• 대한기계학회논문집A
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• 제32권11호
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• pp.1016-1021
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• 2008

The development of the first wall whose major function is to withstand high neutron and heat fluxes is a critical path to fusion power. The materials database and the fabrication technology are being developed for design, construction and safety operation of the fusion reactor. The first wall was designed to consist of the plasma facing armor, the heat sink layer and the supporting plates. and Porous materials are of significant interest due to their wide applications in catalysis, separation, lightweight structural materials. In this study, the characteristics of the sintering process of SiC ceramic, $SiC_f$/SiC composite and porous $C_f$/SiC composite have been introduced order to study of the fusion blanket materials and heat-exchange pannel.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 추계학술대회 논문집
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• pp.34-37
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• 2005

While all-aluminum front end carriers have been frequently used by major foreign auto-makers, the carriers domestically produced are typically hybrid types. It is understood that higher fuel efficiency due to weight reduction can be achieved by using aluminum carriers because of aluminum's light weight. Moreover, aluminum is expected to posess high corrosion resistance and recyling rate. As a first step to enhance feasibility of domestic production of all-aluminum carriers, several carriers made by advanced auto makers are examined and compared. Besides basic characteristics such as appearance and weight, physical properties including composition, strength and elongation are carefully analyzed to obtain critical design and process factors.

• 태양에너지
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• 제18권3호
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• pp.137-146
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• 1998

In this paper, the current status of manufacturing technologies for GaAs/Si solar cell were revived and provied new MOCVD. In the manufacturing process of GaAs/Si solar cells and an experiment to get the high efficiency GaAs solar cells, we must investigate the optimum growth conditions to get high quality GaAs films on Si substrates by MOCVD. The GaAs on Si substrates has been recognized as a lightweight alternative to pure substrate for space applicaton. Because its density is less the half of GaAs or Ge.So GaAs/Si has twofold weight advantage to GaAs monolithic cell. The theoretical conversion efficiecy limit of tandem GaAs/Si solar cell is 32% under AM 0 and $25^{\circ}C$ condition. It was concluded that the development of cost effective MOCVD technologies shoud be ahead GaAs solar cells for achived move high efficiency III-V solar cells involving tandem structure.

• Current Optics and Photonics
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• 제1권2호
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• pp.150-156
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• 2017

A diffraction limited optical system for head mounted displays (HMDs) was designed. This optical system consists of four modules, including 1:5 mm and 5:30 mm beam expanders, polarization grating-polarization conversion system (PG-PCS) and refractive/diffractive projection optical module. The PG-PCS module transforms the unpolarized Gaussian beam to a linearly polarized beam and it simultaneously homogenizes the spatial intensity profile. The optical projector module has a $30^{\circ}$ field of view, a 22 mm eye relief, and a 10 mm exit pupil diameter with a compact structure. Common acrylic materials were utilized in the optical design process; therefore, the final optical system was lightweight. The whole optical system is suitable for a 0.7 inch liquid crystal on silicon microdisplay (LCOS) with HDTV resolution ($1920{\times}1080$) and $8.0{\mu}m$ pixel pitch.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.461-466
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• 2004

The hybrid composite carbody structures were considered as the carbody system of Korean Tilting Train eXpress(TTX) to achieve the lightweight design. The TTX carbodies are composed of the carbody shell made of the sandwich composite structure and the undeframe made of the metal structure. The sandwich structures were used to minimize the weight of carbody, and the metal underframe was used to modify the design easily and to keep the strength of underframe by the installation of the electrical equipments. The sandwich carbody structures will be cured in an autoclave. In this paper, the manufacturing processes of the TTX carbody structures were introduced briefly.

• 대한치과의사협회지
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• 제56권6호
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• pp.339-347
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• 2018

Conventional mouthguard fabrication process which consists of elastomeric impression taking and followed gypsum model making is changing into intraoral scanning and dental model printing with 3D printer. In addition, new 3D printing materials for mouthgurad, 3D Computer-Aided Design(CAD) software for dental appliance, evaluation of a virtual dentoalveolar model for testing virtually 3D designed mouthguard, and lightweight sensor technology will lead dental professionals to the new era of Sports Dentistry, including information technology integrated custom mouthguard fabrication and creating value with analytic data acquired from sensors in mouthguard.

• 한국생산제조학회지
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• 제25권2호
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• pp.138-142
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• 2016

In this study, a strength analysis was performed to assess die-cast aluminum alloy brake pedals as an improved alternative to wrought alloys. Aluminum brake pedal shapes are considered to be suitable for the die-casting process. The strength criterion of Volvo trucks was used as the criterion for the pedal strength. The results of this analysis showed that the frame thickness of the aluminum brake pedal must be increased from 12 mm to 18 mm to have a strength superior to that of a steel brake pedal. Additionally, the stress and weight of the aluminum brake pedal were found to be approximately 24% and 26% lower than those of the steel brake pedal, respectively. Mounting tests and strength assessments verified that the proposed die-cast aluminum alloy brake pedal demonstrated sufficient strength.

• 한국철도학회논문집
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• 제3권2호
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• pp.92-99
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• 2000

Composites are very useful material for light train carbody due to its high specific strength and lightweight characteristics. The composites, called 3-D board, are developed with a special stitching method. In this process, the glass fiber fabrics of skin material and foam core material are stitched together with glass fiber thread. The glass thread in Z-axis turns into FRP form. The conventional delamination problem can be solved with 3-D sandwich structure. In addition, with the lower density of foam, the weight of the panel and the operation expenses can be highly reduced. To evaluate the usefulness of the 3-D board, the double-deck light train carbody is studied. The stress analyses are carried out under various loads and boundary conditions with FEM Code, ANSYS. On comparing with the aluminum carbody, 3-D board carbody can be reduced by about 2 ton for the total weight of carbody.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2003년도 International Symposium
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• pp.165-172
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• 2003

Wafer-level packaging technology has become established with increase of demands for miniaturizing and realizing lightweight electronic devices evolution. This packaging technology enables the smallest footprint of packaged chip. Various structures and processes has been proposed and manufactured currently, and products taking advantages of wafer-level package come onto the market. The package enables mounting semiconductor chip on print circuit board as is a case with conventional die-level CSP's with BGA solder bumps. Bumping technology is also advancing in both lead-free solder alternative and wafer-level processing such as stencil printing using solder paste. It is known lead-free solder bump formation by stencil printing process tend to form voids in the re-flowed bump. From the result of FEM analysis, it has been found that the strain in solder joints with voids are not always larger than those of without voids. In this paper, characteristics of wafer-level package and effect of void in solder bump on its reliability will be discussed.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2010년도 춘계학술발표논문집 1부
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• pp.9-13
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• 2010

This paper proposes an object-oriented software development guidance and an evaluation index for the productivity related to Seam Framework. Heavyweight and lightweight architecture to resolve the problem with benefits to support the new architecture is a large size distributed object standardization architecture. This architecture, such as the Seam Framework, to provide all of the architecture is possible. The distributed object standardization architecture is most often used in business Seam Framework is well-known architecture. Therefore, this study is based on the Seam Framework large distributed object architecture, design and implementation of standardization software development productivity and the objective is to provide guidance.