• Title/Summary/Keyword: Field configuration

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Development of Sag and Tension Sensitivity Estimation Method for Configuration Control under PPWS Erection in a Suspension Bridge (현수교 PPWS 가설중 형상관리를 위한 PPWS 새그 및 장력민감도 산정법 개발)

  • Jeong, Woon;Seo, Ju Won;Lee, Won Pyo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.5A
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    • pp.255-266
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    • 2012
  • Main cable of a suspension bridge is the important member which shows the overall structure integrity at bridge completion. Configuration of main cable is a free hanging state at cable erection completion and is different from that at bridge completion supporting the dead loads such as hanger, girder, and so on. Accordingly, the configuration control under cable erection is considerably significant because the configuration at cable erection completion has direct influence on that at bridge completion. That is performed by sag adjustments at center, side span and tension adjustments at anchor span. The former needs the sag sensitivity which represents the control quantity of strand length corresponding to that of sag. The latter requires the tension sensitivity which shows the change of strand tension according to that of strand temperature. In this study, the fundamental equations of cable were derived with the assumption of either catenary or parabola shape, the differential-related equations using chain rule on horizontal tension were drawn from those and finally the estimation methods of the sag / tension sensitivity were proposed from both those. The nonlinear numerical analysis flow charts of sag sensitivity based on the catenary equations were proposed and the sag sensitivities grounded on the differential-related equations were compared with the results using them for various parameters of sag change. Also, considering the combinations of sag change parameters, the calculation method of the final variation for the cable sag was suggested. For the real suspension bridge under construction with PPWS method, the sag/tension sensitivity were estimated considering the construction conditions like the change of PPWS length, PPWS temperature, bridge span, etc.. We hope that this study will be a systematic guideline for the configuration control under main cable erection and improved highly by field verification in the real bridge site.

Optical Pattern Switching in Semiconductor Microresonators as All-Optical Switch

  • Kheradmand, Reza;Dastmalchi, Babak
    • ETRI Journal
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    • v.31 no.5
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    • pp.593-597
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    • 2009
  • In this paper, we present a spatial perturbation method to control the optical patterns in semiconductor microresonators in the far-field configuration. We propose a fast all-optical switch which operates at a low light level. The switching beam controls the behavior of output beams with strong intensities. The method has been applied successfully to different optical patterns such as rolls, squares, and hexagons.

Study on Safety Consideration of ELF Magnetic Fields Emanating from Power Transmission Line for Electric Railways (전철용 성전선로에서 발생되는 극저주파 자기장의 안전성에 관한연구)

  • 임용배
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 1999.07a
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    • pp.156-164
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    • 1999
  • This paper shows that the configuration of power transmission lines currently in place is suitable on the basis of calculated magnetic field strengths. The magnetic fields were computed for typical current distributions on power transmission lines for electric railways, which are characterized by severe load fluctuations and phase distortions. The result of the numerical analysis are compared with th ELF guidelines of magnetic fields from several case studies. The final conclusion reached in that effects of the magnetic fields near power transmission lines for electric railways are not significant enough to cause a biological safety concern.

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ANCHOR MOORING LINE ANALYSIS IN COHESIVE SEAFLOOR

  • Sangchul Bang
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.03b
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    • pp.58-76
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    • 2000
  • An analytical solution method capable of determining the geometric configuration and developed tensile forces of mooring lines associated with fixed plate/pile or drag anchors is presented. The solution method, satisfying complete equilibrium conditions, is capable of analyzing multi-segmented mooring lines that can consist of either chains, cables, or wires embedded in layered seafloor soils. Centrifuge model tests and full -scale field tests were used to calibrate and validate the analytical solution.

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Incoherent Tomography for Conducting Cylinder by Using Single-Frequency Time-Harmonic Source (단일 주파수 시간조화 신호원을 사용한 도체기둥의 incoherent 단면영상법)

  • 강진섭;라정웅
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.35D no.1
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    • pp.1-7
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    • 1998
  • In this paper, an incoherent imaging of a conducting cylinder illuminated by the single-frequency time-harmonic plane wave is obtained via the back-projections of the intensity patterns of the forward total electric field scattered from this object in the circular rotational measurement configuration. The pheonmenon that interference fringes generated in the itesity patterns is removed in the back-projection process is interpreted numerically. This imaging method is validated by imagining conducting circular cylinders and the conditions to ge beter image are investigated.

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AERODYNAMIC ANALYSIS OF A PITCH OSCILLATING MID-SIZED AIRCRAFT (피치 진동하는 중형항공기의 공력 특성 해석)

  • Lee, Yung-Gyo;Kim, Cheol-Wan;Ahn, Seok-Min
    • Journal of computational fluids engineering
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    • v.16 no.1
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    • pp.48-52
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    • 2011
  • Aerodynamic analysis was done for a fuselage and wing configuration of a mid-sized aircraft using unsteady 3-dimensional Navier-Stokes solver. Various turbulent models including a transitional SST were used to observe a dynamic stall as well as cruise characteristics. Also, different mesh moving methods were evaluated. Flow hysteresis which causes dynamic stall was investigated through flow field investigations.

Preference Map using Weighted Regression

  • S.Y. Hwang;Jung, Su-Jin;Kim, Young-Won
    • Communications for Statistical Applications and Methods
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    • v.8 no.3
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    • pp.651-659
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    • 2001
  • Preference map is a widely used graphical method for the preference data set which is frequently encountered in the field of marketing research. This provides joint configuration usually in two dimensional space between "products" and their "attributes". Whereas the classical preference map adopts the ordinary least squares method in deriving map, the present article suggests the weighted least squares approach providing the better graphical display and interpretation compared to the classical one. Internet search engine data in Korea are analysed for illustration.

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Aerodynamic Design Techniques in The Launch Vehicle (발사체 개발에서의 공력설계 기법)

  • Ahn, Chang-Soo;Sun, Chul;Kang, Kyoung-Tai
    • 유체기계공업학회:학술대회논문집
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    • 2006.08a
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    • pp.41-44
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    • 2006
  • In the field of launch vehicle development, aerodynamic design means an overall management about external appearances. At least, related to outer figures of the launch vehicle, aerodynamic design has the initiative activities. For that reason, in this report, aerodynamic design techniques and application methods will be introduced.

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EIC integrated DCS with single console

  • Kawahara, Hiroshi;Hwa, Hong-Tae
    • 제어로봇시스템학회:학술대회논문집
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    • 1988.10b
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    • pp.928-933
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    • 1988
  • Control technology has been making remarkable progress in electrical control (E), instrumentation & control (I) and computer control (C) field respectively. In order to rationalize system engineering and simplify system configuration and operation work, so called, EIC are now to be integrated into one system. FUJI has developed it's own E, I&C integrated system, to meet above mentioned market requirements of variety. This paper describes basic concept of FUJI's Integrated Man-Machine Interface, hereinafter called SINGLE CONSOLE, from some view points of E, I, C integration technology.

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Quantitative Characterization of Solar Active Regions Based on Their Evolutionary Paths

  • Magara, Tetsuya
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.2
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    • pp.59.4-59.4
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    • 2017
  • We present a way of quantitatively characterizing solar active regions on the basis of their evolutionary paths. To determine characteristic properties of active regions with different sizes and configurations, we use a physics-based model to derive a relation between emerged magnetic flux and injected magnetic helicity (Flux-Helicity relation), the former of which gives scale information while the latter represents the magnetic field configuration of an active region. We demonstrate how this relation provides evolutionary paths of active regions and determines their characteristic properties, through a comparison with modeled active regions obtained from magnetohydrodynamic simulations.

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