• Title/Summary/Keyword: space plane

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New Instabilities in Accretion Flows onto Black Holes

  • MOLTENI D.;FAUCI F.;GERARDI G.;BISIKALO D.;KUZNETSOV O.;ACHARYA K.;CHAKRABARTI S.
    • Journal of The Korean Astronomical Society
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    • v.34 no.4
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    • pp.247-249
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    • 2001
  • The accretion disks are usually supposed symmetric to reflection on the Z=0 plane. Asymmetries in the flow are be ver-y small in the vicinity of the compact accretor. However their existence can have a important role in the case of subkeplerian accretion flows onto black holes. These flows lead to strong heating and even to the formation of shocks close to the centrifugal barrier. Large asymmetries are due to the development of the KH instability triggered by the small turbulences at the layer separating the incoming flow from the out coming shocked flow. The consequence of this phenomenon is the production of asymmetric outflows of matter and quasi periodic oscillations of the inner disk regions up and down the Z=0 plane.

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An Optimality Criteria applied to The Plane Frames (평면 뼈대 구조물에 적용된 최적규준)

  • 정영식;김창규
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1995.10a
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    • pp.17-24
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    • 1995
  • This work proposes an optimality criteria applicable to the optimum design of plane frames. Stress constraints as well as displacement constraints are treated as behavioural constraints and thus the first order approximation of stress constraints is adopted. The design space of practical reinforced concrete frames with discrete design variables has been found to have many local minima, and thus it is desirable to find in advance the mathematical minimum, hopefully global, prior to starting to search a practical optimum design. By using the mathematical minimum as a trial design of any search algorithm, we may not full into a local minimum but apparently costly design. Therefore this work aims at establishing a mathematically rigorous method ⑴ by adopting first-order approximation of constraints, ⑵ by reducing the design space whenever minimum size restrictions become "active" and ⑶ by the of Newton-Raphson Method.

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A Study on the Conception of Planarity in Modern Art (근대 건축에서의 '평면성' 개념)

  • Lee, Kwang-In
    • Journal of The Korean Digital Architecture Interior Association
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    • v.7 no.2
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    • pp.59-65
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    • 2007
  • This study is aimed to find out the conception of planarity in Modern Architecture. Some architecture historians such as Hildebrand and Schmarsow indicated the planarity by which new idea of space in architecture was made. The characteristics of the planar was embodied and developed through the proclamation of the ideology and their works in the avant-garde art movement of Cubism and Neoplasticism. The planarity in modern architecture was embodied from various aspects -the perception of space, the pictorial art and the metaphysics- by means of imaginary plane, superposition of planes, oscillation of plane, deconstruction of mass and elimination of natural color.

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Reflection and refraction of magneto-thermoelastic plane wave at the pre-stressed liquid-solid interface in generalized thermoelasticity under three theories

  • Kakar, Rajneesh;Kakar, Shikha
    • Earthquakes and Structures
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    • v.9 no.3
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    • pp.577-601
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    • 2015
  • The thermomagnetic effect on plane wave propagation at the liquid-solid interface with nonclassical thermoelasticity is investigated. It is assumed that liquid-solid half-space is under initial stress. Numerical computations are performed for the developed amplitude ratios of P, SV and thermal waves under Cattaneo-Lord-Shulman theory, Green-Lindsay theory and classical thermoelasticity. The system of developed equations is solved by the application of the MATLAB software at different angles of incidence for Green and Lindsay model. The effect of initial stress and magnetic field in the lower half-space are discussed and comparison is made in LS, GL and CT models of thermoelasticity. In the absence of magnetic field, the obtained results are in agreement with the same results obtained by the relevant authors. This study would be useful for magneto-thermoelastic acoustic device field.

Off-axis pSDF Spatial Matched Filter for Pattern Classification (패턴분류를 위한 Off-axis pSDF 공간정합필터)

  • 임종태;박한규;김명수;김성일
    • Korean Journal of Optics and Photonics
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    • v.2 no.2
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    • pp.83-88
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    • 1991
  • Studies on space-invariant pattern recognition have been carried out from various approaches. Pattern recognition system using SDF filter, from weighted linear summation of tranining images, has been the focus of research since its first appearence. In this thesis, off-axis pSDF spatial matched filter has been constructed by combining angular multiplexing of off-axis reference plane wave with pSDF filter made from pseudo-inverse algorithm, and transformed to phase only filter. From observation of the correlation responses in the correlation plane, it is shown that proposed off-axis pSDF spatial matched filter is available to pattern classification and can be used for optical correlator.

