• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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• pp.169-172
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• 2004

We fabricated MWNT-added glass fabric/epoxy composites. We observed the distribution of MWNTs in the composites using scanning electron microscopy and conformed that most of MWNTs exist in matrix rich region and interface between yams in warp and fill directions. We also investigated the change of permittivities with MWNT concentrations. Only $1wt\%$ MWNTs leads to high permittivity and electromagnetic waves are impossible to be transmitted to more than $3wt\%$ MWNT-added composites, which means the characteristics of these composites are comparable to those of metals or carbon fiber-reinforced composites.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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• pp.51-54
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• 2004

Testing methods for mechanical properties of the advanced composites were introduced. The mechanical properties, such as tensile properties, compressive properties, in-plane shear properties, flexural properties, and interlaminar shear properties, were evaluated along the warp and the fill directions. The CF3327 of the carbon fabric, the HG1581 of the glass fabric, and the HK285 of the aramid fabric were considered as reinforcements. Epoxy and phenolic resin were used as resin. The experimental results obtained in this study would be applicable in the design and structural analysis for the manufacture of the carbody of the tilting train.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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• pp.246-249
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• 2004

When MWK (Multiaxial Warp Knitted Fabric) composites are applied for the structures, the connections of each component using mechanical fastening is needed. The local contact between the bolted joint and the composite laminates may induce high stress concentration or breakdown in the laminates for the mechanical joints. There for, it is strongly required to study the characteristics of mechanically joints of MWK composite laminates. In this study, stress analysis near the hole boundary of MWK composite laminate is conducted with various geometric factors under different loadings. In the case of multi-pin loaded MWK composite laminates, the results show that the types of loadings and geometric factors of mechanical joints have a significant influence on the joint performances.

• 한국의류학회지
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• 제28권8호
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• pp.1057-1064
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• 2004

Silk, polyester, cotton, and wool fabrics were embroidered with varying stitch length of 3mm, 5mm, and 10mm to examine the difference in fabric shrinkage in terms of sewing direction, fabric thickness, cover factor, stitch length, and fiber type. Warp, filling, and bias direction of sewing resulted in no difference in fabric shrinkage. Within the samples with same stitch length, there was less fabric shrinkage in fabrics with higher fabric thickness or higher cover factor. There was larger shrinkage when sewn with longer stitch length. Comparing fabrics with different fiber types but similar fabric thickness, silk and polyester fabrics showed the smallest fabric shrinkage and wool fabrics showed the largest shrinkage. It is shown that similar fabric shrinkage between silk and polyester is due to the similarity in cover factor.

• 한국염색가공학회지
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• 제14권5호
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• pp.261-267
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• 2002

Cotton fabrics were immersed in aqueous solution of N-methylmorpholine N-oxide(NMMO) with various concentrations, padded by 300% of pick-up, concentrated at $90^\circ{C}$ for 30min under constant-length condition, washed, and dried, to examine a possibility of linen-like finishing by the solvent bonding between fibers. With increasing the concentration of NMMO, cross-sections of fibers changed to oval or polygonal shapes and not only the fibers but also the warp and weft were bonded each other, which produced linen-like effect on the fabrics in the aspects of appearance and mechanical properties such as the Increase of stiffness and shear properties. The thickness, moisture regain and dyeability were increased with the concentration of NMMO.

• 연구논문집
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• 통권22호
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• pp.75-83
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• 1992

The beating motion of a high speed shuttleless loom is driven by cams. Two cams become one system and their shaft laid across each other. Moreover, the shape of the cams is very complex and requires high precision for successful weft insertion and good interlacing with warp yarn. The iterative contact method is developed for use in design and analysis of the driving mechanism of a disk type cam with oscillating roller follower. The optimum design is performed by utilizing a CAD program, DISKCAM. The 8th order polynomial is selected to interpolate the desired shape trajectory of the cam, the optimal shape of the cams is defined based on the demension of the follower. The kinematic motion of the beating cam mechanism is investigated. The phase angle is determined to achive harmonious cam motions

• 한국정밀공학회지
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• 제15권7호
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• pp.85-90
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• 1998

