• Title/Summary/Keyword: Geometrical relationship

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GEOMETRICAL IMPLICATION OF THE CME EARTHWARD DIRECTION PARAMETER AND ITS COMPARISON WITH CONE MODEL PARAMETERS

  • Moon, Y.J.;Kim, R.S.;Cho, K.S.
    • 천문학회지
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    • 제42권2호
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    • pp.27-32
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    • 2009
  • Recently, we suggested a CME earthward direction parameter as an important geoeffective parameter that has been demonstrated by front-side halo CME data. In this study, we present the geometrical implication of this parameter by comparing with the parameters from a CME cone model. Major results from this study can be summarized as follows. First, we derive an analytic relationship between the cone model parameters(the half angular width of a cone and the angle between the cone axis and the plane of sky) and the earthward direction parameter. Second, we demonstrate a close relationship between the earthward direction parameter and the cone axis angle using 32 front-side full halo CMEs. Third, we found that there is noticeable inconsistency between the cone axis angles estimated from the cone model fitting to the CMEs and from their associated flare positions, implying that the flare position should not be considered as a good earthward direction parameter. Finally we present several advantages of our earthward direction parameter in terms of the forecast of a geomagnetic storm based on CME parameters.

Prediction of Thermal Decomposition Temperature of Polymers Using QSPR Methods

  • Ajloo, Davood;Sharifian, Ali;Behniafar, Hossein
    • Bulletin of the Korean Chemical Society
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    • 제29권10호
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    • pp.2009-2016
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    • 2008
  • The relationship between thermal decomposition temperature and structure of a new data set of eighty monomers of different polymers were studied by multiple linear regression (MLR). The stepwise method was used in order to variable selection. The best descriptors were selected from over 1400 descriptors including; topological, geometrical, electronic and hybrid descriptors. The effect of number of descriptors on the correlation coefficient (R) and F-ratio were considered. Two models were suggested, one model having four descriptors ($R^2$ = 0.894, $Q^2_{cv}$ = 0.900, F = 172.1) and other model involving 13 descriptors ($R^2$ = 0.956, $Q^2_{cv}$ = 0.956, F = 125.4).

대면적 FPD 글래스 수직 이송용 클린 비접촉식 컨베이어 구동부 설계 및 해석 (Design and Analysis of a Clean Non-contact type Conveyor's Driving Mechanism for Vertical Transfer of FPD Glass)

  • 심재홍
    • 반도체디스플레이기술학회지
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    • 제8권4호
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    • pp.71-76
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    • 2009
  • The clean non-contact type conveyor system for vertical transfer of large size FPD(Flat Panel Display) glasses has been installed at FPD production line just since a few years ago. The most important part of the conveyor is the 3 axis permanent magnet rollers faced orthogonally in pairs. However, the systematic design method about it has not been proposed yet. In this paper, we studied a design analysis for determining geometrical parameters of the magnetic roller by using a commercial FEM tool of the 3D Maxwell. Through a series of simulation, we obtained the relationship of several geometrical parameters affecting the torque of the conveyor.

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1-알콕시-4-니트로아닐린들의 糖度에 關한 硏究 (Sweet Taste Mechanism of 1-Alkoxy-4-nitroaniline)

  • 김의락;전무식;채영복
    • 대한화학회지
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    • 제17권6호
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    • pp.391-394
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    • 1973
  • 반실험적인 양자역학 이론인 extended Huckel theory를 nitroaniline, 1-methoxy-4-nitroaniline과 1-ethoxy-4-nitroaniline에 적용하여 정량적으로 변화하는 sweetness기구를 구명코져 nitroaniline을 coplanar로 두고 ortho치환체의 geometrical rotation을 시켰을 때 charge density와 sweetness와의 상관관계를 설명하였다.

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기기 기초 시스템의 지렛대 효과 해석 (The Analysis of Prying Action for Equipment Anchor System.)

  • 김강식;유원진;김갑순;서용표
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2002년도 봄 학술발표회 논문집
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    • pp.83-90
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    • 2002
  • Prying action caused by the eccentric loads within the equipment itself and the anchors can result in a lack of adequate stiffness and strength within the equipment and in additional moment loadings on the anchors. A typical case of prying action often found in power plants is the angle type anchorage system with expansion bolt. Experimental and analytical studies were performed to investigate the relationship between the amplification factors and various geometrical and material factors. It is revealed that the value of the factor is effected by the stiffness of bolt and angle, lateral stiffness of cabinet, and geometrical parameter of anchor system.

