• Title/Summary/Keyword: Source strength

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Analysis of a Panel Contribution of a Vehicle Compartment Using the Acoustic Reciprocal Theorem (음향 상호성 이론을 이용한 승용차 차실 판넬의 기여도 해석)

  • Kim, M.G.;Park, T.W.;Lee, S.H.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.2 no.2
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    • pp.59-72
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    • 1994
  • For a panel contribution of the passenger vehicle compartment, a model was created for acoustic analysis of the passenger vehicle compartment and through the acoustic normal modal analysis, frequencies and mode shapes of the resonance modes were calculated. Also, the contribution analysis of each panel was executed using acoustic reciprocal theorem, and through this analysis, normalized responses at the particular point indicate the relative contribution of each panel for generating noise and vibration

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Simulation of Flame-Vortex Interaction in Thin Laminar Flamelet Regime (얇은 층류 화염편 영역에서 화염과 와동의 산호 작용)

  • Kang, Ji-Hoon;Kwon, Se-Jin
    • 한국연소학회:학술대회논문집
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    • 1999.10a
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    • pp.47-54
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    • 1999
  • A method is developed to include the effect of volume expansion in the description of the flame dynamics using G-equation. Line volume-source is used to represent the effect of the exothermic process of combustion with source strength assigned by the density difference between the burned and the unburned region. The present model provides good agreement with the experimental results by using realistic volume expansion ratio which was not reached in the previous researches. Including volume expansion, the flow predicts the same behavior of measured velocity field qualitatively. The flame propagation in varying flow field due to volume expansion provides a promising way to represent the wrinkled turbulent premixed flames in a numerically efficient manner.

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Motion Analysis of a Very Large Floating Structure in Irregular Waves (불규칙파 중 초대형 부유식 해양 구조물에 대한 운동 해석)

  • 신현경;이호영;임춘규;신현수;박인규
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2000.04a
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    • pp.63-68
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    • 2000
  • A very large floating structure has rather small motion characteristics as to the whole body, while the motion at end part of such structure becomes largest due to the elastic motion of the structure. This paper presents on the theoretical result on the relative motion characteristics and green water phenomena of VLFS in waves This phenomena affect not only to strength of the structure but also the determination of depth of structure. To predict motion responses of structure in regular waves, the source-dipole distribution method and F.E.M is used By irregular wave results, the probability of occurrence of green water and response of the structure were calculated.

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proposals for enhancing the current HS-DSCH serving cell change procedure for UE mobility (향상된 HS-DSCH serving cell change procedure 제안)

  • Cheong, Young-Hoon
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.273-274
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    • 2008
  • According to current RRC procedures, network does not know either how long it will take the RRC reconfiguration message (such as Physical Channel Reconfiguration (PCR)/Transport Channel Reconfiguration (TCR)/Radio Bearer Reconfiguration (RBR)) to be transmitted over the source cell or how long the UE will take to reconfigure on receiving the message, it has to assume the worst-case. Thus, it typically indicates a conservative activation time, leading to potentially large interruption for voice traffic, particularly if the source cell signal strength has degraded. This proposals allow the UE to receive the serving cell related information (carried today in PCR/RBR/TCR message) in an Active Set Update message.

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The Interaction of Vortex and Premixed Flame with Consideration of Volume Expansion Effect (체적팽창효과를 고려한 예혼합화염과 와동의 상호작용에 관한 연구)

  • Jeong Ui-Heon;Gwon Se-Jin
    • 한국전산유체공학회:학술대회논문집
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    • 1998.11a
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    • pp.204-210
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    • 1998
  • A method is developed to include the effect of volume expansion in the description of the flame dynamics using G-equation. Line volume-source is used to represent the effect of the exothermic process of combustion with source strength determined by the density difference between the burned and the unburned region. Volume expansion adjusts the flow field to accommodate the increased volume flow rate crossing the flame front. Test result predicted the measured velocity field qualitatively. The method was applied to study the interaction of vortex and premixed flame. Increased volume expansion did not change the initial growth rate of flame area. However, the residence time and flame surface area increased with higher expansion ratios.

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Identification of Interior Noise Sources by Using Reconstruction of Active Sources and Surface Admittance (능동음원 및 벽면 어드미턴스의 재구성을 통한 실내 소음원의 정확한 규명 방법)

  • 김영기;김양한
    • Journal of KSNVE
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    • v.8 no.3
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    • pp.435-440
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    • 1998
  • The main objective of this study is to estimate location and strength of sound sources distributed on the surface of an enclosure. Acoustic holography method has been used to identify the sources in an interior sound field. However, it can not completely distinguish between the direct sound field from sources and the reflections from surfaces. The method just reconstructs the entire sound field based on the sound pressure at the finite number of measurement points. In this stduy, a method which estimates only the active sources by using measurements of field pressure and surface admittance is proposed. An in-situ technique to estimate the general boundary condition is also proposed by using acoustic holography, assuming the surfaces are locally reacting.

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The Interaction of Vortex and Premixed Flame with Consideration of Volume Expansion Effect (체적팽창효과를 고려한 예혼합화염과 와동의 상호작용에 관한 연구)

  • Chung, Eui-Heon;Kwon, Se-jin
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.22 no.12
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    • pp.1669-1680
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    • 1998
  • A method is developed to include the effect of volume expansion in the description of the flame dynamics using G-equation. Line volume-source is used to represent the effect of the exothermic process of combustion with source strength assigned by the density difference between the burned and the unburned region. The present model provides good agreement with the experimental results. Including volume expansion, the flow field is adjusted to accommodate the increased volume flow rate which crossing the flame front and the result predicts the same behavior of measured velocity field qualitatively. The effect of increasing volume expansion does not change the initial growth rate of flame area but increase the residence time. Consequently this effect increases the maximum area of flame front. The flame propagation in varying flow field due to volume expansion provides a promising way to represent the wrinkled turbulent premixed flames in a numerically efficient manner.

Simulation and Measurement of Characteristic in 450 mm CCP Plasma Source

  • Park, Gi-Jeong;Seo, Sang-Hun;Jang, Hong-Yeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.508-508
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    • 2012
  • CST microwave studio is used to simulate the plasma profile of the 450mm CCP source. Standing wave effect becomes important at the high frequency as the electrode radius increases. To solve plasma non-uniformity problem, we designed multi electrode chamber to decreasing standing wave effect. Simulation showed the ratio of input power of each electrode is related with electric field strength. The multi electrode was constructed and measured by 2D probe arrays using floating harmonic method. Uniformity of 450 mm CCP was changed by the ratio of input power of each electrode. We described this dependence with circuit model.

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Analysis of Noise Source for Mold Transformer (몰드변압기의 소음 원인 분석)

  • Choi, W.H.;Kim, W.C.
    • Journal of Power System Engineering
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    • v.4 no.4
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    • pp.59-64
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    • 2000
  • Especially, demands for the noise reduction of mold transformer has been becoming an common issue because it has been used mainly at the residence area such as building and ship. So, this paper investigates the noise source and countermeasure of mold transformer radiated high noise abnormally. The result of impact hammering test for core of transformer ascertains the core resonance by harmonics of line frequency and high noise can be reduced to avoid core resonance by changing torque strength of tie rod. Magnetic field analysis is performed to identify the reason that noise of V-phase is higher than U and W-phase in the normal condition. It is the cause that flux density and magnetic force of V-phase is higher than the other phase respectively.

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