• 제목/요약/키워드: Translucent

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Translucent Cryptography의 취약점 개선 (The Improvement of Translucent Cryptography)

  • 김종희;이필중
    • 한국통신학회논문지
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    • 제27권12C호
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    • pp.1276-1281
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    • 2002
  • 키 복구 시스템의 대안으로 Bellare와 Rivest가 translucent cryptography의 개념을 소개하였다. Translucent cryptography란 사용자간의 암호 통신을 제3자가 확률 p(0$\leq$p$\leq$1)로 복구할 수 있는 시스템이다. 이 시스템에서는 사용자의 비공개키를 사전에 위탁할 필요가 없으며, p의 값을 조정함으로써 사용자와 복구 기관 사이의 균형을 조정할 수 있다. 예를 들어, p의 값을 0.4로 한다면 복구 기관은 사용자간의 암호 메시지 100개 중 40개를 복구할 수 있게 된다. 본 논문에서는 translucent cryptography에서 사용자가 손쉽게 복구 기관을 속여 복구 기관이 p의 확률만큼 복호화할 수 없는 문제점을 지적하고, 이에 대한 개선책을 제안한다.

FDM ABSi의 후가공을 통한 반투명 RP 재료의 개발 (Development of Translucent RP Material by Post-processing of FDM ABSi)

  • 정우벽;진영성;이홍경;안성훈
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.1193-1198
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    • 2003
  • Translucent plastics are commonly used in packaging of mechanical and/or electrical components. Although Rapid Prototyping(RP) provides prototypes of various materials, translucent RP parts are not readily available from most RP processes. ABSi is one of the ABS materials available for Stratasys' FDM process, and the material has potential to be translucent. In this paper, two post-processing techniques were applied in order to increase optical transmissivity of the parts made of FDM's ABSi. First, elevated temperature condition was applied resulting in increased transmissivity while dimensional shrinkage was observed. Second, resin infiltration and surface sanding provided upto 16% transmissivity without shrinkage. These post-processes can be selectively applied to increase transmissivity of ABSi parts. Thus, translucent FDM part can be fabricated from regular FDM process followed by the post-processes developed in this study.

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후가공을 통한 반투명 RP 재료의 개발: FDM의 예 (Development of Translucent RP Material by Post-processing: Case Study of FDM)

  • 정우벽;이선영;안성훈
    • 대한기계학회논문집A
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    • 제27권9호
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    • pp.1524-1530
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    • 2003
  • Translucent plastics are commonly used in packaging of mechanical and/or electrical components. Although Rapid Prototyping(RP) provides prototypes of various materials, translucent RP parts are not readily available from most RP processes. ABSi is one of the ABS materials available for Stratasys' FDM process, and the material had potential to be translucent. In this paper, two post-processing techniques were applied in order to increase optical transmissivity of the parts made of FDM's ABSi. First, elevated temperature condition was applied resulting in increased transmissivity while dimensional shrinkage was observed. Second, resin infiltration and surface sanding provided up tp 16 % transmissivity without shrinkage. These post-processes can be selectively applied to increase transmissivity of ABSi parts. Thus, translucent FDM part can be fabricated from regular FDM process followed by the post-processes developed in this study.

Translucent Microemulsion의 제조 공정과 안정성 (Manufacturing Process of Translucent Microemulsion and Its Stability)

  • 배덕환;신재섭
    • 한국응용과학기술학회지
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    • 제17권3호
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    • pp.167-173
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    • 2000
  • The process variables for the manufacture of translucent microemulsion prepared with 2-octyl dodecanol, 12-hydroxy stearic acid cholesteryl , POE(40)HCO and 1,3-butandiol were examined initially (primary emulsion) and following aging for three months. The techniques empolyed in this study were particle size, turbidity, interfacial tension and microfluidizer. Particle size analysis and turbidity measurement to evaluate the emulsion stability were used. It was concluded that the process of the emulsification was an important indicator of the stability of the translucent microemulsion. From the particle size and and turbidity measurement of translucent microemulsion, adding the surfactant to the oil phase before the emulsification was found to be the most important factor for the stability of emulsions. We found that interfacial tension of the adding the surfactant to the oil phase is lower than that of the adding the surfactant to aqueous phase. In spite of hydrophilic surfactant, adding the surfactant to aqueous phase produced inferior emulsion to that to oil phase.

