• Title/Summary/Keyword: Source depth

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Precise Stereo Matching Technique Based on White Auxiliary Stripe (백색 보조 띠 기반의 정밀 스테레오 정합 기법)

  • Kang, Han-Sol;Ko, Yun-Ho
    • Journal of Korea Multimedia Society
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    • v.22 no.12
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    • pp.1356-1367
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    • 2019
  • This paper proposes a novel active stereo matching technique using white auxiliary stripe pattern. The conventional active stereo matching techniques that uses two cameras and an active source such as projector can accurately estimate disparity information even in the areas with low texture compared to the passive ones. However, it is difficult that the conventional active stereo matching techniques using color code patterns acquire these patterns robustly if the object is composed of various colors or is exposed to complex lighting condition. To overcome this problem, the proposed method uses an additional white auxiliary stripe pattern to get and localize the color code patterns robustly. This paper proposes a process based on adaptive thresholding and thinning to obtain the auxiliary pattern accurately. Experimental results show that the proposed method more precisely measures the stepped sample whose depth is known in advance than the conventional method.

Scatter Dose in soft tissue using the partial attenuation filter for 6 MV X-ray of linear accelerator (6 MV 광자선조사면내 투과성필터에 의한 조직선량)

  • 최태진;김옥배
    • Progress in Medical Physics
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    • v.4 no.1
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    • pp.55-71
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    • 1993
  • Measured and calculated the TMR and SMR factors from percent depth dose underpartial attenuators which cover the whole part of the radiation beam with variousfilter thickness from 0 to 50 mm. This study was performed for x-ray beams generated with a 6 MV linear acceleratorat source to surface distance of 100cm in a water phantom for Lipowitz metal. TMR(0,d,t) was derived from non-linear polynomial regression with field sizedifferencies and a given filter thickness. In this experiments, the TMR(0,10,50) of 50mm of filter thickness was showed13.6 % higher than that of open field and SMR(5,10,50) was 38.5% smaller than thatof open field in same depth.

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Laboratory, Field and Deep Seawater Culture of Eucheuma serra-a High Lectin Yielding Red Alga

  • Dinabandhu Sahoo;Masao Ohno;Masanori Hiraoka
    • ALGAE
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    • v.17 no.2
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    • pp.127-133
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    • 2002
  • The red seaweed Eucheuma serra is a high yielding source of lectins. The plants were collected from a depth of 5-6 meters and cultured in the laboratory, field and deep seawater. A Daily Growht Rate (DGR) of 3.5% was observed at 18℃ with a low light of 30μmol photon $ m^{-2} · s^{_1}$ in the laboratory. When the plants were cultured in the field at different depths during winter onths of December and January, best growth was observed at 1 m depth and a DGR of 2.14±0.04% was recorded. The plants grown in the tank with a continuous supply of deep seawater showed a DGR of 8.2% The results indicate that E. serra can be cultivated in large scale both in deep seawater in the tank and in the field for the extraction of lectins at a commercial scale.

Peak force control in the milling process (엔드밀 공정에서 최대 절삭력 제어)

  • 김홍겸;이건복
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2001.04a
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    • pp.188-191
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    • 2001
  • Generally, main factors of tool damage are cutting speed, feed rate and depth of cut. The increase of those factors can cause tool breakage or worsen product quality such as machining accuracy deterioration. Those three factors are concerned with cutting force. Cutting force reaches at its maximum value when cutter blade cuts away the object directly, and it is the time when tool damages are at high probability. In this study, we detect the maximum cutting force affecting tool damage and control the maximum cutting force based on the measured peak force.

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Flow-Guider Applied to Controlling Current in a Bay (도류제에 의한 항만내 조류제어 연구)

  • 양찬규;홍기용
    • Journal of Ocean Engineering and Technology
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    • v.11 no.4
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    • pp.141-151
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    • 1997
  • This paper deals with a numerical study of flow-guider applied to controlling current in a bay. Two dimensional numerical model for tidal currents based on the depth averaged equation is developed and standard k-.epsilon. model is adopted to determine the turbulence diffusion. Equations are described in a generalized coordinate system to be implemented by non-staggered grid system and discretized by using finite volume method. Unsteady flow is simulated by fully implicit scheme. Hybrid scheme and central differencing are used to compute the convective terms and source terms, respectively. The tidal current in a rectangular bay is simulated and it gives satisfactory results. The realistic and distinct models of a large structure placed in bay are also exemplified with or without flow-guiders. The simulation results show that the flow-guider gives the residual tidal current in the bay by the different flux with respect to the direction of tidal current.

