• Title/Summary/Keyword: computational model

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Computational Science-based Research on Dark Matter at KISTI

  • Cho, Kihyeon
    • Journal of Astronomy and Space Sciences
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    • v.34 no.2
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    • pp.153-159
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    • 2017
  • The Standard Model of particle physics was established after discovery of the Higgs boson. However, little is known about dark matter, which has mass and constitutes approximately five times the number of standard model particles in space. The cross-section of dark matter is much smaller than that of the existing Standard Model, and the range of the predicted mass is wide, from a few eV to several PeV. Therefore, massive amounts of astronomical, accelerator, and simulation data are required to study dark matter, and efficient processing of these data is vital. Computational science, which can combine experiments, theory, and simulation, is thus necessary for dark matter research. A computational science and deep learning-based dark matter research platform is suggested for enhanced coverage and sharing of data. Such an approach can efficiently add to our existing knowledge on the mystery of dark matter.

ACCURACY IMPROVEMENT OF THE BLEED BOUNDARY CONDITION WITH THE EFFECTS OF POROSITY VARIATIONS AND EXPANSION WAVES (다공도 및 팽창파의 영향을 고려한 BLEED 경계조건 수치 모델링의 정확도 향상 연구)

  • Kim, G.;Choe, Y.;Kim, C.
    • Journal of computational fluids engineering
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    • v.21 no.1
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    • pp.94-102
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    • 2016
  • The present paper deals with accuracy improvement of a bleed boundary condition model used to improve the performance of supersonic inlets. In order to accurately predict the amount of bleed mass flow rates, this study performs a scaling of sonic flow coefficient data for 90-degree bleed holes in consideration of Prandtl-Meyer expansion theory. Furthermore, it is assumed that porosity varies with stream-wise location of the porous bleed plate to accurately predict downstream boundary layer profiles. The bleed boundary condition model is demonstrated through Computational Fluid Dynamics(CFD) simulations of bleed flows on a flat plate with/without an oblique shock. As a result, the bleed model shows the improved accuracy of bleed mass rates and downstream boundary layer profiles.

EVELOPMENT OF AXISYMMETRIC MULTI-SPECIES GH EQUATION FOR HYPERSONIC RAREFIED FLOW ANALYSES (극초음속 희박유동 해석을 위한 축대칭 다화학종 GH 방정식의 개발)

  • Ahn, J.W.;Kim, C.
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03a
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    • pp.84-91
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    • 2008
  • Generalized hydrodynamic (GH) theory for multi-species gas and the computational models are developed for the numerical simulation of hypersonic rarefied gas flow on the basis of Eu's GH theory. The rotational non-equilibrium effect of diatomic molecules is taken into account by introducing excess normal stress associated with the bulk viscosity. The numerical model for the diatomic GH theory is developed and tested. Moreover, with the experience of developing the dia-tomic GH computational model, the GH theory is extended to a multi-species gas including 5 species; O$_2$, N$_2$, NO, O, N. The multi-species GH model includes diffusion relation due to the molecular collision and thermal phenomena. Two kinds of GH models are developed for an axisymmetric flow solver. By compar-ing the computed results of diatomic and multi-species GH theories with those of the Navier-Stokes equations and the DSMC results, the accuracy and physical consistency of the GH computational models are examined.

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EVELOPMENT OF AXISYMMETRIC MULTI-SPECIES GH EQUATION FOR HYPERSONIC RAREFIED FLOW ANALYSES (극초음속 희박유동 해석을 위한 축대칭 다화학종 GH 방정식의 개발)

  • Ahn, J.W.;Kim, C.
    • 한국전산유체공학회:학술대회논문집
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    • 2008.10a
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    • pp.84-91
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    • 2008
  • Generalized hydrodynamic (GH) theory for multi-species gas and the computational models are developed for the numerical simulation of hypersonic rarefied gas flow on the basis of Eu's GH theory. The rotational non-equilibrium effect of diatomic molecules is taken into account by introducing excess normal stress associated with the bulk viscosity. The numerical model for the diatomic GH theory is developed and tested. Moreover, with the experience of developing the dia-tomic GH computational model, the GH theory is extended to a multi-species gas including 5 species; $O_2,\;N_2$, NO, O, N. The multi-species GH model includes diffusion relation due to the molecular collision and thermal phenomena. Two kinds of GH models are developed for an axisymmetric flow solver. By compar-ing the computed results of diatomic and multi-species GH theories with those of the Navier-Stokes equations and the DSMC results, the accuracy and physical consistency of the GH computational models are examined.

