• 제목/요약/키워드: Boundaries

검색결과 3,806건 처리시간 0.028초

Point defects and grain boundary effects on tensile strength of 3C-SiC studied by molecular dynamics simulations

  • Li, Yingying;Li, Yan;Xiao, Wei
    • Nuclear Engineering and Technology
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    • 제51권3호
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    • pp.769-775
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    • 2019
  • The tensile strength of irradiated 3C-SiC, SiC with artificial point defects, SiC with symmetric tilt grain boundaries (GBs), irradiated SiC with GBs are investigated using molecular dynamics simulations at 300 K. For an irradiated SiC sample, the tensile strength decreases with the increase of irradiation dose. The Young's modulus decreases with the increase of irradiation dose which agrees well with experiment and simulation data. For artificial point defects, the designed point defects dramatically decrease the tensile strength of SiC at low concentration. Among the point defects studied in this work, the vacancies drop the strength the most seriously. SiC symmetric tilt GBs decrease the tensile strength of pure SiC. Under irradiated condition, the tensile strengths of all SiC samples with grain boundaries decrease and converge to certain value because the structures become amorphous and the grain boundaries disappear after high dose irradiation.

블록 동질성 분할을 이용한 화재불꽃 영역 추출에 관한 연구 (A Study on the Fire Flame Region Extraction Using Block Homogeneity Segmentation)

  • 박창민
    • 디지털산업정보학회논문지
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    • 제14권4호
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    • pp.169-176
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    • 2018
  • In this study, we propose a new Fire Flame Region Extraction using Block Homogeneity Segmentation method of the Fire Image with irregular texture and various colors. It is generally assumed that fire flame extraction plays a very important role. The Color Image with fire flame is divided into blocks and edge strength for each block is computed by using modified color histogram intersection method that has been developed to differentiate object boundaries from irregular texture boundaries effectively. The block homogeneity is designed to have the higher value in the center of region with the homeogenous colors or texture while to have lower value near region boundaries. The image represented by the block homogeneity is gray scale image and watershed transformation technique is used to generate closed boundary for each region. As the watershed transform generally results in over-segmentation, region merging based on common boundary strength is followed. The proposed method can be applied quickly and effectively to the initial response of fire.

Microstructural Evolution and Recrystallization Behavior Traced by Electron Channeling Contrast Imaging

  • Oh, Jin-Su;Yang, Cheol-Woong
    • Applied Microscopy
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    • 제48권4호
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    • pp.130-131
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    • 2018
  • Electron channeling contrast imaging (ECCI) is one of the imaging techniques in scanning electron microscopy based on a variation in electron backscattering yield depending on the direction of the primary electron beam with respect to the crystal lattice. The ECCI provides not only observation of the distribution of individual grains and grain boundaries but also identification of the defects such as dislocations, twins, and stacking faults. The ECCI at the interface between recrystallized and deformed region of shot peening treated nickel clearly demonstrates the microstructural evolution during the recrystallization including original grain boundaries, and thus can provide better insight into the recrystallization behavior.

ACOUSTICAL PROPERTIES OF UNDERWATER BUBBLE LAYER WITH TRANSITION SUBLAYERS

  • Sutin, A.M.;Didenkulov, I.N.;Choi, B.K.;Yoon, S.W.
    • 한국음향학회:학술대회논문집
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    • 한국음향학회 1993년도 학술논문발표회 논문집 제12권 1호
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    • pp.190-194
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    • 1993
  • In the ocean bubble layers play a significant role in the sound propagation as well as sound generation. Most of early works dealt with acoustic properties of the bubble layers with sharp flat boundaries. Bubble layers with sharp flat boundaries. Bubble layers with transition sublayers are more likely in the coean. In this paper a theory of sound propagation through plane bubble layers with transition sublayers at both borders was developed. It shows that the reflection and transmission coefficients depend on the thickness of transition sublayers. The theory with thicker transition sublayers shows weaker resonance properties of bubble layer. It gives better presentation for the peculiar behavior of the experimental data than that with sharp flat boundaries.

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동아시아 사유에 있어 의식 공간의 경계 문제 (Boundaries of Conscious Space in East-Asiatic thoughts)

  • 이명수
    • 동양고전연구
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    • 제62호
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    • pp.209-229
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    • 2016
  • 이 논문은 동아시아적 사유를 통해 경계의 의미에 대하여 접근함으로써 경계 담론의 외연을 확장하고자 한다. 사람에게는 우선 '나'라는 '자기 경계'가 있다. 그 몸 경계 속에 정신활동의 경계가 있어서 타자를 대상으로 여기거나 대상을 그려낸다. 동아시아 문화권에서 원초적으로 경계는 국경, 강계(疆界)를 가리키는데, 그것은 물론 불교의 공(空)의 세계를 나타내기도 한다. 경계는 동아시아 사유에서 '인간의 의식이 향하는 곳'이라는 의미가 중요하게 자리 잡고 있고, 그것은 정치, 사회, 문화, 예술 방면에 걸친 것이어서 그리 단편적이지도 않다. 사람에게 생명이 있는 한, 참으로 다가가지 않으면 안 되는 '경계'도 있고, 정신적으로는 욕망, 의지, 관념이 빚어내는 경계도 있다. '경계' 의미에는 사람의 사물 인식 체계에 관계되는 것도 있다. 눈, 코, 입, 귀, 신체 등 오감의 인식 과정에 의한 경계도 있다. 그런 경우라면 다분히 불교적인 맥락에 기초한 사물 인식 차원에 관한 접근인데, 그 같은 인식 시스템에서 발생하는 '경계'는 궁극적이거나 바람직하지 않아서 탈피하지 않으면 안 되는 것도 포함되어 있다. 이 같은 점에 유의하여 경계의 의미, 인간의 의식이 불가피하게 만드는 경계, 부정적인 인식의 경계 등을 성찰하면서 우리가 진정으로 만들어야 하거나 탈피하지 않으면 안 되는 경계 문제를 이 논문은 접근한다.