고등어(Scomber japonicus) 이석의 초륜 형성 및 연령 사정 (First Annulus Formation and Age Determination for Otoliths of Chub Mackerel Scomber japonicus)

  • 강수경;정경미;차형기
    • 한국수산과학회지
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    • 제48권5호
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    • pp.760-767
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    • 2015
  • First annulus formation and age determination of otoliths were examined for chub mackerel Scomber japonicus collected in Korean waters over the one year from January to December in 2009. Translucent zone was regarded as an annual mark. Age interpretation criteria was based on the data of the number of translucent zone, capture date, and edge type of the otolith, assuming the nominal birthday to be 1 January. Monthly changes in mean marginal index indicated that translucent zone was formed once a year, mainly in June. The otolith of 0-ring group was detected comparing the progression by month of the smaller fish length, appearing to be a single first opaque zone. The average distance from the core to the first translucent zone was ~1.77 mm, provided as supplementary information to increase ageing accuracy. The ageing criteria for chub mackerel was made to determine correct year-class with the purpose of effective stock assessment. This method using nominal birthdate and edge type analysis could estimate age of fish closer to the true age than purely counting the number of translucent zone on a whole otolith.

반투명 콘크리트의 제조기법 개발과 무기혼화재 혼입에 따른 역학적 특성 (Development of Fabrication Method for Translucent Concrete and the Material Characteristics Associated with the Use of Mineral Admixture)

  • 김상철
    • 한국건설순환자원학회논문집
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    • 제6권3호
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    • pp.69-78
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    • 2011
  • 최근 콘크리트제품에 대한 고급화, 고품질화 및 고강도화 등의 추구로 변화함에 따라 구조물의 미적효과와 전시 목적의 제품 고급화를 위해 반투명 콘크리트를 제작하였다. 본 연구에서는 반투명 콘크리트의 제조기법 개발을 통해 다양한 형상의 블록 제조방식을 소개하고, 또한 반투명 콘크리트의 물성 평가와 더불어 경제적인 반투명 콘크리트 제조를 위해 무기혼화재인 고로슬래그와 플라이애시의 활용 및 유리알갱이의 적용방안에 대해 검토하였다. 물성평가 결과, 반투명 콘크리트 블록의 28일 압축강도는 32.2MPa이고 탄성계수와 푸아송비는 일반 콘크리트 블록에 비해 증가되어 압축을 받는 부재일 경우 일반 콘크리트 구조물과 같이 구조적 용도로도 사용이 가능하다는 것을 알 수 있었다. 시멘트 대체재로써 플라이애시 적용하였을 때 동일 양의 광섬유를 포함한 반투명 콘크리트 블록의 28일 강도의 85~96%의 값을 보였으며, 고로슬래그 미분말을 적용하였을 때에는 82~96%의 값을 보였다. 또한, 광섬유대체재로서 유리알갱이를 적용한 결과, 빛의 투과효과가 전혀 나타나지 않아 대체효과가 전혀 없는 것으로 나타났다.

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Fashion Design using Art Flower Technique - Based on Transparency Image -

  • Lee Youn-Hee
    • The International Journal of Costume Culture
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    • 제8권1호
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    • pp.32-42
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    • 2005
  • This paper aims to propose fashion designs based on the application of art flower technique to translucent clothing material. For study method, firstly I looked into art flower applications occurred in modern trend since 2000 as well as theoretical research on art flower and transparency expressed as artificial beauty. Second, I attempt to express transparency in a variety of unique ways by using the art flower technique in producing clothes. Third, I utilized transparent flower with translucent clothing material and tried to suggest fashion design attempting mixture of new materials. As a result, firstly transparent image and material are well fitted in with modern trend and especially it was very suitable for expressing feminine beauty. Second, transparency was the element to suggest creative formative world in fashion design in regard to flower's beauty, various shapes and colors and to provide infinite materials as design motive. Third, the combination of knit clothing and plastic art flower displayed a new form of material combination. Especially as translucent material is fitted with trend such as function, lightness and variableness in modern times of the $21^{st}$ century, it presents beautiful combination with transparent flower. Fourth, Silk flower technique is variously used in art flower techniques. Various possibility ranges are presented such as flower was recreated with artificial image by silk flower technique to be newly expressed and various materials like aesthete film can be also expressed with silk flower technique.

