• Title/Summary/Keyword: Axial Map

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Integrated Ground-Underground Spatial Network for Urban Spatial Analysis (도시 공간분석을 위한 지상·지하 공간 네트워크)

  • Piao, Gensong;Choi, Jaepil
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.34 no.4
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    • pp.69-76
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    • 2018
  • The purpose of this study is to propose and verify a spatial network construction method that integrated roads and subway lines to improve the predictability of the urban spatial analysis model. The existing axial map for urban spatial analysis did not reflect the subway line that serves as an important moving space in modern cities. To improve this axial map, proposed a Ground-Underground Spatial Network by integrating the underground spatial network with the axial map. As a result of the integration analysis, the Ground-Underground Spatial Network(GUSN) were similar to the movement frequency. Correlation of GUSN was 0.723, which showed higher explanatory power than correlation coefficient of 0.575 in axial map. The result of this study is expected to be a theoretical basis for constructing spatial network in urban space analysis with subway.

Axial map Implementation Using Linear Generalization of GIS data (GIS 도로 데이터의 일반화를 이용한 Axial map 구현 방법에 관한 연구)

  • Kwon, Soon-Il;Park, Soo-Hong;Joo, Yong-Jin
    • Spatial Information Research
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    • v.18 no.4
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    • pp.99-108
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    • 2010
  • Space Syntax methodology can be quantitatively calculated spatial cognitive analysis by number of turns_ In the existing GIS-based spatial information service provide 'physical distance' due to the shortest distance as a priority. but pedestrians tends to choose the path with concerned a lot of emphasis of safety, more vitality way from the crime at night, traffic accidents, and comfort on a road. Human's 'psychological distance' may reflect the spatial information services and provided path should be. In this study, using GIS Road Data implements the axial map with idea of the linear simplification principles. Traditional axial map of the Space Syntax get the assumption from the actual traffic values by comparing the results of correlation relationship. Through these methods, the actual relationship between traffic and test values have the correlation value($R^2$= 0.5387) 50% level and was able to get the results.

Higher Order Shimming for Ultra-fast Spiral-Scan Imaging at 3 Tesla MRI System (3 Tesla MRI 시스템에서 초고속 나선주사영상을 위한 고차 shimming)

  • Kim, P.K.;Lim, J.W.;Ahn, C.B.
    • Investigative Magnetic Resonance Imaging
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    • v.11 no.2
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    • pp.95-102
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    • 2007
  • Purpose: To acquire high-resolution spiral-scan images at higher magnetic field, high homogeneous magnetic field is needed. Field inhomogeneity mapping and in-vivo shimming are important for rapid imaging such as spiral-scan imaging. The rapid scanning sequences are very susceptible to inhomogeneity. In this paper, we proposed a higher-order shimming method to obtain homogeneous magnetic field. Materials and Methods: To reduce measurement time for field inhomogeneity mapping, simultaneous axial/ sagittal, and coronal acquisitions are done using multi-slice based Fast Spin echo sequence. Acquired field inhomogeneity map is analyzed using the spherical harmonic functions, and shim currents are obtained by the multiplication of the pseudo-inverse of the field pattern with the inhomogeneity map. Results: Since the field inhomogeneity is increasing in proportion to the magnetic field, higher order shimming to reduce the inhomogeneity becomes more important in high field imaging. The shimming technique in which axial, sagittal, and coronal section inhomogeneity maps are obtained in one scan is developed, and the shimming method based on the analysis of spherical harmonics of the imhomogenity map is applied. The proposed technique is applicable to a localized shimming as well. High resolution spiral-scan imaging was successfully obtained with the proposed higher order shimming. Conclusion: Proposed pulse sequence for rapid measurement of inhomogeneity map and higher order shimming based on the inhomogeneity map work very well at 3 Tesla MRI system. With the proposed higher order shimming and localized higher order shimming techniques, high resolution spiral-scan images are successfully obtained at 3 T MRI system.

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Use of similarity indexes to identify spatial correlations of sodium void reactivity coefficients

  • Jimenez-Carrascosa, Antonio;Garcia-Herranz, Nuria
    • Nuclear Engineering and Technology
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    • v.52 no.11
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    • pp.2442-2451
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    • 2020
  • The safety level of Sodium Fast Reactors is directly related with the sodium void reactivity. A low-void effect design has been proposed within the Horizon2020 ESFR-SMART project thanks to the introduction of a sodium plenum above the active core. In order to assess the impact of this core conception on transient analysis, a map with the spatial distribution of sodium void worth can be computed and fed into a point-kinetics-based transient code. Due to the spatial correlations between neighboring zones, the global effect of voiding two different axial or radial regions is not necessarily the sum of both individual contributions. Neglecting those correlations in the void worth map and consequently in the transient analysis may lead to an unrealistic prediction of the transient sequences. In this work, a method based on sensitivity analysis and similarity assessment is proposed for predicting those correlations. The method proved to be able to establish correlations between axial slices of a sub-assembly and was checked against realistic sodium void propagation patterns.