지적재조사사업지구 내 행정구역경계 합리적 조정방안 - 지적재조사사업 송기지구 중심으로 - (Reasonable Adjustment plan of Administrative boundary for Cadastral Re-examination district - Based on the result of Cadastral resurvey in Songgi-ri -)

  • 김홍열;허태헌;이건수
    • 지적과 국토정보
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    • 제48권2호
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    • pp.31-49
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    • 2018
  • 행정구역 경계는 국가적으로 전반에 미치는 기본제도이며 주민의 일상생활과 밀접한 관련이 있다. 우리나라의 행정 경계선은 지적제도의 지적공부를 바탕으로 지적공부에 등록되어 관리되고 있다. 일부 지적공부의 등록사항이 토지의 실제 현황과 일치하지 아니하는 불부합 토지가 존재하여 국책사업으로 지적재조사사업을 실시하여 새로운 디지털 지적공부를 작성하고 있다. 그러나 지적재조사사업으로 인하여 새로이 등록되는 지적공부에는 과거 행정경계선을 등록하기 때문에 과거 행정경계선과 새로이 등록되는 경계선이 서로 달라지는 불합리한 필지가 발생되는 문제를 가지고 있어 이에 대한 합리적인 행정경계조정이 필요하다. 본 연구에서는 지적재조사사업으로 인하여 발생되는 불합리한 행정경계를 현황을 파악하고 행정 관리적 측면에서 효율적으로 등록과 주민 관리적 측면에서도 효율적인 지번 관리를 위해 문제점을 파악하고 합법적이고 합리적인 행정구역경계 조정방안을 제시하는 것으로 목적으로 한다. 법제도를 정비하여 행정구역경계를 합법적으로 조정하고 이에 따르는 행정구역경계를 원활한 관리와 대국민 불편을 해소와 서비스를 제공하는데 기여할 것으로 판단된다.

차영상을 이용한 웨이브렛 동영상 압축 및 복원 시스템 (Wavelet picture Compression and Decompression system Using Difference Image)

  • 오정태;나지명;김형주;김영민
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 하계종합학술대회 논문집(2)
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    • pp.242-245
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    • 2000
  • In this paper we present new idea to highly compress the images. The previous image is transformed with wavelet and the transformed data are transmitted. The previous image is subtracted from the next image. Then difference values per pixel are scanned to search motion areas and boundaries. In the motion boundaries, motion vectors and error values are transformed with wavelet and transmitted. We also include camera motion estimation and compensation. In this method this system has advantages of more compressive data, better quality of picture and shorter processing time compared to MPEG2, MPEG4.

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Variable length Chromosomes in Genetic Algorithms for Modeling the Class Boundaries

  • Bandyopadhyay, Sanghamitra;Pal, Sankar K.;Murthy, C.A.
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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    • pp.634-639
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    • 1998
  • A methodology based on the concept of variable string length GA(VGA) is developed for determining automatically the number of hyperplanes and their appropriate arrangement for modeling the class boundaries of a given training data set in RN. The genetic operators and fitness functionare newly defined to take care of the variability in chromosome length. Experimental results on different artificial and real life data sets are provided.

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계면의 비파괴 검사 (NDE Detection of Interfaces)

  • 정용무
    • 비파괴검사학회지
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    • 제8권1호
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    • pp.30-37
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    • 1988
  • Interfaces, both grain boundaries and phase boundaries, play a very important role in the mechanical behavior of structural materials. The problemis particularly intense in composite materials where interfaces play a primary role in the meehanical response of the composites. This paper will concentrate on the approaches to perform nondestructive evaluation of the interfaces in a man nor in which some measure of the mechanical behavior of the interface can be established. Some of the possible approaches that may have potential for the nondestructive evaluation of interfaces are optical, electronic/ electrical, and acoustic approaches.

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Prosodic Features at "Sentence Boundaries" in Oral Presentations

  • Umesaki, Atsuko-Furuta
    • 대한음성학회지:말소리
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    • 제41호
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    • pp.83-96
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    • 2001
  • It is generally said that falling intonation is used at the end of a declarative sentence. However, this is not the case with all stretches of spontaneous speech which are marked in transcription as sentences. The present paper examines intonation patterns appearing at the end of declarative sentences in oral presentations, and discusses instances where falling intonation does not appear. The texts used for analysis are eight oral presentations collected at international conferences in the field of physics. Quantitative and qualitative analyses are carried out. Three major factors related to discourse structure have been found for non-occurrence of falling intonation at sentence boundaries.

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