The business of manufacturing is increasingly becoming time-compressing, precise and long-life oriented, owing to various needs from the consumers and harsh global competition. With the emergence of the layer laminate manufacturing method, it is possible to produce prototypes directly from 3D CAD and additive process, the production time and cost have shortened dramatically. However there are some problems like surface-step, dimensional deviation and warp. A newly developed powder casting is suitable for rapid-manufacturing metallic tools. Powder casting can serve as a promising rapid tooling method because of high density characteristics and low dimensional shrinkage below 0.1％ during sintering and infiltration. By this process, we have realized significant time savings bypassing the wait for prototype tooling and cost savings eliminating the expense of conventional prototype tooling process.

• 기계저널
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• 제35권1호
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• pp.46-52
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• 1995

지금에 이르기까지 직기개발을 위한 주안점은 새로운 위입시스템(water-jet, air-jet)의 개발과 지속적인 직기의 생산속도증가에 대한 각 위입요소들의 최적동작을 위한 기계요소의 개발에 주 어져 있었다. 반면에 위입동작과 직접 연관되지 않는 직기의 구성요소들은 증가하는 위입속도에 따라 각 기능의 안정성과 동작의 정확성에 대한 요구가 점차 증가되었으며, 특히 경사장력 및 이에 작용하는 기계요소들에 대한 기술적 요구수준은 과거의 북직기에서의 경우에 비교될 수 없을 정도의 한계적 상황을 만족시켜야 하게 되었다. 경사송출의 경우, 위사 1가닥이 공급될 때 마다 직물권취에대응하여 경사장력을 일정하게 유지하며, 경사의 일정 길이를 정확히 공급하여야 하기 때문에 고속 무북직기에서는 빠른 응답속도와 안정된 동작을 행할 수 있는 경사송출기구 및 장력제어시스템의 성능이 직기성능에 가장 큰 영향을 미치게 되었으며 지금까지 사용되어온 기계적 송출장치로는 한계적 기술요건을 만족시킬 수 없게 되었다. 이에 따라 근자에 이르러 경사장력제어형 장력송출장치의 응용이 크게 대두되고 있다. 이 글에서는 이러한 새로운 형태의 송출장치의 개발상황과 경사장력제어에서 해결되지 못한 문제점에 대하여 다루어 보고자 한다.

• 패션비즈니스
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• 제10권6호
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• pp.9-15
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• 2006

Colors of textile products or fashionable clothing play one of the most important roles. From the point of visual cues, the realism of an image is the result of a good interaction of local light scattering or transmittance model applied. A 3-dimensional CAD software was used to construct a solid plain fabric model. In order to simulate a union fabric with different warp and filling colors, rendering was performed on the fabric model. It was demonstrated that the iridescent effect, pearl effect, or superficial color change effect of the union fabric during wearer's movement could be explained using the fabric models at inclined fabric positions during viewer's observation.

• 대한의용생체공학회:의공학회지
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• 제21권5호
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• pp.519-526
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• 2000

볼륨 렌더링은 3D 의료영상 데이터를 가시화하는 중용한 기법 중 하나이다. 그러나 볼륨 렌더링을 실시간으로 이룰 때, 많은 계산량을 필요로하는 것이 볼률 렌더링을 사용하는데 걸림돌이 되고 있다. 이 논문에서는 Superscalar와 VLIM(Very Long Instruction Word)의 구조를 가지고 있어 동시에 8개의 명령어 수행이 가능한 TI사의 TMS320C6201 DSP를 이용하여 3D 초음파 영상의 쉬어-웝 볼륨 렌더링을 구현하였다. 쉬어-웝 방법을 DSP 상에서 최적으로 구현하기 위하여 ray map 방법, one-to-four ray casting, ？디 skipping 방법을 제안하였다. 제안한 방법들을 이용한 볼륨 렌더링과 적용하지 않은 기존의 알고리즘을 DSP에 구현하여 PSNR과 렌더링 시간의 비교·평가를 통해 만족할 만한 영상 화질에 빠른 렌더링 성능을 얻을 수 있음을 보여주었다.