• Title/Summary/Keyword: angle dependence

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Some Studies on Stress field in Dissimilar Materials

  • Katsuhiko Watanabe
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.631-635
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    • 1996
  • Stress singularities appear at the interface edge in dissimilar materials also under thermal loading. First, these singularities then an interface meets a free side surface with an arbitrary angle are studied for a two-dimensional problem. The singular properties under thermal loading are made clear and the concrete singular field are obtained. Secondly, the dependence of stress field on elastic constants in axisymmetric dissimilar materials are. discussed. That is, it is shown that three elastic constants mutually independent are necessary, in general, to characterize the stress field of axisymmetric dissimilar materials, although Dunders' parameters defined for two-dimensional dissimilar materials have been often applied correspondingly also to axisymmetric problems.

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전자가 도핑된 Sr0.9La0.1CuO2초전도체의 홀 효과

  • Kim, Hyun-Jung;W. N. Kang;Kim, Kijoon H. P.;Lee, Sung-Ik;S. Karimoto
    • Progress in Superconductivity
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    • v.4 no.1
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    • pp.32-36
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    • 2002
  • We have measured the Hall effect in infinite-layer Sr/sub 0.9/La/sub 0.1/CuO2 thin films grown by molecular beam epitaxy. We do not observe T2 dependence of the cotangent of Hall angle, which is commonly observed in other cuprate High-Tc superconductors. Therefore, this result cannot be interpreted within two different scattering mechanism based on charge-spin separation theory. The mixed-state Hall effect shows no sign anomaly, implying that tile hydrodynamic contribution of vortex core is negligibly small.

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Shear Layer and Wave Structure Over Partially Spanning Cavities

  • Das, Rajarshi;Kim, Heuy Dong;Kurian, Job
    • Journal of the Korean Society of Visualization
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    • v.11 no.2
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    • pp.46-54
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    • 2013
  • Study of the wave structure and shear layer in the vicinity of a wall mounted cavity is done by time averaged colour schlieren and time resolved instantaneous shadowgraph technique in an M=1.7 flowfield. Effect of change of cavity width on flow structure is investigated by using constant length to depth (L/D) ratio cavity models with varying length to width (L/W) ratio of 0.83 to 4. The time averaged shock wave structure was observed to change with change in cavity width. Dependence of the shock angle at the leading edge on the shear layer width is also evident from the images obtained. Unsteadiness in the flow field in terms of shear layer dynamics and quasi steady nature of shock waves was evident from the images obtained during instantaneous shadowgraph experiments. Apart from the leading and trailing edge shocks, several other waves and flow features were observed. These flow features and the associated physical phenomena are discussed in details and presented in the paper.

Sputtering of traget materials by the ion scattering monte carlo calculation (이온 산란 몬테칼로 계산에 의한 시료 물질의 스퍼터링)

  • 김영삼;이상석;김영권;최은하;조광섭
    • Journal of the Korean Vacuum Society
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    • v.8 no.1
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    • pp.55-62
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    • 1999
  • Monte Carlo ion scattering program is improved with the single scattering methods where the total cross section and the mean free path are calculated as a function of atomic density during ion scattering in matter. The relations among the parameters of incident ions and substrate materials are investigated to the sputtering phenomena. The sputtering yield has been analyzed with the dependence on the incident ion species and energy, incident angle, and surface binding energy. The energy distribution of sputtered particles is discussed.

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Rigorous coupled-wave analysis of antireflective surface-relief gratings

  • Han, Chang-Wook;Cho, Doo-Jin;Rhee, Bum-Ku
    • Journal of the Optical Society of Korea
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    • v.1 no.1
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    • pp.26-35
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    • 1997
  • Rigorous coupled-wave analysis (RCWA) with a simplified eigenvalue problem is used to investigate the an-tireflective property of one-dimensional surface-relief gratings such as binary gratings, triangular gratings and gratings with triangle-like surface profiles. The convergence of RCWA is investigated by varying the number of layers and the number of space-harmonics used in the computation. For unpolarized light normally incident on a medium of refractive index 1.64 from vaccum, a triangle-like grating shows the reflectivity of 1.6×104 in contrast to a minimum reflectivity of 3.8×103 for a binary grating. We also study the dependence of reflectivity on the wavelength, and on the angle of incidence for a groove shape and depth which result in minimum reflectivity.

