• Title/Summary/Keyword: homogeneous region

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Speckle noise elimination of ultrasonic images by using generalized noise model and adaptive weighted median filter (일반형 잡음모델과 적응성 가중 메디안 필터를 이용한 초음파 영상의 스펙클 잡음 제거)

  • 윤귀영;안영복
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.34S no.7
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    • pp.89-101
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    • 1997
  • A technical method of noise modeling and adaptive filtering reducing of speckle noise in ultrasonic medical images is presented. By adjusting the characteristics of the filer according to local statistics around each pixel of the image as moving windowing, it is possible to suppress noise sufficiently while preserve edge and other significant information required in diagnosis. Homogeneous factor(HF) from the noise models that enables the filter to recognize the local structures of the image is introduced, and an algorithm for determining the HF fitted to the diagnostic systems with various inner statistical properties is proposed. We show by the experimented that the performance of proposed method is superior to these of other filters and models in preserving small details and suppressing the noise at homogeneous region.

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The Analysis of Circumference Through-Wall Cracked Pipe Considering Weld Characteristic (용접부 강도불균질을 고려한 원주방향관통균열 배관의 파괴역학 해석법)

  • Park, Bo-Gyu;Oh, Chang-Kyun;Kim, Yun-Jae;Kim, Young-Jin;Kim, Jong-Sung;Jin, Tae-Eun
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.31-36
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    • 2004
  • Defective components of interest include not only homogeneous components, but also components with weldments where tensile properties vary across the weldment. Noting that the region near the weldment is the most vulnerable place for crack initiation and subsequent growth, defect assessment methods for homogeneous structure. Moreover, weldment width and crack location also affects the deformation and fracture behavior of the welded joints. These weld characteristics can evaluate using plastic limit load. So in this paper, evaluate plastic limit load both full circumference part-throughwall cracked pipes and circumference through-wall cracked pipes considering weld characteristics. And using evaluate results, proposed J-integral and crack opening displacement(COD) estimate method based on reference stress method.

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A New Face Detection Method by Hierarchical Color Histogram Analysis

  • Kwon, Ji-Woong;Park, Myoung-Soo;Kim, Mun-Hyuk;Park, Jin-Young
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.138.3-138
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    • 2001
  • Because face has non-rigid structure and is influenced by illumination, we need robust face detection algorithm with the variations of external environments (orientation of lighting and face, complex background, etc.). In this paper we develop a new face detection algorithm to achieve robustness. First we transform RGB color into other color space, in which we can reduce lighting effect much. Second, hierarchical image segmentation technique is used for dividing a image into homogeneous regions. This process uses not only color information, but also spatial information. One of them is used in segmentation by histogram analysis, the other is used in segmentation by grouping. And we can select face region among the homogeneous regions by using facial features.

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Disparity estimation using adaptive window in hierarchical framework (다중프레임 구조에서 적응적 윈도우를 이용한 변이추정)

  • Yoon, Sang-Un;Min, Dong-Bo;Sohn, Kwang-Hoon
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.433-434
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    • 2006
  • A new disparity estimation method in hierarchical frameworks is proposed. The two main ideas for improving accuracy are to obtain an object boundary map for distinction of homogeneous/object boundary region and to choose adaptive window size/shapes. Moreover, for the reduction of computational complexity, we change reference regions in hierarchical framework. The experimental results show that the proposed method can acquire good results which are robust to homogeneous and object boundary regions.

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SAR Pattern of Biological Objects Contacted with Coaxial Waveguide Antenna Using the FDTD Method (유한 차분법을 이용한 동축 도파관 안테나에 접촉된 생체의 SAR 패턴에 관한 연구)

  • Koo, Sung-Mo;Lee, Chang-Won;Won, Chul-Ho;Cho, Jin-Ho
    • Journal of Biomedical Engineering Research
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    • v.18 no.3
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    • pp.261-266
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    • 1997
  • Nonevasive multifrequency microwave radiometry using coaxial waveguide antenna has been investigated for a homogeneous and four layer human body model. The coupling between coaxial waveguide antenna and a biological object was analyzed by use of the finite-difference time-domain(FDTD) method to obtain the absorbed power patterns in the media. The object studied in this paper was a homogeneous and four-layered lossy medium. The specific absorption rates(SAR) distribution which was corresponding to the temperature distribution was calculated in each region by use of the steady-state response in FDTD method. The SAR pattern of 1.2GHz was compared with that of 1.8GHz.

