• 제목/요약/키워드: Concept lattice

검색결과 101건 처리시간 0.029초

$\beta$-COMPACTNESS IN L-FUZZY TOPOLOGICAL SPACES

  • Cho, S.H;Kim, M.Y
    • Journal of applied mathematics & informatics
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    • 제9권1호
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    • pp.359-370
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    • 2002
  • The purpose of this paper is to introduce and discuss the concept of $\beta$-compactness for L-fuzzy topological spaces.

Incremental Model-based Test Suite Reduction with Formal Concept Analysis

  • Ng, Pin;Fung, Richard Y.K.;Kong, Ray W.M.
    • Journal of Information Processing Systems
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    • 제6권2호
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    • pp.197-208
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    • 2010
  • Test scenarios can be derived based on some system models for requirements validation purposes. Model-based test suite reduction aims to provide a smaller set of test scenarios which can preserve the original test coverage with respect to some testing criteria. We are proposing to apply Formal Concept Analysis (FCA) in analyzing the association between a set of test scenarios and a set of transitions specified in a state machine model. By utilizing the properties of concept lattice, we are able to determine incrementally a minimal set of test scenarios with adequate test coverage.

다중 송수신 안테나 시스템에서 적응 K-best 검출 알고리즘 (An Adaptive K-best detection algorithm for MIMO systems)

  • 김종욱;강지원;이충용
    • 대한전자공학회논문지TC
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    • 제43권10호
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    • pp.1-7
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    • 2006
  • 다중 송수신 안테나 시스템에서 비트 오류 확률 성능면에서 최적의 기법으로 알려진 ML(Maximum-Likelihood) 복호기를 구현하기 위해 격자 복호 기법이 제안되었다. 그러한 격자 복호 기법에 기반한 복호기에는 구 복호기, K-best 복호기 등이 있으며, K-best 검출 기법은 격자 복호 기법의 실제 구현에 가장 적합하지만 오차 전달 현상에 의한 성능 저하라는 단점이 있다. 본 논문에서는 이러한 K-best 검출 기법의 단점을 보완해 비트 오류 확률 성능을 개선하고 평균 연산량을 낮춘 적응 K-best 기법을 제안하였다.

Finite Element Analysis of Reinforced Concrete Shear Walls with a Crack under Cyclic Loading

  • Kato, S.;Ohya, M.;Shimaoka, S.;Takayama, M.
    • Computational Structural Engineering : An International Journal
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    • 제1권2호
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    • pp.107-116
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    • 2001
  • The present paper investigates the nonlinear behavior of reinforced concrete shear walls with a crank based on a finite element analysis. The loading type is a horizontal cyclic one such as earthquake loads. Experiments of the shear walls with and without cranks, performed previously to see flow the behavior changes depending on the crank, are compared with the results obtained from the finite element analysis. The finite element analysis is based on an isoparametric degenerated shell formulation. The nonlinear constitutive equations fur concrete are modeled adopting the formulation based on a concept of Ring Typed-Lattice Model. The experiments indicate that the shear walls with a crank have low stiffness and relatively low carrying capacity compared with an ordinary plane shear wall without cranks and that they are more ductile, and the tendency is a1so confirmed based on the finite element analysis. Moreover, a good agreement between the experiments and analyses is obtained, accordingly, it is confined that the present numerical analysis scheme based on the Lattice Model is a powerful one to evaluate the behavior of reinforced concrete shear walls with cranks and without cranks.

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격자형 용접선 추적을 위한 용접 이동로봇의 모델링 및 제어 (Modeling and Control of Welding Mobile Robot for the Tracking of Lattice Type Welding Seam)

  • 이근유;서진호;오명석;김상봉
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.923-928
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    • 2003
  • This paper presents the motion control of a mobile robot with arc sensor for lattice type welding. Its dynamic equation and motion control method for welding speed and seam tracking are described. The motion control is realized in the view of keeping constant welding speed and precise target line even though the robot is driven along a straight line or comer. The mobile robot is modeled based on Lagrange equation under nonholonomic constraints and the model is represented in state space form. The motion control of the mobile robot is separated into three driving motions of straight locomotion, turning locomotion and torch slider controls. For the torch slider control, the proportional integral derivative (PID) control method is used. For the straight locomotion, a concept of decoupling method between input and output is adopted and for the turning locomotion, the turning speed is controlled according to the angular velocity value at each point of the comer with range of $90^{\circ}$ constrained to the welding speed. The proposed control methods are proved through simulation results and the results have proved that the mobile robot has enough ability to apply the lattice type welding line.

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Modeling and Motion Control of Mobile Robot for Lattice Type Welding

  • Jeon, Yang-Bae;Kim, Sang-Bong
    • Journal of Mechanical Science and Technology
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    • 제16권1호
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    • pp.83-93
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    • 2002
  • This paper presents a motion control method and its simulation results of a mobile robot for a lattice type welding. Its dynamic equation and motion control methods for welding speed and seam tracking are described. The motion control is realized in the view of keeping constant welding speed and precise target line even though the robot is driven for following straight line or curve. The mobile robot is modeled based on Lagrange equation under nonholonomic constraints and the model is represented in state space form. The motion control of the mobile robot is separated into three driving motions of straight locomotion, turning locomotion and torch slider control. For the torch slider control, the proportional-integral-derivative (PID) control method is used. For the straight locomotion, a concept of decoupling method between input and output is adopted and for the turning locomotion, the turning speed is controlled according to the angular velocity value at each point of the corner with range of 90$^{\circ}$ constrained to the welding speed. The proposed control methods are proved through simulation results and these results have proved that the mobile robot has enough ability to apply the lattice type welding line.

FDTD 시뮬레이션을 이용한 육방정계형 2차원 광자결정에서의 광자밴드갭 특성 정규화 (Normalized characteristics of the photonic bandgaps in two-dimensional photonic crystals with a hexagonal lattice by FDID simulation)

  • 여종빈;이현용
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 하계학술대회 논문집
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    • pp.38-38
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    • 2009
  • Characteristics of the photonic bandgaps (PBGs) in two-dimensional photonic crystals (2D PCs) with a hexagonal lattice have theoretically studied using a finite difference time domain (FDTD) simulation. In this research, we propose a concept of optical coverage ratio (OCR) as a new structural parameter to determine the PBGs for E-polarized light. The OCR is an optically compensated filling factor. It is possible to normalize the PBGs of 2D PCs by introducing the OCR.

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고분자 액체에 대한 새로운 상태방정식 (A New Equation of State for Polymeric Liquids)

  • 정해영
    • 대한화학회지
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    • 제44권6호
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    • pp.587-591
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    • 2000
  • 고분자액체의 상태방정식을 구하기 위하여 많은 이론들이 제안되어 왔다. 이론들의 대부분은 cell, hole, free volume 또는 lattice 등의 개념에 근거를 두고 있다. 가장 성공적인 이론중의 하나로 평가받고 있는 것이 free volume의 개념을 근거로 한 Flory의 상태방정식 이론이다. 본 연구에서는 Flory 이론에서 사용한 van der Waals 포텐셜을 수정하여 새로운 상태방정식을 만들었다. 계산결과 새로운 상태방정식은 Flory 이론보다 PVT 실험값과 더 잘 일치함을 알 수 있었다.

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