• Title/Summary/Keyword: Boundaries

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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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    • v.51 no.3
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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.

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

  • Park, Changmin
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.14 no.4
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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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    • v.48 no.4
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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.
    • Proceedings of the Acoustical Society of Korea Conference
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    • 1993.06a
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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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Boundaries of Conscious Space in East-Asiatic thoughts (동아시아 사유에 있어 의식 공간의 경계 문제)

  • Rhee, Myung-Su
    • (The)Study of the Eastern Classic
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    • no.62
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    • pp.209-229
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    • 2016
  • This thesis is to discover the meanings of boundary through East Asian thought so as to make rooms for discoursing on it. First of all people have their own boundaries of 'Me', and they make others as persons or objects in their thoughts. Originally boundary has represented nation's frontier, and it indicated the worlds of space in Buddhism of East Asian culture. It is represented by loka or visaya in Sanskrit and region, dominion, boundary, border in English, which means the worlds that people would fancy in their minds over domains of politics, societies, culture, arts ect, not to be simple. Accordingly we must not approach to its meaning simply like 'beyond border'. There are many boundaries, which are similar to the sublime, for us to arrive in our lives. Spiritually there are also many boundaries(regions) that are made by our desires, wills and concepts. In a while there are limit or problem in our recognizing things, for example, of human's five senses that would be, to an extent connected with Buddhistic understanding of boundaries. Boundaries resulted from partiality in understanding of objects must be got rid of eventually. In regard of these matters, this thesis discusses the meanings of boundary, those that are inevitably made by human's consciousness, and negative ones to be got over from recognition systems of person or any groups.

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

  • Kim, Honng-Ryeol;Heo, Tae-Heon;Lee, Keon-soo
    • Journal of Cadastre & Land InformatiX
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    • v.48 no.2
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    • pp.31-49
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    • 2018
  • The boundaries of administrative districts are the basic system for the whole country and are closely related to the daily life of the residents. The administrative boundary of Korea is registered and managed in the cadastral study based on the intellectual study of cadastral system. There is a non-conforming land where the registration details of some cadastral studies do not match the actual situation of the land, and the cadastral rehabilitation project is implemented as a national project to create a new digital cadastral study. However, due to the cadastral rehabilitation project, there is an unreasonable parcel that the past administrative boundaries and newly registered boundaries are different from each other due to the registration of the past administrative boundaries for the newly registered cadastral studies. The purpose of this study is to identify the unreasonable administrative boundaries arising from the cadastral rehabilitation project and to identify problems in order to effectively manage the number of branches in terms of administrative and administrative efficiency in terms of registration and inhabitants management. It is expected that the legal system will be improved to legitimately control the boundary of the administrative district and to manage the boundaries of the administrative district accordingly and to provide the service and to solve the inconvenience of the nation.

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

  • 오정태;나지명;김형주;김영민
    • Proceedings of the IEEK Conference
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    • 2000.06b
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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.
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1998.06a
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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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NDE Detection of Interfaces (계면의 비파괴 검사)

  • Cheong, Y.M.
    • Journal of the Korean Society for Nondestructive Testing
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    • v.8 no.1
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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
    • MALSORI
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    • no.41
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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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