• Title/Summary/Keyword: volume source

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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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SMOLED equipment for Mass-production

  • Kim, Chang-Woo;Cho, Woo-Seok;Kim, Dong-Soo;Bae, Kyung-Bin
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.133-136
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    • 2002
  • It is very important to get a stable and large-capacity organic effusion source for achievement of OLED mass-production equipment. We present an organic effusion source with film uniformity less than ${\pm}$ 5%, the material charge volume, 300cc for $400{\times}400\;mm^2$ substrate. The fine metal shadow mask alignment technology, one of the color forming technique, also have to support more accurate and fast operating in mass-production. In this paper, we will describe the OLED mass-production equipment with the large volume effusion source and the precision shadow mask alignment technique.

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Temperature Evaluation on Long-term Storage of Radioactive Waste Produced in the Process of Isotope Production (동위원소 생산공정에서 발생한 방사성 폐기물 장기저장소 온도평가)

  • Jeong, Namgyun;Jo, Daeseong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.40 no.7
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    • pp.471-475
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    • 2016
  • In the present study, temperature evaluations on long-term storage of radioactive waste produced in the process of isotope production were performed using two different methods. Three-dimensional analysis was carried out assuming a volumetric heat source, while two-dimensional studies were performed assuming a point source. The maximum temperature difference between the predictions of the volumetric and point source models was approximately $5^{\circ}C$. For the conceptual design level, a point source model may be suitable to obtain the overall temperature characteristics of different loading locations. For more detailed analysis, the model with the volumetric source may be applicable to optimize the loading pattern in order to obtain minimum temperatures.

Review on the divergence form for bed slope source term and correction of the volume/free-surface relationship (발산형 바닥 경사 생성항의 재검토와 체적-수위 관계의 수정)

  • Hwang, Seung-Yong
    • Journal of Korea Water Resources Association
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    • v.50 no.5
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    • pp.289-302
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    • 2017
  • DFB (Divergence Form for Bed slope source term) was rigorously derived and the error of mDFB using mean water depth at the cell face in DFB was clearly demonstrated. In addition, DFB technique turned out to be an exact method to the bed slope source term. The existing volume/free-surface relationship to the PSC (Partially Submerged Cell) has been corrected. It was discussed that treatment for the partially submerged edge is required to satisfy the C-property in PSC. It is expected that this study will provides a more accurate means in analyzing the shallow water equations with the approximate Riemann solver.

Evaluate the usefulness of Coincidence Summing Correction Factors for Cylinder and Extended Source Penelope Simulation (실린더 및 확장 소스 PENELOPE 시뮬레이션에 대한 동시합성보정 계수 유용성 평가)

  • Jang, Eun-Sung;Chang, Bo-Seok
    • Journal of the Korean Society of Radiology
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    • v.15 no.6
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    • pp.821-831
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    • 2021
  • In order to calibrate energy and efficiency using the PENELOPE Code, a PENELOPE simulation was performed using a volume source. Here, we want to verify peak efficiency and usefulness by performing simultaneous measurement and correction. calculate the coincident sum correction for all volumes, first subdivide the volumes of the cylinder and the four Marinelli beakers into three heights again. Therefore, the simultaneous measurement correction coefficient in three areas and the simultaneous measurement correction coefficient for the entire volume source are calculated as output. At low energies, the j value for each source volume (50-300 ml) is small and increases significantly in the high energy range. Simulation results showed good agreement within 2.5% for all source volumes except for 50 ml and 300 ml, which were up to 4%. This means that the correction for the simultaneous measurement effect during measurement is effective. In addition. Based on this, it can be confirmed that there is an advantage to improve the detection efficiency when measuring various sources and environmental samples.

Visualization Techniques for Massive Source Code (대용량 소스코드 시각화기법 연구)

  • Seo, Dong-Su
    • The Journal of Korean Association of Computer Education
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    • v.18 no.4
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    • pp.63-70
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    • 2015
  • Program source code is a set of complex syntactic information which are expressed in text forms, and contains complex logical structures. Structural and logical complexity inside source code become barriers in applying visualization techniques shown in traditional big-data approaches when the volume of source code become over ten-thousand lines of code. This paper suggests a procedure for making visualization of structural characteristics in source code. For this purpose, this paper defines internal data structures as well as inter-procedural relationships among functions. The paper also suggests a means of outlining the structural characteristics of source code by visualizing the source codes with network forms The result of the research work can be used as a means of controling and understanding the massive volume of source code.

