• 제목/요약/키워드: Cross effects

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시위 방향 비대칭 단면의 복합재료 박벽보의 동특성 연구: I. 단일-셀 (Dynamic Characteristics of Composite Thin-Walled Beams with a Chord wise Asymmetric Cross-Section: I. Single-Cell)

  • 김근택
    • 항공우주시스템공학회지
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    • 제12권6호
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    • pp.41-49
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    • 2018
  • 이번 연구에서는 복합재료 박벽보(thin-walled beam)에서 시위 방향으로 단일 셀의 비대칭성 단면을 가지는 모델을 선정하여, 단면의 형상에 대한 이론적인 동특성을 연구하였다. 이를 위해 전단 변형 효과(transverse shear effect)와 와핑 구속 효과(warping restraint effect), 보의 길이 방향으로 일정한 테이퍼비와 기하학적 단면비 등을 고려하고, 비대칭 단면의 와핑 함수 보정을 통해 수학적 모델링을 수행하였다. 그 결과에 따라, 고려한 단면의 질량 계수와 강성 계수 및 고유 진동수 등의 특성을 조사하였다. 특히, 단면의 비대칭성, 와핑 함수를 보정하지 않은 경우, 모델의 테이퍼비와 단면비 등이 고유 진동수에 미치는 영향을 비교 분석하였다.

Analysis of cross-talk effects in volume holographic interconnections using perturbative integral expansion method

  • Jin, Sang-Kyu
    • Journal of the Optical Society of Korea
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    • 제2권2호
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    • pp.58-63
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    • 1998
  • Cross-talk effects in high-density volume holographic interconnections are investigated using perturbative iteration method of the integral form of Maxwell's wave equation. In this method, the paraxial approximation and negligence of backward scattering introduced in conventional coupled mode theory is not assumed. Interaction geometries consisting of non-coplanar light waves and multiple index gratings are studied. Arbitrary light polarization is considered. Systematic analysis of cross-talk effects due to multiple index gratings is performed in increasing level of diffraction orders corresponding to successive iterations. Some numerical examples are given for first and third order diffraction.

R&D프로젝트군의 효과추정을 위한 복합효과 평가시스템의 설계 (A Design of Cross Effect Evaluation System for Estimating the Effectiveness of R&D Projects)

  • 강일중;권철신;박준호
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회 2003년도 추계학술대회 및 정기총회
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    • pp.21-24
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    • 2003
  • $\ulcorner$Cost Effectiveness Analysis$\lrcorner$ has been widely used to evaluate the effectiveness of R&D resources. But, almost of cost effectiveness evaluation systems have some problems, especially the cross effect among R&D projects has not been considered. To solve this problem, we have designed a new $\ulcorner$Cross Effect Evaluation System(CEES)$\lrcorner$, which are able to estimate multi-effects and cross effects by completion time among several projects.

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Analysis of rotational end restraint for cross-beams of railway through truss bridges

  • Siekierski, Wojciech
    • Steel and Composite Structures
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    • 제35권1호
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    • pp.29-41
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    • 2020
  • Cross-beams of modern through truss bridges are connected to truss chord at its nodes and between them. It results in variable rotational end restraint for cross-beams, thus variable bending moment distribution. This feature is captured in three-dimensional modelling of through truss bridge structure. However, for preliminary design or rapid assessment of service load effects such technique of analysis may not be available. So an analytical method of assessment of rotational end restraint for cross-beam of through truss bridges was worked out. Two cases - nodal cross-beam and inter-nodal cross-beam - were analyzed. Flexural and torsional stiffness of truss members, flexural stiffness of deck members and axial stiffness of wind bracing members in the vicinity of the analyzed cross-beam were taken into account. The provision for reduced stiffness of the X-type wind bracing was made. Finally, general formula for assessment of rotational end restraint was given. Rotational end restraints for cross-beams of three railway through truss bridges were assessed basing on the analytical method and the finite element method (three-dimensional beam-element modelling). Results of both methods show good agreement. The analytical method is able to reflect effects of some structural irregularities. On the basis of the obtained results the general values of rotational end restraint for nodal and inter-nodal cross-beams of railway through truss bridges were suggested.

