• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.113-113
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• 1999

최근의 고품질 III-N 화합물 반도체 박막성장과 더불어 청색계열의 LED 및 LD의 성공적인 실현은 본 연구분야에 대한 새롭고 헌신적인 상업적, 학문적/ 기술적 투자환경을 유도해 나가고 있다. 특히, c-축 배향 단결정 사파이어를 기판재료로 사용하고 얇은 GaN buffer의 사용은 고온에서 그 위에 성장되는 성장박막의 특성을 크게 향상시키는 것으로 알려져 있다. 그러나 절연체를 기판으로 사용함에 따른 소자구조 및 제작공정의 복잡성과 기판과 GaN 박막사이의 큰 격자 부정합에 따른 결함센터 등은 소자의 전기, 광학적, 구조적 특성에 부정적인 영향을 미치고 있다. 이러한 문제점을 해결하고 양질의 박막을 성장하기 위한 GaN 혹은 그 대체 기판의 개발에 많은 연구투자가 이루어지고 있는 현실 속에서 Si을 기판으로 이용한 GaN 성장의 가능성이 조심스럽게 점쳐지고 있다. 현재까지의 연구결과를 참조할 때 대체로 복잡한 interlayer를 사용하여 박막성장이 일부 이루어졌으나 그 재현성이나 성장의 중요인자에 대한 해석은 아직 분명하게 밝혀져 있지 않다. 본 연구에서는 원자적 관점에서 Si의 표면에 일부 변화를 유도하고, MOCVD 방법으로 그 위에 성장되는 GaN 박막의 광학적 및 표면 morphology 등에 미치는 영향을 분석하여 핵심적인 성장인자를 추출하고자 시도하였다. 성장된 GaN/Si 박막의 물성은 SEM(AFM), PL, XRD, Auger depth profile 장비등을 이용하여 조사하였으며 사파이어 기판 위에 성장된 GaN 박막의 특성들과 비교 검토하였다.

• Composites Research
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• v.29 no.5
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• pp.315-320
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• 2016

Conventionally, composite aircraft structures are fabricated within autoclave at high pressure. However, autoclave process has several disadvantages including high curing costs and limitation of part size. Recently, out-of-autoclave (OoA) processes have been investigated in many studies to replace conventional autoclave process. A newly developed OoA prepreg, using conventional ovens, can significantly reduce the curing costs and produce autoclave-quality parts. Nevertheless, manufacture of void-free complex shape structure using OoA process presents significant challenges because of the low consolidation pressure. In this study, integrated skin-spar-rib composite part was fabricated using OoA prepreg. And cross-sectional macro- and micro-graphs of the part were examined in order to assess the possibility of replacing conventional autoclave process.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.635-638
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• 2018

The Cost for introducing smart factory will decrease and the service type will change from a large scale to small quantity manufacturing, when 3D printing technologies have actively applied and smart factory related technologies have more stably developed. If customers have to provide private information, the availability of developed technology may cause slow progress. We propose a new protocol for custom manufacturing service of smart factory. The proposed approach is designed for smart contract based IoT convergence network. We analyzed the requirements of the proposed approach which provides anonymity, privacy, fairness, and non-repudiation. We compared it with closely related studies to show originality and differences.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.2
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• pp.215-222
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• 2019

Advances in technologies about 3D (three-dimensional) printing and smart factory related issues will have the effect of reducing the cost of building a smart factory and making various types of service available. Manufacturers and service providers of small assets work with outside experts to provide small amounts of customized ordering services. If customers have to disclose their private information to subscribe to a new service, they may be reluctant to use it and the availability of developed technology may cause slow progress. We propose a new protocol for customized order service for smart factory. The proposed approach is designed to meet requirements of security and based on smart contract in IoT convergence network. We analyzed the requirements of the proposed approach which provided anonymity, privacy, fairness, and non-repudiation. We compared it with closely related studies to show originality and differences.

• The Journal of the Convergence on Culture Technology
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• v.9 no.5
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• pp.821-830
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• 2023

The advancement of Internet network technology has triggered the emergence of new OTT video content platforms, increasing demand for content and altering consumption patterns. This trend is bringing positive changes to the South Korean animation industry, where diverse and high-quality animation content is becoming increasingly important. As investment in technology grows, video production technology continues to advance. Specifically, 3D animation and VFX production technologies are enabling effects that were previously unthinkable, offering detailed and realistic graphics. The Fourth Industrial Revolution is providing new opportunities for this technological growth. The rise of Artificial Intelligence (AI) is automating repetitive tasks, thereby enhancing production efficiency and enabling innovations that go beyond traditional production methods. Cutting-edge technologies like 3D animation and VFX are being continually researched and are expected to be more actively integrated into the production process. Digital technology is also expanding the creative horizons for artists. The future of AI and advanced technologies holds boundless potential, and there is growing anticipation for how these will elevate the video content industry to new heights.

