.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.351-361
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• 2019

The purpose of this study was to investigate the effect of a peer evaluation method on the core fundamental nursing skills competency, learning attitude, critical thinking and self-leadership of graduating nursing students. A survey using a questionnaire was administered to 326 nursing students. The data was analyzed using SAS(ver. 9.8) and AMOS(ver.20.0) The results of peer evaluation showed that the fundamental nursing skills competency was 3.77(${\pm}.62$), the learning attitude was 3.17(${\pm}.47$), critical thinking was 3.44(${\pm}.41$) and self-leadership was 3.60(${\pm}.49$). Core fundamental nursing skills competency showed statistical differences based on gender, major satisfaction, practice satisfaction, pre-learning and satisfaction with the peer evaluation. Core fundamental nursing skills competency was positively correlated with learning attitude(r=.295, p<.001), critical thinking was positively correlated with core fundamental nursing skills competency(r=.384, p<.001) and learning attitude(r=.623, p<.001), and finally, self-leadership was positively correlated with core fundamental nursing skills competency(r=.353, p<.001), learning attitude(r=.529, p<.001) and critical thinking(r=.690, p<.001). The factors affecting fundamental nursing skills competency were critical thinking and self-leadership. Core fundamental practical education programs to improve learning attitude, critical thinking and self-leadership need to be developed to increase core fundamental nursing skills.

• Design & Manufacturing
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• v.2 no.3
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• pp.16-21
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• 2008

In recent, the demands of household cases and disposable products is increased significantly because a living standard of newly-emerging nations was risen. Therefore, multi-cavity mold and stack mold for the realization of high-productivity have been researched in forefront nations. In this paper, CAE analysis for minimizing the mold core deformation was performed. Finally, 64 cavities injection mold for molding cap which has the insert-type core was fabricated according to the result of CAE analysis.

• Journal of Korea Foundry Society
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• v.33 no.4
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• pp.147-156
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• 2013

The effects of core materials on the microstructure and mechanical properties of Al casting products have been investigated. The Al casting samples and cylinder head were fabricated by using organic and inorganic binder core respectively, and their microstructure and mechanical properties were evaluated. The Al casting samples fabricated by using inorganic core showed the better mechanical properties such as tensile strength and elongation than those of the Al casting samples fabricated by using organic core. That's because the Al casting samples contained small amount of pore defects and had fine microstructure compared with the Al casting samples fabricated by using organic core. Also, the use of inorganic core effectively reduced harmful gas emission and pollution.

• Journal of the Korean Society for information Management
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• v.15 no.2
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• pp.137-162
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• 1998

The purpose of this paper is to present core elements of bibliographic records to effective cataloging a variety of information materials such as monographs, non-book materials, serials, and internet resources. At first, AACR2R bibliographic data elements, the minimal level cataloging, and core records proposed by Progrma for Cooperative Cataloging(PCC) in Library of congress are discussed. After that elements of Core Records, dublin Core, KORMARC, and AACR2R are compared. Upon the results, this study suggests mandatory common core elements and optional core elements for cost-effective cataloging to all kinds of documents including internet resources.

• Applied Chemistry for Engineering
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• v.7 no.4
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• pp.809-812
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• 1996

Generalized van der Waals equation of state combined with the core-softening theory and temperature dependent repulsive and attractive terms exhibit the anomalous thermal expansion, i.e. density anomaly. Density maxima occur at both positive and negative pressure when the hard-core diameter decreases with increasing temperature, $db_r/dT_r<0$, and at negative pressure when the repulsive force increases with increasing temperature, $da_r/dT_r>0$.

• ETRI Journal
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• v.25 no.5
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• pp.337-344
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• 2003

In this paper, we introduce a fully synthesizable 32-bit embedded microprocessor core called the AE32000B. The AE32000B core is based on the extendable instruction set computer architecture, so it has high code density and a low memory access rate. In order to improve the performance of the core, we developed and adopted various design options, including the load extension register instruction (LERI) folding unit, a high performance multiply and accumulate (MAC) unit, various DSP units, and an efficient coprocessor interface. The instructions per cycle count of the Dhrystone 2.1 benchmark for the designed core is about 0.86. We verified the synthesizability and the area and time performances of our design using two CMOS standard cell libraries: a 0.35-${\mu}m$ library and a 0.18-${\mu}m$ library. With the 0.35-${\mu}m$ library, the core can be synthesized with about 47,000 gates and operate at 70 MHz or higher, while it can be synthesized with about 53,000 gates and operate at 120 MHz or higher with the 0.18-${\mu}m$ library.