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SAR Pattern of Biological Objects Contacted with Coaxial Waveguide Using the FDTD Method

  • Koo, Sung-Mo;Won, Chul-Ho;Lee, Chang-Won;Cho, Jin-Ho
    • Proceedings of the KOSOMBE Conference
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    • v.1996 no.11
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    • pp.185-188
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    • 1996
  • Noninvasive multifrequency microwave radiometry using coaxial waveguide antenna has been investigated for a homogeneous and four layer human body model. The coupling between coaxial waveguide antenna and a. biological object is analyzed by use of the FDTD method to obtain the absorbed power patterns in the media. The object studied in this paper is a homogeneous and four-layered lossy medium. The specific absorption rates(SAR) distribution is calculated in each region by use of the steady-state response in FDTD method.

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Multimode Configuration Doped with a Chiral Agent for Transflective Liquid Crystal Display with a Single Cell Gap

  • Yu, Chang-Jae;Kim, Jin-Yool;Kim, Dong-Woo;Lee, Sin-Doo
    • Journal of Information Display
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    • v.5 no.3
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    • pp.8-13
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    • 2004
  • We demonstrate a transflective liquid crystal display (LCD), doped with a chiral agent to produce a low helical twisting power, in a multimode configuration consisting of the homogeneous alignment and the hybrid alignment. The multimode transflective LCD with a single cell gap was fabricated using a single-step photoalignment technique with a self-masking process of an array of metal reflectors in the reflective region. In our configuration, the electro-optical disparity between the transmissive region and the reflective region was found to be significantly reduced by the low helical twisting power of the chiral dopant.

A Study on the Flow Patterns on the Myunggi-Noksan Region due to Reclamation (명지 . 녹산 해역 매립후의 해수 유동에 관한 연구)

  • 한건모;김기철;김재중
    • Journal of Ocean Engineering and Technology
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    • v.7 no.1
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    • pp.81-91
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    • 1993
  • Studies on the flow pattern due to reclamation in the Myunggi-Nocksan region are carried out based on field observations and numerical experiments. Serial time series measurement of current, temperature and salinity were conducted for 1 tidal period at intervals of 1 hour from surface to bottom on station located at 128.deg. 54' 44" E, 35.deg. 01' 04" N in April and June 1992. Surface current opposite to the subsurface current causes turbulent mixing to make homogeneous salinity pattern in vertical section. Reclamation has little effect on the wave pattern and flow patterns are also nearly similar except on the nearby region of reclamation where flow speed somewhat weakened.

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REGION-ORIENTED TRANSFORM CODING OF STILL IMAGES USING VORONOI DIAGRAMS AND SCHMIDT'S ORTHOGONALIZATION

  • Ichiro-Matsuda;Susumu-Itoh
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 1999.06a
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    • pp.69-76
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    • 1999
  • This paper proposes a new region-oriented coding scheme of still images. The scheme first segments an image into homogeneous regions by making use of Voronoi diagrams. Then luminance components in each Voronoi region are encoded using a transform coding technique which employs the Schmidt's orthogonalization method to produce orthonormal basis-functions for arbitrarily shaped regions. In this technique, coding efficiency depends on the properties of initial vectors to be orthogonalized. Therefore we adaptively select a set of initial vectors as well as the order in which these vectors are orthogonalized. Simulation results indicate that the proposed coding scheme achieves higher coding performance with much less computation than the KLT-based scheme which we reported formerly.

Stereo Matching Using the Adaptive Patch Based on the Watershed (워터쉐드 기반의 적응 패치를 이용한 스테레오 정합 알고리즘에 관한 연구)

  • Woo-Sung Kil;Jong-Whang Jang
    • The Journal of Engineering Research
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    • v.6 no.2
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    • pp.99-107
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    • 2004
  • In stereo matching system, it is efficient using segment patch, which divides the image into homogeneous region in color or similar intensity, because it preserves the disparity boundary and disparity continuity in low textured region. But many miss matching occur in the highly textured region because of the over segmentation that makes patch small and ambiguous. In this paper, in order to solve problems, we propose adaptive patch matching based on the watershed image segmentation. Performance was verified in experimental results.

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