• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4757-4761
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• 2012

LED chip on board(COB) package has been fabricated using aluminum substrate and aluminum anodization process. An alumina layer, used as a dielectric in COB substrate, is produced on aluminum substrate by selective anodization process. Also, selective anodization process makes it possible to construct a thermal via with a fully-filled via hole. Two types of the COB package are fabricated in order to analyze the effects of their substrate types on thermal resistivity and luminous efficiency. The aluminum substrate with the thermal via shows more improved measurement results compared with the alumina substrate. These results demonstrate that selective anodization process and thermal via can increase heat dissipation of COB package in this work. In addition, it is proved experimentally that these parameters also can be enhanced using efficient layout of multiple chip in the COB package.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.05a
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• pp.23-28
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• 2002

This paper describes the machining characteristics of the $MoSi_2$ based composites by electric discharge drilling with various tubular electrodes, besides, Hardness characteristics and microstructures of $Nb/MoSi_2$ laminate composites were evaluated from the variation of fabricating conditions such as preparation temperature, applied pressure and pressure holding time. $MoSi_2$ -based composites has been developed in new materials for jet engine of supersonic-speed airplanes and gas turbine for high- temperature generator. Achieving this objective may require new hard materials with high strength and high temperature-resistance. However, With the exception of grinding, traditional machining methods are not applicable to these new materials. Electric discharge machining (EDM) is a thermal process that utilizes a spark discharge to melt a conductive material, the tool electrode being almost non-unloaded, because there is no direct contact between the tool electrode and the workpiece. By combining a nonconducting ceramics with more conducting ceramic it was possible to raise the electrical conductivity. From experimental results, it was found that the lamination from Nb sheet and $MoSi_2$ powder was an excellent strategy to improve hardness characteristics of monolithic $MoSi_2$. However, interfacial reaction products like (Nb, Mo)$SiO_2$ and $Nb_2Si_3$ formed at the interface of $Nb/MoSi_2$ and increased with fabricating temperature. $MoSi_2$ composites which a hole drilling was not possible by the conventional machining process, enhanced the capacity of ED-drilling by adding $NbSi_2$ relative to that of SiC or $ZrO_2$ reinforcements.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.3
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• pp.697-707
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• 2015

This paper covered the design and implementation of the demodulation receiver in the ADS-B 1090ES system, which is one of the CNS/ATM's surveillance systems. This researched demodulation performed at the level required by RTCA DO-268B and EUROCAE ED-129. The single signal process method, which applies a baseline multi-sample technique among multi-amplitude sample demodulations, was suggested to improve the quality of the receiver signal, the dynamic range and so on. The suggested multi-signal level tuning method has enhanced the single-signal process method, reducing the unstable reception ratio by the transmit output level difference and manufacturing receiver hardware. The result was that the receiver suggested by the method had 0~87dBm in dynamic range and -90dBm in MTL. This shows a better performance by -3dBm less than the international standard in ADS-B 1090ES ground receiver equipment. The systems which use a similar modulation method, will be considered to be widely applied.

• Transactions of the KSME C: Technology and Education
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• v.1 no.1
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• pp.69-73
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• 2013

This study is about the secondary concentration technology using electrodialysis process for minimum discharge and maximize recovery ratio from seawater desalination by reverse osmosis process. The experimental method adopted the constant voltage driving method and, concentrated/desalination volume capacity ratio changes, voltage changes and electrolyte types. Multi-ion membrane is used, aiming to derive conditions to minimize the TDS concentration of desalination water, to minimize the volumes of secnodary concentraion water and minimizing the power efficiency. The results of this study are as follows. The optimal ratio of concentraion/desalination volume is 1:5, the final TDS concentration of desalinated water is 5.32g/l, the final secnodary concentrated water salinity is 17.07% and electric energy demands of desalinated water is $16.74kWh/m^3$.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.11a
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• pp.571-574
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• 2006

2006년 5월 국제전기기술위원회(International Electrotechnical Commission, IEC) TC62(의료용전기기기기술위원회) SC62A(의료용전기기기 공통특성에 관한 세부분과위원회)에서 의료기기 소프트웨어의 생명주기 프로세스에 관한 국제규격인 IEC 62304, Ed.1을 제정하였다. 전체 내용은 크게 일반적인 요구사항(General requirements)과 소프트웨어 개발과 유지보수에 대한 프로세스(Software development & maintenance process)로 구성되어 있다. 그리고 소프트웨어 개발과 유지보수 프로세스가 진행되는 동안에 기본적으로 확보되어야 하는 소프트웨어 위험관리와 형상관리에 대한 프로세스 Software risk management & configuration management process)를 규정하고, 또한 문제 발생 시 이를 해결하기 위한 소프트웨어 문제 해결 프로세스(Software problem resolution process)를 규정하고 있다. 이는 기존의 정보통신 분야에서 사용되던 소프트웨어 생명주기 프로세스인 ISO/IEC 12207 규격과 외형상 많은 차이를 나타내고 있다. 이에 본 논문에서는 의료기기 소프트웨어의 생명주기 프로세스에 관한 국제규격인 IEC 652304를 분석하여 실제 의료용 소프트웨어 개발 및 유지보수 작업들이 어떠한 방식으로 이루어지는지를 분석하고, 또한 기존의 소프트웨어 생명주기 프로세스인 ISO/IEC 12207 규격과의 차이점을 비교 분석하여 본 규격에 대한 근본적인 활용 방안을 모색하고자 한다.