Effects of Cross-Head Speed And Probe Diameter on Instrumental Measurement of Tomato Firmness

  • Batu, Ali;Thompson, A.Keith
    • 한국농업기계학회:학술대회논문집
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    • 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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    • pp.1340-1345
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    • 1993
  • Five textural characteristics , epicarp strength, deformation , firmness , toughness and penetration time were calculated from force/deformation curves obtained by pressure testing tomato fruits. The fruits were harvested at either the mature-green or red maturity stages. The effects of changing the probe diameter and cross-head speed were investigated on force/deformation characteristics of tomatoes. It was confirmed that increasing of cross-head speed and probe diameter highly significantly effect all textural of the characteristics mentioned above , except epiarp strength of red tomatoes at 200 mm minute cross-head and penetration time of red and green tomatoes after 200mm minute and 100 mm minute cross-head respectively.

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브레이크 디스크 로터 표면 수직 구멍의 영향에 관한 연구 (A Study on the Cross-drilling Effects of Brake Disc Rotor)

  • 서영진;오제하;이준상;강경수;정근성
    • 한국자동차공학회논문집
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    • 제16권1호
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    • pp.100-105
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    • 2008
  • Cross-drilling on the brake disc is generally known as a way of improving cooling efficiency. In other theories, cross-drilled holes act like a path of gas or water and are also known that they can reduce fading and wetting of brake rotors. However, in disc rotors with cross-drilling, thermal crack phenomena have been reported more frequently and more manufacturing cost should be paid than non cross-drilled disc rotors. In this study, to examine various effects of cross-drilling on the brake disc, two kinds of brake disc rotors, cross-drilled and non cross-drilled, were used in computational fluid dynamic analyses and dynamometer tests.

Mixed-effects LS-SVR for longitudinal dat

  • Cho, Dae-Hyeon
    • Journal of the Korean Data and Information Science Society
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    • 제21권2호
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    • pp.363-369
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    • 2010
  • In this paper we propose a mixed-effects least squares support vector regression (LS-SVR) for longitudinal data. We add a random-effect term in the optimization function of LS-SVR to take random effects into LS-SVR for analyzing longitudinal data. We also present the model selection method that employs generalized cross validation function for choosing the hyper-parameters which affect the performance of the mixed-effects LS-SVR. A simulated example is provided to indicate the usefulness of mixed-effect method for analyzing longitudinal data.

일반 사각 단면 형상을 갖는 박판보의 끝단효과에 관한 연구 (End Effects of Thin-Walled Beams with General Quadrilateral Cross Sections)

  • 김진홍;김윤영
    • 대한기계학회논문집A
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    • 제24권9호
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    • pp.2191-2201
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    • 2000
  • End effects due to sectional deformations of thin-walled beams with closed cross section are analysed by a one-dimensional theory. In particular, end effects associated with warping (out of plane m otion) and distortion (in plane motion) are investigated. The exact solutions as a vector form are newly derived to reveal slowly-decaying nature of the end effects in a thin-walled beam loaded by a couple. Several examples of thin-walled beams under various loading conditions indicate that the local end effect zone due to warping and distortion is approximately ten times the typical beam width.

Cross Correlated Effects of Radiation Damping and the Distant Dipolar Field with a Pulsed Field Gradient in Solution NMR

  • Chung Kee-Choo;Ahn Sang-Doo
    • 한국자기공명학회논문지
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    • 제10권1호
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    • pp.46-58
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    • 2006
  • With a simple pulse sequence ($\pi/2$-{gradient, duration T}-acquisition) in solution NMR, detected signal has slowly grown up to percents of the equilibrium magnetization. The source of this unusual resurrection of dephased magnetization after a crushed gradient is cross-correlated effects of radiation damping and the distant dipolar field, which has been demonstrated by a numerical simulation and theoretical analysis.

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