SURFACE PHOTOMETRY OF BARRED GALAXIES.: I. MORPHOLOGY

  • Ann, Hong-Bae
    • Journal of The Korean Astronomical Society
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    • v.19 no.2
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    • pp.69-89
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    • 1986
  • The global morphology and geometric parameters of 39 barred galaxies are investigated, by using isophote map and isodensity tracings obtained from detailed surface photometry with the Kiso V-band plates. The observed results are as follows: i) There is no strong indication that the ratio of bar length to disk size is correlated with Hubble type, except that the largest bars appear in the SBb galaxies. ii) The mean value of axial ratios of bars is $2.0{\pm}0.4$ and there is a trend that early type galaxies have smaller axial ratios than late type galaxies. iii) About 15% of early type barred galaxies(Sb0-SBb) have triaxial bulges.

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An Analysis on The Visual Configuration of an Exhibition Space in Art Museum - Focusing on an Exhibition space Room-to-room - (미술관 전시공간의 시각구조 분석 - 개실형 전시공간의 분석을 중심으로 -)

  • Lee, Jong-Sook;Lim, Che-Zinn
    • Korean Institute of Interior Design Journal
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    • v.16 no.6
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    • pp.197-204
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    • 2007
  • In the spatial configuration of room-to-room art museums, openings and walls are important physical factors, and openings are a medium for connecting spaces. Also, by spatially composing walls and openings, spaces can be connected visually and physically, and movements and directions may vary depending on the location or size of walls and openings. In this study, 5 museums are investigated: Sainsbury Wing in London, Gemaldegalerie In Berlin, Alte Pinakotkek in Munich, Neue Pinakothek in Munich, and Staatsgalerie Stuttgart in Stuttgart. Using DepthMap program, the characteristics of visual-spatial composition of each museum are derived by comparing the Connectivity, Visual integration, and Isovist maximum radial. From an analysis of spatial distribution, a relationship with visibility is investigated. The results of this study showed that the combination of visual axial lines affect the spatial configuration of the room-to-room museums. Depending on the location of opening, the museums can be classified as follows: 1) Museums with the 1st visual axial line and the 2nd and 3rd auxiliary visual axial lines ; 2) museums with several equal visual axial lines; and 3) museums with only center axial line.

Aerodynamic Performance Prediction of Multistage Axial-Flow Compressors with Its Applications (다단축류압축기의 공력성능 예측기법 개발 및 적용연구)

  • Chung, H.T.;Park, C.H.
    • Journal of Power System Engineering
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    • v.3 no.3
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    • pp.54-59
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    • 1999
  • The purpose of the present study was to develop the numerical method for predicting the on-design and off-design performance of multistage axial-flow compressors. The aerodynamic properties in blade rows were analyzed by incorporating the streamline curvature method as a quasi 3D analysis with the imperical modeling of exit flow angle and loss coefficients. The present calculation procedure has been tested by applying to 5-stage compressors and good agreement with experiments has been found. The detail analysis of aerodynamic performances has been done on the compression part of the bench-scaled gas turbine engines. The predicted performance map at the variable speedline and flow rates could be used as a guide of the engine operation.

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Study on Error Reduction in Dual Wavelength Digital Holography Using Modified Fine Map (수정된 화인 맵을 이용한 2-파장 홀로그래피와 잡음 제거 연구)

  • Yu, Young-Hun
    • Korean Journal of Optics and Photonics
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    • v.22 no.3
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    • pp.129-133
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    • 2011
  • Dual-wavelength holography has better axial range than single-wavelength holography, allowing unambiguous phase imaging but at the expense of increased noise. We have studied error reduction in dual wavelength holography using a modified fine map. The fine map is successful in measurement and has shown error reduction when the height of the object is less than the appled wavelength, but is unstable when the step height is larger than that wavelength. We have modified the fine map and we have found that the modified fine map was successful in measurement and error reduction even though the height of object was larger than the wavelength.

Design Strategies for Multi-Stage Axial Turbines (다단 축류터빈 공력설계 및 공력성능 향상기법)

  • Kang, Young-Seok;Rhee, DongHo;Cha, BongJun;Yang, SooSeok
    • The KSFM Journal of Fluid Machinery
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    • v.17 no.5
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    • pp.78-82
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    • 2014
  • This paper describes a brief aerodynamic design procedure of multi-stage axial turbine. The design procedure was established including one dimensional scratch design, through flow analysis with empirical correlations, two dimensional airfoil design and three dimensional airfoil stacking. Detailed aerodynamic performance assessment was done with full three dimensional CFD method at the design and off design conditions to construct turbine performance map. With the present method, aerodynamic design procedure of 1st and 2nd stages of high pressure turbine for 10,000lbf class turbofan engine was introduced.

The Prediction of the Axial Flow Fan Noise by Using Through-Flow Analysis Method (관통유동 해석 방법을 이용한 축류형 홴의 소음예측)

  • Lee, Chan;Chung, Dong-Gyu;Hong, Soon-Seong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.371-379
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    • 2000
  • A noise prediction method of axial flow fan is developed by incorporating through-flow method and vortex shedding noise model. Fan noise is assumed to be generated due to the pressure fluctuation induced by wake vortices of fan blades and radiate as diploe distribution. The wake vortices are analyzed by combining Karman vortex street model and through-flow analysis results, and the vortex-induced fluctuating pressure on blade surface is calculated by thin airfoil theory. The predicted sound pressure levels and directivity patterns of fan noise by the present method are favorably compared with fan noise test data. Furthermore, the present method is shown to be very useful for predicting the aero-acoustic performance map of the fan operated at off-design point.

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