• Title/Summary/Keyword: Edge characteristics

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Pixel value prediction algorithm using three directional edge characteristics and similarity between neighboring pixels

  • Jung, Soo-Mok
    • International Journal of Internet, Broadcasting and Communication
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    • v.10 no.1
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    • pp.61-64
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    • 2018
  • In this paper, a pixel value prediction algorithm using edge components in three directions is proposed. There are various directional edges and similarity between adjacent pixels in natural images. After detecting the edge components in the x-axis direction, the y-axis direction, and the diagonal axis direction, the pixel value is predicted by applying the detected edge components and similarity between neighboring pixels. In particular, the predicted pixel value is calculated according to the intensity of the edge component in the diagonal axis direction. Experimental results show that the proposed algorithm can effectively predict pixel values. The proposed algorithm can be used for applications such as reversible data hiding, reversible watermarking to increase the number of embedded data.

METHOD FOR REAL-TIME EDGE EXTRACTION USING HARDWARE OF LATERAL INHIVITION TYPE OF SPATIAL FILTER

  • Serikawa, Seiichi;Morita, Kazuhiro;Shimomura, Teruo
    • 제어로봇시스템학회:학술대회논문집
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    • 1995.10a
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    • pp.236-239
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    • 1995
  • It is useful to simulate the human visual function for the purpose of image-processing. In this study, the hardware of the spatial filter with the sensitivity of lateral inhibition is realized by the combination of optical parts with electronic circuits. The diffused film with the characteristics of Gaussian type is prepared as a spatial filter. An object's image is convoluted with the spatial filter. From the difference of the convoluted images, the zero-cross position is detected at video rate. The edge of object is extracted in real-time by the use of this equipment. The resolution of edge changes with the value of the standard deviation of diffused film. In addition, it is possible to extract a directional edge selectively when the spatial filter with directional selectivity is used instead of Gaussian type of spatial filter.

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A Study on the Flow Characteristics around a Coanda Control Surface

  • Hong, Seok-Jin;Lee, Seung-Hee
    • Journal of Ship and Ocean Technology
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    • v.8 no.2
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    • pp.13-19
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    • 2004
  • Jet flows applied tangential to a foil surface near the leading and/or trailing edges increase the lift of the foil by delaying the separation also known as the Coanda effects. Many experimental and numerical studies have proven the effectiveness of Coanda effects on circulation control and the effects have been found to be useful in practical application in many aerodynamics fields. Most of the previous works have studied the effects of the jet blowing near the trailing edges and investigated the influence of jet momentum on lift. A few experimental studies, however, focused on the separation bubble that develops near the leading edge and applied jet flow the edge to remove the bubble but only to find decrease in lift. In the present paper, a Coanda foil of 20% thickness ellipse with modified rounded leading and trailing edges was investigated, and the flow around the foil was numerically studied. The blowing around the leading edge only decreased the lift, as the experiments showed, but the suction considerably increased the lift.

Stress Analysis of Double T-Welded Joints Considering External Forces (외력을 고려한 양면 T-용접이음부의 음력해석)

  • 김성환;방한서;방희선;송관형
    • Journal of Welding and Joining
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    • v.19 no.2
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    • pp.215-220
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    • 2001
  • In the T-joint welding, the complete penetration joint which is obtained by groove welding with edge preparation is generally required thor the safety and reliability of structures but this way have the some defects such as increase of working time, consumed welding electrode quantity and large welding deformation. If there is no probrem, in the strength, T-joint welding without edge preparation will be profitably understood in the economical and welding deformation side. In this paper, we performed the finite element analysis to understand the characteristics of welding residual stresses on two models, complete penetration joint have the edge preparation and incomplete penetration joint without edge preparation, respectively. Especially, we observed the relation between welding residual stress distributed on the notch of gap in the root and external force in the incomplete penetration joint without edge preparation.

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Gas now Analysis Around Strip Edge During Gas Wiping for CGL (용융아연도금설비의 gas wiping시 강판표면의 기체 유동해석)

  • Hwang, W. G.;Sung, W. S.;Kim, H.;Chung, J. H.;Park, R. B.
    • Journal of the Korean institute of surface engineering
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    • v.34 no.2
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    • pp.115-124
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    • 2001
  • Gas wiping process of continuously hot-dip galvanized coating on steel strip has noise and coating problems. To improve the qualify of product, characteristics of air flow on the steel surface must be investigated. In this paper, fluid dynamic model of the gas flow is setup and solved numerically using STAR-CD. The effects of edge baffle, distance between steel plane edge and baffle, inlet pressure, and gap between air knife and strip steel surface are investigated, and it is concluded that edge baffle can reduce over-coating and edge built-up.