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Ab initio Studies on the Hetero Diels-Alder Cycloaddition

  • 이본수;김찬경;최정욱;이익준
    • Bulletin of the Korean Chemical Society
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    • 제17권9호
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    • pp.849-853
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    • 1996
  • Hetero Dieis-Alder reactions containing phosphorus atom at various positions of diene and dienophile as well as standard Dieis-Alder reaction between ethylene and cis-l,3-butadiene have been studied using ab initio method. Activation energy showed a good linear relationship with the FMO energy gap between diene and dienophile, which can be normally used to explain Dieis-Alder reactivity. Since π-bond cleavage and σ-bonds formation occur concertedly at the TS, geometrical distortion of diene and dienophile from the reactant to the transition state is the source of barrier. Based on the linear correlations between activation barrier and deformation energy, and between deformation energy and π-bond order change, it was concluded that the activation barrier arises mainly from the breakage of π-bonds in diene and dienophile. Stabilization due to favorable orbital interaction is relatively small. The geometrical distortions raise MO levels of the TS, which is the origin of the activation energy. The lower barrier for the reactions of phosphorus containing dienophile (reactions C, D, and E) can be explained by the electronegativity effect of the phosphorus atom.

제임스 터렐의 작품에 나타난 기하학적 공간구성, 시지각적 역동성 그리고 존재론적 의미에 관한 연구 - '웨지워크', '스페이스 디비전', '스카이스페이스' 프로젝트를 중심으로 - (A Study on the Geometrical Space Composition, Dynamic Visual Perception and Questions of Existence found in the Works of James Turrell - Focusing on 'Wedgework', 'Space Division', 'Skyspace' Projects -)

  • 김종진
    • 한국실내디자인학회논문집
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    • 제21권5호
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    • pp.145-152
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    • 2012
  • Since 1966 when James Turrell completed his studies on Art, he has been working on the consistent theme of Art. For the 46 years of time, site contexts, scales, methods of light have been changed and they made Turrell's unique 'project series'. Each series has different spatial, visual-perceptual forms and characteristics from other series. The differences were caused by the given situations, but also Turrell intentionally pursued it. However, there are essential theme of art that has not changed in most of Turrell's projects. Target of this paper is to study the unchanged theme as well as the differences. The study starts with three questions: first, what is the geometrical space composition?, second, what is the visual-perceptual phenomenon?, third, what is the hidden consistent theme? This research focuses on three case projects: Wedgework, Space Division Constructions, Skyspaces. These project series are in between the early small object-like installations and the late mega-scale outdoor projects. The study found that geometrical space composition has important role to give visual-perceptual dynamism to the viewer. The phenomenological perception is connected to the questions of relationship between human and space, ultimately human and the world. Although the Merleau-Ponty's philosophy has been related to the work of Turrell in various previous studies, Cartesian 3-dimensional geometry has also crucial role to experiment a viewer's perceptual boundaries. Image of infinity is another aspect of three cases, especially Space Division Constructions and Skyspaces. Through these structure, Turrell's work lead to an ultimate question of meaning for human existence in infinite space. It is hoped that this paper is helpful for Architecture and Interior design field in which light and space are essential.

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요트 설계시 선형의 기하학적 특성과 성능 사이의 관련성에 관한 연구 (A Study on the Relation between Hull Geometric Characteristics and Performance in the Yacht Design)

  • 하득기;김수영;김용재
    • 한국해양공학회지
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    • 제17권6호
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    • pp.91-95
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    • 2003
  • Yacht design is significantly affected by the hull geometrical characteristics. Therefore, it is necessary to closely examine the relation between hull and performance, before considering characteristics of sea condition. In this study, Genetic Programming is used to derive a formula the relationship between hull geometric characteristics and performance. Using the formula, a new guideline is proposed to determine performance of a yacht.

마할라노비스 거리와 기하학적 파라메터에 의한 표적의 인식 (Target Identification using the Mahalanobis Distance and Geometric Parameters)

  • 이준웅;권인소
    • 제어로봇시스템학회논문지
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    • 제5권7호
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    • pp.814-820
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    • 1999
  • We propose a target identification algorithm for visual tracking. Target identification is realized by finding out corresponding line segments to the hypothesized model segments of the target. The key idea is the combination of the Mahalanobis distance with the geometrical relationship between model segments and extracted line segments.

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웨어러블 시스템에서 눈동자의 움직임을 이용한 인터페이스 (Eye Gaze Interface in Wearable System)

  • 권기문;이정준;박강령;김재희
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
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    • pp.2124-2127
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    • 2003
  • This paper suggests user interface method with wearable computer by means of detecting gaze under HMD, head mounted display, environment. System is derived as follows; firstly, calibrate a camera in HMD, which determines geometrical relationship between monitor and captured image. Second, detect the center of pupil using ellipse fitting algorithm and represent a gazing position on the computer screen. If user blinks or stares at a certain position for a while, message is sent to wearable computer. Experimental results show ellipse fitting is robust against glint effects, and detecting error was 6.5%, and 4.25% in vertical and horizontal direction, respectively.

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