• Animal cells and systems
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• v.1 no.2
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• pp.341-344
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• 1997

Receptor-mediated endocytosis has been suggested for a stage-specific transport mechanism of vitellogenin into the oocytes of a sabellid poly chaete, Pseudopotamilla occelata. Membrane proteins of oocytes of three size classes, including small (30-70 $\mu\textrm{m}$ in diameter), intermediate (70-140 $\mu\textrm{m}$ in diameter) and large (180-200 $\mu\textrm{m}$ in diameter), showed a atage-specific variation. Coelomic fluid proteins (CP), ass$\mu\textrm{m}$ed to be vitellogenin, consists of several proteins, which showed quite a different pattern from that of yolk proteins. Incorporation of $^{125}I$-CP into the oocytes of the intermediate size class almost linearly increases with time, showing a contrast to the pattern of the large size class, in which the incorporation is low and approaches a plateau, suggesting the vitellogenin transports by a regulated process only in the intermediate size class. Vitellogenin receptor proteins were identified to be 60 kDa and 68 kDa only in the intermediate size class by a ligand blotting test.

• Journal of the Korean Chemical Society
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• v.53 no.4
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• pp.422-426
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• 2009

An efficient, chemoselective and practical protocol for N-Boc protection of amines using di-tertbutoxypyrocarbonate $(Boc)_{2}O$ in presence of Indion 190 resin. Resin was easily separated from the reaction mixture by filtration and reused in subsequent reactions without any apparent loss of activity. Simple workup, mild condition, short reaction time and high yield are some of the striking features of the present process.

• Convergence Security Journal
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• v.14 no.6_1
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• pp.33-43
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• 2014

In this study, diagnosis of the problem of self-directed learning for the improvement of the language, reasoning n eeded for NCOs typical for students currently enrolled as a cadet NCOs and suggested some lessons to improve this model. Proposed presentation, the three curriculum of presentation and discussion related to the configuration intervie w, self-directed learning was to be his students. In one of the ways to solve the problems experienced in a self-pac ed learning learner was used in this process is often the scaffolding system, is shown that can lead to improved abil ity to apply the result of expression of the three class model.

• The Journal of Korea CHUNA Manual Medicine
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• v.5 no.1
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• pp.135-139
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• 2004

Objectives : The objectives of this report is to introduce PTA. Methods : The examination of the leg length inequality gives us a useful tool for diagnosis of body imbalance. especially pelvic distortion. There are four steps in the process of the leg analysis, according to "The Standard Manual of Chuna Society (2nd ed., Seoul:KCA Press. 2001)". In the last step of the analysis, knee-flexing over $90^{\circ}$, we have often experienced a specific sign that the lower legs are attracted toward one side spontaneously. The authors call it 'Lower Leg Lateral Attraction'. This is a very significant sign that gives us which is the major part between pelvis and the upper parts over sacrum. Thus it is definded as "Pelvic Twist Analysis, PTA" by the authors. With PTA, first, you must check the side of short leg and next, check the side of lateral attraction in lower leg over-flexing. If both sides coincide with each other, then the major part you can correct first is pelvic distortion. If not, you must find another part for primary correction, instead of pelvis. Conclusions : PTA becomes a useful complement to the examination of the leg length inequality.

• Journal of Technology Innovation
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• v.13 no.1
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• pp.247-263
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• 2005

Prior research in R8ED innovation in Korea has been centered around the 'three-stage development model,' which hypothesizes that the Korean innovation process goes from the introduction (of foreign technology) stage, through assimilation stage to the final modification stage. As Korean economy shifts from traditional industry-led development to innovation-centric development, such an approach loses sight of the whole picture. The current study argues that a new framework is required for adequate analysis on newly arising innovative patterns in Korea, emphasizing source technology development and technology leader strategy. For this purpose, we propose the 'Jigsaw Puzzle Model' of technology development, which is then verified by an in-depth analysis on the innovation processes of 3 representative IT products of Korea, DRAM, TH LCD, and CDMA. The model suggests that Korean innovation model is a dynamic, efficient amalgamation of foreign-acquired and dependent technologies, based on internally accumulated technological resources. The model explains better how Korean firms are achieving a rapid catch-up of technological gaps with advanced nations and are able to transfer from the technology follower to the leader position.