Optimization of a Ventilation System for Indoor Environment Improvement in School Building (학교교실의 환경개선 환기시스템 최적화 기반 연구)

  • Suh, Seung-Jik;Hong, Sung-Hee;Park, Hyo-Soon;Park, Jong-Hoon;Jang, Yong-Sung
    • Proceedings of the SAREK Conference
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    • 2005.11a
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    • pp.229-234
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    • 2005
  • This study aims to build basic data for a optimization of a ventilation system for indoor environment improvement in school building. To this end, we conducted field tests and computation fluid dynamics simulations about a indoor environment in dependence on operation of a ceiling type inverter air conditioner and ventilation system. The results could be summarized as follows. (1) For the ventilation system of 350CMH, 500CMH and 850CMH, reduction of each CO2 concentration was measured 662ppm, 748ppm and 526ppm. (2) A optimal discharge angle of the ceiling type inverter air conditioner system was evaluated 45 degree in heating and cooling.

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Preparation and Characterization of Cellulose Esters Langmuir-Blodgett(LB) Films (셀룰로오스 에스터의 LB 막 제조 및 분석)

  • Kim, Dong Won;Park, Sang Rae
    • Journal of the Korean Chemical Society
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    • v.38 no.2
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    • pp.87-91
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    • 1994
  • The reparation and characterization of cellulose esters LB films with various alkyl chain lengths were studied. Monolayers of cellulose triesters with medium chain length such as trioctanoate(C-8), tridecanoate(C-10), and tridodecanoate(C-12), exhibited a characteristic phase transition from expanded to condensed states. The mechanism of phase transition was discussed on the basis of the temperature dependence of the surface pressurearea(πA) isotherms. By the horizontal dipping method, X-type multilayers of cellulose esters were prepared and characterized using the contact angle and XPS spectra.

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Performance of LOB-based Emitter Localization Using Linear LSE Algorithms (선형 LSE 알고리즘을 이용한 신호원 위치 추정 성능)

  • Lee, Joon-Ho;Kim, Min-Cheol;Cho, Seong-Woo;Kim, Sang-Won
    • Journal of the Korea Institute of Military Science and Technology
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    • v.13 no.1
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    • pp.36-40
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    • 2010
  • In this paper, the well-known LOB-based emitter localization using linear LSE algorithm is numerically implemented and the heuristic guidelines for the parameter values to achieve 1% RMS error are presented. In the simulation, we changed the total observation durations for LOB measurements, time interval between successive LOB measurements and sensor trajectories. The effects of the time interval of LOB measurements, the time duration of the LOB measurements and the angle of flight path arc on the performance are illustrated. The dependence of the performance on the various parameters is investigated and rule-of-thumbs for the parameter values corresponding to 1% RMS error are presented for each simulation condition.

The Measurement on Diffraction Efficiency in Polarization Holography using Amorphous Chalcogenide Thin Films (칼코게나이드 박막을 이용한 편광 홀로그래픽의 회절효율 측정)

  • 장선주;여철호;이현용;정홍배
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.87-90
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    • 1999
  • The dependence of diffraction efficiency as a funct~on of film thickness and incident angle has been investigated in amorphous chalcogenide thin films, which act as a polarization holographic materials. Especially a-(Se, S) based films exhibit a number of photoinduced phenomena not observed in other types of amorphous thin films. Holographic gratings in amorphous As-Ge-Se-S thin films have been formed using the mutual perpendicular polarized(linearly) He-Ne laser light. We could obtain the optimum condition to get high diffraction efficiency.

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Cell gap measurement method far single-polarizer reflective liquid crystal cells (분광기를 이용한 반사형 TN LCD의 셀갭 측정)

  • 이기동;박경호;이서헌;윤태훈;김재창
    • Korean Journal of Optics and Photonics
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    • v.12 no.6
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    • pp.468-471
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    • 2001
  • A novel method to measure the cell gap of a single-polarizer reflective twisted nematic liquid crystal (TN LC) cell by using a rotating polarizer technique is proposed. By rotating an LC cell, we can measure the cell gap of an LC cell as well as the wavelength dependence of retardation under the condition that the twist angle is known.

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