• 제목/요약/키워드: Infinite element

검색결과 330건 처리시간 0.028초

음향 탄성영상법에서 연조직 내 파동 발생과 병변 검출의 특성: 이론 및 시뮬레이션 연구 (Wave Generation and Its Effect on Lesion Detection in Sonoelastography: Theory and Simulation Study)

  • 박정만;권성재;정목근
    • 한국음향학회지
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    • 제24권5호
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    • pp.282-293
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    • 2005
  • 음향 탄성영상법은 외부 진동을 조직에 인가하고 조직 운동을 측정함으로써 조직의 탄성을 영상화하는 초음파영상기법이다. 본 논문에서는 음향 탄성영상법에서 표면 진동자에 의해 연조직 내에 파동이 발생되는 특성과 모드패턴이암과 같은 병변 검출에 미치는 영향을 조사였다. 이를 위해 반공간, 두께가 일정한 무한평판, 그리고 유한 크기 조직에서 발생된 진동패턴을 이론과 유한요소법으로 계산하고 분석하였다. 유한 너비 진동원에 의해 조직에는 특정한 방향으로 강하게 전달되는 횡파가 발생하였으며, 그 특성은 진동자 너비, 주파수 및 진동자로부터의 거리에 의존하였다. 유한 크기 조직에서 병변의 검출가능성은 변위영상에서는 조직내 모드패턴에 큰 영향을 받았으며, 이에 비해 변형률영상에서는 모드패턴에 덜 민감하고 검출가능성도 아주 높은 것으로 나타났다.

하이브리드의 탈 장르화를 응용한 메이크업 디자인에 관한 연구(제 1보) (A Study on of Make-up Design with the Application of Genre Deconstruction in Hybrids (Ver. 1))

  • 방기정;김경희
    • 복식문화연구
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    • 제20권3호
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    • pp.347-362
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    • 2012
  • Formatively and artistically aspect, a hybrid can be said to be a phenomenon in which two mutually different genres are combined. Make-up is thought to be very important to arrange the foundation available for predicting and pursuing a flow and direction of future hybrid make-up based on this, by analyzing a flow centering on hybrid trend, which was shown previously. In terms of objectives of this study, the first, aim is to suggest a model for researching make-up by grasping the developmental process and the characteristics of hybrid art through considering an art theory of hybridity, shown in make-up. The second, aim is to design make-up by analyzing trends in make-up style after deconstructing the hybrid genre. The modern make-up design through genre-deconstruction characteristics beyond diverse plurality and genre could be known to be highlighted as aesthetic characteristic by a slight attempt as communication of open space, which connects culture and genre, which had failed to be recognized and was neglected. Empirical research has, produced a work by systematically arranging make-up design. This study, identifies two kind of barrier demolition, such as the class deconstruction and the temporal, spatial disorder centering on genre deconstruction of hybrid. There are infinite possibilities in developing make-up design in line with modern sensation through aesthetic element and symbolic significance through genre deconstruction. It was the expression mode in future make-up, to providing basic data, and to strengthening competitive edge of culture and art.

하이브리드의 탈 장르화를 응용한 메이크업 디자인에 관한 연구(제 2보) (A Study on Make-up Design with Application of Genre Deconstruction in Hybrid(Ver. 2))

  • 방기정;김경희
    • 패션비즈니스
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    • 제16권2호
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    • pp.88-107
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    • 2012
  • Hybrid implies that elements in more than two are combined, and is what is merged and used complexly the technologies and materials in several fields according to the development in scientific technology and the progress in technology. In the formative and artistic aspect, the hybrid can be said to be phenomenon that two of mutually different genres are combined. The function and form in each genre, which were combined at this time, are remained wholly or partially, thereby revealing as well without hiding a fact of having been combined. In the digital communication era, the same time level was integrated into one culture, with destroying the temporal·spatial boundary. As for the objectives of this study, first, the aim is to suggest a model for researching into make-up by grasping the developmental process and the characteristics of hybrid art through considering an art theory of hybrid, which was shown in make-up. Second, the aim is to design make-up by analyzing trend by make-up style after applying the genre deconstruction in hybrid. The modern make-up design through genre-deconstruction characteristics beyond diverse plurality and genre could be known to be highlighted as aesthetic characteristic by a slight attempt as communication of open space, which connects culture and genre, which had failed to be recognized and was neglected. Through the results of this study, it could be known that there is infinite possibility in developing make-up design in line with modern sensation through aesthetic element and symbolic significance through genre deconstruction. Based on these findings, its significance can be said to be in substantially contributing to offering new sight to the design & formative characteristic and the expression mode in future make-up, to providing basic data, and to strengthening competitive edge of culture and art.

