• Title/Summary/Keyword: Boundary Refining

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Segmentation of the Liver in CT using Morphological Filters (형태학적 필터를 이용한 CT 영상에서 간 영역 분할 기법)

  • 임성재;정용연;이칠우;호요성
    • Proceedings of the IEEK Conference
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    • 2003.11b
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    • pp.153-156
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    • 2003
  • In this paper, we propose a new scheme for automatic segmentation of the liver in CT images. The proposed scheme is carried out on region of interest(ROI) blocks that include regions of the liver with high probabilities. The ROI approach saves unnecessary computational loss in finding the accurate boundary of the liver. The proposed method utilizes the composition of multi-size morphological filters with a prior knowledge, such as the general location or the approximate intensity of the liver to detect the initial boundary of the liver. Then, we make the gradient image with the weight of the initial liver boundary and segment the liver legion by using an immersion-based waters hed algorithm in the gradient image. finally, the refining process is carried out to acquire a more accurate liver region.

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Extraction Process of Lead and Variations of Physicochemical Properties using the Smelting Experiment of Galena (방연석 제련실험을 통한 납 추출과정 및 물리화학적 거동변화 연구)

  • Han, Woo-Rim;Kim, So-Jin;Lee, Eun-Woo;Hwang, Jin-Ju;Kim, Su-Ki;Han, Min-Su
    • Journal of Conservation Science
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    • v.29 no.1
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    • pp.69-79
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    • 2013
  • This study aims at identifying the variation of physicochemical properties for galena ore in order to use it in understanding of manufacturing techniques in terms of metallurgical method and smelting or refining process for obtaining lead. The ores in the study obtained from the operating mine have been washed and pre-treated for a test. Metallic lead has been extracted by roasting process. The result displays that galena is still in present in the matt despite of exposure to high temperature, over $1000^{\circ}C$. Nearly $11.1g/cm^3$ specific gravity metallic lead has been collected from the refining test of which aim was to remove the remnant galena and a trace of concentrated silver has been identified at the grain boundary. The result suggests that at least one refining process was essential to acquire high purity metallic lead and cupellation had been executed to remove remnant silver.

Lip Shape Representation and Lip Boundary Detection Using Mixture Model of Shape (형태계수의 Mixture Model을 이용한 입술 형태 표현과 입술 경계선 추출)

  • Jang Kyung Shik;Lee Imgeun
    • Journal of Korea Multimedia Society
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    • v.7 no.11
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    • pp.1531-1539
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    • 2004
  • In this paper, we propose an efficient method for locating human lips. Based on Point Distribution Model and Principle Component Analysis, a lip shape model is built. Lip boundary model is represented based on the concatenated gray level distribution model. We calculate the distribution of shape parameters using Gaussian mixture. The problem to locate lip is simplified as the minimization problem of matching object function. The Down Hill Simplex Algorithm is used for the minimization with Gaussian Mixture for setting initial condition and refining estimate of lip shape parameter, which can refrain iteration from converging to local minima. The experiments have been performed for many images, and show very encouraging result.

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A New Method for Segmenting Speech Signal by Frame Averaging Algorithm

  • Byambajav D.;Kang Chul-Ho
    • The Journal of the Acoustical Society of Korea
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    • v.24 no.4E
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    • pp.128-131
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    • 2005
  • A new algorithm for speech signal segmentation is proposed. This algorithm is based on finding successive similar frames belonging to a segment and represents it by an average spectrum. The speech signal is a slowly time varying signal in the sense that, when examined over a sufficiently short period of time (between 10 and 100 ms), its characteristics are fairly stationary. Generally this approach is based on finding these fairly stationary periods. Advantages of the. algorithm are accurate border decision of segments and simple computation. The automatic segmentations using frame averaging show as much as $82.20\%$ coincided with manually verified segmentation of CMU ARCTIC corpus within time range 16 ms. More than $90\%$ segment boundaries are coincided within a range of 32 ms. Also it can be combined with many types of automatic segmentations (HMM based, acoustic cues or feature based etc.).

Effects of Zn, Zr Addition on Microstructures and Hardness of Mg/SiCp Composites Fabricated by Rheo-Compocasting (Rheo-Compocasting법으로 제조한 Mg/SiCp 복합재료의 조직 및 경도 특성에 미치는 Zn, Zr 첨가의 영향)

  • Hong, Sung-Kil;Choe, Jung-Chul
    • Journal of Korea Foundry Society
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    • v.15 no.6
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    • pp.588-595
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    • 1995
  • SiC particles reinforced Mg-Zr, Mg-Zn and Mg-Zn-Zr composites were manufactured by Rheocompocasting method. Effects of Zn, Zr addition on microstructures and hardness were investigated by using the micro Vickers hardness tester, the optical and scanning electron microscopy. By the Zr addition to the pureMg/SiCp composites, SiC particles become more homogeneously dispersed and grain refined so that the micro hardness of the composite increased. In case of Zn addition, although grain refinement and homogeneous dispersion effects of SiC particles were not obtained, hardness was more increased than the only Zr added composite by the formation of many Mg-Zn intermetallic compounds at grain boundary. In the Mg-Zn-Zr/SiCp composite, the highest value of hardness was obtained by triple effects such as grain refining, dispersion hardening of SiC particles and Mg-Zn compounds.