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Numerical Study on the Unsteady Flow Characteristics under the Effect of Blade Leading Edge Modification in the 1st Stage of Axial Turbine (1단 터빈 내 앞전 변형의 영향 하에 공력 특성에 대한 비정상 수치해석적 연구)

  • Kim, Dae-Hyun;Min, Jae-Hong;Chung, Jin-Taek
    • The KSFM Journal of Fluid Machinery
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    • v.12 no.1
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    • pp.22-27
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    • 2009
  • The important problems that arise in the design and performance of the axial flow turbine are the prediction and control of secondary flows. Some progresses have been made on understanding flow conditions that occur when the inlet endwall boundary layer separates at the point in the endwall and rolls up into the horseshoe vortex. And the flows though an axial turbine tend to be extremely complex due to its inherent unsteady and viscous phenomena. The passing wakes generated from the trailing edge of the stator make an interaction with the rotor. Unsteady flow should be considered rotor/stator interactions. The main purpose of this research is control of secondary flow and improvement efficiency in turbine by leading edge modification in unsteady state. When the wake from the stator ran into the modified leading edge of the rotor, the leading edge generated the weak pressure fluctuation by complex passage flows. In conclusion, leading edge modification(bulb2) results in the reduced total pressure loss in the flow field.

Canard-Leading Edge Flap Scheduling for the Maneuverability Enhancement of a Fighter Class Aircraft (전투기급 항공기 기동성 증대를 위한 카나드-앞전플랩 스케줄링)

  • Chung, In-Jae;Kim, Sang-Jin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.35 no.2
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    • pp.165-170
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    • 2007
  • During the conceptual design phase of a wing-body-canard type fighter class aircraft, as a method of maneuverability enhancement for an aircraft, effects of canard-leading edge flap scheduling have been studied. In this study, corrected supersonic panel method has been used to predict the drag polar characteristics due to canard-leading edge flap deflections in the high speed regime. Utilizing the predicted drag polar curves, the canard-leading edge flap scheduling laws have been established. These scheduling laws are the relation of canard-leading edge flap deflections and the flight conditions to maximize the lift-drag ratio. Based on the results obtained from the canard-leading edge flap scheduling, the present method has shown to be useful to enhance the maneuverability of wing-body-canard type fighter class aircraft.

Study of MOSFET Subthreshold Hump Characteristics by Phosphorous Auto-doping

  • Lee, Jun-Gi;Kim, Hyo-Jung;Kim, Gwang-Su;Choe, Byeong-Deok
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.319-319
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    • 2012
  • 현재 폭넓게 이용되고 있는 STI (Shallow Trench Isolation) 공정에서 active edge 부분에 발생하는 기생 transistor의 subthreshold hump 특성을 제어하는 연구가 활발히 이루어지고 있다. 일반적으로 STI 공정을 이용하는 MOSFET에서 active edge 부분의 얇게 형성된 gate oxide, sharp한 active edge 형성, STI gap-fill 공정 중에 생기는 channel dopant out-diffusion은 subthreshold hump 특성의 주된 요인이다. 이와 같은 문제점을 해결하기 위해 active edge rounding process와 channel dopant compensation의 implantation을 이용하여 subthresold hump 특성 개선을 연구하였다. 본 연구는 STI 공정에 필요한 wafer와 phosphorus를 함유한 wafer를 한 chamber 안에서 auto-doping하는 방법을 이용하여 subthresold hump 특성을 구현하였다. phosphorus를 함유한 wafer에서 빠져나온 phosphorus가 STI 공정중인 wafer로 침투하여, active edge 부분의 channel dopant인 boron 농도를 상대적으로 낮춰 active edge 부분의 가 감소하고 leakage current를 증가시킨다. transistor의 channel length, gate width이고, wafer#No가 클수록 phosphorous를 함유한 wafer까지의 거리는 가까워진다. wafer #01은 hump 특성이 없고, wafer#20은 에서 심한 subthreshold hump 특성을 보였다. channel length 고정, gate width를 ~으로 가변하여 width에 따른 영향을 실험하였다. active 부분에 대한 SCM image로 확인된 phosphorus에 의한 active edge 부분의 boron 농도 감소와 gate width vs curve에서 확인된 phosphorus에 의한 감소가 narrow width로 갈수록 커짐을 확인하였다.

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A Study on Edge Detection Algorithm using Grey Level Converting Function (그레이 레벨 변환 함수를 이용한 에지 검출 알고리즘에 관한 연구)

  • Lee, Chang-Young;Hwang, Yeong-Yeun;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.10a
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    • pp.921-923
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    • 2015
  • Edge in the image includes the size, direction and location of objects. The existing detection methods for detecting this edge is a method using Sobel, Prewitt, Roberts and Laplacian, etc. These existing methods use a fixed weighted mask in order to detect the edge and have somewhat insufficient edge detection characteristics. Therefore in this paper, an algorithm that detects the edge by applying the grey level converting function according to the pixel distribution of local mask was proposed.

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New Cultivar 'Blue Edge' of Leaf Variegated Hosta minor (좀비비추의 잎변이 품종 'Blue Edge' 육성)

  • Kim, Hyun-Jin;Lee, Jong Suk
    • Korean Journal of Plant Resources
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    • v.25 no.5
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    • pp.652-655
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    • 2012
  • 'Blue Edge' (Hosta minor) was induced by ethyle methane sulfonate (EMS) to obtain mutants. Among induced leaf variegated hosta plants, some with deep-green color pattern on the edge of the leaves was selected. They were cultivated via vegetative propagation. Assessment of botanical characteristics was conducted for three years since 2003. The major characteristic of these cultivars is that they maintain their deep-green color on the edge of the leaves all year round. These cultivars are useful as materials for pot plant or as ground cover plant.