AC transport current loss analysis for anti-parallel current flow in face-to-face stacks of superconducting tapes

  • Yoo, Jaeun;Han, Young-Hee;Kim, Hey-Rim;Park, Byung-Jun;Yang, Seong-Eun;Kim, Heesun;Yu, Seung-Duck;Park, Kijun
    • 한국초전도ㆍ저온공학회논문지
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    • 제16권2호
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    • pp.42-46
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    • 2014
  • In this study we investigated ac transport current losses in the face to face stack for the anti-parallel current flow, and compared the electromagnetic properties with those of the single SC tape as well as those of the same stack for the parallel current path. The gap between the SC tapes in the stack varied in order to verify the electromagnetic influence of the neighbors when current flows in opposite direction, and the model was implemented in the finite element method program by the commercial software, COMSOL Multiphysics 4.2a. Conclusively speaking, the loss was remarkably decreased for the anti-parallel current case, which is attributed the magnetic flux compensation between the SC layers due to the opposite direction of the current flows. As the gap between SC tapes was increased, the loss mitigation became less effective. Besides, the current density distribution is very flat cross the sample width for the narrower gap case, which is believed to be benefit for the power electric system. These results are all in good agreement with those predicted theoretically for an infinite bifilar stack.

XSLT를 이용한 B2B 기반의 통합형 e-Catalog 변환 및 관리 시스템 구현 (The Implementation of Integrated e-Catalog Transformation and Management System based on B2B using XSLT)

  • 김윤기;김창수;정회경
    • 한국정보통신학회논문지
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    • 제7권7호
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    • pp.1582-1589
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    • 2003
  • 기업과 기업(B2B)간 또는 기업과 소비자(B2C)간의 전자 상거래를 위하여 상품 및 서비스에 대한 정보를 전자적인 형태로 교환하기 위한 전자 문서를 e-Catalog라고 하며, 전자 상거래에 이용되는 e-Catalog는 무한한 인터넷 공간에서 효과적으로 기업의 상품 및 제품의 특성을 잘 표현할 수 있는 중요한 요소이다. 하지만 전자 상거래에 사용되고 있는 e-Catalog 시스템은 명확한 개념과 일관된 구성요소 등이 없고 서로 상이한 시스템을 구축하고 있으며 이로인해 e-Catalog 정보를 교환 및 거래에 사용할 수 없는 단점이 있다. 이에 본 논문에서는 이기종 시스템에서 상호 운용성을 증대시키기 위하여 XML Schema를 이용하여 통합적으로 상품 정보를 처리 할 수 있는 e-Catalog 문서 구조를 정의하였다. 또한 XML로 정의된 e-Catalog 문서를 XSLT를 이용하여 다른 구조의 e-Catalog 문서로 변환하고 관리할 수 있는 통합형 e-Catalog 시스템을 설계 및 구현하였다.

여러 종류의 표면 진동원에 대한 연조직에서의 진동 변위 비교 (Comparison of Vibrational Displacements Generated by Different Types of Surface Source in a Soft Tissue)

  • 박정만;권성재;정목근
    • 비파괴검사학회지
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    • 제32권5호
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    • pp.469-483
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    • 2012
  • 인체 연조직에서 기계적인 진동의 전달 특성은 조직의 탄성 특성에 의존한다. 연조직의 진동 특성으로부터 암이나 종양을 진단할 수 있기 때문에 진동의 전달 특성에 대한 연구는 중요한 의미를 가진다. 이 논문은 연조직의 표면에 위치하는 여러 형태의 응력 진동원에 의해 연조직 내에 발생되는 변위 패턴을 분석하고 비교하였다. 진동원으로는 수직하중, 접선하중, 그리고 면외전단하중이 고려되었다. 점탄성 단일층에서의 변위에 대한 이론적 표현식을 구하였고, 수치계산은 반공간 및 무한평판조직에서 수행되었다. 그리고 유한크기조직에서의 변위패턴을 유한요소법으로 시뮬레이션하였다. 응력 형태, 진동원 크기 및 주파수, 그리고 경계면이 변위에 미치는 영향이 분석되었다.

수중익에 의한 비선형 조파현상의 수치해석 (Numerical Computations for Hydrofoil-Generated Nonlinear Waves)

  • 이홍기;배광준
    • 대한조선학회논문집
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    • 제30권3호
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    • pp.29-40
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    • 1993
  • 본 연구는 정수면으로 부터 얕게 잠겨 항주하는 3차원 수중익에 의한 비선형 조파현상의 특성규명을 위한 기초연구로서 수중익이 예인수조안에서 일정속도로 항주할 때 자유표면에 발생하는 비선형 파형의 특성과 수중익에 작용하는 유체력을 계산하기 위한 수치해법의 개발을 목적으로 하였다. 수치해법으로는 변분원리에 기초한 유한요소법올 사용하였으며 수중익 근처에서는 비선형 자유표면조건을 엄밀하게 만족시켰고 수중익으로 부터 충분히 떨어진 영역에서는 종래의 선형화된 자유표면 경계조건을 만족시켰다. 수치해법의 계산효율을 높이기 위하여 비선형영역과 선형영역 사이에 인위적인 비선형-선형 완충영역을 도입하여 계산영역을 크게 줄였다. 수중익을 간단한 직사각형 보오텍스계로 표현하여 유속과 몰수길이, 보오텍스의 세기 및 분포의 변화에 따른 비선형 파형의 특성을 조사하였으며 특히 자유 보오텍스선이 비선형 파형에 미치는 영향을 파악하였다. 파동에 의하며 수중익에 유기되는 속도성분들의 크기 및 분포, 양력 및 유기항력에 대한 계산을 수행하여 자유표면의 비선형성에 의한 영향을 규명하였다.

