• Title/Summary/Keyword: Asymmetric Surface

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Optimization of Ultrathin Backlight Unit by Using a Tapered Light Guide Film Studied by Optical Simulation

  • Joo, Byung-Yun;Ko, Jae-Hyeon
    • Current Optics and Photonics
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    • v.1 no.2
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    • pp.101-106
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    • 2017
  • Optical structures of a tapered ultra-thin light guide film (LGF) were optimized by optical simulation for increasing coupling efficiency between light sources and the LGF. A serration pattern on the entrance side surface could provide a comparable coupling efficiency to that of the conventional LGF where a linear, asymmetric prism array was formed on the taper surface. Several micro-patterns were applied to the top and/or bottom surface of the LGF for achieving better luminance property, and it was found that an optimized micro-pyramid pattern exhibited the highest average luminance together with satisfactory luminance uniformity.

Surface magnetic properties of annealed $Co_{66}Fe_4B_{15}Si_{15}$ amorphous ribbons

  • L. Jin;Y. W. Rheem;Lee, B. S.;Kim, C. G.;Kim, C. O.
    • Proceedings of the Korean Magnestics Society Conference
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    • 2002.12a
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    • pp.208-209
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    • 2002
  • Recently an asymmetric giant magnetoimpedance (GMI) profile has been observed in Co-based amorphous ribbons annealed at the weak field [1-4]. This phenomenon has attracted a large interest due to its practical application to sensitive magnetic sensors. It is known [5.6] that in magnetic materials, the magnetoimpedance is caused by the effect of the magnetic field on the transverse magnetic permeability of a near-surface layer. In consequence of it, the value of the magnetoimpedance depends strongly on near-surface magnetic properties of the sample. (omitted)

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Control of surface defects on plasma-MIG hybrid welds in cryogenic aluminum alloys

  • Lee, Hee-Keun;Chun, Kwang-San;Park, Sang-Hyeon;Kang, Chung-Yun
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.7 no.4
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    • pp.770-783
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    • 2015
  • Lately, high production rate welding processes for Al alloys, which are used as LNG FPSO cargo containment system material, have been developed to overcome the limit of installation and high rework rates. In particular, plasma-metal inert gas (MIG) hybrid (PMH) welding can be used to obtain a higher deposition rate and lower porosity, while facilitating a cleaning effect by preheating and post heating the wire and the base metal. However, an asymmetric undercut and a black-colored deposit are created on the surface of PMH weld in Al alloys. For controlling the surface defect formation, the wire feeding speed and nozzle diameter in the PMH weld was investigated through arc phenomena with high-speed imaging and metallurgical analysis.

MERGING AND FRAGMENTATION IN THE SOLAR ACTIVE REGION 10930 CAUSED BY AN EMERGING MAGNETIC FLUX TUBE WITH ASYMMETRIC FIELD-LINE TWIST DISTRIBUTION ALONG ITS AXIS

  • Magara, Tetsuya
    • Journal of The Korean Astronomical Society
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    • v.52 no.4
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    • pp.89-97
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    • 2019
  • We demonstrate the subsurface origin of the observed evolution of the solar active region 10930 (AR10930) associated with merging and breakup of magnetic polarity regions at the solar surface. We performed a magnetohydrodynamic simulation of an emerging magnetic flux tube whose field-line twist is asymmetrically distributed along its axis, which is a key to merging and fragmentation in this active region. While emerging into the surface, the flux tube is subjected to partial splitting of its weakly twisted portion, forming separate polarity regions at the solar surface. As emergence proceeds, these separate polarity regions start to merge and then break up, while in the corona sigmoidal structures form and a solar eruption occurs. We discuss what physical processes could be involved in the characteristic evolution of an active region magnetic field that leads to the formation of a sunspot surrounded by satellite polarity regions.

Important Parameters Related With Fault for Site Investigation of HLW Geological Disposal

  • Jin, Kwangmin;Kihm, You Hong;Seo, Dong-Ik;Kim, Young-Seog
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.19 no.4
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    • pp.533-546
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    • 2021
  • Large earthquakes with (MW > ~ 6) result in ground shaking, surface ruptures, and permanent deformation with displacement. The earthquakes would damage important facilities and infrastructure such as large industrial establishments, nuclear power plants, and waste disposal sites. In particular, earthquake ruptures associated with large earthquakes can affect geological and engineered barriers such as deep geological repositories that are used for storing hazardous radioactive wastes. Earthquake-driven faults and surface ruptures exhibit various fault zone structural characteristics such as direction of earthquake propagation and rupture and asymmetric displacement patterns. Therefore, estimating the respect distances and hazardous areas has been challenging. We propose that considering multiple parameters, such as fault types, distribution, scale, activity, linkage patterns, damage zones, and respect distances, enable accurate identification of the sites for deep geological repositories and important facilities. This information would enable earthquake hazard assessment and lower earthquake-resulted hazards in potential earthquake-prone areas.

