• 한국세라믹학회지
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• 제26권5호
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• pp.719-727
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• 1989

By using commercial zirconia powder CeO2-ZrO2 ceramics containing 8~16mol% CeO2 was made by heat treatment at 1350~155$0^{\circ}C$ for 1~10hr. The minimum amount of CeO2 for obtaining complete tetragonal phase was 12mol%, and in the tetragonal phase region fracture toughness of Ce-TZP was decreased with increasing CeO2 content and the maximum value was obtained when 12mol% CeO2 was added. The bending strength goes through maximum at 14mol% CeO2. Fracture mode of Ce-TZP transformed from intergranular to transgranular fracture with increasing CeO2 content, so the morphology of fracture surface of 16mol% Ce-TZP was wholly transgranular and this tendency was independent on grain size. The crystal structure of the 12mol% Ce-TZP was monoclinic with fringes along the grain boundaries which are lying in the particular plane from the TEM observation. The chemical composition of the sintered body was homogeneous as a whole and some amorphism or air pocket was observed at the triple junction.

• 천문학회보
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• 제38권2호
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• pp.32-32
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• 2013

The Korean VLBI Network (KVN) as a world-first multi-frequency VLBI system is operated at four bands of 22, 43, 86, and 129 GHz simultaneously. The performances of both single dish and VLBI network were already confirmed through single dish researches and VLBI evaluation test observations. The VLBI common use of the KVN at 22/43 GHz bands has been started from this autumn. The combined network of KVN and Japanese VERA (KaVA) will start the common use from the first half of next year. Here we present several observational results in the fields of star forming regions, late-type stars, and active galactic nuclei using the KVN and KaVA. The fringes of 44 GHz $CH_3OH$ (Class I) masers were detected from 26 sources for the first time using the KVN and imaging observations are under performing. Simultaneous observations of SiO and $H_2O$ masers toward about 1000 evolved stars showed the different maser properties between SiO and $H_2O$ masers according to the evolutionary stages of AGB and post-AGB stars. The catalog of correlated flux densities were established from a 43 GHz (Q-band) survey of 637 extragalactic sources. At 22 GHz (K-band), flux density measurement and fringe survey for new sources were performed toward a large number of sources. In addition, the large program of KVN and/or KaVA under planning is introduced.

• 대한기계학회논문집A
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• 제23권6호
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• pp.988-1000
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• 1999

An experimental study is presented for the effect of number of terms of a pewee series type stress function on stress analysis around a hole in tensile loaded plate. The hybrid method coupling photoelastsic data inputs and complex variable formulations involving conformal mappings and analytical continuity is used to calculate tangential stress on the boundary of the hole in uniaxially loaded, finite width tensile plate. In order to measure isochromatic data accurately, actual photoelastic fringe patterns are two times multiplied and sharpened by digital image processing. For qualitative comparison, actual fringes are compared with calculated ones. For quantitative comparison, percentage errors and standard deviations with respect to percentage errors are caculated for all measured points by changing the number of terms of stress function. The experimental results indicate that stress concentration factors analyzed by the hybrid method are accurate within three percent compared with ones obtained by theoretical and finite element analysis.

• 대한기계학회논문집
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• 제7권1호
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• pp.1-10
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• 1983

The photoelastic determination of S.I.F. in Fracture mechanics has been regarded as one of the most effective and practical experimental methods in which stresses are read directly, except a few shortcomings involved in the process of experiment; the difficulties of making a sharp crack tip similar to the practical one and nearly impossibilities of carving an arbitrarily shaped crack on the test plate, etc. To eliminate flaws mentioned above, recently, Kitagawa and Watanabe of Tokyo Univ.developed a new method named"Teflon Insert Method". which has improved experimental accuracy to a considerable extent byt remaining still room for further improvement, that is, the elimination of bonding boundary scars which render photoelastic fringes obscure. In this paper, a newly exploited"Teflon Molding Method" was attempted for the completion of teflon-epoxy experimental method. The experimental results obtained by this method are compared with existent theoretical and experimental values to evaluate its accuracy. As result, 1-6% of margin of errors were appeared in a series of photoelastic experiments which defied any other conventional method in terms of experimental accuracy.perimental accuracy.