NEW TECHNIQUE IN THE USE OF VIBRO-ACOUSTICAL RECIPROCITY WITH APPLICATION TO THE NOISE TRANSFER FUNCTION MEASUREMENT

  • Ko, K.H.;Kook, H.S.;Heo, S.J.
    • International Journal of Automotive Technology
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    • v.7 no.2
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    • pp.173-177
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    • 2006
  • A noise transfer function(NTF) is the frequency response function between an input force applied to an exterior point of a vehicle body and the resultant interior sound pressure usually measured at the driver's ear position. It represents the measure of noise sensitivity for the output force transmitted to the joints between the body and chassis. The principle of vibro-acoustic reciprocity is often utilized in the measurement of NTF. One difficulty in using the volume source is that most of the previously proposed methods require the knowledge of the volume velocity of the acoustic source in advance. A new method proposed in the present work does not require any calculation related with the volume velocity of the acoustic source, but still yields even more accurate results both in the amplitude and phase of the NTF. In the present work, the new method is applied to obtain NTF data for a midsize sedan.

Study on Source Waye hnalysis in Crack Growth by AE Method (AE법(法)에 의한 균열성장의 Source Wave해석(解析)에 관(關)한 연구(硏究))

  • Han, Eung-Kyo;Kim, Tong-Kyu;Choi, Man-Yong;Kim, Kyung-Suk
    • Journal of the Korean Society for Nondestructive Testing
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    • v.3 no.2
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    • pp.5-12
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    • 1984
  • The purpose of this paper is to decide volume of crack by AE source wave analysis. The material studied in this paper was Titanium Alloy. Transient wave memory has 50 nano sampling time. The response function of specimens and transducer was obtained experimentally by use of specimens and transducer was obtained experimentally by use of breaking pencil lead as a reference simulated AE source, and the source waves were dertermined in terms of energy release-time functions explicitly through a time domain deconvolution. From experimental results, we can determine size of cracked volume.

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An Immersed-Boundary Finite-Volume Method for Simulation of Heat Transfer in Complex Geometries

  • Kim, Jungwoo;Park, Haecheon
    • Journal of Mechanical Science and Technology
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    • v.18 no.6
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    • pp.1026-1035
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    • 2004
  • An immersed boundary method for solving the Navier-Stokes and thermal energy equations is developed to compute the heat transfer over or inside the complex geometries in the Cartesian or cylindrical coordinates by introducing the momentum forcing, mass source/sink, and heat source/sink. The present method is based on the finite volume approach on a staggered mesh together with a fractional step method. The method of applying the momentum forcing and mass source/sink to satisfy the no-slip condition on the body surface is explained in detail in Kim, Kim and Choi (2001, Journal of Computational Physics). In this paper, the heat source/sink is introduced on the body surface or inside the body to satisfy the iso-thermal or iso-heat-flux condition on the immersed boundary. The present method is applied to three different problems : forced convection around a circular cylinder, mixed convection around a pair of circular cylinders, and forced convection around a main cylinder with a secondary small cylinder. The results show good agreements with those obtained by previous experiments and numerical simulations, verifying the accuracy of the present method.

Optimal Volume Estimation for Non-point Source Control Retention Considering Spatio-Temporal Variation of Land Surface (지표면의 시공간적 변화를 고려한 비점오염원 저감 저류지 최적용량산정)

  • Choi, Daegyu;Kim, Jin Kwan;Lee, Jae Kwan;Kim, Sangdan
    • Journal of Korean Society on Water Environment
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    • v.27 no.1
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    • pp.9-18
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    • 2011
  • In this study the optimal volume for non-point source control retention is estimated considering spatio-temporal variation of land surface. The 3-parameter mixed exponential probability density function is used to represent the statistical properties of rainfall events, and NRCS-CN method is applied as rainfall-runoff transformation. The catchment drainage area is divided into individual $30m{\times}30m$ cells, and runoff curve number is estimated at each cell. Using the derived probability density function theory, the stormwater probability density function at each cell is derived from the rainfall probability density function and NRCS-CN rainfall-runoff transformation. Considering the antecedent soil moisture condition at each cell and the spatial variation of CN value at the whole catchment drainage area, the ensemble stormwater capture curve is established to estimate the optimal volume for an non-point source control retention. The comparison between spatio-temporally varied land surface and constant land surface is presented as a case study for a urban drainage area.