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3층 철근콘크리트 전단벽 구조물의 지진응답해석 (Earthquake Response Analysis for Three-Story Building with Reinforced Concrete Shear Walls)

  • 이인규;이은행;김재민
    • 한국지진공학회논문집
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    • 제25권3호
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    • pp.103-110
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    • 2021
  • A shake table test is conducted for the three-story reinforced concrete building structure using 0.28 g, 0.5 g, 0.75 g, and 1.0 g of seismic input motions based on the Gyeongju earthquake. Computational efforts are made in parallel to explore the mechanical details in the structure. For engineering practice, the elastic modulus of concrete and rebar in the dynamic analysis is reduced to 38% and 50%, respectively, to calibrate the structure's natural frequencies. The engineering approach to the reduced modulus of elasticity is believed to be due to the inability to specify the flexibility of the actual boundary conditions. This aspect may lead to disadvantages of nonlinear dynamic analysis that can distort local stress and strain relationships. The initial elastic modulus can be applied directly without the so-called engineering adjustment with infinite element models with spring and spring-dashpot boundary conditions. This has the advantage of imposing the system flexibility of the structure on the sub-boundary conditions of springs and damping devices to control its sensitivity in a serial arrangement. This can reflect the flexibility of realistic boundary conditions and the effects of system damping (such as the gap between a concrete footing and shake table, loosening of steel anchors, etc.) in scalar quantities. However, these spring and dashpot coefficients can only be coordinated based on experimental results, making it challenging to select the coefficients in-prior to perform an experimental test.

표면 니켈 조성에 따른 팔라듐-니켈-은 합금 수소분리막의 수소투과선택 특성 (Hydrogen Perm-Selectivity Properties of the Pd-Ni-Ag Alloy Hydrogen Separation Membranes with Various Surface Nickel Composition)

  • 임다솔;김세홍;김도희;조서현;김동원
    • 한국표면공학회지
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    • 제51권5호
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    • pp.277-290
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    • 2018
  • In this study, Pd-Ni-Ag alloy hydrogen separation membranes were fabricated by Pd/Ag/Pd/Ni/Pd multi-layer sputter deposition on the modified MIM(Metal Injection Molding)-PSS(Porous Stainless Steel) support and followed heat treatment. Nickel, used as an alloying element in Pd alloy membranes, is inexpensive and stable material in a hydrogen isotope environment at high temperature up to 1123 K. Hydrogen perm-selectivity of Pd-Ni-Ag alloy membranes is affected not only by composition of membrane films but also by other factors such as surface properties of PSS support, microstructure of membrane films and inter-diffused impurities from PSS support. In order to clarify the effect of surface Ni composition on hydrogen perm-selectivity of Pd-Ni-Ag alloy membranes, the other effects were significantly minimized by the formation of dense and homogeneous Pd-Ni-Ag alloy membranes. Hydrogen permeation test showed that hydrogen permeability decreased from $7.6{\times}10^{-09}$ to $1.02{\times}10^{-09}mol/m{\cdot}s{\cdot}Pa^{0.5}$ as Ni composition increased from 0 to 16 wt% and the selectivity for $H_2/N_2$ was infinite.

Effects of inclined bedrock on dissimilar pile composite foundation under vertical loading

  • Kaiyu, Jiang;Weiming, Gong;Jiang, Xu;Guoliang, Dai;Xia, Guo
    • Geomechanics and Engineering
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    • 제31권5호
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    • pp.477-488
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    • 2022
  • Pile composite foundation (PCF) has been commonly applied in practice. Existing research has focused primarily on semi-infinite media having equal pile lengths with little attention given to the effects of inclined bedrock and dissimilar pile lengths. This investigation considers the effects of inclined bedrock on vertical loaded PCF with dissimilar pile lengths. The pile-soil system is decomposed into fictitious piles and extended soil. The Fredholm integral equation about the axial force along fictitious piles is then established based on the compatibility of axial strain between fictitious piles and extended soil. Then, an iterative procedure is induced to calculate the PCF characteristics with a rigid cap. The results agree well with two field load tests of a single pile and numerical simulation case. The settlement and load transfer behaviors of dissimilar 3-pile PCFs and the effects of inclined bedrock are analyzed, which shows that the embedded depth of the inclined bedrock significantly affects the pile-soil load sharing ratios, non-dimensional vertical stiffness N0/wdEs, and differential settlement for different length-diameter ratios of the pile l/d and pile-soil stiffness ratio k conditions. The differential settlement and pile-soil load sharing ratios are also influenced by the inclined angle of the bedrock for different k and l/d. The developed model helps better understand the PCF characteristics over inclined bedrock under vertical loading.