Surface Sediment and Suspended Material in Deukryang Bay (득량만의 퇴적물 및 부유물 특성)

  • 공영세;이병걸
    • 한국해양학회지
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    • v.29 no.3
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    • pp.269-277
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    • 1994
  • Process of resuspension and accumulation well explaines the characteristics of surface sediment size distribution and suspended material in Deukryang Bay. Most of the surface sediments of the bay show asymmetric unimodal size distribution, which is found also in sediments from western part of the inner shelf mud area between Keomundo and Yokchido islands. Investigation of the size curves indicates that surface sediment in Deukryang Bay is a deposit of suspended coastal sediment transported east along southern coast of Korea. The distribution pattern of coarse sit fraction content in the surface sediment is very similar to that of computed current velocity (Lee, 1994), suggesting that fine sediment on the bed may reassumed and accumulate repeatedly due to shallow depth and strong tidal current in Deukryang Bay. The process of repeated resuspension and accumulate repeatedly due to shallow depth and strong tidal current in Deukryang Bay. The process of repeated resuspension and accumulation seems to be responsible not only to the asymmetric size distribution of the surface sediment, but also to the amount of suspended material in the bay. The difference of suspended material concentration between surface and near bottom water in summer is two times as large as that the in winter. This seems to derive from the fact that stratification of water mass prevails in summer, while total water mass is vertically mixed in winter. It was found that the most important factors to decide distribution of suspended material in Deukryang Bay are the physical properties of water mass such as current velocity and stratification, and water depth, in part with the supply of suspended sediment by rivers.

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SURFACE BRIGHTNESS DISTRIBUTION ON NGC 7755

  • Chun, Mun-Suk;Sohn, Seong-Min
    • Journal of Astronomy and Space Sciences
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    • v.9 no.1
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    • pp.1-10
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    • 1992
  • Isophote map and luminosity profile of the barred spiral galaxy NGC 7755 are obtained from PDS scanning of PAL 0-471 plate. From the isophote map, NGC 7755 can be classified SBbc(r) with asymmetric bar ring. We get several physical parameters $({M_T}^\circ,U(R)_{CB},U(R)_{CD},D/B,C_{jj},M/L)$ of NGC 7755 from the analysis of the luminosity distribution.

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SOME REMARKS ON THURSTON METRIC AND HYPERBOLIC METRIC

  • Sun, Zongliang
    • Bulletin of the Korean Mathematical Society
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    • v.53 no.2
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    • pp.399-410
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    • 2016
  • In this paper, we study the relations between the Thurston metric and the hyperbolic metric on a closed surface of genus $g{\geq}2$. We show a rigidity result which says if there is an inequality between the marked length spectra of these two metrics, then they are isotopic. We obtain some inequalities on length comparisons between these metrics. Besides, we show certain distance distortions under conformal graftings, with respect to the $Teichm{\ddot{u}}ller$ metric, the length spectrum metric and Thurston's asymmetric metrics.

An Analog Experimental Model of the Formation Mechanism of Sedimentary Basins (퇴적분지형성 메커니즘에 관한 아날로그 모델 실험)

  • Kim, Woo-Seok;Jung, Jahe
    • The Journal of Engineering Geology
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    • v.28 no.3
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    • pp.397-409
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    • 2018
  • Izumi sedimentary basin (ISB), west of Shikoku, Japan, is widely distributed across the western side of the Sakuragi Bend of the Japan Median Tectonic Line (MTL). It is not obvious how the ISB formed, but this feature is similar to an asymmetric pull-apart basin. The stratigraphic succession and tuff layers show that ages tend to decrease toward the Sakuragi Bend. We investigate whether the ISB is an asymmetric pull-apart basin using analogue model experiments with running sand. A pull-apart basin of length 60 cm and width 20 cm is formed, and secondary normal faults appear on the surrounding surface. A cross-section parallel to the direction of displacement shows that the stratigraphic succession of the pull-apart basin becomes younger toward the releasing bend. A listric normal fault, which has the opposite dip to the master fault, is observed in a cross-section perpendicular to the direction of displacement. These results are consistent with the observed properties of the ISB west of Shikoku, thereby supporting the possibility that the ISB is an asymmetric pull-apart basin.