• Journal of Advanced Navigation Technology
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• v.13 no.6
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• pp.838-845
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• 2009

In order to obtain magneto-dielectrics with various permmittivity and permeability which could be used as the antenna substrate, various magneto-dielectrics compounded of dielectric materials(such as silicon and epoxy resin) and magnetic materials(such as carbonyl iron, barium and strontium powder) were fabricated. The relative permittivity and permeability of those were measured by use of HP 4291B impedance analyzer. Based upon the measured results, inverted-F meander monopole antennas(IFA) which were printed on the magneto-dielectric substrates fabricated as film type were designed and fabricated to investigate into variations of antenna characteristics such as the resonant frequency and impedance bandwidth in comparison with use of dielectric substrate. Some simulated and measured results for the designed IFA were presented. Characteristics of magneto-dielectrics which are different according as the choice of magnetic material or the composition ratio between magnetic material and dielectric material is different have been discussed.

• Journal of the Korean Magnetics Society
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• v.6 no.5
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• pp.317-322
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• 1996

Thin films of Fe-Zr-N were fabricated by rf magnetron reactive sputtering method. The saturation magnetization and coercivity as functions of annealing temperature and partial pressure of nitrogen gas, effective permeability at high frequencies, and thermal stability were investigated. Magnetic softness was exhibited in the composition range of $Fe_{72-78}Zr_{7-10}N_{15-18}$ which was boundary between polycrystalline and amorphous structure. These films exhibited magnetic softness with saturation magentic flux density of 1.55 T and effective permeability of about 3000 at 1 MHz. These films also exhibited thermal stability by sustaining effective permeability of 2500 or above as the temperature was raised to $550^{\circ}C$. It is asswned that good magnetic softness is obtained because grain growth of $\alpha-Fe$ is prohibited due to the precipitation of ZrN nanocrystals. The grain sizes of $\alpha-Fe$ films were $40~50\AA$ and the grain sizes of ZrN nanocrystals were $10~15\AA$.

• Journal of the Korean Magnetics Society
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• v.25 no.4
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• pp.129-137
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• 2015

The Cu(radius ra = $95{\mu}m$)/$Ni_{80}Fe_{20}$(outer radius $r_b$ = $120{\mu}m$) core/shell composite wire is fabricated by electrodeposition. The two diagonal components of impedance tensor for the Cu/$Ni_{80}Fe_{20}$ core/shell composite wire in cylindrical coordinates, $Z_{zz}$ and $Z_{{\theta}{\theta}}$, are measured as a function of frequency in 10 kHz~10 MHz and external static magnetic field in 0 Oe~200 Oe. The equations expressing the diagonal $Z_{zz}$ and $Z_{{\theta}{\theta}}$ in terms of diagonal components of complex permeability tensor, ${\mu}^*_{zz}$ and ${\mu}^*_{{\theta}{\theta}}$, are derived from Maxwell's equations. The real and imaginary parts of ${\mu}^*_{zz}$(f) and ${\mu}^*_{{\theta}{\theta}}$(f) spectra are extracted from the measured $Z_{zz}$(f) and $Z_{{\theta}{\theta}}$(f) spectra, respectively. It is presened that the extraction of ${\mu}^*_{zz}$(f) and ${\mu}^*_{{\theta}{\theta}}$(f) spectra from the diagonal impedance spectra can be a versatile tool to investigate dymanic magnetization process in the core/shell composite wire.

• The Journal of the Convergence on Culture Technology
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• v.4 no.3
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• pp.149-158
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• 2018

VR image content producers are now terrestrial broadcasters, movie studios, game companies, and VR content producers (productions). As the VR market begins to form, investment in VR image content production is also expanding. The terrestrial KBS 'Summter VR' has been produced steadily from 2016 to 2017. 2D and VR images were simultaneously broadcast. If we compare and analyze these two image data, we could get a meaningful presentation. In this paper, 'Summter VR' is analyzed by cutting the image by time. "Summter VR" was using a long take for an average of 30 seconds or more, and at the same time, it was choosing a beautiful place so as not to fall into the boredom of long take directing. Most of the images of 'SummterVR' were long take techniques using the mise en scene VR technique.

• The Journal of the Korea Contents Association
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• v.11 no.11
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• pp.137-144
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• 2011

This study explored the risk sharing mechanism in the US TV drama industry. The hollywood system of TV production and distribution can be understood to be the result of the efforts to reduce the uncertainty and the risk of investment. Since the 1990s, the vertical integration of major studios and networks has been one of the core strategies for risk sharing. In the strategy, the most important role of networks is to schedule new series that the affiliated studios produce. Networks also provide the new series their brand value. On the other hand, the most important role of studios in the vertical integrated environment is to provide the affiliated networks the infrastructures for production and distribution, financial management, and product management. In addition, networks keep the right on the series in the secondary markets, and attempt to increase the aggressive investment on new series on the base of the rights. However, such a risky investment can be the potential burden and risk for the networks in the future. This paper shows the importance of the reasonable risk sharing in the television drama industry to the Korean TV drama industry that has experienced the conflict between networks and independent production companies.