• 제목/요약/키워드: lattice structure

검색결과 1,132건 처리시간 0.026초

A study on a collective behavior of interacting simple robots

  • Sugawara, Ken;Sano, Masaki;Watanabe, Toshinori
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2002년도 ICCAS
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    • pp.93.6-93
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    • 2002
  • Many livings form groups that we consider as collective systems. Their collective behaviors are good model for the development of useful distributed systems. In this paper, We discussed the group of motile elements that is described by simple model. The dynamics of each element is described by simple kinematics, but the group shows various types of motions. In addition, we found out the formation of the group changes by modifying rc which is an optimum distance between each element. This modification shows us to observe close-packed structure, face-centered lattice, sim pie lattice and double file.

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디지털 가입자회선을 위한 효율적인 반향 제거기 (An Efficient Echo Canceller for Digital Subscriber Lines)

  • 권오상;박현철
    • 한국통신학회논문지
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    • 제26권9B호
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    • pp.1209-1214
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    • 2001
  • 본 논문에서는 양방향 디지털 가입자 회선 (Digital Subscriber Lines) 통신을 위해 격자 구조 (lattice structure)와 직교화된 IIR 형태의 필터가 결합된, 이른바 CALAOI(CAscade of LAttice and Orthogonalized IIR) 구조를 갖는 새로운 반향제거기를 제안한다. 모의실험을 통하여 CALAOI 반향제거기는 기존의 FIR 및 IIR 반향제거기보다 훨씬 적은 계산량 및 메모리, 그리고 빠른 수렴속도를 갖는 안정적인 반향제거기임을 확인할 수 있었다. CALAOI 반향 제거기는 xDSL뿐만 아니라, GIGA-bit Ethernet 등 고속 양방향 통신에서 서비스의 성능을 극대화하는데 크게 기여할 것으로 예상된다.

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초음파의 전파, 반사, 산란 현상에 대한 수치 시뮬레이션 (Numerical study of propagation, reflection, and scattering of ultrasonic waves)

  • 임현준
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2002년도 봄 학술발표회 논문집
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    • pp.401-406
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    • 2002
  • A numerical model is introduced to simulate propagation, reflection, and scattering of elastic waves in solids. The model consists of mass points and linear springs, interconnected with in a lattice structure; hence, its name, the mass-spring lattice model (MSLM). The MSLM has successfully been applied to the numerical simulation and visualization of various elastic wave phenomena involved in ultrasonic nondestructive testing (NDT). This method is useful to simulate, design, or analyze actual testing. Some representative examples of numerical simulation using the MSLM are presented, and future work necessary for its further development Is addressed.

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Lattice Vibrational Calculation of Orthorhombic Hydrogne Chloride

  • 노경태;전무식
    • Bulletin of the Korean Chemical Society
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    • 제6권4호
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    • pp.183-186
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    • 1985
  • The lattice vibrational calculation of orthorhombic hydrogen chloride is performed using physically realistic potential function which can reproduce the X-ray structure and heat of sublimation of the low temperature phase. The polar coordinates representation is introduced in order to describe the intermolecular interactions in a molecular crystal. The splitting in internal modes is calculated as 49 $cm^{-1}$ and the other modes are in good agreement with experimental results.

Mg-Zn-Y 합금에서 준결정 및 준결정 유사상 (Quasicrystals And Related Approximant Phases in Mg-Zn-Y)

  • 박은수;옥재범;김원태;김도향
    • Applied Microscopy
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    • 제32권1호
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    • pp.31-37
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    • 2002
  • [ $Mg_{68}Zn_{28}Y_4$ ] 합금의 응고 조직은 primary solidification phase, primary solidification phase로부터 성장된 ${\alpha}-Mg$ dendrite, 그리고 응고 말기에 형성된 eutectic structure의 세 가지형태 조직으로 구성되어져 있다. Primary solidification phase에는 매우 큰 정도의 phason strain이 존재하고 있으며, $a=27.2{\AA}\;and\;{\alpha}=63.43^{\circ}$의 격자상수를 갖는 1/1 rhombohedral approximant가 존재한다. 이와 같은 rhombohedral approximant의 구조는 six dimensional face centered hyper-cubic lattice에 phason strain을 도입함에 의해 얻어질 수 있다. Decagonal phase는 icosahedral phase로부터 방위 관계를 가지며 형성되며, $Mg_4Zn_7$는 decagonal phase로부터 방위관계를 가지며 성장한다. 이는 세 상간에 구조적 유사성이 존재하고 있음을 의미하며, 응고시 용질원자의 분배에 의해 이들 세 상이 순서대로 형성되어진다.