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Evaluation of ferritic stainless steel FCA overlay weld metal ductility (페라이트계 스테인리강의 FCA 육성용접부 연성 평가)

  • Kim Yeong-Il;Choi Jun-Tae;Kim Dae-Sun
    • Proceedings of the KWS Conference
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    • 2006.05a
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    • pp.140-142
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    • 2006
  • The bend ductility of Type 410S ferritic stainless steel overlay weld on carbon steel was investigated. Overlay weld that was stabilized with Nb had large columnar ferrite grain and Nb precipitate on grain boundary. And that caused fracture when bend test without concern of PWHT condition. Proper bend ductility at as-welded condition was achieved by refining ferrite grain with addition of $0.04{\sim}0.09%$ Al and $0.2{\sim}0.5%$ Ti that make oxide, carbide and nitride at high temperature.

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Development of finite element numerical simulation for three-dimensional oxidation (3차원 산화 공정을 위한 유한요소법 수치 해석기 개발에 관한 연구)

  • 이제희;윤상호;송재복;김윤태;원태영
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.34D no.3
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    • pp.74-86
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    • 1997
  • With continued miniaturization and development of new devices, the highly nonuniform oxidation of three-dimensional non-planar silicon structures plays an increasingly important role. In this paper, the three-dimensional finite element numerical simulator. Grwoth of oxide is a coupled process of diffusion of oxidant and deformation of oxide. Because boundaries of oxide are moved in each time step and LOCOS structure is formed three-dimensional shape of sruface, it is necessary to develope an efficient node control algorithm that can locally generate and eliminate the node. Therefore we have developed the optimized three-dimensional mesh generator which is cpable of refining and eliminating the meshes at the moving boundary of oxide, and hve developed three-dimensional finite element oxidation solver.

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Refinement of Ground Truth Data for X-ray Coronary Artery Angiography (CAG) using Active Contour Model

  • Dongjin Han;Youngjoon Park
    • International journal of advanced smart convergence
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    • v.12 no.4
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    • pp.134-141
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    • 2023
  • We present a novel method aimed at refining ground truth data through regularization and modification, particularly applicable when working with the original ground truth set. Enhancing the performance of deep neural networks is achieved by applying regularization techniques to the existing ground truth data. In many machine learning tasks requiring pixel-level segmentation sets, accurately delineating objects is vital. However, it proves challenging for thin and elongated objects such as blood vessels in X-ray coronary angiography, often resulting in inconsistent generation of ground truth data. This method involves an analysis of the quality of training set pairs - comprising images and ground truth data - to automatically regulate and modify the boundaries of ground truth segmentation. Employing the active contour model and a recursive ground truth generation approach results in stable and precisely defined boundary contours. Following the regularization and adjustment of the ground truth set, there is a substantial improvement in the performance of deep neural networks.

Efficacy Analysis of Developed Course for Promoting Character Education with Women's University Students (대학교의 인성교육진흥을 위한 교양교과 개발 및 효과성 연구)

  • Kim, Ji-Won
    • Journal of Digital Convergence
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    • v.13 no.11
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    • pp.481-491
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    • 2015
  • This research has verified the efficacy of character education course in Liberal Art Curriculum in accordance with the objective of K Women's University of which is the 'mind sharing through mindfulness, SMART human resources development'. Most of the content of character education is organized aiming to promote values of "appreciation". The subjects are experimental group and control group, of which are 229. Research methods were t-test of between groups. The effects of the course have shown that the experimental group students were higher on the level of connectedness sub-scale in Gestalt Contact Boundary Scale than those of the control group students(t=2.323, p = .021). Although the 'character education' course increased connectedness, but it no positive effect on mindfulness skill and self-esteem. This results showed that character education course is effective to promote mind sharing and connectedness in part. It was discussed about a way of further refining course contents and the need to reflect educational philosophy of the K Women's University.

Variation of Microstructure and Property of the Electro-slag Remelted M2 Steel with Heat Treatment Conditions (ESR한 M2강의 열처리에 따른 미세조직 및 물성 변화)

  • Lee, Ki-Jong;Kim, Moon-Hyun;Lee, Jeong-Keun;Joo, Dae-Heon;Kim, Myung-Ho
    • Journal of Korea Foundry Society
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    • v.22 no.6
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    • pp.281-287
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    • 2002
  • In order to investigate the variation of microstructure and property of the Electro-slag Remelted M2 steel, microstructure observation, hardness, and bending test were performed by using optical microscope. SEM/EDS, rockwell hardness tester, charpy impact tester and bending tester, respectively. It was revealed that the number of inclusions and content of gas elements(S, O, N) in M2 steel fabricated by ESR process decreased markedly compared to those of AIM. It seems to be due to refining effect of ESR process. The volume fraction of carbides in quenched and tempered specimens after austenitizing at 1150$^{\circ}C$ and 1240$^{\circ}C$ was measured. The volume fraction of grain boundary carbides were found to be similar for both specimens. However, The volume fraction of carbides in grain decreased with an increase of austenitizing temperature. When specimen was austenitized at 1150$^{\circ}C$, grain boundary carbides showed needle like morphology. But, the carbides were broken with an increase of austenitizing temperature. The specimen austenitized at 1240$^{\circ}C$ showed higher hardness and lower bending strength compared to that of 1150$^{\circ}C$. As expected, toughness increased with sub-zero quenching treatment.