• Journal of the Korean Society of Industry Convergence
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• v.6 no.3
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• pp.201-205
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• 2003

The effects of adsorption and desorption of alkali-metals on Si(111) surface were investigated by using AES and RHEED-system. The adsorption system is a fundamental interest because of its unique electronic properties such as measurement of work function change, adatom-core level shift. It was found that the growth node of K on Si(111) surface was layer by layer growth and the saturation coverage was 2.0ML at room temperature. Superstructure changes on Si(111) surface according to the alkali-metal thickness and substrate temperatures were accurately defined. By applying the isothermal desorption method, the desorption energies of Li/Si(111) and K/Si(111) surfaces was measured. On Li/Si(111) and K/Si(111) surfaces, the desorption energies were 3.07 eV, 2.19 eV respectively.

• Journal of the Korean Society of Industry Convergence
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• v.20 no.2
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• pp.149-155
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• 2017

Mechanical properties of carbon coated $SiC_f/SiC$ composites have been investigated, in conjunction with a detailed analysis of microstructure. Especially, the fracture behavior of $SiC_f/SiC$ composites by the induction of carbon coating layers has been examined. The matrix region of $SiC_f/SiC$ composites with ultra-fine SiC powders were consolidated by a liquid phase sintering (LPS) process, using a sintering additive of $Al_2O_3-Y_2O_3$ powder compound. In this composite, plain and satin- woven Tyranno SA fabrics were also utilized as a reinforcing material. A carbon interfacial layer was coated around satin-woven SiC fabrics. The characterization of LPS-$SiC_f/SiC$ composites was investigated by means of SEM and three point bending test.

• The Journal of Society for e-Business Studies
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• v.2 no.1
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• pp.131-151
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• 1997

The CALS/EC is the world-wide accepted concept and its application domain is being expanded continuously throughout the private and public sectors. One of the essential points for realization of CALS/EC is to promote the domestic system integration(SI) industry. This paper describes the present status of the domestic SI companies and the clues to solve their facing problems. In order to evaluate the status of the current SI technology, the MBNQA(Malcom Baldridge National Quality Award) is adopted. The surveyed results show that the average levels of 14 SI companies over 7 evaluation criteria turn out to be 30% through 40% point. The major projects' activities of the SI companies on the information systems over the areas of trade, science and technology, industrial manpower, health and welfare, national security, etc are explained. Also, the competitive power of the SI companies is also discussed. As a target sample, the Korea Telecom(KT) CALS model project is described in terms of its Progresses and Problems. Furthermore, the strategic plans and detailed research items are proposed to resolve on-going issues.

• Proceedings of the KSPS conference
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• 2005.11a
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• pp.13-16
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• 2005

As language learning that utilizes speech and information processing technology is getting popular. Speech Information Technology & Promotion Center(SiTEC) has created and is distributing speech corpora for STiLL in order to support basic research and development of products. We will introduce the corpus for Korean and those for English which we have created and are distributing.

• Journal of the Korean Society of Industry Convergence
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• v.7 no.4
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• pp.349-354
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• 2004

The growth mode of the Si layers which were grown on Si(111) by using Ag as surfactant were investigated by intensity oscillations of the RHEED specular spot at the different temperatures. we found that the introduction of Ag as the surfactant alters the growth mode from a three-dimensional clustering mechanism to a two-dimensional layer-by-layer growth. In the growth of Si layers on Si(111) with a surfactant Ag, At $450^{\circ}C$, RHEED intensity oscillation was very stable and periodic from early stage of deposition to 32 ML. RHEED patterns during homoepitaxial growth at $450^{\circ}C$ was changed from $7{\times}7$ structure into ${\sqrt{3}}{\times}{\sqrt{3}}$ structures. Since the ${\sqrt{3}}{\times}{\sqrt{3}}$ structure include no stacking fault, the stacking fault layer seems to be reconstructed into normal stacking one at transition from the $7{\times}7$ structure to a ${\sqrt{3}}{\times}{\sqrt{3}}$ one. We also found that the number of the intensity oscillation of the specular spot for Si growth with a surfactant Ag was more than for Si growth without a surfactant. This result may be explained that the activation energy decrease for the surface diffusion of Si atoms due to segregation of the surfactant toward the growing surface.

• Resources Recycling
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• v.31 no.1
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• pp.3-11
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• 2022

Silicon is the most abundant metal element in the Earth's crust. Metallurgical-grade silicon (MG-Si) is an important metal that has wide industrial applications, such as a deoxidizer in the steelmaking industry, alloying elements in the aluminum industry, the preparation of organosilanes, and the production of electronic-grade silicon, which is used in the electronics industry as well as solar cells. MG-Si is produced industrially by the reduction smelting of silicon dioxide with carbon in the form of coal, coke, or wood chips in electric arc furnaces. MG-Si is purified by chemical treatments, such as the Siemens process. Most single-crystal silicon is produced using the Czochralski method. These smelting and refining methods will be helpful for the development of new recycling processes using secondary silicon resources.

• Resources Recycling
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• v.19 no.5
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• pp.44-49
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• 2010

SiC powders have been recovered from silicon-containing waste slurry by carbothermal reduction method with carbon black. Large amount of silicon-containing waste slurry is generated from Solar Cell industry. In an environmental and economic point of view, retrieve of the valuable natural resource from the silicon waste is important. In this study, SiC powder recovered by the reaction ball-milled silicon powder from waste and carbon black at $1350^{\circ}C$ for 3h under vacuum condition. Physical properties of samples have been characterized using SEM, XRD, Particle size analyzer and FT-IR spectroscopy.

• Resources Recycling
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• v.32 no.1
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• pp.60-66
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• 2023

As supply chain management becomes a key factor in the sustainable growth of the industry, securing minerals at the national or corporate level is becoming important. Depending on the industrial structure, the economic status of each minerals is different and the supply risk is different In this study, to examine the economic status of minerals, an index that can quantify the Industrial Economic Importance by minerals was developed and calculated by reflecting the demand structure and cost weight of each industry. As a result, Li, Al, Cu, Si, Co, Ni, etc. were evaluated as having high industrial importance in Korea. In addition, by industry, Al, Cu, Zn, and Pb for primary metal manufacturing, general machinery, assembly metals,Sn, Ba, Ti, Si and Ga for precision equipment, Si and Ga for semiconductors, and Li, Ni, Co, Si, etc. for electronic components had high industrial importance. Such as Europe and the United States, in order to select Critical-minerals, Korea will need to analyze the economic impact on the domestic industry as well as the risks of supply chain by minerals.

• Nuclear industry
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• v.26 no.7 s.281
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• pp.38-39
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• 2006

• Nuclear industry
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• v.27 no.2 s.288
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• pp.2-4
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• 2007