• 한국지리정보학회지
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• 제6권2호
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• pp.33-45
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• 2003

이 연구는 객체지향 지리정보시스템을 이용하여 지리-객체와 지리-필드를 연결하는 지리-객체필드 방법을 규정하고, 수계-객체필드를 이용하여 새만금호 수량과 배수갑문수위를 조작하는 새만금수자원관리시스템의 홍수 시뮬레이션을 구현하고자 한다. 그리고 새만금 수계 수자원에 발생하는 자연현상과 인공현상을 조합하여 하나의 전체 수계-객체필드로 구성되는 객체지향 클래스 계층구조를 설계함으로써 홍수통제 알고리즘 기법을 제안하고자 한다. 동시에 UML을 이용하여 전체적인 지리-객체필드와 단계적인 부분 지리-객체필드의 클래스계층구조를 가시화하고자 하며, 각 클래스의 속성과 메소드는 ZEUS/COM과 Win32 API을 이용한 Visual Basic 6.0을 사용함으로써 각각 호환성과 재사용성 기능을 확보하고자 한다. 이 논문은 새만금수자원관리시스템을 구현함으로써 효율적인 물관리를 하는데 기여할 수 있을 것이다.

• 한국전산유체공학회지
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• 제10권1호
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• pp.56-62
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• 2005

Large eddy simulation of vortexing flow of molten steel in the continuous casting mold with and without DC magnetic field was conducted. The influence of the position of magnetic field to the residence time and depth of the vortex was analyzed. The mechanism of the influence of magnetic field to the vortexing flow was found. The computational results show that the vortexing flow is the result of shearing of the two un-symmetric surface flows from the mold narrow faces when they meet adjacent to the SEN; the un-symmetric flow for turbulent vortex is caused by turbulent energy of the fluid and that for biased vortex is caused by biased flow and the turbulent energy of fluid; with the moving of the magnetic field from the centerline of the outlet of the SEN to the free surface, the surface velocity is decreased gradually and the depth of the turbulent vortex and the biased vortex is decreased, the residence time is increased with the magnetic field moves from DL=120mm to DL=60mm and then decreased; the turbulent vortex and the biased vortex can be eliminated when the magnetic field is located at the free surface.

• 한국멀티미디어학회논문지
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• 제17권9호
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• pp.1104-1114
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• 2014

In large-scale crowd simulations, it is very important for the decision-making system of manipulating interactive behaviors to minimize the computational cost for controlling realistic behaviors such as collision avoidance. In this paper, we propose a large-scale realtime crowd simulation method using the affordance and navigation potential fields such as attractive and repulsive forces of electromagnetic fields. In particular, the model that we propose locally handles the realistic interactions between agents, and thus radically reduces the cost of expensive computation on interactions which has been the most problematic in crowd simulation. Our method is widely applicable to the expression and analysis of various crowd behaviors that are needed in behavior control in computer games, crowd scenes in movies, emergent behaviors of evacuation, etc.

• 한국컴퓨터그래픽스학회논문지
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• 제14권4호
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• pp.1-5
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• 2008

본 논문은 유체 시뮬레이션의 격자 내 상세도를 와류입자법(Vortex Particle Method)를 사용하여 향상시킬 수 있는 새로운 방법을 제안한다. 비압축 Navier-Stokes 방정식을 풀어 낸 속도장(Velocity Field)으로 유체의 거시적인 움직임을, 와류입자법으로 생성한 와도장(Vorticity Field)으로 유체의 미세한 움직임을 표현한다. 이 기법은 고해상도 격자에서 선형시스템을 풀지 않기 때문에 고해상도 유체 시뮬레이션을 효율적으로 할 수 있고, 강한 난류 효과를 만들어 낼 수 있다.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제20권1호
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• pp.37-50
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• 2016