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An Interactive Method for Multicriteria Simulation Optimization with Integer Variables (이산형 다기준 시뮬레이션 최적화를 위한 대화형 방법)

  • Shin, Wan-S.;Kim, Jae-Yong
    • Journal of Korean Institute of Industrial Engineers
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    • v.22 no.4
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    • pp.633-649
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    • 1996
  • An interactive multicriteria method, which is called the Modified Pairwise Comparison Stochastic Cutting Plane (MPCSCP) method, is proposed for determining the best levels of the integer decision variables needed to optimize a stochastic computer simulation with multiple response functions. MPCSCP combines good features from interactive tradeoff cutting plane methods and response surface methodologies. The proposed method uses a simple pairwise man-machine interaction and searches an integer space uniformly by using the experimental design which evaluates the decision space centering around an integer center point. The characteristics of the proposed method are investigated through an extensive computational study. The parameter configurations examined in the study are (1) variability of the sampling errors, (2) the size of experimental design, (3) the relaxation of cutting planes, and (4) the levels of decision maker's inconsistency.

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Effect of Three-dimensional Warping on Stiffness Constants of Closed Section Composite Beams

  • Dhadwal, Manoj Kumar;Jung, Sung Nam
    • International Journal of Aeronautical and Space Sciences
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    • v.18 no.3
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    • pp.467-473
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    • 2017
  • This paper focuses on the investigation of three-dimensional (3D) warping effect on the stiffness constants of composite beams with closed section profiles. A finite element (FE) cross-sectional analysis is developed based on the Reissner's multifield variational principle. The 3D in-plane and out-of-plane warping displacements, and sectional stresses are approximated as linear functions of generalized sectional stress resultants at the global level and as FE shape functions at the local sectional level. The classical elastic couplings are taken into account which include transverse shear and Poisson deformation effects. A generalized Timoshenko level $6{\times}6$ stiffness matrix is computed for closed section composite beams with and without warping. The effect of neglecting the 3D warping on stiffness constants is shown to be significant indicating large errors as high as 93.3%.

Estimation of a Gaze Point in 3D Coordinates using Human Head Pose (휴먼 헤드포즈 정보를 이용한 3차원 공간 내 응시점 추정)

  • Shin, Chae-Rim;Yun, Sang-Seok
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2021.10a
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    • pp.177-179
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    • 2021
  • This paper proposes a method of estimating location of a target point at which an interactive robot gazes in an indoor space. RGB images are extracted from low-cost web-cams, user head pose is obtained from the face detection (Openface) module, and geometric configurations are applied to estimate the user's gaze direction in the 3D space. The coordinates of the target point at which the user stares are finally measured through the correlation between the estimated gaze direction and the plane on the table plane.

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Identifying clusters of red supergiants in Galactic plane using 2MASS and GAIA G band colors

  • Lee, Jae-Joon;Chun, Sang Hyun
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.2
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    • pp.80.2-80.2
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    • 2021
  • Galactic young massive clusters are the ideal laboratories to study massive stellar evolution. Unfortunately, such objects are rare. Of particular interest are so-called Red Supergiant Clusters (RSGCs) that are currently only found toward the Scutum-Crux Galactic arm. Confirming their nature as RSGC is often not straight-fortward as distinguishing RSGs from AGB stars is still difficult even with high spectral resolution spectra. Here we report that broad band colors using 2MASS JHK and GAIA G band data can be useful in reducing the AGB contamination, thus providing selection criteria that effectively reveal the known RSGCs with negligible false positives. On the other hand, we suggest that RSGC4, one of the proposed RSGC candidates, may not be a cluster of RSGs as their colors are not compatible with our selection criteria. We discuss the nature of these stars together with our IGRINS spectroscopic observations. We also employ the same selection criteria to search for RSGC candidates in other parts of the plane, resulting in no prominent candidates.

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The Study on the Catholic Church's Liturgical Space in Pyeongtaek (평택지구 성당건축의 전례공간에 관한 연구)

  • Hwang Yong-Woon;Keum Yo-Chan
    • Journal of the Korean housing association
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    • v.16 no.2
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    • pp.27-35
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    • 2005
  • Liturgical space is the most important in the spaces of catholic church architecture. But Since 1980's, korea catholic church has concentrated on functionality, decoration and sensuous expression. Thus this study analyzed the catholic liturgical space for reinforcing the present status of catholic church through Pyeongtaek district's parish in Diocese of Suwon. Although there are many compositional elements in catholic liturgical space, this study focused on the figures of church plane, the arrangement of nave's chair, the condition of sanctuary and the place of sacristy etc. Though there are many changes in composition elements of liturgical space by the 2nd Council of the Vatican, composition elements of site(shape, price, access road, area etc.) have an effect on liturgical space, too. But up to now, despite the necessity of the principles of liturgical space which are yet to be lacked.