• Korean Journal of Materials Research
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• v.23 no.2
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• pp.135-142
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• 2013

The Ti-6Al-4V extra low interstitial (ELI) alloy has been widely used as an orthopedic implant material because of its excellent mechanical properties and biocompatibility. However, it still has many problems, including a high elastic modulus and toxicity of the Al and V elements. Therefore, non-toxic biomaterials with a low elastic modulus need to be developed. A high energy mechanical milling (HEMM) process is introduced to improve the effect of sintering. Rapid sintering of spark plasma sintering (SPS) under pressure was used to make an ultra fine grain of Ti-25 wt.%Nb-7 wt.%Zr-10 wt.%Mo-(10 wt.%CPP) composites with bio-attractive elements for increasing strength. These composites were fabricated by SPS at $1000^{\circ}C$ at 60 MPa using HEMM powders. During the sintering process, $CaTiO_3$, TixOy, and CaO were formed because of the reaction between Ti and CPP. The effects of CPP content on the physical and mechanical properties of the sintered Ti-Nb-Zr-Mo-CPP composites were investigated. The biocompatibility and corrosion resistance of the Ti-Nb-Zr-Mo alloys were improved by the addition of CPP.

• Applied Science and Convergence Technology
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• v.27 no.5
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• pp.95-99
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• 2018

We discuss the structural and optical characteristics of GaN nanowires (NWs) grown on Si(111) substrates by a plasma-assisted molecular-beam epitaxy. The GaN NWs with high crystal quality were formed by adopting a new growth approach, so called Ga pre-deposition (GaPD) method. In the GaPD, only Ga was supplied without nitrogen flux on a SiN/Si surface, resulting in the formation of Ga droplets. The Ga droplets were used as initial nucleation sites for the growth of GaN NWs. The GaN NWs with the average heights of 60.10 to 214.62 nm obtained by increasing growth time. The hexagonal-shaped top surfaces and facets were observed from the field-emission electron microscope images of GaN NWs, indicating that the NWs have the wurtzite (WZ) crystal structure. Strong peaks of GaN (0002) corresponding to WZ structures were also observed from double crystal x-ray diffraction rocking curves of the NW samples. At room temperature, free-exciton emissions were observed from GaN NWs with narrow linewidth broadenings, indicating to the formation of high-quality NWs.

• 한국초전도학회:학술대회논문집
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• v.12
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• pp.71-71
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• 2002

• Journal of the Korea Institute of Military Science and Technology
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• v.27 no.2
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• pp.265-276
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• 2024

The future battlefield operation concept does not focus on advanced and complete weapon systems, but requires a new battlefield operation concept that can effectively demonstrate offensive power by combining a large number of low-cost, miniaturized weapons. Recently, research on the autonomous application of major technologies that make up the mission control system is actively underway. However, since the mission control system is still dependent on the operator's operating ability when operating multiple robots, there are limitations to simply applying the automation technology of the existing mission control system. Therefore, we understand how changes in operator capabilities affect multi-robot operation and propose an adaptive mission control architecture design method that supports multi-robot integrated operation by adjusting the level of autonomy of the mission control system according to changes in operator capability.

• JSTS:Journal of Semiconductor Technology and Science
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• v.6 no.2
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• pp.61-67
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• 2006

We fabricate local damascene FinFET cell array in sub-60nm feature sized DRAM. The local damascene structure can remove passing-gate-effects in FinFET cell array. p+ boron in-situ doped polysilicon is chosen for the gate material, and we obtain a uniform distribution of threshold voltages at around 0.7V. Sub-threshold swing of 75mV/d and extrapolated off-state leakage current of 0.03fA are obtained, which are much suppressed values against those of recessed channel array transistors. We also obtain a few times higher on-state current. Based on the improved on- and off-state current characteristics, we expect that the FinFET cell array could be a new mainstream structure in sub-60nm DRAM devices, satisfying high density, low power, and high-speed device requirements.

• Proceedings of the Korean Magnestics Society Conference
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• 2005.12a
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• pp.216-216
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• 2005

• Nuclear Engineering and Technology
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• v.38 no.2
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• pp.119-128
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• 2006

We start to develop a predictable technology for thermal-hydraulic performance of the RMWR core using an advanced numerical simulation technology. As a part of this technology development, we are developing the advanced interface tracking method to improve the conservation of volume of fluid. The present paper describes a part of the development of the twophase flow simulation code TPFIT with the advanced interface tracking method. The numerical results applied to large-scale water-vapor two-phase flow in tight lattice rod bundles are shown and compared with experimental results. In the results of numerical simulation, a tendency of the predicted void fraction distribution in horizontal plane agreed with the measured values obtained by the advanced neutron radiography technique including the bridge formation of the liquid at the position of adjacent fuel rods where an interval is the narrowest.

• Electronics and Telecommunications Trends
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• v.39 no.3
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• pp.1-12
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• 2024

As the demand for high-performance semiconductors, such as chips for artificial intelligence and high-bandwidth memory devices, increases along with the limitations of ultrafine processing technology in the semiconductor in-line process, advanced packaging becomes an increasingly important breakthrough technology for further improving semiconductor performance. Major countries, including Korea, the United States, Taiwan, and China, and large companies are strengthening their technological industry capabilities through the development of advanced packaging technology and policy support. Nevertheless, Korea has a lower level of development of related technologies by approximately 66% compared with the most advanced countries. Therefore, we aim to discover the needs for an advanced packaging research and development (R&D) policy through written expert interviews and importance satisfaction analysis. As a result, various implications for R&D policy directions are suggested to strengthen the technological capabilities and R&D ecosystem of the Korean advanced packaging technology.

• Proceedings of the Korean Vacuum Society Conference
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• 2008.08a
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• pp.291-291
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• 2008

• Journal of Information Display
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• v.8 no.1
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• pp.22-25
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• 2007

Stereoscopic/autostereoscopic systems have been developed to express 3D images, but have not been successfully use in practise. In order to apply 3D display to promising applications such as advertisements and games, we developed a 42" 2D/3D switchable display. It has characteristics that do not require special glasses for 3D images, uses multi-view technology for improving 3D viewing characteristics, and has a 2D/3D switching function to express dynamic 3D contents as well as conventional 2D contents.