A large eddy simulation (LES) of a turbulent channel flow is performed by using the third order low-storage Runge-Kutta method in time and second order finite difference formulation in space with staggered grid at a Reynolds number, $Re_{\tau}=590$ based on the channel half width, ${\delta}$ and wall shear velocity, $u_{\tau}$. To reduce the calculation cost of LES, algebraic wall model (AWM) is applied to approximate the near-wall region. The computation is performed in a domain of $2{\pi}{\delta}{\times}2{\delta}{\times}{\pi}{\delta}$ with $32{\times}20{\times}32$ grid points. Standard Smagorinsky model is used for subgrid-scale (SGS) modeling. Essential turbulence statistics of the flow field are computed and compared with Direct Numerical Simulation (DNS) data and LES data using no wall model. Agreements as well as discrepancies are discussed. The flow structures in the computed flow field have also been discussed and compared with LES data using no wall model.

• 한국유체기계학회 논문집
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• 제4권3호
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• pp.14-20
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• 2001

Numerical analysis of the three dimensional turbulent flow field in a complex valve trim is carried out to confirm the possibility whether this simulation tool can be used as a design tool or not. The simulation of the incompressible flow in a glove valve is performed by using the commercial code. CFD-ACEA utilizes the finite volume approach as a discretization scheme, and the pressure-velocity coupling is made from SIMPLEC algorithm in it. Four flow cases of the control valve are investigated, and the valve flow coefficient for each case is compared with the experimental data. Simulation results show a good agreement with the experiments, and it is observed that the cavitation model improves the simulation results.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2010년 춘계학술대회논문집
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• pp.2-4
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• 2010

Due to rapid progress in the performance of high-end computers, numerical prediction of fluid flow and flow-induced sound is expected to become a vital tool for aero- and hydro- dynamic design of various flow-related products. This presentation focuses on the applications of large-scale numerical simulations to complex engineering problems with a particular emphasis placed on the low-speed flows. Flow field computations are based on a large eddy simulation that directly computes all active eddies in the flow and models only those eddies responsible for energy dissipations. The sound generated from low-speed turbulent flows are computed either by direct numerical simulation or by decoupled methods, according to whether or not the feedback effects of the generated sound onto the source flow field can be neglected. Several numerical examples are presented in order to elucidate the present status of such computational methods and discussion on the future prospects will also be given.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.93-93
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• 2010

In this talk, I will introduce a reactive force field (ReaxFF) molecular dynamics (MD) simulation. In contrast to common MD simulations with empirical FFs, we can predict chemical reactions (bond breaking and formation) in large scale systems with the ReaxFF simulation where all of the ReaxFF parameters are from quantum mechanical calculations such as density functional theory to provide high accuracy. Accordingly, the ReaxFF simulation provides both accuracy of quantum mechanical calculations and description of large scale systems of atomistic simulations at the same time. Here, I will first discuss a theory in the ReaxFF including the differences from other empirical FFs, and then show several applications for studying chemical reactions of SiHx radicals on Si surfaces, which is an important issue in Si process.

• 대한한의진단학회지
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• 제13권2호
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• pp.140-148
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• 2009

The primary market of acupuncture treatment is concentrated on disorders of the musculoskeletal system. This study researches the clinical use of the musculoskeletal system evaluation with a computer simulation. Two fields are examined - patient evaluation and patient treatment. In the field of evaluation, the simulation is used to evaluates the prognosis of medical treatment. In the field of treatment, the simulation is used to decide the most suitable way to perform surgery using the quantitative evaluation about various cases of surgical results.

• 한국군사과학기술학회지
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• 제7권1호
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• pp.69-76
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• 2004

When simulating the mission flight of a fighter equipped with the avionic ECM pod, it is massively required to provide the correct information of threats, to depict the real environment of mission area, and to precisely model the capability of the ECM system. Also, in order to get the reliable results of those simulation, it should be supported the flexible changes of threat environments and the examination of multiple flight paths. This paper presents a software system which is possible to flexible and interactive ECM simulation. This system has capable of the 2D or 3D visualization of virtual battle field, the management of electronic threat data, and the simulation of engagement model.