• 패션비즈니스
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• 제14권3호
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• pp.1-19
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• 2010

The Assyrians usually wore two types - the tunic and the shawl. These two types were worn alone, or in combination and changes were introduced by varying the proportions of the tunic or shawl. The tunic appeared to be of the sleeves are short and reaching to the ankles or shortened to knee length according to the rank. Assyrian shawl pattern can be divided into five distinct styless. Many of the styles were suitable for costumes to wear in religious plays and pageants. Fringed shawls were the trademark of forma1 Assyrian costume. The usual badge of rank was a long fringed shawl. Intermediate rank wore shawl with short fringes and lower grade wore no shawl at all. The military costume was comparative uniformity : conical helmets was regarded as Scythic in character, short, fringed tunics, wide belts or helmet, round caps and long tunics covered in metal scales, belted at the waist. Assyrian woman costume was the long tunic with fringed hem and a long fringed shawl or was a plaid tunic and wide belt over it. They wore gold crown and horned Cap and tiara, ugal (head-dress) and the most ordinary earrings were the drop and the cross shape and necklace was made of the coloured stones and bracelets ended with heads of animal was regarded as Scythy style or adorned with a rosette at the centre.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.547-550
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• 2005

Gauge blocks are the most widely used material measure in length field in industry. The gauge block interferometer, which is the gauge block measuring system, comprises Twyman-Green type interferometer optics and light sources having precisely known wavelengths. This paper describes the work done for advancing the measurement system and automating the measurement process. The advancing of the system was done mainly by exchanging the spectral lamp with the frequency stabilized lasers, and the automation of measurement was achieved by modifying the hardware and developing the automatic measuring software. As the results of this work, the contrast of interferometric fringes of gauge blocks longer than 100 mm s enhanced about 20 times, and the measurement time has reduced down to 50% by automation.

• Journal of Photoscience
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• 제10권2호
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• pp.203-208
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• 2003

Two coupled molecules were successfully synthesized by condensation of amine-donor-substituted barbituric acid derivativies as nonlinear optical chromophores. A flexible spacer of the alkyl chain with different lengths of carbon chains (5 and 6 carbons) was introduced between two chromophores, which prevented crystallization and aggregation of molecules. Two coupled molecules (B-Cn-B, n=5, 6) had glass-transition temperatures on a second heating around 81 and 76$^{\circ}C$ without melting points, respectively. To explore the linear optical properties, thin-films were prepared and examined by a photometry method using Nd:YVO$_4$ CW laser. Also, microscopic and macroscopic nonlinear optical properties were measured by Hyper-Rayleigh Scattering (HRS) and the Maker Fringes method using Nd:YAG ps pulse laser, respectively. In spite of the moderate hyperpolarizabilities of coupled molecules, the second order NLO coefficient (d$\_$33/) was larger than the conventional Disperse Red 1 doped PMMA polymeric system.

• 한국의상디자인학회지
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• 제6권2호
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• pp.15-20
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• 2004

These days are referred to as 'the times of textile fashion,' owing to the emphasis on textile design in the fashion industry. Accordingly, apparel companies have increased their interests in developing new types of textiles to overcome the limits of style and silhouette. Now the ultra-fashion of textile, a new way of process and design development, is given much more attention. A Moire interference pattern has a longer wavy circle of interference, an effect of intensity interference, than one made by piling more than one reflecting plate or transmitting plate. Till now, Moire interference patterns have been used to confirm scientific theory and to measure the structure of a body or a subject in areas such as physics and medical science. Work has also been done on the Moire interference effects on TV screens said to cause dizziness and eye strain. This study focuses on the new types of textiles by creating the appearance of the Moire phenomena. Contrary to the present usual stationary patterns of textiles, it is a varying pattern according to the different gratings, different angles, piling gratings, and the movements of the human bodies. In the preceding study, we observed Moire fringes formed by overlapping two different or same kinds of gratings such as parallel line gratings, square gratings, conic gratings and semicircular gratings and tried to find a promising possibility of new textiles through the method of clothes design simulation.

• 대한기계학회논문집
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• 제9권6호
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• pp.788-794
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• 1985

본 논문에서는 유동산란입자들을 1개에서 35개까지 불규칙 상태로 배열한 13 가지의 모델을 만들어 probe volume 속으로 횡단시키므로 나타나는 신호를 분석하여 수밀도와 가시도에 대한 실험적 관계를 파악하고 이를 이론식과 비교검토하고자 했다. 또한 두 입자의 간격을 좁혀가면서 실험하므로 간섭무늬에 대한 두 입자의 입상차가 합성신호특성에 중요 파라미터임을 확인했다.

• 한국광학회지
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• 제12권3호
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• pp.230-234
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• 2001

반전대칭이 없는 광굴절결정에 있어 위상접합이 만족되지 않은 상태에서 발생된 제2고조파의 세기가 외부전기장에 의존한다는 사실을 이용하여 광굴적결정의 광굴절율 변형현상에 관한 중요상수를 측정할 수 있는 방법을 개발하였다. 마커무늬의 전기장의존도에 관한 근사식을 구하였고 이를 이용하여 제2고조파의 세기변화로부터 공간전하장의 크기를 측정할 수있었다. 실험적으로 congruent $LiNbO_3$에 빛을 두가지 다른 세기로 비추어 유도되는 공간저하장의 시간의존성을 조사하였고 측정결과를 근사식과 비교분석하여 $LiNbO_3$의 광기전력상수, 암전도상수 및 광전도상수를 결정할 수 있었다.