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Characterization and Design Consideration of 80-nm Self-Aligned N-/P-Channel I-MOS Devices

  • Choi, Woo-Young;Lee, Jong-Duk;Park, Byung-Gook
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.6 no.1
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    • pp.43-51
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    • 2006
  • 80-nm self-aligned n-and p-channel I-MOS devices were demonstrated by using a novel fabrication method featuring double sidewall spacer, elevated drain structure and RTA process. The fabricated devices showed a normal transistor operation with extremely small subthreshold swing less than 12.2 mV/dec at room temperature. The n- and p-channel I-MOS devices had an ON/OFF current of 394.1/0.3 ${\mu}A$ and 355.4/8.9 ${\mu}A$ per ${\mu}m$, respectively. We also investigated some critical issues in device design such as the junction depth of the source extension region and the substrate doping concentration.

Temperature variation in steel beams subjected to thermal loads

  • Abid, Sallal R.
    • Steel and Composite Structures
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    • v.34 no.6
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    • pp.819-835
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    • 2020
  • The effects of atmospheric thermal loads on the response of structural elements that are exposed to open environments have been recognized by research works and design specifications. The main source of atmospheric heat is solar radiation, which dominates the variation of the temperature of air, earth surface and all exposed objects. The temperature distribution along the depth of steel members may differ with the geometry configuration, which means that the different-configuration steel members may suffer different thermally induced strains and stresses. In this research, an experimental steel beam was instrumented with many thermocouples in addition to other sensors. Surface temperatures, air temperature, solar radiation and wind speed measurements were recorded continuously for 21 summer days. Based on a finite element thermal analysis, which was verified using the experimental records, several parametric studies were directed to investigate the effect of the geometrical parameters of AISC standard steel sections on their thermal response. The results showed that the overall size of the beam, its depth and the thickness of its elements are of significant effect on vertical temperature distributions and temperature differences.

Dust Scattering in Turbulent Media: Correlation between the Scattered Light and Dust Column Density

  • Seon, Kwang-Il;Witt, Adolf N.
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.1
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    • pp.59.2-59.2
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    • 2014
  • Radiative transfer models in a spherical, turbulent interstellar medium (ISM), in which the photon source is situated at the center, are calculated to investigate the correlation between the scattered light and the dust column density. The medium is modeled using fractional Brownian motion structures that are appropriate for turbulent ISM. The correlation plot between the scattered light and optical depth shows substantial scatter and deviation from simple proportionality. It was also found that the overall density contrast is smoothed out in scattered light. In other words, there is an enhancement of the dust-scattered flux in low-density regions, while the scattered flux is suppressed in high-density regions. The correlation becomes less significant as the scattering becomes closer to being isotropic and the medium becomes more turbulent. Therefore, the scattered light observed in near-infrared wavelengths would show much weaker correlation than the observations in optical and ultraviolet wavelengths. We also find that the correlation plot between scattered lights at two different wavelengths shows a tighter correlation than that of the scattered light versus the optical depth.

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A Study of Chemical Mechanical Polishing on Shallow Trench Isolation to Reduce Defect (CMP 연마를 통한 STI에서 결함 감소)

  • 백명기;김상용;김창일;장의구
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.501-504
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    • 1999
  • In the shallow trench isolation(STI) chemical mechanical polishing(CMP) process, the key issues are the optimized thickness control within- wafer-non-uniformity, and the possible defects such as nitride residue and pad oxide damage. These defects after STI CMP process were discussed to accomplish its optimum process condition. To understand its optimum process condition, overall STI related processes including reverse moat etch, trench etch, STI filling and STI CMP were discussed. It is represented that the nitride residue can be occurred in the condition of high post CMP thickness and low trench depth. In addition there are remaining oxide on the moat surface after reverse moat etch. It means that reverse moat etching process can be the main source of nitride residue. Pad oxide damage can be caused by over-polishing and high trench depth.

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A Study on the Improvement of Visual Acuity on an Edgelit Panel (Edge 조명 광고판의 시각효과 개선에 대한 연구)

  • Shin, Kyung-Ho;Song, Sang-Bin;Lee, Jeong-Bin;Yeo, In-Seon
    • Proceedings of the KIEE Conference
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    • 2003.07c
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    • pp.1735-1737
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    • 2003
  • To find the best intagliated shape on edgelit signboard, it was prepared wilt variations of illumination by changing the depth and angle of an engraved letter, the thickness of acrylic panel and wavelength of light source in this paper. As the result of analyzing optical design program, shallower depth and larger than critical angle on a visible side of panel, a favorable illumination characteristics was found. Also considering those factors, it was able to select the model which showed effectively engraved letter.

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