EXTREMAL STRUCTURE OF B($X^{*}$)

  • Lee, Joung-Nam
    • 한국수학교육학회지시리즈B:순수및응용수학
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    • 제5권2호
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    • pp.95-100
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    • 1998
  • In this note we consider some basic facts concerning abstract M spaces and investigate extremal structure of the unit ball of bounded linear functionals on $\sigma$-complete abstract M spaces.

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A Note on Computing the Crisp Order Context of a Fuzzy Formal Context for Knowledge Reduction

  • Singh, Prem Kumar;Kumar, Ch. Aswani
    • Journal of Information Processing Systems
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    • 제11권2호
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    • pp.184-204
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    • 2015
  • Fuzzy Formal Concept Analysis (FCA) is a mathematical tool for the effective representation of imprecise and vague knowledge. However, with a large number of formal concepts from a fuzzy context, the task of knowledge representation becomes complex. Hence, knowledge reduction is an important issue in FCA with a fuzzy setting. The purpose of this current study is to address this issue by proposing a method that computes the corresponding crisp order for the fuzzy relation in a given fuzzy formal context. The obtained formal context using the proposed method provides a fewer number of concepts when compared to original fuzzy context. The resultant lattice structure is a reduced form of its corresponding fuzzy concept lattice and preserves the specialized and generalized concepts, as well as stability. This study also shows a step-by-step demonstration of the proposed method and its application.

이온성 크러스레이트 하이드레이트의 격자 수축 거동 (Lattice Contraction Behavior Occurring in Ionic Clathrate Hydrate)

  • 권민철;차민준;신규철;이흔
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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    • pp.150.2-150.2
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    • 2011
  • Unlike non-ionic clathrate hydrates stably formed by van der Waals interaction between a guest molecule and a surrounding host framework, ionic clathrate hydrates are stabilized by ionic interaction between an ionic guest molecule and the host water-framework. Here, we firstly described the stable entrapment of the superoxide ions in ${\gamma}$-irradiated $Me_4NOH+O_2$ hydrate. Owing to peculiar direct guest-guest ionic interaction, the lattice structure of ${\gamma}$-irradiated $Me_4NOH+O_2$ hydrate shows significant change of lattice contraction behavior even at relatively high temperature(120K). Particularly, we note that ionic-induced dimensional change is much greater than thermal-induced change. Such findings are expected to provide useful information for a better understanding of unrevealed nature of clathrate hydrate fields.

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유도결합형 플라즈마 식각공정을 통해 제작된 460 nm 격자를 갖는 나노 광결정 특성 (Fabrication of Nano-photonic Crystals with Lattice Constant of 460-nm by Inductively-coupled Plasma Etching Process)

  • 최재호;김근주
    • 반도체디스플레이기술학회지
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    • 제5권2호
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    • pp.1-5
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    • 2006
  • The GaN thin film on the 8 periods InGaN/GaN multi-quantum well structure was grown on the sapphire substrate using metal-organic chemical vapor deposition. The nano-scaled triangular-lattice holes with the diameter of 150 nm were patterned on a polymethylmethacrylate blocking film using an electron beam nano-lithography system. The thin slab and two-dimensional photonic crystals with the thickness of 28 nm were fabricated on the GaN layer for the blue light diffraction sources. The photonic crystal with the lattice parameter of 460 nm enhances spectral intensity of photoluminescence indicating that the photonic crystals provides the source of nano-diffraction for the blue light of the 450-nm wavelength.

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