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Education Course Model based on AP CSP For Improvement of Computational Thinking

  • Cheon, EunYoung
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.9
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    • pp.171-178
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    • 2019
  • Computational Thinking is one of the biggest issues in the era of the Fourth Industrial Revolution. It is a core literacy required not only for SW major but also for all students including them. It is not a simple computer software education, but a coding education based on Computational Thinking, and it should be able to solve the problems in everyday life and to express the process and solutions. However, in the case of students who lack background knowledge on SW and programming languages for development, it is hard to know how to algorithmize problems and express them using computer devices. In this study, we proposed a education course model to improve the students' thinking skills and to express them effectively. In addition, we confirmed whether the non-major students who learned through this education course model can express various problems related to the major field by integrating them with computing accidents and improve the problem solving ability.

Maneuvering Target Tracking Using Multiresolutional Interacting Multiple Model Filter

  • Yu, C,H.;Choi, J.W.;Song, T.L.
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.2340-2344
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    • 2003
  • This paper considers a tracking filter algorithm which can track a maneuvering target. Multiresolutional Interacting Multiple Model (MRIMM) algorithm is proposed to reduce computational burden. In this paper multiresolutional state space model equation and multiresolutional measurement equation are derived by using wavelet transform. This paper shows the outline of MRIMM algorithm. Simulation results show that MRIMM algorithm maintains a good tracking performance and reduces computational burden.

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다양한 구조설계 과정의 표현을 위한 모델의 필요성

  • 이창호
    • Computational Structural Engineering
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    • v.11 no.2
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    • pp.40-48
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    • 1998
  • 본 기사에서는 간단한 구조물에 대한 구조설계과정의 예에 대하여 살펴보았다. 구조설계 과정은 MSD model의 개념을 이용하여 표시하였다. 그러나 MSD model은 구체적인 설계과정의 표기법을 포함하지는 않는다. 실제의 구조설계 과정은 본 기사에서 나타난 것보다는 더욱 복잡하고, 이를 위하여 질서정연하게 구조설계과정을 표시할 수 있는 표기법을 가진 model이 필요하게 된다. 지금까지 여러 연구자들에 의하여 설계과정의 다양성을 표현하기 위한 model들이 제안되어 왔으며, 본 기사에서 설명된 MSD model과 관련된 것으로는 Context-Free Grammar를 이용한 설계과정 표기법이 있다. 이 표기법은 개체형 통합설계모델의 일부로서 개발되었다.

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Equivalent Continuum Model for the Single Wall Carbon Nanotube (Single Wall Carbon Nanotube의 등가 연속체 모델에 대한 연구)

  • 김병구;전흥재
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.04a
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    • pp.227-234
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    • 2003
  • In this study, an equivalent continuum model for single wall carbon nanotube is proposed. The model links interatomic potentials and atom structure of a materials to a constitutive model on the continuum level. The Young's modulus and shear modulus were predicted by the model. The predictions were in good agreement with the prior experimental results available in the literatures. Also, the strain energy of the carbon nanotube was predicted as a function of the radius of the carbon nanotube.

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Computational Model for Hydrodynamic Pressure on Radial Gates during Earthquakes (레디얼 게이트에 작용하는 지진 동수압 계산 모형)

  • Phan, Hoang Nam;Lee, Jeeho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.32 no.5
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    • pp.323-331
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    • 2019
  • In this study, a computational model approach for the modeling of hydrodynamic pressures acting on radial gates during strong earthquakes is proposed. The use of the dynamic layering method with the Arbitrary Lagrangian Eulerian (ALE) algorithm and the SIMPLE method for simulating free reservoir surface flow in addition to moving boundary interfaces between the fluid domain and a structure due to earthquake excitation are suggested. The verification and validation of the proposed approach are realized by comparisons performed using the renowned formulation derived by the experimental results for vertical and inclined dam surfaces subjected to earthquake excitation. A parameter study for the truncated lengths of the two-dimensional fluid domain demonstrates that twice the water level leads to efficient and converged computational results. Finally, numerical simulations for large radial gates with different curvatures subjected to two strong earthquakes are successfully performed using the suggested computational model.

Application and Effect Analysis of ARCS Model to Improve Learner's Learning Motivation in Liberal Computational Thinking Subjects (교양 컴퓨팅 사고력 과목의 학습자 학습동기 향상을 위한 ARCS 모델의 적용 및 효과 분석)

  • Jun, Soo-jin;Shin, ChwaCheol
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.24 no.2
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    • pp.259-267
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    • 2020
  • The purpose of this study is to analyze the effects of computational thinking class using ARCS model to increase students' learning motivation. Then, this study designed the detailed instruction strategy according to each motivation factor(Attention, Relevance, Confidence, Satisfaction) of ARCS through the previous study on computational thinking education and ARCS model. The results of the ARCS test were compared between the experimental group to which the ARCS model was applied and the control group to which the general class was conducted. As a result, students in the experimental group showed significantly higher motivation for learning about computational thinking. In particular, the learning motivation of computer-related majors was significantly higher than that of the control group. In addition, majors were found to have high relevance(R) and non-majors had high satisfaction(S). Therefore, based on these findings, this study suggests an improvement for effective computational thinking class in liberal arts education.