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Powder Injection Molding of Translucent Alumina using Supercritical Fluid Debinding

  • Kim, Hyung Soo;Byun, Jong Min;Suk, Myung Jin;Kim, Young Do
    • 한국분말재료학회지
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    • 제21권6호
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    • pp.407-414
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    • 2014
  • The powder injection molding process having advantages in manufacturing three-dimensional precision parts essentially requires a debinding process before sintering to remove the binders used for preparing feedstock. In this study, powder injection molding of translucent alumina was performed, and carbon dioxide ($CO_2$) is used as a supercritical fluid that makes it possible to remove a large amount of binder, which is paraffin wax. The relationship between the optical property of translucent alumina and the debinding condition (temperature and pressure) of supercritical $CO_2$ was investigated. As temperature and pressure increased, extraction rate of the binder showed rising tendency and average grain size after sintering process was relatively fine. On the other hand, optical transmittance was reduced. As a result, the debinding condition at $50^{\circ}C$ and 20 MPa that represents the lowest extraction rate, $8.19{\times}10^{-3}m^2/sec$, corresponds to the largest grain size of $14.7{\mu}m$ and the highest optical transmittance of 45.2%.

Degree of conversion of resin composite cured by light through a translucent fiber posts

  • Urapepon, Somchai
    • The Journal of Advanced Prosthodontics
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    • 제6권3호
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    • pp.194-199
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    • 2014
  • PURPOSE. This study evaluated the depth of cure of resin composite cured by light through a translucent fiber post. MATERIALS AND METHODS. The opaque plastic tubes in various lengths of 2, 4, 6, 8, 10, 12, 14 mm. were filled with resin composite in which two different translucent fiber posts were inserted into the center and photo-polymerized for 40 seconds. The degree of conversion of the cured composite at bottom surface were examined using Fourier transform infrared attenuated total reflection spectrometer (FTIR/ATR) at 0.1, 0.5 and 1.0 mm apart from the post surface. RESULTS. The degree of conversion of the 0.1 mm, 0.5 mm, 1.0 mm apart from the post surface was highest at the 2 mm level and continuously decreased when the distance from the light source was increased and drastically decreased when the depth from the top of the post was greater than 4-6 mm. For each level, the highest degree of conversion was at 0.1 mm from the post surface and decreased continuously when the distance apart from the post surface was increased. CONCLUSION. The quantity of light transmission depends on the type of post and the light transmission capability of the post, especially after 4-6 mm depth and the area further apart from the post surface, are insufficient for clinical light activation of resin composite.

분말사출성형 시 분말 혼합체의 유동성 시뮬레이션을 통한 투광성 알루미나 소결체의 특성 연구 (A study on the Powder Injection Molding of Translucent Alumina via Flowability Simulation of Powder/Binder Mixture)

  • 김형수;변종민;김세훈;김영도
    • 한국분말재료학회지
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    • 제21권3호
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    • pp.215-221
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    • 2014
  • Translucent alumina is a potential candidate for high temperature application as a replacement of the glass or polymer. Recently, due to the increasing demand of high power light emitting diode (LED), there is a growing interest in the translucent alumina. Since the translucent property is very sensitive to the internal defect, such as voids inside or abnormal grain growth of sintered alumina, it is important to fabricate the defect-free product through the fabrication process. Powder injection molding (PIM) has been commonly applied for the fabrication of complex shaped products. Among the many parameters of PIM, the flowability of powder/binder mixture becomes more significant especially for the shape of the cavity with thin thickness. Two different positions of the gate were applied during PIM using the disc type of die. The binder was removed by solvent extraction method and the brown compact was sintered at $1750^{\circ}C$ for 3 hours in a vacuum. The flowability was also simulated using moldflow (MPI 6.0) with two different types of gate. The effect of the flowability of powder/binder mixture on the microstructure of the sintered specimen was studied with the analysis of the simulation result.