• Title/Summary/Keyword: paper conservation

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TWO-DIMENSIONAL RIEMANN PROBLEM FOR BURGERS' EQUATION

  • Yoon, Dae-Ki;Hwang, Woon-Jae
    • Bulletin of the Korean Mathematical Society
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    • v.45 no.1
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    • pp.191-205
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    • 2008
  • In this paper, we construct the analytic solutions and numerical solutions for a two-dimensional Riemann problem for Burgers' equation. In order to construct the analytic solution, we use the characteristic analysis with the shock and rarefaction base points. We apply the composite scheme suggested by Liska and Wendroff to compute numerical solutions. The result is coincident with our analytic solution. This demonstrates that the composite scheme works pretty well for Burgers' equation despite of its simplicity.

A Verification of the Numerical Energy Conservation Property of the FD-TD(Finite Difference-Time Domain) Method by Using a Plane Wave Analysis (평면파 해석을 이용한 시간영역-유한차분법의 수치적 에너지 보존성질의 증명)

  • Ihn-Seok Kim
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.7 no.4
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    • pp.320-327
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    • 1996
  • This paper presents that the lossy or amplification property of the Finite Difference-Time Domain(FD-TD) method based on the leap-frog scheme is theoretically verified by using a plane wave analysis. The basic algorithm of the FD-TD method is introduced in order to help understanding the analysis procedure. Since our analysis is formulated by the Von Neumann's approach, the stability inequality is also produced as an another outcome.

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A Benefit-Cost Analysis on the DSM Programs Part I (DSM 프로그램의 비용효과 분석 I)

  • Hwang, Sung-Wook;Kim, Bal-Ho;Kim, Jung-Hoon;Park, Jong-Bae
    • Proceedings of the KIEE Conference
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    • 2000.11a
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    • pp.46-48
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    • 2000
  • This paper presents an approach to B/C analysis amenable to evaluate the impact of DSM programs especially on the strategic conservation programs and the load management programs. The proposed approach embedding the existing B/C analyses is applicable to the new electricity market Case studies show the B/C ratio and the avoided cost due to the impact of DSM programs.

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A Benefit-Cost Analysis on the DSM Programs Part II (DSM 프로그램의 비용효과 분석 II)

  • Park, Jong-Bae;Kim, Jin-Ho;Hwang, Sung-Wook;Kim, Bal-Ho
    • Proceedings of the KIEE Conference
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    • 2000.11a
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    • pp.190-192
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    • 2000
  • This paper presents an approach to B/C analysis amenable to evaluate the impact of DSM programs especially on the strategic conservation programs and the load management programs. The proposed approach embedding the existing B/C analyses is applicable to the new electricity market. Case studies show the B/C ratio and the avoided cost due to the impact of DSM programs.

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An Overview of the Long-Term Ecological Research(LTER) Activities in Korea

  • Kim, Eun-Shik
    • The Korean Journal of Ecology
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    • v.23 no.2
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    • pp.75-81
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    • 2000
  • This paper was prepared to have an overview of the Long-Term Ecological Research (LTER ) activities in Korea in order to facilitate further development of Korea LTER Network in the coming 21th century. After the background for the development of the Korea LTER network was reviewed, the network activities of Korea as well as of the world were introduced for sound management and conservation of ecosystems, which can be ultimately carried out by the long-term ecological researches whose results can secure comparability in the dimension of time and space.

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NEWTONIAN COSMOLOGICAL PERTURBATIONS

  • Hwang, Jai-Chan
    • Publications of The Korean Astronomical Society
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    • v.7 no.1
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    • pp.107-148
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    • 1992
  • This paper presents a cosmological perturbation analysis in a Newtonian framework, using the Newtonian multi component version of the relativistic covariant equations. This work considers the fully nonlinear evolution of the perturbations, and is generalized to multicomponent systems and imperfect fluids. Known nonlinear solutions are presented in a general framework. Quasi-nonlinear analysis, considering both the compressible and rotational modes, is presented, including cases already known in the literature. The Fourier space representation of the conservation equations is also derived in a general context, with various decompositions of the velocity field. Commonly accepted cosmogonical frameworks are critically examined in the context of nonlinear evolution. This work may be regarded as the Newtonian counterpart of a recently presented general relativistic covariant formulation.

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NOTES FOR AUTHORS OF THE KOREAN SOCIETY OF COMPUTATIONAL FLUIDS ENGINEERING (고차 내삽기법을 사용한 중첩 격자기법)

  • Lee, K.L.;Kim, K.H.
    • 한국전산유체공학회:학술대회논문집
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    • 2007.10a
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    • pp.209-213
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    • 2007
  • This paper presents the high order conservative interpolation methods. This method has been successfully implemented into a cell-centered finite volume methods code. Results using high order and maintaining conservation interpolation method are more accurate compared to bilinear interpolation.

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Recommended Practice for the Improvement of the Unit Cost of Power Consumption in Non-utility Electrical Installation (자가용전기설비의 전력원단위 향상을 위한 전력관리 방안)

  • 김세동
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2000.11a
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    • pp.235-240
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    • 2000
  • This paper presents the reasonable method for electric power management through efficient use of electricity. With a rapid of national economics and living standard, electrical energy consumption markedly increased. Especially it is increased electrical energy consumption in commercial buildings and thus an energy conservation through efficient use of electricity became more important.

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TRAFFIC FLOW MODELS WITH NONLOCAL LOOKING AHEAD-BEHIND DYNAMICS

  • Lee, Yongki
    • Journal of the Korean Mathematical Society
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    • v.57 no.4
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    • pp.987-1004
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    • 2020
  • Motivated by the traffic flow model with Arrhenius looka-head relaxation dynamics introduced in [25], this paper proposes a traffic flow model with look ahead relaxation-behind intensification by inserting look behind intensification dynamics to the flux. Finite time shock formation conditions in the proposed model with various types of interaction potentials are identified. Several numerical experiments are performed in order to demonstrate the performance of the modified model. It is observed that, comparing to other well-known macroscopic traffic flow models, the model equipped with look ahead relaxation-behind intensification has both enhanced dispersive and smoothing effects.

Numerical Analysis of the Effect of Injection Pressure Variation on Spray Characteristics (분사압력변화가 분무특성에 미치는 영향에 관한 수치적 고찰)

  • Park K.
    • 한국전산유체공학회:학술대회논문집
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    • 1997.10a
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    • pp.113-119
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    • 1997
  • This paper addresses to the injection pressure effect on the diesel spray. The injection pressure is varied from 10MPa, in general system, upto 200MPa, in high pressured system in order to understand the effect. The gas phase is modelled in terms of the Eulerian continuum conservation equations of mass, momentum, energy and fuel vapour fraction. The liquid phase is modelled following the discrete droplet model approach in Lagrangian form. The droplet distributions, vapor fractions and gas flows are analyzed in various injection pressure cases.

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